]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * kernel/sched.c | |
3 | * | |
4 | * Kernel scheduler and related syscalls | |
5 | * | |
6 | * Copyright (C) 1991-2002 Linus Torvalds | |
7 | * | |
8 | * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and | |
9 | * make semaphores SMP safe | |
10 | * 1998-11-19 Implemented schedule_timeout() and related stuff | |
11 | * by Andrea Arcangeli | |
12 | * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: | |
13 | * hybrid priority-list and round-robin design with | |
14 | * an array-switch method of distributing timeslices | |
15 | * and per-CPU runqueues. Cleanups and useful suggestions | |
16 | * by Davide Libenzi, preemptible kernel bits by Robert Love. | |
17 | * 2003-09-03 Interactivity tuning by Con Kolivas. | |
18 | * 2004-04-02 Scheduler domains code by Nick Piggin | |
c31f2e8a IM |
19 | * 2007-04-15 Work begun on replacing all interactivity tuning with a |
20 | * fair scheduling design by Con Kolivas. | |
21 | * 2007-05-05 Load balancing (smp-nice) and other improvements | |
22 | * by Peter Williams | |
23 | * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith | |
24 | * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri | |
b9131769 IM |
25 | * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, |
26 | * Thomas Gleixner, Mike Kravetz | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/mm.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/nmi.h> | |
32 | #include <linux/init.h> | |
dff06c15 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | #include <linux/highmem.h> |
35 | #include <linux/smp_lock.h> | |
36 | #include <asm/mmu_context.h> | |
37 | #include <linux/interrupt.h> | |
c59ede7b | 38 | #include <linux/capability.h> |
1da177e4 LT |
39 | #include <linux/completion.h> |
40 | #include <linux/kernel_stat.h> | |
9a11b49a | 41 | #include <linux/debug_locks.h> |
0d905bca | 42 | #include <linux/perf_counter.h> |
1da177e4 LT |
43 | #include <linux/security.h> |
44 | #include <linux/notifier.h> | |
45 | #include <linux/profile.h> | |
7dfb7103 | 46 | #include <linux/freezer.h> |
198e2f18 | 47 | #include <linux/vmalloc.h> |
1da177e4 LT |
48 | #include <linux/blkdev.h> |
49 | #include <linux/delay.h> | |
b488893a | 50 | #include <linux/pid_namespace.h> |
1da177e4 LT |
51 | #include <linux/smp.h> |
52 | #include <linux/threads.h> | |
53 | #include <linux/timer.h> | |
54 | #include <linux/rcupdate.h> | |
55 | #include <linux/cpu.h> | |
56 | #include <linux/cpuset.h> | |
57 | #include <linux/percpu.h> | |
58 | #include <linux/kthread.h> | |
b5aadf7f | 59 | #include <linux/proc_fs.h> |
1da177e4 | 60 | #include <linux/seq_file.h> |
e692ab53 | 61 | #include <linux/sysctl.h> |
1da177e4 LT |
62 | #include <linux/syscalls.h> |
63 | #include <linux/times.h> | |
8f0ab514 | 64 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 65 | #include <linux/kprobes.h> |
0ff92245 | 66 | #include <linux/delayacct.h> |
dff06c15 | 67 | #include <linux/unistd.h> |
f5ff8422 | 68 | #include <linux/pagemap.h> |
8f4d37ec | 69 | #include <linux/hrtimer.h> |
30914a58 | 70 | #include <linux/tick.h> |
f00b45c1 PZ |
71 | #include <linux/debugfs.h> |
72 | #include <linux/ctype.h> | |
6cd8a4bb | 73 | #include <linux/ftrace.h> |
1da177e4 | 74 | |
5517d86b | 75 | #include <asm/tlb.h> |
838225b4 | 76 | #include <asm/irq_regs.h> |
1da177e4 | 77 | |
6e0534f2 GH |
78 | #include "sched_cpupri.h" |
79 | ||
a8d154b0 | 80 | #define CREATE_TRACE_POINTS |
ad8d75ff | 81 | #include <trace/events/sched.h> |
a8d154b0 | 82 | |
1da177e4 LT |
83 | /* |
84 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
85 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
86 | * and back. | |
87 | */ | |
88 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
89 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
90 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
91 | ||
92 | /* | |
93 | * 'User priority' is the nice value converted to something we | |
94 | * can work with better when scaling various scheduler parameters, | |
95 | * it's a [ 0 ... 39 ] range. | |
96 | */ | |
97 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
98 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
99 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
100 | ||
101 | /* | |
d7876a08 | 102 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 103 | */ |
d6322faf | 104 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 105 | |
6aa645ea IM |
106 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
107 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
108 | ||
1da177e4 LT |
109 | /* |
110 | * These are the 'tuning knobs' of the scheduler: | |
111 | * | |
a4ec24b4 | 112 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
113 | * Timeslices get refilled after they expire. |
114 | */ | |
1da177e4 | 115 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 116 | |
d0b27fa7 PZ |
117 | /* |
118 | * single value that denotes runtime == period, ie unlimited time. | |
119 | */ | |
120 | #define RUNTIME_INF ((u64)~0ULL) | |
121 | ||
e05606d3 IM |
122 | static inline int rt_policy(int policy) |
123 | { | |
3f33a7ce | 124 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
125 | return 1; |
126 | return 0; | |
127 | } | |
128 | ||
129 | static inline int task_has_rt_policy(struct task_struct *p) | |
130 | { | |
131 | return rt_policy(p->policy); | |
132 | } | |
133 | ||
1da177e4 | 134 | /* |
6aa645ea | 135 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 136 | */ |
6aa645ea IM |
137 | struct rt_prio_array { |
138 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
139 | struct list_head queue[MAX_RT_PRIO]; | |
140 | }; | |
141 | ||
d0b27fa7 | 142 | struct rt_bandwidth { |
ea736ed5 IM |
143 | /* nests inside the rq lock: */ |
144 | spinlock_t rt_runtime_lock; | |
145 | ktime_t rt_period; | |
146 | u64 rt_runtime; | |
147 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
148 | }; |
149 | ||
150 | static struct rt_bandwidth def_rt_bandwidth; | |
151 | ||
152 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
153 | ||
154 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
155 | { | |
156 | struct rt_bandwidth *rt_b = | |
157 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
158 | ktime_t now; | |
159 | int overrun; | |
160 | int idle = 0; | |
161 | ||
162 | for (;;) { | |
163 | now = hrtimer_cb_get_time(timer); | |
164 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
165 | ||
166 | if (!overrun) | |
167 | break; | |
168 | ||
169 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
170 | } | |
171 | ||
172 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
173 | } | |
174 | ||
175 | static | |
176 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
177 | { | |
178 | rt_b->rt_period = ns_to_ktime(period); | |
179 | rt_b->rt_runtime = runtime; | |
180 | ||
ac086bc2 PZ |
181 | spin_lock_init(&rt_b->rt_runtime_lock); |
182 | ||
d0b27fa7 PZ |
183 | hrtimer_init(&rt_b->rt_period_timer, |
184 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
185 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
186 | } |
187 | ||
c8bfff6d KH |
188 | static inline int rt_bandwidth_enabled(void) |
189 | { | |
190 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
191 | } |
192 | ||
193 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
194 | { | |
195 | ktime_t now; | |
196 | ||
cac64d00 | 197 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
198 | return; |
199 | ||
200 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
201 | return; | |
202 | ||
203 | spin_lock(&rt_b->rt_runtime_lock); | |
204 | for (;;) { | |
7f1e2ca9 PZ |
205 | unsigned long delta; |
206 | ktime_t soft, hard; | |
207 | ||
d0b27fa7 PZ |
208 | if (hrtimer_active(&rt_b->rt_period_timer)) |
209 | break; | |
210 | ||
211 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
212 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
213 | |
214 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
215 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
216 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
217 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 218 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 PZ |
219 | } |
220 | spin_unlock(&rt_b->rt_runtime_lock); | |
221 | } | |
222 | ||
223 | #ifdef CONFIG_RT_GROUP_SCHED | |
224 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
225 | { | |
226 | hrtimer_cancel(&rt_b->rt_period_timer); | |
227 | } | |
228 | #endif | |
229 | ||
712555ee HC |
230 | /* |
231 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
232 | * detach_destroy_domains and partition_sched_domains. | |
233 | */ | |
234 | static DEFINE_MUTEX(sched_domains_mutex); | |
235 | ||
052f1dc7 | 236 | #ifdef CONFIG_GROUP_SCHED |
29f59db3 | 237 | |
68318b8e SV |
238 | #include <linux/cgroup.h> |
239 | ||
29f59db3 SV |
240 | struct cfs_rq; |
241 | ||
6f505b16 PZ |
242 | static LIST_HEAD(task_groups); |
243 | ||
29f59db3 | 244 | /* task group related information */ |
4cf86d77 | 245 | struct task_group { |
052f1dc7 | 246 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
247 | struct cgroup_subsys_state css; |
248 | #endif | |
052f1dc7 | 249 | |
6c415b92 AB |
250 | #ifdef CONFIG_USER_SCHED |
251 | uid_t uid; | |
252 | #endif | |
253 | ||
052f1dc7 | 254 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
255 | /* schedulable entities of this group on each cpu */ |
256 | struct sched_entity **se; | |
257 | /* runqueue "owned" by this group on each cpu */ | |
258 | struct cfs_rq **cfs_rq; | |
259 | unsigned long shares; | |
052f1dc7 PZ |
260 | #endif |
261 | ||
262 | #ifdef CONFIG_RT_GROUP_SCHED | |
263 | struct sched_rt_entity **rt_se; | |
264 | struct rt_rq **rt_rq; | |
265 | ||
d0b27fa7 | 266 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 267 | #endif |
6b2d7700 | 268 | |
ae8393e5 | 269 | struct rcu_head rcu; |
6f505b16 | 270 | struct list_head list; |
f473aa5e PZ |
271 | |
272 | struct task_group *parent; | |
273 | struct list_head siblings; | |
274 | struct list_head children; | |
29f59db3 SV |
275 | }; |
276 | ||
354d60c2 | 277 | #ifdef CONFIG_USER_SCHED |
eff766a6 | 278 | |
6c415b92 AB |
279 | /* Helper function to pass uid information to create_sched_user() */ |
280 | void set_tg_uid(struct user_struct *user) | |
281 | { | |
282 | user->tg->uid = user->uid; | |
283 | } | |
284 | ||
eff766a6 PZ |
285 | /* |
286 | * Root task group. | |
84e9dabf AS |
287 | * Every UID task group (including init_task_group aka UID-0) will |
288 | * be a child to this group. | |
eff766a6 PZ |
289 | */ |
290 | struct task_group root_task_group; | |
291 | ||
052f1dc7 | 292 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
293 | /* Default task group's sched entity on each cpu */ |
294 | static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); | |
295 | /* Default task group's cfs_rq on each cpu */ | |
84e9dabf | 296 | static DEFINE_PER_CPU(struct cfs_rq, init_tg_cfs_rq) ____cacheline_aligned_in_smp; |
6d6bc0ad | 297 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
298 | |
299 | #ifdef CONFIG_RT_GROUP_SCHED | |
300 | static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); | |
301 | static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 302 | #endif /* CONFIG_RT_GROUP_SCHED */ |
9a7e0b18 | 303 | #else /* !CONFIG_USER_SCHED */ |
eff766a6 | 304 | #define root_task_group init_task_group |
9a7e0b18 | 305 | #endif /* CONFIG_USER_SCHED */ |
6f505b16 | 306 | |
8ed36996 | 307 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
308 | * a task group's cpu shares. |
309 | */ | |
8ed36996 | 310 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 311 | |
57310a98 PZ |
312 | #ifdef CONFIG_SMP |
313 | static int root_task_group_empty(void) | |
314 | { | |
315 | return list_empty(&root_task_group.children); | |
316 | } | |
317 | #endif | |
318 | ||
052f1dc7 | 319 | #ifdef CONFIG_FAIR_GROUP_SCHED |
052f1dc7 PZ |
320 | #ifdef CONFIG_USER_SCHED |
321 | # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) | |
6d6bc0ad | 322 | #else /* !CONFIG_USER_SCHED */ |
052f1dc7 | 323 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
6d6bc0ad | 324 | #endif /* CONFIG_USER_SCHED */ |
052f1dc7 | 325 | |
cb4ad1ff | 326 | /* |
2e084786 LJ |
327 | * A weight of 0 or 1 can cause arithmetics problems. |
328 | * A weight of a cfs_rq is the sum of weights of which entities | |
329 | * are queued on this cfs_rq, so a weight of a entity should not be | |
330 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
331 | * (The default weight is 1024 - so there's no practical |
332 | * limitation from this.) | |
333 | */ | |
18d95a28 | 334 | #define MIN_SHARES 2 |
2e084786 | 335 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 336 | |
052f1dc7 PZ |
337 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
338 | #endif | |
339 | ||
29f59db3 | 340 | /* Default task group. |
3a252015 | 341 | * Every task in system belong to this group at bootup. |
29f59db3 | 342 | */ |
434d53b0 | 343 | struct task_group init_task_group; |
29f59db3 SV |
344 | |
345 | /* return group to which a task belongs */ | |
4cf86d77 | 346 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 347 | { |
4cf86d77 | 348 | struct task_group *tg; |
9b5b7751 | 349 | |
052f1dc7 | 350 | #ifdef CONFIG_USER_SCHED |
c69e8d9c DH |
351 | rcu_read_lock(); |
352 | tg = __task_cred(p)->user->tg; | |
353 | rcu_read_unlock(); | |
052f1dc7 | 354 | #elif defined(CONFIG_CGROUP_SCHED) |
68318b8e SV |
355 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
356 | struct task_group, css); | |
24e377a8 | 357 | #else |
41a2d6cf | 358 | tg = &init_task_group; |
24e377a8 | 359 | #endif |
9b5b7751 | 360 | return tg; |
29f59db3 SV |
361 | } |
362 | ||
363 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 364 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 365 | { |
052f1dc7 | 366 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
367 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
368 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 369 | #endif |
6f505b16 | 370 | |
052f1dc7 | 371 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
372 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
373 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 374 | #endif |
29f59db3 SV |
375 | } |
376 | ||
377 | #else | |
378 | ||
57310a98 PZ |
379 | #ifdef CONFIG_SMP |
380 | static int root_task_group_empty(void) | |
381 | { | |
382 | return 1; | |
383 | } | |
384 | #endif | |
385 | ||
6f505b16 | 386 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
387 | static inline struct task_group *task_group(struct task_struct *p) |
388 | { | |
389 | return NULL; | |
390 | } | |
29f59db3 | 391 | |
052f1dc7 | 392 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 393 | |
6aa645ea IM |
394 | /* CFS-related fields in a runqueue */ |
395 | struct cfs_rq { | |
396 | struct load_weight load; | |
397 | unsigned long nr_running; | |
398 | ||
6aa645ea | 399 | u64 exec_clock; |
e9acbff6 | 400 | u64 min_vruntime; |
6aa645ea IM |
401 | |
402 | struct rb_root tasks_timeline; | |
403 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
404 | |
405 | struct list_head tasks; | |
406 | struct list_head *balance_iterator; | |
407 | ||
408 | /* | |
409 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
410 | * It is set to NULL otherwise (i.e when none are currently running). |
411 | */ | |
4793241b | 412 | struct sched_entity *curr, *next, *last; |
ddc97297 | 413 | |
5ac5c4d6 | 414 | unsigned int nr_spread_over; |
ddc97297 | 415 | |
62160e3f | 416 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
417 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
418 | ||
41a2d6cf IM |
419 | /* |
420 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
421 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
422 | * (like users, containers etc.) | |
423 | * | |
424 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
425 | * list is used during load balance. | |
426 | */ | |
41a2d6cf IM |
427 | struct list_head leaf_cfs_rq_list; |
428 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
429 | |
430 | #ifdef CONFIG_SMP | |
c09595f6 | 431 | /* |
c8cba857 | 432 | * the part of load.weight contributed by tasks |
c09595f6 | 433 | */ |
c8cba857 | 434 | unsigned long task_weight; |
c09595f6 | 435 | |
c8cba857 PZ |
436 | /* |
437 | * h_load = weight * f(tg) | |
438 | * | |
439 | * Where f(tg) is the recursive weight fraction assigned to | |
440 | * this group. | |
441 | */ | |
442 | unsigned long h_load; | |
c09595f6 | 443 | |
c8cba857 PZ |
444 | /* |
445 | * this cpu's part of tg->shares | |
446 | */ | |
447 | unsigned long shares; | |
f1d239f7 PZ |
448 | |
449 | /* | |
450 | * load.weight at the time we set shares | |
451 | */ | |
452 | unsigned long rq_weight; | |
c09595f6 | 453 | #endif |
6aa645ea IM |
454 | #endif |
455 | }; | |
1da177e4 | 456 | |
6aa645ea IM |
457 | /* Real-Time classes' related field in a runqueue: */ |
458 | struct rt_rq { | |
459 | struct rt_prio_array active; | |
63489e45 | 460 | unsigned long rt_nr_running; |
052f1dc7 | 461 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
462 | struct { |
463 | int curr; /* highest queued rt task prio */ | |
398a153b | 464 | #ifdef CONFIG_SMP |
e864c499 | 465 | int next; /* next highest */ |
398a153b | 466 | #endif |
e864c499 | 467 | } highest_prio; |
6f505b16 | 468 | #endif |
fa85ae24 | 469 | #ifdef CONFIG_SMP |
73fe6aae | 470 | unsigned long rt_nr_migratory; |
a1ba4d8b | 471 | unsigned long rt_nr_total; |
a22d7fc1 | 472 | int overloaded; |
917b627d | 473 | struct plist_head pushable_tasks; |
fa85ae24 | 474 | #endif |
6f505b16 | 475 | int rt_throttled; |
fa85ae24 | 476 | u64 rt_time; |
ac086bc2 | 477 | u64 rt_runtime; |
ea736ed5 | 478 | /* Nests inside the rq lock: */ |
ac086bc2 | 479 | spinlock_t rt_runtime_lock; |
6f505b16 | 480 | |
052f1dc7 | 481 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
482 | unsigned long rt_nr_boosted; |
483 | ||
6f505b16 PZ |
484 | struct rq *rq; |
485 | struct list_head leaf_rt_rq_list; | |
486 | struct task_group *tg; | |
487 | struct sched_rt_entity *rt_se; | |
488 | #endif | |
6aa645ea IM |
489 | }; |
490 | ||
57d885fe GH |
491 | #ifdef CONFIG_SMP |
492 | ||
493 | /* | |
494 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
495 | * variables. Each exclusive cpuset essentially defines an island domain by |
496 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
497 | * exclusive cpuset is created, we also create and attach a new root-domain |
498 | * object. | |
499 | * | |
57d885fe GH |
500 | */ |
501 | struct root_domain { | |
502 | atomic_t refcount; | |
c6c4927b RR |
503 | cpumask_var_t span; |
504 | cpumask_var_t online; | |
637f5085 | 505 | |
0eab9146 | 506 | /* |
637f5085 GH |
507 | * The "RT overload" flag: it gets set if a CPU has more than |
508 | * one runnable RT task. | |
509 | */ | |
c6c4927b | 510 | cpumask_var_t rto_mask; |
0eab9146 | 511 | atomic_t rto_count; |
6e0534f2 GH |
512 | #ifdef CONFIG_SMP |
513 | struct cpupri cpupri; | |
514 | #endif | |
7a09b1a2 VS |
515 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
516 | /* | |
517 | * Preferred wake up cpu nominated by sched_mc balance that will be | |
518 | * used when most cpus are idle in the system indicating overall very | |
519 | * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) | |
520 | */ | |
521 | unsigned int sched_mc_preferred_wakeup_cpu; | |
522 | #endif | |
57d885fe GH |
523 | }; |
524 | ||
dc938520 GH |
525 | /* |
526 | * By default the system creates a single root-domain with all cpus as | |
527 | * members (mimicking the global state we have today). | |
528 | */ | |
57d885fe GH |
529 | static struct root_domain def_root_domain; |
530 | ||
531 | #endif | |
532 | ||
1da177e4 LT |
533 | /* |
534 | * This is the main, per-CPU runqueue data structure. | |
535 | * | |
536 | * Locking rule: those places that want to lock multiple runqueues | |
537 | * (such as the load balancing or the thread migration code), lock | |
538 | * acquire operations must be ordered by ascending &runqueue. | |
539 | */ | |
70b97a7f | 540 | struct rq { |
d8016491 IM |
541 | /* runqueue lock: */ |
542 | spinlock_t lock; | |
1da177e4 LT |
543 | |
544 | /* | |
545 | * nr_running and cpu_load should be in the same cacheline because | |
546 | * remote CPUs use both these fields when doing load calculation. | |
547 | */ | |
548 | unsigned long nr_running; | |
6aa645ea IM |
549 | #define CPU_LOAD_IDX_MAX 5 |
550 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
46cb4b7c | 551 | #ifdef CONFIG_NO_HZ |
15934a37 | 552 | unsigned long last_tick_seen; |
46cb4b7c SS |
553 | unsigned char in_nohz_recently; |
554 | #endif | |
d8016491 IM |
555 | /* capture load from *all* tasks on this cpu: */ |
556 | struct load_weight load; | |
6aa645ea IM |
557 | unsigned long nr_load_updates; |
558 | u64 nr_switches; | |
23a185ca | 559 | u64 nr_migrations_in; |
6aa645ea IM |
560 | |
561 | struct cfs_rq cfs; | |
6f505b16 | 562 | struct rt_rq rt; |
6f505b16 | 563 | |
6aa645ea | 564 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
565 | /* list of leaf cfs_rq on this cpu: */ |
566 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
567 | #endif |
568 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 569 | struct list_head leaf_rt_rq_list; |
1da177e4 | 570 | #endif |
1da177e4 LT |
571 | |
572 | /* | |
573 | * This is part of a global counter where only the total sum | |
574 | * over all CPUs matters. A task can increase this counter on | |
575 | * one CPU and if it got migrated afterwards it may decrease | |
576 | * it on another CPU. Always updated under the runqueue lock: | |
577 | */ | |
578 | unsigned long nr_uninterruptible; | |
579 | ||
36c8b586 | 580 | struct task_struct *curr, *idle; |
c9819f45 | 581 | unsigned long next_balance; |
1da177e4 | 582 | struct mm_struct *prev_mm; |
6aa645ea | 583 | |
3e51f33f | 584 | u64 clock; |
6aa645ea | 585 | |
1da177e4 LT |
586 | atomic_t nr_iowait; |
587 | ||
588 | #ifdef CONFIG_SMP | |
0eab9146 | 589 | struct root_domain *rd; |
1da177e4 LT |
590 | struct sched_domain *sd; |
591 | ||
a0a522ce | 592 | unsigned char idle_at_tick; |
1da177e4 | 593 | /* For active balancing */ |
3f029d3c | 594 | int post_schedule; |
1da177e4 LT |
595 | int active_balance; |
596 | int push_cpu; | |
d8016491 IM |
597 | /* cpu of this runqueue: */ |
598 | int cpu; | |
1f11eb6a | 599 | int online; |
1da177e4 | 600 | |
a8a51d5e | 601 | unsigned long avg_load_per_task; |
1da177e4 | 602 | |
36c8b586 | 603 | struct task_struct *migration_thread; |
1da177e4 | 604 | struct list_head migration_queue; |
e9e9250b PZ |
605 | |
606 | u64 rt_avg; | |
607 | u64 age_stamp; | |
1da177e4 LT |
608 | #endif |
609 | ||
dce48a84 TG |
610 | /* calc_load related fields */ |
611 | unsigned long calc_load_update; | |
612 | long calc_load_active; | |
613 | ||
8f4d37ec | 614 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
615 | #ifdef CONFIG_SMP |
616 | int hrtick_csd_pending; | |
617 | struct call_single_data hrtick_csd; | |
618 | #endif | |
8f4d37ec PZ |
619 | struct hrtimer hrtick_timer; |
620 | #endif | |
621 | ||
1da177e4 LT |
622 | #ifdef CONFIG_SCHEDSTATS |
623 | /* latency stats */ | |
624 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
625 | unsigned long long rq_cpu_time; |
626 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
627 | |
628 | /* sys_sched_yield() stats */ | |
480b9434 | 629 | unsigned int yld_count; |
1da177e4 LT |
630 | |
631 | /* schedule() stats */ | |
480b9434 KC |
632 | unsigned int sched_switch; |
633 | unsigned int sched_count; | |
634 | unsigned int sched_goidle; | |
1da177e4 LT |
635 | |
636 | /* try_to_wake_up() stats */ | |
480b9434 KC |
637 | unsigned int ttwu_count; |
638 | unsigned int ttwu_local; | |
b8efb561 IM |
639 | |
640 | /* BKL stats */ | |
480b9434 | 641 | unsigned int bkl_count; |
1da177e4 LT |
642 | #endif |
643 | }; | |
644 | ||
f34e3b61 | 645 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 646 | |
15afe09b | 647 | static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) |
dd41f596 | 648 | { |
15afe09b | 649 | rq->curr->sched_class->check_preempt_curr(rq, p, sync); |
dd41f596 IM |
650 | } |
651 | ||
0a2966b4 CL |
652 | static inline int cpu_of(struct rq *rq) |
653 | { | |
654 | #ifdef CONFIG_SMP | |
655 | return rq->cpu; | |
656 | #else | |
657 | return 0; | |
658 | #endif | |
659 | } | |
660 | ||
674311d5 NP |
661 | /* |
662 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 663 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
664 | * |
665 | * The domain tree of any CPU may only be accessed from within | |
666 | * preempt-disabled sections. | |
667 | */ | |
48f24c4d IM |
668 | #define for_each_domain(cpu, __sd) \ |
669 | for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) | |
1da177e4 LT |
670 | |
671 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
672 | #define this_rq() (&__get_cpu_var(runqueues)) | |
673 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
674 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 675 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 676 | |
aa9c4c0f | 677 | inline void update_rq_clock(struct rq *rq) |
3e51f33f PZ |
678 | { |
679 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
680 | } | |
681 | ||
bf5c91ba IM |
682 | /* |
683 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
684 | */ | |
685 | #ifdef CONFIG_SCHED_DEBUG | |
686 | # define const_debug __read_mostly | |
687 | #else | |
688 | # define const_debug static const | |
689 | #endif | |
690 | ||
017730c1 IM |
691 | /** |
692 | * runqueue_is_locked | |
693 | * | |
694 | * Returns true if the current cpu runqueue is locked. | |
695 | * This interface allows printk to be called with the runqueue lock | |
696 | * held and know whether or not it is OK to wake up the klogd. | |
697 | */ | |
698 | int runqueue_is_locked(void) | |
699 | { | |
700 | int cpu = get_cpu(); | |
701 | struct rq *rq = cpu_rq(cpu); | |
702 | int ret; | |
703 | ||
704 | ret = spin_is_locked(&rq->lock); | |
705 | put_cpu(); | |
706 | return ret; | |
707 | } | |
708 | ||
bf5c91ba IM |
709 | /* |
710 | * Debugging: various feature bits | |
711 | */ | |
f00b45c1 PZ |
712 | |
713 | #define SCHED_FEAT(name, enabled) \ | |
714 | __SCHED_FEAT_##name , | |
715 | ||
bf5c91ba | 716 | enum { |
f00b45c1 | 717 | #include "sched_features.h" |
bf5c91ba IM |
718 | }; |
719 | ||
f00b45c1 PZ |
720 | #undef SCHED_FEAT |
721 | ||
722 | #define SCHED_FEAT(name, enabled) \ | |
723 | (1UL << __SCHED_FEAT_##name) * enabled | | |
724 | ||
bf5c91ba | 725 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
726 | #include "sched_features.h" |
727 | 0; | |
728 | ||
729 | #undef SCHED_FEAT | |
730 | ||
731 | #ifdef CONFIG_SCHED_DEBUG | |
732 | #define SCHED_FEAT(name, enabled) \ | |
733 | #name , | |
734 | ||
983ed7a6 | 735 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
736 | #include "sched_features.h" |
737 | NULL | |
738 | }; | |
739 | ||
740 | #undef SCHED_FEAT | |
741 | ||
34f3a814 | 742 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 743 | { |
f00b45c1 PZ |
744 | int i; |
745 | ||
746 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
747 | if (!(sysctl_sched_features & (1UL << i))) |
748 | seq_puts(m, "NO_"); | |
749 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 750 | } |
34f3a814 | 751 | seq_puts(m, "\n"); |
f00b45c1 | 752 | |
34f3a814 | 753 | return 0; |
f00b45c1 PZ |
754 | } |
755 | ||
756 | static ssize_t | |
757 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
758 | size_t cnt, loff_t *ppos) | |
759 | { | |
760 | char buf[64]; | |
761 | char *cmp = buf; | |
762 | int neg = 0; | |
763 | int i; | |
764 | ||
765 | if (cnt > 63) | |
766 | cnt = 63; | |
767 | ||
768 | if (copy_from_user(&buf, ubuf, cnt)) | |
769 | return -EFAULT; | |
770 | ||
771 | buf[cnt] = 0; | |
772 | ||
c24b7c52 | 773 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
774 | neg = 1; |
775 | cmp += 3; | |
776 | } | |
777 | ||
778 | for (i = 0; sched_feat_names[i]; i++) { | |
779 | int len = strlen(sched_feat_names[i]); | |
780 | ||
781 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
782 | if (neg) | |
783 | sysctl_sched_features &= ~(1UL << i); | |
784 | else | |
785 | sysctl_sched_features |= (1UL << i); | |
786 | break; | |
787 | } | |
788 | } | |
789 | ||
790 | if (!sched_feat_names[i]) | |
791 | return -EINVAL; | |
792 | ||
793 | filp->f_pos += cnt; | |
794 | ||
795 | return cnt; | |
796 | } | |
797 | ||
34f3a814 LZ |
798 | static int sched_feat_open(struct inode *inode, struct file *filp) |
799 | { | |
800 | return single_open(filp, sched_feat_show, NULL); | |
801 | } | |
802 | ||
f00b45c1 | 803 | static struct file_operations sched_feat_fops = { |
34f3a814 LZ |
804 | .open = sched_feat_open, |
805 | .write = sched_feat_write, | |
806 | .read = seq_read, | |
807 | .llseek = seq_lseek, | |
808 | .release = single_release, | |
f00b45c1 PZ |
809 | }; |
810 | ||
811 | static __init int sched_init_debug(void) | |
812 | { | |
f00b45c1 PZ |
813 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
814 | &sched_feat_fops); | |
815 | ||
816 | return 0; | |
817 | } | |
818 | late_initcall(sched_init_debug); | |
819 | ||
820 | #endif | |
821 | ||
822 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 823 | |
b82d9fdd PZ |
824 | /* |
825 | * Number of tasks to iterate in a single balance run. | |
826 | * Limited because this is done with IRQs disabled. | |
827 | */ | |
828 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
829 | ||
2398f2c6 PZ |
830 | /* |
831 | * ratelimit for updating the group shares. | |
55cd5340 | 832 | * default: 0.25ms |
2398f2c6 | 833 | */ |
55cd5340 | 834 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 835 | |
ffda12a1 PZ |
836 | /* |
837 | * Inject some fuzzyness into changing the per-cpu group shares | |
838 | * this avoids remote rq-locks at the expense of fairness. | |
839 | * default: 4 | |
840 | */ | |
841 | unsigned int sysctl_sched_shares_thresh = 4; | |
842 | ||
e9e9250b PZ |
843 | /* |
844 | * period over which we average the RT time consumption, measured | |
845 | * in ms. | |
846 | * | |
847 | * default: 1s | |
848 | */ | |
849 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
850 | ||
fa85ae24 | 851 | /* |
9f0c1e56 | 852 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
853 | * default: 1s |
854 | */ | |
9f0c1e56 | 855 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 856 | |
6892b75e IM |
857 | static __read_mostly int scheduler_running; |
858 | ||
9f0c1e56 PZ |
859 | /* |
860 | * part of the period that we allow rt tasks to run in us. | |
861 | * default: 0.95s | |
862 | */ | |
863 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 864 | |
d0b27fa7 PZ |
865 | static inline u64 global_rt_period(void) |
866 | { | |
867 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
868 | } | |
869 | ||
870 | static inline u64 global_rt_runtime(void) | |
871 | { | |
e26873bb | 872 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
873 | return RUNTIME_INF; |
874 | ||
875 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
876 | } | |
fa85ae24 | 877 | |
1da177e4 | 878 | #ifndef prepare_arch_switch |
4866cde0 NP |
879 | # define prepare_arch_switch(next) do { } while (0) |
880 | #endif | |
881 | #ifndef finish_arch_switch | |
882 | # define finish_arch_switch(prev) do { } while (0) | |
883 | #endif | |
884 | ||
051a1d1a DA |
885 | static inline int task_current(struct rq *rq, struct task_struct *p) |
886 | { | |
887 | return rq->curr == p; | |
888 | } | |
889 | ||
4866cde0 | 890 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 891 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 892 | { |
051a1d1a | 893 | return task_current(rq, p); |
4866cde0 NP |
894 | } |
895 | ||
70b97a7f | 896 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
897 | { |
898 | } | |
899 | ||
70b97a7f | 900 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 901 | { |
da04c035 IM |
902 | #ifdef CONFIG_DEBUG_SPINLOCK |
903 | /* this is a valid case when another task releases the spinlock */ | |
904 | rq->lock.owner = current; | |
905 | #endif | |
8a25d5de IM |
906 | /* |
907 | * If we are tracking spinlock dependencies then we have to | |
908 | * fix up the runqueue lock - which gets 'carried over' from | |
909 | * prev into current: | |
910 | */ | |
911 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
912 | ||
4866cde0 NP |
913 | spin_unlock_irq(&rq->lock); |
914 | } | |
915 | ||
916 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 917 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
918 | { |
919 | #ifdef CONFIG_SMP | |
920 | return p->oncpu; | |
921 | #else | |
051a1d1a | 922 | return task_current(rq, p); |
4866cde0 NP |
923 | #endif |
924 | } | |
925 | ||
70b97a7f | 926 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
927 | { |
928 | #ifdef CONFIG_SMP | |
929 | /* | |
930 | * We can optimise this out completely for !SMP, because the | |
931 | * SMP rebalancing from interrupt is the only thing that cares | |
932 | * here. | |
933 | */ | |
934 | next->oncpu = 1; | |
935 | #endif | |
936 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
937 | spin_unlock_irq(&rq->lock); | |
938 | #else | |
939 | spin_unlock(&rq->lock); | |
940 | #endif | |
941 | } | |
942 | ||
70b97a7f | 943 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
944 | { |
945 | #ifdef CONFIG_SMP | |
946 | /* | |
947 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
948 | * We must ensure this doesn't happen until the switch is completely | |
949 | * finished. | |
950 | */ | |
951 | smp_wmb(); | |
952 | prev->oncpu = 0; | |
953 | #endif | |
954 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
955 | local_irq_enable(); | |
1da177e4 | 956 | #endif |
4866cde0 NP |
957 | } |
958 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 959 | |
b29739f9 IM |
960 | /* |
961 | * __task_rq_lock - lock the runqueue a given task resides on. | |
962 | * Must be called interrupts disabled. | |
963 | */ | |
70b97a7f | 964 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
965 | __acquires(rq->lock) |
966 | { | |
3a5c359a AK |
967 | for (;;) { |
968 | struct rq *rq = task_rq(p); | |
969 | spin_lock(&rq->lock); | |
970 | if (likely(rq == task_rq(p))) | |
971 | return rq; | |
b29739f9 | 972 | spin_unlock(&rq->lock); |
b29739f9 | 973 | } |
b29739f9 IM |
974 | } |
975 | ||
1da177e4 LT |
976 | /* |
977 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 978 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
979 | * explicitly disabling preemption. |
980 | */ | |
70b97a7f | 981 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
982 | __acquires(rq->lock) |
983 | { | |
70b97a7f | 984 | struct rq *rq; |
1da177e4 | 985 | |
3a5c359a AK |
986 | for (;;) { |
987 | local_irq_save(*flags); | |
988 | rq = task_rq(p); | |
989 | spin_lock(&rq->lock); | |
990 | if (likely(rq == task_rq(p))) | |
991 | return rq; | |
1da177e4 | 992 | spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 993 | } |
1da177e4 LT |
994 | } |
995 | ||
ad474cac ON |
996 | void task_rq_unlock_wait(struct task_struct *p) |
997 | { | |
998 | struct rq *rq = task_rq(p); | |
999 | ||
1000 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
1001 | spin_unlock_wait(&rq->lock); | |
1002 | } | |
1003 | ||
a9957449 | 1004 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
1005 | __releases(rq->lock) |
1006 | { | |
1007 | spin_unlock(&rq->lock); | |
1008 | } | |
1009 | ||
70b97a7f | 1010 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
1011 | __releases(rq->lock) |
1012 | { | |
1013 | spin_unlock_irqrestore(&rq->lock, *flags); | |
1014 | } | |
1015 | ||
1da177e4 | 1016 | /* |
cc2a73b5 | 1017 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1018 | */ |
a9957449 | 1019 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1020 | __acquires(rq->lock) |
1021 | { | |
70b97a7f | 1022 | struct rq *rq; |
1da177e4 LT |
1023 | |
1024 | local_irq_disable(); | |
1025 | rq = this_rq(); | |
1026 | spin_lock(&rq->lock); | |
1027 | ||
1028 | return rq; | |
1029 | } | |
1030 | ||
8f4d37ec PZ |
1031 | #ifdef CONFIG_SCHED_HRTICK |
1032 | /* | |
1033 | * Use HR-timers to deliver accurate preemption points. | |
1034 | * | |
1035 | * Its all a bit involved since we cannot program an hrt while holding the | |
1036 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1037 | * reschedule event. | |
1038 | * | |
1039 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1040 | * rq->lock. | |
1041 | */ | |
8f4d37ec PZ |
1042 | |
1043 | /* | |
1044 | * Use hrtick when: | |
1045 | * - enabled by features | |
1046 | * - hrtimer is actually high res | |
1047 | */ | |
1048 | static inline int hrtick_enabled(struct rq *rq) | |
1049 | { | |
1050 | if (!sched_feat(HRTICK)) | |
1051 | return 0; | |
ba42059f | 1052 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1053 | return 0; |
8f4d37ec PZ |
1054 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1055 | } | |
1056 | ||
8f4d37ec PZ |
1057 | static void hrtick_clear(struct rq *rq) |
1058 | { | |
1059 | if (hrtimer_active(&rq->hrtick_timer)) | |
1060 | hrtimer_cancel(&rq->hrtick_timer); | |
1061 | } | |
1062 | ||
8f4d37ec PZ |
1063 | /* |
1064 | * High-resolution timer tick. | |
1065 | * Runs from hardirq context with interrupts disabled. | |
1066 | */ | |
1067 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1068 | { | |
1069 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1070 | ||
1071 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1072 | ||
1073 | spin_lock(&rq->lock); | |
3e51f33f | 1074 | update_rq_clock(rq); |
8f4d37ec PZ |
1075 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
1076 | spin_unlock(&rq->lock); | |
1077 | ||
1078 | return HRTIMER_NORESTART; | |
1079 | } | |
1080 | ||
95e904c7 | 1081 | #ifdef CONFIG_SMP |
31656519 PZ |
1082 | /* |
1083 | * called from hardirq (IPI) context | |
1084 | */ | |
1085 | static void __hrtick_start(void *arg) | |
b328ca18 | 1086 | { |
31656519 | 1087 | struct rq *rq = arg; |
b328ca18 | 1088 | |
31656519 PZ |
1089 | spin_lock(&rq->lock); |
1090 | hrtimer_restart(&rq->hrtick_timer); | |
1091 | rq->hrtick_csd_pending = 0; | |
1092 | spin_unlock(&rq->lock); | |
b328ca18 PZ |
1093 | } |
1094 | ||
31656519 PZ |
1095 | /* |
1096 | * Called to set the hrtick timer state. | |
1097 | * | |
1098 | * called with rq->lock held and irqs disabled | |
1099 | */ | |
1100 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1101 | { |
31656519 PZ |
1102 | struct hrtimer *timer = &rq->hrtick_timer; |
1103 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1104 | |
cc584b21 | 1105 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1106 | |
1107 | if (rq == this_rq()) { | |
1108 | hrtimer_restart(timer); | |
1109 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1110 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1111 | rq->hrtick_csd_pending = 1; |
1112 | } | |
b328ca18 PZ |
1113 | } |
1114 | ||
1115 | static int | |
1116 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1117 | { | |
1118 | int cpu = (int)(long)hcpu; | |
1119 | ||
1120 | switch (action) { | |
1121 | case CPU_UP_CANCELED: | |
1122 | case CPU_UP_CANCELED_FROZEN: | |
1123 | case CPU_DOWN_PREPARE: | |
1124 | case CPU_DOWN_PREPARE_FROZEN: | |
1125 | case CPU_DEAD: | |
1126 | case CPU_DEAD_FROZEN: | |
31656519 | 1127 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1128 | return NOTIFY_OK; |
1129 | } | |
1130 | ||
1131 | return NOTIFY_DONE; | |
1132 | } | |
1133 | ||
fa748203 | 1134 | static __init void init_hrtick(void) |
b328ca18 PZ |
1135 | { |
1136 | hotcpu_notifier(hotplug_hrtick, 0); | |
1137 | } | |
31656519 PZ |
1138 | #else |
1139 | /* | |
1140 | * Called to set the hrtick timer state. | |
1141 | * | |
1142 | * called with rq->lock held and irqs disabled | |
1143 | */ | |
1144 | static void hrtick_start(struct rq *rq, u64 delay) | |
1145 | { | |
7f1e2ca9 | 1146 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1147 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1148 | } |
b328ca18 | 1149 | |
006c75f1 | 1150 | static inline void init_hrtick(void) |
8f4d37ec | 1151 | { |
8f4d37ec | 1152 | } |
31656519 | 1153 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1154 | |
31656519 | 1155 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1156 | { |
31656519 PZ |
1157 | #ifdef CONFIG_SMP |
1158 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1159 | |
31656519 PZ |
1160 | rq->hrtick_csd.flags = 0; |
1161 | rq->hrtick_csd.func = __hrtick_start; | |
1162 | rq->hrtick_csd.info = rq; | |
1163 | #endif | |
8f4d37ec | 1164 | |
31656519 PZ |
1165 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1166 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1167 | } |
006c75f1 | 1168 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1169 | static inline void hrtick_clear(struct rq *rq) |
1170 | { | |
1171 | } | |
1172 | ||
8f4d37ec PZ |
1173 | static inline void init_rq_hrtick(struct rq *rq) |
1174 | { | |
1175 | } | |
1176 | ||
b328ca18 PZ |
1177 | static inline void init_hrtick(void) |
1178 | { | |
1179 | } | |
006c75f1 | 1180 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1181 | |
c24d20db IM |
1182 | /* |
1183 | * resched_task - mark a task 'to be rescheduled now'. | |
1184 | * | |
1185 | * On UP this means the setting of the need_resched flag, on SMP it | |
1186 | * might also involve a cross-CPU call to trigger the scheduler on | |
1187 | * the target CPU. | |
1188 | */ | |
1189 | #ifdef CONFIG_SMP | |
1190 | ||
1191 | #ifndef tsk_is_polling | |
1192 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1193 | #endif | |
1194 | ||
31656519 | 1195 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1196 | { |
1197 | int cpu; | |
1198 | ||
1199 | assert_spin_locked(&task_rq(p)->lock); | |
1200 | ||
5ed0cec0 | 1201 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1202 | return; |
1203 | ||
5ed0cec0 | 1204 | set_tsk_need_resched(p); |
c24d20db IM |
1205 | |
1206 | cpu = task_cpu(p); | |
1207 | if (cpu == smp_processor_id()) | |
1208 | return; | |
1209 | ||
1210 | /* NEED_RESCHED must be visible before we test polling */ | |
1211 | smp_mb(); | |
1212 | if (!tsk_is_polling(p)) | |
1213 | smp_send_reschedule(cpu); | |
1214 | } | |
1215 | ||
1216 | static void resched_cpu(int cpu) | |
1217 | { | |
1218 | struct rq *rq = cpu_rq(cpu); | |
1219 | unsigned long flags; | |
1220 | ||
1221 | if (!spin_trylock_irqsave(&rq->lock, flags)) | |
1222 | return; | |
1223 | resched_task(cpu_curr(cpu)); | |
1224 | spin_unlock_irqrestore(&rq->lock, flags); | |
1225 | } | |
06d8308c TG |
1226 | |
1227 | #ifdef CONFIG_NO_HZ | |
1228 | /* | |
1229 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1230 | * idle CPU then this timer might expire before the next timer event | |
1231 | * which is scheduled to wake up that CPU. In case of a completely | |
1232 | * idle system the next event might even be infinite time into the | |
1233 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1234 | * leaves the inner idle loop so the newly added timer is taken into | |
1235 | * account when the CPU goes back to idle and evaluates the timer | |
1236 | * wheel for the next timer event. | |
1237 | */ | |
1238 | void wake_up_idle_cpu(int cpu) | |
1239 | { | |
1240 | struct rq *rq = cpu_rq(cpu); | |
1241 | ||
1242 | if (cpu == smp_processor_id()) | |
1243 | return; | |
1244 | ||
1245 | /* | |
1246 | * This is safe, as this function is called with the timer | |
1247 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1248 | * to idle and has not yet set rq->curr to idle then it will | |
1249 | * be serialized on the timer wheel base lock and take the new | |
1250 | * timer into account automatically. | |
1251 | */ | |
1252 | if (rq->curr != rq->idle) | |
1253 | return; | |
1254 | ||
1255 | /* | |
1256 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1257 | * lockless. The worst case is that the other CPU runs the | |
1258 | * idle task through an additional NOOP schedule() | |
1259 | */ | |
5ed0cec0 | 1260 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1261 | |
1262 | /* NEED_RESCHED must be visible before we test polling */ | |
1263 | smp_mb(); | |
1264 | if (!tsk_is_polling(rq->idle)) | |
1265 | smp_send_reschedule(cpu); | |
1266 | } | |
6d6bc0ad | 1267 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1268 | |
e9e9250b PZ |
1269 | static u64 sched_avg_period(void) |
1270 | { | |
1271 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1272 | } | |
1273 | ||
1274 | static void sched_avg_update(struct rq *rq) | |
1275 | { | |
1276 | s64 period = sched_avg_period(); | |
1277 | ||
1278 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
1279 | rq->age_stamp += period; | |
1280 | rq->rt_avg /= 2; | |
1281 | } | |
1282 | } | |
1283 | ||
1284 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1285 | { | |
1286 | rq->rt_avg += rt_delta; | |
1287 | sched_avg_update(rq); | |
1288 | } | |
1289 | ||
6d6bc0ad | 1290 | #else /* !CONFIG_SMP */ |
31656519 | 1291 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1292 | { |
1293 | assert_spin_locked(&task_rq(p)->lock); | |
31656519 | 1294 | set_tsk_need_resched(p); |
c24d20db | 1295 | } |
e9e9250b PZ |
1296 | |
1297 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1298 | { | |
1299 | } | |
6d6bc0ad | 1300 | #endif /* CONFIG_SMP */ |
c24d20db | 1301 | |
45bf76df IM |
1302 | #if BITS_PER_LONG == 32 |
1303 | # define WMULT_CONST (~0UL) | |
1304 | #else | |
1305 | # define WMULT_CONST (1UL << 32) | |
1306 | #endif | |
1307 | ||
1308 | #define WMULT_SHIFT 32 | |
1309 | ||
194081eb IM |
1310 | /* |
1311 | * Shift right and round: | |
1312 | */ | |
cf2ab469 | 1313 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1314 | |
a7be37ac PZ |
1315 | /* |
1316 | * delta *= weight / lw | |
1317 | */ | |
cb1c4fc9 | 1318 | static unsigned long |
45bf76df IM |
1319 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1320 | struct load_weight *lw) | |
1321 | { | |
1322 | u64 tmp; | |
1323 | ||
7a232e03 LJ |
1324 | if (!lw->inv_weight) { |
1325 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1326 | lw->inv_weight = 1; | |
1327 | else | |
1328 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1329 | / (lw->weight+1); | |
1330 | } | |
45bf76df IM |
1331 | |
1332 | tmp = (u64)delta_exec * weight; | |
1333 | /* | |
1334 | * Check whether we'd overflow the 64-bit multiplication: | |
1335 | */ | |
194081eb | 1336 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1337 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1338 | WMULT_SHIFT/2); |
1339 | else | |
cf2ab469 | 1340 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1341 | |
ecf691da | 1342 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1343 | } |
1344 | ||
1091985b | 1345 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1346 | { |
1347 | lw->weight += inc; | |
e89996ae | 1348 | lw->inv_weight = 0; |
45bf76df IM |
1349 | } |
1350 | ||
1091985b | 1351 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1352 | { |
1353 | lw->weight -= dec; | |
e89996ae | 1354 | lw->inv_weight = 0; |
45bf76df IM |
1355 | } |
1356 | ||
2dd73a4f PW |
1357 | /* |
1358 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1359 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1360 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1361 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1362 | * scaled version of the new time slice allocation that they receive on time |
1363 | * slice expiry etc. | |
1364 | */ | |
1365 | ||
cce7ade8 PZ |
1366 | #define WEIGHT_IDLEPRIO 3 |
1367 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1368 | |
1369 | /* | |
1370 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1371 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1372 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1373 | * that remained on nice 0. | |
1374 | * | |
1375 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1376 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1377 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1378 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1379 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1380 | */ |
1381 | static const int prio_to_weight[40] = { | |
254753dc IM |
1382 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1383 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1384 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1385 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1386 | /* 0 */ 1024, 820, 655, 526, 423, | |
1387 | /* 5 */ 335, 272, 215, 172, 137, | |
1388 | /* 10 */ 110, 87, 70, 56, 45, | |
1389 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1390 | }; |
1391 | ||
5714d2de IM |
1392 | /* |
1393 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1394 | * | |
1395 | * In cases where the weight does not change often, we can use the | |
1396 | * precalculated inverse to speed up arithmetics by turning divisions | |
1397 | * into multiplications: | |
1398 | */ | |
dd41f596 | 1399 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1400 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1401 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1402 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1403 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1404 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1405 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1406 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1407 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1408 | }; |
2dd73a4f | 1409 | |
dd41f596 IM |
1410 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); |
1411 | ||
1412 | /* | |
1413 | * runqueue iterator, to support SMP load-balancing between different | |
1414 | * scheduling classes, without having to expose their internal data | |
1415 | * structures to the load-balancing proper: | |
1416 | */ | |
1417 | struct rq_iterator { | |
1418 | void *arg; | |
1419 | struct task_struct *(*start)(void *); | |
1420 | struct task_struct *(*next)(void *); | |
1421 | }; | |
1422 | ||
e1d1484f PW |
1423 | #ifdef CONFIG_SMP |
1424 | static unsigned long | |
1425 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1426 | unsigned long max_load_move, struct sched_domain *sd, | |
1427 | enum cpu_idle_type idle, int *all_pinned, | |
1428 | int *this_best_prio, struct rq_iterator *iterator); | |
1429 | ||
1430 | static int | |
1431 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1432 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1433 | struct rq_iterator *iterator); | |
e1d1484f | 1434 | #endif |
dd41f596 | 1435 | |
ef12fefa BR |
1436 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1437 | enum cpuacct_stat_index { | |
1438 | CPUACCT_STAT_USER, /* ... user mode */ | |
1439 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1440 | ||
1441 | CPUACCT_STAT_NSTATS, | |
1442 | }; | |
1443 | ||
d842de87 SV |
1444 | #ifdef CONFIG_CGROUP_CPUACCT |
1445 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1446 | static void cpuacct_update_stats(struct task_struct *tsk, |
1447 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1448 | #else |
1449 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1450 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1451 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1452 | #endif |
1453 | ||
18d95a28 PZ |
1454 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1455 | { | |
1456 | update_load_add(&rq->load, load); | |
1457 | } | |
1458 | ||
1459 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1460 | { | |
1461 | update_load_sub(&rq->load, load); | |
1462 | } | |
1463 | ||
7940ca36 | 1464 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1465 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1466 | |
1467 | /* | |
1468 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1469 | * leaving it for the final time. | |
1470 | */ | |
eb755805 | 1471 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1472 | { |
1473 | struct task_group *parent, *child; | |
eb755805 | 1474 | int ret; |
c09595f6 PZ |
1475 | |
1476 | rcu_read_lock(); | |
1477 | parent = &root_task_group; | |
1478 | down: | |
eb755805 PZ |
1479 | ret = (*down)(parent, data); |
1480 | if (ret) | |
1481 | goto out_unlock; | |
c09595f6 PZ |
1482 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1483 | parent = child; | |
1484 | goto down; | |
1485 | ||
1486 | up: | |
1487 | continue; | |
1488 | } | |
eb755805 PZ |
1489 | ret = (*up)(parent, data); |
1490 | if (ret) | |
1491 | goto out_unlock; | |
c09595f6 PZ |
1492 | |
1493 | child = parent; | |
1494 | parent = parent->parent; | |
1495 | if (parent) | |
1496 | goto up; | |
eb755805 | 1497 | out_unlock: |
c09595f6 | 1498 | rcu_read_unlock(); |
eb755805 PZ |
1499 | |
1500 | return ret; | |
c09595f6 PZ |
1501 | } |
1502 | ||
eb755805 PZ |
1503 | static int tg_nop(struct task_group *tg, void *data) |
1504 | { | |
1505 | return 0; | |
c09595f6 | 1506 | } |
eb755805 PZ |
1507 | #endif |
1508 | ||
1509 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1510 | /* Used instead of source_load when we know the type == 0 */ |
1511 | static unsigned long weighted_cpuload(const int cpu) | |
1512 | { | |
1513 | return cpu_rq(cpu)->load.weight; | |
1514 | } | |
1515 | ||
1516 | /* | |
1517 | * Return a low guess at the load of a migration-source cpu weighted | |
1518 | * according to the scheduling class and "nice" value. | |
1519 | * | |
1520 | * We want to under-estimate the load of migration sources, to | |
1521 | * balance conservatively. | |
1522 | */ | |
1523 | static unsigned long source_load(int cpu, int type) | |
1524 | { | |
1525 | struct rq *rq = cpu_rq(cpu); | |
1526 | unsigned long total = weighted_cpuload(cpu); | |
1527 | ||
1528 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1529 | return total; | |
1530 | ||
1531 | return min(rq->cpu_load[type-1], total); | |
1532 | } | |
1533 | ||
1534 | /* | |
1535 | * Return a high guess at the load of a migration-target cpu weighted | |
1536 | * according to the scheduling class and "nice" value. | |
1537 | */ | |
1538 | static unsigned long target_load(int cpu, int type) | |
1539 | { | |
1540 | struct rq *rq = cpu_rq(cpu); | |
1541 | unsigned long total = weighted_cpuload(cpu); | |
1542 | ||
1543 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1544 | return total; | |
1545 | ||
1546 | return max(rq->cpu_load[type-1], total); | |
1547 | } | |
1548 | ||
eb755805 PZ |
1549 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1550 | ||
1551 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1552 | { | |
1553 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1554 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1555 | |
4cd42620 SR |
1556 | if (nr_running) |
1557 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1558 | else |
1559 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1560 | |
1561 | return rq->avg_load_per_task; | |
1562 | } | |
1563 | ||
1564 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1565 | |
34d76c41 PZ |
1566 | struct update_shares_data { |
1567 | unsigned long rq_weight[NR_CPUS]; | |
1568 | }; | |
1569 | ||
1570 | static DEFINE_PER_CPU(struct update_shares_data, update_shares_data); | |
1571 | ||
c09595f6 PZ |
1572 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1573 | ||
1574 | /* | |
1575 | * Calculate and set the cpu's group shares. | |
1576 | */ | |
34d76c41 PZ |
1577 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1578 | unsigned long sd_shares, | |
1579 | unsigned long sd_rq_weight, | |
1580 | struct update_shares_data *usd) | |
18d95a28 | 1581 | { |
34d76c41 | 1582 | unsigned long shares, rq_weight; |
a5004278 | 1583 | int boost = 0; |
c09595f6 | 1584 | |
34d76c41 | 1585 | rq_weight = usd->rq_weight[cpu]; |
a5004278 PZ |
1586 | if (!rq_weight) { |
1587 | boost = 1; | |
1588 | rq_weight = NICE_0_LOAD; | |
1589 | } | |
c8cba857 | 1590 | |
c09595f6 | 1591 | /* |
a8af7246 PZ |
1592 | * \Sum_j shares_j * rq_weight_i |
1593 | * shares_i = ----------------------------- | |
1594 | * \Sum_j rq_weight_j | |
c09595f6 | 1595 | */ |
ec4e0e2f | 1596 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1597 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1598 | |
ffda12a1 PZ |
1599 | if (abs(shares - tg->se[cpu]->load.weight) > |
1600 | sysctl_sched_shares_thresh) { | |
1601 | struct rq *rq = cpu_rq(cpu); | |
1602 | unsigned long flags; | |
c09595f6 | 1603 | |
ffda12a1 | 1604 | spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1605 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1606 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 PZ |
1607 | __set_se_shares(tg->se[cpu], shares); |
1608 | spin_unlock_irqrestore(&rq->lock, flags); | |
1609 | } | |
18d95a28 | 1610 | } |
c09595f6 PZ |
1611 | |
1612 | /* | |
c8cba857 PZ |
1613 | * Re-compute the task group their per cpu shares over the given domain. |
1614 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1615 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1616 | */ |
eb755805 | 1617 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1618 | { |
34d76c41 PZ |
1619 | unsigned long weight, rq_weight = 0, shares = 0; |
1620 | struct update_shares_data *usd; | |
eb755805 | 1621 | struct sched_domain *sd = data; |
34d76c41 | 1622 | unsigned long flags; |
c8cba857 | 1623 | int i; |
c09595f6 | 1624 | |
34d76c41 PZ |
1625 | if (!tg->se[0]) |
1626 | return 0; | |
1627 | ||
1628 | local_irq_save(flags); | |
1629 | usd = &__get_cpu_var(update_shares_data); | |
1630 | ||
758b2cdc | 1631 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 PZ |
1632 | weight = tg->cfs_rq[i]->load.weight; |
1633 | usd->rq_weight[i] = weight; | |
1634 | ||
ec4e0e2f KC |
1635 | /* |
1636 | * If there are currently no tasks on the cpu pretend there | |
1637 | * is one of average load so that when a new task gets to | |
1638 | * run here it will not get delayed by group starvation. | |
1639 | */ | |
ec4e0e2f KC |
1640 | if (!weight) |
1641 | weight = NICE_0_LOAD; | |
1642 | ||
ec4e0e2f | 1643 | rq_weight += weight; |
c8cba857 | 1644 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1645 | } |
c09595f6 | 1646 | |
c8cba857 PZ |
1647 | if ((!shares && rq_weight) || shares > tg->shares) |
1648 | shares = tg->shares; | |
1649 | ||
1650 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1651 | shares = tg->shares; | |
c09595f6 | 1652 | |
758b2cdc | 1653 | for_each_cpu(i, sched_domain_span(sd)) |
34d76c41 PZ |
1654 | update_group_shares_cpu(tg, i, shares, rq_weight, usd); |
1655 | ||
1656 | local_irq_restore(flags); | |
eb755805 PZ |
1657 | |
1658 | return 0; | |
c09595f6 PZ |
1659 | } |
1660 | ||
1661 | /* | |
c8cba857 PZ |
1662 | * Compute the cpu's hierarchical load factor for each task group. |
1663 | * This needs to be done in a top-down fashion because the load of a child | |
1664 | * group is a fraction of its parents load. | |
c09595f6 | 1665 | */ |
eb755805 | 1666 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1667 | { |
c8cba857 | 1668 | unsigned long load; |
eb755805 | 1669 | long cpu = (long)data; |
c09595f6 | 1670 | |
c8cba857 PZ |
1671 | if (!tg->parent) { |
1672 | load = cpu_rq(cpu)->load.weight; | |
1673 | } else { | |
1674 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1675 | load *= tg->cfs_rq[cpu]->shares; | |
1676 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1677 | } | |
c09595f6 | 1678 | |
c8cba857 | 1679 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1680 | |
eb755805 | 1681 | return 0; |
c09595f6 PZ |
1682 | } |
1683 | ||
c8cba857 | 1684 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1685 | { |
e7097159 PZ |
1686 | s64 elapsed; |
1687 | u64 now; | |
1688 | ||
1689 | if (root_task_group_empty()) | |
1690 | return; | |
1691 | ||
1692 | now = cpu_clock(raw_smp_processor_id()); | |
1693 | elapsed = now - sd->last_update; | |
2398f2c6 PZ |
1694 | |
1695 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1696 | sd->last_update = now; | |
eb755805 | 1697 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1698 | } |
4d8d595d PZ |
1699 | } |
1700 | ||
3e5459b4 PZ |
1701 | static void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1702 | { | |
e7097159 PZ |
1703 | if (root_task_group_empty()) |
1704 | return; | |
1705 | ||
3e5459b4 PZ |
1706 | spin_unlock(&rq->lock); |
1707 | update_shares(sd); | |
1708 | spin_lock(&rq->lock); | |
1709 | } | |
1710 | ||
eb755805 | 1711 | static void update_h_load(long cpu) |
c09595f6 | 1712 | { |
e7097159 PZ |
1713 | if (root_task_group_empty()) |
1714 | return; | |
1715 | ||
eb755805 | 1716 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1717 | } |
1718 | ||
c09595f6 PZ |
1719 | #else |
1720 | ||
c8cba857 | 1721 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1722 | { |
1723 | } | |
1724 | ||
3e5459b4 PZ |
1725 | static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1726 | { | |
1727 | } | |
1728 | ||
18d95a28 PZ |
1729 | #endif |
1730 | ||
8f45e2b5 GH |
1731 | #ifdef CONFIG_PREEMPT |
1732 | ||
b78bb868 PZ |
1733 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1734 | ||
70574a99 | 1735 | /* |
8f45e2b5 GH |
1736 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1737 | * way at the expense of forcing extra atomic operations in all | |
1738 | * invocations. This assures that the double_lock is acquired using the | |
1739 | * same underlying policy as the spinlock_t on this architecture, which | |
1740 | * reduces latency compared to the unfair variant below. However, it | |
1741 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1742 | */ |
8f45e2b5 GH |
1743 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1744 | __releases(this_rq->lock) | |
1745 | __acquires(busiest->lock) | |
1746 | __acquires(this_rq->lock) | |
1747 | { | |
1748 | spin_unlock(&this_rq->lock); | |
1749 | double_rq_lock(this_rq, busiest); | |
1750 | ||
1751 | return 1; | |
1752 | } | |
1753 | ||
1754 | #else | |
1755 | /* | |
1756 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1757 | * latency by eliminating extra atomic operations when the locks are | |
1758 | * already in proper order on entry. This favors lower cpu-ids and will | |
1759 | * grant the double lock to lower cpus over higher ids under contention, | |
1760 | * regardless of entry order into the function. | |
1761 | */ | |
1762 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1763 | __releases(this_rq->lock) |
1764 | __acquires(busiest->lock) | |
1765 | __acquires(this_rq->lock) | |
1766 | { | |
1767 | int ret = 0; | |
1768 | ||
70574a99 AD |
1769 | if (unlikely(!spin_trylock(&busiest->lock))) { |
1770 | if (busiest < this_rq) { | |
1771 | spin_unlock(&this_rq->lock); | |
1772 | spin_lock(&busiest->lock); | |
1773 | spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); | |
1774 | ret = 1; | |
1775 | } else | |
1776 | spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); | |
1777 | } | |
1778 | return ret; | |
1779 | } | |
1780 | ||
8f45e2b5 GH |
1781 | #endif /* CONFIG_PREEMPT */ |
1782 | ||
1783 | /* | |
1784 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1785 | */ | |
1786 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1787 | { | |
1788 | if (unlikely(!irqs_disabled())) { | |
1789 | /* printk() doesn't work good under rq->lock */ | |
1790 | spin_unlock(&this_rq->lock); | |
1791 | BUG_ON(1); | |
1792 | } | |
1793 | ||
1794 | return _double_lock_balance(this_rq, busiest); | |
1795 | } | |
1796 | ||
70574a99 AD |
1797 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1798 | __releases(busiest->lock) | |
1799 | { | |
1800 | spin_unlock(&busiest->lock); | |
1801 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); | |
1802 | } | |
18d95a28 PZ |
1803 | #endif |
1804 | ||
30432094 | 1805 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1806 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1807 | { | |
30432094 | 1808 | #ifdef CONFIG_SMP |
34e83e85 IM |
1809 | cfs_rq->shares = shares; |
1810 | #endif | |
1811 | } | |
30432094 | 1812 | #endif |
e7693a36 | 1813 | |
dce48a84 TG |
1814 | static void calc_load_account_active(struct rq *this_rq); |
1815 | ||
dd41f596 | 1816 | #include "sched_stats.h" |
dd41f596 | 1817 | #include "sched_idletask.c" |
5522d5d5 IM |
1818 | #include "sched_fair.c" |
1819 | #include "sched_rt.c" | |
dd41f596 IM |
1820 | #ifdef CONFIG_SCHED_DEBUG |
1821 | # include "sched_debug.c" | |
1822 | #endif | |
1823 | ||
1824 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1825 | #define for_each_class(class) \ |
1826 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1827 | |
c09595f6 | 1828 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1829 | { |
1830 | rq->nr_running++; | |
9c217245 IM |
1831 | } |
1832 | ||
c09595f6 | 1833 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1834 | { |
1835 | rq->nr_running--; | |
9c217245 IM |
1836 | } |
1837 | ||
45bf76df IM |
1838 | static void set_load_weight(struct task_struct *p) |
1839 | { | |
1840 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1841 | p->se.load.weight = prio_to_weight[0] * 2; |
1842 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1843 | return; | |
1844 | } | |
45bf76df | 1845 | |
dd41f596 IM |
1846 | /* |
1847 | * SCHED_IDLE tasks get minimal weight: | |
1848 | */ | |
1849 | if (p->policy == SCHED_IDLE) { | |
1850 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1851 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1852 | return; | |
1853 | } | |
71f8bd46 | 1854 | |
dd41f596 IM |
1855 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1856 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1857 | } |
1858 | ||
2087a1ad GH |
1859 | static void update_avg(u64 *avg, u64 sample) |
1860 | { | |
1861 | s64 diff = sample - *avg; | |
1862 | *avg += diff >> 3; | |
1863 | } | |
1864 | ||
8159f87e | 1865 | static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) |
71f8bd46 | 1866 | { |
831451ac PZ |
1867 | if (wakeup) |
1868 | p->se.start_runtime = p->se.sum_exec_runtime; | |
1869 | ||
dd41f596 | 1870 | sched_info_queued(p); |
fd390f6a | 1871 | p->sched_class->enqueue_task(rq, p, wakeup); |
dd41f596 | 1872 | p->se.on_rq = 1; |
71f8bd46 IM |
1873 | } |
1874 | ||
69be72c1 | 1875 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1876 | { |
831451ac PZ |
1877 | if (sleep) { |
1878 | if (p->se.last_wakeup) { | |
1879 | update_avg(&p->se.avg_overlap, | |
1880 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1881 | p->se.last_wakeup = 0; | |
1882 | } else { | |
1883 | update_avg(&p->se.avg_wakeup, | |
1884 | sysctl_sched_wakeup_granularity); | |
1885 | } | |
2087a1ad GH |
1886 | } |
1887 | ||
46ac22ba | 1888 | sched_info_dequeued(p); |
f02231e5 | 1889 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1890 | p->se.on_rq = 0; |
71f8bd46 IM |
1891 | } |
1892 | ||
14531189 | 1893 | /* |
dd41f596 | 1894 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1895 | */ |
14531189 IM |
1896 | static inline int __normal_prio(struct task_struct *p) |
1897 | { | |
dd41f596 | 1898 | return p->static_prio; |
14531189 IM |
1899 | } |
1900 | ||
b29739f9 IM |
1901 | /* |
1902 | * Calculate the expected normal priority: i.e. priority | |
1903 | * without taking RT-inheritance into account. Might be | |
1904 | * boosted by interactivity modifiers. Changes upon fork, | |
1905 | * setprio syscalls, and whenever the interactivity | |
1906 | * estimator recalculates. | |
1907 | */ | |
36c8b586 | 1908 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1909 | { |
1910 | int prio; | |
1911 | ||
e05606d3 | 1912 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1913 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1914 | else | |
1915 | prio = __normal_prio(p); | |
1916 | return prio; | |
1917 | } | |
1918 | ||
1919 | /* | |
1920 | * Calculate the current priority, i.e. the priority | |
1921 | * taken into account by the scheduler. This value might | |
1922 | * be boosted by RT tasks, or might be boosted by | |
1923 | * interactivity modifiers. Will be RT if the task got | |
1924 | * RT-boosted. If not then it returns p->normal_prio. | |
1925 | */ | |
36c8b586 | 1926 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1927 | { |
1928 | p->normal_prio = normal_prio(p); | |
1929 | /* | |
1930 | * If we are RT tasks or we were boosted to RT priority, | |
1931 | * keep the priority unchanged. Otherwise, update priority | |
1932 | * to the normal priority: | |
1933 | */ | |
1934 | if (!rt_prio(p->prio)) | |
1935 | return p->normal_prio; | |
1936 | return p->prio; | |
1937 | } | |
1938 | ||
1da177e4 | 1939 | /* |
dd41f596 | 1940 | * activate_task - move a task to the runqueue. |
1da177e4 | 1941 | */ |
dd41f596 | 1942 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) |
1da177e4 | 1943 | { |
d9514f6c | 1944 | if (task_contributes_to_load(p)) |
dd41f596 | 1945 | rq->nr_uninterruptible--; |
1da177e4 | 1946 | |
8159f87e | 1947 | enqueue_task(rq, p, wakeup); |
c09595f6 | 1948 | inc_nr_running(rq); |
1da177e4 LT |
1949 | } |
1950 | ||
1da177e4 LT |
1951 | /* |
1952 | * deactivate_task - remove a task from the runqueue. | |
1953 | */ | |
2e1cb74a | 1954 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) |
1da177e4 | 1955 | { |
d9514f6c | 1956 | if (task_contributes_to_load(p)) |
dd41f596 IM |
1957 | rq->nr_uninterruptible++; |
1958 | ||
69be72c1 | 1959 | dequeue_task(rq, p, sleep); |
c09595f6 | 1960 | dec_nr_running(rq); |
1da177e4 LT |
1961 | } |
1962 | ||
1da177e4 LT |
1963 | /** |
1964 | * task_curr - is this task currently executing on a CPU? | |
1965 | * @p: the task in question. | |
1966 | */ | |
36c8b586 | 1967 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1968 | { |
1969 | return cpu_curr(task_cpu(p)) == p; | |
1970 | } | |
1971 | ||
dd41f596 IM |
1972 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1973 | { | |
6f505b16 | 1974 | set_task_rq(p, cpu); |
dd41f596 | 1975 | #ifdef CONFIG_SMP |
ce96b5ac DA |
1976 | /* |
1977 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1978 | * successfuly executed on another CPU. We must ensure that updates of | |
1979 | * per-task data have been completed by this moment. | |
1980 | */ | |
1981 | smp_wmb(); | |
dd41f596 | 1982 | task_thread_info(p)->cpu = cpu; |
dd41f596 | 1983 | #endif |
2dd73a4f PW |
1984 | } |
1985 | ||
cb469845 SR |
1986 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1987 | const struct sched_class *prev_class, | |
1988 | int oldprio, int running) | |
1989 | { | |
1990 | if (prev_class != p->sched_class) { | |
1991 | if (prev_class->switched_from) | |
1992 | prev_class->switched_from(rq, p, running); | |
1993 | p->sched_class->switched_to(rq, p, running); | |
1994 | } else | |
1995 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1996 | } | |
1997 | ||
1da177e4 | 1998 | #ifdef CONFIG_SMP |
cc367732 IM |
1999 | /* |
2000 | * Is this task likely cache-hot: | |
2001 | */ | |
e7693a36 | 2002 | static int |
cc367732 IM |
2003 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2004 | { | |
2005 | s64 delta; | |
2006 | ||
f540a608 IM |
2007 | /* |
2008 | * Buddy candidates are cache hot: | |
2009 | */ | |
4793241b PZ |
2010 | if (sched_feat(CACHE_HOT_BUDDY) && |
2011 | (&p->se == cfs_rq_of(&p->se)->next || | |
2012 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2013 | return 1; |
2014 | ||
cc367732 IM |
2015 | if (p->sched_class != &fair_sched_class) |
2016 | return 0; | |
2017 | ||
6bc1665b IM |
2018 | if (sysctl_sched_migration_cost == -1) |
2019 | return 1; | |
2020 | if (sysctl_sched_migration_cost == 0) | |
2021 | return 0; | |
2022 | ||
cc367732 IM |
2023 | delta = now - p->se.exec_start; |
2024 | ||
2025 | return delta < (s64)sysctl_sched_migration_cost; | |
2026 | } | |
2027 | ||
2028 | ||
dd41f596 | 2029 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2030 | { |
dd41f596 IM |
2031 | int old_cpu = task_cpu(p); |
2032 | struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu); | |
2830cf8c SV |
2033 | struct cfs_rq *old_cfsrq = task_cfs_rq(p), |
2034 | *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); | |
bbdba7c0 | 2035 | u64 clock_offset; |
dd41f596 IM |
2036 | |
2037 | clock_offset = old_rq->clock - new_rq->clock; | |
6cfb0d5d | 2038 | |
de1d7286 | 2039 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2040 | |
6cfb0d5d IM |
2041 | #ifdef CONFIG_SCHEDSTATS |
2042 | if (p->se.wait_start) | |
2043 | p->se.wait_start -= clock_offset; | |
dd41f596 IM |
2044 | if (p->se.sleep_start) |
2045 | p->se.sleep_start -= clock_offset; | |
2046 | if (p->se.block_start) | |
2047 | p->se.block_start -= clock_offset; | |
6c594c21 | 2048 | #endif |
cc367732 | 2049 | if (old_cpu != new_cpu) { |
6c594c21 | 2050 | p->se.nr_migrations++; |
23a185ca | 2051 | new_rq->nr_migrations_in++; |
6c594c21 | 2052 | #ifdef CONFIG_SCHEDSTATS |
cc367732 IM |
2053 | if (task_hot(p, old_rq->clock, NULL)) |
2054 | schedstat_inc(p, se.nr_forced2_migrations); | |
6cfb0d5d | 2055 | #endif |
e5289d4a PZ |
2056 | perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS, |
2057 | 1, 1, NULL, 0); | |
6c594c21 | 2058 | } |
2830cf8c SV |
2059 | p->se.vruntime -= old_cfsrq->min_vruntime - |
2060 | new_cfsrq->min_vruntime; | |
dd41f596 IM |
2061 | |
2062 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2063 | } |
2064 | ||
70b97a7f | 2065 | struct migration_req { |
1da177e4 | 2066 | struct list_head list; |
1da177e4 | 2067 | |
36c8b586 | 2068 | struct task_struct *task; |
1da177e4 LT |
2069 | int dest_cpu; |
2070 | ||
1da177e4 | 2071 | struct completion done; |
70b97a7f | 2072 | }; |
1da177e4 LT |
2073 | |
2074 | /* | |
2075 | * The task's runqueue lock must be held. | |
2076 | * Returns true if you have to wait for migration thread. | |
2077 | */ | |
36c8b586 | 2078 | static int |
70b97a7f | 2079 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 2080 | { |
70b97a7f | 2081 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2082 | |
2083 | /* | |
2084 | * If the task is not on a runqueue (and not running), then | |
2085 | * it is sufficient to simply update the task's cpu field. | |
2086 | */ | |
dd41f596 | 2087 | if (!p->se.on_rq && !task_running(rq, p)) { |
1da177e4 LT |
2088 | set_task_cpu(p, dest_cpu); |
2089 | return 0; | |
2090 | } | |
2091 | ||
2092 | init_completion(&req->done); | |
1da177e4 LT |
2093 | req->task = p; |
2094 | req->dest_cpu = dest_cpu; | |
2095 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 2096 | |
1da177e4 LT |
2097 | return 1; |
2098 | } | |
2099 | ||
a26b89f0 MM |
2100 | /* |
2101 | * wait_task_context_switch - wait for a thread to complete at least one | |
2102 | * context switch. | |
2103 | * | |
2104 | * @p must not be current. | |
2105 | */ | |
2106 | void wait_task_context_switch(struct task_struct *p) | |
2107 | { | |
2108 | unsigned long nvcsw, nivcsw, flags; | |
2109 | int running; | |
2110 | struct rq *rq; | |
2111 | ||
2112 | nvcsw = p->nvcsw; | |
2113 | nivcsw = p->nivcsw; | |
2114 | for (;;) { | |
2115 | /* | |
2116 | * The runqueue is assigned before the actual context | |
2117 | * switch. We need to take the runqueue lock. | |
2118 | * | |
2119 | * We could check initially without the lock but it is | |
2120 | * very likely that we need to take the lock in every | |
2121 | * iteration. | |
2122 | */ | |
2123 | rq = task_rq_lock(p, &flags); | |
2124 | running = task_running(rq, p); | |
2125 | task_rq_unlock(rq, &flags); | |
2126 | ||
2127 | if (likely(!running)) | |
2128 | break; | |
2129 | /* | |
2130 | * The switch count is incremented before the actual | |
2131 | * context switch. We thus wait for two switches to be | |
2132 | * sure at least one completed. | |
2133 | */ | |
2134 | if ((p->nvcsw - nvcsw) > 1) | |
2135 | break; | |
2136 | if ((p->nivcsw - nivcsw) > 1) | |
2137 | break; | |
2138 | ||
2139 | cpu_relax(); | |
2140 | } | |
2141 | } | |
2142 | ||
1da177e4 LT |
2143 | /* |
2144 | * wait_task_inactive - wait for a thread to unschedule. | |
2145 | * | |
85ba2d86 RM |
2146 | * If @match_state is nonzero, it's the @p->state value just checked and |
2147 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2148 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2149 | * we return a positive number (its total switch count). If a second call | |
2150 | * a short while later returns the same number, the caller can be sure that | |
2151 | * @p has remained unscheduled the whole time. | |
2152 | * | |
1da177e4 LT |
2153 | * The caller must ensure that the task *will* unschedule sometime soon, |
2154 | * else this function might spin for a *long* time. This function can't | |
2155 | * be called with interrupts off, or it may introduce deadlock with | |
2156 | * smp_call_function() if an IPI is sent by the same process we are | |
2157 | * waiting to become inactive. | |
2158 | */ | |
85ba2d86 | 2159 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2160 | { |
2161 | unsigned long flags; | |
dd41f596 | 2162 | int running, on_rq; |
85ba2d86 | 2163 | unsigned long ncsw; |
70b97a7f | 2164 | struct rq *rq; |
1da177e4 | 2165 | |
3a5c359a AK |
2166 | for (;;) { |
2167 | /* | |
2168 | * We do the initial early heuristics without holding | |
2169 | * any task-queue locks at all. We'll only try to get | |
2170 | * the runqueue lock when things look like they will | |
2171 | * work out! | |
2172 | */ | |
2173 | rq = task_rq(p); | |
fa490cfd | 2174 | |
3a5c359a AK |
2175 | /* |
2176 | * If the task is actively running on another CPU | |
2177 | * still, just relax and busy-wait without holding | |
2178 | * any locks. | |
2179 | * | |
2180 | * NOTE! Since we don't hold any locks, it's not | |
2181 | * even sure that "rq" stays as the right runqueue! | |
2182 | * But we don't care, since "task_running()" will | |
2183 | * return false if the runqueue has changed and p | |
2184 | * is actually now running somewhere else! | |
2185 | */ | |
85ba2d86 RM |
2186 | while (task_running(rq, p)) { |
2187 | if (match_state && unlikely(p->state != match_state)) | |
2188 | return 0; | |
3a5c359a | 2189 | cpu_relax(); |
85ba2d86 | 2190 | } |
fa490cfd | 2191 | |
3a5c359a AK |
2192 | /* |
2193 | * Ok, time to look more closely! We need the rq | |
2194 | * lock now, to be *sure*. If we're wrong, we'll | |
2195 | * just go back and repeat. | |
2196 | */ | |
2197 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 2198 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
2199 | running = task_running(rq, p); |
2200 | on_rq = p->se.on_rq; | |
85ba2d86 | 2201 | ncsw = 0; |
f31e11d8 | 2202 | if (!match_state || p->state == match_state) |
93dcf55f | 2203 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2204 | task_rq_unlock(rq, &flags); |
fa490cfd | 2205 | |
85ba2d86 RM |
2206 | /* |
2207 | * If it changed from the expected state, bail out now. | |
2208 | */ | |
2209 | if (unlikely(!ncsw)) | |
2210 | break; | |
2211 | ||
3a5c359a AK |
2212 | /* |
2213 | * Was it really running after all now that we | |
2214 | * checked with the proper locks actually held? | |
2215 | * | |
2216 | * Oops. Go back and try again.. | |
2217 | */ | |
2218 | if (unlikely(running)) { | |
2219 | cpu_relax(); | |
2220 | continue; | |
2221 | } | |
fa490cfd | 2222 | |
3a5c359a AK |
2223 | /* |
2224 | * It's not enough that it's not actively running, | |
2225 | * it must be off the runqueue _entirely_, and not | |
2226 | * preempted! | |
2227 | * | |
80dd99b3 | 2228 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2229 | * running right now), it's preempted, and we should |
2230 | * yield - it could be a while. | |
2231 | */ | |
2232 | if (unlikely(on_rq)) { | |
2233 | schedule_timeout_uninterruptible(1); | |
2234 | continue; | |
2235 | } | |
fa490cfd | 2236 | |
3a5c359a AK |
2237 | /* |
2238 | * Ahh, all good. It wasn't running, and it wasn't | |
2239 | * runnable, which means that it will never become | |
2240 | * running in the future either. We're all done! | |
2241 | */ | |
2242 | break; | |
2243 | } | |
85ba2d86 RM |
2244 | |
2245 | return ncsw; | |
1da177e4 LT |
2246 | } |
2247 | ||
2248 | /*** | |
2249 | * kick_process - kick a running thread to enter/exit the kernel | |
2250 | * @p: the to-be-kicked thread | |
2251 | * | |
2252 | * Cause a process which is running on another CPU to enter | |
2253 | * kernel-mode, without any delay. (to get signals handled.) | |
2254 | * | |
2255 | * NOTE: this function doesnt have to take the runqueue lock, | |
2256 | * because all it wants to ensure is that the remote task enters | |
2257 | * the kernel. If the IPI races and the task has been migrated | |
2258 | * to another CPU then no harm is done and the purpose has been | |
2259 | * achieved as well. | |
2260 | */ | |
36c8b586 | 2261 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2262 | { |
2263 | int cpu; | |
2264 | ||
2265 | preempt_disable(); | |
2266 | cpu = task_cpu(p); | |
2267 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2268 | smp_send_reschedule(cpu); | |
2269 | preempt_enable(); | |
2270 | } | |
b43e3521 | 2271 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2272 | #endif /* CONFIG_SMP */ |
1da177e4 | 2273 | |
0793a61d TG |
2274 | /** |
2275 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2276 | * @p: the task to evaluate | |
2277 | * @func: the function to be called | |
2278 | * @info: the function call argument | |
2279 | * | |
2280 | * Calls the function @func when the task is currently running. This might | |
2281 | * be on the current CPU, which just calls the function directly | |
2282 | */ | |
2283 | void task_oncpu_function_call(struct task_struct *p, | |
2284 | void (*func) (void *info), void *info) | |
2285 | { | |
2286 | int cpu; | |
2287 | ||
2288 | preempt_disable(); | |
2289 | cpu = task_cpu(p); | |
2290 | if (task_curr(p)) | |
2291 | smp_call_function_single(cpu, func, info, 1); | |
2292 | preempt_enable(); | |
2293 | } | |
2294 | ||
1da177e4 LT |
2295 | /*** |
2296 | * try_to_wake_up - wake up a thread | |
2297 | * @p: the to-be-woken-up thread | |
2298 | * @state: the mask of task states that can be woken | |
2299 | * @sync: do a synchronous wakeup? | |
2300 | * | |
2301 | * Put it on the run-queue if it's not already there. The "current" | |
2302 | * thread is always on the run-queue (except when the actual | |
2303 | * re-schedule is in progress), and as such you're allowed to do | |
2304 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2305 | * runnable without the overhead of this. | |
2306 | * | |
2307 | * returns failure only if the task is already active. | |
2308 | */ | |
36c8b586 | 2309 | static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) |
1da177e4 | 2310 | { |
cc367732 | 2311 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 LT |
2312 | unsigned long flags; |
2313 | long old_state; | |
70b97a7f | 2314 | struct rq *rq; |
1da177e4 | 2315 | |
b85d0667 IM |
2316 | if (!sched_feat(SYNC_WAKEUPS)) |
2317 | sync = 0; | |
2318 | ||
2398f2c6 | 2319 | #ifdef CONFIG_SMP |
57310a98 | 2320 | if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) { |
2398f2c6 PZ |
2321 | struct sched_domain *sd; |
2322 | ||
2323 | this_cpu = raw_smp_processor_id(); | |
2324 | cpu = task_cpu(p); | |
2325 | ||
2326 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2327 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
2398f2c6 PZ |
2328 | update_shares(sd); |
2329 | break; | |
2330 | } | |
2331 | } | |
2332 | } | |
2333 | #endif | |
2334 | ||
04e2f174 | 2335 | smp_wmb(); |
1da177e4 | 2336 | rq = task_rq_lock(p, &flags); |
03e89e45 | 2337 | update_rq_clock(rq); |
1da177e4 LT |
2338 | old_state = p->state; |
2339 | if (!(old_state & state)) | |
2340 | goto out; | |
2341 | ||
dd41f596 | 2342 | if (p->se.on_rq) |
1da177e4 LT |
2343 | goto out_running; |
2344 | ||
2345 | cpu = task_cpu(p); | |
cc367732 | 2346 | orig_cpu = cpu; |
1da177e4 LT |
2347 | this_cpu = smp_processor_id(); |
2348 | ||
2349 | #ifdef CONFIG_SMP | |
2350 | if (unlikely(task_running(rq, p))) | |
2351 | goto out_activate; | |
2352 | ||
5d2f5a61 DA |
2353 | cpu = p->sched_class->select_task_rq(p, sync); |
2354 | if (cpu != orig_cpu) { | |
2355 | set_task_cpu(p, cpu); | |
1da177e4 LT |
2356 | task_rq_unlock(rq, &flags); |
2357 | /* might preempt at this point */ | |
2358 | rq = task_rq_lock(p, &flags); | |
2359 | old_state = p->state; | |
2360 | if (!(old_state & state)) | |
2361 | goto out; | |
dd41f596 | 2362 | if (p->se.on_rq) |
1da177e4 LT |
2363 | goto out_running; |
2364 | ||
2365 | this_cpu = smp_processor_id(); | |
2366 | cpu = task_cpu(p); | |
2367 | } | |
2368 | ||
e7693a36 GH |
2369 | #ifdef CONFIG_SCHEDSTATS |
2370 | schedstat_inc(rq, ttwu_count); | |
2371 | if (cpu == this_cpu) | |
2372 | schedstat_inc(rq, ttwu_local); | |
2373 | else { | |
2374 | struct sched_domain *sd; | |
2375 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2376 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2377 | schedstat_inc(sd, ttwu_wake_remote); |
2378 | break; | |
2379 | } | |
2380 | } | |
2381 | } | |
6d6bc0ad | 2382 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2383 | |
1da177e4 LT |
2384 | out_activate: |
2385 | #endif /* CONFIG_SMP */ | |
cc367732 IM |
2386 | schedstat_inc(p, se.nr_wakeups); |
2387 | if (sync) | |
2388 | schedstat_inc(p, se.nr_wakeups_sync); | |
2389 | if (orig_cpu != cpu) | |
2390 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2391 | if (cpu == this_cpu) | |
2392 | schedstat_inc(p, se.nr_wakeups_local); | |
2393 | else | |
2394 | schedstat_inc(p, se.nr_wakeups_remote); | |
dd41f596 | 2395 | activate_task(rq, p, 1); |
1da177e4 LT |
2396 | success = 1; |
2397 | ||
831451ac PZ |
2398 | /* |
2399 | * Only attribute actual wakeups done by this task. | |
2400 | */ | |
2401 | if (!in_interrupt()) { | |
2402 | struct sched_entity *se = ¤t->se; | |
2403 | u64 sample = se->sum_exec_runtime; | |
2404 | ||
2405 | if (se->last_wakeup) | |
2406 | sample -= se->last_wakeup; | |
2407 | else | |
2408 | sample -= se->start_runtime; | |
2409 | update_avg(&se->avg_wakeup, sample); | |
2410 | ||
2411 | se->last_wakeup = se->sum_exec_runtime; | |
2412 | } | |
2413 | ||
1da177e4 | 2414 | out_running: |
468a15bb | 2415 | trace_sched_wakeup(rq, p, success); |
15afe09b | 2416 | check_preempt_curr(rq, p, sync); |
4ae7d5ce | 2417 | |
1da177e4 | 2418 | p->state = TASK_RUNNING; |
9a897c5a SR |
2419 | #ifdef CONFIG_SMP |
2420 | if (p->sched_class->task_wake_up) | |
2421 | p->sched_class->task_wake_up(rq, p); | |
2422 | #endif | |
1da177e4 LT |
2423 | out: |
2424 | task_rq_unlock(rq, &flags); | |
2425 | ||
2426 | return success; | |
2427 | } | |
2428 | ||
50fa610a DH |
2429 | /** |
2430 | * wake_up_process - Wake up a specific process | |
2431 | * @p: The process to be woken up. | |
2432 | * | |
2433 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2434 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2435 | * running. | |
2436 | * | |
2437 | * It may be assumed that this function implies a write memory barrier before | |
2438 | * changing the task state if and only if any tasks are woken up. | |
2439 | */ | |
7ad5b3a5 | 2440 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2441 | { |
d9514f6c | 2442 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2443 | } |
1da177e4 LT |
2444 | EXPORT_SYMBOL(wake_up_process); |
2445 | ||
7ad5b3a5 | 2446 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2447 | { |
2448 | return try_to_wake_up(p, state, 0); | |
2449 | } | |
2450 | ||
1da177e4 LT |
2451 | /* |
2452 | * Perform scheduler related setup for a newly forked process p. | |
2453 | * p is forked by current. | |
dd41f596 IM |
2454 | * |
2455 | * __sched_fork() is basic setup used by init_idle() too: | |
2456 | */ | |
2457 | static void __sched_fork(struct task_struct *p) | |
2458 | { | |
dd41f596 IM |
2459 | p->se.exec_start = 0; |
2460 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2461 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2462 | p->se.nr_migrations = 0; |
4ae7d5ce IM |
2463 | p->se.last_wakeup = 0; |
2464 | p->se.avg_overlap = 0; | |
831451ac PZ |
2465 | p->se.start_runtime = 0; |
2466 | p->se.avg_wakeup = sysctl_sched_wakeup_granularity; | |
6cfb0d5d IM |
2467 | |
2468 | #ifdef CONFIG_SCHEDSTATS | |
7793527b LDM |
2469 | p->se.wait_start = 0; |
2470 | p->se.wait_max = 0; | |
2471 | p->se.wait_count = 0; | |
2472 | p->se.wait_sum = 0; | |
2473 | ||
2474 | p->se.sleep_start = 0; | |
2475 | p->se.sleep_max = 0; | |
2476 | p->se.sum_sleep_runtime = 0; | |
2477 | ||
2478 | p->se.block_start = 0; | |
2479 | p->se.block_max = 0; | |
2480 | p->se.exec_max = 0; | |
2481 | p->se.slice_max = 0; | |
2482 | ||
2483 | p->se.nr_migrations_cold = 0; | |
2484 | p->se.nr_failed_migrations_affine = 0; | |
2485 | p->se.nr_failed_migrations_running = 0; | |
2486 | p->se.nr_failed_migrations_hot = 0; | |
2487 | p->se.nr_forced_migrations = 0; | |
2488 | p->se.nr_forced2_migrations = 0; | |
2489 | ||
2490 | p->se.nr_wakeups = 0; | |
2491 | p->se.nr_wakeups_sync = 0; | |
2492 | p->se.nr_wakeups_migrate = 0; | |
2493 | p->se.nr_wakeups_local = 0; | |
2494 | p->se.nr_wakeups_remote = 0; | |
2495 | p->se.nr_wakeups_affine = 0; | |
2496 | p->se.nr_wakeups_affine_attempts = 0; | |
2497 | p->se.nr_wakeups_passive = 0; | |
2498 | p->se.nr_wakeups_idle = 0; | |
2499 | ||
6cfb0d5d | 2500 | #endif |
476d139c | 2501 | |
fa717060 | 2502 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2503 | p->se.on_rq = 0; |
4a55bd5e | 2504 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2505 | |
e107be36 AK |
2506 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2507 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2508 | #endif | |
2509 | ||
1da177e4 LT |
2510 | /* |
2511 | * We mark the process as running here, but have not actually | |
2512 | * inserted it onto the runqueue yet. This guarantees that | |
2513 | * nobody will actually run it, and a signal or other external | |
2514 | * event cannot wake it up and insert it on the runqueue either. | |
2515 | */ | |
2516 | p->state = TASK_RUNNING; | |
dd41f596 IM |
2517 | } |
2518 | ||
2519 | /* | |
2520 | * fork()/clone()-time setup: | |
2521 | */ | |
2522 | void sched_fork(struct task_struct *p, int clone_flags) | |
2523 | { | |
2524 | int cpu = get_cpu(); | |
2525 | ||
2526 | __sched_fork(p); | |
2527 | ||
2528 | #ifdef CONFIG_SMP | |
2529 | cpu = sched_balance_self(cpu, SD_BALANCE_FORK); | |
2530 | #endif | |
02e4bac2 | 2531 | set_task_cpu(p, cpu); |
b29739f9 IM |
2532 | |
2533 | /* | |
b9dc29e7 | 2534 | * Make sure we do not leak PI boosting priority to the child. |
b29739f9 IM |
2535 | */ |
2536 | p->prio = current->normal_prio; | |
ca94c442 | 2537 | |
b9dc29e7 MG |
2538 | /* |
2539 | * Revert to default priority/policy on fork if requested. | |
2540 | */ | |
2541 | if (unlikely(p->sched_reset_on_fork)) { | |
2542 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) | |
2543 | p->policy = SCHED_NORMAL; | |
2544 | ||
2545 | if (p->normal_prio < DEFAULT_PRIO) | |
2546 | p->prio = DEFAULT_PRIO; | |
2547 | ||
6c697bdf MG |
2548 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2549 | p->static_prio = NICE_TO_PRIO(0); | |
2550 | set_load_weight(p); | |
2551 | } | |
2552 | ||
b9dc29e7 MG |
2553 | /* |
2554 | * We don't need the reset flag anymore after the fork. It has | |
2555 | * fulfilled its duty: | |
2556 | */ | |
2557 | p->sched_reset_on_fork = 0; | |
2558 | } | |
ca94c442 | 2559 | |
2ddbf952 HS |
2560 | if (!rt_prio(p->prio)) |
2561 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2562 | |
52f17b6c | 2563 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2564 | if (likely(sched_info_on())) |
52f17b6c | 2565 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2566 | #endif |
d6077cb8 | 2567 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2568 | p->oncpu = 0; |
2569 | #endif | |
1da177e4 | 2570 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2571 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2572 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2573 | #endif |
917b627d GH |
2574 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
2575 | ||
476d139c | 2576 | put_cpu(); |
1da177e4 LT |
2577 | } |
2578 | ||
2579 | /* | |
2580 | * wake_up_new_task - wake up a newly created task for the first time. | |
2581 | * | |
2582 | * This function will do some initial scheduler statistics housekeeping | |
2583 | * that must be done for every newly created context, then puts the task | |
2584 | * on the runqueue and wakes it. | |
2585 | */ | |
7ad5b3a5 | 2586 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2587 | { |
2588 | unsigned long flags; | |
dd41f596 | 2589 | struct rq *rq; |
1da177e4 LT |
2590 | |
2591 | rq = task_rq_lock(p, &flags); | |
147cbb4b | 2592 | BUG_ON(p->state != TASK_RUNNING); |
a8e504d2 | 2593 | update_rq_clock(rq); |
1da177e4 LT |
2594 | |
2595 | p->prio = effective_prio(p); | |
2596 | ||
b9dca1e0 | 2597 | if (!p->sched_class->task_new || !current->se.on_rq) { |
dd41f596 | 2598 | activate_task(rq, p, 0); |
1da177e4 | 2599 | } else { |
1da177e4 | 2600 | /* |
dd41f596 IM |
2601 | * Let the scheduling class do new task startup |
2602 | * management (if any): | |
1da177e4 | 2603 | */ |
ee0827d8 | 2604 | p->sched_class->task_new(rq, p); |
c09595f6 | 2605 | inc_nr_running(rq); |
1da177e4 | 2606 | } |
c71dd42d | 2607 | trace_sched_wakeup_new(rq, p, 1); |
15afe09b | 2608 | check_preempt_curr(rq, p, 0); |
9a897c5a SR |
2609 | #ifdef CONFIG_SMP |
2610 | if (p->sched_class->task_wake_up) | |
2611 | p->sched_class->task_wake_up(rq, p); | |
2612 | #endif | |
dd41f596 | 2613 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
2614 | } |
2615 | ||
e107be36 AK |
2616 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2617 | ||
2618 | /** | |
80dd99b3 | 2619 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2620 | * @notifier: notifier struct to register |
e107be36 AK |
2621 | */ |
2622 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2623 | { | |
2624 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2625 | } | |
2626 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2627 | ||
2628 | /** | |
2629 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2630 | * @notifier: notifier struct to unregister |
e107be36 AK |
2631 | * |
2632 | * This is safe to call from within a preemption notifier. | |
2633 | */ | |
2634 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2635 | { | |
2636 | hlist_del(¬ifier->link); | |
2637 | } | |
2638 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2639 | ||
2640 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2641 | { | |
2642 | struct preempt_notifier *notifier; | |
2643 | struct hlist_node *node; | |
2644 | ||
2645 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2646 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2647 | } | |
2648 | ||
2649 | static void | |
2650 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2651 | struct task_struct *next) | |
2652 | { | |
2653 | struct preempt_notifier *notifier; | |
2654 | struct hlist_node *node; | |
2655 | ||
2656 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2657 | notifier->ops->sched_out(notifier, next); | |
2658 | } | |
2659 | ||
6d6bc0ad | 2660 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2661 | |
2662 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2663 | { | |
2664 | } | |
2665 | ||
2666 | static void | |
2667 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2668 | struct task_struct *next) | |
2669 | { | |
2670 | } | |
2671 | ||
6d6bc0ad | 2672 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2673 | |
4866cde0 NP |
2674 | /** |
2675 | * prepare_task_switch - prepare to switch tasks | |
2676 | * @rq: the runqueue preparing to switch | |
421cee29 | 2677 | * @prev: the current task that is being switched out |
4866cde0 NP |
2678 | * @next: the task we are going to switch to. |
2679 | * | |
2680 | * This is called with the rq lock held and interrupts off. It must | |
2681 | * be paired with a subsequent finish_task_switch after the context | |
2682 | * switch. | |
2683 | * | |
2684 | * prepare_task_switch sets up locking and calls architecture specific | |
2685 | * hooks. | |
2686 | */ | |
e107be36 AK |
2687 | static inline void |
2688 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2689 | struct task_struct *next) | |
4866cde0 | 2690 | { |
e107be36 | 2691 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2692 | prepare_lock_switch(rq, next); |
2693 | prepare_arch_switch(next); | |
2694 | } | |
2695 | ||
1da177e4 LT |
2696 | /** |
2697 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2698 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2699 | * @prev: the thread we just switched away from. |
2700 | * | |
4866cde0 NP |
2701 | * finish_task_switch must be called after the context switch, paired |
2702 | * with a prepare_task_switch call before the context switch. | |
2703 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2704 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2705 | * |
2706 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2707 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2708 | * with the lock held can cause deadlocks; see schedule() for |
2709 | * details.) | |
2710 | */ | |
a9957449 | 2711 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2712 | __releases(rq->lock) |
2713 | { | |
1da177e4 | 2714 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2715 | long prev_state; |
1da177e4 LT |
2716 | |
2717 | rq->prev_mm = NULL; | |
2718 | ||
2719 | /* | |
2720 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2721 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2722 | * schedule one last time. The schedule call will never return, and |
2723 | * the scheduled task must drop that reference. | |
c394cc9f | 2724 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2725 | * still held, otherwise prev could be scheduled on another cpu, die |
2726 | * there before we look at prev->state, and then the reference would | |
2727 | * be dropped twice. | |
2728 | * Manfred Spraul <manfred@colorfullife.com> | |
2729 | */ | |
55a101f8 | 2730 | prev_state = prev->state; |
4866cde0 | 2731 | finish_arch_switch(prev); |
0793a61d | 2732 | perf_counter_task_sched_in(current, cpu_of(rq)); |
4866cde0 | 2733 | finish_lock_switch(rq, prev); |
e8fa1362 | 2734 | |
e107be36 | 2735 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2736 | if (mm) |
2737 | mmdrop(mm); | |
c394cc9f | 2738 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2739 | /* |
2740 | * Remove function-return probe instances associated with this | |
2741 | * task and put them back on the free list. | |
9761eea8 | 2742 | */ |
c6fd91f0 | 2743 | kprobe_flush_task(prev); |
1da177e4 | 2744 | put_task_struct(prev); |
c6fd91f0 | 2745 | } |
1da177e4 LT |
2746 | } |
2747 | ||
3f029d3c GH |
2748 | #ifdef CONFIG_SMP |
2749 | ||
2750 | /* assumes rq->lock is held */ | |
2751 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2752 | { | |
2753 | if (prev->sched_class->pre_schedule) | |
2754 | prev->sched_class->pre_schedule(rq, prev); | |
2755 | } | |
2756 | ||
2757 | /* rq->lock is NOT held, but preemption is disabled */ | |
2758 | static inline void post_schedule(struct rq *rq) | |
2759 | { | |
2760 | if (rq->post_schedule) { | |
2761 | unsigned long flags; | |
2762 | ||
2763 | spin_lock_irqsave(&rq->lock, flags); | |
2764 | if (rq->curr->sched_class->post_schedule) | |
2765 | rq->curr->sched_class->post_schedule(rq); | |
2766 | spin_unlock_irqrestore(&rq->lock, flags); | |
2767 | ||
2768 | rq->post_schedule = 0; | |
2769 | } | |
2770 | } | |
2771 | ||
2772 | #else | |
da19ab51 | 2773 | |
3f029d3c GH |
2774 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2775 | { | |
2776 | } | |
2777 | ||
2778 | static inline void post_schedule(struct rq *rq) | |
2779 | { | |
1da177e4 LT |
2780 | } |
2781 | ||
3f029d3c GH |
2782 | #endif |
2783 | ||
1da177e4 LT |
2784 | /** |
2785 | * schedule_tail - first thing a freshly forked thread must call. | |
2786 | * @prev: the thread we just switched away from. | |
2787 | */ | |
36c8b586 | 2788 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2789 | __releases(rq->lock) |
2790 | { | |
70b97a7f IM |
2791 | struct rq *rq = this_rq(); |
2792 | ||
4866cde0 | 2793 | finish_task_switch(rq, prev); |
da19ab51 | 2794 | |
3f029d3c GH |
2795 | /* |
2796 | * FIXME: do we need to worry about rq being invalidated by the | |
2797 | * task_switch? | |
2798 | */ | |
2799 | post_schedule(rq); | |
70b97a7f | 2800 | |
4866cde0 NP |
2801 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2802 | /* In this case, finish_task_switch does not reenable preemption */ | |
2803 | preempt_enable(); | |
2804 | #endif | |
1da177e4 | 2805 | if (current->set_child_tid) |
b488893a | 2806 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2807 | } |
2808 | ||
2809 | /* | |
2810 | * context_switch - switch to the new MM and the new | |
2811 | * thread's register state. | |
2812 | */ | |
dd41f596 | 2813 | static inline void |
70b97a7f | 2814 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2815 | struct task_struct *next) |
1da177e4 | 2816 | { |
dd41f596 | 2817 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2818 | |
e107be36 | 2819 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2820 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2821 | mm = next->mm; |
2822 | oldmm = prev->active_mm; | |
9226d125 ZA |
2823 | /* |
2824 | * For paravirt, this is coupled with an exit in switch_to to | |
2825 | * combine the page table reload and the switch backend into | |
2826 | * one hypercall. | |
2827 | */ | |
224101ed | 2828 | arch_start_context_switch(prev); |
9226d125 | 2829 | |
dd41f596 | 2830 | if (unlikely(!mm)) { |
1da177e4 LT |
2831 | next->active_mm = oldmm; |
2832 | atomic_inc(&oldmm->mm_count); | |
2833 | enter_lazy_tlb(oldmm, next); | |
2834 | } else | |
2835 | switch_mm(oldmm, mm, next); | |
2836 | ||
dd41f596 | 2837 | if (unlikely(!prev->mm)) { |
1da177e4 | 2838 | prev->active_mm = NULL; |
1da177e4 LT |
2839 | rq->prev_mm = oldmm; |
2840 | } | |
3a5f5e48 IM |
2841 | /* |
2842 | * Since the runqueue lock will be released by the next | |
2843 | * task (which is an invalid locking op but in the case | |
2844 | * of the scheduler it's an obvious special-case), so we | |
2845 | * do an early lockdep release here: | |
2846 | */ | |
2847 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2848 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2849 | #endif |
1da177e4 LT |
2850 | |
2851 | /* Here we just switch the register state and the stack. */ | |
2852 | switch_to(prev, next, prev); | |
2853 | ||
dd41f596 IM |
2854 | barrier(); |
2855 | /* | |
2856 | * this_rq must be evaluated again because prev may have moved | |
2857 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2858 | * frame will be invalid. | |
2859 | */ | |
2860 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2861 | } |
2862 | ||
2863 | /* | |
2864 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2865 | * | |
2866 | * externally visible scheduler statistics: current number of runnable | |
2867 | * threads, current number of uninterruptible-sleeping threads, total | |
2868 | * number of context switches performed since bootup. | |
2869 | */ | |
2870 | unsigned long nr_running(void) | |
2871 | { | |
2872 | unsigned long i, sum = 0; | |
2873 | ||
2874 | for_each_online_cpu(i) | |
2875 | sum += cpu_rq(i)->nr_running; | |
2876 | ||
2877 | return sum; | |
2878 | } | |
2879 | ||
2880 | unsigned long nr_uninterruptible(void) | |
2881 | { | |
2882 | unsigned long i, sum = 0; | |
2883 | ||
0a945022 | 2884 | for_each_possible_cpu(i) |
1da177e4 LT |
2885 | sum += cpu_rq(i)->nr_uninterruptible; |
2886 | ||
2887 | /* | |
2888 | * Since we read the counters lockless, it might be slightly | |
2889 | * inaccurate. Do not allow it to go below zero though: | |
2890 | */ | |
2891 | if (unlikely((long)sum < 0)) | |
2892 | sum = 0; | |
2893 | ||
2894 | return sum; | |
2895 | } | |
2896 | ||
2897 | unsigned long long nr_context_switches(void) | |
2898 | { | |
cc94abfc SR |
2899 | int i; |
2900 | unsigned long long sum = 0; | |
1da177e4 | 2901 | |
0a945022 | 2902 | for_each_possible_cpu(i) |
1da177e4 LT |
2903 | sum += cpu_rq(i)->nr_switches; |
2904 | ||
2905 | return sum; | |
2906 | } | |
2907 | ||
2908 | unsigned long nr_iowait(void) | |
2909 | { | |
2910 | unsigned long i, sum = 0; | |
2911 | ||
0a945022 | 2912 | for_each_possible_cpu(i) |
1da177e4 LT |
2913 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
2914 | ||
2915 | return sum; | |
2916 | } | |
2917 | ||
dce48a84 TG |
2918 | /* Variables and functions for calc_load */ |
2919 | static atomic_long_t calc_load_tasks; | |
2920 | static unsigned long calc_load_update; | |
2921 | unsigned long avenrun[3]; | |
2922 | EXPORT_SYMBOL(avenrun); | |
2923 | ||
2d02494f TG |
2924 | /** |
2925 | * get_avenrun - get the load average array | |
2926 | * @loads: pointer to dest load array | |
2927 | * @offset: offset to add | |
2928 | * @shift: shift count to shift the result left | |
2929 | * | |
2930 | * These values are estimates at best, so no need for locking. | |
2931 | */ | |
2932 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
2933 | { | |
2934 | loads[0] = (avenrun[0] + offset) << shift; | |
2935 | loads[1] = (avenrun[1] + offset) << shift; | |
2936 | loads[2] = (avenrun[2] + offset) << shift; | |
2937 | } | |
2938 | ||
dce48a84 TG |
2939 | static unsigned long |
2940 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 2941 | { |
dce48a84 TG |
2942 | load *= exp; |
2943 | load += active * (FIXED_1 - exp); | |
2944 | return load >> FSHIFT; | |
2945 | } | |
db1b1fef | 2946 | |
dce48a84 TG |
2947 | /* |
2948 | * calc_load - update the avenrun load estimates 10 ticks after the | |
2949 | * CPUs have updated calc_load_tasks. | |
2950 | */ | |
2951 | void calc_global_load(void) | |
2952 | { | |
2953 | unsigned long upd = calc_load_update + 10; | |
2954 | long active; | |
2955 | ||
2956 | if (time_before(jiffies, upd)) | |
2957 | return; | |
db1b1fef | 2958 | |
dce48a84 TG |
2959 | active = atomic_long_read(&calc_load_tasks); |
2960 | active = active > 0 ? active * FIXED_1 : 0; | |
db1b1fef | 2961 | |
dce48a84 TG |
2962 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
2963 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
2964 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
2965 | ||
2966 | calc_load_update += LOAD_FREQ; | |
2967 | } | |
2968 | ||
2969 | /* | |
2970 | * Either called from update_cpu_load() or from a cpu going idle | |
2971 | */ | |
2972 | static void calc_load_account_active(struct rq *this_rq) | |
2973 | { | |
2974 | long nr_active, delta; | |
2975 | ||
2976 | nr_active = this_rq->nr_running; | |
2977 | nr_active += (long) this_rq->nr_uninterruptible; | |
2978 | ||
2979 | if (nr_active != this_rq->calc_load_active) { | |
2980 | delta = nr_active - this_rq->calc_load_active; | |
2981 | this_rq->calc_load_active = nr_active; | |
2982 | atomic_long_add(delta, &calc_load_tasks); | |
2983 | } | |
db1b1fef JS |
2984 | } |
2985 | ||
23a185ca PM |
2986 | /* |
2987 | * Externally visible per-cpu scheduler statistics: | |
23a185ca PM |
2988 | * cpu_nr_migrations(cpu) - number of migrations into that cpu |
2989 | */ | |
23a185ca PM |
2990 | u64 cpu_nr_migrations(int cpu) |
2991 | { | |
2992 | return cpu_rq(cpu)->nr_migrations_in; | |
2993 | } | |
2994 | ||
48f24c4d | 2995 | /* |
dd41f596 IM |
2996 | * Update rq->cpu_load[] statistics. This function is usually called every |
2997 | * scheduler tick (TICK_NSEC). | |
48f24c4d | 2998 | */ |
dd41f596 | 2999 | static void update_cpu_load(struct rq *this_rq) |
48f24c4d | 3000 | { |
495eca49 | 3001 | unsigned long this_load = this_rq->load.weight; |
dd41f596 IM |
3002 | int i, scale; |
3003 | ||
3004 | this_rq->nr_load_updates++; | |
dd41f596 IM |
3005 | |
3006 | /* Update our load: */ | |
3007 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
3008 | unsigned long old_load, new_load; | |
3009 | ||
3010 | /* scale is effectively 1 << i now, and >> i divides by scale */ | |
3011 | ||
3012 | old_load = this_rq->cpu_load[i]; | |
3013 | new_load = this_load; | |
a25707f3 IM |
3014 | /* |
3015 | * Round up the averaging division if load is increasing. This | |
3016 | * prevents us from getting stuck on 9 if the load is 10, for | |
3017 | * example. | |
3018 | */ | |
3019 | if (new_load > old_load) | |
3020 | new_load += scale-1; | |
dd41f596 IM |
3021 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
3022 | } | |
dce48a84 TG |
3023 | |
3024 | if (time_after_eq(jiffies, this_rq->calc_load_update)) { | |
3025 | this_rq->calc_load_update += LOAD_FREQ; | |
3026 | calc_load_account_active(this_rq); | |
3027 | } | |
48f24c4d IM |
3028 | } |
3029 | ||
dd41f596 IM |
3030 | #ifdef CONFIG_SMP |
3031 | ||
1da177e4 LT |
3032 | /* |
3033 | * double_rq_lock - safely lock two runqueues | |
3034 | * | |
3035 | * Note this does not disable interrupts like task_rq_lock, | |
3036 | * you need to do so manually before calling. | |
3037 | */ | |
70b97a7f | 3038 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
3039 | __acquires(rq1->lock) |
3040 | __acquires(rq2->lock) | |
3041 | { | |
054b9108 | 3042 | BUG_ON(!irqs_disabled()); |
1da177e4 LT |
3043 | if (rq1 == rq2) { |
3044 | spin_lock(&rq1->lock); | |
3045 | __acquire(rq2->lock); /* Fake it out ;) */ | |
3046 | } else { | |
c96d145e | 3047 | if (rq1 < rq2) { |
1da177e4 | 3048 | spin_lock(&rq1->lock); |
5e710e37 | 3049 | spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
3050 | } else { |
3051 | spin_lock(&rq2->lock); | |
5e710e37 | 3052 | spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
3053 | } |
3054 | } | |
6e82a3be IM |
3055 | update_rq_clock(rq1); |
3056 | update_rq_clock(rq2); | |
1da177e4 LT |
3057 | } |
3058 | ||
3059 | /* | |
3060 | * double_rq_unlock - safely unlock two runqueues | |
3061 | * | |
3062 | * Note this does not restore interrupts like task_rq_unlock, | |
3063 | * you need to do so manually after calling. | |
3064 | */ | |
70b97a7f | 3065 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
3066 | __releases(rq1->lock) |
3067 | __releases(rq2->lock) | |
3068 | { | |
3069 | spin_unlock(&rq1->lock); | |
3070 | if (rq1 != rq2) | |
3071 | spin_unlock(&rq2->lock); | |
3072 | else | |
3073 | __release(rq2->lock); | |
3074 | } | |
3075 | ||
1da177e4 LT |
3076 | /* |
3077 | * If dest_cpu is allowed for this process, migrate the task to it. | |
3078 | * This is accomplished by forcing the cpu_allowed mask to only | |
41a2d6cf | 3079 | * allow dest_cpu, which will force the cpu onto dest_cpu. Then |
1da177e4 LT |
3080 | * the cpu_allowed mask is restored. |
3081 | */ | |
36c8b586 | 3082 | static void sched_migrate_task(struct task_struct *p, int dest_cpu) |
1da177e4 | 3083 | { |
70b97a7f | 3084 | struct migration_req req; |
1da177e4 | 3085 | unsigned long flags; |
70b97a7f | 3086 | struct rq *rq; |
1da177e4 LT |
3087 | |
3088 | rq = task_rq_lock(p, &flags); | |
96f874e2 | 3089 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) |
e761b772 | 3090 | || unlikely(!cpu_active(dest_cpu))) |
1da177e4 LT |
3091 | goto out; |
3092 | ||
3093 | /* force the process onto the specified CPU */ | |
3094 | if (migrate_task(p, dest_cpu, &req)) { | |
3095 | /* Need to wait for migration thread (might exit: take ref). */ | |
3096 | struct task_struct *mt = rq->migration_thread; | |
36c8b586 | 3097 | |
1da177e4 LT |
3098 | get_task_struct(mt); |
3099 | task_rq_unlock(rq, &flags); | |
3100 | wake_up_process(mt); | |
3101 | put_task_struct(mt); | |
3102 | wait_for_completion(&req.done); | |
36c8b586 | 3103 | |
1da177e4 LT |
3104 | return; |
3105 | } | |
3106 | out: | |
3107 | task_rq_unlock(rq, &flags); | |
3108 | } | |
3109 | ||
3110 | /* | |
476d139c NP |
3111 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3112 | * this point the task has the smallest effective memory and cache footprint. | |
1da177e4 LT |
3113 | */ |
3114 | void sched_exec(void) | |
3115 | { | |
1da177e4 | 3116 | int new_cpu, this_cpu = get_cpu(); |
476d139c | 3117 | new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); |
1da177e4 | 3118 | put_cpu(); |
476d139c NP |
3119 | if (new_cpu != this_cpu) |
3120 | sched_migrate_task(current, new_cpu); | |
1da177e4 LT |
3121 | } |
3122 | ||
3123 | /* | |
3124 | * pull_task - move a task from a remote runqueue to the local runqueue. | |
3125 | * Both runqueues must be locked. | |
3126 | */ | |
dd41f596 IM |
3127 | static void pull_task(struct rq *src_rq, struct task_struct *p, |
3128 | struct rq *this_rq, int this_cpu) | |
1da177e4 | 3129 | { |
2e1cb74a | 3130 | deactivate_task(src_rq, p, 0); |
1da177e4 | 3131 | set_task_cpu(p, this_cpu); |
dd41f596 | 3132 | activate_task(this_rq, p, 0); |
1da177e4 LT |
3133 | /* |
3134 | * Note that idle threads have a prio of MAX_PRIO, for this test | |
3135 | * to be always true for them. | |
3136 | */ | |
15afe09b | 3137 | check_preempt_curr(this_rq, p, 0); |
1da177e4 LT |
3138 | } |
3139 | ||
3140 | /* | |
3141 | * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? | |
3142 | */ | |
858119e1 | 3143 | static |
70b97a7f | 3144 | int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, |
d15bcfdb | 3145 | struct sched_domain *sd, enum cpu_idle_type idle, |
95cdf3b7 | 3146 | int *all_pinned) |
1da177e4 | 3147 | { |
708dc512 | 3148 | int tsk_cache_hot = 0; |
1da177e4 LT |
3149 | /* |
3150 | * We do not migrate tasks that are: | |
3151 | * 1) running (obviously), or | |
3152 | * 2) cannot be migrated to this CPU due to cpus_allowed, or | |
3153 | * 3) are cache-hot on their current CPU. | |
3154 | */ | |
96f874e2 | 3155 | if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { |
cc367732 | 3156 | schedstat_inc(p, se.nr_failed_migrations_affine); |
1da177e4 | 3157 | return 0; |
cc367732 | 3158 | } |
81026794 NP |
3159 | *all_pinned = 0; |
3160 | ||
cc367732 IM |
3161 | if (task_running(rq, p)) { |
3162 | schedstat_inc(p, se.nr_failed_migrations_running); | |
81026794 | 3163 | return 0; |
cc367732 | 3164 | } |
1da177e4 | 3165 | |
da84d961 IM |
3166 | /* |
3167 | * Aggressive migration if: | |
3168 | * 1) task is cache cold, or | |
3169 | * 2) too many balance attempts have failed. | |
3170 | */ | |
3171 | ||
708dc512 LH |
3172 | tsk_cache_hot = task_hot(p, rq->clock, sd); |
3173 | if (!tsk_cache_hot || | |
3174 | sd->nr_balance_failed > sd->cache_nice_tries) { | |
da84d961 | 3175 | #ifdef CONFIG_SCHEDSTATS |
708dc512 | 3176 | if (tsk_cache_hot) { |
da84d961 | 3177 | schedstat_inc(sd, lb_hot_gained[idle]); |
cc367732 IM |
3178 | schedstat_inc(p, se.nr_forced_migrations); |
3179 | } | |
da84d961 IM |
3180 | #endif |
3181 | return 1; | |
3182 | } | |
3183 | ||
708dc512 | 3184 | if (tsk_cache_hot) { |
cc367732 | 3185 | schedstat_inc(p, se.nr_failed_migrations_hot); |
da84d961 | 3186 | return 0; |
cc367732 | 3187 | } |
1da177e4 LT |
3188 | return 1; |
3189 | } | |
3190 | ||
e1d1484f PW |
3191 | static unsigned long |
3192 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3193 | unsigned long max_load_move, struct sched_domain *sd, | |
3194 | enum cpu_idle_type idle, int *all_pinned, | |
3195 | int *this_best_prio, struct rq_iterator *iterator) | |
1da177e4 | 3196 | { |
051c6764 | 3197 | int loops = 0, pulled = 0, pinned = 0; |
dd41f596 IM |
3198 | struct task_struct *p; |
3199 | long rem_load_move = max_load_move; | |
1da177e4 | 3200 | |
e1d1484f | 3201 | if (max_load_move == 0) |
1da177e4 LT |
3202 | goto out; |
3203 | ||
81026794 NP |
3204 | pinned = 1; |
3205 | ||
1da177e4 | 3206 | /* |
dd41f596 | 3207 | * Start the load-balancing iterator: |
1da177e4 | 3208 | */ |
dd41f596 IM |
3209 | p = iterator->start(iterator->arg); |
3210 | next: | |
b82d9fdd | 3211 | if (!p || loops++ > sysctl_sched_nr_migrate) |
1da177e4 | 3212 | goto out; |
051c6764 PZ |
3213 | |
3214 | if ((p->se.load.weight >> 1) > rem_load_move || | |
dd41f596 | 3215 | !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { |
dd41f596 IM |
3216 | p = iterator->next(iterator->arg); |
3217 | goto next; | |
1da177e4 LT |
3218 | } |
3219 | ||
dd41f596 | 3220 | pull_task(busiest, p, this_rq, this_cpu); |
1da177e4 | 3221 | pulled++; |
dd41f596 | 3222 | rem_load_move -= p->se.load.weight; |
1da177e4 | 3223 | |
7e96fa58 GH |
3224 | #ifdef CONFIG_PREEMPT |
3225 | /* | |
3226 | * NEWIDLE balancing is a source of latency, so preemptible kernels | |
3227 | * will stop after the first task is pulled to minimize the critical | |
3228 | * section. | |
3229 | */ | |
3230 | if (idle == CPU_NEWLY_IDLE) | |
3231 | goto out; | |
3232 | #endif | |
3233 | ||
2dd73a4f | 3234 | /* |
b82d9fdd | 3235 | * We only want to steal up to the prescribed amount of weighted load. |
2dd73a4f | 3236 | */ |
e1d1484f | 3237 | if (rem_load_move > 0) { |
a4ac01c3 PW |
3238 | if (p->prio < *this_best_prio) |
3239 | *this_best_prio = p->prio; | |
dd41f596 IM |
3240 | p = iterator->next(iterator->arg); |
3241 | goto next; | |
1da177e4 LT |
3242 | } |
3243 | out: | |
3244 | /* | |
e1d1484f | 3245 | * Right now, this is one of only two places pull_task() is called, |
1da177e4 LT |
3246 | * so we can safely collect pull_task() stats here rather than |
3247 | * inside pull_task(). | |
3248 | */ | |
3249 | schedstat_add(sd, lb_gained[idle], pulled); | |
81026794 NP |
3250 | |
3251 | if (all_pinned) | |
3252 | *all_pinned = pinned; | |
e1d1484f PW |
3253 | |
3254 | return max_load_move - rem_load_move; | |
1da177e4 LT |
3255 | } |
3256 | ||
dd41f596 | 3257 | /* |
43010659 PW |
3258 | * move_tasks tries to move up to max_load_move weighted load from busiest to |
3259 | * this_rq, as part of a balancing operation within domain "sd". | |
3260 | * Returns 1 if successful and 0 otherwise. | |
dd41f596 IM |
3261 | * |
3262 | * Called with both runqueues locked. | |
3263 | */ | |
3264 | static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
43010659 | 3265 | unsigned long max_load_move, |
dd41f596 IM |
3266 | struct sched_domain *sd, enum cpu_idle_type idle, |
3267 | int *all_pinned) | |
3268 | { | |
5522d5d5 | 3269 | const struct sched_class *class = sched_class_highest; |
43010659 | 3270 | unsigned long total_load_moved = 0; |
a4ac01c3 | 3271 | int this_best_prio = this_rq->curr->prio; |
dd41f596 IM |
3272 | |
3273 | do { | |
43010659 PW |
3274 | total_load_moved += |
3275 | class->load_balance(this_rq, this_cpu, busiest, | |
e1d1484f | 3276 | max_load_move - total_load_moved, |
a4ac01c3 | 3277 | sd, idle, all_pinned, &this_best_prio); |
dd41f596 | 3278 | class = class->next; |
c4acb2c0 | 3279 | |
7e96fa58 GH |
3280 | #ifdef CONFIG_PREEMPT |
3281 | /* | |
3282 | * NEWIDLE balancing is a source of latency, so preemptible | |
3283 | * kernels will stop after the first task is pulled to minimize | |
3284 | * the critical section. | |
3285 | */ | |
c4acb2c0 GH |
3286 | if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) |
3287 | break; | |
7e96fa58 | 3288 | #endif |
43010659 | 3289 | } while (class && max_load_move > total_load_moved); |
dd41f596 | 3290 | |
43010659 PW |
3291 | return total_load_moved > 0; |
3292 | } | |
3293 | ||
e1d1484f PW |
3294 | static int |
3295 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3296 | struct sched_domain *sd, enum cpu_idle_type idle, | |
3297 | struct rq_iterator *iterator) | |
3298 | { | |
3299 | struct task_struct *p = iterator->start(iterator->arg); | |
3300 | int pinned = 0; | |
3301 | ||
3302 | while (p) { | |
3303 | if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { | |
3304 | pull_task(busiest, p, this_rq, this_cpu); | |
3305 | /* | |
3306 | * Right now, this is only the second place pull_task() | |
3307 | * is called, so we can safely collect pull_task() | |
3308 | * stats here rather than inside pull_task(). | |
3309 | */ | |
3310 | schedstat_inc(sd, lb_gained[idle]); | |
3311 | ||
3312 | return 1; | |
3313 | } | |
3314 | p = iterator->next(iterator->arg); | |
3315 | } | |
3316 | ||
3317 | return 0; | |
3318 | } | |
3319 | ||
43010659 PW |
3320 | /* |
3321 | * move_one_task tries to move exactly one task from busiest to this_rq, as | |
3322 | * part of active balancing operations within "domain". | |
3323 | * Returns 1 if successful and 0 otherwise. | |
3324 | * | |
3325 | * Called with both runqueues locked. | |
3326 | */ | |
3327 | static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3328 | struct sched_domain *sd, enum cpu_idle_type idle) | |
3329 | { | |
5522d5d5 | 3330 | const struct sched_class *class; |
43010659 | 3331 | |
cde7e5ca | 3332 | for_each_class(class) { |
e1d1484f | 3333 | if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) |
43010659 | 3334 | return 1; |
cde7e5ca | 3335 | } |
43010659 PW |
3336 | |
3337 | return 0; | |
dd41f596 | 3338 | } |
67bb6c03 | 3339 | /********** Helpers for find_busiest_group ************************/ |
1da177e4 | 3340 | /* |
222d656d GS |
3341 | * sd_lb_stats - Structure to store the statistics of a sched_domain |
3342 | * during load balancing. | |
1da177e4 | 3343 | */ |
222d656d GS |
3344 | struct sd_lb_stats { |
3345 | struct sched_group *busiest; /* Busiest group in this sd */ | |
3346 | struct sched_group *this; /* Local group in this sd */ | |
3347 | unsigned long total_load; /* Total load of all groups in sd */ | |
3348 | unsigned long total_pwr; /* Total power of all groups in sd */ | |
3349 | unsigned long avg_load; /* Average load across all groups in sd */ | |
3350 | ||
3351 | /** Statistics of this group */ | |
3352 | unsigned long this_load; | |
3353 | unsigned long this_load_per_task; | |
3354 | unsigned long this_nr_running; | |
3355 | ||
3356 | /* Statistics of the busiest group */ | |
3357 | unsigned long max_load; | |
3358 | unsigned long busiest_load_per_task; | |
3359 | unsigned long busiest_nr_running; | |
3360 | ||
3361 | int group_imb; /* Is there imbalance in this sd */ | |
5c45bf27 | 3362 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
222d656d GS |
3363 | int power_savings_balance; /* Is powersave balance needed for this sd */ |
3364 | struct sched_group *group_min; /* Least loaded group in sd */ | |
3365 | struct sched_group *group_leader; /* Group which relieves group_min */ | |
3366 | unsigned long min_load_per_task; /* load_per_task in group_min */ | |
3367 | unsigned long leader_nr_running; /* Nr running of group_leader */ | |
3368 | unsigned long min_nr_running; /* Nr running of group_min */ | |
5c45bf27 | 3369 | #endif |
222d656d | 3370 | }; |
1da177e4 | 3371 | |
d5ac537e | 3372 | /* |
381be78f GS |
3373 | * sg_lb_stats - stats of a sched_group required for load_balancing |
3374 | */ | |
3375 | struct sg_lb_stats { | |
3376 | unsigned long avg_load; /*Avg load across the CPUs of the group */ | |
3377 | unsigned long group_load; /* Total load over the CPUs of the group */ | |
3378 | unsigned long sum_nr_running; /* Nr tasks running in the group */ | |
3379 | unsigned long sum_weighted_load; /* Weighted load of group's tasks */ | |
3380 | unsigned long group_capacity; | |
3381 | int group_imb; /* Is there an imbalance in the group ? */ | |
3382 | }; | |
408ed066 | 3383 | |
67bb6c03 GS |
3384 | /** |
3385 | * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. | |
3386 | * @group: The group whose first cpu is to be returned. | |
3387 | */ | |
3388 | static inline unsigned int group_first_cpu(struct sched_group *group) | |
3389 | { | |
3390 | return cpumask_first(sched_group_cpus(group)); | |
3391 | } | |
3392 | ||
3393 | /** | |
3394 | * get_sd_load_idx - Obtain the load index for a given sched domain. | |
3395 | * @sd: The sched_domain whose load_idx is to be obtained. | |
3396 | * @idle: The Idle status of the CPU for whose sd load_icx is obtained. | |
3397 | */ | |
3398 | static inline int get_sd_load_idx(struct sched_domain *sd, | |
3399 | enum cpu_idle_type idle) | |
3400 | { | |
3401 | int load_idx; | |
3402 | ||
3403 | switch (idle) { | |
3404 | case CPU_NOT_IDLE: | |
7897986b | 3405 | load_idx = sd->busy_idx; |
67bb6c03 GS |
3406 | break; |
3407 | ||
3408 | case CPU_NEWLY_IDLE: | |
7897986b | 3409 | load_idx = sd->newidle_idx; |
67bb6c03 GS |
3410 | break; |
3411 | default: | |
7897986b | 3412 | load_idx = sd->idle_idx; |
67bb6c03 GS |
3413 | break; |
3414 | } | |
1da177e4 | 3415 | |
67bb6c03 GS |
3416 | return load_idx; |
3417 | } | |
1da177e4 | 3418 | |
1da177e4 | 3419 | |
c071df18 GS |
3420 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
3421 | /** | |
3422 | * init_sd_power_savings_stats - Initialize power savings statistics for | |
3423 | * the given sched_domain, during load balancing. | |
3424 | * | |
3425 | * @sd: Sched domain whose power-savings statistics are to be initialized. | |
3426 | * @sds: Variable containing the statistics for sd. | |
3427 | * @idle: Idle status of the CPU at which we're performing load-balancing. | |
3428 | */ | |
3429 | static inline void init_sd_power_savings_stats(struct sched_domain *sd, | |
3430 | struct sd_lb_stats *sds, enum cpu_idle_type idle) | |
3431 | { | |
3432 | /* | |
3433 | * Busy processors will not participate in power savings | |
3434 | * balance. | |
3435 | */ | |
3436 | if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) | |
3437 | sds->power_savings_balance = 0; | |
3438 | else { | |
3439 | sds->power_savings_balance = 1; | |
3440 | sds->min_nr_running = ULONG_MAX; | |
3441 | sds->leader_nr_running = 0; | |
3442 | } | |
3443 | } | |
783609c6 | 3444 | |
c071df18 GS |
3445 | /** |
3446 | * update_sd_power_savings_stats - Update the power saving stats for a | |
3447 | * sched_domain while performing load balancing. | |
3448 | * | |
3449 | * @group: sched_group belonging to the sched_domain under consideration. | |
3450 | * @sds: Variable containing the statistics of the sched_domain | |
3451 | * @local_group: Does group contain the CPU for which we're performing | |
3452 | * load balancing ? | |
3453 | * @sgs: Variable containing the statistics of the group. | |
3454 | */ | |
3455 | static inline void update_sd_power_savings_stats(struct sched_group *group, | |
3456 | struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) | |
3457 | { | |
408ed066 | 3458 | |
c071df18 GS |
3459 | if (!sds->power_savings_balance) |
3460 | return; | |
1da177e4 | 3461 | |
c071df18 GS |
3462 | /* |
3463 | * If the local group is idle or completely loaded | |
3464 | * no need to do power savings balance at this domain | |
3465 | */ | |
3466 | if (local_group && (sds->this_nr_running >= sgs->group_capacity || | |
3467 | !sds->this_nr_running)) | |
3468 | sds->power_savings_balance = 0; | |
2dd73a4f | 3469 | |
c071df18 GS |
3470 | /* |
3471 | * If a group is already running at full capacity or idle, | |
3472 | * don't include that group in power savings calculations | |
3473 | */ | |
3474 | if (!sds->power_savings_balance || | |
3475 | sgs->sum_nr_running >= sgs->group_capacity || | |
3476 | !sgs->sum_nr_running) | |
3477 | return; | |
5969fe06 | 3478 | |
c071df18 GS |
3479 | /* |
3480 | * Calculate the group which has the least non-idle load. | |
3481 | * This is the group from where we need to pick up the load | |
3482 | * for saving power | |
3483 | */ | |
3484 | if ((sgs->sum_nr_running < sds->min_nr_running) || | |
3485 | (sgs->sum_nr_running == sds->min_nr_running && | |
3486 | group_first_cpu(group) > group_first_cpu(sds->group_min))) { | |
3487 | sds->group_min = group; | |
3488 | sds->min_nr_running = sgs->sum_nr_running; | |
3489 | sds->min_load_per_task = sgs->sum_weighted_load / | |
3490 | sgs->sum_nr_running; | |
3491 | } | |
783609c6 | 3492 | |
c071df18 GS |
3493 | /* |
3494 | * Calculate the group which is almost near its | |
3495 | * capacity but still has some space to pick up some load | |
3496 | * from other group and save more power | |
3497 | */ | |
d899a789 | 3498 | if (sgs->sum_nr_running + 1 > sgs->group_capacity) |
c071df18 | 3499 | return; |
1da177e4 | 3500 | |
c071df18 GS |
3501 | if (sgs->sum_nr_running > sds->leader_nr_running || |
3502 | (sgs->sum_nr_running == sds->leader_nr_running && | |
3503 | group_first_cpu(group) < group_first_cpu(sds->group_leader))) { | |
3504 | sds->group_leader = group; | |
3505 | sds->leader_nr_running = sgs->sum_nr_running; | |
3506 | } | |
3507 | } | |
408ed066 | 3508 | |
c071df18 | 3509 | /** |
d5ac537e | 3510 | * check_power_save_busiest_group - see if there is potential for some power-savings balance |
c071df18 GS |
3511 | * @sds: Variable containing the statistics of the sched_domain |
3512 | * under consideration. | |
3513 | * @this_cpu: Cpu at which we're currently performing load-balancing. | |
3514 | * @imbalance: Variable to store the imbalance. | |
3515 | * | |
d5ac537e RD |
3516 | * Description: |
3517 | * Check if we have potential to perform some power-savings balance. | |
3518 | * If yes, set the busiest group to be the least loaded group in the | |
3519 | * sched_domain, so that it's CPUs can be put to idle. | |
3520 | * | |
c071df18 GS |
3521 | * Returns 1 if there is potential to perform power-savings balance. |
3522 | * Else returns 0. | |
3523 | */ | |
3524 | static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, | |
3525 | int this_cpu, unsigned long *imbalance) | |
3526 | { | |
3527 | if (!sds->power_savings_balance) | |
3528 | return 0; | |
1da177e4 | 3529 | |
c071df18 GS |
3530 | if (sds->this != sds->group_leader || |
3531 | sds->group_leader == sds->group_min) | |
3532 | return 0; | |
783609c6 | 3533 | |
c071df18 GS |
3534 | *imbalance = sds->min_load_per_task; |
3535 | sds->busiest = sds->group_min; | |
1da177e4 | 3536 | |
c071df18 GS |
3537 | if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) { |
3538 | cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu = | |
3539 | group_first_cpu(sds->group_leader); | |
3540 | } | |
3541 | ||
3542 | return 1; | |
1da177e4 | 3543 | |
c071df18 GS |
3544 | } |
3545 | #else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | |
3546 | static inline void init_sd_power_savings_stats(struct sched_domain *sd, | |
3547 | struct sd_lb_stats *sds, enum cpu_idle_type idle) | |
3548 | { | |
3549 | return; | |
3550 | } | |
408ed066 | 3551 | |
c071df18 GS |
3552 | static inline void update_sd_power_savings_stats(struct sched_group *group, |
3553 | struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) | |
3554 | { | |
3555 | return; | |
3556 | } | |
3557 | ||
3558 | static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, | |
3559 | int this_cpu, unsigned long *imbalance) | |
3560 | { | |
3561 | return 0; | |
3562 | } | |
3563 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | |
3564 | ||
e9e9250b | 3565 | unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) |
ab29230e PZ |
3566 | { |
3567 | unsigned long weight = cpumask_weight(sched_domain_span(sd)); | |
3568 | unsigned long smt_gain = sd->smt_gain; | |
3569 | ||
3570 | smt_gain /= weight; | |
3571 | ||
3572 | return smt_gain; | |
3573 | } | |
3574 | ||
e9e9250b PZ |
3575 | unsigned long scale_rt_power(int cpu) |
3576 | { | |
3577 | struct rq *rq = cpu_rq(cpu); | |
3578 | u64 total, available; | |
3579 | ||
3580 | sched_avg_update(rq); | |
3581 | ||
3582 | total = sched_avg_period() + (rq->clock - rq->age_stamp); | |
3583 | available = total - rq->rt_avg; | |
3584 | ||
3585 | if (unlikely((s64)total < SCHED_LOAD_SCALE)) | |
3586 | total = SCHED_LOAD_SCALE; | |
3587 | ||
3588 | total >>= SCHED_LOAD_SHIFT; | |
3589 | ||
3590 | return div_u64(available, total); | |
3591 | } | |
3592 | ||
ab29230e PZ |
3593 | static void update_cpu_power(struct sched_domain *sd, int cpu) |
3594 | { | |
3595 | unsigned long weight = cpumask_weight(sched_domain_span(sd)); | |
3596 | unsigned long power = SCHED_LOAD_SCALE; | |
3597 | struct sched_group *sdg = sd->groups; | |
ab29230e PZ |
3598 | |
3599 | /* here we could scale based on cpufreq */ | |
3600 | ||
3601 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { | |
e9e9250b | 3602 | power *= arch_scale_smt_power(sd, cpu); |
ab29230e PZ |
3603 | power >>= SCHED_LOAD_SHIFT; |
3604 | } | |
3605 | ||
e9e9250b PZ |
3606 | power *= scale_rt_power(cpu); |
3607 | power >>= SCHED_LOAD_SHIFT; | |
3608 | ||
3609 | if (!power) | |
3610 | power = 1; | |
ab29230e | 3611 | |
18a3885f | 3612 | sdg->cpu_power = power; |
ab29230e PZ |
3613 | } |
3614 | ||
3615 | static void update_group_power(struct sched_domain *sd, int cpu) | |
cc9fba7d PZ |
3616 | { |
3617 | struct sched_domain *child = sd->child; | |
3618 | struct sched_group *group, *sdg = sd->groups; | |
d7ea17a7 | 3619 | unsigned long power; |
cc9fba7d PZ |
3620 | |
3621 | if (!child) { | |
ab29230e | 3622 | update_cpu_power(sd, cpu); |
cc9fba7d PZ |
3623 | return; |
3624 | } | |
3625 | ||
d7ea17a7 | 3626 | power = 0; |
cc9fba7d PZ |
3627 | |
3628 | group = child->groups; | |
3629 | do { | |
d7ea17a7 | 3630 | power += group->cpu_power; |
cc9fba7d PZ |
3631 | group = group->next; |
3632 | } while (group != child->groups); | |
d7ea17a7 IM |
3633 | |
3634 | sdg->cpu_power = power; | |
cc9fba7d | 3635 | } |
c071df18 | 3636 | |
1f8c553d GS |
3637 | /** |
3638 | * update_sg_lb_stats - Update sched_group's statistics for load balancing. | |
3639 | * @group: sched_group whose statistics are to be updated. | |
3640 | * @this_cpu: Cpu for which load balance is currently performed. | |
3641 | * @idle: Idle status of this_cpu | |
3642 | * @load_idx: Load index of sched_domain of this_cpu for load calc. | |
3643 | * @sd_idle: Idle status of the sched_domain containing group. | |
3644 | * @local_group: Does group contain this_cpu. | |
3645 | * @cpus: Set of cpus considered for load balancing. | |
3646 | * @balance: Should we balance. | |
3647 | * @sgs: variable to hold the statistics for this group. | |
3648 | */ | |
cc9fba7d PZ |
3649 | static inline void update_sg_lb_stats(struct sched_domain *sd, |
3650 | struct sched_group *group, int this_cpu, | |
1f8c553d GS |
3651 | enum cpu_idle_type idle, int load_idx, int *sd_idle, |
3652 | int local_group, const struct cpumask *cpus, | |
3653 | int *balance, struct sg_lb_stats *sgs) | |
3654 | { | |
3655 | unsigned long load, max_cpu_load, min_cpu_load; | |
3656 | int i; | |
3657 | unsigned int balance_cpu = -1, first_idle_cpu = 0; | |
3658 | unsigned long sum_avg_load_per_task; | |
3659 | unsigned long avg_load_per_task; | |
3660 | ||
cc9fba7d | 3661 | if (local_group) { |
1f8c553d | 3662 | balance_cpu = group_first_cpu(group); |
cc9fba7d | 3663 | if (balance_cpu == this_cpu) |
ab29230e | 3664 | update_group_power(sd, this_cpu); |
cc9fba7d | 3665 | } |
1f8c553d GS |
3666 | |
3667 | /* Tally up the load of all CPUs in the group */ | |
3668 | sum_avg_load_per_task = avg_load_per_task = 0; | |
3669 | max_cpu_load = 0; | |
3670 | min_cpu_load = ~0UL; | |
408ed066 | 3671 | |
1f8c553d GS |
3672 | for_each_cpu_and(i, sched_group_cpus(group), cpus) { |
3673 | struct rq *rq = cpu_rq(i); | |
908a7c1b | 3674 | |
1f8c553d GS |
3675 | if (*sd_idle && rq->nr_running) |
3676 | *sd_idle = 0; | |
5c45bf27 | 3677 | |
1f8c553d | 3678 | /* Bias balancing toward cpus of our domain */ |
1da177e4 | 3679 | if (local_group) { |
1f8c553d GS |
3680 | if (idle_cpu(i) && !first_idle_cpu) { |
3681 | first_idle_cpu = 1; | |
3682 | balance_cpu = i; | |
3683 | } | |
3684 | ||
3685 | load = target_load(i, load_idx); | |
3686 | } else { | |
3687 | load = source_load(i, load_idx); | |
3688 | if (load > max_cpu_load) | |
3689 | max_cpu_load = load; | |
3690 | if (min_cpu_load > load) | |
3691 | min_cpu_load = load; | |
1da177e4 | 3692 | } |
5c45bf27 | 3693 | |
1f8c553d GS |
3694 | sgs->group_load += load; |
3695 | sgs->sum_nr_running += rq->nr_running; | |
3696 | sgs->sum_weighted_load += weighted_cpuload(i); | |
5c45bf27 | 3697 | |
1f8c553d GS |
3698 | sum_avg_load_per_task += cpu_avg_load_per_task(i); |
3699 | } | |
5c45bf27 | 3700 | |
1f8c553d GS |
3701 | /* |
3702 | * First idle cpu or the first cpu(busiest) in this sched group | |
3703 | * is eligible for doing load balancing at this and above | |
3704 | * domains. In the newly idle case, we will allow all the cpu's | |
3705 | * to do the newly idle load balance. | |
3706 | */ | |
3707 | if (idle != CPU_NEWLY_IDLE && local_group && | |
3708 | balance_cpu != this_cpu && balance) { | |
3709 | *balance = 0; | |
3710 | return; | |
3711 | } | |
5c45bf27 | 3712 | |
1f8c553d | 3713 | /* Adjust by relative CPU power of the group */ |
18a3885f | 3714 | sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power; |
5c45bf27 | 3715 | |
1f8c553d GS |
3716 | |
3717 | /* | |
3718 | * Consider the group unbalanced when the imbalance is larger | |
3719 | * than the average weight of two tasks. | |
3720 | * | |
3721 | * APZ: with cgroup the avg task weight can vary wildly and | |
3722 | * might not be a suitable number - should we keep a | |
3723 | * normalized nr_running number somewhere that negates | |
3724 | * the hierarchy? | |
3725 | */ | |
18a3885f PZ |
3726 | avg_load_per_task = (sum_avg_load_per_task * SCHED_LOAD_SCALE) / |
3727 | group->cpu_power; | |
1f8c553d GS |
3728 | |
3729 | if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) | |
3730 | sgs->group_imb = 1; | |
3731 | ||
bdb94aa5 | 3732 | sgs->group_capacity = |
18a3885f | 3733 | DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE); |
1f8c553d | 3734 | } |
dd41f596 | 3735 | |
37abe198 GS |
3736 | /** |
3737 | * update_sd_lb_stats - Update sched_group's statistics for load balancing. | |
3738 | * @sd: sched_domain whose statistics are to be updated. | |
3739 | * @this_cpu: Cpu for which load balance is currently performed. | |
3740 | * @idle: Idle status of this_cpu | |
3741 | * @sd_idle: Idle status of the sched_domain containing group. | |
3742 | * @cpus: Set of cpus considered for load balancing. | |
3743 | * @balance: Should we balance. | |
3744 | * @sds: variable to hold the statistics for this sched_domain. | |
1da177e4 | 3745 | */ |
37abe198 GS |
3746 | static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, |
3747 | enum cpu_idle_type idle, int *sd_idle, | |
3748 | const struct cpumask *cpus, int *balance, | |
3749 | struct sd_lb_stats *sds) | |
1da177e4 | 3750 | { |
b5d978e0 | 3751 | struct sched_domain *child = sd->child; |
222d656d | 3752 | struct sched_group *group = sd->groups; |
37abe198 | 3753 | struct sg_lb_stats sgs; |
b5d978e0 PZ |
3754 | int load_idx, prefer_sibling = 0; |
3755 | ||
3756 | if (child && child->flags & SD_PREFER_SIBLING) | |
3757 | prefer_sibling = 1; | |
222d656d | 3758 | |
c071df18 | 3759 | init_sd_power_savings_stats(sd, sds, idle); |
67bb6c03 | 3760 | load_idx = get_sd_load_idx(sd, idle); |
1da177e4 LT |
3761 | |
3762 | do { | |
1da177e4 | 3763 | int local_group; |
1da177e4 | 3764 | |
758b2cdc RR |
3765 | local_group = cpumask_test_cpu(this_cpu, |
3766 | sched_group_cpus(group)); | |
381be78f | 3767 | memset(&sgs, 0, sizeof(sgs)); |
cc9fba7d | 3768 | update_sg_lb_stats(sd, group, this_cpu, idle, load_idx, sd_idle, |
1f8c553d | 3769 | local_group, cpus, balance, &sgs); |
1da177e4 | 3770 | |
37abe198 GS |
3771 | if (local_group && balance && !(*balance)) |
3772 | return; | |
783609c6 | 3773 | |
37abe198 | 3774 | sds->total_load += sgs.group_load; |
18a3885f | 3775 | sds->total_pwr += group->cpu_power; |
1da177e4 | 3776 | |
b5d978e0 PZ |
3777 | /* |
3778 | * In case the child domain prefers tasks go to siblings | |
3779 | * first, lower the group capacity to one so that we'll try | |
3780 | * and move all the excess tasks away. | |
3781 | */ | |
3782 | if (prefer_sibling) | |
bdb94aa5 | 3783 | sgs.group_capacity = min(sgs.group_capacity, 1UL); |
1da177e4 | 3784 | |
1da177e4 | 3785 | if (local_group) { |
37abe198 GS |
3786 | sds->this_load = sgs.avg_load; |
3787 | sds->this = group; | |
3788 | sds->this_nr_running = sgs.sum_nr_running; | |
3789 | sds->this_load_per_task = sgs.sum_weighted_load; | |
3790 | } else if (sgs.avg_load > sds->max_load && | |
381be78f GS |
3791 | (sgs.sum_nr_running > sgs.group_capacity || |
3792 | sgs.group_imb)) { | |
37abe198 GS |
3793 | sds->max_load = sgs.avg_load; |
3794 | sds->busiest = group; | |
3795 | sds->busiest_nr_running = sgs.sum_nr_running; | |
3796 | sds->busiest_load_per_task = sgs.sum_weighted_load; | |
3797 | sds->group_imb = sgs.group_imb; | |
48f24c4d | 3798 | } |
5c45bf27 | 3799 | |
c071df18 | 3800 | update_sd_power_savings_stats(group, sds, local_group, &sgs); |
1da177e4 LT |
3801 | group = group->next; |
3802 | } while (group != sd->groups); | |
37abe198 | 3803 | } |
1da177e4 | 3804 | |
2e6f44ae GS |
3805 | /** |
3806 | * fix_small_imbalance - Calculate the minor imbalance that exists | |
dbc523a3 GS |
3807 | * amongst the groups of a sched_domain, during |
3808 | * load balancing. | |
2e6f44ae GS |
3809 | * @sds: Statistics of the sched_domain whose imbalance is to be calculated. |
3810 | * @this_cpu: The cpu at whose sched_domain we're performing load-balance. | |
3811 | * @imbalance: Variable to store the imbalance. | |
3812 | */ | |
3813 | static inline void fix_small_imbalance(struct sd_lb_stats *sds, | |
3814 | int this_cpu, unsigned long *imbalance) | |
3815 | { | |
3816 | unsigned long tmp, pwr_now = 0, pwr_move = 0; | |
3817 | unsigned int imbn = 2; | |
3818 | ||
3819 | if (sds->this_nr_running) { | |
3820 | sds->this_load_per_task /= sds->this_nr_running; | |
3821 | if (sds->busiest_load_per_task > | |
3822 | sds->this_load_per_task) | |
3823 | imbn = 1; | |
3824 | } else | |
3825 | sds->this_load_per_task = | |
3826 | cpu_avg_load_per_task(this_cpu); | |
1da177e4 | 3827 | |
2e6f44ae GS |
3828 | if (sds->max_load - sds->this_load + sds->busiest_load_per_task >= |
3829 | sds->busiest_load_per_task * imbn) { | |
3830 | *imbalance = sds->busiest_load_per_task; | |
3831 | return; | |
3832 | } | |
908a7c1b | 3833 | |
1da177e4 | 3834 | /* |
2e6f44ae GS |
3835 | * OK, we don't have enough imbalance to justify moving tasks, |
3836 | * however we may be able to increase total CPU power used by | |
3837 | * moving them. | |
1da177e4 | 3838 | */ |
2dd73a4f | 3839 | |
18a3885f | 3840 | pwr_now += sds->busiest->cpu_power * |
2e6f44ae | 3841 | min(sds->busiest_load_per_task, sds->max_load); |
18a3885f | 3842 | pwr_now += sds->this->cpu_power * |
2e6f44ae GS |
3843 | min(sds->this_load_per_task, sds->this_load); |
3844 | pwr_now /= SCHED_LOAD_SCALE; | |
3845 | ||
3846 | /* Amount of load we'd subtract */ | |
18a3885f PZ |
3847 | tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) / |
3848 | sds->busiest->cpu_power; | |
2e6f44ae | 3849 | if (sds->max_load > tmp) |
18a3885f | 3850 | pwr_move += sds->busiest->cpu_power * |
2e6f44ae GS |
3851 | min(sds->busiest_load_per_task, sds->max_load - tmp); |
3852 | ||
3853 | /* Amount of load we'd add */ | |
18a3885f | 3854 | if (sds->max_load * sds->busiest->cpu_power < |
2e6f44ae | 3855 | sds->busiest_load_per_task * SCHED_LOAD_SCALE) |
18a3885f PZ |
3856 | tmp = (sds->max_load * sds->busiest->cpu_power) / |
3857 | sds->this->cpu_power; | |
2e6f44ae | 3858 | else |
18a3885f PZ |
3859 | tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) / |
3860 | sds->this->cpu_power; | |
3861 | pwr_move += sds->this->cpu_power * | |
2e6f44ae GS |
3862 | min(sds->this_load_per_task, sds->this_load + tmp); |
3863 | pwr_move /= SCHED_LOAD_SCALE; | |
3864 | ||
3865 | /* Move if we gain throughput */ | |
3866 | if (pwr_move > pwr_now) | |
3867 | *imbalance = sds->busiest_load_per_task; | |
3868 | } | |
dbc523a3 GS |
3869 | |
3870 | /** | |
3871 | * calculate_imbalance - Calculate the amount of imbalance present within the | |
3872 | * groups of a given sched_domain during load balance. | |
3873 | * @sds: statistics of the sched_domain whose imbalance is to be calculated. | |
3874 | * @this_cpu: Cpu for which currently load balance is being performed. | |
3875 | * @imbalance: The variable to store the imbalance. | |
3876 | */ | |
3877 | static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, | |
3878 | unsigned long *imbalance) | |
3879 | { | |
3880 | unsigned long max_pull; | |
2dd73a4f PW |
3881 | /* |
3882 | * In the presence of smp nice balancing, certain scenarios can have | |
3883 | * max load less than avg load(as we skip the groups at or below | |
3884 | * its cpu_power, while calculating max_load..) | |
3885 | */ | |
dbc523a3 | 3886 | if (sds->max_load < sds->avg_load) { |
2dd73a4f | 3887 | *imbalance = 0; |
dbc523a3 | 3888 | return fix_small_imbalance(sds, this_cpu, imbalance); |
2dd73a4f | 3889 | } |
0c117f1b SS |
3890 | |
3891 | /* Don't want to pull so many tasks that a group would go idle */ | |
dbc523a3 GS |
3892 | max_pull = min(sds->max_load - sds->avg_load, |
3893 | sds->max_load - sds->busiest_load_per_task); | |
0c117f1b | 3894 | |
1da177e4 | 3895 | /* How much load to actually move to equalise the imbalance */ |
18a3885f PZ |
3896 | *imbalance = min(max_pull * sds->busiest->cpu_power, |
3897 | (sds->avg_load - sds->this_load) * sds->this->cpu_power) | |
1da177e4 LT |
3898 | / SCHED_LOAD_SCALE; |
3899 | ||
2dd73a4f PW |
3900 | /* |
3901 | * if *imbalance is less than the average load per runnable task | |
3902 | * there is no gaurantee that any tasks will be moved so we'll have | |
3903 | * a think about bumping its value to force at least one task to be | |
3904 | * moved | |
3905 | */ | |
dbc523a3 GS |
3906 | if (*imbalance < sds->busiest_load_per_task) |
3907 | return fix_small_imbalance(sds, this_cpu, imbalance); | |
1da177e4 | 3908 | |
dbc523a3 | 3909 | } |
37abe198 | 3910 | /******* find_busiest_group() helpers end here *********************/ |
1da177e4 | 3911 | |
b7bb4c9b GS |
3912 | /** |
3913 | * find_busiest_group - Returns the busiest group within the sched_domain | |
3914 | * if there is an imbalance. If there isn't an imbalance, and | |
3915 | * the user has opted for power-savings, it returns a group whose | |
3916 | * CPUs can be put to idle by rebalancing those tasks elsewhere, if | |
3917 | * such a group exists. | |
3918 | * | |
3919 | * Also calculates the amount of weighted load which should be moved | |
3920 | * to restore balance. | |
3921 | * | |
3922 | * @sd: The sched_domain whose busiest group is to be returned. | |
3923 | * @this_cpu: The cpu for which load balancing is currently being performed. | |
3924 | * @imbalance: Variable which stores amount of weighted load which should | |
3925 | * be moved to restore balance/put a group to idle. | |
3926 | * @idle: The idle status of this_cpu. | |
3927 | * @sd_idle: The idleness of sd | |
3928 | * @cpus: The set of CPUs under consideration for load-balancing. | |
3929 | * @balance: Pointer to a variable indicating if this_cpu | |
3930 | * is the appropriate cpu to perform load balancing at this_level. | |
3931 | * | |
3932 | * Returns: - the busiest group if imbalance exists. | |
3933 | * - If no imbalance and user has opted for power-savings balance, | |
3934 | * return the least loaded group whose CPUs can be | |
3935 | * put to idle by rebalancing its tasks onto our group. | |
37abe198 GS |
3936 | */ |
3937 | static struct sched_group * | |
3938 | find_busiest_group(struct sched_domain *sd, int this_cpu, | |
3939 | unsigned long *imbalance, enum cpu_idle_type idle, | |
3940 | int *sd_idle, const struct cpumask *cpus, int *balance) | |
3941 | { | |
3942 | struct sd_lb_stats sds; | |
1da177e4 | 3943 | |
37abe198 | 3944 | memset(&sds, 0, sizeof(sds)); |
1da177e4 | 3945 | |
37abe198 GS |
3946 | /* |
3947 | * Compute the various statistics relavent for load balancing at | |
3948 | * this level. | |
3949 | */ | |
3950 | update_sd_lb_stats(sd, this_cpu, idle, sd_idle, cpus, | |
3951 | balance, &sds); | |
3952 | ||
b7bb4c9b GS |
3953 | /* Cases where imbalance does not exist from POV of this_cpu */ |
3954 | /* 1) this_cpu is not the appropriate cpu to perform load balancing | |
3955 | * at this level. | |
3956 | * 2) There is no busy sibling group to pull from. | |
3957 | * 3) This group is the busiest group. | |
3958 | * 4) This group is more busy than the avg busieness at this | |
3959 | * sched_domain. | |
3960 | * 5) The imbalance is within the specified limit. | |
3961 | * 6) Any rebalance would lead to ping-pong | |
3962 | */ | |
37abe198 GS |
3963 | if (balance && !(*balance)) |
3964 | goto ret; | |
1da177e4 | 3965 | |
b7bb4c9b GS |
3966 | if (!sds.busiest || sds.busiest_nr_running == 0) |
3967 | goto out_balanced; | |
1da177e4 | 3968 | |
b7bb4c9b | 3969 | if (sds.this_load >= sds.max_load) |
1da177e4 | 3970 | goto out_balanced; |
1da177e4 | 3971 | |
222d656d | 3972 | sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr; |
1da177e4 | 3973 | |
b7bb4c9b GS |
3974 | if (sds.this_load >= sds.avg_load) |
3975 | goto out_balanced; | |
3976 | ||
3977 | if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load) | |
1da177e4 LT |
3978 | goto out_balanced; |
3979 | ||
222d656d GS |
3980 | sds.busiest_load_per_task /= sds.busiest_nr_running; |
3981 | if (sds.group_imb) | |
3982 | sds.busiest_load_per_task = | |
3983 | min(sds.busiest_load_per_task, sds.avg_load); | |
908a7c1b | 3984 | |
1da177e4 LT |
3985 | /* |
3986 | * We're trying to get all the cpus to the average_load, so we don't | |
3987 | * want to push ourselves above the average load, nor do we wish to | |
3988 | * reduce the max loaded cpu below the average load, as either of these | |
3989 | * actions would just result in more rebalancing later, and ping-pong | |
3990 | * tasks around. Thus we look for the minimum possible imbalance. | |
3991 | * Negative imbalances (*we* are more loaded than anyone else) will | |
3992 | * be counted as no imbalance for these purposes -- we can't fix that | |
41a2d6cf | 3993 | * by pulling tasks to us. Be careful of negative numbers as they'll |
1da177e4 LT |
3994 | * appear as very large values with unsigned longs. |
3995 | */ | |
222d656d | 3996 | if (sds.max_load <= sds.busiest_load_per_task) |
2dd73a4f PW |
3997 | goto out_balanced; |
3998 | ||
dbc523a3 GS |
3999 | /* Looks like there is an imbalance. Compute it */ |
4000 | calculate_imbalance(&sds, this_cpu, imbalance); | |
222d656d | 4001 | return sds.busiest; |
1da177e4 LT |
4002 | |
4003 | out_balanced: | |
c071df18 GS |
4004 | /* |
4005 | * There is no obvious imbalance. But check if we can do some balancing | |
4006 | * to save power. | |
4007 | */ | |
4008 | if (check_power_save_busiest_group(&sds, this_cpu, imbalance)) | |
4009 | return sds.busiest; | |
783609c6 | 4010 | ret: |
1da177e4 LT |
4011 | *imbalance = 0; |
4012 | return NULL; | |
4013 | } | |
4014 | ||
bdb94aa5 PZ |
4015 | static struct sched_group *group_of(int cpu) |
4016 | { | |
4017 | struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); | |
4018 | ||
4019 | if (!sd) | |
4020 | return NULL; | |
4021 | ||
4022 | return sd->groups; | |
4023 | } | |
4024 | ||
4025 | static unsigned long power_of(int cpu) | |
4026 | { | |
4027 | struct sched_group *group = group_of(cpu); | |
4028 | ||
4029 | if (!group) | |
4030 | return SCHED_LOAD_SCALE; | |
4031 | ||
18a3885f | 4032 | return group->cpu_power; |
bdb94aa5 PZ |
4033 | } |
4034 | ||
1da177e4 LT |
4035 | /* |
4036 | * find_busiest_queue - find the busiest runqueue among the cpus in group. | |
4037 | */ | |
70b97a7f | 4038 | static struct rq * |
d15bcfdb | 4039 | find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, |
96f874e2 | 4040 | unsigned long imbalance, const struct cpumask *cpus) |
1da177e4 | 4041 | { |
70b97a7f | 4042 | struct rq *busiest = NULL, *rq; |
2dd73a4f | 4043 | unsigned long max_load = 0; |
1da177e4 LT |
4044 | int i; |
4045 | ||
758b2cdc | 4046 | for_each_cpu(i, sched_group_cpus(group)) { |
bdb94aa5 PZ |
4047 | unsigned long power = power_of(i); |
4048 | unsigned long capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); | |
dd41f596 | 4049 | unsigned long wl; |
0a2966b4 | 4050 | |
96f874e2 | 4051 | if (!cpumask_test_cpu(i, cpus)) |
0a2966b4 CL |
4052 | continue; |
4053 | ||
48f24c4d | 4054 | rq = cpu_rq(i); |
bdb94aa5 PZ |
4055 | wl = weighted_cpuload(i) * SCHED_LOAD_SCALE; |
4056 | wl /= power; | |
2dd73a4f | 4057 | |
bdb94aa5 | 4058 | if (capacity && rq->nr_running == 1 && wl > imbalance) |
2dd73a4f | 4059 | continue; |
1da177e4 | 4060 | |
dd41f596 IM |
4061 | if (wl > max_load) { |
4062 | max_load = wl; | |
48f24c4d | 4063 | busiest = rq; |
1da177e4 LT |
4064 | } |
4065 | } | |
4066 | ||
4067 | return busiest; | |
4068 | } | |
4069 | ||
77391d71 NP |
4070 | /* |
4071 | * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but | |
4072 | * so long as it is large enough. | |
4073 | */ | |
4074 | #define MAX_PINNED_INTERVAL 512 | |
4075 | ||
df7c8e84 RR |
4076 | /* Working cpumask for load_balance and load_balance_newidle. */ |
4077 | static DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask); | |
4078 | ||
1da177e4 LT |
4079 | /* |
4080 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
4081 | * tasks if there is an imbalance. | |
1da177e4 | 4082 | */ |
70b97a7f | 4083 | static int load_balance(int this_cpu, struct rq *this_rq, |
d15bcfdb | 4084 | struct sched_domain *sd, enum cpu_idle_type idle, |
df7c8e84 | 4085 | int *balance) |
1da177e4 | 4086 | { |
43010659 | 4087 | int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; |
1da177e4 | 4088 | struct sched_group *group; |
1da177e4 | 4089 | unsigned long imbalance; |
70b97a7f | 4090 | struct rq *busiest; |
fe2eea3f | 4091 | unsigned long flags; |
df7c8e84 | 4092 | struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); |
5969fe06 | 4093 | |
96f874e2 | 4094 | cpumask_setall(cpus); |
7c16ec58 | 4095 | |
89c4710e SS |
4096 | /* |
4097 | * When power savings policy is enabled for the parent domain, idle | |
4098 | * sibling can pick up load irrespective of busy siblings. In this case, | |
dd41f596 | 4099 | * let the state of idle sibling percolate up as CPU_IDLE, instead of |
d15bcfdb | 4100 | * portraying it as CPU_NOT_IDLE. |
89c4710e | 4101 | */ |
d15bcfdb | 4102 | if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4103 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 4104 | sd_idle = 1; |
1da177e4 | 4105 | |
2d72376b | 4106 | schedstat_inc(sd, lb_count[idle]); |
1da177e4 | 4107 | |
0a2966b4 | 4108 | redo: |
c8cba857 | 4109 | update_shares(sd); |
0a2966b4 | 4110 | group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, |
7c16ec58 | 4111 | cpus, balance); |
783609c6 | 4112 | |
06066714 | 4113 | if (*balance == 0) |
783609c6 | 4114 | goto out_balanced; |
783609c6 | 4115 | |
1da177e4 LT |
4116 | if (!group) { |
4117 | schedstat_inc(sd, lb_nobusyg[idle]); | |
4118 | goto out_balanced; | |
4119 | } | |
4120 | ||
7c16ec58 | 4121 | busiest = find_busiest_queue(group, idle, imbalance, cpus); |
1da177e4 LT |
4122 | if (!busiest) { |
4123 | schedstat_inc(sd, lb_nobusyq[idle]); | |
4124 | goto out_balanced; | |
4125 | } | |
4126 | ||
db935dbd | 4127 | BUG_ON(busiest == this_rq); |
1da177e4 LT |
4128 | |
4129 | schedstat_add(sd, lb_imbalance[idle], imbalance); | |
4130 | ||
43010659 | 4131 | ld_moved = 0; |
1da177e4 LT |
4132 | if (busiest->nr_running > 1) { |
4133 | /* | |
4134 | * Attempt to move tasks. If find_busiest_group has found | |
4135 | * an imbalance but busiest->nr_running <= 1, the group is | |
43010659 | 4136 | * still unbalanced. ld_moved simply stays zero, so it is |
1da177e4 LT |
4137 | * correctly treated as an imbalance. |
4138 | */ | |
fe2eea3f | 4139 | local_irq_save(flags); |
e17224bf | 4140 | double_rq_lock(this_rq, busiest); |
43010659 | 4141 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
48f24c4d | 4142 | imbalance, sd, idle, &all_pinned); |
e17224bf | 4143 | double_rq_unlock(this_rq, busiest); |
fe2eea3f | 4144 | local_irq_restore(flags); |
81026794 | 4145 | |
46cb4b7c SS |
4146 | /* |
4147 | * some other cpu did the load balance for us. | |
4148 | */ | |
43010659 | 4149 | if (ld_moved && this_cpu != smp_processor_id()) |
46cb4b7c SS |
4150 | resched_cpu(this_cpu); |
4151 | ||
81026794 | 4152 | /* All tasks on this runqueue were pinned by CPU affinity */ |
0a2966b4 | 4153 | if (unlikely(all_pinned)) { |
96f874e2 RR |
4154 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
4155 | if (!cpumask_empty(cpus)) | |
0a2966b4 | 4156 | goto redo; |
81026794 | 4157 | goto out_balanced; |
0a2966b4 | 4158 | } |
1da177e4 | 4159 | } |
81026794 | 4160 | |
43010659 | 4161 | if (!ld_moved) { |
1da177e4 LT |
4162 | schedstat_inc(sd, lb_failed[idle]); |
4163 | sd->nr_balance_failed++; | |
4164 | ||
4165 | if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { | |
1da177e4 | 4166 | |
fe2eea3f | 4167 | spin_lock_irqsave(&busiest->lock, flags); |
fa3b6ddc SS |
4168 | |
4169 | /* don't kick the migration_thread, if the curr | |
4170 | * task on busiest cpu can't be moved to this_cpu | |
4171 | */ | |
96f874e2 RR |
4172 | if (!cpumask_test_cpu(this_cpu, |
4173 | &busiest->curr->cpus_allowed)) { | |
fe2eea3f | 4174 | spin_unlock_irqrestore(&busiest->lock, flags); |
fa3b6ddc SS |
4175 | all_pinned = 1; |
4176 | goto out_one_pinned; | |
4177 | } | |
4178 | ||
1da177e4 LT |
4179 | if (!busiest->active_balance) { |
4180 | busiest->active_balance = 1; | |
4181 | busiest->push_cpu = this_cpu; | |
81026794 | 4182 | active_balance = 1; |
1da177e4 | 4183 | } |
fe2eea3f | 4184 | spin_unlock_irqrestore(&busiest->lock, flags); |
81026794 | 4185 | if (active_balance) |
1da177e4 LT |
4186 | wake_up_process(busiest->migration_thread); |
4187 | ||
4188 | /* | |
4189 | * We've kicked active balancing, reset the failure | |
4190 | * counter. | |
4191 | */ | |
39507451 | 4192 | sd->nr_balance_failed = sd->cache_nice_tries+1; |
1da177e4 | 4193 | } |
81026794 | 4194 | } else |
1da177e4 LT |
4195 | sd->nr_balance_failed = 0; |
4196 | ||
81026794 | 4197 | if (likely(!active_balance)) { |
1da177e4 LT |
4198 | /* We were unbalanced, so reset the balancing interval */ |
4199 | sd->balance_interval = sd->min_interval; | |
81026794 NP |
4200 | } else { |
4201 | /* | |
4202 | * If we've begun active balancing, start to back off. This | |
4203 | * case may not be covered by the all_pinned logic if there | |
4204 | * is only 1 task on the busy runqueue (because we don't call | |
4205 | * move_tasks). | |
4206 | */ | |
4207 | if (sd->balance_interval < sd->max_interval) | |
4208 | sd->balance_interval *= 2; | |
1da177e4 LT |
4209 | } |
4210 | ||
43010659 | 4211 | if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4212 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
4213 | ld_moved = -1; |
4214 | ||
4215 | goto out; | |
1da177e4 LT |
4216 | |
4217 | out_balanced: | |
1da177e4 LT |
4218 | schedstat_inc(sd, lb_balanced[idle]); |
4219 | ||
16cfb1c0 | 4220 | sd->nr_balance_failed = 0; |
fa3b6ddc SS |
4221 | |
4222 | out_one_pinned: | |
1da177e4 | 4223 | /* tune up the balancing interval */ |
77391d71 NP |
4224 | if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || |
4225 | (sd->balance_interval < sd->max_interval)) | |
1da177e4 LT |
4226 | sd->balance_interval *= 2; |
4227 | ||
48f24c4d | 4228 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4229 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
4230 | ld_moved = -1; |
4231 | else | |
4232 | ld_moved = 0; | |
4233 | out: | |
c8cba857 PZ |
4234 | if (ld_moved) |
4235 | update_shares(sd); | |
c09595f6 | 4236 | return ld_moved; |
1da177e4 LT |
4237 | } |
4238 | ||
4239 | /* | |
4240 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
4241 | * tasks if there is an imbalance. | |
4242 | * | |
d15bcfdb | 4243 | * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). |
1da177e4 LT |
4244 | * this_rq is locked. |
4245 | */ | |
48f24c4d | 4246 | static int |
df7c8e84 | 4247 | load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) |
1da177e4 LT |
4248 | { |
4249 | struct sched_group *group; | |
70b97a7f | 4250 | struct rq *busiest = NULL; |
1da177e4 | 4251 | unsigned long imbalance; |
43010659 | 4252 | int ld_moved = 0; |
5969fe06 | 4253 | int sd_idle = 0; |
969bb4e4 | 4254 | int all_pinned = 0; |
df7c8e84 | 4255 | struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); |
7c16ec58 | 4256 | |
96f874e2 | 4257 | cpumask_setall(cpus); |
5969fe06 | 4258 | |
89c4710e SS |
4259 | /* |
4260 | * When power savings policy is enabled for the parent domain, idle | |
4261 | * sibling can pick up load irrespective of busy siblings. In this case, | |
4262 | * let the state of idle sibling percolate up as IDLE, instead of | |
d15bcfdb | 4263 | * portraying it as CPU_NOT_IDLE. |
89c4710e SS |
4264 | */ |
4265 | if (sd->flags & SD_SHARE_CPUPOWER && | |
4266 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 4267 | sd_idle = 1; |
1da177e4 | 4268 | |
2d72376b | 4269 | schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); |
0a2966b4 | 4270 | redo: |
3e5459b4 | 4271 | update_shares_locked(this_rq, sd); |
d15bcfdb | 4272 | group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, |
7c16ec58 | 4273 | &sd_idle, cpus, NULL); |
1da177e4 | 4274 | if (!group) { |
d15bcfdb | 4275 | schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); |
16cfb1c0 | 4276 | goto out_balanced; |
1da177e4 LT |
4277 | } |
4278 | ||
7c16ec58 | 4279 | busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); |
db935dbd | 4280 | if (!busiest) { |
d15bcfdb | 4281 | schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); |
16cfb1c0 | 4282 | goto out_balanced; |
1da177e4 LT |
4283 | } |
4284 | ||
db935dbd NP |
4285 | BUG_ON(busiest == this_rq); |
4286 | ||
d15bcfdb | 4287 | schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); |
d6d5cfaf | 4288 | |
43010659 | 4289 | ld_moved = 0; |
d6d5cfaf NP |
4290 | if (busiest->nr_running > 1) { |
4291 | /* Attempt to move tasks */ | |
4292 | double_lock_balance(this_rq, busiest); | |
6e82a3be IM |
4293 | /* this_rq->clock is already updated */ |
4294 | update_rq_clock(busiest); | |
43010659 | 4295 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
969bb4e4 SS |
4296 | imbalance, sd, CPU_NEWLY_IDLE, |
4297 | &all_pinned); | |
1b12bbc7 | 4298 | double_unlock_balance(this_rq, busiest); |
0a2966b4 | 4299 | |
969bb4e4 | 4300 | if (unlikely(all_pinned)) { |
96f874e2 RR |
4301 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
4302 | if (!cpumask_empty(cpus)) | |
0a2966b4 CL |
4303 | goto redo; |
4304 | } | |
d6d5cfaf NP |
4305 | } |
4306 | ||
43010659 | 4307 | if (!ld_moved) { |
36dffab6 | 4308 | int active_balance = 0; |
ad273b32 | 4309 | |
d15bcfdb | 4310 | schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); |
89c4710e SS |
4311 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
4312 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 4313 | return -1; |
ad273b32 VS |
4314 | |
4315 | if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP) | |
4316 | return -1; | |
4317 | ||
4318 | if (sd->nr_balance_failed++ < 2) | |
4319 | return -1; | |
4320 | ||
4321 | /* | |
4322 | * The only task running in a non-idle cpu can be moved to this | |
4323 | * cpu in an attempt to completely freeup the other CPU | |
4324 | * package. The same method used to move task in load_balance() | |
4325 | * have been extended for load_balance_newidle() to speedup | |
4326 | * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2) | |
4327 | * | |
4328 | * The package power saving logic comes from | |
4329 | * find_busiest_group(). If there are no imbalance, then | |
4330 | * f_b_g() will return NULL. However when sched_mc={1,2} then | |
4331 | * f_b_g() will select a group from which a running task may be | |
4332 | * pulled to this cpu in order to make the other package idle. | |
4333 | * If there is no opportunity to make a package idle and if | |
4334 | * there are no imbalance, then f_b_g() will return NULL and no | |
4335 | * action will be taken in load_balance_newidle(). | |
4336 | * | |
4337 | * Under normal task pull operation due to imbalance, there | |
4338 | * will be more than one task in the source run queue and | |
4339 | * move_tasks() will succeed. ld_moved will be true and this | |
4340 | * active balance code will not be triggered. | |
4341 | */ | |
4342 | ||
4343 | /* Lock busiest in correct order while this_rq is held */ | |
4344 | double_lock_balance(this_rq, busiest); | |
4345 | ||
4346 | /* | |
4347 | * don't kick the migration_thread, if the curr | |
4348 | * task on busiest cpu can't be moved to this_cpu | |
4349 | */ | |
6ca09dfc | 4350 | if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { |
ad273b32 VS |
4351 | double_unlock_balance(this_rq, busiest); |
4352 | all_pinned = 1; | |
4353 | return ld_moved; | |
4354 | } | |
4355 | ||
4356 | if (!busiest->active_balance) { | |
4357 | busiest->active_balance = 1; | |
4358 | busiest->push_cpu = this_cpu; | |
4359 | active_balance = 1; | |
4360 | } | |
4361 | ||
4362 | double_unlock_balance(this_rq, busiest); | |
da8d5089 PZ |
4363 | /* |
4364 | * Should not call ttwu while holding a rq->lock | |
4365 | */ | |
4366 | spin_unlock(&this_rq->lock); | |
ad273b32 VS |
4367 | if (active_balance) |
4368 | wake_up_process(busiest->migration_thread); | |
da8d5089 | 4369 | spin_lock(&this_rq->lock); |
ad273b32 | 4370 | |
5969fe06 | 4371 | } else |
16cfb1c0 | 4372 | sd->nr_balance_failed = 0; |
1da177e4 | 4373 | |
3e5459b4 | 4374 | update_shares_locked(this_rq, sd); |
43010659 | 4375 | return ld_moved; |
16cfb1c0 NP |
4376 | |
4377 | out_balanced: | |
d15bcfdb | 4378 | schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); |
48f24c4d | 4379 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4380 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 4381 | return -1; |
16cfb1c0 | 4382 | sd->nr_balance_failed = 0; |
48f24c4d | 4383 | |
16cfb1c0 | 4384 | return 0; |
1da177e4 LT |
4385 | } |
4386 | ||
4387 | /* | |
4388 | * idle_balance is called by schedule() if this_cpu is about to become | |
4389 | * idle. Attempts to pull tasks from other CPUs. | |
4390 | */ | |
70b97a7f | 4391 | static void idle_balance(int this_cpu, struct rq *this_rq) |
1da177e4 LT |
4392 | { |
4393 | struct sched_domain *sd; | |
efbe027e | 4394 | int pulled_task = 0; |
dd41f596 | 4395 | unsigned long next_balance = jiffies + HZ; |
1da177e4 LT |
4396 | |
4397 | for_each_domain(this_cpu, sd) { | |
92c4ca5c CL |
4398 | unsigned long interval; |
4399 | ||
4400 | if (!(sd->flags & SD_LOAD_BALANCE)) | |
4401 | continue; | |
4402 | ||
4403 | if (sd->flags & SD_BALANCE_NEWIDLE) | |
48f24c4d | 4404 | /* If we've pulled tasks over stop searching: */ |
7c16ec58 | 4405 | pulled_task = load_balance_newidle(this_cpu, this_rq, |
df7c8e84 | 4406 | sd); |
92c4ca5c CL |
4407 | |
4408 | interval = msecs_to_jiffies(sd->balance_interval); | |
4409 | if (time_after(next_balance, sd->last_balance + interval)) | |
4410 | next_balance = sd->last_balance + interval; | |
4411 | if (pulled_task) | |
4412 | break; | |
1da177e4 | 4413 | } |
dd41f596 | 4414 | if (pulled_task || time_after(jiffies, this_rq->next_balance)) { |
1bd77f2d CL |
4415 | /* |
4416 | * We are going idle. next_balance may be set based on | |
4417 | * a busy processor. So reset next_balance. | |
4418 | */ | |
4419 | this_rq->next_balance = next_balance; | |
dd41f596 | 4420 | } |
1da177e4 LT |
4421 | } |
4422 | ||
4423 | /* | |
4424 | * active_load_balance is run by migration threads. It pushes running tasks | |
4425 | * off the busiest CPU onto idle CPUs. It requires at least 1 task to be | |
4426 | * running on each physical CPU where possible, and avoids physical / | |
4427 | * logical imbalances. | |
4428 | * | |
4429 | * Called with busiest_rq locked. | |
4430 | */ | |
70b97a7f | 4431 | static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) |
1da177e4 | 4432 | { |
39507451 | 4433 | int target_cpu = busiest_rq->push_cpu; |
70b97a7f IM |
4434 | struct sched_domain *sd; |
4435 | struct rq *target_rq; | |
39507451 | 4436 | |
48f24c4d | 4437 | /* Is there any task to move? */ |
39507451 | 4438 | if (busiest_rq->nr_running <= 1) |
39507451 NP |
4439 | return; |
4440 | ||
4441 | target_rq = cpu_rq(target_cpu); | |
1da177e4 LT |
4442 | |
4443 | /* | |
39507451 | 4444 | * This condition is "impossible", if it occurs |
41a2d6cf | 4445 | * we need to fix it. Originally reported by |
39507451 | 4446 | * Bjorn Helgaas on a 128-cpu setup. |
1da177e4 | 4447 | */ |
39507451 | 4448 | BUG_ON(busiest_rq == target_rq); |
1da177e4 | 4449 | |
39507451 NP |
4450 | /* move a task from busiest_rq to target_rq */ |
4451 | double_lock_balance(busiest_rq, target_rq); | |
6e82a3be IM |
4452 | update_rq_clock(busiest_rq); |
4453 | update_rq_clock(target_rq); | |
39507451 NP |
4454 | |
4455 | /* Search for an sd spanning us and the target CPU. */ | |
c96d145e | 4456 | for_each_domain(target_cpu, sd) { |
39507451 | 4457 | if ((sd->flags & SD_LOAD_BALANCE) && |
758b2cdc | 4458 | cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) |
39507451 | 4459 | break; |
c96d145e | 4460 | } |
39507451 | 4461 | |
48f24c4d | 4462 | if (likely(sd)) { |
2d72376b | 4463 | schedstat_inc(sd, alb_count); |
39507451 | 4464 | |
43010659 PW |
4465 | if (move_one_task(target_rq, target_cpu, busiest_rq, |
4466 | sd, CPU_IDLE)) | |
48f24c4d IM |
4467 | schedstat_inc(sd, alb_pushed); |
4468 | else | |
4469 | schedstat_inc(sd, alb_failed); | |
4470 | } | |
1b12bbc7 | 4471 | double_unlock_balance(busiest_rq, target_rq); |
1da177e4 LT |
4472 | } |
4473 | ||
46cb4b7c SS |
4474 | #ifdef CONFIG_NO_HZ |
4475 | static struct { | |
4476 | atomic_t load_balancer; | |
7d1e6a9b | 4477 | cpumask_var_t cpu_mask; |
f711f609 | 4478 | cpumask_var_t ilb_grp_nohz_mask; |
46cb4b7c SS |
4479 | } nohz ____cacheline_aligned = { |
4480 | .load_balancer = ATOMIC_INIT(-1), | |
46cb4b7c SS |
4481 | }; |
4482 | ||
eea08f32 AB |
4483 | int get_nohz_load_balancer(void) |
4484 | { | |
4485 | return atomic_read(&nohz.load_balancer); | |
4486 | } | |
4487 | ||
f711f609 GS |
4488 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
4489 | /** | |
4490 | * lowest_flag_domain - Return lowest sched_domain containing flag. | |
4491 | * @cpu: The cpu whose lowest level of sched domain is to | |
4492 | * be returned. | |
4493 | * @flag: The flag to check for the lowest sched_domain | |
4494 | * for the given cpu. | |
4495 | * | |
4496 | * Returns the lowest sched_domain of a cpu which contains the given flag. | |
4497 | */ | |
4498 | static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) | |
4499 | { | |
4500 | struct sched_domain *sd; | |
4501 | ||
4502 | for_each_domain(cpu, sd) | |
4503 | if (sd && (sd->flags & flag)) | |
4504 | break; | |
4505 | ||
4506 | return sd; | |
4507 | } | |
4508 | ||
4509 | /** | |
4510 | * for_each_flag_domain - Iterates over sched_domains containing the flag. | |
4511 | * @cpu: The cpu whose domains we're iterating over. | |
4512 | * @sd: variable holding the value of the power_savings_sd | |
4513 | * for cpu. | |
4514 | * @flag: The flag to filter the sched_domains to be iterated. | |
4515 | * | |
4516 | * Iterates over all the scheduler domains for a given cpu that has the 'flag' | |
4517 | * set, starting from the lowest sched_domain to the highest. | |
4518 | */ | |
4519 | #define for_each_flag_domain(cpu, sd, flag) \ | |
4520 | for (sd = lowest_flag_domain(cpu, flag); \ | |
4521 | (sd && (sd->flags & flag)); sd = sd->parent) | |
4522 | ||
4523 | /** | |
4524 | * is_semi_idle_group - Checks if the given sched_group is semi-idle. | |
4525 | * @ilb_group: group to be checked for semi-idleness | |
4526 | * | |
4527 | * Returns: 1 if the group is semi-idle. 0 otherwise. | |
4528 | * | |
4529 | * We define a sched_group to be semi idle if it has atleast one idle-CPU | |
4530 | * and atleast one non-idle CPU. This helper function checks if the given | |
4531 | * sched_group is semi-idle or not. | |
4532 | */ | |
4533 | static inline int is_semi_idle_group(struct sched_group *ilb_group) | |
4534 | { | |
4535 | cpumask_and(nohz.ilb_grp_nohz_mask, nohz.cpu_mask, | |
4536 | sched_group_cpus(ilb_group)); | |
4537 | ||
4538 | /* | |
4539 | * A sched_group is semi-idle when it has atleast one busy cpu | |
4540 | * and atleast one idle cpu. | |
4541 | */ | |
4542 | if (cpumask_empty(nohz.ilb_grp_nohz_mask)) | |
4543 | return 0; | |
4544 | ||
4545 | if (cpumask_equal(nohz.ilb_grp_nohz_mask, sched_group_cpus(ilb_group))) | |
4546 | return 0; | |
4547 | ||
4548 | return 1; | |
4549 | } | |
4550 | /** | |
4551 | * find_new_ilb - Finds the optimum idle load balancer for nomination. | |
4552 | * @cpu: The cpu which is nominating a new idle_load_balancer. | |
4553 | * | |
4554 | * Returns: Returns the id of the idle load balancer if it exists, | |
4555 | * Else, returns >= nr_cpu_ids. | |
4556 | * | |
4557 | * This algorithm picks the idle load balancer such that it belongs to a | |
4558 | * semi-idle powersavings sched_domain. The idea is to try and avoid | |
4559 | * completely idle packages/cores just for the purpose of idle load balancing | |
4560 | * when there are other idle cpu's which are better suited for that job. | |
4561 | */ | |
4562 | static int find_new_ilb(int cpu) | |
4563 | { | |
4564 | struct sched_domain *sd; | |
4565 | struct sched_group *ilb_group; | |
4566 | ||
4567 | /* | |
4568 | * Have idle load balancer selection from semi-idle packages only | |
4569 | * when power-aware load balancing is enabled | |
4570 | */ | |
4571 | if (!(sched_smt_power_savings || sched_mc_power_savings)) | |
4572 | goto out_done; | |
4573 | ||
4574 | /* | |
4575 | * Optimize for the case when we have no idle CPUs or only one | |
4576 | * idle CPU. Don't walk the sched_domain hierarchy in such cases | |
4577 | */ | |
4578 | if (cpumask_weight(nohz.cpu_mask) < 2) | |
4579 | goto out_done; | |
4580 | ||
4581 | for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) { | |
4582 | ilb_group = sd->groups; | |
4583 | ||
4584 | do { | |
4585 | if (is_semi_idle_group(ilb_group)) | |
4586 | return cpumask_first(nohz.ilb_grp_nohz_mask); | |
4587 | ||
4588 | ilb_group = ilb_group->next; | |
4589 | ||
4590 | } while (ilb_group != sd->groups); | |
4591 | } | |
4592 | ||
4593 | out_done: | |
4594 | return cpumask_first(nohz.cpu_mask); | |
4595 | } | |
4596 | #else /* (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */ | |
4597 | static inline int find_new_ilb(int call_cpu) | |
4598 | { | |
6e29ec57 | 4599 | return cpumask_first(nohz.cpu_mask); |
f711f609 GS |
4600 | } |
4601 | #endif | |
4602 | ||
7835b98b | 4603 | /* |
46cb4b7c SS |
4604 | * This routine will try to nominate the ilb (idle load balancing) |
4605 | * owner among the cpus whose ticks are stopped. ilb owner will do the idle | |
4606 | * load balancing on behalf of all those cpus. If all the cpus in the system | |
4607 | * go into this tickless mode, then there will be no ilb owner (as there is | |
4608 | * no need for one) and all the cpus will sleep till the next wakeup event | |
4609 | * arrives... | |
4610 | * | |
4611 | * For the ilb owner, tick is not stopped. And this tick will be used | |
4612 | * for idle load balancing. ilb owner will still be part of | |
4613 | * nohz.cpu_mask.. | |
7835b98b | 4614 | * |
46cb4b7c SS |
4615 | * While stopping the tick, this cpu will become the ilb owner if there |
4616 | * is no other owner. And will be the owner till that cpu becomes busy | |
4617 | * or if all cpus in the system stop their ticks at which point | |
4618 | * there is no need for ilb owner. | |
4619 | * | |
4620 | * When the ilb owner becomes busy, it nominates another owner, during the | |
4621 | * next busy scheduler_tick() | |
4622 | */ | |
4623 | int select_nohz_load_balancer(int stop_tick) | |
4624 | { | |
4625 | int cpu = smp_processor_id(); | |
4626 | ||
4627 | if (stop_tick) { | |
46cb4b7c SS |
4628 | cpu_rq(cpu)->in_nohz_recently = 1; |
4629 | ||
483b4ee6 SS |
4630 | if (!cpu_active(cpu)) { |
4631 | if (atomic_read(&nohz.load_balancer) != cpu) | |
4632 | return 0; | |
4633 | ||
4634 | /* | |
4635 | * If we are going offline and still the leader, | |
4636 | * give up! | |
4637 | */ | |
46cb4b7c SS |
4638 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) |
4639 | BUG(); | |
483b4ee6 | 4640 | |
46cb4b7c SS |
4641 | return 0; |
4642 | } | |
4643 | ||
483b4ee6 SS |
4644 | cpumask_set_cpu(cpu, nohz.cpu_mask); |
4645 | ||
46cb4b7c | 4646 | /* time for ilb owner also to sleep */ |
7d1e6a9b | 4647 | if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
4648 | if (atomic_read(&nohz.load_balancer) == cpu) |
4649 | atomic_set(&nohz.load_balancer, -1); | |
4650 | return 0; | |
4651 | } | |
4652 | ||
4653 | if (atomic_read(&nohz.load_balancer) == -1) { | |
4654 | /* make me the ilb owner */ | |
4655 | if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) | |
4656 | return 1; | |
e790fb0b GS |
4657 | } else if (atomic_read(&nohz.load_balancer) == cpu) { |
4658 | int new_ilb; | |
4659 | ||
4660 | if (!(sched_smt_power_savings || | |
4661 | sched_mc_power_savings)) | |
4662 | return 1; | |
4663 | /* | |
4664 | * Check to see if there is a more power-efficient | |
4665 | * ilb. | |
4666 | */ | |
4667 | new_ilb = find_new_ilb(cpu); | |
4668 | if (new_ilb < nr_cpu_ids && new_ilb != cpu) { | |
4669 | atomic_set(&nohz.load_balancer, -1); | |
4670 | resched_cpu(new_ilb); | |
4671 | return 0; | |
4672 | } | |
46cb4b7c | 4673 | return 1; |
e790fb0b | 4674 | } |
46cb4b7c | 4675 | } else { |
7d1e6a9b | 4676 | if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4677 | return 0; |
4678 | ||
7d1e6a9b | 4679 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4680 | |
4681 | if (atomic_read(&nohz.load_balancer) == cpu) | |
4682 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
4683 | BUG(); | |
4684 | } | |
4685 | return 0; | |
4686 | } | |
4687 | #endif | |
4688 | ||
4689 | static DEFINE_SPINLOCK(balancing); | |
4690 | ||
4691 | /* | |
7835b98b CL |
4692 | * It checks each scheduling domain to see if it is due to be balanced, |
4693 | * and initiates a balancing operation if so. | |
4694 | * | |
4695 | * Balancing parameters are set up in arch_init_sched_domains. | |
4696 | */ | |
a9957449 | 4697 | static void rebalance_domains(int cpu, enum cpu_idle_type idle) |
7835b98b | 4698 | { |
46cb4b7c SS |
4699 | int balance = 1; |
4700 | struct rq *rq = cpu_rq(cpu); | |
7835b98b CL |
4701 | unsigned long interval; |
4702 | struct sched_domain *sd; | |
46cb4b7c | 4703 | /* Earliest time when we have to do rebalance again */ |
c9819f45 | 4704 | unsigned long next_balance = jiffies + 60*HZ; |
f549da84 | 4705 | int update_next_balance = 0; |
d07355f5 | 4706 | int need_serialize; |
1da177e4 | 4707 | |
46cb4b7c | 4708 | for_each_domain(cpu, sd) { |
1da177e4 LT |
4709 | if (!(sd->flags & SD_LOAD_BALANCE)) |
4710 | continue; | |
4711 | ||
4712 | interval = sd->balance_interval; | |
d15bcfdb | 4713 | if (idle != CPU_IDLE) |
1da177e4 LT |
4714 | interval *= sd->busy_factor; |
4715 | ||
4716 | /* scale ms to jiffies */ | |
4717 | interval = msecs_to_jiffies(interval); | |
4718 | if (unlikely(!interval)) | |
4719 | interval = 1; | |
dd41f596 IM |
4720 | if (interval > HZ*NR_CPUS/10) |
4721 | interval = HZ*NR_CPUS/10; | |
4722 | ||
d07355f5 | 4723 | need_serialize = sd->flags & SD_SERIALIZE; |
1da177e4 | 4724 | |
d07355f5 | 4725 | if (need_serialize) { |
08c183f3 CL |
4726 | if (!spin_trylock(&balancing)) |
4727 | goto out; | |
4728 | } | |
4729 | ||
c9819f45 | 4730 | if (time_after_eq(jiffies, sd->last_balance + interval)) { |
df7c8e84 | 4731 | if (load_balance(cpu, rq, sd, idle, &balance)) { |
fa3b6ddc SS |
4732 | /* |
4733 | * We've pulled tasks over so either we're no | |
5969fe06 NP |
4734 | * longer idle, or one of our SMT siblings is |
4735 | * not idle. | |
4736 | */ | |
d15bcfdb | 4737 | idle = CPU_NOT_IDLE; |
1da177e4 | 4738 | } |
1bd77f2d | 4739 | sd->last_balance = jiffies; |
1da177e4 | 4740 | } |
d07355f5 | 4741 | if (need_serialize) |
08c183f3 CL |
4742 | spin_unlock(&balancing); |
4743 | out: | |
f549da84 | 4744 | if (time_after(next_balance, sd->last_balance + interval)) { |
c9819f45 | 4745 | next_balance = sd->last_balance + interval; |
f549da84 SS |
4746 | update_next_balance = 1; |
4747 | } | |
783609c6 SS |
4748 | |
4749 | /* | |
4750 | * Stop the load balance at this level. There is another | |
4751 | * CPU in our sched group which is doing load balancing more | |
4752 | * actively. | |
4753 | */ | |
4754 | if (!balance) | |
4755 | break; | |
1da177e4 | 4756 | } |
f549da84 SS |
4757 | |
4758 | /* | |
4759 | * next_balance will be updated only when there is a need. | |
4760 | * When the cpu is attached to null domain for ex, it will not be | |
4761 | * updated. | |
4762 | */ | |
4763 | if (likely(update_next_balance)) | |
4764 | rq->next_balance = next_balance; | |
46cb4b7c SS |
4765 | } |
4766 | ||
4767 | /* | |
4768 | * run_rebalance_domains is triggered when needed from the scheduler tick. | |
4769 | * In CONFIG_NO_HZ case, the idle load balance owner will do the | |
4770 | * rebalancing for all the cpus for whom scheduler ticks are stopped. | |
4771 | */ | |
4772 | static void run_rebalance_domains(struct softirq_action *h) | |
4773 | { | |
dd41f596 IM |
4774 | int this_cpu = smp_processor_id(); |
4775 | struct rq *this_rq = cpu_rq(this_cpu); | |
4776 | enum cpu_idle_type idle = this_rq->idle_at_tick ? | |
4777 | CPU_IDLE : CPU_NOT_IDLE; | |
46cb4b7c | 4778 | |
dd41f596 | 4779 | rebalance_domains(this_cpu, idle); |
46cb4b7c SS |
4780 | |
4781 | #ifdef CONFIG_NO_HZ | |
4782 | /* | |
4783 | * If this cpu is the owner for idle load balancing, then do the | |
4784 | * balancing on behalf of the other idle cpus whose ticks are | |
4785 | * stopped. | |
4786 | */ | |
dd41f596 IM |
4787 | if (this_rq->idle_at_tick && |
4788 | atomic_read(&nohz.load_balancer) == this_cpu) { | |
46cb4b7c SS |
4789 | struct rq *rq; |
4790 | int balance_cpu; | |
4791 | ||
7d1e6a9b RR |
4792 | for_each_cpu(balance_cpu, nohz.cpu_mask) { |
4793 | if (balance_cpu == this_cpu) | |
4794 | continue; | |
4795 | ||
46cb4b7c SS |
4796 | /* |
4797 | * If this cpu gets work to do, stop the load balancing | |
4798 | * work being done for other cpus. Next load | |
4799 | * balancing owner will pick it up. | |
4800 | */ | |
4801 | if (need_resched()) | |
4802 | break; | |
4803 | ||
de0cf899 | 4804 | rebalance_domains(balance_cpu, CPU_IDLE); |
46cb4b7c SS |
4805 | |
4806 | rq = cpu_rq(balance_cpu); | |
dd41f596 IM |
4807 | if (time_after(this_rq->next_balance, rq->next_balance)) |
4808 | this_rq->next_balance = rq->next_balance; | |
46cb4b7c SS |
4809 | } |
4810 | } | |
4811 | #endif | |
4812 | } | |
4813 | ||
8a0be9ef FW |
4814 | static inline int on_null_domain(int cpu) |
4815 | { | |
4816 | return !rcu_dereference(cpu_rq(cpu)->sd); | |
4817 | } | |
4818 | ||
46cb4b7c SS |
4819 | /* |
4820 | * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. | |
4821 | * | |
4822 | * In case of CONFIG_NO_HZ, this is the place where we nominate a new | |
4823 | * idle load balancing owner or decide to stop the periodic load balancing, | |
4824 | * if the whole system is idle. | |
4825 | */ | |
dd41f596 | 4826 | static inline void trigger_load_balance(struct rq *rq, int cpu) |
46cb4b7c | 4827 | { |
46cb4b7c SS |
4828 | #ifdef CONFIG_NO_HZ |
4829 | /* | |
4830 | * If we were in the nohz mode recently and busy at the current | |
4831 | * scheduler tick, then check if we need to nominate new idle | |
4832 | * load balancer. | |
4833 | */ | |
4834 | if (rq->in_nohz_recently && !rq->idle_at_tick) { | |
4835 | rq->in_nohz_recently = 0; | |
4836 | ||
4837 | if (atomic_read(&nohz.load_balancer) == cpu) { | |
7d1e6a9b | 4838 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4839 | atomic_set(&nohz.load_balancer, -1); |
4840 | } | |
4841 | ||
4842 | if (atomic_read(&nohz.load_balancer) == -1) { | |
f711f609 | 4843 | int ilb = find_new_ilb(cpu); |
46cb4b7c | 4844 | |
434d53b0 | 4845 | if (ilb < nr_cpu_ids) |
46cb4b7c SS |
4846 | resched_cpu(ilb); |
4847 | } | |
4848 | } | |
4849 | ||
4850 | /* | |
4851 | * If this cpu is idle and doing idle load balancing for all the | |
4852 | * cpus with ticks stopped, is it time for that to stop? | |
4853 | */ | |
4854 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && | |
7d1e6a9b | 4855 | cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
4856 | resched_cpu(cpu); |
4857 | return; | |
4858 | } | |
4859 | ||
4860 | /* | |
4861 | * If this cpu is idle and the idle load balancing is done by | |
4862 | * someone else, then no need raise the SCHED_SOFTIRQ | |
4863 | */ | |
4864 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && | |
7d1e6a9b | 4865 | cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4866 | return; |
4867 | #endif | |
8a0be9ef FW |
4868 | /* Don't need to rebalance while attached to NULL domain */ |
4869 | if (time_after_eq(jiffies, rq->next_balance) && | |
4870 | likely(!on_null_domain(cpu))) | |
46cb4b7c | 4871 | raise_softirq(SCHED_SOFTIRQ); |
1da177e4 | 4872 | } |
dd41f596 IM |
4873 | |
4874 | #else /* CONFIG_SMP */ | |
4875 | ||
1da177e4 LT |
4876 | /* |
4877 | * on UP we do not need to balance between CPUs: | |
4878 | */ | |
70b97a7f | 4879 | static inline void idle_balance(int cpu, struct rq *rq) |
1da177e4 LT |
4880 | { |
4881 | } | |
dd41f596 | 4882 | |
1da177e4 LT |
4883 | #endif |
4884 | ||
1da177e4 LT |
4885 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
4886 | ||
4887 | EXPORT_PER_CPU_SYMBOL(kstat); | |
4888 | ||
4889 | /* | |
c5f8d995 | 4890 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 4891 | * @p in case that task is currently running. |
c5f8d995 HS |
4892 | * |
4893 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 4894 | */ |
c5f8d995 HS |
4895 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
4896 | { | |
4897 | u64 ns = 0; | |
4898 | ||
4899 | if (task_current(rq, p)) { | |
4900 | update_rq_clock(rq); | |
4901 | ns = rq->clock - p->se.exec_start; | |
4902 | if ((s64)ns < 0) | |
4903 | ns = 0; | |
4904 | } | |
4905 | ||
4906 | return ns; | |
4907 | } | |
4908 | ||
bb34d92f | 4909 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 4910 | { |
1da177e4 | 4911 | unsigned long flags; |
41b86e9c | 4912 | struct rq *rq; |
bb34d92f | 4913 | u64 ns = 0; |
48f24c4d | 4914 | |
41b86e9c | 4915 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
4916 | ns = do_task_delta_exec(p, rq); |
4917 | task_rq_unlock(rq, &flags); | |
1508487e | 4918 | |
c5f8d995 HS |
4919 | return ns; |
4920 | } | |
f06febc9 | 4921 | |
c5f8d995 HS |
4922 | /* |
4923 | * Return accounted runtime for the task. | |
4924 | * In case the task is currently running, return the runtime plus current's | |
4925 | * pending runtime that have not been accounted yet. | |
4926 | */ | |
4927 | unsigned long long task_sched_runtime(struct task_struct *p) | |
4928 | { | |
4929 | unsigned long flags; | |
4930 | struct rq *rq; | |
4931 | u64 ns = 0; | |
4932 | ||
4933 | rq = task_rq_lock(p, &flags); | |
4934 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
4935 | task_rq_unlock(rq, &flags); | |
4936 | ||
4937 | return ns; | |
4938 | } | |
48f24c4d | 4939 | |
c5f8d995 HS |
4940 | /* |
4941 | * Return sum_exec_runtime for the thread group. | |
4942 | * In case the task is currently running, return the sum plus current's | |
4943 | * pending runtime that have not been accounted yet. | |
4944 | * | |
4945 | * Note that the thread group might have other running tasks as well, | |
4946 | * so the return value not includes other pending runtime that other | |
4947 | * running tasks might have. | |
4948 | */ | |
4949 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
4950 | { | |
4951 | struct task_cputime totals; | |
4952 | unsigned long flags; | |
4953 | struct rq *rq; | |
4954 | u64 ns; | |
4955 | ||
4956 | rq = task_rq_lock(p, &flags); | |
4957 | thread_group_cputime(p, &totals); | |
4958 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 4959 | task_rq_unlock(rq, &flags); |
48f24c4d | 4960 | |
1da177e4 LT |
4961 | return ns; |
4962 | } | |
4963 | ||
1da177e4 LT |
4964 | /* |
4965 | * Account user cpu time to a process. | |
4966 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 4967 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 4968 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 4969 | */ |
457533a7 MS |
4970 | void account_user_time(struct task_struct *p, cputime_t cputime, |
4971 | cputime_t cputime_scaled) | |
1da177e4 LT |
4972 | { |
4973 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4974 | cputime64_t tmp; | |
4975 | ||
457533a7 | 4976 | /* Add user time to process. */ |
1da177e4 | 4977 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 4978 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 4979 | account_group_user_time(p, cputime); |
1da177e4 LT |
4980 | |
4981 | /* Add user time to cpustat. */ | |
4982 | tmp = cputime_to_cputime64(cputime); | |
4983 | if (TASK_NICE(p) > 0) | |
4984 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
4985 | else | |
4986 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
4987 | |
4988 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
4989 | /* Account for user time used */ |
4990 | acct_update_integrals(p); | |
1da177e4 LT |
4991 | } |
4992 | ||
94886b84 LV |
4993 | /* |
4994 | * Account guest cpu time to a process. | |
4995 | * @p: the process that the cpu time gets accounted to | |
4996 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 4997 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 4998 | */ |
457533a7 MS |
4999 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
5000 | cputime_t cputime_scaled) | |
94886b84 LV |
5001 | { |
5002 | cputime64_t tmp; | |
5003 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
5004 | ||
5005 | tmp = cputime_to_cputime64(cputime); | |
5006 | ||
457533a7 | 5007 | /* Add guest time to process. */ |
94886b84 | 5008 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 5009 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 5010 | account_group_user_time(p, cputime); |
94886b84 LV |
5011 | p->gtime = cputime_add(p->gtime, cputime); |
5012 | ||
457533a7 | 5013 | /* Add guest time to cpustat. */ |
94886b84 LV |
5014 | cpustat->user = cputime64_add(cpustat->user, tmp); |
5015 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
5016 | } | |
5017 | ||
1da177e4 LT |
5018 | /* |
5019 | * Account system cpu time to a process. | |
5020 | * @p: the process that the cpu time gets accounted to | |
5021 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
5022 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 5023 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
5024 | */ |
5025 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 5026 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
5027 | { |
5028 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
5029 | cputime64_t tmp; |
5030 | ||
983ed7a6 | 5031 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 5032 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
5033 | return; |
5034 | } | |
94886b84 | 5035 | |
457533a7 | 5036 | /* Add system time to process. */ |
1da177e4 | 5037 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 5038 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 5039 | account_group_system_time(p, cputime); |
1da177e4 LT |
5040 | |
5041 | /* Add system time to cpustat. */ | |
5042 | tmp = cputime_to_cputime64(cputime); | |
5043 | if (hardirq_count() - hardirq_offset) | |
5044 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
5045 | else if (softirq_count()) | |
5046 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 5047 | else |
79741dd3 MS |
5048 | cpustat->system = cputime64_add(cpustat->system, tmp); |
5049 | ||
ef12fefa BR |
5050 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
5051 | ||
1da177e4 LT |
5052 | /* Account for system time used */ |
5053 | acct_update_integrals(p); | |
1da177e4 LT |
5054 | } |
5055 | ||
c66f08be | 5056 | /* |
1da177e4 | 5057 | * Account for involuntary wait time. |
1da177e4 | 5058 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 5059 | */ |
79741dd3 | 5060 | void account_steal_time(cputime_t cputime) |
c66f08be | 5061 | { |
79741dd3 MS |
5062 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
5063 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
5064 | ||
5065 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
5066 | } |
5067 | ||
1da177e4 | 5068 | /* |
79741dd3 MS |
5069 | * Account for idle time. |
5070 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 5071 | */ |
79741dd3 | 5072 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
5073 | { |
5074 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 5075 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 5076 | struct rq *rq = this_rq(); |
1da177e4 | 5077 | |
79741dd3 MS |
5078 | if (atomic_read(&rq->nr_iowait) > 0) |
5079 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
5080 | else | |
5081 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
5082 | } |
5083 | ||
79741dd3 MS |
5084 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
5085 | ||
5086 | /* | |
5087 | * Account a single tick of cpu time. | |
5088 | * @p: the process that the cpu time gets accounted to | |
5089 | * @user_tick: indicates if the tick is a user or a system tick | |
5090 | */ | |
5091 | void account_process_tick(struct task_struct *p, int user_tick) | |
5092 | { | |
5093 | cputime_t one_jiffy = jiffies_to_cputime(1); | |
5094 | cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy); | |
5095 | struct rq *rq = this_rq(); | |
5096 | ||
5097 | if (user_tick) | |
5098 | account_user_time(p, one_jiffy, one_jiffy_scaled); | |
f5f293a4 | 5099 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
79741dd3 MS |
5100 | account_system_time(p, HARDIRQ_OFFSET, one_jiffy, |
5101 | one_jiffy_scaled); | |
5102 | else | |
5103 | account_idle_time(one_jiffy); | |
5104 | } | |
5105 | ||
5106 | /* | |
5107 | * Account multiple ticks of steal time. | |
5108 | * @p: the process from which the cpu time has been stolen | |
5109 | * @ticks: number of stolen ticks | |
5110 | */ | |
5111 | void account_steal_ticks(unsigned long ticks) | |
5112 | { | |
5113 | account_steal_time(jiffies_to_cputime(ticks)); | |
5114 | } | |
5115 | ||
5116 | /* | |
5117 | * Account multiple ticks of idle time. | |
5118 | * @ticks: number of stolen ticks | |
5119 | */ | |
5120 | void account_idle_ticks(unsigned long ticks) | |
5121 | { | |
5122 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
5123 | } |
5124 | ||
79741dd3 MS |
5125 | #endif |
5126 | ||
49048622 BS |
5127 | /* |
5128 | * Use precise platform statistics if available: | |
5129 | */ | |
5130 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
5131 | cputime_t task_utime(struct task_struct *p) | |
5132 | { | |
5133 | return p->utime; | |
5134 | } | |
5135 | ||
5136 | cputime_t task_stime(struct task_struct *p) | |
5137 | { | |
5138 | return p->stime; | |
5139 | } | |
5140 | #else | |
5141 | cputime_t task_utime(struct task_struct *p) | |
5142 | { | |
5143 | clock_t utime = cputime_to_clock_t(p->utime), | |
5144 | total = utime + cputime_to_clock_t(p->stime); | |
5145 | u64 temp; | |
5146 | ||
5147 | /* | |
5148 | * Use CFS's precise accounting: | |
5149 | */ | |
5150 | temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); | |
5151 | ||
5152 | if (total) { | |
5153 | temp *= utime; | |
5154 | do_div(temp, total); | |
5155 | } | |
5156 | utime = (clock_t)temp; | |
5157 | ||
5158 | p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); | |
5159 | return p->prev_utime; | |
5160 | } | |
5161 | ||
5162 | cputime_t task_stime(struct task_struct *p) | |
5163 | { | |
5164 | clock_t stime; | |
5165 | ||
5166 | /* | |
5167 | * Use CFS's precise accounting. (we subtract utime from | |
5168 | * the total, to make sure the total observed by userspace | |
5169 | * grows monotonically - apps rely on that): | |
5170 | */ | |
5171 | stime = nsec_to_clock_t(p->se.sum_exec_runtime) - | |
5172 | cputime_to_clock_t(task_utime(p)); | |
5173 | ||
5174 | if (stime >= 0) | |
5175 | p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); | |
5176 | ||
5177 | return p->prev_stime; | |
5178 | } | |
5179 | #endif | |
5180 | ||
5181 | inline cputime_t task_gtime(struct task_struct *p) | |
5182 | { | |
5183 | return p->gtime; | |
5184 | } | |
5185 | ||
7835b98b CL |
5186 | /* |
5187 | * This function gets called by the timer code, with HZ frequency. | |
5188 | * We call it with interrupts disabled. | |
5189 | * | |
5190 | * It also gets called by the fork code, when changing the parent's | |
5191 | * timeslices. | |
5192 | */ | |
5193 | void scheduler_tick(void) | |
5194 | { | |
7835b98b CL |
5195 | int cpu = smp_processor_id(); |
5196 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 5197 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
5198 | |
5199 | sched_clock_tick(); | |
dd41f596 IM |
5200 | |
5201 | spin_lock(&rq->lock); | |
3e51f33f | 5202 | update_rq_clock(rq); |
f1a438d8 | 5203 | update_cpu_load(rq); |
fa85ae24 | 5204 | curr->sched_class->task_tick(rq, curr, 0); |
dd41f596 | 5205 | spin_unlock(&rq->lock); |
7835b98b | 5206 | |
e220d2dc PZ |
5207 | perf_counter_task_tick(curr, cpu); |
5208 | ||
e418e1c2 | 5209 | #ifdef CONFIG_SMP |
dd41f596 IM |
5210 | rq->idle_at_tick = idle_cpu(cpu); |
5211 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 5212 | #endif |
1da177e4 LT |
5213 | } |
5214 | ||
132380a0 | 5215 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
5216 | { |
5217 | if (in_lock_functions(addr)) { | |
5218 | addr = CALLER_ADDR2; | |
5219 | if (in_lock_functions(addr)) | |
5220 | addr = CALLER_ADDR3; | |
5221 | } | |
5222 | return addr; | |
5223 | } | |
1da177e4 | 5224 | |
7e49fcce SR |
5225 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
5226 | defined(CONFIG_PREEMPT_TRACER)) | |
5227 | ||
43627582 | 5228 | void __kprobes add_preempt_count(int val) |
1da177e4 | 5229 | { |
6cd8a4bb | 5230 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5231 | /* |
5232 | * Underflow? | |
5233 | */ | |
9a11b49a IM |
5234 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
5235 | return; | |
6cd8a4bb | 5236 | #endif |
1da177e4 | 5237 | preempt_count() += val; |
6cd8a4bb | 5238 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5239 | /* |
5240 | * Spinlock count overflowing soon? | |
5241 | */ | |
33859f7f MOS |
5242 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
5243 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
5244 | #endif |
5245 | if (preempt_count() == val) | |
5246 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
5247 | } |
5248 | EXPORT_SYMBOL(add_preempt_count); | |
5249 | ||
43627582 | 5250 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 5251 | { |
6cd8a4bb | 5252 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5253 | /* |
5254 | * Underflow? | |
5255 | */ | |
01e3eb82 | 5256 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 5257 | return; |
1da177e4 LT |
5258 | /* |
5259 | * Is the spinlock portion underflowing? | |
5260 | */ | |
9a11b49a IM |
5261 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
5262 | !(preempt_count() & PREEMPT_MASK))) | |
5263 | return; | |
6cd8a4bb | 5264 | #endif |
9a11b49a | 5265 | |
6cd8a4bb SR |
5266 | if (preempt_count() == val) |
5267 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
5268 | preempt_count() -= val; |
5269 | } | |
5270 | EXPORT_SYMBOL(sub_preempt_count); | |
5271 | ||
5272 | #endif | |
5273 | ||
5274 | /* | |
dd41f596 | 5275 | * Print scheduling while atomic bug: |
1da177e4 | 5276 | */ |
dd41f596 | 5277 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 5278 | { |
838225b4 SS |
5279 | struct pt_regs *regs = get_irq_regs(); |
5280 | ||
5281 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", | |
5282 | prev->comm, prev->pid, preempt_count()); | |
5283 | ||
dd41f596 | 5284 | debug_show_held_locks(prev); |
e21f5b15 | 5285 | print_modules(); |
dd41f596 IM |
5286 | if (irqs_disabled()) |
5287 | print_irqtrace_events(prev); | |
838225b4 SS |
5288 | |
5289 | if (regs) | |
5290 | show_regs(regs); | |
5291 | else | |
5292 | dump_stack(); | |
dd41f596 | 5293 | } |
1da177e4 | 5294 | |
dd41f596 IM |
5295 | /* |
5296 | * Various schedule()-time debugging checks and statistics: | |
5297 | */ | |
5298 | static inline void schedule_debug(struct task_struct *prev) | |
5299 | { | |
1da177e4 | 5300 | /* |
41a2d6cf | 5301 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
5302 | * schedule() atomically, we ignore that path for now. |
5303 | * Otherwise, whine if we are scheduling when we should not be. | |
5304 | */ | |
3f33a7ce | 5305 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
5306 | __schedule_bug(prev); |
5307 | ||
1da177e4 LT |
5308 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
5309 | ||
2d72376b | 5310 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
5311 | #ifdef CONFIG_SCHEDSTATS |
5312 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
5313 | schedstat_inc(this_rq(), bkl_count); |
5314 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
5315 | } |
5316 | #endif | |
dd41f596 IM |
5317 | } |
5318 | ||
df1c99d4 MG |
5319 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
5320 | { | |
5321 | if (prev->state == TASK_RUNNING) { | |
5322 | u64 runtime = prev->se.sum_exec_runtime; | |
5323 | ||
5324 | runtime -= prev->se.prev_sum_exec_runtime; | |
5325 | runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); | |
5326 | ||
5327 | /* | |
5328 | * In order to avoid avg_overlap growing stale when we are | |
5329 | * indeed overlapping and hence not getting put to sleep, grow | |
5330 | * the avg_overlap on preemption. | |
5331 | * | |
5332 | * We use the average preemption runtime because that | |
5333 | * correlates to the amount of cache footprint a task can | |
5334 | * build up. | |
5335 | */ | |
5336 | update_avg(&prev->se.avg_overlap, runtime); | |
5337 | } | |
5338 | prev->sched_class->put_prev_task(rq, prev); | |
5339 | } | |
5340 | ||
dd41f596 IM |
5341 | /* |
5342 | * Pick up the highest-prio task: | |
5343 | */ | |
5344 | static inline struct task_struct * | |
b67802ea | 5345 | pick_next_task(struct rq *rq) |
dd41f596 | 5346 | { |
5522d5d5 | 5347 | const struct sched_class *class; |
dd41f596 | 5348 | struct task_struct *p; |
1da177e4 LT |
5349 | |
5350 | /* | |
dd41f596 IM |
5351 | * Optimization: we know that if all tasks are in |
5352 | * the fair class we can call that function directly: | |
1da177e4 | 5353 | */ |
dd41f596 | 5354 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 5355 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
5356 | if (likely(p)) |
5357 | return p; | |
1da177e4 LT |
5358 | } |
5359 | ||
dd41f596 IM |
5360 | class = sched_class_highest; |
5361 | for ( ; ; ) { | |
fb8d4724 | 5362 | p = class->pick_next_task(rq); |
dd41f596 IM |
5363 | if (p) |
5364 | return p; | |
5365 | /* | |
5366 | * Will never be NULL as the idle class always | |
5367 | * returns a non-NULL p: | |
5368 | */ | |
5369 | class = class->next; | |
5370 | } | |
5371 | } | |
1da177e4 | 5372 | |
dd41f596 IM |
5373 | /* |
5374 | * schedule() is the main scheduler function. | |
5375 | */ | |
ff743345 | 5376 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
5377 | { |
5378 | struct task_struct *prev, *next; | |
67ca7bde | 5379 | unsigned long *switch_count; |
dd41f596 | 5380 | struct rq *rq; |
31656519 | 5381 | int cpu; |
dd41f596 | 5382 | |
ff743345 PZ |
5383 | need_resched: |
5384 | preempt_disable(); | |
dd41f596 IM |
5385 | cpu = smp_processor_id(); |
5386 | rq = cpu_rq(cpu); | |
d6714c22 | 5387 | rcu_sched_qs(cpu); |
dd41f596 IM |
5388 | prev = rq->curr; |
5389 | switch_count = &prev->nivcsw; | |
5390 | ||
5391 | release_kernel_lock(prev); | |
5392 | need_resched_nonpreemptible: | |
5393 | ||
5394 | schedule_debug(prev); | |
1da177e4 | 5395 | |
31656519 | 5396 | if (sched_feat(HRTICK)) |
f333fdc9 | 5397 | hrtick_clear(rq); |
8f4d37ec | 5398 | |
8cd162ce | 5399 | spin_lock_irq(&rq->lock); |
3e51f33f | 5400 | update_rq_clock(rq); |
1e819950 | 5401 | clear_tsk_need_resched(prev); |
1da177e4 | 5402 | |
1da177e4 | 5403 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 5404 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 5405 | prev->state = TASK_RUNNING; |
16882c1e | 5406 | else |
2e1cb74a | 5407 | deactivate_task(rq, prev, 1); |
dd41f596 | 5408 | switch_count = &prev->nvcsw; |
1da177e4 LT |
5409 | } |
5410 | ||
3f029d3c | 5411 | pre_schedule(rq, prev); |
f65eda4f | 5412 | |
dd41f596 | 5413 | if (unlikely(!rq->nr_running)) |
1da177e4 | 5414 | idle_balance(cpu, rq); |
1da177e4 | 5415 | |
df1c99d4 | 5416 | put_prev_task(rq, prev); |
b67802ea | 5417 | next = pick_next_task(rq); |
1da177e4 | 5418 | |
1da177e4 | 5419 | if (likely(prev != next)) { |
673a90a1 | 5420 | sched_info_switch(prev, next); |
564c2b21 | 5421 | perf_counter_task_sched_out(prev, next, cpu); |
673a90a1 | 5422 | |
1da177e4 LT |
5423 | rq->nr_switches++; |
5424 | rq->curr = next; | |
5425 | ++*switch_count; | |
5426 | ||
dd41f596 | 5427 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
5428 | /* |
5429 | * the context switch might have flipped the stack from under | |
5430 | * us, hence refresh the local variables. | |
5431 | */ | |
5432 | cpu = smp_processor_id(); | |
5433 | rq = cpu_rq(cpu); | |
1da177e4 LT |
5434 | } else |
5435 | spin_unlock_irq(&rq->lock); | |
5436 | ||
3f029d3c | 5437 | post_schedule(rq); |
1da177e4 | 5438 | |
8f4d37ec | 5439 | if (unlikely(reacquire_kernel_lock(current) < 0)) |
1da177e4 | 5440 | goto need_resched_nonpreemptible; |
8f4d37ec | 5441 | |
1da177e4 | 5442 | preempt_enable_no_resched(); |
ff743345 | 5443 | if (need_resched()) |
1da177e4 LT |
5444 | goto need_resched; |
5445 | } | |
1da177e4 LT |
5446 | EXPORT_SYMBOL(schedule); |
5447 | ||
0d66bf6d PZ |
5448 | #ifdef CONFIG_SMP |
5449 | /* | |
5450 | * Look out! "owner" is an entirely speculative pointer | |
5451 | * access and not reliable. | |
5452 | */ | |
5453 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
5454 | { | |
5455 | unsigned int cpu; | |
5456 | struct rq *rq; | |
5457 | ||
5458 | if (!sched_feat(OWNER_SPIN)) | |
5459 | return 0; | |
5460 | ||
5461 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
5462 | /* | |
5463 | * Need to access the cpu field knowing that | |
5464 | * DEBUG_PAGEALLOC could have unmapped it if | |
5465 | * the mutex owner just released it and exited. | |
5466 | */ | |
5467 | if (probe_kernel_address(&owner->cpu, cpu)) | |
5468 | goto out; | |
5469 | #else | |
5470 | cpu = owner->cpu; | |
5471 | #endif | |
5472 | ||
5473 | /* | |
5474 | * Even if the access succeeded (likely case), | |
5475 | * the cpu field may no longer be valid. | |
5476 | */ | |
5477 | if (cpu >= nr_cpumask_bits) | |
5478 | goto out; | |
5479 | ||
5480 | /* | |
5481 | * We need to validate that we can do a | |
5482 | * get_cpu() and that we have the percpu area. | |
5483 | */ | |
5484 | if (!cpu_online(cpu)) | |
5485 | goto out; | |
5486 | ||
5487 | rq = cpu_rq(cpu); | |
5488 | ||
5489 | for (;;) { | |
5490 | /* | |
5491 | * Owner changed, break to re-assess state. | |
5492 | */ | |
5493 | if (lock->owner != owner) | |
5494 | break; | |
5495 | ||
5496 | /* | |
5497 | * Is that owner really running on that cpu? | |
5498 | */ | |
5499 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
5500 | return 0; | |
5501 | ||
5502 | cpu_relax(); | |
5503 | } | |
5504 | out: | |
5505 | return 1; | |
5506 | } | |
5507 | #endif | |
5508 | ||
1da177e4 LT |
5509 | #ifdef CONFIG_PREEMPT |
5510 | /* | |
2ed6e34f | 5511 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 5512 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
5513 | * occur there and call schedule directly. |
5514 | */ | |
5515 | asmlinkage void __sched preempt_schedule(void) | |
5516 | { | |
5517 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 5518 | |
1da177e4 LT |
5519 | /* |
5520 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 5521 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 5522 | */ |
beed33a8 | 5523 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
5524 | return; |
5525 | ||
3a5c359a AK |
5526 | do { |
5527 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 5528 | schedule(); |
3a5c359a | 5529 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 5530 | |
3a5c359a AK |
5531 | /* |
5532 | * Check again in case we missed a preemption opportunity | |
5533 | * between schedule and now. | |
5534 | */ | |
5535 | barrier(); | |
5ed0cec0 | 5536 | } while (need_resched()); |
1da177e4 | 5537 | } |
1da177e4 LT |
5538 | EXPORT_SYMBOL(preempt_schedule); |
5539 | ||
5540 | /* | |
2ed6e34f | 5541 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
5542 | * off of irq context. |
5543 | * Note, that this is called and return with irqs disabled. This will | |
5544 | * protect us against recursive calling from irq. | |
5545 | */ | |
5546 | asmlinkage void __sched preempt_schedule_irq(void) | |
5547 | { | |
5548 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 5549 | |
2ed6e34f | 5550 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
5551 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
5552 | ||
3a5c359a AK |
5553 | do { |
5554 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
5555 | local_irq_enable(); |
5556 | schedule(); | |
5557 | local_irq_disable(); | |
3a5c359a | 5558 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 5559 | |
3a5c359a AK |
5560 | /* |
5561 | * Check again in case we missed a preemption opportunity | |
5562 | * between schedule and now. | |
5563 | */ | |
5564 | barrier(); | |
5ed0cec0 | 5565 | } while (need_resched()); |
1da177e4 LT |
5566 | } |
5567 | ||
5568 | #endif /* CONFIG_PREEMPT */ | |
5569 | ||
95cdf3b7 IM |
5570 | int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, |
5571 | void *key) | |
1da177e4 | 5572 | { |
48f24c4d | 5573 | return try_to_wake_up(curr->private, mode, sync); |
1da177e4 | 5574 | } |
1da177e4 LT |
5575 | EXPORT_SYMBOL(default_wake_function); |
5576 | ||
5577 | /* | |
41a2d6cf IM |
5578 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
5579 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
5580 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
5581 | * | |
5582 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 5583 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
5584 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
5585 | */ | |
78ddb08f | 5586 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
777c6c5f | 5587 | int nr_exclusive, int sync, void *key) |
1da177e4 | 5588 | { |
2e45874c | 5589 | wait_queue_t *curr, *next; |
1da177e4 | 5590 | |
2e45874c | 5591 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
5592 | unsigned flags = curr->flags; |
5593 | ||
1da177e4 | 5594 | if (curr->func(curr, mode, sync, key) && |
48f24c4d | 5595 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
5596 | break; |
5597 | } | |
5598 | } | |
5599 | ||
5600 | /** | |
5601 | * __wake_up - wake up threads blocked on a waitqueue. | |
5602 | * @q: the waitqueue | |
5603 | * @mode: which threads | |
5604 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 5605 | * @key: is directly passed to the wakeup function |
50fa610a DH |
5606 | * |
5607 | * It may be assumed that this function implies a write memory barrier before | |
5608 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 5609 | */ |
7ad5b3a5 | 5610 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 5611 | int nr_exclusive, void *key) |
1da177e4 LT |
5612 | { |
5613 | unsigned long flags; | |
5614 | ||
5615 | spin_lock_irqsave(&q->lock, flags); | |
5616 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
5617 | spin_unlock_irqrestore(&q->lock, flags); | |
5618 | } | |
1da177e4 LT |
5619 | EXPORT_SYMBOL(__wake_up); |
5620 | ||
5621 | /* | |
5622 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
5623 | */ | |
7ad5b3a5 | 5624 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
5625 | { |
5626 | __wake_up_common(q, mode, 1, 0, NULL); | |
5627 | } | |
5628 | ||
4ede816a DL |
5629 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
5630 | { | |
5631 | __wake_up_common(q, mode, 1, 0, key); | |
5632 | } | |
5633 | ||
1da177e4 | 5634 | /** |
4ede816a | 5635 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
5636 | * @q: the waitqueue |
5637 | * @mode: which threads | |
5638 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 5639 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
5640 | * |
5641 | * The sync wakeup differs that the waker knows that it will schedule | |
5642 | * away soon, so while the target thread will be woken up, it will not | |
5643 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
5644 | * with each other. This can prevent needless bouncing between CPUs. | |
5645 | * | |
5646 | * On UP it can prevent extra preemption. | |
50fa610a DH |
5647 | * |
5648 | * It may be assumed that this function implies a write memory barrier before | |
5649 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 5650 | */ |
4ede816a DL |
5651 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
5652 | int nr_exclusive, void *key) | |
1da177e4 LT |
5653 | { |
5654 | unsigned long flags; | |
5655 | int sync = 1; | |
5656 | ||
5657 | if (unlikely(!q)) | |
5658 | return; | |
5659 | ||
5660 | if (unlikely(!nr_exclusive)) | |
5661 | sync = 0; | |
5662 | ||
5663 | spin_lock_irqsave(&q->lock, flags); | |
4ede816a | 5664 | __wake_up_common(q, mode, nr_exclusive, sync, key); |
1da177e4 LT |
5665 | spin_unlock_irqrestore(&q->lock, flags); |
5666 | } | |
4ede816a DL |
5667 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
5668 | ||
5669 | /* | |
5670 | * __wake_up_sync - see __wake_up_sync_key() | |
5671 | */ | |
5672 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
5673 | { | |
5674 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
5675 | } | |
1da177e4 LT |
5676 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
5677 | ||
65eb3dc6 KD |
5678 | /** |
5679 | * complete: - signals a single thread waiting on this completion | |
5680 | * @x: holds the state of this particular completion | |
5681 | * | |
5682 | * This will wake up a single thread waiting on this completion. Threads will be | |
5683 | * awakened in the same order in which they were queued. | |
5684 | * | |
5685 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
5686 | * |
5687 | * It may be assumed that this function implies a write memory barrier before | |
5688 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 5689 | */ |
b15136e9 | 5690 | void complete(struct completion *x) |
1da177e4 LT |
5691 | { |
5692 | unsigned long flags; | |
5693 | ||
5694 | spin_lock_irqsave(&x->wait.lock, flags); | |
5695 | x->done++; | |
d9514f6c | 5696 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
5697 | spin_unlock_irqrestore(&x->wait.lock, flags); |
5698 | } | |
5699 | EXPORT_SYMBOL(complete); | |
5700 | ||
65eb3dc6 KD |
5701 | /** |
5702 | * complete_all: - signals all threads waiting on this completion | |
5703 | * @x: holds the state of this particular completion | |
5704 | * | |
5705 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
5706 | * |
5707 | * It may be assumed that this function implies a write memory barrier before | |
5708 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 5709 | */ |
b15136e9 | 5710 | void complete_all(struct completion *x) |
1da177e4 LT |
5711 | { |
5712 | unsigned long flags; | |
5713 | ||
5714 | spin_lock_irqsave(&x->wait.lock, flags); | |
5715 | x->done += UINT_MAX/2; | |
d9514f6c | 5716 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
5717 | spin_unlock_irqrestore(&x->wait.lock, flags); |
5718 | } | |
5719 | EXPORT_SYMBOL(complete_all); | |
5720 | ||
8cbbe86d AK |
5721 | static inline long __sched |
5722 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 5723 | { |
1da177e4 LT |
5724 | if (!x->done) { |
5725 | DECLARE_WAITQUEUE(wait, current); | |
5726 | ||
5727 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
5728 | __add_wait_queue_tail(&x->wait, &wait); | |
5729 | do { | |
94d3d824 | 5730 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
5731 | timeout = -ERESTARTSYS; |
5732 | break; | |
8cbbe86d AK |
5733 | } |
5734 | __set_current_state(state); | |
1da177e4 LT |
5735 | spin_unlock_irq(&x->wait.lock); |
5736 | timeout = schedule_timeout(timeout); | |
5737 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 5738 | } while (!x->done && timeout); |
1da177e4 | 5739 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
5740 | if (!x->done) |
5741 | return timeout; | |
1da177e4 LT |
5742 | } |
5743 | x->done--; | |
ea71a546 | 5744 | return timeout ?: 1; |
1da177e4 | 5745 | } |
1da177e4 | 5746 | |
8cbbe86d AK |
5747 | static long __sched |
5748 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 5749 | { |
1da177e4 LT |
5750 | might_sleep(); |
5751 | ||
5752 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 5753 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 5754 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
5755 | return timeout; |
5756 | } | |
1da177e4 | 5757 | |
65eb3dc6 KD |
5758 | /** |
5759 | * wait_for_completion: - waits for completion of a task | |
5760 | * @x: holds the state of this particular completion | |
5761 | * | |
5762 | * This waits to be signaled for completion of a specific task. It is NOT | |
5763 | * interruptible and there is no timeout. | |
5764 | * | |
5765 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
5766 | * and interrupt capability. Also see complete(). | |
5767 | */ | |
b15136e9 | 5768 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
5769 | { |
5770 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 5771 | } |
8cbbe86d | 5772 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 5773 | |
65eb3dc6 KD |
5774 | /** |
5775 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
5776 | * @x: holds the state of this particular completion | |
5777 | * @timeout: timeout value in jiffies | |
5778 | * | |
5779 | * This waits for either a completion of a specific task to be signaled or for a | |
5780 | * specified timeout to expire. The timeout is in jiffies. It is not | |
5781 | * interruptible. | |
5782 | */ | |
b15136e9 | 5783 | unsigned long __sched |
8cbbe86d | 5784 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 5785 | { |
8cbbe86d | 5786 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 5787 | } |
8cbbe86d | 5788 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 5789 | |
65eb3dc6 KD |
5790 | /** |
5791 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
5792 | * @x: holds the state of this particular completion | |
5793 | * | |
5794 | * This waits for completion of a specific task to be signaled. It is | |
5795 | * interruptible. | |
5796 | */ | |
8cbbe86d | 5797 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 5798 | { |
51e97990 AK |
5799 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
5800 | if (t == -ERESTARTSYS) | |
5801 | return t; | |
5802 | return 0; | |
0fec171c | 5803 | } |
8cbbe86d | 5804 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 5805 | |
65eb3dc6 KD |
5806 | /** |
5807 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
5808 | * @x: holds the state of this particular completion | |
5809 | * @timeout: timeout value in jiffies | |
5810 | * | |
5811 | * This waits for either a completion of a specific task to be signaled or for a | |
5812 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
5813 | */ | |
b15136e9 | 5814 | unsigned long __sched |
8cbbe86d AK |
5815 | wait_for_completion_interruptible_timeout(struct completion *x, |
5816 | unsigned long timeout) | |
0fec171c | 5817 | { |
8cbbe86d | 5818 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 5819 | } |
8cbbe86d | 5820 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 5821 | |
65eb3dc6 KD |
5822 | /** |
5823 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
5824 | * @x: holds the state of this particular completion | |
5825 | * | |
5826 | * This waits to be signaled for completion of a specific task. It can be | |
5827 | * interrupted by a kill signal. | |
5828 | */ | |
009e577e MW |
5829 | int __sched wait_for_completion_killable(struct completion *x) |
5830 | { | |
5831 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
5832 | if (t == -ERESTARTSYS) | |
5833 | return t; | |
5834 | return 0; | |
5835 | } | |
5836 | EXPORT_SYMBOL(wait_for_completion_killable); | |
5837 | ||
be4de352 DC |
5838 | /** |
5839 | * try_wait_for_completion - try to decrement a completion without blocking | |
5840 | * @x: completion structure | |
5841 | * | |
5842 | * Returns: 0 if a decrement cannot be done without blocking | |
5843 | * 1 if a decrement succeeded. | |
5844 | * | |
5845 | * If a completion is being used as a counting completion, | |
5846 | * attempt to decrement the counter without blocking. This | |
5847 | * enables us to avoid waiting if the resource the completion | |
5848 | * is protecting is not available. | |
5849 | */ | |
5850 | bool try_wait_for_completion(struct completion *x) | |
5851 | { | |
5852 | int ret = 1; | |
5853 | ||
5854 | spin_lock_irq(&x->wait.lock); | |
5855 | if (!x->done) | |
5856 | ret = 0; | |
5857 | else | |
5858 | x->done--; | |
5859 | spin_unlock_irq(&x->wait.lock); | |
5860 | return ret; | |
5861 | } | |
5862 | EXPORT_SYMBOL(try_wait_for_completion); | |
5863 | ||
5864 | /** | |
5865 | * completion_done - Test to see if a completion has any waiters | |
5866 | * @x: completion structure | |
5867 | * | |
5868 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
5869 | * 1 if there are no waiters. | |
5870 | * | |
5871 | */ | |
5872 | bool completion_done(struct completion *x) | |
5873 | { | |
5874 | int ret = 1; | |
5875 | ||
5876 | spin_lock_irq(&x->wait.lock); | |
5877 | if (!x->done) | |
5878 | ret = 0; | |
5879 | spin_unlock_irq(&x->wait.lock); | |
5880 | return ret; | |
5881 | } | |
5882 | EXPORT_SYMBOL(completion_done); | |
5883 | ||
8cbbe86d AK |
5884 | static long __sched |
5885 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 5886 | { |
0fec171c IM |
5887 | unsigned long flags; |
5888 | wait_queue_t wait; | |
5889 | ||
5890 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 5891 | |
8cbbe86d | 5892 | __set_current_state(state); |
1da177e4 | 5893 | |
8cbbe86d AK |
5894 | spin_lock_irqsave(&q->lock, flags); |
5895 | __add_wait_queue(q, &wait); | |
5896 | spin_unlock(&q->lock); | |
5897 | timeout = schedule_timeout(timeout); | |
5898 | spin_lock_irq(&q->lock); | |
5899 | __remove_wait_queue(q, &wait); | |
5900 | spin_unlock_irqrestore(&q->lock, flags); | |
5901 | ||
5902 | return timeout; | |
5903 | } | |
5904 | ||
5905 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
5906 | { | |
5907 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 5908 | } |
1da177e4 LT |
5909 | EXPORT_SYMBOL(interruptible_sleep_on); |
5910 | ||
0fec171c | 5911 | long __sched |
95cdf3b7 | 5912 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 5913 | { |
8cbbe86d | 5914 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 5915 | } |
1da177e4 LT |
5916 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
5917 | ||
0fec171c | 5918 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 5919 | { |
8cbbe86d | 5920 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 5921 | } |
1da177e4 LT |
5922 | EXPORT_SYMBOL(sleep_on); |
5923 | ||
0fec171c | 5924 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 5925 | { |
8cbbe86d | 5926 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 5927 | } |
1da177e4 LT |
5928 | EXPORT_SYMBOL(sleep_on_timeout); |
5929 | ||
b29739f9 IM |
5930 | #ifdef CONFIG_RT_MUTEXES |
5931 | ||
5932 | /* | |
5933 | * rt_mutex_setprio - set the current priority of a task | |
5934 | * @p: task | |
5935 | * @prio: prio value (kernel-internal form) | |
5936 | * | |
5937 | * This function changes the 'effective' priority of a task. It does | |
5938 | * not touch ->normal_prio like __setscheduler(). | |
5939 | * | |
5940 | * Used by the rt_mutex code to implement priority inheritance logic. | |
5941 | */ | |
36c8b586 | 5942 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
5943 | { |
5944 | unsigned long flags; | |
83b699ed | 5945 | int oldprio, on_rq, running; |
70b97a7f | 5946 | struct rq *rq; |
cb469845 | 5947 | const struct sched_class *prev_class = p->sched_class; |
b29739f9 IM |
5948 | |
5949 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
5950 | ||
5951 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 5952 | update_rq_clock(rq); |
b29739f9 | 5953 | |
d5f9f942 | 5954 | oldprio = p->prio; |
dd41f596 | 5955 | on_rq = p->se.on_rq; |
051a1d1a | 5956 | running = task_current(rq, p); |
0e1f3483 | 5957 | if (on_rq) |
69be72c1 | 5958 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
5959 | if (running) |
5960 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
5961 | |
5962 | if (rt_prio(prio)) | |
5963 | p->sched_class = &rt_sched_class; | |
5964 | else | |
5965 | p->sched_class = &fair_sched_class; | |
5966 | ||
b29739f9 IM |
5967 | p->prio = prio; |
5968 | ||
0e1f3483 HS |
5969 | if (running) |
5970 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 5971 | if (on_rq) { |
8159f87e | 5972 | enqueue_task(rq, p, 0); |
cb469845 SR |
5973 | |
5974 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
5975 | } |
5976 | task_rq_unlock(rq, &flags); | |
5977 | } | |
5978 | ||
5979 | #endif | |
5980 | ||
36c8b586 | 5981 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 5982 | { |
dd41f596 | 5983 | int old_prio, delta, on_rq; |
1da177e4 | 5984 | unsigned long flags; |
70b97a7f | 5985 | struct rq *rq; |
1da177e4 LT |
5986 | |
5987 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
5988 | return; | |
5989 | /* | |
5990 | * We have to be careful, if called from sys_setpriority(), | |
5991 | * the task might be in the middle of scheduling on another CPU. | |
5992 | */ | |
5993 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 5994 | update_rq_clock(rq); |
1da177e4 LT |
5995 | /* |
5996 | * The RT priorities are set via sched_setscheduler(), but we still | |
5997 | * allow the 'normal' nice value to be set - but as expected | |
5998 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 5999 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 6000 | */ |
e05606d3 | 6001 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
6002 | p->static_prio = NICE_TO_PRIO(nice); |
6003 | goto out_unlock; | |
6004 | } | |
dd41f596 | 6005 | on_rq = p->se.on_rq; |
c09595f6 | 6006 | if (on_rq) |
69be72c1 | 6007 | dequeue_task(rq, p, 0); |
1da177e4 | 6008 | |
1da177e4 | 6009 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 6010 | set_load_weight(p); |
b29739f9 IM |
6011 | old_prio = p->prio; |
6012 | p->prio = effective_prio(p); | |
6013 | delta = p->prio - old_prio; | |
1da177e4 | 6014 | |
dd41f596 | 6015 | if (on_rq) { |
8159f87e | 6016 | enqueue_task(rq, p, 0); |
1da177e4 | 6017 | /* |
d5f9f942 AM |
6018 | * If the task increased its priority or is running and |
6019 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 6020 | */ |
d5f9f942 | 6021 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
6022 | resched_task(rq->curr); |
6023 | } | |
6024 | out_unlock: | |
6025 | task_rq_unlock(rq, &flags); | |
6026 | } | |
1da177e4 LT |
6027 | EXPORT_SYMBOL(set_user_nice); |
6028 | ||
e43379f1 MM |
6029 | /* |
6030 | * can_nice - check if a task can reduce its nice value | |
6031 | * @p: task | |
6032 | * @nice: nice value | |
6033 | */ | |
36c8b586 | 6034 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 6035 | { |
024f4747 MM |
6036 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
6037 | int nice_rlim = 20 - nice; | |
48f24c4d | 6038 | |
e43379f1 MM |
6039 | return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || |
6040 | capable(CAP_SYS_NICE)); | |
6041 | } | |
6042 | ||
1da177e4 LT |
6043 | #ifdef __ARCH_WANT_SYS_NICE |
6044 | ||
6045 | /* | |
6046 | * sys_nice - change the priority of the current process. | |
6047 | * @increment: priority increment | |
6048 | * | |
6049 | * sys_setpriority is a more generic, but much slower function that | |
6050 | * does similar things. | |
6051 | */ | |
5add95d4 | 6052 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 6053 | { |
48f24c4d | 6054 | long nice, retval; |
1da177e4 LT |
6055 | |
6056 | /* | |
6057 | * Setpriority might change our priority at the same moment. | |
6058 | * We don't have to worry. Conceptually one call occurs first | |
6059 | * and we have a single winner. | |
6060 | */ | |
e43379f1 MM |
6061 | if (increment < -40) |
6062 | increment = -40; | |
1da177e4 LT |
6063 | if (increment > 40) |
6064 | increment = 40; | |
6065 | ||
2b8f836f | 6066 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
6067 | if (nice < -20) |
6068 | nice = -20; | |
6069 | if (nice > 19) | |
6070 | nice = 19; | |
6071 | ||
e43379f1 MM |
6072 | if (increment < 0 && !can_nice(current, nice)) |
6073 | return -EPERM; | |
6074 | ||
1da177e4 LT |
6075 | retval = security_task_setnice(current, nice); |
6076 | if (retval) | |
6077 | return retval; | |
6078 | ||
6079 | set_user_nice(current, nice); | |
6080 | return 0; | |
6081 | } | |
6082 | ||
6083 | #endif | |
6084 | ||
6085 | /** | |
6086 | * task_prio - return the priority value of a given task. | |
6087 | * @p: the task in question. | |
6088 | * | |
6089 | * This is the priority value as seen by users in /proc. | |
6090 | * RT tasks are offset by -200. Normal tasks are centered | |
6091 | * around 0, value goes from -16 to +15. | |
6092 | */ | |
36c8b586 | 6093 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
6094 | { |
6095 | return p->prio - MAX_RT_PRIO; | |
6096 | } | |
6097 | ||
6098 | /** | |
6099 | * task_nice - return the nice value of a given task. | |
6100 | * @p: the task in question. | |
6101 | */ | |
36c8b586 | 6102 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
6103 | { |
6104 | return TASK_NICE(p); | |
6105 | } | |
150d8bed | 6106 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
6107 | |
6108 | /** | |
6109 | * idle_cpu - is a given cpu idle currently? | |
6110 | * @cpu: the processor in question. | |
6111 | */ | |
6112 | int idle_cpu(int cpu) | |
6113 | { | |
6114 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
6115 | } | |
6116 | ||
1da177e4 LT |
6117 | /** |
6118 | * idle_task - return the idle task for a given cpu. | |
6119 | * @cpu: the processor in question. | |
6120 | */ | |
36c8b586 | 6121 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
6122 | { |
6123 | return cpu_rq(cpu)->idle; | |
6124 | } | |
6125 | ||
6126 | /** | |
6127 | * find_process_by_pid - find a process with a matching PID value. | |
6128 | * @pid: the pid in question. | |
6129 | */ | |
a9957449 | 6130 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 6131 | { |
228ebcbe | 6132 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
6133 | } |
6134 | ||
6135 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
6136 | static void |
6137 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 6138 | { |
dd41f596 | 6139 | BUG_ON(p->se.on_rq); |
48f24c4d | 6140 | |
1da177e4 | 6141 | p->policy = policy; |
dd41f596 IM |
6142 | switch (p->policy) { |
6143 | case SCHED_NORMAL: | |
6144 | case SCHED_BATCH: | |
6145 | case SCHED_IDLE: | |
6146 | p->sched_class = &fair_sched_class; | |
6147 | break; | |
6148 | case SCHED_FIFO: | |
6149 | case SCHED_RR: | |
6150 | p->sched_class = &rt_sched_class; | |
6151 | break; | |
6152 | } | |
6153 | ||
1da177e4 | 6154 | p->rt_priority = prio; |
b29739f9 IM |
6155 | p->normal_prio = normal_prio(p); |
6156 | /* we are holding p->pi_lock already */ | |
6157 | p->prio = rt_mutex_getprio(p); | |
2dd73a4f | 6158 | set_load_weight(p); |
1da177e4 LT |
6159 | } |
6160 | ||
c69e8d9c DH |
6161 | /* |
6162 | * check the target process has a UID that matches the current process's | |
6163 | */ | |
6164 | static bool check_same_owner(struct task_struct *p) | |
6165 | { | |
6166 | const struct cred *cred = current_cred(), *pcred; | |
6167 | bool match; | |
6168 | ||
6169 | rcu_read_lock(); | |
6170 | pcred = __task_cred(p); | |
6171 | match = (cred->euid == pcred->euid || | |
6172 | cred->euid == pcred->uid); | |
6173 | rcu_read_unlock(); | |
6174 | return match; | |
6175 | } | |
6176 | ||
961ccddd RR |
6177 | static int __sched_setscheduler(struct task_struct *p, int policy, |
6178 | struct sched_param *param, bool user) | |
1da177e4 | 6179 | { |
83b699ed | 6180 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 6181 | unsigned long flags; |
cb469845 | 6182 | const struct sched_class *prev_class = p->sched_class; |
70b97a7f | 6183 | struct rq *rq; |
ca94c442 | 6184 | int reset_on_fork; |
1da177e4 | 6185 | |
66e5393a SR |
6186 | /* may grab non-irq protected spin_locks */ |
6187 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
6188 | recheck: |
6189 | /* double check policy once rq lock held */ | |
ca94c442 LP |
6190 | if (policy < 0) { |
6191 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 6192 | policy = oldpolicy = p->policy; |
ca94c442 LP |
6193 | } else { |
6194 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
6195 | policy &= ~SCHED_RESET_ON_FORK; | |
6196 | ||
6197 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
6198 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
6199 | policy != SCHED_IDLE) | |
6200 | return -EINVAL; | |
6201 | } | |
6202 | ||
1da177e4 LT |
6203 | /* |
6204 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
6205 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
6206 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
6207 | */ |
6208 | if (param->sched_priority < 0 || | |
95cdf3b7 | 6209 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 6210 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 6211 | return -EINVAL; |
e05606d3 | 6212 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
6213 | return -EINVAL; |
6214 | ||
37e4ab3f OC |
6215 | /* |
6216 | * Allow unprivileged RT tasks to decrease priority: | |
6217 | */ | |
961ccddd | 6218 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 6219 | if (rt_policy(policy)) { |
8dc3e909 | 6220 | unsigned long rlim_rtprio; |
8dc3e909 ON |
6221 | |
6222 | if (!lock_task_sighand(p, &flags)) | |
6223 | return -ESRCH; | |
6224 | rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; | |
6225 | unlock_task_sighand(p, &flags); | |
6226 | ||
6227 | /* can't set/change the rt policy */ | |
6228 | if (policy != p->policy && !rlim_rtprio) | |
6229 | return -EPERM; | |
6230 | ||
6231 | /* can't increase priority */ | |
6232 | if (param->sched_priority > p->rt_priority && | |
6233 | param->sched_priority > rlim_rtprio) | |
6234 | return -EPERM; | |
6235 | } | |
dd41f596 IM |
6236 | /* |
6237 | * Like positive nice levels, dont allow tasks to | |
6238 | * move out of SCHED_IDLE either: | |
6239 | */ | |
6240 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
6241 | return -EPERM; | |
5fe1d75f | 6242 | |
37e4ab3f | 6243 | /* can't change other user's priorities */ |
c69e8d9c | 6244 | if (!check_same_owner(p)) |
37e4ab3f | 6245 | return -EPERM; |
ca94c442 LP |
6246 | |
6247 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
6248 | if (p->sched_reset_on_fork && !reset_on_fork) | |
6249 | return -EPERM; | |
37e4ab3f | 6250 | } |
1da177e4 | 6251 | |
725aad24 | 6252 | if (user) { |
b68aa230 | 6253 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
6254 | /* |
6255 | * Do not allow realtime tasks into groups that have no runtime | |
6256 | * assigned. | |
6257 | */ | |
9a7e0b18 PZ |
6258 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
6259 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 6260 | return -EPERM; |
b68aa230 PZ |
6261 | #endif |
6262 | ||
725aad24 JF |
6263 | retval = security_task_setscheduler(p, policy, param); |
6264 | if (retval) | |
6265 | return retval; | |
6266 | } | |
6267 | ||
b29739f9 IM |
6268 | /* |
6269 | * make sure no PI-waiters arrive (or leave) while we are | |
6270 | * changing the priority of the task: | |
6271 | */ | |
6272 | spin_lock_irqsave(&p->pi_lock, flags); | |
1da177e4 LT |
6273 | /* |
6274 | * To be able to change p->policy safely, the apropriate | |
6275 | * runqueue lock must be held. | |
6276 | */ | |
b29739f9 | 6277 | rq = __task_rq_lock(p); |
1da177e4 LT |
6278 | /* recheck policy now with rq lock held */ |
6279 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
6280 | policy = oldpolicy = -1; | |
b29739f9 IM |
6281 | __task_rq_unlock(rq); |
6282 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
1da177e4 LT |
6283 | goto recheck; |
6284 | } | |
2daa3577 | 6285 | update_rq_clock(rq); |
dd41f596 | 6286 | on_rq = p->se.on_rq; |
051a1d1a | 6287 | running = task_current(rq, p); |
0e1f3483 | 6288 | if (on_rq) |
2e1cb74a | 6289 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
6290 | if (running) |
6291 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 6292 | |
ca94c442 LP |
6293 | p->sched_reset_on_fork = reset_on_fork; |
6294 | ||
1da177e4 | 6295 | oldprio = p->prio; |
dd41f596 | 6296 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 6297 | |
0e1f3483 HS |
6298 | if (running) |
6299 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
6300 | if (on_rq) { |
6301 | activate_task(rq, p, 0); | |
cb469845 SR |
6302 | |
6303 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 6304 | } |
b29739f9 IM |
6305 | __task_rq_unlock(rq); |
6306 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
6307 | ||
95e02ca9 TG |
6308 | rt_mutex_adjust_pi(p); |
6309 | ||
1da177e4 LT |
6310 | return 0; |
6311 | } | |
961ccddd RR |
6312 | |
6313 | /** | |
6314 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
6315 | * @p: the task in question. | |
6316 | * @policy: new policy. | |
6317 | * @param: structure containing the new RT priority. | |
6318 | * | |
6319 | * NOTE that the task may be already dead. | |
6320 | */ | |
6321 | int sched_setscheduler(struct task_struct *p, int policy, | |
6322 | struct sched_param *param) | |
6323 | { | |
6324 | return __sched_setscheduler(p, policy, param, true); | |
6325 | } | |
1da177e4 LT |
6326 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
6327 | ||
961ccddd RR |
6328 | /** |
6329 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
6330 | * @p: the task in question. | |
6331 | * @policy: new policy. | |
6332 | * @param: structure containing the new RT priority. | |
6333 | * | |
6334 | * Just like sched_setscheduler, only don't bother checking if the | |
6335 | * current context has permission. For example, this is needed in | |
6336 | * stop_machine(): we create temporary high priority worker threads, | |
6337 | * but our caller might not have that capability. | |
6338 | */ | |
6339 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
6340 | struct sched_param *param) | |
6341 | { | |
6342 | return __sched_setscheduler(p, policy, param, false); | |
6343 | } | |
6344 | ||
95cdf3b7 IM |
6345 | static int |
6346 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 6347 | { |
1da177e4 LT |
6348 | struct sched_param lparam; |
6349 | struct task_struct *p; | |
36c8b586 | 6350 | int retval; |
1da177e4 LT |
6351 | |
6352 | if (!param || pid < 0) | |
6353 | return -EINVAL; | |
6354 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
6355 | return -EFAULT; | |
5fe1d75f ON |
6356 | |
6357 | rcu_read_lock(); | |
6358 | retval = -ESRCH; | |
1da177e4 | 6359 | p = find_process_by_pid(pid); |
5fe1d75f ON |
6360 | if (p != NULL) |
6361 | retval = sched_setscheduler(p, policy, &lparam); | |
6362 | rcu_read_unlock(); | |
36c8b586 | 6363 | |
1da177e4 LT |
6364 | return retval; |
6365 | } | |
6366 | ||
6367 | /** | |
6368 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
6369 | * @pid: the pid in question. | |
6370 | * @policy: new policy. | |
6371 | * @param: structure containing the new RT priority. | |
6372 | */ | |
5add95d4 HC |
6373 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
6374 | struct sched_param __user *, param) | |
1da177e4 | 6375 | { |
c21761f1 JB |
6376 | /* negative values for policy are not valid */ |
6377 | if (policy < 0) | |
6378 | return -EINVAL; | |
6379 | ||
1da177e4 LT |
6380 | return do_sched_setscheduler(pid, policy, param); |
6381 | } | |
6382 | ||
6383 | /** | |
6384 | * sys_sched_setparam - set/change the RT priority of a thread | |
6385 | * @pid: the pid in question. | |
6386 | * @param: structure containing the new RT priority. | |
6387 | */ | |
5add95d4 | 6388 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
6389 | { |
6390 | return do_sched_setscheduler(pid, -1, param); | |
6391 | } | |
6392 | ||
6393 | /** | |
6394 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
6395 | * @pid: the pid in question. | |
6396 | */ | |
5add95d4 | 6397 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 6398 | { |
36c8b586 | 6399 | struct task_struct *p; |
3a5c359a | 6400 | int retval; |
1da177e4 LT |
6401 | |
6402 | if (pid < 0) | |
3a5c359a | 6403 | return -EINVAL; |
1da177e4 LT |
6404 | |
6405 | retval = -ESRCH; | |
6406 | read_lock(&tasklist_lock); | |
6407 | p = find_process_by_pid(pid); | |
6408 | if (p) { | |
6409 | retval = security_task_getscheduler(p); | |
6410 | if (!retval) | |
ca94c442 LP |
6411 | retval = p->policy |
6412 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 LT |
6413 | } |
6414 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
6415 | return retval; |
6416 | } | |
6417 | ||
6418 | /** | |
ca94c442 | 6419 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
6420 | * @pid: the pid in question. |
6421 | * @param: structure containing the RT priority. | |
6422 | */ | |
5add95d4 | 6423 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
6424 | { |
6425 | struct sched_param lp; | |
36c8b586 | 6426 | struct task_struct *p; |
3a5c359a | 6427 | int retval; |
1da177e4 LT |
6428 | |
6429 | if (!param || pid < 0) | |
3a5c359a | 6430 | return -EINVAL; |
1da177e4 LT |
6431 | |
6432 | read_lock(&tasklist_lock); | |
6433 | p = find_process_by_pid(pid); | |
6434 | retval = -ESRCH; | |
6435 | if (!p) | |
6436 | goto out_unlock; | |
6437 | ||
6438 | retval = security_task_getscheduler(p); | |
6439 | if (retval) | |
6440 | goto out_unlock; | |
6441 | ||
6442 | lp.sched_priority = p->rt_priority; | |
6443 | read_unlock(&tasklist_lock); | |
6444 | ||
6445 | /* | |
6446 | * This one might sleep, we cannot do it with a spinlock held ... | |
6447 | */ | |
6448 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
6449 | ||
1da177e4 LT |
6450 | return retval; |
6451 | ||
6452 | out_unlock: | |
6453 | read_unlock(&tasklist_lock); | |
6454 | return retval; | |
6455 | } | |
6456 | ||
96f874e2 | 6457 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 6458 | { |
5a16f3d3 | 6459 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
6460 | struct task_struct *p; |
6461 | int retval; | |
1da177e4 | 6462 | |
95402b38 | 6463 | get_online_cpus(); |
1da177e4 LT |
6464 | read_lock(&tasklist_lock); |
6465 | ||
6466 | p = find_process_by_pid(pid); | |
6467 | if (!p) { | |
6468 | read_unlock(&tasklist_lock); | |
95402b38 | 6469 | put_online_cpus(); |
1da177e4 LT |
6470 | return -ESRCH; |
6471 | } | |
6472 | ||
6473 | /* | |
6474 | * It is not safe to call set_cpus_allowed with the | |
41a2d6cf | 6475 | * tasklist_lock held. We will bump the task_struct's |
1da177e4 LT |
6476 | * usage count and then drop tasklist_lock. |
6477 | */ | |
6478 | get_task_struct(p); | |
6479 | read_unlock(&tasklist_lock); | |
6480 | ||
5a16f3d3 RR |
6481 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
6482 | retval = -ENOMEM; | |
6483 | goto out_put_task; | |
6484 | } | |
6485 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
6486 | retval = -ENOMEM; | |
6487 | goto out_free_cpus_allowed; | |
6488 | } | |
1da177e4 | 6489 | retval = -EPERM; |
c69e8d9c | 6490 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
6491 | goto out_unlock; |
6492 | ||
e7834f8f DQ |
6493 | retval = security_task_setscheduler(p, 0, NULL); |
6494 | if (retval) | |
6495 | goto out_unlock; | |
6496 | ||
5a16f3d3 RR |
6497 | cpuset_cpus_allowed(p, cpus_allowed); |
6498 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 6499 | again: |
5a16f3d3 | 6500 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 6501 | |
8707d8b8 | 6502 | if (!retval) { |
5a16f3d3 RR |
6503 | cpuset_cpus_allowed(p, cpus_allowed); |
6504 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
6505 | /* |
6506 | * We must have raced with a concurrent cpuset | |
6507 | * update. Just reset the cpus_allowed to the | |
6508 | * cpuset's cpus_allowed | |
6509 | */ | |
5a16f3d3 | 6510 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
6511 | goto again; |
6512 | } | |
6513 | } | |
1da177e4 | 6514 | out_unlock: |
5a16f3d3 RR |
6515 | free_cpumask_var(new_mask); |
6516 | out_free_cpus_allowed: | |
6517 | free_cpumask_var(cpus_allowed); | |
6518 | out_put_task: | |
1da177e4 | 6519 | put_task_struct(p); |
95402b38 | 6520 | put_online_cpus(); |
1da177e4 LT |
6521 | return retval; |
6522 | } | |
6523 | ||
6524 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 6525 | struct cpumask *new_mask) |
1da177e4 | 6526 | { |
96f874e2 RR |
6527 | if (len < cpumask_size()) |
6528 | cpumask_clear(new_mask); | |
6529 | else if (len > cpumask_size()) | |
6530 | len = cpumask_size(); | |
6531 | ||
1da177e4 LT |
6532 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
6533 | } | |
6534 | ||
6535 | /** | |
6536 | * sys_sched_setaffinity - set the cpu affinity of a process | |
6537 | * @pid: pid of the process | |
6538 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
6539 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
6540 | */ | |
5add95d4 HC |
6541 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
6542 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 6543 | { |
5a16f3d3 | 6544 | cpumask_var_t new_mask; |
1da177e4 LT |
6545 | int retval; |
6546 | ||
5a16f3d3 RR |
6547 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
6548 | return -ENOMEM; | |
1da177e4 | 6549 | |
5a16f3d3 RR |
6550 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
6551 | if (retval == 0) | |
6552 | retval = sched_setaffinity(pid, new_mask); | |
6553 | free_cpumask_var(new_mask); | |
6554 | return retval; | |
1da177e4 LT |
6555 | } |
6556 | ||
96f874e2 | 6557 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 6558 | { |
36c8b586 | 6559 | struct task_struct *p; |
1da177e4 | 6560 | int retval; |
1da177e4 | 6561 | |
95402b38 | 6562 | get_online_cpus(); |
1da177e4 LT |
6563 | read_lock(&tasklist_lock); |
6564 | ||
6565 | retval = -ESRCH; | |
6566 | p = find_process_by_pid(pid); | |
6567 | if (!p) | |
6568 | goto out_unlock; | |
6569 | ||
e7834f8f DQ |
6570 | retval = security_task_getscheduler(p); |
6571 | if (retval) | |
6572 | goto out_unlock; | |
6573 | ||
96f874e2 | 6574 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
1da177e4 LT |
6575 | |
6576 | out_unlock: | |
6577 | read_unlock(&tasklist_lock); | |
95402b38 | 6578 | put_online_cpus(); |
1da177e4 | 6579 | |
9531b62f | 6580 | return retval; |
1da177e4 LT |
6581 | } |
6582 | ||
6583 | /** | |
6584 | * sys_sched_getaffinity - get the cpu affinity of a process | |
6585 | * @pid: pid of the process | |
6586 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
6587 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
6588 | */ | |
5add95d4 HC |
6589 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
6590 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
6591 | { |
6592 | int ret; | |
f17c8607 | 6593 | cpumask_var_t mask; |
1da177e4 | 6594 | |
f17c8607 | 6595 | if (len < cpumask_size()) |
1da177e4 LT |
6596 | return -EINVAL; |
6597 | ||
f17c8607 RR |
6598 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
6599 | return -ENOMEM; | |
1da177e4 | 6600 | |
f17c8607 RR |
6601 | ret = sched_getaffinity(pid, mask); |
6602 | if (ret == 0) { | |
6603 | if (copy_to_user(user_mask_ptr, mask, cpumask_size())) | |
6604 | ret = -EFAULT; | |
6605 | else | |
6606 | ret = cpumask_size(); | |
6607 | } | |
6608 | free_cpumask_var(mask); | |
1da177e4 | 6609 | |
f17c8607 | 6610 | return ret; |
1da177e4 LT |
6611 | } |
6612 | ||
6613 | /** | |
6614 | * sys_sched_yield - yield the current processor to other threads. | |
6615 | * | |
dd41f596 IM |
6616 | * This function yields the current CPU to other tasks. If there are no |
6617 | * other threads running on this CPU then this function will return. | |
1da177e4 | 6618 | */ |
5add95d4 | 6619 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 6620 | { |
70b97a7f | 6621 | struct rq *rq = this_rq_lock(); |
1da177e4 | 6622 | |
2d72376b | 6623 | schedstat_inc(rq, yld_count); |
4530d7ab | 6624 | current->sched_class->yield_task(rq); |
1da177e4 LT |
6625 | |
6626 | /* | |
6627 | * Since we are going to call schedule() anyway, there's | |
6628 | * no need to preempt or enable interrupts: | |
6629 | */ | |
6630 | __release(rq->lock); | |
8a25d5de | 6631 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
1da177e4 LT |
6632 | _raw_spin_unlock(&rq->lock); |
6633 | preempt_enable_no_resched(); | |
6634 | ||
6635 | schedule(); | |
6636 | ||
6637 | return 0; | |
6638 | } | |
6639 | ||
d86ee480 PZ |
6640 | static inline int should_resched(void) |
6641 | { | |
6642 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
6643 | } | |
6644 | ||
e7b38404 | 6645 | static void __cond_resched(void) |
1da177e4 | 6646 | { |
e7aaaa69 FW |
6647 | add_preempt_count(PREEMPT_ACTIVE); |
6648 | schedule(); | |
6649 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
6650 | } |
6651 | ||
02b67cc3 | 6652 | int __sched _cond_resched(void) |
1da177e4 | 6653 | { |
d86ee480 | 6654 | if (should_resched()) { |
1da177e4 LT |
6655 | __cond_resched(); |
6656 | return 1; | |
6657 | } | |
6658 | return 0; | |
6659 | } | |
02b67cc3 | 6660 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
6661 | |
6662 | /* | |
613afbf8 | 6663 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
6664 | * call schedule, and on return reacquire the lock. |
6665 | * | |
41a2d6cf | 6666 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
6667 | * operations here to prevent schedule() from being called twice (once via |
6668 | * spin_unlock(), once by hand). | |
6669 | */ | |
613afbf8 | 6670 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 6671 | { |
d86ee480 | 6672 | int resched = should_resched(); |
6df3cecb JK |
6673 | int ret = 0; |
6674 | ||
f607c668 PZ |
6675 | lockdep_assert_held(lock); |
6676 | ||
95c354fe | 6677 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 6678 | spin_unlock(lock); |
d86ee480 | 6679 | if (resched) |
95c354fe NP |
6680 | __cond_resched(); |
6681 | else | |
6682 | cpu_relax(); | |
6df3cecb | 6683 | ret = 1; |
1da177e4 | 6684 | spin_lock(lock); |
1da177e4 | 6685 | } |
6df3cecb | 6686 | return ret; |
1da177e4 | 6687 | } |
613afbf8 | 6688 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 6689 | |
613afbf8 | 6690 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
6691 | { |
6692 | BUG_ON(!in_softirq()); | |
6693 | ||
d86ee480 | 6694 | if (should_resched()) { |
98d82567 | 6695 | local_bh_enable(); |
1da177e4 LT |
6696 | __cond_resched(); |
6697 | local_bh_disable(); | |
6698 | return 1; | |
6699 | } | |
6700 | return 0; | |
6701 | } | |
613afbf8 | 6702 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 6703 | |
1da177e4 LT |
6704 | /** |
6705 | * yield - yield the current processor to other threads. | |
6706 | * | |
72fd4a35 | 6707 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
6708 | * thread runnable and calls sys_sched_yield(). |
6709 | */ | |
6710 | void __sched yield(void) | |
6711 | { | |
6712 | set_current_state(TASK_RUNNING); | |
6713 | sys_sched_yield(); | |
6714 | } | |
1da177e4 LT |
6715 | EXPORT_SYMBOL(yield); |
6716 | ||
6717 | /* | |
41a2d6cf | 6718 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 LT |
6719 | * that process accounting knows that this is a task in IO wait state. |
6720 | * | |
6721 | * But don't do that if it is a deliberate, throttling IO wait (this task | |
6722 | * has set its backing_dev_info: the queue against which it should throttle) | |
6723 | */ | |
6724 | void __sched io_schedule(void) | |
6725 | { | |
54d35f29 | 6726 | struct rq *rq = raw_rq(); |
1da177e4 | 6727 | |
0ff92245 | 6728 | delayacct_blkio_start(); |
1da177e4 | 6729 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 6730 | current->in_iowait = 1; |
1da177e4 | 6731 | schedule(); |
8f0dfc34 | 6732 | current->in_iowait = 0; |
1da177e4 | 6733 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 6734 | delayacct_blkio_end(); |
1da177e4 | 6735 | } |
1da177e4 LT |
6736 | EXPORT_SYMBOL(io_schedule); |
6737 | ||
6738 | long __sched io_schedule_timeout(long timeout) | |
6739 | { | |
54d35f29 | 6740 | struct rq *rq = raw_rq(); |
1da177e4 LT |
6741 | long ret; |
6742 | ||
0ff92245 | 6743 | delayacct_blkio_start(); |
1da177e4 | 6744 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 6745 | current->in_iowait = 1; |
1da177e4 | 6746 | ret = schedule_timeout(timeout); |
8f0dfc34 | 6747 | current->in_iowait = 0; |
1da177e4 | 6748 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 6749 | delayacct_blkio_end(); |
1da177e4 LT |
6750 | return ret; |
6751 | } | |
6752 | ||
6753 | /** | |
6754 | * sys_sched_get_priority_max - return maximum RT priority. | |
6755 | * @policy: scheduling class. | |
6756 | * | |
6757 | * this syscall returns the maximum rt_priority that can be used | |
6758 | * by a given scheduling class. | |
6759 | */ | |
5add95d4 | 6760 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
6761 | { |
6762 | int ret = -EINVAL; | |
6763 | ||
6764 | switch (policy) { | |
6765 | case SCHED_FIFO: | |
6766 | case SCHED_RR: | |
6767 | ret = MAX_USER_RT_PRIO-1; | |
6768 | break; | |
6769 | case SCHED_NORMAL: | |
b0a9499c | 6770 | case SCHED_BATCH: |
dd41f596 | 6771 | case SCHED_IDLE: |
1da177e4 LT |
6772 | ret = 0; |
6773 | break; | |
6774 | } | |
6775 | return ret; | |
6776 | } | |
6777 | ||
6778 | /** | |
6779 | * sys_sched_get_priority_min - return minimum RT priority. | |
6780 | * @policy: scheduling class. | |
6781 | * | |
6782 | * this syscall returns the minimum rt_priority that can be used | |
6783 | * by a given scheduling class. | |
6784 | */ | |
5add95d4 | 6785 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
6786 | { |
6787 | int ret = -EINVAL; | |
6788 | ||
6789 | switch (policy) { | |
6790 | case SCHED_FIFO: | |
6791 | case SCHED_RR: | |
6792 | ret = 1; | |
6793 | break; | |
6794 | case SCHED_NORMAL: | |
b0a9499c | 6795 | case SCHED_BATCH: |
dd41f596 | 6796 | case SCHED_IDLE: |
1da177e4 LT |
6797 | ret = 0; |
6798 | } | |
6799 | return ret; | |
6800 | } | |
6801 | ||
6802 | /** | |
6803 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
6804 | * @pid: pid of the process. | |
6805 | * @interval: userspace pointer to the timeslice value. | |
6806 | * | |
6807 | * this syscall writes the default timeslice value of a given process | |
6808 | * into the user-space timespec buffer. A value of '0' means infinity. | |
6809 | */ | |
17da2bd9 | 6810 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 6811 | struct timespec __user *, interval) |
1da177e4 | 6812 | { |
36c8b586 | 6813 | struct task_struct *p; |
a4ec24b4 | 6814 | unsigned int time_slice; |
3a5c359a | 6815 | int retval; |
1da177e4 | 6816 | struct timespec t; |
1da177e4 LT |
6817 | |
6818 | if (pid < 0) | |
3a5c359a | 6819 | return -EINVAL; |
1da177e4 LT |
6820 | |
6821 | retval = -ESRCH; | |
6822 | read_lock(&tasklist_lock); | |
6823 | p = find_process_by_pid(pid); | |
6824 | if (!p) | |
6825 | goto out_unlock; | |
6826 | ||
6827 | retval = security_task_getscheduler(p); | |
6828 | if (retval) | |
6829 | goto out_unlock; | |
6830 | ||
77034937 IM |
6831 | /* |
6832 | * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER | |
6833 | * tasks that are on an otherwise idle runqueue: | |
6834 | */ | |
6835 | time_slice = 0; | |
6836 | if (p->policy == SCHED_RR) { | |
a4ec24b4 | 6837 | time_slice = DEF_TIMESLICE; |
1868f958 | 6838 | } else if (p->policy != SCHED_FIFO) { |
a4ec24b4 DA |
6839 | struct sched_entity *se = &p->se; |
6840 | unsigned long flags; | |
6841 | struct rq *rq; | |
6842 | ||
6843 | rq = task_rq_lock(p, &flags); | |
77034937 IM |
6844 | if (rq->cfs.load.weight) |
6845 | time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); | |
a4ec24b4 DA |
6846 | task_rq_unlock(rq, &flags); |
6847 | } | |
1da177e4 | 6848 | read_unlock(&tasklist_lock); |
a4ec24b4 | 6849 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 6850 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 6851 | return retval; |
3a5c359a | 6852 | |
1da177e4 LT |
6853 | out_unlock: |
6854 | read_unlock(&tasklist_lock); | |
6855 | return retval; | |
6856 | } | |
6857 | ||
7c731e0a | 6858 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 6859 | |
82a1fcb9 | 6860 | void sched_show_task(struct task_struct *p) |
1da177e4 | 6861 | { |
1da177e4 | 6862 | unsigned long free = 0; |
36c8b586 | 6863 | unsigned state; |
1da177e4 | 6864 | |
1da177e4 | 6865 | state = p->state ? __ffs(p->state) + 1 : 0; |
cc4ea795 | 6866 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 6867 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 6868 | #if BITS_PER_LONG == 32 |
1da177e4 | 6869 | if (state == TASK_RUNNING) |
cc4ea795 | 6870 | printk(KERN_CONT " running "); |
1da177e4 | 6871 | else |
cc4ea795 | 6872 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
6873 | #else |
6874 | if (state == TASK_RUNNING) | |
cc4ea795 | 6875 | printk(KERN_CONT " running task "); |
1da177e4 | 6876 | else |
cc4ea795 | 6877 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6878 | #endif |
6879 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 6880 | free = stack_not_used(p); |
1da177e4 | 6881 | #endif |
aa47b7e0 DR |
6882 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
6883 | task_pid_nr(p), task_pid_nr(p->real_parent), | |
6884 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 6885 | |
5fb5e6de | 6886 | show_stack(p, NULL); |
1da177e4 LT |
6887 | } |
6888 | ||
e59e2ae2 | 6889 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6890 | { |
36c8b586 | 6891 | struct task_struct *g, *p; |
1da177e4 | 6892 | |
4bd77321 IM |
6893 | #if BITS_PER_LONG == 32 |
6894 | printk(KERN_INFO | |
6895 | " task PC stack pid father\n"); | |
1da177e4 | 6896 | #else |
4bd77321 IM |
6897 | printk(KERN_INFO |
6898 | " task PC stack pid father\n"); | |
1da177e4 LT |
6899 | #endif |
6900 | read_lock(&tasklist_lock); | |
6901 | do_each_thread(g, p) { | |
6902 | /* | |
6903 | * reset the NMI-timeout, listing all files on a slow | |
6904 | * console might take alot of time: | |
6905 | */ | |
6906 | touch_nmi_watchdog(); | |
39bc89fd | 6907 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 6908 | sched_show_task(p); |
1da177e4 LT |
6909 | } while_each_thread(g, p); |
6910 | ||
04c9167f JF |
6911 | touch_all_softlockup_watchdogs(); |
6912 | ||
dd41f596 IM |
6913 | #ifdef CONFIG_SCHED_DEBUG |
6914 | sysrq_sched_debug_show(); | |
6915 | #endif | |
1da177e4 | 6916 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
6917 | /* |
6918 | * Only show locks if all tasks are dumped: | |
6919 | */ | |
6920 | if (state_filter == -1) | |
6921 | debug_show_all_locks(); | |
1da177e4 LT |
6922 | } |
6923 | ||
1df21055 IM |
6924 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
6925 | { | |
dd41f596 | 6926 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
6927 | } |
6928 | ||
f340c0d1 IM |
6929 | /** |
6930 | * init_idle - set up an idle thread for a given CPU | |
6931 | * @idle: task in question | |
6932 | * @cpu: cpu the idle task belongs to | |
6933 | * | |
6934 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
6935 | * flag, to make booting more robust. | |
6936 | */ | |
5c1e1767 | 6937 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 6938 | { |
70b97a7f | 6939 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
6940 | unsigned long flags; |
6941 | ||
5cbd54ef IM |
6942 | spin_lock_irqsave(&rq->lock, flags); |
6943 | ||
dd41f596 IM |
6944 | __sched_fork(idle); |
6945 | idle->se.exec_start = sched_clock(); | |
6946 | ||
b29739f9 | 6947 | idle->prio = idle->normal_prio = MAX_PRIO; |
96f874e2 | 6948 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 6949 | __set_task_cpu(idle, cpu); |
1da177e4 | 6950 | |
1da177e4 | 6951 | rq->curr = rq->idle = idle; |
4866cde0 NP |
6952 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
6953 | idle->oncpu = 1; | |
6954 | #endif | |
1da177e4 LT |
6955 | spin_unlock_irqrestore(&rq->lock, flags); |
6956 | ||
6957 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
6958 | #if defined(CONFIG_PREEMPT) |
6959 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
6960 | #else | |
a1261f54 | 6961 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 6962 | #endif |
dd41f596 IM |
6963 | /* |
6964 | * The idle tasks have their own, simple scheduling class: | |
6965 | */ | |
6966 | idle->sched_class = &idle_sched_class; | |
fb52607a | 6967 | ftrace_graph_init_task(idle); |
1da177e4 LT |
6968 | } |
6969 | ||
6970 | /* | |
6971 | * In a system that switches off the HZ timer nohz_cpu_mask | |
6972 | * indicates which cpus entered this state. This is used | |
6973 | * in the rcu update to wait only for active cpus. For system | |
6974 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 6975 | * always be CPU_BITS_NONE. |
1da177e4 | 6976 | */ |
6a7b3dc3 | 6977 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 6978 | |
19978ca6 IM |
6979 | /* |
6980 | * Increase the granularity value when there are more CPUs, | |
6981 | * because with more CPUs the 'effective latency' as visible | |
6982 | * to users decreases. But the relationship is not linear, | |
6983 | * so pick a second-best guess by going with the log2 of the | |
6984 | * number of CPUs. | |
6985 | * | |
6986 | * This idea comes from the SD scheduler of Con Kolivas: | |
6987 | */ | |
6988 | static inline void sched_init_granularity(void) | |
6989 | { | |
6990 | unsigned int factor = 1 + ilog2(num_online_cpus()); | |
6991 | const unsigned long limit = 200000000; | |
6992 | ||
6993 | sysctl_sched_min_granularity *= factor; | |
6994 | if (sysctl_sched_min_granularity > limit) | |
6995 | sysctl_sched_min_granularity = limit; | |
6996 | ||
6997 | sysctl_sched_latency *= factor; | |
6998 | if (sysctl_sched_latency > limit) | |
6999 | sysctl_sched_latency = limit; | |
7000 | ||
7001 | sysctl_sched_wakeup_granularity *= factor; | |
55cd5340 PZ |
7002 | |
7003 | sysctl_sched_shares_ratelimit *= factor; | |
19978ca6 IM |
7004 | } |
7005 | ||
1da177e4 LT |
7006 | #ifdef CONFIG_SMP |
7007 | /* | |
7008 | * This is how migration works: | |
7009 | * | |
70b97a7f | 7010 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
7011 | * runqueue and wake up that CPU's migration thread. |
7012 | * 2) we down() the locked semaphore => thread blocks. | |
7013 | * 3) migration thread wakes up (implicitly it forces the migrated | |
7014 | * thread off the CPU) | |
7015 | * 4) it gets the migration request and checks whether the migrated | |
7016 | * task is still in the wrong runqueue. | |
7017 | * 5) if it's in the wrong runqueue then the migration thread removes | |
7018 | * it and puts it into the right queue. | |
7019 | * 6) migration thread up()s the semaphore. | |
7020 | * 7) we wake up and the migration is done. | |
7021 | */ | |
7022 | ||
7023 | /* | |
7024 | * Change a given task's CPU affinity. Migrate the thread to a | |
7025 | * proper CPU and schedule it away if the CPU it's executing on | |
7026 | * is removed from the allowed bitmask. | |
7027 | * | |
7028 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 7029 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
7030 | * call is not atomic; no spinlocks may be held. |
7031 | */ | |
96f874e2 | 7032 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 7033 | { |
70b97a7f | 7034 | struct migration_req req; |
1da177e4 | 7035 | unsigned long flags; |
70b97a7f | 7036 | struct rq *rq; |
48f24c4d | 7037 | int ret = 0; |
1da177e4 LT |
7038 | |
7039 | rq = task_rq_lock(p, &flags); | |
96f874e2 | 7040 | if (!cpumask_intersects(new_mask, cpu_online_mask)) { |
1da177e4 LT |
7041 | ret = -EINVAL; |
7042 | goto out; | |
7043 | } | |
7044 | ||
9985b0ba | 7045 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 7046 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
7047 | ret = -EINVAL; |
7048 | goto out; | |
7049 | } | |
7050 | ||
73fe6aae | 7051 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 7052 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 7053 | else { |
96f874e2 RR |
7054 | cpumask_copy(&p->cpus_allowed, new_mask); |
7055 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
7056 | } |
7057 | ||
1da177e4 | 7058 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 7059 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
7060 | goto out; |
7061 | ||
1e5ce4f4 | 7062 | if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) { |
1da177e4 | 7063 | /* Need help from migration thread: drop lock and wait. */ |
693525e3 PZ |
7064 | struct task_struct *mt = rq->migration_thread; |
7065 | ||
7066 | get_task_struct(mt); | |
1da177e4 LT |
7067 | task_rq_unlock(rq, &flags); |
7068 | wake_up_process(rq->migration_thread); | |
693525e3 | 7069 | put_task_struct(mt); |
1da177e4 LT |
7070 | wait_for_completion(&req.done); |
7071 | tlb_migrate_finish(p->mm); | |
7072 | return 0; | |
7073 | } | |
7074 | out: | |
7075 | task_rq_unlock(rq, &flags); | |
48f24c4d | 7076 | |
1da177e4 LT |
7077 | return ret; |
7078 | } | |
cd8ba7cd | 7079 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
7080 | |
7081 | /* | |
41a2d6cf | 7082 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
7083 | * this because either it can't run here any more (set_cpus_allowed() |
7084 | * away from this CPU, or CPU going down), or because we're | |
7085 | * attempting to rebalance this task on exec (sched_exec). | |
7086 | * | |
7087 | * So we race with normal scheduler movements, but that's OK, as long | |
7088 | * as the task is no longer on this CPU. | |
efc30814 KK |
7089 | * |
7090 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 7091 | */ |
efc30814 | 7092 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 7093 | { |
70b97a7f | 7094 | struct rq *rq_dest, *rq_src; |
dd41f596 | 7095 | int ret = 0, on_rq; |
1da177e4 | 7096 | |
e761b772 | 7097 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 7098 | return ret; |
1da177e4 LT |
7099 | |
7100 | rq_src = cpu_rq(src_cpu); | |
7101 | rq_dest = cpu_rq(dest_cpu); | |
7102 | ||
7103 | double_rq_lock(rq_src, rq_dest); | |
7104 | /* Already moved. */ | |
7105 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 7106 | goto done; |
1da177e4 | 7107 | /* Affinity changed (again). */ |
96f874e2 | 7108 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 7109 | goto fail; |
1da177e4 | 7110 | |
dd41f596 | 7111 | on_rq = p->se.on_rq; |
6e82a3be | 7112 | if (on_rq) |
2e1cb74a | 7113 | deactivate_task(rq_src, p, 0); |
6e82a3be | 7114 | |
1da177e4 | 7115 | set_task_cpu(p, dest_cpu); |
dd41f596 IM |
7116 | if (on_rq) { |
7117 | activate_task(rq_dest, p, 0); | |
15afe09b | 7118 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 7119 | } |
b1e38734 | 7120 | done: |
efc30814 | 7121 | ret = 1; |
b1e38734 | 7122 | fail: |
1da177e4 | 7123 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 7124 | return ret; |
1da177e4 LT |
7125 | } |
7126 | ||
03b042bf PM |
7127 | #define RCU_MIGRATION_IDLE 0 |
7128 | #define RCU_MIGRATION_NEED_QS 1 | |
7129 | #define RCU_MIGRATION_GOT_QS 2 | |
7130 | #define RCU_MIGRATION_MUST_SYNC 3 | |
7131 | ||
1da177e4 LT |
7132 | /* |
7133 | * migration_thread - this is a highprio system thread that performs | |
7134 | * thread migration by bumping thread off CPU then 'pushing' onto | |
7135 | * another runqueue. | |
7136 | */ | |
95cdf3b7 | 7137 | static int migration_thread(void *data) |
1da177e4 | 7138 | { |
03b042bf | 7139 | int badcpu; |
1da177e4 | 7140 | int cpu = (long)data; |
70b97a7f | 7141 | struct rq *rq; |
1da177e4 LT |
7142 | |
7143 | rq = cpu_rq(cpu); | |
7144 | BUG_ON(rq->migration_thread != current); | |
7145 | ||
7146 | set_current_state(TASK_INTERRUPTIBLE); | |
7147 | while (!kthread_should_stop()) { | |
70b97a7f | 7148 | struct migration_req *req; |
1da177e4 | 7149 | struct list_head *head; |
1da177e4 | 7150 | |
1da177e4 LT |
7151 | spin_lock_irq(&rq->lock); |
7152 | ||
7153 | if (cpu_is_offline(cpu)) { | |
7154 | spin_unlock_irq(&rq->lock); | |
371cbb38 | 7155 | break; |
1da177e4 LT |
7156 | } |
7157 | ||
7158 | if (rq->active_balance) { | |
7159 | active_load_balance(rq, cpu); | |
7160 | rq->active_balance = 0; | |
7161 | } | |
7162 | ||
7163 | head = &rq->migration_queue; | |
7164 | ||
7165 | if (list_empty(head)) { | |
7166 | spin_unlock_irq(&rq->lock); | |
7167 | schedule(); | |
7168 | set_current_state(TASK_INTERRUPTIBLE); | |
7169 | continue; | |
7170 | } | |
70b97a7f | 7171 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
7172 | list_del_init(head->next); |
7173 | ||
03b042bf PM |
7174 | if (req->task != NULL) { |
7175 | spin_unlock(&rq->lock); | |
7176 | __migrate_task(req->task, cpu, req->dest_cpu); | |
7177 | } else if (likely(cpu == (badcpu = smp_processor_id()))) { | |
7178 | req->dest_cpu = RCU_MIGRATION_GOT_QS; | |
7179 | spin_unlock(&rq->lock); | |
7180 | } else { | |
7181 | req->dest_cpu = RCU_MIGRATION_MUST_SYNC; | |
7182 | spin_unlock(&rq->lock); | |
7183 | WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu); | |
7184 | } | |
674311d5 | 7185 | local_irq_enable(); |
1da177e4 LT |
7186 | |
7187 | complete(&req->done); | |
7188 | } | |
7189 | __set_current_state(TASK_RUNNING); | |
1da177e4 | 7190 | |
1da177e4 LT |
7191 | return 0; |
7192 | } | |
7193 | ||
7194 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
7195 | |
7196 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
7197 | { | |
7198 | int ret; | |
7199 | ||
7200 | local_irq_disable(); | |
7201 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
7202 | local_irq_enable(); | |
7203 | return ret; | |
7204 | } | |
7205 | ||
054b9108 | 7206 | /* |
3a4fa0a2 | 7207 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 7208 | */ |
48f24c4d | 7209 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 7210 | { |
70b97a7f | 7211 | int dest_cpu; |
6ca09dfc | 7212 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu)); |
e76bd8d9 RR |
7213 | |
7214 | again: | |
7215 | /* Look for allowed, online CPU in same node. */ | |
7216 | for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask) | |
7217 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
7218 | goto move; | |
7219 | ||
7220 | /* Any allowed, online CPU? */ | |
7221 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask); | |
7222 | if (dest_cpu < nr_cpu_ids) | |
7223 | goto move; | |
7224 | ||
7225 | /* No more Mr. Nice Guy. */ | |
7226 | if (dest_cpu >= nr_cpu_ids) { | |
e76bd8d9 RR |
7227 | cpuset_cpus_allowed_locked(p, &p->cpus_allowed); |
7228 | dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed); | |
1da177e4 | 7229 | |
e76bd8d9 RR |
7230 | /* |
7231 | * Don't tell them about moving exiting tasks or | |
7232 | * kernel threads (both mm NULL), since they never | |
7233 | * leave kernel. | |
7234 | */ | |
7235 | if (p->mm && printk_ratelimit()) { | |
7236 | printk(KERN_INFO "process %d (%s) no " | |
7237 | "longer affine to cpu%d\n", | |
7238 | task_pid_nr(p), p->comm, dead_cpu); | |
3a5c359a | 7239 | } |
e76bd8d9 RR |
7240 | } |
7241 | ||
7242 | move: | |
7243 | /* It can have affinity changed while we were choosing. */ | |
7244 | if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) | |
7245 | goto again; | |
1da177e4 LT |
7246 | } |
7247 | ||
7248 | /* | |
7249 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
7250 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
7251 | * for performance reasons the counter is not stricly tracking tasks to | |
7252 | * their home CPUs. So we just add the counter to another CPU's counter, | |
7253 | * to keep the global sum constant after CPU-down: | |
7254 | */ | |
70b97a7f | 7255 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 7256 | { |
1e5ce4f4 | 7257 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask)); |
1da177e4 LT |
7258 | unsigned long flags; |
7259 | ||
7260 | local_irq_save(flags); | |
7261 | double_rq_lock(rq_src, rq_dest); | |
7262 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
7263 | rq_src->nr_uninterruptible = 0; | |
7264 | double_rq_unlock(rq_src, rq_dest); | |
7265 | local_irq_restore(flags); | |
7266 | } | |
7267 | ||
7268 | /* Run through task list and migrate tasks from the dead cpu. */ | |
7269 | static void migrate_live_tasks(int src_cpu) | |
7270 | { | |
48f24c4d | 7271 | struct task_struct *p, *t; |
1da177e4 | 7272 | |
f7b4cddc | 7273 | read_lock(&tasklist_lock); |
1da177e4 | 7274 | |
48f24c4d IM |
7275 | do_each_thread(t, p) { |
7276 | if (p == current) | |
1da177e4 LT |
7277 | continue; |
7278 | ||
48f24c4d IM |
7279 | if (task_cpu(p) == src_cpu) |
7280 | move_task_off_dead_cpu(src_cpu, p); | |
7281 | } while_each_thread(t, p); | |
1da177e4 | 7282 | |
f7b4cddc | 7283 | read_unlock(&tasklist_lock); |
1da177e4 LT |
7284 | } |
7285 | ||
dd41f596 IM |
7286 | /* |
7287 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
7288 | * It does so by boosting its priority to highest possible. |
7289 | * Used by CPU offline code. | |
1da177e4 LT |
7290 | */ |
7291 | void sched_idle_next(void) | |
7292 | { | |
48f24c4d | 7293 | int this_cpu = smp_processor_id(); |
70b97a7f | 7294 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
7295 | struct task_struct *p = rq->idle; |
7296 | unsigned long flags; | |
7297 | ||
7298 | /* cpu has to be offline */ | |
48f24c4d | 7299 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 7300 | |
48f24c4d IM |
7301 | /* |
7302 | * Strictly not necessary since rest of the CPUs are stopped by now | |
7303 | * and interrupts disabled on the current cpu. | |
1da177e4 LT |
7304 | */ |
7305 | spin_lock_irqsave(&rq->lock, flags); | |
7306 | ||
dd41f596 | 7307 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 7308 | |
94bc9a7b DA |
7309 | update_rq_clock(rq); |
7310 | activate_task(rq, p, 0); | |
1da177e4 LT |
7311 | |
7312 | spin_unlock_irqrestore(&rq->lock, flags); | |
7313 | } | |
7314 | ||
48f24c4d IM |
7315 | /* |
7316 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
7317 | * offline. |
7318 | */ | |
7319 | void idle_task_exit(void) | |
7320 | { | |
7321 | struct mm_struct *mm = current->active_mm; | |
7322 | ||
7323 | BUG_ON(cpu_online(smp_processor_id())); | |
7324 | ||
7325 | if (mm != &init_mm) | |
7326 | switch_mm(mm, &init_mm, current); | |
7327 | mmdrop(mm); | |
7328 | } | |
7329 | ||
054b9108 | 7330 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 7331 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 7332 | { |
70b97a7f | 7333 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
7334 | |
7335 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 7336 | BUG_ON(!p->exit_state); |
1da177e4 LT |
7337 | |
7338 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 7339 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 7340 | |
48f24c4d | 7341 | get_task_struct(p); |
1da177e4 LT |
7342 | |
7343 | /* | |
7344 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 7345 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
7346 | * fine. |
7347 | */ | |
f7b4cddc | 7348 | spin_unlock_irq(&rq->lock); |
48f24c4d | 7349 | move_task_off_dead_cpu(dead_cpu, p); |
f7b4cddc | 7350 | spin_lock_irq(&rq->lock); |
1da177e4 | 7351 | |
48f24c4d | 7352 | put_task_struct(p); |
1da177e4 LT |
7353 | } |
7354 | ||
7355 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
7356 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
7357 | { | |
70b97a7f | 7358 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 7359 | struct task_struct *next; |
48f24c4d | 7360 | |
dd41f596 IM |
7361 | for ( ; ; ) { |
7362 | if (!rq->nr_running) | |
7363 | break; | |
a8e504d2 | 7364 | update_rq_clock(rq); |
b67802ea | 7365 | next = pick_next_task(rq); |
dd41f596 IM |
7366 | if (!next) |
7367 | break; | |
79c53799 | 7368 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 7369 | migrate_dead(dead_cpu, next); |
e692ab53 | 7370 | |
1da177e4 LT |
7371 | } |
7372 | } | |
dce48a84 TG |
7373 | |
7374 | /* | |
7375 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
7376 | */ | |
7377 | static void calc_global_load_remove(struct rq *rq) | |
7378 | { | |
7379 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 7380 | rq->calc_load_active = 0; |
dce48a84 | 7381 | } |
1da177e4 LT |
7382 | #endif /* CONFIG_HOTPLUG_CPU */ |
7383 | ||
e692ab53 NP |
7384 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
7385 | ||
7386 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
7387 | { |
7388 | .procname = "sched_domain", | |
c57baf1e | 7389 | .mode = 0555, |
e0361851 | 7390 | }, |
38605cae | 7391 | {0, }, |
e692ab53 NP |
7392 | }; |
7393 | ||
7394 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 | 7395 | { |
c57baf1e | 7396 | .ctl_name = CTL_KERN, |
e0361851 | 7397 | .procname = "kernel", |
c57baf1e | 7398 | .mode = 0555, |
e0361851 AD |
7399 | .child = sd_ctl_dir, |
7400 | }, | |
38605cae | 7401 | {0, }, |
e692ab53 NP |
7402 | }; |
7403 | ||
7404 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
7405 | { | |
7406 | struct ctl_table *entry = | |
5cf9f062 | 7407 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 7408 | |
e692ab53 NP |
7409 | return entry; |
7410 | } | |
7411 | ||
6382bc90 MM |
7412 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
7413 | { | |
cd790076 | 7414 | struct ctl_table *entry; |
6382bc90 | 7415 | |
cd790076 MM |
7416 | /* |
7417 | * In the intermediate directories, both the child directory and | |
7418 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 7419 | * will always be set. In the lowest directory the names are |
cd790076 MM |
7420 | * static strings and all have proc handlers. |
7421 | */ | |
7422 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
7423 | if (entry->child) |
7424 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
7425 | if (entry->proc_handler == NULL) |
7426 | kfree(entry->procname); | |
7427 | } | |
6382bc90 MM |
7428 | |
7429 | kfree(*tablep); | |
7430 | *tablep = NULL; | |
7431 | } | |
7432 | ||
e692ab53 | 7433 | static void |
e0361851 | 7434 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
7435 | const char *procname, void *data, int maxlen, |
7436 | mode_t mode, proc_handler *proc_handler) | |
7437 | { | |
e692ab53 NP |
7438 | entry->procname = procname; |
7439 | entry->data = data; | |
7440 | entry->maxlen = maxlen; | |
7441 | entry->mode = mode; | |
7442 | entry->proc_handler = proc_handler; | |
7443 | } | |
7444 | ||
7445 | static struct ctl_table * | |
7446 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
7447 | { | |
a5d8c348 | 7448 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 7449 | |
ad1cdc1d MM |
7450 | if (table == NULL) |
7451 | return NULL; | |
7452 | ||
e0361851 | 7453 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 7454 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 7455 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 7456 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 7457 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 7458 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7459 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 7460 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7461 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 7462 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7463 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 7464 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7465 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 7466 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7467 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 7468 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7469 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 7470 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 7471 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
7472 | &sd->cache_nice_tries, |
7473 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 7474 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 7475 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
7476 | set_table_entry(&table[11], "name", sd->name, |
7477 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
7478 | /* &table[12] is terminator */ | |
e692ab53 NP |
7479 | |
7480 | return table; | |
7481 | } | |
7482 | ||
9a4e7159 | 7483 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
7484 | { |
7485 | struct ctl_table *entry, *table; | |
7486 | struct sched_domain *sd; | |
7487 | int domain_num = 0, i; | |
7488 | char buf[32]; | |
7489 | ||
7490 | for_each_domain(cpu, sd) | |
7491 | domain_num++; | |
7492 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
7493 | if (table == NULL) |
7494 | return NULL; | |
e692ab53 NP |
7495 | |
7496 | i = 0; | |
7497 | for_each_domain(cpu, sd) { | |
7498 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 7499 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 7500 | entry->mode = 0555; |
e692ab53 NP |
7501 | entry->child = sd_alloc_ctl_domain_table(sd); |
7502 | entry++; | |
7503 | i++; | |
7504 | } | |
7505 | return table; | |
7506 | } | |
7507 | ||
7508 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 7509 | static void register_sched_domain_sysctl(void) |
e692ab53 NP |
7510 | { |
7511 | int i, cpu_num = num_online_cpus(); | |
7512 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); | |
7513 | char buf[32]; | |
7514 | ||
7378547f MM |
7515 | WARN_ON(sd_ctl_dir[0].child); |
7516 | sd_ctl_dir[0].child = entry; | |
7517 | ||
ad1cdc1d MM |
7518 | if (entry == NULL) |
7519 | return; | |
7520 | ||
97b6ea7b | 7521 | for_each_online_cpu(i) { |
e692ab53 | 7522 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 7523 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 7524 | entry->mode = 0555; |
e692ab53 | 7525 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 7526 | entry++; |
e692ab53 | 7527 | } |
7378547f MM |
7528 | |
7529 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
7530 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
7531 | } | |
6382bc90 | 7532 | |
7378547f | 7533 | /* may be called multiple times per register */ |
6382bc90 MM |
7534 | static void unregister_sched_domain_sysctl(void) |
7535 | { | |
7378547f MM |
7536 | if (sd_sysctl_header) |
7537 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 7538 | sd_sysctl_header = NULL; |
7378547f MM |
7539 | if (sd_ctl_dir[0].child) |
7540 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 7541 | } |
e692ab53 | 7542 | #else |
6382bc90 MM |
7543 | static void register_sched_domain_sysctl(void) |
7544 | { | |
7545 | } | |
7546 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
7547 | { |
7548 | } | |
7549 | #endif | |
7550 | ||
1f11eb6a GH |
7551 | static void set_rq_online(struct rq *rq) |
7552 | { | |
7553 | if (!rq->online) { | |
7554 | const struct sched_class *class; | |
7555 | ||
c6c4927b | 7556 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
7557 | rq->online = 1; |
7558 | ||
7559 | for_each_class(class) { | |
7560 | if (class->rq_online) | |
7561 | class->rq_online(rq); | |
7562 | } | |
7563 | } | |
7564 | } | |
7565 | ||
7566 | static void set_rq_offline(struct rq *rq) | |
7567 | { | |
7568 | if (rq->online) { | |
7569 | const struct sched_class *class; | |
7570 | ||
7571 | for_each_class(class) { | |
7572 | if (class->rq_offline) | |
7573 | class->rq_offline(rq); | |
7574 | } | |
7575 | ||
c6c4927b | 7576 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
7577 | rq->online = 0; |
7578 | } | |
7579 | } | |
7580 | ||
1da177e4 LT |
7581 | /* |
7582 | * migration_call - callback that gets triggered when a CPU is added. | |
7583 | * Here we can start up the necessary migration thread for the new CPU. | |
7584 | */ | |
48f24c4d IM |
7585 | static int __cpuinit |
7586 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 7587 | { |
1da177e4 | 7588 | struct task_struct *p; |
48f24c4d | 7589 | int cpu = (long)hcpu; |
1da177e4 | 7590 | unsigned long flags; |
70b97a7f | 7591 | struct rq *rq; |
1da177e4 LT |
7592 | |
7593 | switch (action) { | |
5be9361c | 7594 | |
1da177e4 | 7595 | case CPU_UP_PREPARE: |
8bb78442 | 7596 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 7597 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
7598 | if (IS_ERR(p)) |
7599 | return NOTIFY_BAD; | |
1da177e4 LT |
7600 | kthread_bind(p, cpu); |
7601 | /* Must be high prio: stop_machine expects to yield to it. */ | |
7602 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 7603 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 | 7604 | task_rq_unlock(rq, &flags); |
371cbb38 | 7605 | get_task_struct(p); |
1da177e4 | 7606 | cpu_rq(cpu)->migration_thread = p; |
a468d389 | 7607 | rq->calc_load_update = calc_load_update; |
1da177e4 | 7608 | break; |
48f24c4d | 7609 | |
1da177e4 | 7610 | case CPU_ONLINE: |
8bb78442 | 7611 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 7612 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 7613 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
7614 | |
7615 | /* Update our root-domain */ | |
7616 | rq = cpu_rq(cpu); | |
7617 | spin_lock_irqsave(&rq->lock, flags); | |
7618 | if (rq->rd) { | |
c6c4927b | 7619 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
7620 | |
7621 | set_rq_online(rq); | |
1f94ef59 GH |
7622 | } |
7623 | spin_unlock_irqrestore(&rq->lock, flags); | |
1da177e4 | 7624 | break; |
48f24c4d | 7625 | |
1da177e4 LT |
7626 | #ifdef CONFIG_HOTPLUG_CPU |
7627 | case CPU_UP_CANCELED: | |
8bb78442 | 7628 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
7629 | if (!cpu_rq(cpu)->migration_thread) |
7630 | break; | |
41a2d6cf | 7631 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 7632 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 7633 | cpumask_any(cpu_online_mask)); |
1da177e4 | 7634 | kthread_stop(cpu_rq(cpu)->migration_thread); |
371cbb38 | 7635 | put_task_struct(cpu_rq(cpu)->migration_thread); |
1da177e4 LT |
7636 | cpu_rq(cpu)->migration_thread = NULL; |
7637 | break; | |
48f24c4d | 7638 | |
1da177e4 | 7639 | case CPU_DEAD: |
8bb78442 | 7640 | case CPU_DEAD_FROZEN: |
470fd646 | 7641 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
7642 | migrate_live_tasks(cpu); |
7643 | rq = cpu_rq(cpu); | |
7644 | kthread_stop(rq->migration_thread); | |
371cbb38 | 7645 | put_task_struct(rq->migration_thread); |
1da177e4 LT |
7646 | rq->migration_thread = NULL; |
7647 | /* Idle task back to normal (off runqueue, low prio) */ | |
d2da272a | 7648 | spin_lock_irq(&rq->lock); |
a8e504d2 | 7649 | update_rq_clock(rq); |
2e1cb74a | 7650 | deactivate_task(rq, rq->idle, 0); |
1da177e4 | 7651 | rq->idle->static_prio = MAX_PRIO; |
dd41f596 IM |
7652 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
7653 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 7654 | migrate_dead_tasks(cpu); |
d2da272a | 7655 | spin_unlock_irq(&rq->lock); |
470fd646 | 7656 | cpuset_unlock(); |
1da177e4 LT |
7657 | migrate_nr_uninterruptible(rq); |
7658 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 7659 | calc_global_load_remove(rq); |
41a2d6cf IM |
7660 | /* |
7661 | * No need to migrate the tasks: it was best-effort if | |
7662 | * they didn't take sched_hotcpu_mutex. Just wake up | |
7663 | * the requestors. | |
7664 | */ | |
1da177e4 LT |
7665 | spin_lock_irq(&rq->lock); |
7666 | while (!list_empty(&rq->migration_queue)) { | |
70b97a7f IM |
7667 | struct migration_req *req; |
7668 | ||
1da177e4 | 7669 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 7670 | struct migration_req, list); |
1da177e4 | 7671 | list_del_init(&req->list); |
9a2bd244 | 7672 | spin_unlock_irq(&rq->lock); |
1da177e4 | 7673 | complete(&req->done); |
9a2bd244 | 7674 | spin_lock_irq(&rq->lock); |
1da177e4 LT |
7675 | } |
7676 | spin_unlock_irq(&rq->lock); | |
7677 | break; | |
57d885fe | 7678 | |
08f503b0 GH |
7679 | case CPU_DYING: |
7680 | case CPU_DYING_FROZEN: | |
57d885fe GH |
7681 | /* Update our root-domain */ |
7682 | rq = cpu_rq(cpu); | |
7683 | spin_lock_irqsave(&rq->lock, flags); | |
7684 | if (rq->rd) { | |
c6c4927b | 7685 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 7686 | set_rq_offline(rq); |
57d885fe GH |
7687 | } |
7688 | spin_unlock_irqrestore(&rq->lock, flags); | |
7689 | break; | |
1da177e4 LT |
7690 | #endif |
7691 | } | |
7692 | return NOTIFY_OK; | |
7693 | } | |
7694 | ||
f38b0820 PM |
7695 | /* |
7696 | * Register at high priority so that task migration (migrate_all_tasks) | |
7697 | * happens before everything else. This has to be lower priority than | |
7698 | * the notifier in the perf_counter subsystem, though. | |
1da177e4 | 7699 | */ |
26c2143b | 7700 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
7701 | .notifier_call = migration_call, |
7702 | .priority = 10 | |
7703 | }; | |
7704 | ||
7babe8db | 7705 | static int __init migration_init(void) |
1da177e4 LT |
7706 | { |
7707 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 7708 | int err; |
48f24c4d IM |
7709 | |
7710 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
7711 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
7712 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
7713 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
7714 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 7715 | |
a004cd42 | 7716 | return 0; |
1da177e4 | 7717 | } |
7babe8db | 7718 | early_initcall(migration_init); |
1da177e4 LT |
7719 | #endif |
7720 | ||
7721 | #ifdef CONFIG_SMP | |
476f3534 | 7722 | |
3e9830dc | 7723 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 7724 | |
7c16ec58 | 7725 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 7726 | struct cpumask *groupmask) |
1da177e4 | 7727 | { |
4dcf6aff | 7728 | struct sched_group *group = sd->groups; |
434d53b0 | 7729 | char str[256]; |
1da177e4 | 7730 | |
968ea6d8 | 7731 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 7732 | cpumask_clear(groupmask); |
4dcf6aff IM |
7733 | |
7734 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
7735 | ||
7736 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
7737 | printk("does not load-balance\n"); | |
7738 | if (sd->parent) | |
7739 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" | |
7740 | " has parent"); | |
7741 | return -1; | |
41c7ce9a NP |
7742 | } |
7743 | ||
eefd796a | 7744 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 7745 | |
758b2cdc | 7746 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
4dcf6aff IM |
7747 | printk(KERN_ERR "ERROR: domain->span does not contain " |
7748 | "CPU%d\n", cpu); | |
7749 | } | |
758b2cdc | 7750 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
4dcf6aff IM |
7751 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
7752 | " CPU%d\n", cpu); | |
7753 | } | |
1da177e4 | 7754 | |
4dcf6aff | 7755 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 7756 | do { |
4dcf6aff IM |
7757 | if (!group) { |
7758 | printk("\n"); | |
7759 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
7760 | break; |
7761 | } | |
7762 | ||
18a3885f | 7763 | if (!group->cpu_power) { |
4dcf6aff IM |
7764 | printk(KERN_CONT "\n"); |
7765 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
7766 | "set\n"); | |
7767 | break; | |
7768 | } | |
1da177e4 | 7769 | |
758b2cdc | 7770 | if (!cpumask_weight(sched_group_cpus(group))) { |
4dcf6aff IM |
7771 | printk(KERN_CONT "\n"); |
7772 | printk(KERN_ERR "ERROR: empty group\n"); | |
7773 | break; | |
7774 | } | |
1da177e4 | 7775 | |
758b2cdc | 7776 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
4dcf6aff IM |
7777 | printk(KERN_CONT "\n"); |
7778 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
7779 | break; | |
7780 | } | |
1da177e4 | 7781 | |
758b2cdc | 7782 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 7783 | |
968ea6d8 | 7784 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf GS |
7785 | |
7786 | printk(KERN_CONT " %s", str); | |
18a3885f PZ |
7787 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
7788 | printk(KERN_CONT " (cpu_power = %d)", | |
7789 | group->cpu_power); | |
381512cf | 7790 | } |
1da177e4 | 7791 | |
4dcf6aff IM |
7792 | group = group->next; |
7793 | } while (group != sd->groups); | |
7794 | printk(KERN_CONT "\n"); | |
1da177e4 | 7795 | |
758b2cdc | 7796 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
4dcf6aff | 7797 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 7798 | |
758b2cdc RR |
7799 | if (sd->parent && |
7800 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
4dcf6aff IM |
7801 | printk(KERN_ERR "ERROR: parent span is not a superset " |
7802 | "of domain->span\n"); | |
7803 | return 0; | |
7804 | } | |
1da177e4 | 7805 | |
4dcf6aff IM |
7806 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
7807 | { | |
d5dd3db1 | 7808 | cpumask_var_t groupmask; |
4dcf6aff | 7809 | int level = 0; |
1da177e4 | 7810 | |
4dcf6aff IM |
7811 | if (!sd) { |
7812 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
7813 | return; | |
7814 | } | |
1da177e4 | 7815 | |
4dcf6aff IM |
7816 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
7817 | ||
d5dd3db1 | 7818 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
7819 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
7820 | return; | |
7821 | } | |
7822 | ||
4dcf6aff | 7823 | for (;;) { |
7c16ec58 | 7824 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 7825 | break; |
1da177e4 LT |
7826 | level++; |
7827 | sd = sd->parent; | |
33859f7f | 7828 | if (!sd) |
4dcf6aff IM |
7829 | break; |
7830 | } | |
d5dd3db1 | 7831 | free_cpumask_var(groupmask); |
1da177e4 | 7832 | } |
6d6bc0ad | 7833 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 7834 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 7835 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 7836 | |
1a20ff27 | 7837 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 7838 | { |
758b2cdc | 7839 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
7840 | return 1; |
7841 | ||
7842 | /* Following flags need at least 2 groups */ | |
7843 | if (sd->flags & (SD_LOAD_BALANCE | | |
7844 | SD_BALANCE_NEWIDLE | | |
7845 | SD_BALANCE_FORK | | |
89c4710e SS |
7846 | SD_BALANCE_EXEC | |
7847 | SD_SHARE_CPUPOWER | | |
7848 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
7849 | if (sd->groups != sd->groups->next) |
7850 | return 0; | |
7851 | } | |
7852 | ||
7853 | /* Following flags don't use groups */ | |
7854 | if (sd->flags & (SD_WAKE_IDLE | | |
7855 | SD_WAKE_AFFINE | | |
7856 | SD_WAKE_BALANCE)) | |
7857 | return 0; | |
7858 | ||
7859 | return 1; | |
7860 | } | |
7861 | ||
48f24c4d IM |
7862 | static int |
7863 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
7864 | { |
7865 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
7866 | ||
7867 | if (sd_degenerate(parent)) | |
7868 | return 1; | |
7869 | ||
758b2cdc | 7870 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
7871 | return 0; |
7872 | ||
7873 | /* Does parent contain flags not in child? */ | |
7874 | /* WAKE_BALANCE is a subset of WAKE_AFFINE */ | |
7875 | if (cflags & SD_WAKE_AFFINE) | |
7876 | pflags &= ~SD_WAKE_BALANCE; | |
7877 | /* Flags needing groups don't count if only 1 group in parent */ | |
7878 | if (parent->groups == parent->groups->next) { | |
7879 | pflags &= ~(SD_LOAD_BALANCE | | |
7880 | SD_BALANCE_NEWIDLE | | |
7881 | SD_BALANCE_FORK | | |
89c4710e SS |
7882 | SD_BALANCE_EXEC | |
7883 | SD_SHARE_CPUPOWER | | |
7884 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
7885 | if (nr_node_ids == 1) |
7886 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
7887 | } |
7888 | if (~cflags & pflags) | |
7889 | return 0; | |
7890 | ||
7891 | return 1; | |
7892 | } | |
7893 | ||
c6c4927b RR |
7894 | static void free_rootdomain(struct root_domain *rd) |
7895 | { | |
68e74568 RR |
7896 | cpupri_cleanup(&rd->cpupri); |
7897 | ||
c6c4927b RR |
7898 | free_cpumask_var(rd->rto_mask); |
7899 | free_cpumask_var(rd->online); | |
7900 | free_cpumask_var(rd->span); | |
7901 | kfree(rd); | |
7902 | } | |
7903 | ||
57d885fe GH |
7904 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
7905 | { | |
a0490fa3 | 7906 | struct root_domain *old_rd = NULL; |
57d885fe | 7907 | unsigned long flags; |
57d885fe GH |
7908 | |
7909 | spin_lock_irqsave(&rq->lock, flags); | |
7910 | ||
7911 | if (rq->rd) { | |
a0490fa3 | 7912 | old_rd = rq->rd; |
57d885fe | 7913 | |
c6c4927b | 7914 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 7915 | set_rq_offline(rq); |
57d885fe | 7916 | |
c6c4927b | 7917 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 7918 | |
a0490fa3 IM |
7919 | /* |
7920 | * If we dont want to free the old_rt yet then | |
7921 | * set old_rd to NULL to skip the freeing later | |
7922 | * in this function: | |
7923 | */ | |
7924 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
7925 | old_rd = NULL; | |
57d885fe GH |
7926 | } |
7927 | ||
7928 | atomic_inc(&rd->refcount); | |
7929 | rq->rd = rd; | |
7930 | ||
c6c4927b | 7931 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 7932 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 7933 | set_rq_online(rq); |
57d885fe GH |
7934 | |
7935 | spin_unlock_irqrestore(&rq->lock, flags); | |
a0490fa3 IM |
7936 | |
7937 | if (old_rd) | |
7938 | free_rootdomain(old_rd); | |
57d885fe GH |
7939 | } |
7940 | ||
fd5e1b5d | 7941 | static int init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe | 7942 | { |
36b7b6d4 PE |
7943 | gfp_t gfp = GFP_KERNEL; |
7944 | ||
57d885fe GH |
7945 | memset(rd, 0, sizeof(*rd)); |
7946 | ||
36b7b6d4 PE |
7947 | if (bootmem) |
7948 | gfp = GFP_NOWAIT; | |
c6c4927b | 7949 | |
36b7b6d4 | 7950 | if (!alloc_cpumask_var(&rd->span, gfp)) |
0c910d28 | 7951 | goto out; |
36b7b6d4 | 7952 | if (!alloc_cpumask_var(&rd->online, gfp)) |
c6c4927b | 7953 | goto free_span; |
36b7b6d4 | 7954 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) |
c6c4927b | 7955 | goto free_online; |
6e0534f2 | 7956 | |
0fb53029 | 7957 | if (cpupri_init(&rd->cpupri, bootmem) != 0) |
68e74568 | 7958 | goto free_rto_mask; |
c6c4927b | 7959 | return 0; |
6e0534f2 | 7960 | |
68e74568 RR |
7961 | free_rto_mask: |
7962 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
7963 | free_online: |
7964 | free_cpumask_var(rd->online); | |
7965 | free_span: | |
7966 | free_cpumask_var(rd->span); | |
0c910d28 | 7967 | out: |
c6c4927b | 7968 | return -ENOMEM; |
57d885fe GH |
7969 | } |
7970 | ||
7971 | static void init_defrootdomain(void) | |
7972 | { | |
c6c4927b RR |
7973 | init_rootdomain(&def_root_domain, true); |
7974 | ||
57d885fe GH |
7975 | atomic_set(&def_root_domain.refcount, 1); |
7976 | } | |
7977 | ||
dc938520 | 7978 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
7979 | { |
7980 | struct root_domain *rd; | |
7981 | ||
7982 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
7983 | if (!rd) | |
7984 | return NULL; | |
7985 | ||
c6c4927b RR |
7986 | if (init_rootdomain(rd, false) != 0) { |
7987 | kfree(rd); | |
7988 | return NULL; | |
7989 | } | |
57d885fe GH |
7990 | |
7991 | return rd; | |
7992 | } | |
7993 | ||
1da177e4 | 7994 | /* |
0eab9146 | 7995 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
7996 | * hold the hotplug lock. |
7997 | */ | |
0eab9146 IM |
7998 | static void |
7999 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 8000 | { |
70b97a7f | 8001 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
8002 | struct sched_domain *tmp; |
8003 | ||
8004 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 8005 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
8006 | struct sched_domain *parent = tmp->parent; |
8007 | if (!parent) | |
8008 | break; | |
f29c9b1c | 8009 | |
1a848870 | 8010 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 8011 | tmp->parent = parent->parent; |
1a848870 SS |
8012 | if (parent->parent) |
8013 | parent->parent->child = tmp; | |
f29c9b1c LZ |
8014 | } else |
8015 | tmp = tmp->parent; | |
245af2c7 SS |
8016 | } |
8017 | ||
1a848870 | 8018 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 8019 | sd = sd->parent; |
1a848870 SS |
8020 | if (sd) |
8021 | sd->child = NULL; | |
8022 | } | |
1da177e4 LT |
8023 | |
8024 | sched_domain_debug(sd, cpu); | |
8025 | ||
57d885fe | 8026 | rq_attach_root(rq, rd); |
674311d5 | 8027 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
8028 | } |
8029 | ||
8030 | /* cpus with isolated domains */ | |
dcc30a35 | 8031 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
8032 | |
8033 | /* Setup the mask of cpus configured for isolated domains */ | |
8034 | static int __init isolated_cpu_setup(char *str) | |
8035 | { | |
968ea6d8 | 8036 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
8037 | return 1; |
8038 | } | |
8039 | ||
8927f494 | 8040 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
8041 | |
8042 | /* | |
6711cab4 SS |
8043 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
8044 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
8045 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
8046 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
8047 | * |
8048 | * init_sched_build_groups will build a circular linked list of the groups | |
8049 | * covered by the given span, and will set each group's ->cpumask correctly, | |
8050 | * and ->cpu_power to 0. | |
8051 | */ | |
a616058b | 8052 | static void |
96f874e2 RR |
8053 | init_sched_build_groups(const struct cpumask *span, |
8054 | const struct cpumask *cpu_map, | |
8055 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 8056 | struct sched_group **sg, |
96f874e2 RR |
8057 | struct cpumask *tmpmask), |
8058 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
8059 | { |
8060 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
8061 | int i; |
8062 | ||
96f874e2 | 8063 | cpumask_clear(covered); |
7c16ec58 | 8064 | |
abcd083a | 8065 | for_each_cpu(i, span) { |
6711cab4 | 8066 | struct sched_group *sg; |
7c16ec58 | 8067 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
8068 | int j; |
8069 | ||
758b2cdc | 8070 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
8071 | continue; |
8072 | ||
758b2cdc | 8073 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 8074 | sg->cpu_power = 0; |
1da177e4 | 8075 | |
abcd083a | 8076 | for_each_cpu(j, span) { |
7c16ec58 | 8077 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
8078 | continue; |
8079 | ||
96f874e2 | 8080 | cpumask_set_cpu(j, covered); |
758b2cdc | 8081 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
8082 | } |
8083 | if (!first) | |
8084 | first = sg; | |
8085 | if (last) | |
8086 | last->next = sg; | |
8087 | last = sg; | |
8088 | } | |
8089 | last->next = first; | |
8090 | } | |
8091 | ||
9c1cfda2 | 8092 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 8093 | |
9c1cfda2 | 8094 | #ifdef CONFIG_NUMA |
198e2f18 | 8095 | |
9c1cfda2 JH |
8096 | /** |
8097 | * find_next_best_node - find the next node to include in a sched_domain | |
8098 | * @node: node whose sched_domain we're building | |
8099 | * @used_nodes: nodes already in the sched_domain | |
8100 | * | |
41a2d6cf | 8101 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
8102 | * finds the closest node not already in the @used_nodes map. |
8103 | * | |
8104 | * Should use nodemask_t. | |
8105 | */ | |
c5f59f08 | 8106 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
8107 | { |
8108 | int i, n, val, min_val, best_node = 0; | |
8109 | ||
8110 | min_val = INT_MAX; | |
8111 | ||
076ac2af | 8112 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 8113 | /* Start at @node */ |
076ac2af | 8114 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
8115 | |
8116 | if (!nr_cpus_node(n)) | |
8117 | continue; | |
8118 | ||
8119 | /* Skip already used nodes */ | |
c5f59f08 | 8120 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
8121 | continue; |
8122 | ||
8123 | /* Simple min distance search */ | |
8124 | val = node_distance(node, n); | |
8125 | ||
8126 | if (val < min_val) { | |
8127 | min_val = val; | |
8128 | best_node = n; | |
8129 | } | |
8130 | } | |
8131 | ||
c5f59f08 | 8132 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
8133 | return best_node; |
8134 | } | |
8135 | ||
8136 | /** | |
8137 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
8138 | * @node: node whose cpumask we're constructing | |
73486722 | 8139 | * @span: resulting cpumask |
9c1cfda2 | 8140 | * |
41a2d6cf | 8141 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
8142 | * should be one that prevents unnecessary balancing, but also spreads tasks |
8143 | * out optimally. | |
8144 | */ | |
96f874e2 | 8145 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 8146 | { |
c5f59f08 | 8147 | nodemask_t used_nodes; |
48f24c4d | 8148 | int i; |
9c1cfda2 | 8149 | |
6ca09dfc | 8150 | cpumask_clear(span); |
c5f59f08 | 8151 | nodes_clear(used_nodes); |
9c1cfda2 | 8152 | |
6ca09dfc | 8153 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 8154 | node_set(node, used_nodes); |
9c1cfda2 JH |
8155 | |
8156 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 8157 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 8158 | |
6ca09dfc | 8159 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 8160 | } |
9c1cfda2 | 8161 | } |
6d6bc0ad | 8162 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 8163 | |
5c45bf27 | 8164 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 8165 | |
6c99e9ad RR |
8166 | /* |
8167 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
8168 | * |
8169 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
8170 | * and struct sched_domain. ) | |
6c99e9ad RR |
8171 | */ |
8172 | struct static_sched_group { | |
8173 | struct sched_group sg; | |
8174 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
8175 | }; | |
8176 | ||
8177 | struct static_sched_domain { | |
8178 | struct sched_domain sd; | |
8179 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
8180 | }; | |
8181 | ||
49a02c51 AH |
8182 | struct s_data { |
8183 | #ifdef CONFIG_NUMA | |
8184 | int sd_allnodes; | |
8185 | cpumask_var_t domainspan; | |
8186 | cpumask_var_t covered; | |
8187 | cpumask_var_t notcovered; | |
8188 | #endif | |
8189 | cpumask_var_t nodemask; | |
8190 | cpumask_var_t this_sibling_map; | |
8191 | cpumask_var_t this_core_map; | |
8192 | cpumask_var_t send_covered; | |
8193 | cpumask_var_t tmpmask; | |
8194 | struct sched_group **sched_group_nodes; | |
8195 | struct root_domain *rd; | |
8196 | }; | |
8197 | ||
2109b99e AH |
8198 | enum s_alloc { |
8199 | sa_sched_groups = 0, | |
8200 | sa_rootdomain, | |
8201 | sa_tmpmask, | |
8202 | sa_send_covered, | |
8203 | sa_this_core_map, | |
8204 | sa_this_sibling_map, | |
8205 | sa_nodemask, | |
8206 | sa_sched_group_nodes, | |
8207 | #ifdef CONFIG_NUMA | |
8208 | sa_notcovered, | |
8209 | sa_covered, | |
8210 | sa_domainspan, | |
8211 | #endif | |
8212 | sa_none, | |
8213 | }; | |
8214 | ||
9c1cfda2 | 8215 | /* |
48f24c4d | 8216 | * SMT sched-domains: |
9c1cfda2 | 8217 | */ |
1da177e4 | 8218 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad RR |
8219 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
8220 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus); | |
48f24c4d | 8221 | |
41a2d6cf | 8222 | static int |
96f874e2 RR |
8223 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
8224 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 8225 | { |
6711cab4 | 8226 | if (sg) |
6c99e9ad | 8227 | *sg = &per_cpu(sched_group_cpus, cpu).sg; |
1da177e4 LT |
8228 | return cpu; |
8229 | } | |
6d6bc0ad | 8230 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 8231 | |
48f24c4d IM |
8232 | /* |
8233 | * multi-core sched-domains: | |
8234 | */ | |
1e9f28fa | 8235 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
8236 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
8237 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 8238 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
8239 | |
8240 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 8241 | static int |
96f874e2 RR |
8242 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
8243 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 8244 | { |
6711cab4 | 8245 | int group; |
7c16ec58 | 8246 | |
c69fc56d | 8247 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 8248 | group = cpumask_first(mask); |
6711cab4 | 8249 | if (sg) |
6c99e9ad | 8250 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 8251 | return group; |
1e9f28fa SS |
8252 | } |
8253 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 8254 | static int |
96f874e2 RR |
8255 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
8256 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 8257 | { |
6711cab4 | 8258 | if (sg) |
6c99e9ad | 8259 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
8260 | return cpu; |
8261 | } | |
8262 | #endif | |
8263 | ||
6c99e9ad RR |
8264 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
8265 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 8266 | |
41a2d6cf | 8267 | static int |
96f874e2 RR |
8268 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
8269 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 8270 | { |
6711cab4 | 8271 | int group; |
48f24c4d | 8272 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 8273 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 8274 | group = cpumask_first(mask); |
1e9f28fa | 8275 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 8276 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 8277 | group = cpumask_first(mask); |
1da177e4 | 8278 | #else |
6711cab4 | 8279 | group = cpu; |
1da177e4 | 8280 | #endif |
6711cab4 | 8281 | if (sg) |
6c99e9ad | 8282 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 8283 | return group; |
1da177e4 LT |
8284 | } |
8285 | ||
8286 | #ifdef CONFIG_NUMA | |
1da177e4 | 8287 | /* |
9c1cfda2 JH |
8288 | * The init_sched_build_groups can't handle what we want to do with node |
8289 | * groups, so roll our own. Now each node has its own list of groups which | |
8290 | * gets dynamically allocated. | |
1da177e4 | 8291 | */ |
62ea9ceb | 8292 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 8293 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 8294 | |
62ea9ceb | 8295 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 8296 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 8297 | |
96f874e2 RR |
8298 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
8299 | struct sched_group **sg, | |
8300 | struct cpumask *nodemask) | |
9c1cfda2 | 8301 | { |
6711cab4 SS |
8302 | int group; |
8303 | ||
6ca09dfc | 8304 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 8305 | group = cpumask_first(nodemask); |
6711cab4 SS |
8306 | |
8307 | if (sg) | |
6c99e9ad | 8308 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 8309 | return group; |
1da177e4 | 8310 | } |
6711cab4 | 8311 | |
08069033 SS |
8312 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
8313 | { | |
8314 | struct sched_group *sg = group_head; | |
8315 | int j; | |
8316 | ||
8317 | if (!sg) | |
8318 | return; | |
3a5c359a | 8319 | do { |
758b2cdc | 8320 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 8321 | struct sched_domain *sd; |
08069033 | 8322 | |
6c99e9ad | 8323 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 8324 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
8325 | /* |
8326 | * Only add "power" once for each | |
8327 | * physical package. | |
8328 | */ | |
8329 | continue; | |
8330 | } | |
08069033 | 8331 | |
18a3885f | 8332 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
8333 | } |
8334 | sg = sg->next; | |
8335 | } while (sg != group_head); | |
08069033 | 8336 | } |
0601a88d AH |
8337 | |
8338 | static int build_numa_sched_groups(struct s_data *d, | |
8339 | const struct cpumask *cpu_map, int num) | |
8340 | { | |
8341 | struct sched_domain *sd; | |
8342 | struct sched_group *sg, *prev; | |
8343 | int n, j; | |
8344 | ||
8345 | cpumask_clear(d->covered); | |
8346 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
8347 | if (cpumask_empty(d->nodemask)) { | |
8348 | d->sched_group_nodes[num] = NULL; | |
8349 | goto out; | |
8350 | } | |
8351 | ||
8352 | sched_domain_node_span(num, d->domainspan); | |
8353 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
8354 | ||
8355 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
8356 | GFP_KERNEL, num); | |
8357 | if (!sg) { | |
8358 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", | |
8359 | num); | |
8360 | return -ENOMEM; | |
8361 | } | |
8362 | d->sched_group_nodes[num] = sg; | |
8363 | ||
8364 | for_each_cpu(j, d->nodemask) { | |
8365 | sd = &per_cpu(node_domains, j).sd; | |
8366 | sd->groups = sg; | |
8367 | } | |
8368 | ||
18a3885f | 8369 | sg->cpu_power = 0; |
0601a88d AH |
8370 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
8371 | sg->next = sg; | |
8372 | cpumask_or(d->covered, d->covered, d->nodemask); | |
8373 | ||
8374 | prev = sg; | |
8375 | for (j = 0; j < nr_node_ids; j++) { | |
8376 | n = (num + j) % nr_node_ids; | |
8377 | cpumask_complement(d->notcovered, d->covered); | |
8378 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
8379 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
8380 | if (cpumask_empty(d->tmpmask)) | |
8381 | break; | |
8382 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
8383 | if (cpumask_empty(d->tmpmask)) | |
8384 | continue; | |
8385 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
8386 | GFP_KERNEL, num); | |
8387 | if (!sg) { | |
8388 | printk(KERN_WARNING | |
8389 | "Can not alloc domain group for node %d\n", j); | |
8390 | return -ENOMEM; | |
8391 | } | |
18a3885f | 8392 | sg->cpu_power = 0; |
0601a88d AH |
8393 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
8394 | sg->next = prev->next; | |
8395 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
8396 | prev->next = sg; | |
8397 | prev = sg; | |
8398 | } | |
8399 | out: | |
8400 | return 0; | |
8401 | } | |
6d6bc0ad | 8402 | #endif /* CONFIG_NUMA */ |
1da177e4 | 8403 | |
a616058b | 8404 | #ifdef CONFIG_NUMA |
51888ca2 | 8405 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
8406 | static void free_sched_groups(const struct cpumask *cpu_map, |
8407 | struct cpumask *nodemask) | |
51888ca2 | 8408 | { |
a616058b | 8409 | int cpu, i; |
51888ca2 | 8410 | |
abcd083a | 8411 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
8412 | struct sched_group **sched_group_nodes |
8413 | = sched_group_nodes_bycpu[cpu]; | |
8414 | ||
51888ca2 SV |
8415 | if (!sched_group_nodes) |
8416 | continue; | |
8417 | ||
076ac2af | 8418 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
8419 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
8420 | ||
6ca09dfc | 8421 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 8422 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
8423 | continue; |
8424 | ||
8425 | if (sg == NULL) | |
8426 | continue; | |
8427 | sg = sg->next; | |
8428 | next_sg: | |
8429 | oldsg = sg; | |
8430 | sg = sg->next; | |
8431 | kfree(oldsg); | |
8432 | if (oldsg != sched_group_nodes[i]) | |
8433 | goto next_sg; | |
8434 | } | |
8435 | kfree(sched_group_nodes); | |
8436 | sched_group_nodes_bycpu[cpu] = NULL; | |
8437 | } | |
51888ca2 | 8438 | } |
6d6bc0ad | 8439 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
8440 | static void free_sched_groups(const struct cpumask *cpu_map, |
8441 | struct cpumask *nodemask) | |
a616058b SS |
8442 | { |
8443 | } | |
6d6bc0ad | 8444 | #endif /* CONFIG_NUMA */ |
51888ca2 | 8445 | |
89c4710e SS |
8446 | /* |
8447 | * Initialize sched groups cpu_power. | |
8448 | * | |
8449 | * cpu_power indicates the capacity of sched group, which is used while | |
8450 | * distributing the load between different sched groups in a sched domain. | |
8451 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
8452 | * there are asymmetries in the topology. If there are asymmetries, group | |
8453 | * having more cpu_power will pickup more load compared to the group having | |
8454 | * less cpu_power. | |
89c4710e SS |
8455 | */ |
8456 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
8457 | { | |
8458 | struct sched_domain *child; | |
8459 | struct sched_group *group; | |
f93e65c1 PZ |
8460 | long power; |
8461 | int weight; | |
89c4710e SS |
8462 | |
8463 | WARN_ON(!sd || !sd->groups); | |
8464 | ||
13318a71 | 8465 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
8466 | return; |
8467 | ||
8468 | child = sd->child; | |
8469 | ||
18a3885f | 8470 | sd->groups->cpu_power = 0; |
5517d86b | 8471 | |
f93e65c1 PZ |
8472 | if (!child) { |
8473 | power = SCHED_LOAD_SCALE; | |
8474 | weight = cpumask_weight(sched_domain_span(sd)); | |
8475 | /* | |
8476 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
8477 | * Usually multiple threads get a better yield out of |
8478 | * that one core than a single thread would have, | |
8479 | * reflect that in sd->smt_gain. | |
f93e65c1 | 8480 | */ |
a52bfd73 PZ |
8481 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
8482 | power *= sd->smt_gain; | |
f93e65c1 | 8483 | power /= weight; |
a52bfd73 PZ |
8484 | power >>= SCHED_LOAD_SHIFT; |
8485 | } | |
18a3885f | 8486 | sd->groups->cpu_power += power; |
89c4710e SS |
8487 | return; |
8488 | } | |
8489 | ||
89c4710e | 8490 | /* |
f93e65c1 | 8491 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
8492 | */ |
8493 | group = child->groups; | |
8494 | do { | |
18a3885f | 8495 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
8496 | group = group->next; |
8497 | } while (group != child->groups); | |
8498 | } | |
8499 | ||
7c16ec58 MT |
8500 | /* |
8501 | * Initializers for schedule domains | |
8502 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
8503 | */ | |
8504 | ||
a5d8c348 IM |
8505 | #ifdef CONFIG_SCHED_DEBUG |
8506 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
8507 | #else | |
8508 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
8509 | #endif | |
8510 | ||
7c16ec58 | 8511 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 8512 | |
7c16ec58 MT |
8513 | #define SD_INIT_FUNC(type) \ |
8514 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
8515 | { \ | |
8516 | memset(sd, 0, sizeof(*sd)); \ | |
8517 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 8518 | sd->level = SD_LV_##type; \ |
a5d8c348 | 8519 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
8520 | } |
8521 | ||
8522 | SD_INIT_FUNC(CPU) | |
8523 | #ifdef CONFIG_NUMA | |
8524 | SD_INIT_FUNC(ALLNODES) | |
8525 | SD_INIT_FUNC(NODE) | |
8526 | #endif | |
8527 | #ifdef CONFIG_SCHED_SMT | |
8528 | SD_INIT_FUNC(SIBLING) | |
8529 | #endif | |
8530 | #ifdef CONFIG_SCHED_MC | |
8531 | SD_INIT_FUNC(MC) | |
8532 | #endif | |
8533 | ||
1d3504fc HS |
8534 | static int default_relax_domain_level = -1; |
8535 | ||
8536 | static int __init setup_relax_domain_level(char *str) | |
8537 | { | |
30e0e178 LZ |
8538 | unsigned long val; |
8539 | ||
8540 | val = simple_strtoul(str, NULL, 0); | |
8541 | if (val < SD_LV_MAX) | |
8542 | default_relax_domain_level = val; | |
8543 | ||
1d3504fc HS |
8544 | return 1; |
8545 | } | |
8546 | __setup("relax_domain_level=", setup_relax_domain_level); | |
8547 | ||
8548 | static void set_domain_attribute(struct sched_domain *sd, | |
8549 | struct sched_domain_attr *attr) | |
8550 | { | |
8551 | int request; | |
8552 | ||
8553 | if (!attr || attr->relax_domain_level < 0) { | |
8554 | if (default_relax_domain_level < 0) | |
8555 | return; | |
8556 | else | |
8557 | request = default_relax_domain_level; | |
8558 | } else | |
8559 | request = attr->relax_domain_level; | |
8560 | if (request < sd->level) { | |
8561 | /* turn off idle balance on this domain */ | |
8562 | sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); | |
8563 | } else { | |
8564 | /* turn on idle balance on this domain */ | |
8565 | sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); | |
8566 | } | |
8567 | } | |
8568 | ||
2109b99e AH |
8569 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
8570 | const struct cpumask *cpu_map) | |
8571 | { | |
8572 | switch (what) { | |
8573 | case sa_sched_groups: | |
8574 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
8575 | d->sched_group_nodes = NULL; | |
8576 | case sa_rootdomain: | |
8577 | free_rootdomain(d->rd); /* fall through */ | |
8578 | case sa_tmpmask: | |
8579 | free_cpumask_var(d->tmpmask); /* fall through */ | |
8580 | case sa_send_covered: | |
8581 | free_cpumask_var(d->send_covered); /* fall through */ | |
8582 | case sa_this_core_map: | |
8583 | free_cpumask_var(d->this_core_map); /* fall through */ | |
8584 | case sa_this_sibling_map: | |
8585 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
8586 | case sa_nodemask: | |
8587 | free_cpumask_var(d->nodemask); /* fall through */ | |
8588 | case sa_sched_group_nodes: | |
d1b55138 | 8589 | #ifdef CONFIG_NUMA |
2109b99e AH |
8590 | kfree(d->sched_group_nodes); /* fall through */ |
8591 | case sa_notcovered: | |
8592 | free_cpumask_var(d->notcovered); /* fall through */ | |
8593 | case sa_covered: | |
8594 | free_cpumask_var(d->covered); /* fall through */ | |
8595 | case sa_domainspan: | |
8596 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 8597 | #endif |
2109b99e AH |
8598 | case sa_none: |
8599 | break; | |
8600 | } | |
8601 | } | |
3404c8d9 | 8602 | |
2109b99e AH |
8603 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
8604 | const struct cpumask *cpu_map) | |
8605 | { | |
3404c8d9 | 8606 | #ifdef CONFIG_NUMA |
2109b99e AH |
8607 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
8608 | return sa_none; | |
8609 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
8610 | return sa_domainspan; | |
8611 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
8612 | return sa_covered; | |
8613 | /* Allocate the per-node list of sched groups */ | |
8614 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
8615 | sizeof(struct sched_group *), GFP_KERNEL); | |
8616 | if (!d->sched_group_nodes) { | |
d1b55138 | 8617 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 8618 | return sa_notcovered; |
d1b55138 | 8619 | } |
2109b99e | 8620 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 8621 | #endif |
2109b99e AH |
8622 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
8623 | return sa_sched_group_nodes; | |
8624 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
8625 | return sa_nodemask; | |
8626 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
8627 | return sa_this_sibling_map; | |
8628 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
8629 | return sa_this_core_map; | |
8630 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
8631 | return sa_send_covered; | |
8632 | d->rd = alloc_rootdomain(); | |
8633 | if (!d->rd) { | |
57d885fe | 8634 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 8635 | return sa_tmpmask; |
57d885fe | 8636 | } |
2109b99e AH |
8637 | return sa_rootdomain; |
8638 | } | |
57d885fe | 8639 | |
7f4588f3 AH |
8640 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
8641 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
8642 | { | |
8643 | struct sched_domain *sd = NULL; | |
7c16ec58 | 8644 | #ifdef CONFIG_NUMA |
7f4588f3 | 8645 | struct sched_domain *parent; |
1da177e4 | 8646 | |
7f4588f3 AH |
8647 | d->sd_allnodes = 0; |
8648 | if (cpumask_weight(cpu_map) > | |
8649 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
8650 | sd = &per_cpu(allnodes_domains, i).sd; | |
8651 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 8652 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
8653 | cpumask_copy(sched_domain_span(sd), cpu_map); |
8654 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
8655 | d->sd_allnodes = 1; | |
8656 | } | |
8657 | parent = sd; | |
8658 | ||
8659 | sd = &per_cpu(node_domains, i).sd; | |
8660 | SD_INIT(sd, NODE); | |
8661 | set_domain_attribute(sd, attr); | |
8662 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
8663 | sd->parent = parent; | |
8664 | if (parent) | |
8665 | parent->child = sd; | |
8666 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 8667 | #endif |
7f4588f3 AH |
8668 | return sd; |
8669 | } | |
1da177e4 | 8670 | |
87cce662 AH |
8671 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
8672 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8673 | struct sched_domain *parent, int i) | |
8674 | { | |
8675 | struct sched_domain *sd; | |
8676 | sd = &per_cpu(phys_domains, i).sd; | |
8677 | SD_INIT(sd, CPU); | |
8678 | set_domain_attribute(sd, attr); | |
8679 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
8680 | sd->parent = parent; | |
8681 | if (parent) | |
8682 | parent->child = sd; | |
8683 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
8684 | return sd; | |
8685 | } | |
1da177e4 | 8686 | |
410c4081 AH |
8687 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
8688 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8689 | struct sched_domain *parent, int i) | |
8690 | { | |
8691 | struct sched_domain *sd = parent; | |
1e9f28fa | 8692 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
8693 | sd = &per_cpu(core_domains, i).sd; |
8694 | SD_INIT(sd, MC); | |
8695 | set_domain_attribute(sd, attr); | |
8696 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
8697 | sd->parent = parent; | |
8698 | parent->child = sd; | |
8699 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 8700 | #endif |
410c4081 AH |
8701 | return sd; |
8702 | } | |
1e9f28fa | 8703 | |
d8173535 AH |
8704 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
8705 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8706 | struct sched_domain *parent, int i) | |
8707 | { | |
8708 | struct sched_domain *sd = parent; | |
1da177e4 | 8709 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
8710 | sd = &per_cpu(cpu_domains, i).sd; |
8711 | SD_INIT(sd, SIBLING); | |
8712 | set_domain_attribute(sd, attr); | |
8713 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
8714 | sd->parent = parent; | |
8715 | parent->child = sd; | |
8716 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 8717 | #endif |
d8173535 AH |
8718 | return sd; |
8719 | } | |
1da177e4 | 8720 | |
0e8e85c9 AH |
8721 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
8722 | const struct cpumask *cpu_map, int cpu) | |
8723 | { | |
8724 | switch (l) { | |
1da177e4 | 8725 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
8726 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
8727 | cpumask_and(d->this_sibling_map, cpu_map, | |
8728 | topology_thread_cpumask(cpu)); | |
8729 | if (cpu == cpumask_first(d->this_sibling_map)) | |
8730 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
8731 | &cpu_to_cpu_group, | |
8732 | d->send_covered, d->tmpmask); | |
8733 | break; | |
1da177e4 | 8734 | #endif |
1e9f28fa | 8735 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
8736 | case SD_LV_MC: /* set up multi-core groups */ |
8737 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
8738 | if (cpu == cpumask_first(d->this_core_map)) | |
8739 | init_sched_build_groups(d->this_core_map, cpu_map, | |
8740 | &cpu_to_core_group, | |
8741 | d->send_covered, d->tmpmask); | |
8742 | break; | |
1e9f28fa | 8743 | #endif |
86548096 AH |
8744 | case SD_LV_CPU: /* set up physical groups */ |
8745 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
8746 | if (!cpumask_empty(d->nodemask)) | |
8747 | init_sched_build_groups(d->nodemask, cpu_map, | |
8748 | &cpu_to_phys_group, | |
8749 | d->send_covered, d->tmpmask); | |
8750 | break; | |
1da177e4 | 8751 | #ifdef CONFIG_NUMA |
de616e36 AH |
8752 | case SD_LV_ALLNODES: |
8753 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
8754 | d->send_covered, d->tmpmask); | |
8755 | break; | |
8756 | #endif | |
0e8e85c9 AH |
8757 | default: |
8758 | break; | |
7c16ec58 | 8759 | } |
0e8e85c9 | 8760 | } |
9c1cfda2 | 8761 | |
2109b99e AH |
8762 | /* |
8763 | * Build sched domains for a given set of cpus and attach the sched domains | |
8764 | * to the individual cpus | |
8765 | */ | |
8766 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
8767 | struct sched_domain_attr *attr) | |
8768 | { | |
8769 | enum s_alloc alloc_state = sa_none; | |
8770 | struct s_data d; | |
294b0c96 | 8771 | struct sched_domain *sd; |
2109b99e | 8772 | int i; |
7c16ec58 | 8773 | #ifdef CONFIG_NUMA |
2109b99e | 8774 | d.sd_allnodes = 0; |
7c16ec58 | 8775 | #endif |
9c1cfda2 | 8776 | |
2109b99e AH |
8777 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
8778 | if (alloc_state != sa_rootdomain) | |
8779 | goto error; | |
8780 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 8781 | |
1da177e4 | 8782 | /* |
1a20ff27 | 8783 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 8784 | */ |
abcd083a | 8785 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
8786 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
8787 | cpu_map); | |
9761eea8 | 8788 | |
7f4588f3 | 8789 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 8790 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 8791 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 8792 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 8793 | } |
9c1cfda2 | 8794 | |
abcd083a | 8795 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 8796 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 8797 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 8798 | } |
9c1cfda2 | 8799 | |
1da177e4 | 8800 | /* Set up physical groups */ |
86548096 AH |
8801 | for (i = 0; i < nr_node_ids; i++) |
8802 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 8803 | |
1da177e4 LT |
8804 | #ifdef CONFIG_NUMA |
8805 | /* Set up node groups */ | |
de616e36 AH |
8806 | if (d.sd_allnodes) |
8807 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 8808 | |
0601a88d AH |
8809 | for (i = 0; i < nr_node_ids; i++) |
8810 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 8811 | goto error; |
1da177e4 LT |
8812 | #endif |
8813 | ||
8814 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 8815 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 8816 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8817 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 8818 | init_sched_groups_power(i, sd); |
5c45bf27 | 8819 | } |
1da177e4 | 8820 | #endif |
1e9f28fa | 8821 | #ifdef CONFIG_SCHED_MC |
abcd083a | 8822 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8823 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 8824 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
8825 | } |
8826 | #endif | |
1e9f28fa | 8827 | |
abcd083a | 8828 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8829 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 8830 | init_sched_groups_power(i, sd); |
1da177e4 LT |
8831 | } |
8832 | ||
9c1cfda2 | 8833 | #ifdef CONFIG_NUMA |
076ac2af | 8834 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 8835 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 8836 | |
49a02c51 | 8837 | if (d.sd_allnodes) { |
6711cab4 | 8838 | struct sched_group *sg; |
f712c0c7 | 8839 | |
96f874e2 | 8840 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 8841 | d.tmpmask); |
f712c0c7 SS |
8842 | init_numa_sched_groups_power(sg); |
8843 | } | |
9c1cfda2 JH |
8844 | #endif |
8845 | ||
1da177e4 | 8846 | /* Attach the domains */ |
abcd083a | 8847 | for_each_cpu(i, cpu_map) { |
1da177e4 | 8848 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 8849 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 8850 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 8851 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 8852 | #else |
6c99e9ad | 8853 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 8854 | #endif |
49a02c51 | 8855 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 8856 | } |
51888ca2 | 8857 | |
2109b99e AH |
8858 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
8859 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
8860 | return 0; | |
51888ca2 | 8861 | |
51888ca2 | 8862 | error: |
2109b99e AH |
8863 | __free_domain_allocs(&d, alloc_state, cpu_map); |
8864 | return -ENOMEM; | |
1da177e4 | 8865 | } |
029190c5 | 8866 | |
96f874e2 | 8867 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
8868 | { |
8869 | return __build_sched_domains(cpu_map, NULL); | |
8870 | } | |
8871 | ||
96f874e2 | 8872 | static struct cpumask *doms_cur; /* current sched domains */ |
029190c5 | 8873 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
8874 | static struct sched_domain_attr *dattr_cur; |
8875 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
8876 | |
8877 | /* | |
8878 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
8879 | * cpumask) fails, then fallback to a single sched domain, |
8880 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 8881 | */ |
4212823f | 8882 | static cpumask_var_t fallback_doms; |
029190c5 | 8883 | |
ee79d1bd HC |
8884 | /* |
8885 | * arch_update_cpu_topology lets virtualized architectures update the | |
8886 | * cpu core maps. It is supposed to return 1 if the topology changed | |
8887 | * or 0 if it stayed the same. | |
8888 | */ | |
8889 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 8890 | { |
ee79d1bd | 8891 | return 0; |
22e52b07 HC |
8892 | } |
8893 | ||
1a20ff27 | 8894 | /* |
41a2d6cf | 8895 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
8896 | * For now this just excludes isolated cpus, but could be used to |
8897 | * exclude other special cases in the future. | |
1a20ff27 | 8898 | */ |
96f874e2 | 8899 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 8900 | { |
7378547f MM |
8901 | int err; |
8902 | ||
22e52b07 | 8903 | arch_update_cpu_topology(); |
029190c5 | 8904 | ndoms_cur = 1; |
96f874e2 | 8905 | doms_cur = kmalloc(cpumask_size(), GFP_KERNEL); |
029190c5 | 8906 | if (!doms_cur) |
4212823f | 8907 | doms_cur = fallback_doms; |
dcc30a35 | 8908 | cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map); |
1d3504fc | 8909 | dattr_cur = NULL; |
7378547f | 8910 | err = build_sched_domains(doms_cur); |
6382bc90 | 8911 | register_sched_domain_sysctl(); |
7378547f MM |
8912 | |
8913 | return err; | |
1a20ff27 DG |
8914 | } |
8915 | ||
96f874e2 RR |
8916 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
8917 | struct cpumask *tmpmask) | |
1da177e4 | 8918 | { |
7c16ec58 | 8919 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 8920 | } |
1da177e4 | 8921 | |
1a20ff27 DG |
8922 | /* |
8923 | * Detach sched domains from a group of cpus specified in cpu_map | |
8924 | * These cpus will now be attached to the NULL domain | |
8925 | */ | |
96f874e2 | 8926 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 8927 | { |
96f874e2 RR |
8928 | /* Save because hotplug lock held. */ |
8929 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
8930 | int i; |
8931 | ||
abcd083a | 8932 | for_each_cpu(i, cpu_map) |
57d885fe | 8933 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 8934 | synchronize_sched(); |
96f874e2 | 8935 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
8936 | } |
8937 | ||
1d3504fc HS |
8938 | /* handle null as "default" */ |
8939 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
8940 | struct sched_domain_attr *new, int idx_new) | |
8941 | { | |
8942 | struct sched_domain_attr tmp; | |
8943 | ||
8944 | /* fast path */ | |
8945 | if (!new && !cur) | |
8946 | return 1; | |
8947 | ||
8948 | tmp = SD_ATTR_INIT; | |
8949 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
8950 | new ? (new + idx_new) : &tmp, | |
8951 | sizeof(struct sched_domain_attr)); | |
8952 | } | |
8953 | ||
029190c5 PJ |
8954 | /* |
8955 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 8956 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
8957 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
8958 | * It destroys each deleted domain and builds each new domain. | |
8959 | * | |
96f874e2 | 8960 | * 'doms_new' is an array of cpumask's of length 'ndoms_new'. |
41a2d6cf IM |
8961 | * The masks don't intersect (don't overlap.) We should setup one |
8962 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
8963 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
8964 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
8965 | * it as it is. | |
8966 | * | |
41a2d6cf IM |
8967 | * The passed in 'doms_new' should be kmalloc'd. This routine takes |
8968 | * ownership of it and will kfree it when done with it. If the caller | |
700018e0 LZ |
8969 | * failed the kmalloc call, then it can pass in doms_new == NULL && |
8970 | * ndoms_new == 1, and partition_sched_domains() will fallback to | |
8971 | * the single partition 'fallback_doms', it also forces the domains | |
8972 | * to be rebuilt. | |
029190c5 | 8973 | * |
96f874e2 | 8974 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
8975 | * ndoms_new == 0 is a special case for destroying existing domains, |
8976 | * and it will not create the default domain. | |
dfb512ec | 8977 | * |
029190c5 PJ |
8978 | * Call with hotplug lock held |
8979 | */ | |
96f874e2 RR |
8980 | /* FIXME: Change to struct cpumask *doms_new[] */ |
8981 | void partition_sched_domains(int ndoms_new, struct cpumask *doms_new, | |
1d3504fc | 8982 | struct sched_domain_attr *dattr_new) |
029190c5 | 8983 | { |
dfb512ec | 8984 | int i, j, n; |
d65bd5ec | 8985 | int new_topology; |
029190c5 | 8986 | |
712555ee | 8987 | mutex_lock(&sched_domains_mutex); |
a1835615 | 8988 | |
7378547f MM |
8989 | /* always unregister in case we don't destroy any domains */ |
8990 | unregister_sched_domain_sysctl(); | |
8991 | ||
d65bd5ec HC |
8992 | /* Let architecture update cpu core mappings. */ |
8993 | new_topology = arch_update_cpu_topology(); | |
8994 | ||
dfb512ec | 8995 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
8996 | |
8997 | /* Destroy deleted domains */ | |
8998 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 8999 | for (j = 0; j < n && !new_topology; j++) { |
96f874e2 | 9000 | if (cpumask_equal(&doms_cur[i], &doms_new[j]) |
1d3504fc | 9001 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
9002 | goto match1; |
9003 | } | |
9004 | /* no match - a current sched domain not in new doms_new[] */ | |
9005 | detach_destroy_domains(doms_cur + i); | |
9006 | match1: | |
9007 | ; | |
9008 | } | |
9009 | ||
e761b772 MK |
9010 | if (doms_new == NULL) { |
9011 | ndoms_cur = 0; | |
4212823f | 9012 | doms_new = fallback_doms; |
dcc30a35 | 9013 | cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map); |
faa2f98f | 9014 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
9015 | } |
9016 | ||
029190c5 PJ |
9017 | /* Build new domains */ |
9018 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 9019 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
96f874e2 | 9020 | if (cpumask_equal(&doms_new[i], &doms_cur[j]) |
1d3504fc | 9021 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
9022 | goto match2; |
9023 | } | |
9024 | /* no match - add a new doms_new */ | |
1d3504fc HS |
9025 | __build_sched_domains(doms_new + i, |
9026 | dattr_new ? dattr_new + i : NULL); | |
029190c5 PJ |
9027 | match2: |
9028 | ; | |
9029 | } | |
9030 | ||
9031 | /* Remember the new sched domains */ | |
4212823f | 9032 | if (doms_cur != fallback_doms) |
029190c5 | 9033 | kfree(doms_cur); |
1d3504fc | 9034 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 9035 | doms_cur = doms_new; |
1d3504fc | 9036 | dattr_cur = dattr_new; |
029190c5 | 9037 | ndoms_cur = ndoms_new; |
7378547f MM |
9038 | |
9039 | register_sched_domain_sysctl(); | |
a1835615 | 9040 | |
712555ee | 9041 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
9042 | } |
9043 | ||
5c45bf27 | 9044 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 9045 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 9046 | { |
95402b38 | 9047 | get_online_cpus(); |
dfb512ec MK |
9048 | |
9049 | /* Destroy domains first to force the rebuild */ | |
9050 | partition_sched_domains(0, NULL, NULL); | |
9051 | ||
e761b772 | 9052 | rebuild_sched_domains(); |
95402b38 | 9053 | put_online_cpus(); |
5c45bf27 SS |
9054 | } |
9055 | ||
9056 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
9057 | { | |
afb8a9b7 | 9058 | unsigned int level = 0; |
5c45bf27 | 9059 | |
afb8a9b7 GS |
9060 | if (sscanf(buf, "%u", &level) != 1) |
9061 | return -EINVAL; | |
9062 | ||
9063 | /* | |
9064 | * level is always be positive so don't check for | |
9065 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
9066 | * What happens on 0 or 1 byte write, | |
9067 | * need to check for count as well? | |
9068 | */ | |
9069 | ||
9070 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
9071 | return -EINVAL; |
9072 | ||
9073 | if (smt) | |
afb8a9b7 | 9074 | sched_smt_power_savings = level; |
5c45bf27 | 9075 | else |
afb8a9b7 | 9076 | sched_mc_power_savings = level; |
5c45bf27 | 9077 | |
c70f22d2 | 9078 | arch_reinit_sched_domains(); |
5c45bf27 | 9079 | |
c70f22d2 | 9080 | return count; |
5c45bf27 SS |
9081 | } |
9082 | ||
5c45bf27 | 9083 | #ifdef CONFIG_SCHED_MC |
f718cd4a AK |
9084 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
9085 | char *page) | |
5c45bf27 SS |
9086 | { |
9087 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
9088 | } | |
f718cd4a | 9089 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
48f24c4d | 9090 | const char *buf, size_t count) |
5c45bf27 SS |
9091 | { |
9092 | return sched_power_savings_store(buf, count, 0); | |
9093 | } | |
f718cd4a AK |
9094 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
9095 | sched_mc_power_savings_show, | |
9096 | sched_mc_power_savings_store); | |
5c45bf27 SS |
9097 | #endif |
9098 | ||
9099 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a AK |
9100 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
9101 | char *page) | |
5c45bf27 SS |
9102 | { |
9103 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
9104 | } | |
f718cd4a | 9105 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
48f24c4d | 9106 | const char *buf, size_t count) |
5c45bf27 SS |
9107 | { |
9108 | return sched_power_savings_store(buf, count, 1); | |
9109 | } | |
f718cd4a AK |
9110 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
9111 | sched_smt_power_savings_show, | |
6707de00 AB |
9112 | sched_smt_power_savings_store); |
9113 | #endif | |
9114 | ||
39aac648 | 9115 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
9116 | { |
9117 | int err = 0; | |
9118 | ||
9119 | #ifdef CONFIG_SCHED_SMT | |
9120 | if (smt_capable()) | |
9121 | err = sysfs_create_file(&cls->kset.kobj, | |
9122 | &attr_sched_smt_power_savings.attr); | |
9123 | #endif | |
9124 | #ifdef CONFIG_SCHED_MC | |
9125 | if (!err && mc_capable()) | |
9126 | err = sysfs_create_file(&cls->kset.kobj, | |
9127 | &attr_sched_mc_power_savings.attr); | |
9128 | #endif | |
9129 | return err; | |
9130 | } | |
6d6bc0ad | 9131 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 9132 | |
e761b772 | 9133 | #ifndef CONFIG_CPUSETS |
1da177e4 | 9134 | /* |
e761b772 MK |
9135 | * Add online and remove offline CPUs from the scheduler domains. |
9136 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
9137 | */ |
9138 | static int update_sched_domains(struct notifier_block *nfb, | |
9139 | unsigned long action, void *hcpu) | |
e761b772 MK |
9140 | { |
9141 | switch (action) { | |
9142 | case CPU_ONLINE: | |
9143 | case CPU_ONLINE_FROZEN: | |
9144 | case CPU_DEAD: | |
9145 | case CPU_DEAD_FROZEN: | |
dfb512ec | 9146 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
9147 | return NOTIFY_OK; |
9148 | ||
9149 | default: | |
9150 | return NOTIFY_DONE; | |
9151 | } | |
9152 | } | |
9153 | #endif | |
9154 | ||
9155 | static int update_runtime(struct notifier_block *nfb, | |
9156 | unsigned long action, void *hcpu) | |
1da177e4 | 9157 | { |
7def2be1 PZ |
9158 | int cpu = (int)(long)hcpu; |
9159 | ||
1da177e4 | 9160 | switch (action) { |
1da177e4 | 9161 | case CPU_DOWN_PREPARE: |
8bb78442 | 9162 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 9163 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
9164 | return NOTIFY_OK; |
9165 | ||
1da177e4 | 9166 | case CPU_DOWN_FAILED: |
8bb78442 | 9167 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 9168 | case CPU_ONLINE: |
8bb78442 | 9169 | case CPU_ONLINE_FROZEN: |
7def2be1 | 9170 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
9171 | return NOTIFY_OK; |
9172 | ||
1da177e4 LT |
9173 | default: |
9174 | return NOTIFY_DONE; | |
9175 | } | |
1da177e4 | 9176 | } |
1da177e4 LT |
9177 | |
9178 | void __init sched_init_smp(void) | |
9179 | { | |
dcc30a35 RR |
9180 | cpumask_var_t non_isolated_cpus; |
9181 | ||
9182 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
5c1e1767 | 9183 | |
434d53b0 MT |
9184 | #if defined(CONFIG_NUMA) |
9185 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
9186 | GFP_KERNEL); | |
9187 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
9188 | #endif | |
95402b38 | 9189 | get_online_cpus(); |
712555ee | 9190 | mutex_lock(&sched_domains_mutex); |
dcc30a35 RR |
9191 | arch_init_sched_domains(cpu_online_mask); |
9192 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); | |
9193 | if (cpumask_empty(non_isolated_cpus)) | |
9194 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 9195 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 9196 | put_online_cpus(); |
e761b772 MK |
9197 | |
9198 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
9199 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
9200 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
9201 | #endif |
9202 | ||
9203 | /* RT runtime code needs to handle some hotplug events */ | |
9204 | hotcpu_notifier(update_runtime, 0); | |
9205 | ||
b328ca18 | 9206 | init_hrtick(); |
5c1e1767 NP |
9207 | |
9208 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 9209 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 9210 | BUG(); |
19978ca6 | 9211 | sched_init_granularity(); |
dcc30a35 | 9212 | free_cpumask_var(non_isolated_cpus); |
4212823f RR |
9213 | |
9214 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); | |
0e3900e6 | 9215 | init_sched_rt_class(); |
1da177e4 LT |
9216 | } |
9217 | #else | |
9218 | void __init sched_init_smp(void) | |
9219 | { | |
19978ca6 | 9220 | sched_init_granularity(); |
1da177e4 LT |
9221 | } |
9222 | #endif /* CONFIG_SMP */ | |
9223 | ||
cd1bb94b AB |
9224 | const_debug unsigned int sysctl_timer_migration = 1; |
9225 | ||
1da177e4 LT |
9226 | int in_sched_functions(unsigned long addr) |
9227 | { | |
1da177e4 LT |
9228 | return in_lock_functions(addr) || |
9229 | (addr >= (unsigned long)__sched_text_start | |
9230 | && addr < (unsigned long)__sched_text_end); | |
9231 | } | |
9232 | ||
a9957449 | 9233 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
9234 | { |
9235 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 9236 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
9237 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9238 | cfs_rq->rq = rq; | |
9239 | #endif | |
67e9fb2a | 9240 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
9241 | } |
9242 | ||
fa85ae24 PZ |
9243 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
9244 | { | |
9245 | struct rt_prio_array *array; | |
9246 | int i; | |
9247 | ||
9248 | array = &rt_rq->active; | |
9249 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
9250 | INIT_LIST_HEAD(array->queue + i); | |
9251 | __clear_bit(i, array->bitmap); | |
9252 | } | |
9253 | /* delimiter for bitsearch: */ | |
9254 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
9255 | ||
052f1dc7 | 9256 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 9257 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 9258 | #ifdef CONFIG_SMP |
e864c499 | 9259 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 9260 | #endif |
48d5e258 | 9261 | #endif |
fa85ae24 PZ |
9262 | #ifdef CONFIG_SMP |
9263 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 9264 | rt_rq->overloaded = 0; |
c20b08e3 | 9265 | plist_head_init(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
9266 | #endif |
9267 | ||
9268 | rt_rq->rt_time = 0; | |
9269 | rt_rq->rt_throttled = 0; | |
ac086bc2 PZ |
9270 | rt_rq->rt_runtime = 0; |
9271 | spin_lock_init(&rt_rq->rt_runtime_lock); | |
6f505b16 | 9272 | |
052f1dc7 | 9273 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 9274 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
9275 | rt_rq->rq = rq; |
9276 | #endif | |
fa85ae24 PZ |
9277 | } |
9278 | ||
6f505b16 | 9279 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
9280 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
9281 | struct sched_entity *se, int cpu, int add, | |
9282 | struct sched_entity *parent) | |
6f505b16 | 9283 | { |
ec7dc8ac | 9284 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
9285 | tg->cfs_rq[cpu] = cfs_rq; |
9286 | init_cfs_rq(cfs_rq, rq); | |
9287 | cfs_rq->tg = tg; | |
9288 | if (add) | |
9289 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
9290 | ||
9291 | tg->se[cpu] = se; | |
354d60c2 DG |
9292 | /* se could be NULL for init_task_group */ |
9293 | if (!se) | |
9294 | return; | |
9295 | ||
ec7dc8ac DG |
9296 | if (!parent) |
9297 | se->cfs_rq = &rq->cfs; | |
9298 | else | |
9299 | se->cfs_rq = parent->my_q; | |
9300 | ||
6f505b16 PZ |
9301 | se->my_q = cfs_rq; |
9302 | se->load.weight = tg->shares; | |
e05510d0 | 9303 | se->load.inv_weight = 0; |
ec7dc8ac | 9304 | se->parent = parent; |
6f505b16 | 9305 | } |
052f1dc7 | 9306 | #endif |
6f505b16 | 9307 | |
052f1dc7 | 9308 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
9309 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
9310 | struct sched_rt_entity *rt_se, int cpu, int add, | |
9311 | struct sched_rt_entity *parent) | |
6f505b16 | 9312 | { |
ec7dc8ac DG |
9313 | struct rq *rq = cpu_rq(cpu); |
9314 | ||
6f505b16 PZ |
9315 | tg->rt_rq[cpu] = rt_rq; |
9316 | init_rt_rq(rt_rq, rq); | |
9317 | rt_rq->tg = tg; | |
9318 | rt_rq->rt_se = rt_se; | |
ac086bc2 | 9319 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
9320 | if (add) |
9321 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
9322 | ||
9323 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
9324 | if (!rt_se) |
9325 | return; | |
9326 | ||
ec7dc8ac DG |
9327 | if (!parent) |
9328 | rt_se->rt_rq = &rq->rt; | |
9329 | else | |
9330 | rt_se->rt_rq = parent->my_q; | |
9331 | ||
6f505b16 | 9332 | rt_se->my_q = rt_rq; |
ec7dc8ac | 9333 | rt_se->parent = parent; |
6f505b16 PZ |
9334 | INIT_LIST_HEAD(&rt_se->run_list); |
9335 | } | |
9336 | #endif | |
9337 | ||
1da177e4 LT |
9338 | void __init sched_init(void) |
9339 | { | |
dd41f596 | 9340 | int i, j; |
434d53b0 MT |
9341 | unsigned long alloc_size = 0, ptr; |
9342 | ||
9343 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
9344 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
9345 | #endif | |
9346 | #ifdef CONFIG_RT_GROUP_SCHED | |
9347 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
9348 | #endif |
9349 | #ifdef CONFIG_USER_SCHED | |
9350 | alloc_size *= 2; | |
df7c8e84 RR |
9351 | #endif |
9352 | #ifdef CONFIG_CPUMASK_OFFSTACK | |
8c083f08 | 9353 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 MT |
9354 | #endif |
9355 | /* | |
9356 | * As sched_init() is called before page_alloc is setup, | |
9357 | * we use alloc_bootmem(). | |
9358 | */ | |
9359 | if (alloc_size) { | |
36b7b6d4 | 9360 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
9361 | |
9362 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
9363 | init_task_group.se = (struct sched_entity **)ptr; | |
9364 | ptr += nr_cpu_ids * sizeof(void **); | |
9365 | ||
9366 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
9367 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
9368 | |
9369 | #ifdef CONFIG_USER_SCHED | |
9370 | root_task_group.se = (struct sched_entity **)ptr; | |
9371 | ptr += nr_cpu_ids * sizeof(void **); | |
9372 | ||
9373 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
9374 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
9375 | #endif /* CONFIG_USER_SCHED */ |
9376 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
434d53b0 MT |
9377 | #ifdef CONFIG_RT_GROUP_SCHED |
9378 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
9379 | ptr += nr_cpu_ids * sizeof(void **); | |
9380 | ||
9381 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
9382 | ptr += nr_cpu_ids * sizeof(void **); |
9383 | ||
9384 | #ifdef CONFIG_USER_SCHED | |
9385 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
9386 | ptr += nr_cpu_ids * sizeof(void **); | |
9387 | ||
9388 | root_task_group.rt_rq = (struct rt_rq **)ptr; | |
9389 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
9390 | #endif /* CONFIG_USER_SCHED */ |
9391 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
df7c8e84 RR |
9392 | #ifdef CONFIG_CPUMASK_OFFSTACK |
9393 | for_each_possible_cpu(i) { | |
9394 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
9395 | ptr += cpumask_size(); | |
9396 | } | |
9397 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 9398 | } |
dd41f596 | 9399 | |
57d885fe GH |
9400 | #ifdef CONFIG_SMP |
9401 | init_defrootdomain(); | |
9402 | #endif | |
9403 | ||
d0b27fa7 PZ |
9404 | init_rt_bandwidth(&def_rt_bandwidth, |
9405 | global_rt_period(), global_rt_runtime()); | |
9406 | ||
9407 | #ifdef CONFIG_RT_GROUP_SCHED | |
9408 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
9409 | global_rt_period(), global_rt_runtime()); | |
eff766a6 PZ |
9410 | #ifdef CONFIG_USER_SCHED |
9411 | init_rt_bandwidth(&root_task_group.rt_bandwidth, | |
9412 | global_rt_period(), RUNTIME_INF); | |
6d6bc0ad DG |
9413 | #endif /* CONFIG_USER_SCHED */ |
9414 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
d0b27fa7 | 9415 | |
052f1dc7 | 9416 | #ifdef CONFIG_GROUP_SCHED |
6f505b16 | 9417 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
9418 | INIT_LIST_HEAD(&init_task_group.children); |
9419 | ||
9420 | #ifdef CONFIG_USER_SCHED | |
9421 | INIT_LIST_HEAD(&root_task_group.children); | |
9422 | init_task_group.parent = &root_task_group; | |
9423 | list_add(&init_task_group.siblings, &root_task_group.children); | |
6d6bc0ad DG |
9424 | #endif /* CONFIG_USER_SCHED */ |
9425 | #endif /* CONFIG_GROUP_SCHED */ | |
6f505b16 | 9426 | |
0a945022 | 9427 | for_each_possible_cpu(i) { |
70b97a7f | 9428 | struct rq *rq; |
1da177e4 LT |
9429 | |
9430 | rq = cpu_rq(i); | |
9431 | spin_lock_init(&rq->lock); | |
7897986b | 9432 | rq->nr_running = 0; |
dce48a84 TG |
9433 | rq->calc_load_active = 0; |
9434 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 9435 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 9436 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 9437 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 9438 | init_task_group.shares = init_task_group_load; |
6f505b16 | 9439 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
9440 | #ifdef CONFIG_CGROUP_SCHED |
9441 | /* | |
9442 | * How much cpu bandwidth does init_task_group get? | |
9443 | * | |
9444 | * In case of task-groups formed thr' the cgroup filesystem, it | |
9445 | * gets 100% of the cpu resources in the system. This overall | |
9446 | * system cpu resource is divided among the tasks of | |
9447 | * init_task_group and its child task-groups in a fair manner, | |
9448 | * based on each entity's (task or task-group's) weight | |
9449 | * (se->load.weight). | |
9450 | * | |
9451 | * In other words, if init_task_group has 10 tasks of weight | |
9452 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
9453 | * then A0's share of the cpu resource is: | |
9454 | * | |
0d905bca | 9455 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
9456 | * |
9457 | * We achieve this by letting init_task_group's tasks sit | |
9458 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
9459 | */ | |
ec7dc8ac | 9460 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
354d60c2 | 9461 | #elif defined CONFIG_USER_SCHED |
eff766a6 PZ |
9462 | root_task_group.shares = NICE_0_LOAD; |
9463 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); | |
354d60c2 DG |
9464 | /* |
9465 | * In case of task-groups formed thr' the user id of tasks, | |
9466 | * init_task_group represents tasks belonging to root user. | |
9467 | * Hence it forms a sibling of all subsequent groups formed. | |
9468 | * In this case, init_task_group gets only a fraction of overall | |
9469 | * system cpu resource, based on the weight assigned to root | |
9470 | * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished | |
9471 | * by letting tasks of init_task_group sit in a separate cfs_rq | |
84e9dabf | 9472 | * (init_tg_cfs_rq) and having one entity represent this group of |
354d60c2 DG |
9473 | * tasks in rq->cfs (i.e init_task_group->se[] != NULL). |
9474 | */ | |
ec7dc8ac | 9475 | init_tg_cfs_entry(&init_task_group, |
84e9dabf | 9476 | &per_cpu(init_tg_cfs_rq, i), |
eff766a6 PZ |
9477 | &per_cpu(init_sched_entity, i), i, 1, |
9478 | root_task_group.se[i]); | |
6f505b16 | 9479 | |
052f1dc7 | 9480 | #endif |
354d60c2 DG |
9481 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
9482 | ||
9483 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 9484 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9485 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 9486 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 9487 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 9488 | #elif defined CONFIG_USER_SCHED |
eff766a6 | 9489 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); |
ec7dc8ac | 9490 | init_tg_rt_entry(&init_task_group, |
6f505b16 | 9491 | &per_cpu(init_rt_rq, i), |
eff766a6 PZ |
9492 | &per_cpu(init_sched_rt_entity, i), i, 1, |
9493 | root_task_group.rt_se[i]); | |
354d60c2 | 9494 | #endif |
dd41f596 | 9495 | #endif |
1da177e4 | 9496 | |
dd41f596 IM |
9497 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
9498 | rq->cpu_load[j] = 0; | |
1da177e4 | 9499 | #ifdef CONFIG_SMP |
41c7ce9a | 9500 | rq->sd = NULL; |
57d885fe | 9501 | rq->rd = NULL; |
3f029d3c | 9502 | rq->post_schedule = 0; |
1da177e4 | 9503 | rq->active_balance = 0; |
dd41f596 | 9504 | rq->next_balance = jiffies; |
1da177e4 | 9505 | rq->push_cpu = 0; |
0a2966b4 | 9506 | rq->cpu = i; |
1f11eb6a | 9507 | rq->online = 0; |
1da177e4 LT |
9508 | rq->migration_thread = NULL; |
9509 | INIT_LIST_HEAD(&rq->migration_queue); | |
dc938520 | 9510 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 9511 | #endif |
8f4d37ec | 9512 | init_rq_hrtick(rq); |
1da177e4 | 9513 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
9514 | } |
9515 | ||
2dd73a4f | 9516 | set_load_weight(&init_task); |
b50f60ce | 9517 | |
e107be36 AK |
9518 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
9519 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
9520 | #endif | |
9521 | ||
c9819f45 | 9522 | #ifdef CONFIG_SMP |
962cf36c | 9523 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
9524 | #endif |
9525 | ||
b50f60ce HC |
9526 | #ifdef CONFIG_RT_MUTEXES |
9527 | plist_head_init(&init_task.pi_waiters, &init_task.pi_lock); | |
9528 | #endif | |
9529 | ||
1da177e4 LT |
9530 | /* |
9531 | * The boot idle thread does lazy MMU switching as well: | |
9532 | */ | |
9533 | atomic_inc(&init_mm.mm_count); | |
9534 | enter_lazy_tlb(&init_mm, current); | |
9535 | ||
9536 | /* | |
9537 | * Make us the idle thread. Technically, schedule() should not be | |
9538 | * called from this thread, however somewhere below it might be, | |
9539 | * but because we are the idle thread, we just pick up running again | |
9540 | * when this runqueue becomes "idle". | |
9541 | */ | |
9542 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
9543 | |
9544 | calc_load_update = jiffies + LOAD_FREQ; | |
9545 | ||
dd41f596 IM |
9546 | /* |
9547 | * During early bootup we pretend to be a normal task: | |
9548 | */ | |
9549 | current->sched_class = &fair_sched_class; | |
6892b75e | 9550 | |
6a7b3dc3 | 9551 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
4bdddf8f | 9552 | alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 9553 | #ifdef CONFIG_SMP |
7d1e6a9b | 9554 | #ifdef CONFIG_NO_HZ |
4bdddf8f PE |
9555 | alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); |
9556 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); | |
7d1e6a9b | 9557 | #endif |
4bdddf8f | 9558 | alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); |
bf4d83f6 | 9559 | #endif /* SMP */ |
6a7b3dc3 | 9560 | |
0d905bca IM |
9561 | perf_counter_init(); |
9562 | ||
6892b75e | 9563 | scheduler_running = 1; |
1da177e4 LT |
9564 | } |
9565 | ||
9566 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
9567 | static inline int preempt_count_equals(int preempt_offset) |
9568 | { | |
9569 | int nested = preempt_count() & ~PREEMPT_ACTIVE; | |
9570 | ||
9571 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
9572 | } | |
9573 | ||
9574 | void __might_sleep(char *file, int line, int preempt_offset) | |
1da177e4 | 9575 | { |
48f24c4d | 9576 | #ifdef in_atomic |
1da177e4 LT |
9577 | static unsigned long prev_jiffy; /* ratelimiting */ |
9578 | ||
e4aafea2 FW |
9579 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
9580 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
9581 | return; |
9582 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
9583 | return; | |
9584 | prev_jiffy = jiffies; | |
9585 | ||
9586 | printk(KERN_ERR | |
9587 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
9588 | file, line); | |
9589 | printk(KERN_ERR | |
9590 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
9591 | in_atomic(), irqs_disabled(), | |
9592 | current->pid, current->comm); | |
9593 | ||
9594 | debug_show_held_locks(current); | |
9595 | if (irqs_disabled()) | |
9596 | print_irqtrace_events(current); | |
9597 | dump_stack(); | |
1da177e4 LT |
9598 | #endif |
9599 | } | |
9600 | EXPORT_SYMBOL(__might_sleep); | |
9601 | #endif | |
9602 | ||
9603 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
9604 | static void normalize_task(struct rq *rq, struct task_struct *p) |
9605 | { | |
9606 | int on_rq; | |
3e51f33f | 9607 | |
3a5e4dc1 AK |
9608 | update_rq_clock(rq); |
9609 | on_rq = p->se.on_rq; | |
9610 | if (on_rq) | |
9611 | deactivate_task(rq, p, 0); | |
9612 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
9613 | if (on_rq) { | |
9614 | activate_task(rq, p, 0); | |
9615 | resched_task(rq->curr); | |
9616 | } | |
9617 | } | |
9618 | ||
1da177e4 LT |
9619 | void normalize_rt_tasks(void) |
9620 | { | |
a0f98a1c | 9621 | struct task_struct *g, *p; |
1da177e4 | 9622 | unsigned long flags; |
70b97a7f | 9623 | struct rq *rq; |
1da177e4 | 9624 | |
4cf5d77a | 9625 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 9626 | do_each_thread(g, p) { |
178be793 IM |
9627 | /* |
9628 | * Only normalize user tasks: | |
9629 | */ | |
9630 | if (!p->mm) | |
9631 | continue; | |
9632 | ||
6cfb0d5d | 9633 | p->se.exec_start = 0; |
6cfb0d5d | 9634 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 9635 | p->se.wait_start = 0; |
dd41f596 | 9636 | p->se.sleep_start = 0; |
dd41f596 | 9637 | p->se.block_start = 0; |
6cfb0d5d | 9638 | #endif |
dd41f596 IM |
9639 | |
9640 | if (!rt_task(p)) { | |
9641 | /* | |
9642 | * Renice negative nice level userspace | |
9643 | * tasks back to 0: | |
9644 | */ | |
9645 | if (TASK_NICE(p) < 0 && p->mm) | |
9646 | set_user_nice(p, 0); | |
1da177e4 | 9647 | continue; |
dd41f596 | 9648 | } |
1da177e4 | 9649 | |
4cf5d77a | 9650 | spin_lock(&p->pi_lock); |
b29739f9 | 9651 | rq = __task_rq_lock(p); |
1da177e4 | 9652 | |
178be793 | 9653 | normalize_task(rq, p); |
3a5e4dc1 | 9654 | |
b29739f9 | 9655 | __task_rq_unlock(rq); |
4cf5d77a | 9656 | spin_unlock(&p->pi_lock); |
a0f98a1c IM |
9657 | } while_each_thread(g, p); |
9658 | ||
4cf5d77a | 9659 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
9660 | } |
9661 | ||
9662 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
9663 | |
9664 | #ifdef CONFIG_IA64 | |
9665 | /* | |
9666 | * These functions are only useful for the IA64 MCA handling. | |
9667 | * | |
9668 | * They can only be called when the whole system has been | |
9669 | * stopped - every CPU needs to be quiescent, and no scheduling | |
9670 | * activity can take place. Using them for anything else would | |
9671 | * be a serious bug, and as a result, they aren't even visible | |
9672 | * under any other configuration. | |
9673 | */ | |
9674 | ||
9675 | /** | |
9676 | * curr_task - return the current task for a given cpu. | |
9677 | * @cpu: the processor in question. | |
9678 | * | |
9679 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
9680 | */ | |
36c8b586 | 9681 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
9682 | { |
9683 | return cpu_curr(cpu); | |
9684 | } | |
9685 | ||
9686 | /** | |
9687 | * set_curr_task - set the current task for a given cpu. | |
9688 | * @cpu: the processor in question. | |
9689 | * @p: the task pointer to set. | |
9690 | * | |
9691 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
9692 | * are serviced on a separate stack. It allows the architecture to switch the |
9693 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
9694 | * must be called with all CPU's synchronized, and interrupts disabled, the |
9695 | * and caller must save the original value of the current task (see | |
9696 | * curr_task() above) and restore that value before reenabling interrupts and | |
9697 | * re-starting the system. | |
9698 | * | |
9699 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
9700 | */ | |
36c8b586 | 9701 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
9702 | { |
9703 | cpu_curr(cpu) = p; | |
9704 | } | |
9705 | ||
9706 | #endif | |
29f59db3 | 9707 | |
bccbe08a PZ |
9708 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9709 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
9710 | { |
9711 | int i; | |
9712 | ||
9713 | for_each_possible_cpu(i) { | |
9714 | if (tg->cfs_rq) | |
9715 | kfree(tg->cfs_rq[i]); | |
9716 | if (tg->se) | |
9717 | kfree(tg->se[i]); | |
6f505b16 PZ |
9718 | } |
9719 | ||
9720 | kfree(tg->cfs_rq); | |
9721 | kfree(tg->se); | |
6f505b16 PZ |
9722 | } |
9723 | ||
ec7dc8ac DG |
9724 | static |
9725 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 9726 | { |
29f59db3 | 9727 | struct cfs_rq *cfs_rq; |
eab17229 | 9728 | struct sched_entity *se; |
9b5b7751 | 9729 | struct rq *rq; |
29f59db3 SV |
9730 | int i; |
9731 | ||
434d53b0 | 9732 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
9733 | if (!tg->cfs_rq) |
9734 | goto err; | |
434d53b0 | 9735 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
9736 | if (!tg->se) |
9737 | goto err; | |
052f1dc7 PZ |
9738 | |
9739 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
9740 | |
9741 | for_each_possible_cpu(i) { | |
9b5b7751 | 9742 | rq = cpu_rq(i); |
29f59db3 | 9743 | |
eab17229 LZ |
9744 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
9745 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
9746 | if (!cfs_rq) |
9747 | goto err; | |
9748 | ||
eab17229 LZ |
9749 | se = kzalloc_node(sizeof(struct sched_entity), |
9750 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
9751 | if (!se) |
9752 | goto err; | |
9753 | ||
eab17229 | 9754 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
9755 | } |
9756 | ||
9757 | return 1; | |
9758 | ||
9759 | err: | |
9760 | return 0; | |
9761 | } | |
9762 | ||
9763 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
9764 | { | |
9765 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
9766 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
9767 | } | |
9768 | ||
9769 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
9770 | { | |
9771 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
9772 | } | |
6d6bc0ad | 9773 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
9774 | static inline void free_fair_sched_group(struct task_group *tg) |
9775 | { | |
9776 | } | |
9777 | ||
ec7dc8ac DG |
9778 | static inline |
9779 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9780 | { |
9781 | return 1; | |
9782 | } | |
9783 | ||
9784 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
9785 | { | |
9786 | } | |
9787 | ||
9788 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
9789 | { | |
9790 | } | |
6d6bc0ad | 9791 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
9792 | |
9793 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
9794 | static void free_rt_sched_group(struct task_group *tg) |
9795 | { | |
9796 | int i; | |
9797 | ||
d0b27fa7 PZ |
9798 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
9799 | ||
bccbe08a PZ |
9800 | for_each_possible_cpu(i) { |
9801 | if (tg->rt_rq) | |
9802 | kfree(tg->rt_rq[i]); | |
9803 | if (tg->rt_se) | |
9804 | kfree(tg->rt_se[i]); | |
9805 | } | |
9806 | ||
9807 | kfree(tg->rt_rq); | |
9808 | kfree(tg->rt_se); | |
9809 | } | |
9810 | ||
ec7dc8ac DG |
9811 | static |
9812 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9813 | { |
9814 | struct rt_rq *rt_rq; | |
eab17229 | 9815 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
9816 | struct rq *rq; |
9817 | int i; | |
9818 | ||
434d53b0 | 9819 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
9820 | if (!tg->rt_rq) |
9821 | goto err; | |
434d53b0 | 9822 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
9823 | if (!tg->rt_se) |
9824 | goto err; | |
9825 | ||
d0b27fa7 PZ |
9826 | init_rt_bandwidth(&tg->rt_bandwidth, |
9827 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
9828 | |
9829 | for_each_possible_cpu(i) { | |
9830 | rq = cpu_rq(i); | |
9831 | ||
eab17229 LZ |
9832 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
9833 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
9834 | if (!rt_rq) |
9835 | goto err; | |
29f59db3 | 9836 | |
eab17229 LZ |
9837 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
9838 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
9839 | if (!rt_se) |
9840 | goto err; | |
29f59db3 | 9841 | |
eab17229 | 9842 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
9843 | } |
9844 | ||
bccbe08a PZ |
9845 | return 1; |
9846 | ||
9847 | err: | |
9848 | return 0; | |
9849 | } | |
9850 | ||
9851 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
9852 | { | |
9853 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
9854 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
9855 | } | |
9856 | ||
9857 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
9858 | { | |
9859 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
9860 | } | |
6d6bc0ad | 9861 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
9862 | static inline void free_rt_sched_group(struct task_group *tg) |
9863 | { | |
9864 | } | |
9865 | ||
ec7dc8ac DG |
9866 | static inline |
9867 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9868 | { |
9869 | return 1; | |
9870 | } | |
9871 | ||
9872 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
9873 | { | |
9874 | } | |
9875 | ||
9876 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
9877 | { | |
9878 | } | |
6d6bc0ad | 9879 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 9880 | |
d0b27fa7 | 9881 | #ifdef CONFIG_GROUP_SCHED |
bccbe08a PZ |
9882 | static void free_sched_group(struct task_group *tg) |
9883 | { | |
9884 | free_fair_sched_group(tg); | |
9885 | free_rt_sched_group(tg); | |
9886 | kfree(tg); | |
9887 | } | |
9888 | ||
9889 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 9890 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
9891 | { |
9892 | struct task_group *tg; | |
9893 | unsigned long flags; | |
9894 | int i; | |
9895 | ||
9896 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
9897 | if (!tg) | |
9898 | return ERR_PTR(-ENOMEM); | |
9899 | ||
ec7dc8ac | 9900 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
9901 | goto err; |
9902 | ||
ec7dc8ac | 9903 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
9904 | goto err; |
9905 | ||
8ed36996 | 9906 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 9907 | for_each_possible_cpu(i) { |
bccbe08a PZ |
9908 | register_fair_sched_group(tg, i); |
9909 | register_rt_sched_group(tg, i); | |
9b5b7751 | 9910 | } |
6f505b16 | 9911 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
9912 | |
9913 | WARN_ON(!parent); /* root should already exist */ | |
9914 | ||
9915 | tg->parent = parent; | |
f473aa5e | 9916 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 9917 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 9918 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 9919 | |
9b5b7751 | 9920 | return tg; |
29f59db3 SV |
9921 | |
9922 | err: | |
6f505b16 | 9923 | free_sched_group(tg); |
29f59db3 SV |
9924 | return ERR_PTR(-ENOMEM); |
9925 | } | |
9926 | ||
9b5b7751 | 9927 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 9928 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 9929 | { |
29f59db3 | 9930 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 9931 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
9932 | } |
9933 | ||
9b5b7751 | 9934 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 9935 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 9936 | { |
8ed36996 | 9937 | unsigned long flags; |
9b5b7751 | 9938 | int i; |
29f59db3 | 9939 | |
8ed36996 | 9940 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 9941 | for_each_possible_cpu(i) { |
bccbe08a PZ |
9942 | unregister_fair_sched_group(tg, i); |
9943 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 9944 | } |
6f505b16 | 9945 | list_del_rcu(&tg->list); |
f473aa5e | 9946 | list_del_rcu(&tg->siblings); |
8ed36996 | 9947 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 9948 | |
9b5b7751 | 9949 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 9950 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
9951 | } |
9952 | ||
9b5b7751 | 9953 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
9954 | * The caller of this function should have put the task in its new group |
9955 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
9956 | * reflect its new group. | |
9b5b7751 SV |
9957 | */ |
9958 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
9959 | { |
9960 | int on_rq, running; | |
9961 | unsigned long flags; | |
9962 | struct rq *rq; | |
9963 | ||
9964 | rq = task_rq_lock(tsk, &flags); | |
9965 | ||
29f59db3 SV |
9966 | update_rq_clock(rq); |
9967 | ||
051a1d1a | 9968 | running = task_current(rq, tsk); |
29f59db3 SV |
9969 | on_rq = tsk->se.on_rq; |
9970 | ||
0e1f3483 | 9971 | if (on_rq) |
29f59db3 | 9972 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
9973 | if (unlikely(running)) |
9974 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 9975 | |
6f505b16 | 9976 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 9977 | |
810b3817 PZ |
9978 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9979 | if (tsk->sched_class->moved_group) | |
9980 | tsk->sched_class->moved_group(tsk); | |
9981 | #endif | |
9982 | ||
0e1f3483 HS |
9983 | if (unlikely(running)) |
9984 | tsk->sched_class->set_curr_task(rq); | |
9985 | if (on_rq) | |
7074badb | 9986 | enqueue_task(rq, tsk, 0); |
29f59db3 | 9987 | |
29f59db3 SV |
9988 | task_rq_unlock(rq, &flags); |
9989 | } | |
6d6bc0ad | 9990 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 9991 | |
052f1dc7 | 9992 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 9993 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
9994 | { |
9995 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
9996 | int on_rq; |
9997 | ||
29f59db3 | 9998 | on_rq = se->on_rq; |
62fb1851 | 9999 | if (on_rq) |
29f59db3 SV |
10000 | dequeue_entity(cfs_rq, se, 0); |
10001 | ||
10002 | se->load.weight = shares; | |
e05510d0 | 10003 | se->load.inv_weight = 0; |
29f59db3 | 10004 | |
62fb1851 | 10005 | if (on_rq) |
29f59db3 | 10006 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 10007 | } |
62fb1851 | 10008 | |
c09595f6 PZ |
10009 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
10010 | { | |
10011 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
10012 | struct rq *rq = cfs_rq->rq; | |
10013 | unsigned long flags; | |
10014 | ||
10015 | spin_lock_irqsave(&rq->lock, flags); | |
10016 | __set_se_shares(se, shares); | |
10017 | spin_unlock_irqrestore(&rq->lock, flags); | |
29f59db3 SV |
10018 | } |
10019 | ||
8ed36996 PZ |
10020 | static DEFINE_MUTEX(shares_mutex); |
10021 | ||
4cf86d77 | 10022 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
10023 | { |
10024 | int i; | |
8ed36996 | 10025 | unsigned long flags; |
c61935fd | 10026 | |
ec7dc8ac DG |
10027 | /* |
10028 | * We can't change the weight of the root cgroup. | |
10029 | */ | |
10030 | if (!tg->se[0]) | |
10031 | return -EINVAL; | |
10032 | ||
18d95a28 PZ |
10033 | if (shares < MIN_SHARES) |
10034 | shares = MIN_SHARES; | |
cb4ad1ff MX |
10035 | else if (shares > MAX_SHARES) |
10036 | shares = MAX_SHARES; | |
62fb1851 | 10037 | |
8ed36996 | 10038 | mutex_lock(&shares_mutex); |
9b5b7751 | 10039 | if (tg->shares == shares) |
5cb350ba | 10040 | goto done; |
29f59db3 | 10041 | |
8ed36996 | 10042 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
10043 | for_each_possible_cpu(i) |
10044 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 10045 | list_del_rcu(&tg->siblings); |
8ed36996 | 10046 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
10047 | |
10048 | /* wait for any ongoing reference to this group to finish */ | |
10049 | synchronize_sched(); | |
10050 | ||
10051 | /* | |
10052 | * Now we are free to modify the group's share on each cpu | |
10053 | * w/o tripping rebalance_share or load_balance_fair. | |
10054 | */ | |
9b5b7751 | 10055 | tg->shares = shares; |
c09595f6 PZ |
10056 | for_each_possible_cpu(i) { |
10057 | /* | |
10058 | * force a rebalance | |
10059 | */ | |
10060 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 10061 | set_se_shares(tg->se[i], shares); |
c09595f6 | 10062 | } |
29f59db3 | 10063 | |
6b2d7700 SV |
10064 | /* |
10065 | * Enable load balance activity on this group, by inserting it back on | |
10066 | * each cpu's rq->leaf_cfs_rq_list. | |
10067 | */ | |
8ed36996 | 10068 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
10069 | for_each_possible_cpu(i) |
10070 | register_fair_sched_group(tg, i); | |
f473aa5e | 10071 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 10072 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 10073 | done: |
8ed36996 | 10074 | mutex_unlock(&shares_mutex); |
9b5b7751 | 10075 | return 0; |
29f59db3 SV |
10076 | } |
10077 | ||
5cb350ba DG |
10078 | unsigned long sched_group_shares(struct task_group *tg) |
10079 | { | |
10080 | return tg->shares; | |
10081 | } | |
052f1dc7 | 10082 | #endif |
5cb350ba | 10083 | |
052f1dc7 | 10084 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 10085 | /* |
9f0c1e56 | 10086 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 10087 | */ |
9f0c1e56 PZ |
10088 | static DEFINE_MUTEX(rt_constraints_mutex); |
10089 | ||
10090 | static unsigned long to_ratio(u64 period, u64 runtime) | |
10091 | { | |
10092 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 10093 | return 1ULL << 20; |
9f0c1e56 | 10094 | |
9a7e0b18 | 10095 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
10096 | } |
10097 | ||
9a7e0b18 PZ |
10098 | /* Must be called with tasklist_lock held */ |
10099 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 10100 | { |
9a7e0b18 | 10101 | struct task_struct *g, *p; |
b40b2e8e | 10102 | |
9a7e0b18 PZ |
10103 | do_each_thread(g, p) { |
10104 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
10105 | return 1; | |
10106 | } while_each_thread(g, p); | |
b40b2e8e | 10107 | |
9a7e0b18 PZ |
10108 | return 0; |
10109 | } | |
b40b2e8e | 10110 | |
9a7e0b18 PZ |
10111 | struct rt_schedulable_data { |
10112 | struct task_group *tg; | |
10113 | u64 rt_period; | |
10114 | u64 rt_runtime; | |
10115 | }; | |
b40b2e8e | 10116 | |
9a7e0b18 PZ |
10117 | static int tg_schedulable(struct task_group *tg, void *data) |
10118 | { | |
10119 | struct rt_schedulable_data *d = data; | |
10120 | struct task_group *child; | |
10121 | unsigned long total, sum = 0; | |
10122 | u64 period, runtime; | |
b40b2e8e | 10123 | |
9a7e0b18 PZ |
10124 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
10125 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 10126 | |
9a7e0b18 PZ |
10127 | if (tg == d->tg) { |
10128 | period = d->rt_period; | |
10129 | runtime = d->rt_runtime; | |
b40b2e8e | 10130 | } |
b40b2e8e | 10131 | |
98a4826b PZ |
10132 | #ifdef CONFIG_USER_SCHED |
10133 | if (tg == &root_task_group) { | |
10134 | period = global_rt_period(); | |
10135 | runtime = global_rt_runtime(); | |
10136 | } | |
10137 | #endif | |
10138 | ||
4653f803 PZ |
10139 | /* |
10140 | * Cannot have more runtime than the period. | |
10141 | */ | |
10142 | if (runtime > period && runtime != RUNTIME_INF) | |
10143 | return -EINVAL; | |
6f505b16 | 10144 | |
4653f803 PZ |
10145 | /* |
10146 | * Ensure we don't starve existing RT tasks. | |
10147 | */ | |
9a7e0b18 PZ |
10148 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
10149 | return -EBUSY; | |
6f505b16 | 10150 | |
9a7e0b18 | 10151 | total = to_ratio(period, runtime); |
6f505b16 | 10152 | |
4653f803 PZ |
10153 | /* |
10154 | * Nobody can have more than the global setting allows. | |
10155 | */ | |
10156 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
10157 | return -EINVAL; | |
6f505b16 | 10158 | |
4653f803 PZ |
10159 | /* |
10160 | * The sum of our children's runtime should not exceed our own. | |
10161 | */ | |
9a7e0b18 PZ |
10162 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
10163 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
10164 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 10165 | |
9a7e0b18 PZ |
10166 | if (child == d->tg) { |
10167 | period = d->rt_period; | |
10168 | runtime = d->rt_runtime; | |
10169 | } | |
6f505b16 | 10170 | |
9a7e0b18 | 10171 | sum += to_ratio(period, runtime); |
9f0c1e56 | 10172 | } |
6f505b16 | 10173 | |
9a7e0b18 PZ |
10174 | if (sum > total) |
10175 | return -EINVAL; | |
10176 | ||
10177 | return 0; | |
6f505b16 PZ |
10178 | } |
10179 | ||
9a7e0b18 | 10180 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 10181 | { |
9a7e0b18 PZ |
10182 | struct rt_schedulable_data data = { |
10183 | .tg = tg, | |
10184 | .rt_period = period, | |
10185 | .rt_runtime = runtime, | |
10186 | }; | |
10187 | ||
10188 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
10189 | } |
10190 | ||
d0b27fa7 PZ |
10191 | static int tg_set_bandwidth(struct task_group *tg, |
10192 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 10193 | { |
ac086bc2 | 10194 | int i, err = 0; |
9f0c1e56 | 10195 | |
9f0c1e56 | 10196 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 10197 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
10198 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
10199 | if (err) | |
9f0c1e56 | 10200 | goto unlock; |
ac086bc2 PZ |
10201 | |
10202 | spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
d0b27fa7 PZ |
10203 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
10204 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
10205 | |
10206 | for_each_possible_cpu(i) { | |
10207 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
10208 | ||
10209 | spin_lock(&rt_rq->rt_runtime_lock); | |
10210 | rt_rq->rt_runtime = rt_runtime; | |
10211 | spin_unlock(&rt_rq->rt_runtime_lock); | |
10212 | } | |
10213 | spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
9f0c1e56 | 10214 | unlock: |
521f1a24 | 10215 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
10216 | mutex_unlock(&rt_constraints_mutex); |
10217 | ||
10218 | return err; | |
6f505b16 PZ |
10219 | } |
10220 | ||
d0b27fa7 PZ |
10221 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
10222 | { | |
10223 | u64 rt_runtime, rt_period; | |
10224 | ||
10225 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
10226 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
10227 | if (rt_runtime_us < 0) | |
10228 | rt_runtime = RUNTIME_INF; | |
10229 | ||
10230 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
10231 | } | |
10232 | ||
9f0c1e56 PZ |
10233 | long sched_group_rt_runtime(struct task_group *tg) |
10234 | { | |
10235 | u64 rt_runtime_us; | |
10236 | ||
d0b27fa7 | 10237 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
10238 | return -1; |
10239 | ||
d0b27fa7 | 10240 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
10241 | do_div(rt_runtime_us, NSEC_PER_USEC); |
10242 | return rt_runtime_us; | |
10243 | } | |
d0b27fa7 PZ |
10244 | |
10245 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
10246 | { | |
10247 | u64 rt_runtime, rt_period; | |
10248 | ||
10249 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
10250 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
10251 | ||
619b0488 R |
10252 | if (rt_period == 0) |
10253 | return -EINVAL; | |
10254 | ||
d0b27fa7 PZ |
10255 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
10256 | } | |
10257 | ||
10258 | long sched_group_rt_period(struct task_group *tg) | |
10259 | { | |
10260 | u64 rt_period_us; | |
10261 | ||
10262 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
10263 | do_div(rt_period_us, NSEC_PER_USEC); | |
10264 | return rt_period_us; | |
10265 | } | |
10266 | ||
10267 | static int sched_rt_global_constraints(void) | |
10268 | { | |
4653f803 | 10269 | u64 runtime, period; |
d0b27fa7 PZ |
10270 | int ret = 0; |
10271 | ||
ec5d4989 HS |
10272 | if (sysctl_sched_rt_period <= 0) |
10273 | return -EINVAL; | |
10274 | ||
4653f803 PZ |
10275 | runtime = global_rt_runtime(); |
10276 | period = global_rt_period(); | |
10277 | ||
10278 | /* | |
10279 | * Sanity check on the sysctl variables. | |
10280 | */ | |
10281 | if (runtime > period && runtime != RUNTIME_INF) | |
10282 | return -EINVAL; | |
10b612f4 | 10283 | |
d0b27fa7 | 10284 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 10285 | read_lock(&tasklist_lock); |
4653f803 | 10286 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 10287 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
10288 | mutex_unlock(&rt_constraints_mutex); |
10289 | ||
10290 | return ret; | |
10291 | } | |
54e99124 DG |
10292 | |
10293 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
10294 | { | |
10295 | /* Don't accept realtime tasks when there is no way for them to run */ | |
10296 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
10297 | return 0; | |
10298 | ||
10299 | return 1; | |
10300 | } | |
10301 | ||
6d6bc0ad | 10302 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
10303 | static int sched_rt_global_constraints(void) |
10304 | { | |
ac086bc2 PZ |
10305 | unsigned long flags; |
10306 | int i; | |
10307 | ||
ec5d4989 HS |
10308 | if (sysctl_sched_rt_period <= 0) |
10309 | return -EINVAL; | |
10310 | ||
60aa605d PZ |
10311 | /* |
10312 | * There's always some RT tasks in the root group | |
10313 | * -- migration, kstopmachine etc.. | |
10314 | */ | |
10315 | if (sysctl_sched_rt_runtime == 0) | |
10316 | return -EBUSY; | |
10317 | ||
ac086bc2 PZ |
10318 | spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
10319 | for_each_possible_cpu(i) { | |
10320 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
10321 | ||
10322 | spin_lock(&rt_rq->rt_runtime_lock); | |
10323 | rt_rq->rt_runtime = global_rt_runtime(); | |
10324 | spin_unlock(&rt_rq->rt_runtime_lock); | |
10325 | } | |
10326 | spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); | |
10327 | ||
d0b27fa7 PZ |
10328 | return 0; |
10329 | } | |
6d6bc0ad | 10330 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
10331 | |
10332 | int sched_rt_handler(struct ctl_table *table, int write, | |
10333 | struct file *filp, void __user *buffer, size_t *lenp, | |
10334 | loff_t *ppos) | |
10335 | { | |
10336 | int ret; | |
10337 | int old_period, old_runtime; | |
10338 | static DEFINE_MUTEX(mutex); | |
10339 | ||
10340 | mutex_lock(&mutex); | |
10341 | old_period = sysctl_sched_rt_period; | |
10342 | old_runtime = sysctl_sched_rt_runtime; | |
10343 | ||
10344 | ret = proc_dointvec(table, write, filp, buffer, lenp, ppos); | |
10345 | ||
10346 | if (!ret && write) { | |
10347 | ret = sched_rt_global_constraints(); | |
10348 | if (ret) { | |
10349 | sysctl_sched_rt_period = old_period; | |
10350 | sysctl_sched_rt_runtime = old_runtime; | |
10351 | } else { | |
10352 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
10353 | def_rt_bandwidth.rt_period = | |
10354 | ns_to_ktime(global_rt_period()); | |
10355 | } | |
10356 | } | |
10357 | mutex_unlock(&mutex); | |
10358 | ||
10359 | return ret; | |
10360 | } | |
68318b8e | 10361 | |
052f1dc7 | 10362 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
10363 | |
10364 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 10365 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 10366 | { |
2b01dfe3 PM |
10367 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
10368 | struct task_group, css); | |
68318b8e SV |
10369 | } |
10370 | ||
10371 | static struct cgroup_subsys_state * | |
2b01dfe3 | 10372 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 10373 | { |
ec7dc8ac | 10374 | struct task_group *tg, *parent; |
68318b8e | 10375 | |
2b01dfe3 | 10376 | if (!cgrp->parent) { |
68318b8e | 10377 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
10378 | return &init_task_group.css; |
10379 | } | |
10380 | ||
ec7dc8ac DG |
10381 | parent = cgroup_tg(cgrp->parent); |
10382 | tg = sched_create_group(parent); | |
68318b8e SV |
10383 | if (IS_ERR(tg)) |
10384 | return ERR_PTR(-ENOMEM); | |
10385 | ||
68318b8e SV |
10386 | return &tg->css; |
10387 | } | |
10388 | ||
41a2d6cf IM |
10389 | static void |
10390 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 10391 | { |
2b01dfe3 | 10392 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
10393 | |
10394 | sched_destroy_group(tg); | |
10395 | } | |
10396 | ||
41a2d6cf IM |
10397 | static int |
10398 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
10399 | struct task_struct *tsk) | |
68318b8e | 10400 | { |
b68aa230 | 10401 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 10402 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
10403 | return -EINVAL; |
10404 | #else | |
68318b8e SV |
10405 | /* We don't support RT-tasks being in separate groups */ |
10406 | if (tsk->sched_class != &fair_sched_class) | |
10407 | return -EINVAL; | |
b68aa230 | 10408 | #endif |
68318b8e SV |
10409 | |
10410 | return 0; | |
10411 | } | |
10412 | ||
10413 | static void | |
2b01dfe3 | 10414 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
68318b8e SV |
10415 | struct cgroup *old_cont, struct task_struct *tsk) |
10416 | { | |
10417 | sched_move_task(tsk); | |
10418 | } | |
10419 | ||
052f1dc7 | 10420 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 10421 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 10422 | u64 shareval) |
68318b8e | 10423 | { |
2b01dfe3 | 10424 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
10425 | } |
10426 | ||
f4c753b7 | 10427 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 10428 | { |
2b01dfe3 | 10429 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
10430 | |
10431 | return (u64) tg->shares; | |
10432 | } | |
6d6bc0ad | 10433 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 10434 | |
052f1dc7 | 10435 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 10436 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 10437 | s64 val) |
6f505b16 | 10438 | { |
06ecb27c | 10439 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
10440 | } |
10441 | ||
06ecb27c | 10442 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 10443 | { |
06ecb27c | 10444 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 10445 | } |
d0b27fa7 PZ |
10446 | |
10447 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
10448 | u64 rt_period_us) | |
10449 | { | |
10450 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
10451 | } | |
10452 | ||
10453 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
10454 | { | |
10455 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
10456 | } | |
6d6bc0ad | 10457 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 10458 | |
fe5c7cc2 | 10459 | static struct cftype cpu_files[] = { |
052f1dc7 | 10460 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
10461 | { |
10462 | .name = "shares", | |
f4c753b7 PM |
10463 | .read_u64 = cpu_shares_read_u64, |
10464 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 10465 | }, |
052f1dc7 PZ |
10466 | #endif |
10467 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 10468 | { |
9f0c1e56 | 10469 | .name = "rt_runtime_us", |
06ecb27c PM |
10470 | .read_s64 = cpu_rt_runtime_read, |
10471 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 10472 | }, |
d0b27fa7 PZ |
10473 | { |
10474 | .name = "rt_period_us", | |
f4c753b7 PM |
10475 | .read_u64 = cpu_rt_period_read_uint, |
10476 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 10477 | }, |
052f1dc7 | 10478 | #endif |
68318b8e SV |
10479 | }; |
10480 | ||
10481 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
10482 | { | |
fe5c7cc2 | 10483 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
10484 | } |
10485 | ||
10486 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
10487 | .name = "cpu", |
10488 | .create = cpu_cgroup_create, | |
10489 | .destroy = cpu_cgroup_destroy, | |
10490 | .can_attach = cpu_cgroup_can_attach, | |
10491 | .attach = cpu_cgroup_attach, | |
10492 | .populate = cpu_cgroup_populate, | |
10493 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
10494 | .early_init = 1, |
10495 | }; | |
10496 | ||
052f1dc7 | 10497 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
10498 | |
10499 | #ifdef CONFIG_CGROUP_CPUACCT | |
10500 | ||
10501 | /* | |
10502 | * CPU accounting code for task groups. | |
10503 | * | |
10504 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
10505 | * (balbir@in.ibm.com). | |
10506 | */ | |
10507 | ||
934352f2 | 10508 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
10509 | struct cpuacct { |
10510 | struct cgroup_subsys_state css; | |
10511 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
10512 | u64 *cpuusage; | |
ef12fefa | 10513 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 10514 | struct cpuacct *parent; |
d842de87 SV |
10515 | }; |
10516 | ||
10517 | struct cgroup_subsys cpuacct_subsys; | |
10518 | ||
10519 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 10520 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 10521 | { |
32cd756a | 10522 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
10523 | struct cpuacct, css); |
10524 | } | |
10525 | ||
10526 | /* return cpu accounting group to which this task belongs */ | |
10527 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
10528 | { | |
10529 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
10530 | struct cpuacct, css); | |
10531 | } | |
10532 | ||
10533 | /* create a new cpu accounting group */ | |
10534 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 10535 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
10536 | { |
10537 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 10538 | int i; |
d842de87 SV |
10539 | |
10540 | if (!ca) | |
ef12fefa | 10541 | goto out; |
d842de87 SV |
10542 | |
10543 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
10544 | if (!ca->cpuusage) |
10545 | goto out_free_ca; | |
10546 | ||
10547 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
10548 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
10549 | goto out_free_counters; | |
d842de87 | 10550 | |
934352f2 BR |
10551 | if (cgrp->parent) |
10552 | ca->parent = cgroup_ca(cgrp->parent); | |
10553 | ||
d842de87 | 10554 | return &ca->css; |
ef12fefa BR |
10555 | |
10556 | out_free_counters: | |
10557 | while (--i >= 0) | |
10558 | percpu_counter_destroy(&ca->cpustat[i]); | |
10559 | free_percpu(ca->cpuusage); | |
10560 | out_free_ca: | |
10561 | kfree(ca); | |
10562 | out: | |
10563 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
10564 | } |
10565 | ||
10566 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 10567 | static void |
32cd756a | 10568 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 10569 | { |
32cd756a | 10570 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 10571 | int i; |
d842de87 | 10572 | |
ef12fefa BR |
10573 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
10574 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
10575 | free_percpu(ca->cpuusage); |
10576 | kfree(ca); | |
10577 | } | |
10578 | ||
720f5498 KC |
10579 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
10580 | { | |
b36128c8 | 10581 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
10582 | u64 data; |
10583 | ||
10584 | #ifndef CONFIG_64BIT | |
10585 | /* | |
10586 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
10587 | */ | |
10588 | spin_lock_irq(&cpu_rq(cpu)->lock); | |
10589 | data = *cpuusage; | |
10590 | spin_unlock_irq(&cpu_rq(cpu)->lock); | |
10591 | #else | |
10592 | data = *cpuusage; | |
10593 | #endif | |
10594 | ||
10595 | return data; | |
10596 | } | |
10597 | ||
10598 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
10599 | { | |
b36128c8 | 10600 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
10601 | |
10602 | #ifndef CONFIG_64BIT | |
10603 | /* | |
10604 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
10605 | */ | |
10606 | spin_lock_irq(&cpu_rq(cpu)->lock); | |
10607 | *cpuusage = val; | |
10608 | spin_unlock_irq(&cpu_rq(cpu)->lock); | |
10609 | #else | |
10610 | *cpuusage = val; | |
10611 | #endif | |
10612 | } | |
10613 | ||
d842de87 | 10614 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 10615 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 10616 | { |
32cd756a | 10617 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
10618 | u64 totalcpuusage = 0; |
10619 | int i; | |
10620 | ||
720f5498 KC |
10621 | for_each_present_cpu(i) |
10622 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
10623 | |
10624 | return totalcpuusage; | |
10625 | } | |
10626 | ||
0297b803 DG |
10627 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
10628 | u64 reset) | |
10629 | { | |
10630 | struct cpuacct *ca = cgroup_ca(cgrp); | |
10631 | int err = 0; | |
10632 | int i; | |
10633 | ||
10634 | if (reset) { | |
10635 | err = -EINVAL; | |
10636 | goto out; | |
10637 | } | |
10638 | ||
720f5498 KC |
10639 | for_each_present_cpu(i) |
10640 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 10641 | |
0297b803 DG |
10642 | out: |
10643 | return err; | |
10644 | } | |
10645 | ||
e9515c3c KC |
10646 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
10647 | struct seq_file *m) | |
10648 | { | |
10649 | struct cpuacct *ca = cgroup_ca(cgroup); | |
10650 | u64 percpu; | |
10651 | int i; | |
10652 | ||
10653 | for_each_present_cpu(i) { | |
10654 | percpu = cpuacct_cpuusage_read(ca, i); | |
10655 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
10656 | } | |
10657 | seq_printf(m, "\n"); | |
10658 | return 0; | |
10659 | } | |
10660 | ||
ef12fefa BR |
10661 | static const char *cpuacct_stat_desc[] = { |
10662 | [CPUACCT_STAT_USER] = "user", | |
10663 | [CPUACCT_STAT_SYSTEM] = "system", | |
10664 | }; | |
10665 | ||
10666 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
10667 | struct cgroup_map_cb *cb) | |
10668 | { | |
10669 | struct cpuacct *ca = cgroup_ca(cgrp); | |
10670 | int i; | |
10671 | ||
10672 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
10673 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
10674 | val = cputime64_to_clock_t(val); | |
10675 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
10676 | } | |
10677 | return 0; | |
10678 | } | |
10679 | ||
d842de87 SV |
10680 | static struct cftype files[] = { |
10681 | { | |
10682 | .name = "usage", | |
f4c753b7 PM |
10683 | .read_u64 = cpuusage_read, |
10684 | .write_u64 = cpuusage_write, | |
d842de87 | 10685 | }, |
e9515c3c KC |
10686 | { |
10687 | .name = "usage_percpu", | |
10688 | .read_seq_string = cpuacct_percpu_seq_read, | |
10689 | }, | |
ef12fefa BR |
10690 | { |
10691 | .name = "stat", | |
10692 | .read_map = cpuacct_stats_show, | |
10693 | }, | |
d842de87 SV |
10694 | }; |
10695 | ||
32cd756a | 10696 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 10697 | { |
32cd756a | 10698 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
10699 | } |
10700 | ||
10701 | /* | |
10702 | * charge this task's execution time to its accounting group. | |
10703 | * | |
10704 | * called with rq->lock held. | |
10705 | */ | |
10706 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
10707 | { | |
10708 | struct cpuacct *ca; | |
934352f2 | 10709 | int cpu; |
d842de87 | 10710 | |
c40c6f85 | 10711 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
10712 | return; |
10713 | ||
934352f2 | 10714 | cpu = task_cpu(tsk); |
a18b83b7 BR |
10715 | |
10716 | rcu_read_lock(); | |
10717 | ||
d842de87 | 10718 | ca = task_ca(tsk); |
d842de87 | 10719 | |
934352f2 | 10720 | for (; ca; ca = ca->parent) { |
b36128c8 | 10721 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
10722 | *cpuusage += cputime; |
10723 | } | |
a18b83b7 BR |
10724 | |
10725 | rcu_read_unlock(); | |
d842de87 SV |
10726 | } |
10727 | ||
ef12fefa BR |
10728 | /* |
10729 | * Charge the system/user time to the task's accounting group. | |
10730 | */ | |
10731 | static void cpuacct_update_stats(struct task_struct *tsk, | |
10732 | enum cpuacct_stat_index idx, cputime_t val) | |
10733 | { | |
10734 | struct cpuacct *ca; | |
10735 | ||
10736 | if (unlikely(!cpuacct_subsys.active)) | |
10737 | return; | |
10738 | ||
10739 | rcu_read_lock(); | |
10740 | ca = task_ca(tsk); | |
10741 | ||
10742 | do { | |
10743 | percpu_counter_add(&ca->cpustat[idx], val); | |
10744 | ca = ca->parent; | |
10745 | } while (ca); | |
10746 | rcu_read_unlock(); | |
10747 | } | |
10748 | ||
d842de87 SV |
10749 | struct cgroup_subsys cpuacct_subsys = { |
10750 | .name = "cpuacct", | |
10751 | .create = cpuacct_create, | |
10752 | .destroy = cpuacct_destroy, | |
10753 | .populate = cpuacct_populate, | |
10754 | .subsys_id = cpuacct_subsys_id, | |
10755 | }; | |
10756 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
10757 | |
10758 | #ifndef CONFIG_SMP | |
10759 | ||
10760 | int rcu_expedited_torture_stats(char *page) | |
10761 | { | |
10762 | return 0; | |
10763 | } | |
10764 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
10765 | ||
10766 | void synchronize_sched_expedited(void) | |
10767 | { | |
10768 | } | |
10769 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
10770 | ||
10771 | #else /* #ifndef CONFIG_SMP */ | |
10772 | ||
10773 | static DEFINE_PER_CPU(struct migration_req, rcu_migration_req); | |
10774 | static DEFINE_MUTEX(rcu_sched_expedited_mutex); | |
10775 | ||
10776 | #define RCU_EXPEDITED_STATE_POST -2 | |
10777 | #define RCU_EXPEDITED_STATE_IDLE -1 | |
10778 | ||
10779 | static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
10780 | ||
10781 | int rcu_expedited_torture_stats(char *page) | |
10782 | { | |
10783 | int cnt = 0; | |
10784 | int cpu; | |
10785 | ||
10786 | cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state); | |
10787 | for_each_online_cpu(cpu) { | |
10788 | cnt += sprintf(&page[cnt], " %d:%d", | |
10789 | cpu, per_cpu(rcu_migration_req, cpu).dest_cpu); | |
10790 | } | |
10791 | cnt += sprintf(&page[cnt], "\n"); | |
10792 | return cnt; | |
10793 | } | |
10794 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
10795 | ||
10796 | static long synchronize_sched_expedited_count; | |
10797 | ||
10798 | /* | |
10799 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
10800 | * approach to force grace period to end quickly. This consumes | |
10801 | * significant time on all CPUs, and is thus not recommended for | |
10802 | * any sort of common-case code. | |
10803 | * | |
10804 | * Note that it is illegal to call this function while holding any | |
10805 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
10806 | * observe this restriction will result in deadlock. | |
10807 | */ | |
10808 | void synchronize_sched_expedited(void) | |
10809 | { | |
10810 | int cpu; | |
10811 | unsigned long flags; | |
10812 | bool need_full_sync = 0; | |
10813 | struct rq *rq; | |
10814 | struct migration_req *req; | |
10815 | long snap; | |
10816 | int trycount = 0; | |
10817 | ||
10818 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
10819 | snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1; | |
10820 | get_online_cpus(); | |
10821 | while (!mutex_trylock(&rcu_sched_expedited_mutex)) { | |
10822 | put_online_cpus(); | |
10823 | if (trycount++ < 10) | |
10824 | udelay(trycount * num_online_cpus()); | |
10825 | else { | |
10826 | synchronize_sched(); | |
10827 | return; | |
10828 | } | |
10829 | if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) { | |
10830 | smp_mb(); /* ensure test happens before caller kfree */ | |
10831 | return; | |
10832 | } | |
10833 | get_online_cpus(); | |
10834 | } | |
10835 | rcu_expedited_state = RCU_EXPEDITED_STATE_POST; | |
10836 | for_each_online_cpu(cpu) { | |
10837 | rq = cpu_rq(cpu); | |
10838 | req = &per_cpu(rcu_migration_req, cpu); | |
10839 | init_completion(&req->done); | |
10840 | req->task = NULL; | |
10841 | req->dest_cpu = RCU_MIGRATION_NEED_QS; | |
10842 | spin_lock_irqsave(&rq->lock, flags); | |
10843 | list_add(&req->list, &rq->migration_queue); | |
10844 | spin_unlock_irqrestore(&rq->lock, flags); | |
10845 | wake_up_process(rq->migration_thread); | |
10846 | } | |
10847 | for_each_online_cpu(cpu) { | |
10848 | rcu_expedited_state = cpu; | |
10849 | req = &per_cpu(rcu_migration_req, cpu); | |
10850 | rq = cpu_rq(cpu); | |
10851 | wait_for_completion(&req->done); | |
10852 | spin_lock_irqsave(&rq->lock, flags); | |
10853 | if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC)) | |
10854 | need_full_sync = 1; | |
10855 | req->dest_cpu = RCU_MIGRATION_IDLE; | |
10856 | spin_unlock_irqrestore(&rq->lock, flags); | |
10857 | } | |
10858 | rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
10859 | mutex_unlock(&rcu_sched_expedited_mutex); | |
10860 | put_online_cpus(); | |
10861 | if (need_full_sync) | |
10862 | synchronize_sched(); | |
10863 | } | |
10864 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
10865 | ||
10866 | #endif /* #else #ifndef CONFIG_SMP */ |