]>
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> |
cdd6c482 | 42 | #include <linux/perf_event.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 | 143 | /* nests inside the rq lock: */ |
0986b11b | 144 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
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 | ||
0986b11b | 181 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 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 | ||
0986b11b | 203 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 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 | 219 | } |
0986b11b | 220 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
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 | ||
7c941438 | 236 | #ifdef CONFIG_CGROUP_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 { |
68318b8e | 246 | struct cgroup_subsys_state css; |
6c415b92 | 247 | |
052f1dc7 | 248 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
249 | /* schedulable entities of this group on each cpu */ |
250 | struct sched_entity **se; | |
251 | /* runqueue "owned" by this group on each cpu */ | |
252 | struct cfs_rq **cfs_rq; | |
253 | unsigned long shares; | |
052f1dc7 PZ |
254 | #endif |
255 | ||
256 | #ifdef CONFIG_RT_GROUP_SCHED | |
257 | struct sched_rt_entity **rt_se; | |
258 | struct rt_rq **rt_rq; | |
259 | ||
d0b27fa7 | 260 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 261 | #endif |
6b2d7700 | 262 | |
ae8393e5 | 263 | struct rcu_head rcu; |
6f505b16 | 264 | struct list_head list; |
f473aa5e PZ |
265 | |
266 | struct task_group *parent; | |
267 | struct list_head siblings; | |
268 | struct list_head children; | |
29f59db3 SV |
269 | }; |
270 | ||
eff766a6 | 271 | #define root_task_group init_task_group |
6f505b16 | 272 | |
8ed36996 | 273 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
274 | * a task group's cpu shares. |
275 | */ | |
8ed36996 | 276 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 277 | |
e9036b36 CG |
278 | #ifdef CONFIG_FAIR_GROUP_SCHED |
279 | ||
57310a98 PZ |
280 | #ifdef CONFIG_SMP |
281 | static int root_task_group_empty(void) | |
282 | { | |
283 | return list_empty(&root_task_group.children); | |
284 | } | |
285 | #endif | |
286 | ||
052f1dc7 | 287 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 288 | |
cb4ad1ff | 289 | /* |
2e084786 LJ |
290 | * A weight of 0 or 1 can cause arithmetics problems. |
291 | * A weight of a cfs_rq is the sum of weights of which entities | |
292 | * are queued on this cfs_rq, so a weight of a entity should not be | |
293 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
294 | * (The default weight is 1024 - so there's no practical |
295 | * limitation from this.) | |
296 | */ | |
18d95a28 | 297 | #define MIN_SHARES 2 |
2e084786 | 298 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 299 | |
052f1dc7 PZ |
300 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
301 | #endif | |
302 | ||
29f59db3 | 303 | /* Default task group. |
3a252015 | 304 | * Every task in system belong to this group at bootup. |
29f59db3 | 305 | */ |
434d53b0 | 306 | struct task_group init_task_group; |
29f59db3 SV |
307 | |
308 | /* return group to which a task belongs */ | |
4cf86d77 | 309 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 310 | { |
4cf86d77 | 311 | struct task_group *tg; |
9b5b7751 | 312 | |
7c941438 | 313 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
314 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
315 | struct task_group, css); | |
24e377a8 | 316 | #else |
41a2d6cf | 317 | tg = &init_task_group; |
24e377a8 | 318 | #endif |
9b5b7751 | 319 | return tg; |
29f59db3 SV |
320 | } |
321 | ||
322 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 323 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 324 | { |
052f1dc7 | 325 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
326 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
327 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 328 | #endif |
6f505b16 | 329 | |
052f1dc7 | 330 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
331 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
332 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 333 | #endif |
29f59db3 SV |
334 | } |
335 | ||
336 | #else | |
337 | ||
6f505b16 | 338 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
339 | static inline struct task_group *task_group(struct task_struct *p) |
340 | { | |
341 | return NULL; | |
342 | } | |
29f59db3 | 343 | |
7c941438 | 344 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 345 | |
6aa645ea IM |
346 | /* CFS-related fields in a runqueue */ |
347 | struct cfs_rq { | |
348 | struct load_weight load; | |
349 | unsigned long nr_running; | |
350 | ||
6aa645ea | 351 | u64 exec_clock; |
e9acbff6 | 352 | u64 min_vruntime; |
6aa645ea IM |
353 | |
354 | struct rb_root tasks_timeline; | |
355 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
356 | |
357 | struct list_head tasks; | |
358 | struct list_head *balance_iterator; | |
359 | ||
360 | /* | |
361 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
362 | * It is set to NULL otherwise (i.e when none are currently running). |
363 | */ | |
4793241b | 364 | struct sched_entity *curr, *next, *last; |
ddc97297 | 365 | |
5ac5c4d6 | 366 | unsigned int nr_spread_over; |
ddc97297 | 367 | |
62160e3f | 368 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
369 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
370 | ||
41a2d6cf IM |
371 | /* |
372 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
373 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
374 | * (like users, containers etc.) | |
375 | * | |
376 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
377 | * list is used during load balance. | |
378 | */ | |
41a2d6cf IM |
379 | struct list_head leaf_cfs_rq_list; |
380 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
381 | |
382 | #ifdef CONFIG_SMP | |
c09595f6 | 383 | /* |
c8cba857 | 384 | * the part of load.weight contributed by tasks |
c09595f6 | 385 | */ |
c8cba857 | 386 | unsigned long task_weight; |
c09595f6 | 387 | |
c8cba857 PZ |
388 | /* |
389 | * h_load = weight * f(tg) | |
390 | * | |
391 | * Where f(tg) is the recursive weight fraction assigned to | |
392 | * this group. | |
393 | */ | |
394 | unsigned long h_load; | |
c09595f6 | 395 | |
c8cba857 PZ |
396 | /* |
397 | * this cpu's part of tg->shares | |
398 | */ | |
399 | unsigned long shares; | |
f1d239f7 PZ |
400 | |
401 | /* | |
402 | * load.weight at the time we set shares | |
403 | */ | |
404 | unsigned long rq_weight; | |
c09595f6 | 405 | #endif |
6aa645ea IM |
406 | #endif |
407 | }; | |
1da177e4 | 408 | |
6aa645ea IM |
409 | /* Real-Time classes' related field in a runqueue: */ |
410 | struct rt_rq { | |
411 | struct rt_prio_array active; | |
63489e45 | 412 | unsigned long rt_nr_running; |
052f1dc7 | 413 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
414 | struct { |
415 | int curr; /* highest queued rt task prio */ | |
398a153b | 416 | #ifdef CONFIG_SMP |
e864c499 | 417 | int next; /* next highest */ |
398a153b | 418 | #endif |
e864c499 | 419 | } highest_prio; |
6f505b16 | 420 | #endif |
fa85ae24 | 421 | #ifdef CONFIG_SMP |
73fe6aae | 422 | unsigned long rt_nr_migratory; |
a1ba4d8b | 423 | unsigned long rt_nr_total; |
a22d7fc1 | 424 | int overloaded; |
917b627d | 425 | struct plist_head pushable_tasks; |
fa85ae24 | 426 | #endif |
6f505b16 | 427 | int rt_throttled; |
fa85ae24 | 428 | u64 rt_time; |
ac086bc2 | 429 | u64 rt_runtime; |
ea736ed5 | 430 | /* Nests inside the rq lock: */ |
0986b11b | 431 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 432 | |
052f1dc7 | 433 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
434 | unsigned long rt_nr_boosted; |
435 | ||
6f505b16 PZ |
436 | struct rq *rq; |
437 | struct list_head leaf_rt_rq_list; | |
438 | struct task_group *tg; | |
6f505b16 | 439 | #endif |
6aa645ea IM |
440 | }; |
441 | ||
57d885fe GH |
442 | #ifdef CONFIG_SMP |
443 | ||
444 | /* | |
445 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
446 | * variables. Each exclusive cpuset essentially defines an island domain by |
447 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
448 | * exclusive cpuset is created, we also create and attach a new root-domain |
449 | * object. | |
450 | * | |
57d885fe GH |
451 | */ |
452 | struct root_domain { | |
453 | atomic_t refcount; | |
c6c4927b RR |
454 | cpumask_var_t span; |
455 | cpumask_var_t online; | |
637f5085 | 456 | |
0eab9146 | 457 | /* |
637f5085 GH |
458 | * The "RT overload" flag: it gets set if a CPU has more than |
459 | * one runnable RT task. | |
460 | */ | |
c6c4927b | 461 | cpumask_var_t rto_mask; |
0eab9146 | 462 | atomic_t rto_count; |
6e0534f2 GH |
463 | #ifdef CONFIG_SMP |
464 | struct cpupri cpupri; | |
465 | #endif | |
57d885fe GH |
466 | }; |
467 | ||
dc938520 GH |
468 | /* |
469 | * By default the system creates a single root-domain with all cpus as | |
470 | * members (mimicking the global state we have today). | |
471 | */ | |
57d885fe GH |
472 | static struct root_domain def_root_domain; |
473 | ||
474 | #endif | |
475 | ||
1da177e4 LT |
476 | /* |
477 | * This is the main, per-CPU runqueue data structure. | |
478 | * | |
479 | * Locking rule: those places that want to lock multiple runqueues | |
480 | * (such as the load balancing or the thread migration code), lock | |
481 | * acquire operations must be ordered by ascending &runqueue. | |
482 | */ | |
70b97a7f | 483 | struct rq { |
d8016491 | 484 | /* runqueue lock: */ |
05fa785c | 485 | raw_spinlock_t lock; |
1da177e4 LT |
486 | |
487 | /* | |
488 | * nr_running and cpu_load should be in the same cacheline because | |
489 | * remote CPUs use both these fields when doing load calculation. | |
490 | */ | |
491 | unsigned long nr_running; | |
6aa645ea IM |
492 | #define CPU_LOAD_IDX_MAX 5 |
493 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
46cb4b7c | 494 | #ifdef CONFIG_NO_HZ |
39c0cbe2 | 495 | u64 nohz_stamp; |
46cb4b7c SS |
496 | unsigned char in_nohz_recently; |
497 | #endif | |
a64692a3 MG |
498 | unsigned int skip_clock_update; |
499 | ||
d8016491 IM |
500 | /* capture load from *all* tasks on this cpu: */ |
501 | struct load_weight load; | |
6aa645ea IM |
502 | unsigned long nr_load_updates; |
503 | u64 nr_switches; | |
504 | ||
505 | struct cfs_rq cfs; | |
6f505b16 | 506 | struct rt_rq rt; |
6f505b16 | 507 | |
6aa645ea | 508 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
509 | /* list of leaf cfs_rq on this cpu: */ |
510 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
511 | #endif |
512 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 513 | struct list_head leaf_rt_rq_list; |
1da177e4 | 514 | #endif |
1da177e4 LT |
515 | |
516 | /* | |
517 | * This is part of a global counter where only the total sum | |
518 | * over all CPUs matters. A task can increase this counter on | |
519 | * one CPU and if it got migrated afterwards it may decrease | |
520 | * it on another CPU. Always updated under the runqueue lock: | |
521 | */ | |
522 | unsigned long nr_uninterruptible; | |
523 | ||
36c8b586 | 524 | struct task_struct *curr, *idle; |
c9819f45 | 525 | unsigned long next_balance; |
1da177e4 | 526 | struct mm_struct *prev_mm; |
6aa645ea | 527 | |
3e51f33f | 528 | u64 clock; |
6aa645ea | 529 | |
1da177e4 LT |
530 | atomic_t nr_iowait; |
531 | ||
532 | #ifdef CONFIG_SMP | |
0eab9146 | 533 | struct root_domain *rd; |
1da177e4 LT |
534 | struct sched_domain *sd; |
535 | ||
a0a522ce | 536 | unsigned char idle_at_tick; |
1da177e4 | 537 | /* For active balancing */ |
3f029d3c | 538 | int post_schedule; |
1da177e4 LT |
539 | int active_balance; |
540 | int push_cpu; | |
d8016491 IM |
541 | /* cpu of this runqueue: */ |
542 | int cpu; | |
1f11eb6a | 543 | int online; |
1da177e4 | 544 | |
a8a51d5e | 545 | unsigned long avg_load_per_task; |
1da177e4 | 546 | |
36c8b586 | 547 | struct task_struct *migration_thread; |
1da177e4 | 548 | struct list_head migration_queue; |
e9e9250b PZ |
549 | |
550 | u64 rt_avg; | |
551 | u64 age_stamp; | |
1b9508f6 MG |
552 | u64 idle_stamp; |
553 | u64 avg_idle; | |
1da177e4 LT |
554 | #endif |
555 | ||
dce48a84 TG |
556 | /* calc_load related fields */ |
557 | unsigned long calc_load_update; | |
558 | long calc_load_active; | |
559 | ||
8f4d37ec | 560 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
561 | #ifdef CONFIG_SMP |
562 | int hrtick_csd_pending; | |
563 | struct call_single_data hrtick_csd; | |
564 | #endif | |
8f4d37ec PZ |
565 | struct hrtimer hrtick_timer; |
566 | #endif | |
567 | ||
1da177e4 LT |
568 | #ifdef CONFIG_SCHEDSTATS |
569 | /* latency stats */ | |
570 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
571 | unsigned long long rq_cpu_time; |
572 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
573 | |
574 | /* sys_sched_yield() stats */ | |
480b9434 | 575 | unsigned int yld_count; |
1da177e4 LT |
576 | |
577 | /* schedule() stats */ | |
480b9434 KC |
578 | unsigned int sched_switch; |
579 | unsigned int sched_count; | |
580 | unsigned int sched_goidle; | |
1da177e4 LT |
581 | |
582 | /* try_to_wake_up() stats */ | |
480b9434 KC |
583 | unsigned int ttwu_count; |
584 | unsigned int ttwu_local; | |
b8efb561 IM |
585 | |
586 | /* BKL stats */ | |
480b9434 | 587 | unsigned int bkl_count; |
1da177e4 LT |
588 | #endif |
589 | }; | |
590 | ||
f34e3b61 | 591 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 592 | |
7d478721 PZ |
593 | static inline |
594 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) | |
dd41f596 | 595 | { |
7d478721 | 596 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); |
a64692a3 MG |
597 | |
598 | /* | |
599 | * A queue event has occurred, and we're going to schedule. In | |
600 | * this case, we can save a useless back to back clock update. | |
601 | */ | |
602 | if (test_tsk_need_resched(p)) | |
603 | rq->skip_clock_update = 1; | |
dd41f596 IM |
604 | } |
605 | ||
0a2966b4 CL |
606 | static inline int cpu_of(struct rq *rq) |
607 | { | |
608 | #ifdef CONFIG_SMP | |
609 | return rq->cpu; | |
610 | #else | |
611 | return 0; | |
612 | #endif | |
613 | } | |
614 | ||
497f0ab3 | 615 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d PM |
616 | rcu_dereference_check((p), \ |
617 | rcu_read_lock_sched_held() || \ | |
618 | lockdep_is_held(&sched_domains_mutex)) | |
619 | ||
674311d5 NP |
620 | /* |
621 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 622 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
623 | * |
624 | * The domain tree of any CPU may only be accessed from within | |
625 | * preempt-disabled sections. | |
626 | */ | |
48f24c4d | 627 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 628 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
629 | |
630 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
631 | #define this_rq() (&__get_cpu_var(runqueues)) | |
632 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
633 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 634 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 635 | |
aa9c4c0f | 636 | inline void update_rq_clock(struct rq *rq) |
3e51f33f | 637 | { |
a64692a3 MG |
638 | if (!rq->skip_clock_update) |
639 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
3e51f33f PZ |
640 | } |
641 | ||
bf5c91ba IM |
642 | /* |
643 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
644 | */ | |
645 | #ifdef CONFIG_SCHED_DEBUG | |
646 | # define const_debug __read_mostly | |
647 | #else | |
648 | # define const_debug static const | |
649 | #endif | |
650 | ||
017730c1 IM |
651 | /** |
652 | * runqueue_is_locked | |
e17b38bf | 653 | * @cpu: the processor in question. |
017730c1 IM |
654 | * |
655 | * Returns true if the current cpu runqueue is locked. | |
656 | * This interface allows printk to be called with the runqueue lock | |
657 | * held and know whether or not it is OK to wake up the klogd. | |
658 | */ | |
89f19f04 | 659 | int runqueue_is_locked(int cpu) |
017730c1 | 660 | { |
05fa785c | 661 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
662 | } |
663 | ||
bf5c91ba IM |
664 | /* |
665 | * Debugging: various feature bits | |
666 | */ | |
f00b45c1 PZ |
667 | |
668 | #define SCHED_FEAT(name, enabled) \ | |
669 | __SCHED_FEAT_##name , | |
670 | ||
bf5c91ba | 671 | enum { |
f00b45c1 | 672 | #include "sched_features.h" |
bf5c91ba IM |
673 | }; |
674 | ||
f00b45c1 PZ |
675 | #undef SCHED_FEAT |
676 | ||
677 | #define SCHED_FEAT(name, enabled) \ | |
678 | (1UL << __SCHED_FEAT_##name) * enabled | | |
679 | ||
bf5c91ba | 680 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
681 | #include "sched_features.h" |
682 | 0; | |
683 | ||
684 | #undef SCHED_FEAT | |
685 | ||
686 | #ifdef CONFIG_SCHED_DEBUG | |
687 | #define SCHED_FEAT(name, enabled) \ | |
688 | #name , | |
689 | ||
983ed7a6 | 690 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
691 | #include "sched_features.h" |
692 | NULL | |
693 | }; | |
694 | ||
695 | #undef SCHED_FEAT | |
696 | ||
34f3a814 | 697 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 698 | { |
f00b45c1 PZ |
699 | int i; |
700 | ||
701 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
702 | if (!(sysctl_sched_features & (1UL << i))) |
703 | seq_puts(m, "NO_"); | |
704 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 705 | } |
34f3a814 | 706 | seq_puts(m, "\n"); |
f00b45c1 | 707 | |
34f3a814 | 708 | return 0; |
f00b45c1 PZ |
709 | } |
710 | ||
711 | static ssize_t | |
712 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
713 | size_t cnt, loff_t *ppos) | |
714 | { | |
715 | char buf[64]; | |
716 | char *cmp = buf; | |
717 | int neg = 0; | |
718 | int i; | |
719 | ||
720 | if (cnt > 63) | |
721 | cnt = 63; | |
722 | ||
723 | if (copy_from_user(&buf, ubuf, cnt)) | |
724 | return -EFAULT; | |
725 | ||
726 | buf[cnt] = 0; | |
727 | ||
c24b7c52 | 728 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
729 | neg = 1; |
730 | cmp += 3; | |
731 | } | |
732 | ||
733 | for (i = 0; sched_feat_names[i]; i++) { | |
734 | int len = strlen(sched_feat_names[i]); | |
735 | ||
736 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
737 | if (neg) | |
738 | sysctl_sched_features &= ~(1UL << i); | |
739 | else | |
740 | sysctl_sched_features |= (1UL << i); | |
741 | break; | |
742 | } | |
743 | } | |
744 | ||
745 | if (!sched_feat_names[i]) | |
746 | return -EINVAL; | |
747 | ||
42994724 | 748 | *ppos += cnt; |
f00b45c1 PZ |
749 | |
750 | return cnt; | |
751 | } | |
752 | ||
34f3a814 LZ |
753 | static int sched_feat_open(struct inode *inode, struct file *filp) |
754 | { | |
755 | return single_open(filp, sched_feat_show, NULL); | |
756 | } | |
757 | ||
828c0950 | 758 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
759 | .open = sched_feat_open, |
760 | .write = sched_feat_write, | |
761 | .read = seq_read, | |
762 | .llseek = seq_lseek, | |
763 | .release = single_release, | |
f00b45c1 PZ |
764 | }; |
765 | ||
766 | static __init int sched_init_debug(void) | |
767 | { | |
f00b45c1 PZ |
768 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
769 | &sched_feat_fops); | |
770 | ||
771 | return 0; | |
772 | } | |
773 | late_initcall(sched_init_debug); | |
774 | ||
775 | #endif | |
776 | ||
777 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 778 | |
b82d9fdd PZ |
779 | /* |
780 | * Number of tasks to iterate in a single balance run. | |
781 | * Limited because this is done with IRQs disabled. | |
782 | */ | |
783 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
784 | ||
2398f2c6 PZ |
785 | /* |
786 | * ratelimit for updating the group shares. | |
55cd5340 | 787 | * default: 0.25ms |
2398f2c6 | 788 | */ |
55cd5340 | 789 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
0bcdcf28 | 790 | unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 791 | |
ffda12a1 PZ |
792 | /* |
793 | * Inject some fuzzyness into changing the per-cpu group shares | |
794 | * this avoids remote rq-locks at the expense of fairness. | |
795 | * default: 4 | |
796 | */ | |
797 | unsigned int sysctl_sched_shares_thresh = 4; | |
798 | ||
e9e9250b PZ |
799 | /* |
800 | * period over which we average the RT time consumption, measured | |
801 | * in ms. | |
802 | * | |
803 | * default: 1s | |
804 | */ | |
805 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
806 | ||
fa85ae24 | 807 | /* |
9f0c1e56 | 808 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
809 | * default: 1s |
810 | */ | |
9f0c1e56 | 811 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 812 | |
6892b75e IM |
813 | static __read_mostly int scheduler_running; |
814 | ||
9f0c1e56 PZ |
815 | /* |
816 | * part of the period that we allow rt tasks to run in us. | |
817 | * default: 0.95s | |
818 | */ | |
819 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 820 | |
d0b27fa7 PZ |
821 | static inline u64 global_rt_period(void) |
822 | { | |
823 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
824 | } | |
825 | ||
826 | static inline u64 global_rt_runtime(void) | |
827 | { | |
e26873bb | 828 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
829 | return RUNTIME_INF; |
830 | ||
831 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
832 | } | |
fa85ae24 | 833 | |
1da177e4 | 834 | #ifndef prepare_arch_switch |
4866cde0 NP |
835 | # define prepare_arch_switch(next) do { } while (0) |
836 | #endif | |
837 | #ifndef finish_arch_switch | |
838 | # define finish_arch_switch(prev) do { } while (0) | |
839 | #endif | |
840 | ||
051a1d1a DA |
841 | static inline int task_current(struct rq *rq, struct task_struct *p) |
842 | { | |
843 | return rq->curr == p; | |
844 | } | |
845 | ||
4866cde0 | 846 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 847 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 848 | { |
051a1d1a | 849 | return task_current(rq, p); |
4866cde0 NP |
850 | } |
851 | ||
70b97a7f | 852 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
853 | { |
854 | } | |
855 | ||
70b97a7f | 856 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 857 | { |
da04c035 IM |
858 | #ifdef CONFIG_DEBUG_SPINLOCK |
859 | /* this is a valid case when another task releases the spinlock */ | |
860 | rq->lock.owner = current; | |
861 | #endif | |
8a25d5de IM |
862 | /* |
863 | * If we are tracking spinlock dependencies then we have to | |
864 | * fix up the runqueue lock - which gets 'carried over' from | |
865 | * prev into current: | |
866 | */ | |
867 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
868 | ||
05fa785c | 869 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
870 | } |
871 | ||
872 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 873 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
874 | { |
875 | #ifdef CONFIG_SMP | |
876 | return p->oncpu; | |
877 | #else | |
051a1d1a | 878 | return task_current(rq, p); |
4866cde0 NP |
879 | #endif |
880 | } | |
881 | ||
70b97a7f | 882 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
883 | { |
884 | #ifdef CONFIG_SMP | |
885 | /* | |
886 | * We can optimise this out completely for !SMP, because the | |
887 | * SMP rebalancing from interrupt is the only thing that cares | |
888 | * here. | |
889 | */ | |
890 | next->oncpu = 1; | |
891 | #endif | |
892 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 893 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 894 | #else |
05fa785c | 895 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
896 | #endif |
897 | } | |
898 | ||
70b97a7f | 899 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
900 | { |
901 | #ifdef CONFIG_SMP | |
902 | /* | |
903 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
904 | * We must ensure this doesn't happen until the switch is completely | |
905 | * finished. | |
906 | */ | |
907 | smp_wmb(); | |
908 | prev->oncpu = 0; | |
909 | #endif | |
910 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
911 | local_irq_enable(); | |
1da177e4 | 912 | #endif |
4866cde0 NP |
913 | } |
914 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 915 | |
0970d299 | 916 | /* |
65cc8e48 PZ |
917 | * Check whether the task is waking, we use this to synchronize ->cpus_allowed |
918 | * against ttwu(). | |
0970d299 PZ |
919 | */ |
920 | static inline int task_is_waking(struct task_struct *p) | |
921 | { | |
0017d735 | 922 | return unlikely(p->state == TASK_WAKING); |
0970d299 PZ |
923 | } |
924 | ||
b29739f9 IM |
925 | /* |
926 | * __task_rq_lock - lock the runqueue a given task resides on. | |
927 | * Must be called interrupts disabled. | |
928 | */ | |
70b97a7f | 929 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
930 | __acquires(rq->lock) |
931 | { | |
0970d299 PZ |
932 | struct rq *rq; |
933 | ||
3a5c359a | 934 | for (;;) { |
0970d299 | 935 | rq = task_rq(p); |
05fa785c | 936 | raw_spin_lock(&rq->lock); |
65cc8e48 | 937 | if (likely(rq == task_rq(p))) |
3a5c359a | 938 | return rq; |
05fa785c | 939 | raw_spin_unlock(&rq->lock); |
b29739f9 | 940 | } |
b29739f9 IM |
941 | } |
942 | ||
1da177e4 LT |
943 | /* |
944 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 945 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
946 | * explicitly disabling preemption. |
947 | */ | |
70b97a7f | 948 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
949 | __acquires(rq->lock) |
950 | { | |
70b97a7f | 951 | struct rq *rq; |
1da177e4 | 952 | |
3a5c359a AK |
953 | for (;;) { |
954 | local_irq_save(*flags); | |
955 | rq = task_rq(p); | |
05fa785c | 956 | raw_spin_lock(&rq->lock); |
65cc8e48 | 957 | if (likely(rq == task_rq(p))) |
3a5c359a | 958 | return rq; |
05fa785c | 959 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 960 | } |
1da177e4 LT |
961 | } |
962 | ||
ad474cac ON |
963 | void task_rq_unlock_wait(struct task_struct *p) |
964 | { | |
965 | struct rq *rq = task_rq(p); | |
966 | ||
967 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
05fa785c | 968 | raw_spin_unlock_wait(&rq->lock); |
ad474cac ON |
969 | } |
970 | ||
a9957449 | 971 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
972 | __releases(rq->lock) |
973 | { | |
05fa785c | 974 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
975 | } |
976 | ||
70b97a7f | 977 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
978 | __releases(rq->lock) |
979 | { | |
05fa785c | 980 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 LT |
981 | } |
982 | ||
1da177e4 | 983 | /* |
cc2a73b5 | 984 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 985 | */ |
a9957449 | 986 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
987 | __acquires(rq->lock) |
988 | { | |
70b97a7f | 989 | struct rq *rq; |
1da177e4 LT |
990 | |
991 | local_irq_disable(); | |
992 | rq = this_rq(); | |
05fa785c | 993 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
994 | |
995 | return rq; | |
996 | } | |
997 | ||
8f4d37ec PZ |
998 | #ifdef CONFIG_SCHED_HRTICK |
999 | /* | |
1000 | * Use HR-timers to deliver accurate preemption points. | |
1001 | * | |
1002 | * Its all a bit involved since we cannot program an hrt while holding the | |
1003 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1004 | * reschedule event. | |
1005 | * | |
1006 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1007 | * rq->lock. | |
1008 | */ | |
8f4d37ec PZ |
1009 | |
1010 | /* | |
1011 | * Use hrtick when: | |
1012 | * - enabled by features | |
1013 | * - hrtimer is actually high res | |
1014 | */ | |
1015 | static inline int hrtick_enabled(struct rq *rq) | |
1016 | { | |
1017 | if (!sched_feat(HRTICK)) | |
1018 | return 0; | |
ba42059f | 1019 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1020 | return 0; |
8f4d37ec PZ |
1021 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1022 | } | |
1023 | ||
8f4d37ec PZ |
1024 | static void hrtick_clear(struct rq *rq) |
1025 | { | |
1026 | if (hrtimer_active(&rq->hrtick_timer)) | |
1027 | hrtimer_cancel(&rq->hrtick_timer); | |
1028 | } | |
1029 | ||
8f4d37ec PZ |
1030 | /* |
1031 | * High-resolution timer tick. | |
1032 | * Runs from hardirq context with interrupts disabled. | |
1033 | */ | |
1034 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1035 | { | |
1036 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1037 | ||
1038 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1039 | ||
05fa785c | 1040 | raw_spin_lock(&rq->lock); |
3e51f33f | 1041 | update_rq_clock(rq); |
8f4d37ec | 1042 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1043 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1044 | |
1045 | return HRTIMER_NORESTART; | |
1046 | } | |
1047 | ||
95e904c7 | 1048 | #ifdef CONFIG_SMP |
31656519 PZ |
1049 | /* |
1050 | * called from hardirq (IPI) context | |
1051 | */ | |
1052 | static void __hrtick_start(void *arg) | |
b328ca18 | 1053 | { |
31656519 | 1054 | struct rq *rq = arg; |
b328ca18 | 1055 | |
05fa785c | 1056 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1057 | hrtimer_restart(&rq->hrtick_timer); |
1058 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1059 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1060 | } |
1061 | ||
31656519 PZ |
1062 | /* |
1063 | * Called to set the hrtick timer state. | |
1064 | * | |
1065 | * called with rq->lock held and irqs disabled | |
1066 | */ | |
1067 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1068 | { |
31656519 PZ |
1069 | struct hrtimer *timer = &rq->hrtick_timer; |
1070 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1071 | |
cc584b21 | 1072 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1073 | |
1074 | if (rq == this_rq()) { | |
1075 | hrtimer_restart(timer); | |
1076 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1077 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1078 | rq->hrtick_csd_pending = 1; |
1079 | } | |
b328ca18 PZ |
1080 | } |
1081 | ||
1082 | static int | |
1083 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1084 | { | |
1085 | int cpu = (int)(long)hcpu; | |
1086 | ||
1087 | switch (action) { | |
1088 | case CPU_UP_CANCELED: | |
1089 | case CPU_UP_CANCELED_FROZEN: | |
1090 | case CPU_DOWN_PREPARE: | |
1091 | case CPU_DOWN_PREPARE_FROZEN: | |
1092 | case CPU_DEAD: | |
1093 | case CPU_DEAD_FROZEN: | |
31656519 | 1094 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1095 | return NOTIFY_OK; |
1096 | } | |
1097 | ||
1098 | return NOTIFY_DONE; | |
1099 | } | |
1100 | ||
fa748203 | 1101 | static __init void init_hrtick(void) |
b328ca18 PZ |
1102 | { |
1103 | hotcpu_notifier(hotplug_hrtick, 0); | |
1104 | } | |
31656519 PZ |
1105 | #else |
1106 | /* | |
1107 | * Called to set the hrtick timer state. | |
1108 | * | |
1109 | * called with rq->lock held and irqs disabled | |
1110 | */ | |
1111 | static void hrtick_start(struct rq *rq, u64 delay) | |
1112 | { | |
7f1e2ca9 | 1113 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1114 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1115 | } |
b328ca18 | 1116 | |
006c75f1 | 1117 | static inline void init_hrtick(void) |
8f4d37ec | 1118 | { |
8f4d37ec | 1119 | } |
31656519 | 1120 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1121 | |
31656519 | 1122 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1123 | { |
31656519 PZ |
1124 | #ifdef CONFIG_SMP |
1125 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1126 | |
31656519 PZ |
1127 | rq->hrtick_csd.flags = 0; |
1128 | rq->hrtick_csd.func = __hrtick_start; | |
1129 | rq->hrtick_csd.info = rq; | |
1130 | #endif | |
8f4d37ec | 1131 | |
31656519 PZ |
1132 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1133 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1134 | } |
006c75f1 | 1135 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1136 | static inline void hrtick_clear(struct rq *rq) |
1137 | { | |
1138 | } | |
1139 | ||
8f4d37ec PZ |
1140 | static inline void init_rq_hrtick(struct rq *rq) |
1141 | { | |
1142 | } | |
1143 | ||
b328ca18 PZ |
1144 | static inline void init_hrtick(void) |
1145 | { | |
1146 | } | |
006c75f1 | 1147 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1148 | |
c24d20db IM |
1149 | /* |
1150 | * resched_task - mark a task 'to be rescheduled now'. | |
1151 | * | |
1152 | * On UP this means the setting of the need_resched flag, on SMP it | |
1153 | * might also involve a cross-CPU call to trigger the scheduler on | |
1154 | * the target CPU. | |
1155 | */ | |
1156 | #ifdef CONFIG_SMP | |
1157 | ||
1158 | #ifndef tsk_is_polling | |
1159 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1160 | #endif | |
1161 | ||
31656519 | 1162 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1163 | { |
1164 | int cpu; | |
1165 | ||
05fa785c | 1166 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1167 | |
5ed0cec0 | 1168 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1169 | return; |
1170 | ||
5ed0cec0 | 1171 | set_tsk_need_resched(p); |
c24d20db IM |
1172 | |
1173 | cpu = task_cpu(p); | |
1174 | if (cpu == smp_processor_id()) | |
1175 | return; | |
1176 | ||
1177 | /* NEED_RESCHED must be visible before we test polling */ | |
1178 | smp_mb(); | |
1179 | if (!tsk_is_polling(p)) | |
1180 | smp_send_reschedule(cpu); | |
1181 | } | |
1182 | ||
1183 | static void resched_cpu(int cpu) | |
1184 | { | |
1185 | struct rq *rq = cpu_rq(cpu); | |
1186 | unsigned long flags; | |
1187 | ||
05fa785c | 1188 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1189 | return; |
1190 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1191 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1192 | } |
06d8308c TG |
1193 | |
1194 | #ifdef CONFIG_NO_HZ | |
1195 | /* | |
1196 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1197 | * idle CPU then this timer might expire before the next timer event | |
1198 | * which is scheduled to wake up that CPU. In case of a completely | |
1199 | * idle system the next event might even be infinite time into the | |
1200 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1201 | * leaves the inner idle loop so the newly added timer is taken into | |
1202 | * account when the CPU goes back to idle and evaluates the timer | |
1203 | * wheel for the next timer event. | |
1204 | */ | |
1205 | void wake_up_idle_cpu(int cpu) | |
1206 | { | |
1207 | struct rq *rq = cpu_rq(cpu); | |
1208 | ||
1209 | if (cpu == smp_processor_id()) | |
1210 | return; | |
1211 | ||
1212 | /* | |
1213 | * This is safe, as this function is called with the timer | |
1214 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1215 | * to idle and has not yet set rq->curr to idle then it will | |
1216 | * be serialized on the timer wheel base lock and take the new | |
1217 | * timer into account automatically. | |
1218 | */ | |
1219 | if (rq->curr != rq->idle) | |
1220 | return; | |
1221 | ||
1222 | /* | |
1223 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1224 | * lockless. The worst case is that the other CPU runs the | |
1225 | * idle task through an additional NOOP schedule() | |
1226 | */ | |
5ed0cec0 | 1227 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1228 | |
1229 | /* NEED_RESCHED must be visible before we test polling */ | |
1230 | smp_mb(); | |
1231 | if (!tsk_is_polling(rq->idle)) | |
1232 | smp_send_reschedule(cpu); | |
1233 | } | |
39c0cbe2 MG |
1234 | |
1235 | int nohz_ratelimit(int cpu) | |
1236 | { | |
1237 | struct rq *rq = cpu_rq(cpu); | |
1238 | u64 diff = rq->clock - rq->nohz_stamp; | |
1239 | ||
1240 | rq->nohz_stamp = rq->clock; | |
1241 | ||
1242 | return diff < (NSEC_PER_SEC / HZ) >> 1; | |
1243 | } | |
1244 | ||
6d6bc0ad | 1245 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1246 | |
e9e9250b PZ |
1247 | static u64 sched_avg_period(void) |
1248 | { | |
1249 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1250 | } | |
1251 | ||
1252 | static void sched_avg_update(struct rq *rq) | |
1253 | { | |
1254 | s64 period = sched_avg_period(); | |
1255 | ||
1256 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
1257 | rq->age_stamp += period; | |
1258 | rq->rt_avg /= 2; | |
1259 | } | |
1260 | } | |
1261 | ||
1262 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1263 | { | |
1264 | rq->rt_avg += rt_delta; | |
1265 | sched_avg_update(rq); | |
1266 | } | |
1267 | ||
6d6bc0ad | 1268 | #else /* !CONFIG_SMP */ |
31656519 | 1269 | static void resched_task(struct task_struct *p) |
c24d20db | 1270 | { |
05fa785c | 1271 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1272 | set_tsk_need_resched(p); |
c24d20db | 1273 | } |
e9e9250b PZ |
1274 | |
1275 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1276 | { | |
1277 | } | |
6d6bc0ad | 1278 | #endif /* CONFIG_SMP */ |
c24d20db | 1279 | |
45bf76df IM |
1280 | #if BITS_PER_LONG == 32 |
1281 | # define WMULT_CONST (~0UL) | |
1282 | #else | |
1283 | # define WMULT_CONST (1UL << 32) | |
1284 | #endif | |
1285 | ||
1286 | #define WMULT_SHIFT 32 | |
1287 | ||
194081eb IM |
1288 | /* |
1289 | * Shift right and round: | |
1290 | */ | |
cf2ab469 | 1291 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1292 | |
a7be37ac PZ |
1293 | /* |
1294 | * delta *= weight / lw | |
1295 | */ | |
cb1c4fc9 | 1296 | static unsigned long |
45bf76df IM |
1297 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1298 | struct load_weight *lw) | |
1299 | { | |
1300 | u64 tmp; | |
1301 | ||
7a232e03 LJ |
1302 | if (!lw->inv_weight) { |
1303 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1304 | lw->inv_weight = 1; | |
1305 | else | |
1306 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1307 | / (lw->weight+1); | |
1308 | } | |
45bf76df IM |
1309 | |
1310 | tmp = (u64)delta_exec * weight; | |
1311 | /* | |
1312 | * Check whether we'd overflow the 64-bit multiplication: | |
1313 | */ | |
194081eb | 1314 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1315 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1316 | WMULT_SHIFT/2); |
1317 | else | |
cf2ab469 | 1318 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1319 | |
ecf691da | 1320 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1321 | } |
1322 | ||
1091985b | 1323 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1324 | { |
1325 | lw->weight += inc; | |
e89996ae | 1326 | lw->inv_weight = 0; |
45bf76df IM |
1327 | } |
1328 | ||
1091985b | 1329 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1330 | { |
1331 | lw->weight -= dec; | |
e89996ae | 1332 | lw->inv_weight = 0; |
45bf76df IM |
1333 | } |
1334 | ||
2dd73a4f PW |
1335 | /* |
1336 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1337 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1338 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1339 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1340 | * scaled version of the new time slice allocation that they receive on time |
1341 | * slice expiry etc. | |
1342 | */ | |
1343 | ||
cce7ade8 PZ |
1344 | #define WEIGHT_IDLEPRIO 3 |
1345 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1346 | |
1347 | /* | |
1348 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1349 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1350 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1351 | * that remained on nice 0. | |
1352 | * | |
1353 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1354 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1355 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1356 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1357 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1358 | */ |
1359 | static const int prio_to_weight[40] = { | |
254753dc IM |
1360 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1361 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1362 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1363 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1364 | /* 0 */ 1024, 820, 655, 526, 423, | |
1365 | /* 5 */ 335, 272, 215, 172, 137, | |
1366 | /* 10 */ 110, 87, 70, 56, 45, | |
1367 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1368 | }; |
1369 | ||
5714d2de IM |
1370 | /* |
1371 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1372 | * | |
1373 | * In cases where the weight does not change often, we can use the | |
1374 | * precalculated inverse to speed up arithmetics by turning divisions | |
1375 | * into multiplications: | |
1376 | */ | |
dd41f596 | 1377 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1378 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1379 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1380 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1381 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1382 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1383 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1384 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1385 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1386 | }; |
2dd73a4f | 1387 | |
ef12fefa BR |
1388 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1389 | enum cpuacct_stat_index { | |
1390 | CPUACCT_STAT_USER, /* ... user mode */ | |
1391 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1392 | ||
1393 | CPUACCT_STAT_NSTATS, | |
1394 | }; | |
1395 | ||
d842de87 SV |
1396 | #ifdef CONFIG_CGROUP_CPUACCT |
1397 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1398 | static void cpuacct_update_stats(struct task_struct *tsk, |
1399 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1400 | #else |
1401 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1402 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1403 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1404 | #endif |
1405 | ||
18d95a28 PZ |
1406 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1407 | { | |
1408 | update_load_add(&rq->load, load); | |
1409 | } | |
1410 | ||
1411 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1412 | { | |
1413 | update_load_sub(&rq->load, load); | |
1414 | } | |
1415 | ||
7940ca36 | 1416 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1417 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1418 | |
1419 | /* | |
1420 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1421 | * leaving it for the final time. | |
1422 | */ | |
eb755805 | 1423 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1424 | { |
1425 | struct task_group *parent, *child; | |
eb755805 | 1426 | int ret; |
c09595f6 PZ |
1427 | |
1428 | rcu_read_lock(); | |
1429 | parent = &root_task_group; | |
1430 | down: | |
eb755805 PZ |
1431 | ret = (*down)(parent, data); |
1432 | if (ret) | |
1433 | goto out_unlock; | |
c09595f6 PZ |
1434 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1435 | parent = child; | |
1436 | goto down; | |
1437 | ||
1438 | up: | |
1439 | continue; | |
1440 | } | |
eb755805 PZ |
1441 | ret = (*up)(parent, data); |
1442 | if (ret) | |
1443 | goto out_unlock; | |
c09595f6 PZ |
1444 | |
1445 | child = parent; | |
1446 | parent = parent->parent; | |
1447 | if (parent) | |
1448 | goto up; | |
eb755805 | 1449 | out_unlock: |
c09595f6 | 1450 | rcu_read_unlock(); |
eb755805 PZ |
1451 | |
1452 | return ret; | |
c09595f6 PZ |
1453 | } |
1454 | ||
eb755805 PZ |
1455 | static int tg_nop(struct task_group *tg, void *data) |
1456 | { | |
1457 | return 0; | |
c09595f6 | 1458 | } |
eb755805 PZ |
1459 | #endif |
1460 | ||
1461 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1462 | /* Used instead of source_load when we know the type == 0 */ |
1463 | static unsigned long weighted_cpuload(const int cpu) | |
1464 | { | |
1465 | return cpu_rq(cpu)->load.weight; | |
1466 | } | |
1467 | ||
1468 | /* | |
1469 | * Return a low guess at the load of a migration-source cpu weighted | |
1470 | * according to the scheduling class and "nice" value. | |
1471 | * | |
1472 | * We want to under-estimate the load of migration sources, to | |
1473 | * balance conservatively. | |
1474 | */ | |
1475 | static unsigned long source_load(int cpu, int type) | |
1476 | { | |
1477 | struct rq *rq = cpu_rq(cpu); | |
1478 | unsigned long total = weighted_cpuload(cpu); | |
1479 | ||
1480 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1481 | return total; | |
1482 | ||
1483 | return min(rq->cpu_load[type-1], total); | |
1484 | } | |
1485 | ||
1486 | /* | |
1487 | * Return a high guess at the load of a migration-target cpu weighted | |
1488 | * according to the scheduling class and "nice" value. | |
1489 | */ | |
1490 | static unsigned long target_load(int cpu, int type) | |
1491 | { | |
1492 | struct rq *rq = cpu_rq(cpu); | |
1493 | unsigned long total = weighted_cpuload(cpu); | |
1494 | ||
1495 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1496 | return total; | |
1497 | ||
1498 | return max(rq->cpu_load[type-1], total); | |
1499 | } | |
1500 | ||
ae154be1 PZ |
1501 | static struct sched_group *group_of(int cpu) |
1502 | { | |
d11c563d | 1503 | struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd); |
ae154be1 PZ |
1504 | |
1505 | if (!sd) | |
1506 | return NULL; | |
1507 | ||
1508 | return sd->groups; | |
1509 | } | |
1510 | ||
1511 | static unsigned long power_of(int cpu) | |
1512 | { | |
1513 | struct sched_group *group = group_of(cpu); | |
1514 | ||
1515 | if (!group) | |
1516 | return SCHED_LOAD_SCALE; | |
1517 | ||
1518 | return group->cpu_power; | |
1519 | } | |
1520 | ||
eb755805 PZ |
1521 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1522 | ||
1523 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1524 | { | |
1525 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1526 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1527 | |
4cd42620 SR |
1528 | if (nr_running) |
1529 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1530 | else |
1531 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1532 | |
1533 | return rq->avg_load_per_task; | |
1534 | } | |
1535 | ||
1536 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1537 | |
43cf38eb | 1538 | static __read_mostly unsigned long __percpu *update_shares_data; |
34d76c41 | 1539 | |
c09595f6 PZ |
1540 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1541 | ||
1542 | /* | |
1543 | * Calculate and set the cpu's group shares. | |
1544 | */ | |
34d76c41 PZ |
1545 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1546 | unsigned long sd_shares, | |
1547 | unsigned long sd_rq_weight, | |
4a6cc4bd | 1548 | unsigned long *usd_rq_weight) |
18d95a28 | 1549 | { |
34d76c41 | 1550 | unsigned long shares, rq_weight; |
a5004278 | 1551 | int boost = 0; |
c09595f6 | 1552 | |
4a6cc4bd | 1553 | rq_weight = usd_rq_weight[cpu]; |
a5004278 PZ |
1554 | if (!rq_weight) { |
1555 | boost = 1; | |
1556 | rq_weight = NICE_0_LOAD; | |
1557 | } | |
c8cba857 | 1558 | |
c09595f6 | 1559 | /* |
a8af7246 PZ |
1560 | * \Sum_j shares_j * rq_weight_i |
1561 | * shares_i = ----------------------------- | |
1562 | * \Sum_j rq_weight_j | |
c09595f6 | 1563 | */ |
ec4e0e2f | 1564 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1565 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1566 | |
ffda12a1 PZ |
1567 | if (abs(shares - tg->se[cpu]->load.weight) > |
1568 | sysctl_sched_shares_thresh) { | |
1569 | struct rq *rq = cpu_rq(cpu); | |
1570 | unsigned long flags; | |
c09595f6 | 1571 | |
05fa785c | 1572 | raw_spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1573 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1574 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 | 1575 | __set_se_shares(tg->se[cpu], shares); |
05fa785c | 1576 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
ffda12a1 | 1577 | } |
18d95a28 | 1578 | } |
c09595f6 PZ |
1579 | |
1580 | /* | |
c8cba857 PZ |
1581 | * Re-compute the task group their per cpu shares over the given domain. |
1582 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1583 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1584 | */ |
eb755805 | 1585 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1586 | { |
cd8ad40d | 1587 | unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; |
4a6cc4bd | 1588 | unsigned long *usd_rq_weight; |
eb755805 | 1589 | struct sched_domain *sd = data; |
34d76c41 | 1590 | unsigned long flags; |
c8cba857 | 1591 | int i; |
c09595f6 | 1592 | |
34d76c41 PZ |
1593 | if (!tg->se[0]) |
1594 | return 0; | |
1595 | ||
1596 | local_irq_save(flags); | |
4a6cc4bd | 1597 | usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); |
34d76c41 | 1598 | |
758b2cdc | 1599 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 | 1600 | weight = tg->cfs_rq[i]->load.weight; |
4a6cc4bd | 1601 | usd_rq_weight[i] = weight; |
34d76c41 | 1602 | |
cd8ad40d | 1603 | rq_weight += weight; |
ec4e0e2f KC |
1604 | /* |
1605 | * If there are currently no tasks on the cpu pretend there | |
1606 | * is one of average load so that when a new task gets to | |
1607 | * run here it will not get delayed by group starvation. | |
1608 | */ | |
ec4e0e2f KC |
1609 | if (!weight) |
1610 | weight = NICE_0_LOAD; | |
1611 | ||
cd8ad40d | 1612 | sum_weight += weight; |
c8cba857 | 1613 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1614 | } |
c09595f6 | 1615 | |
cd8ad40d PZ |
1616 | if (!rq_weight) |
1617 | rq_weight = sum_weight; | |
1618 | ||
c8cba857 PZ |
1619 | if ((!shares && rq_weight) || shares > tg->shares) |
1620 | shares = tg->shares; | |
1621 | ||
1622 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1623 | shares = tg->shares; | |
c09595f6 | 1624 | |
758b2cdc | 1625 | for_each_cpu(i, sched_domain_span(sd)) |
4a6cc4bd | 1626 | update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); |
34d76c41 PZ |
1627 | |
1628 | local_irq_restore(flags); | |
eb755805 PZ |
1629 | |
1630 | return 0; | |
c09595f6 PZ |
1631 | } |
1632 | ||
1633 | /* | |
c8cba857 PZ |
1634 | * Compute the cpu's hierarchical load factor for each task group. |
1635 | * This needs to be done in a top-down fashion because the load of a child | |
1636 | * group is a fraction of its parents load. | |
c09595f6 | 1637 | */ |
eb755805 | 1638 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1639 | { |
c8cba857 | 1640 | unsigned long load; |
eb755805 | 1641 | long cpu = (long)data; |
c09595f6 | 1642 | |
c8cba857 PZ |
1643 | if (!tg->parent) { |
1644 | load = cpu_rq(cpu)->load.weight; | |
1645 | } else { | |
1646 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1647 | load *= tg->cfs_rq[cpu]->shares; | |
1648 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1649 | } | |
c09595f6 | 1650 | |
c8cba857 | 1651 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1652 | |
eb755805 | 1653 | return 0; |
c09595f6 PZ |
1654 | } |
1655 | ||
c8cba857 | 1656 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1657 | { |
e7097159 PZ |
1658 | s64 elapsed; |
1659 | u64 now; | |
1660 | ||
1661 | if (root_task_group_empty()) | |
1662 | return; | |
1663 | ||
1664 | now = cpu_clock(raw_smp_processor_id()); | |
1665 | elapsed = now - sd->last_update; | |
2398f2c6 PZ |
1666 | |
1667 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1668 | sd->last_update = now; | |
eb755805 | 1669 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1670 | } |
4d8d595d PZ |
1671 | } |
1672 | ||
eb755805 | 1673 | static void update_h_load(long cpu) |
c09595f6 | 1674 | { |
e7097159 PZ |
1675 | if (root_task_group_empty()) |
1676 | return; | |
1677 | ||
eb755805 | 1678 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1679 | } |
1680 | ||
c09595f6 PZ |
1681 | #else |
1682 | ||
c8cba857 | 1683 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1684 | { |
1685 | } | |
1686 | ||
18d95a28 PZ |
1687 | #endif |
1688 | ||
8f45e2b5 GH |
1689 | #ifdef CONFIG_PREEMPT |
1690 | ||
b78bb868 PZ |
1691 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1692 | ||
70574a99 | 1693 | /* |
8f45e2b5 GH |
1694 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1695 | * way at the expense of forcing extra atomic operations in all | |
1696 | * invocations. This assures that the double_lock is acquired using the | |
1697 | * same underlying policy as the spinlock_t on this architecture, which | |
1698 | * reduces latency compared to the unfair variant below. However, it | |
1699 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1700 | */ |
8f45e2b5 GH |
1701 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1702 | __releases(this_rq->lock) | |
1703 | __acquires(busiest->lock) | |
1704 | __acquires(this_rq->lock) | |
1705 | { | |
05fa785c | 1706 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1707 | double_rq_lock(this_rq, busiest); |
1708 | ||
1709 | return 1; | |
1710 | } | |
1711 | ||
1712 | #else | |
1713 | /* | |
1714 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1715 | * latency by eliminating extra atomic operations when the locks are | |
1716 | * already in proper order on entry. This favors lower cpu-ids and will | |
1717 | * grant the double lock to lower cpus over higher ids under contention, | |
1718 | * regardless of entry order into the function. | |
1719 | */ | |
1720 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1721 | __releases(this_rq->lock) |
1722 | __acquires(busiest->lock) | |
1723 | __acquires(this_rq->lock) | |
1724 | { | |
1725 | int ret = 0; | |
1726 | ||
05fa785c | 1727 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1728 | if (busiest < this_rq) { |
05fa785c TG |
1729 | raw_spin_unlock(&this_rq->lock); |
1730 | raw_spin_lock(&busiest->lock); | |
1731 | raw_spin_lock_nested(&this_rq->lock, | |
1732 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1733 | ret = 1; |
1734 | } else | |
05fa785c TG |
1735 | raw_spin_lock_nested(&busiest->lock, |
1736 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1737 | } |
1738 | return ret; | |
1739 | } | |
1740 | ||
8f45e2b5 GH |
1741 | #endif /* CONFIG_PREEMPT */ |
1742 | ||
1743 | /* | |
1744 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1745 | */ | |
1746 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1747 | { | |
1748 | if (unlikely(!irqs_disabled())) { | |
1749 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1750 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1751 | BUG_ON(1); |
1752 | } | |
1753 | ||
1754 | return _double_lock_balance(this_rq, busiest); | |
1755 | } | |
1756 | ||
70574a99 AD |
1757 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1758 | __releases(busiest->lock) | |
1759 | { | |
05fa785c | 1760 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1761 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1762 | } | |
1e3c88bd PZ |
1763 | |
1764 | /* | |
1765 | * double_rq_lock - safely lock two runqueues | |
1766 | * | |
1767 | * Note this does not disable interrupts like task_rq_lock, | |
1768 | * you need to do so manually before calling. | |
1769 | */ | |
1770 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1771 | __acquires(rq1->lock) | |
1772 | __acquires(rq2->lock) | |
1773 | { | |
1774 | BUG_ON(!irqs_disabled()); | |
1775 | if (rq1 == rq2) { | |
1776 | raw_spin_lock(&rq1->lock); | |
1777 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1778 | } else { | |
1779 | if (rq1 < rq2) { | |
1780 | raw_spin_lock(&rq1->lock); | |
1781 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1782 | } else { | |
1783 | raw_spin_lock(&rq2->lock); | |
1784 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1785 | } | |
1786 | } | |
1e3c88bd PZ |
1787 | } |
1788 | ||
1789 | /* | |
1790 | * double_rq_unlock - safely unlock two runqueues | |
1791 | * | |
1792 | * Note this does not restore interrupts like task_rq_unlock, | |
1793 | * you need to do so manually after calling. | |
1794 | */ | |
1795 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1796 | __releases(rq1->lock) | |
1797 | __releases(rq2->lock) | |
1798 | { | |
1799 | raw_spin_unlock(&rq1->lock); | |
1800 | if (rq1 != rq2) | |
1801 | raw_spin_unlock(&rq2->lock); | |
1802 | else | |
1803 | __release(rq2->lock); | |
1804 | } | |
1805 | ||
18d95a28 PZ |
1806 | #endif |
1807 | ||
30432094 | 1808 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1809 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1810 | { | |
30432094 | 1811 | #ifdef CONFIG_SMP |
34e83e85 IM |
1812 | cfs_rq->shares = shares; |
1813 | #endif | |
1814 | } | |
30432094 | 1815 | #endif |
e7693a36 | 1816 | |
dce48a84 | 1817 | static void calc_load_account_active(struct rq *this_rq); |
0bcdcf28 | 1818 | static void update_sysctl(void); |
acb4a848 | 1819 | static int get_update_sysctl_factor(void); |
dce48a84 | 1820 | |
cd29fe6f PZ |
1821 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1822 | { | |
1823 | set_task_rq(p, cpu); | |
1824 | #ifdef CONFIG_SMP | |
1825 | /* | |
1826 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1827 | * successfuly executed on another CPU. We must ensure that updates of | |
1828 | * per-task data have been completed by this moment. | |
1829 | */ | |
1830 | smp_wmb(); | |
1831 | task_thread_info(p)->cpu = cpu; | |
1832 | #endif | |
1833 | } | |
dce48a84 | 1834 | |
1e3c88bd | 1835 | static const struct sched_class rt_sched_class; |
dd41f596 IM |
1836 | |
1837 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1838 | #define for_each_class(class) \ |
1839 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1840 | |
1e3c88bd PZ |
1841 | #include "sched_stats.h" |
1842 | ||
c09595f6 | 1843 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1844 | { |
1845 | rq->nr_running++; | |
9c217245 IM |
1846 | } |
1847 | ||
c09595f6 | 1848 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1849 | { |
1850 | rq->nr_running--; | |
9c217245 IM |
1851 | } |
1852 | ||
45bf76df IM |
1853 | static void set_load_weight(struct task_struct *p) |
1854 | { | |
1855 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1856 | p->se.load.weight = prio_to_weight[0] * 2; |
1857 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1858 | return; | |
1859 | } | |
45bf76df | 1860 | |
dd41f596 IM |
1861 | /* |
1862 | * SCHED_IDLE tasks get minimal weight: | |
1863 | */ | |
1864 | if (p->policy == SCHED_IDLE) { | |
1865 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1866 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1867 | return; | |
1868 | } | |
71f8bd46 | 1869 | |
dd41f596 IM |
1870 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1871 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1872 | } |
1873 | ||
2087a1ad GH |
1874 | static void update_avg(u64 *avg, u64 sample) |
1875 | { | |
1876 | s64 diff = sample - *avg; | |
1877 | *avg += diff >> 3; | |
1878 | } | |
1879 | ||
ea87bb78 TG |
1880 | static void |
1881 | enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) | |
71f8bd46 | 1882 | { |
a64692a3 | 1883 | update_rq_clock(rq); |
dd41f596 | 1884 | sched_info_queued(p); |
ea87bb78 | 1885 | p->sched_class->enqueue_task(rq, p, wakeup, head); |
dd41f596 | 1886 | p->se.on_rq = 1; |
71f8bd46 IM |
1887 | } |
1888 | ||
69be72c1 | 1889 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1890 | { |
a64692a3 | 1891 | update_rq_clock(rq); |
46ac22ba | 1892 | sched_info_dequeued(p); |
f02231e5 | 1893 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1894 | p->se.on_rq = 0; |
71f8bd46 IM |
1895 | } |
1896 | ||
1e3c88bd PZ |
1897 | /* |
1898 | * activate_task - move a task to the runqueue. | |
1899 | */ | |
1900 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) | |
1901 | { | |
1902 | if (task_contributes_to_load(p)) | |
1903 | rq->nr_uninterruptible--; | |
1904 | ||
ea87bb78 | 1905 | enqueue_task(rq, p, wakeup, false); |
1e3c88bd PZ |
1906 | inc_nr_running(rq); |
1907 | } | |
1908 | ||
1909 | /* | |
1910 | * deactivate_task - remove a task from the runqueue. | |
1911 | */ | |
1912 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) | |
1913 | { | |
1914 | if (task_contributes_to_load(p)) | |
1915 | rq->nr_uninterruptible++; | |
1916 | ||
1917 | dequeue_task(rq, p, sleep); | |
1918 | dec_nr_running(rq); | |
1919 | } | |
1920 | ||
1921 | #include "sched_idletask.c" | |
1922 | #include "sched_fair.c" | |
1923 | #include "sched_rt.c" | |
1924 | #ifdef CONFIG_SCHED_DEBUG | |
1925 | # include "sched_debug.c" | |
1926 | #endif | |
1927 | ||
14531189 | 1928 | /* |
dd41f596 | 1929 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1930 | */ |
14531189 IM |
1931 | static inline int __normal_prio(struct task_struct *p) |
1932 | { | |
dd41f596 | 1933 | return p->static_prio; |
14531189 IM |
1934 | } |
1935 | ||
b29739f9 IM |
1936 | /* |
1937 | * Calculate the expected normal priority: i.e. priority | |
1938 | * without taking RT-inheritance into account. Might be | |
1939 | * boosted by interactivity modifiers. Changes upon fork, | |
1940 | * setprio syscalls, and whenever the interactivity | |
1941 | * estimator recalculates. | |
1942 | */ | |
36c8b586 | 1943 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1944 | { |
1945 | int prio; | |
1946 | ||
e05606d3 | 1947 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1948 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1949 | else | |
1950 | prio = __normal_prio(p); | |
1951 | return prio; | |
1952 | } | |
1953 | ||
1954 | /* | |
1955 | * Calculate the current priority, i.e. the priority | |
1956 | * taken into account by the scheduler. This value might | |
1957 | * be boosted by RT tasks, or might be boosted by | |
1958 | * interactivity modifiers. Will be RT if the task got | |
1959 | * RT-boosted. If not then it returns p->normal_prio. | |
1960 | */ | |
36c8b586 | 1961 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1962 | { |
1963 | p->normal_prio = normal_prio(p); | |
1964 | /* | |
1965 | * If we are RT tasks or we were boosted to RT priority, | |
1966 | * keep the priority unchanged. Otherwise, update priority | |
1967 | * to the normal priority: | |
1968 | */ | |
1969 | if (!rt_prio(p->prio)) | |
1970 | return p->normal_prio; | |
1971 | return p->prio; | |
1972 | } | |
1973 | ||
1da177e4 LT |
1974 | /** |
1975 | * task_curr - is this task currently executing on a CPU? | |
1976 | * @p: the task in question. | |
1977 | */ | |
36c8b586 | 1978 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1979 | { |
1980 | return cpu_curr(task_cpu(p)) == p; | |
1981 | } | |
1982 | ||
cb469845 SR |
1983 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1984 | const struct sched_class *prev_class, | |
1985 | int oldprio, int running) | |
1986 | { | |
1987 | if (prev_class != p->sched_class) { | |
1988 | if (prev_class->switched_from) | |
1989 | prev_class->switched_from(rq, p, running); | |
1990 | p->sched_class->switched_to(rq, p, running); | |
1991 | } else | |
1992 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1993 | } | |
1994 | ||
1da177e4 | 1995 | #ifdef CONFIG_SMP |
cc367732 IM |
1996 | /* |
1997 | * Is this task likely cache-hot: | |
1998 | */ | |
e7693a36 | 1999 | static int |
cc367732 IM |
2000 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2001 | { | |
2002 | s64 delta; | |
2003 | ||
e6c8fba7 PZ |
2004 | if (p->sched_class != &fair_sched_class) |
2005 | return 0; | |
2006 | ||
f540a608 IM |
2007 | /* |
2008 | * Buddy candidates are cache hot: | |
2009 | */ | |
f685ceac | 2010 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2011 | (&p->se == cfs_rq_of(&p->se)->next || |
2012 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2013 | return 1; |
2014 | ||
6bc1665b IM |
2015 | if (sysctl_sched_migration_cost == -1) |
2016 | return 1; | |
2017 | if (sysctl_sched_migration_cost == 0) | |
2018 | return 0; | |
2019 | ||
cc367732 IM |
2020 | delta = now - p->se.exec_start; |
2021 | ||
2022 | return delta < (s64)sysctl_sched_migration_cost; | |
2023 | } | |
2024 | ||
dd41f596 | 2025 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2026 | { |
e2912009 PZ |
2027 | #ifdef CONFIG_SCHED_DEBUG |
2028 | /* | |
2029 | * We should never call set_task_cpu() on a blocked task, | |
2030 | * ttwu() will sort out the placement. | |
2031 | */ | |
077614ee PZ |
2032 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2033 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
e2912009 PZ |
2034 | #endif |
2035 | ||
de1d7286 | 2036 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2037 | |
0c69774e PZ |
2038 | if (task_cpu(p) != new_cpu) { |
2039 | p->se.nr_migrations++; | |
2040 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); | |
2041 | } | |
dd41f596 IM |
2042 | |
2043 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2044 | } |
2045 | ||
70b97a7f | 2046 | struct migration_req { |
1da177e4 | 2047 | struct list_head list; |
1da177e4 | 2048 | |
36c8b586 | 2049 | struct task_struct *task; |
1da177e4 LT |
2050 | int dest_cpu; |
2051 | ||
1da177e4 | 2052 | struct completion done; |
70b97a7f | 2053 | }; |
1da177e4 LT |
2054 | |
2055 | /* | |
2056 | * The task's runqueue lock must be held. | |
2057 | * Returns true if you have to wait for migration thread. | |
2058 | */ | |
36c8b586 | 2059 | static int |
70b97a7f | 2060 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 2061 | { |
70b97a7f | 2062 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2063 | |
2064 | /* | |
2065 | * If the task is not on a runqueue (and not running), then | |
e2912009 | 2066 | * the next wake-up will properly place the task. |
1da177e4 | 2067 | */ |
e2912009 | 2068 | if (!p->se.on_rq && !task_running(rq, p)) |
1da177e4 | 2069 | return 0; |
1da177e4 LT |
2070 | |
2071 | init_completion(&req->done); | |
1da177e4 LT |
2072 | req->task = p; |
2073 | req->dest_cpu = dest_cpu; | |
2074 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 2075 | |
1da177e4 LT |
2076 | return 1; |
2077 | } | |
2078 | ||
a26b89f0 MM |
2079 | /* |
2080 | * wait_task_context_switch - wait for a thread to complete at least one | |
2081 | * context switch. | |
2082 | * | |
2083 | * @p must not be current. | |
2084 | */ | |
2085 | void wait_task_context_switch(struct task_struct *p) | |
2086 | { | |
2087 | unsigned long nvcsw, nivcsw, flags; | |
2088 | int running; | |
2089 | struct rq *rq; | |
2090 | ||
2091 | nvcsw = p->nvcsw; | |
2092 | nivcsw = p->nivcsw; | |
2093 | for (;;) { | |
2094 | /* | |
2095 | * The runqueue is assigned before the actual context | |
2096 | * switch. We need to take the runqueue lock. | |
2097 | * | |
2098 | * We could check initially without the lock but it is | |
2099 | * very likely that we need to take the lock in every | |
2100 | * iteration. | |
2101 | */ | |
2102 | rq = task_rq_lock(p, &flags); | |
2103 | running = task_running(rq, p); | |
2104 | task_rq_unlock(rq, &flags); | |
2105 | ||
2106 | if (likely(!running)) | |
2107 | break; | |
2108 | /* | |
2109 | * The switch count is incremented before the actual | |
2110 | * context switch. We thus wait for two switches to be | |
2111 | * sure at least one completed. | |
2112 | */ | |
2113 | if ((p->nvcsw - nvcsw) > 1) | |
2114 | break; | |
2115 | if ((p->nivcsw - nivcsw) > 1) | |
2116 | break; | |
2117 | ||
2118 | cpu_relax(); | |
2119 | } | |
2120 | } | |
2121 | ||
1da177e4 LT |
2122 | /* |
2123 | * wait_task_inactive - wait for a thread to unschedule. | |
2124 | * | |
85ba2d86 RM |
2125 | * If @match_state is nonzero, it's the @p->state value just checked and |
2126 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2127 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2128 | * we return a positive number (its total switch count). If a second call | |
2129 | * a short while later returns the same number, the caller can be sure that | |
2130 | * @p has remained unscheduled the whole time. | |
2131 | * | |
1da177e4 LT |
2132 | * The caller must ensure that the task *will* unschedule sometime soon, |
2133 | * else this function might spin for a *long* time. This function can't | |
2134 | * be called with interrupts off, or it may introduce deadlock with | |
2135 | * smp_call_function() if an IPI is sent by the same process we are | |
2136 | * waiting to become inactive. | |
2137 | */ | |
85ba2d86 | 2138 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2139 | { |
2140 | unsigned long flags; | |
dd41f596 | 2141 | int running, on_rq; |
85ba2d86 | 2142 | unsigned long ncsw; |
70b97a7f | 2143 | struct rq *rq; |
1da177e4 | 2144 | |
3a5c359a AK |
2145 | for (;;) { |
2146 | /* | |
2147 | * We do the initial early heuristics without holding | |
2148 | * any task-queue locks at all. We'll only try to get | |
2149 | * the runqueue lock when things look like they will | |
2150 | * work out! | |
2151 | */ | |
2152 | rq = task_rq(p); | |
fa490cfd | 2153 | |
3a5c359a AK |
2154 | /* |
2155 | * If the task is actively running on another CPU | |
2156 | * still, just relax and busy-wait without holding | |
2157 | * any locks. | |
2158 | * | |
2159 | * NOTE! Since we don't hold any locks, it's not | |
2160 | * even sure that "rq" stays as the right runqueue! | |
2161 | * But we don't care, since "task_running()" will | |
2162 | * return false if the runqueue has changed and p | |
2163 | * is actually now running somewhere else! | |
2164 | */ | |
85ba2d86 RM |
2165 | while (task_running(rq, p)) { |
2166 | if (match_state && unlikely(p->state != match_state)) | |
2167 | return 0; | |
3a5c359a | 2168 | cpu_relax(); |
85ba2d86 | 2169 | } |
fa490cfd | 2170 | |
3a5c359a AK |
2171 | /* |
2172 | * Ok, time to look more closely! We need the rq | |
2173 | * lock now, to be *sure*. If we're wrong, we'll | |
2174 | * just go back and repeat. | |
2175 | */ | |
2176 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 2177 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
2178 | running = task_running(rq, p); |
2179 | on_rq = p->se.on_rq; | |
85ba2d86 | 2180 | ncsw = 0; |
f31e11d8 | 2181 | if (!match_state || p->state == match_state) |
93dcf55f | 2182 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2183 | task_rq_unlock(rq, &flags); |
fa490cfd | 2184 | |
85ba2d86 RM |
2185 | /* |
2186 | * If it changed from the expected state, bail out now. | |
2187 | */ | |
2188 | if (unlikely(!ncsw)) | |
2189 | break; | |
2190 | ||
3a5c359a AK |
2191 | /* |
2192 | * Was it really running after all now that we | |
2193 | * checked with the proper locks actually held? | |
2194 | * | |
2195 | * Oops. Go back and try again.. | |
2196 | */ | |
2197 | if (unlikely(running)) { | |
2198 | cpu_relax(); | |
2199 | continue; | |
2200 | } | |
fa490cfd | 2201 | |
3a5c359a AK |
2202 | /* |
2203 | * It's not enough that it's not actively running, | |
2204 | * it must be off the runqueue _entirely_, and not | |
2205 | * preempted! | |
2206 | * | |
80dd99b3 | 2207 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2208 | * running right now), it's preempted, and we should |
2209 | * yield - it could be a while. | |
2210 | */ | |
2211 | if (unlikely(on_rq)) { | |
2212 | schedule_timeout_uninterruptible(1); | |
2213 | continue; | |
2214 | } | |
fa490cfd | 2215 | |
3a5c359a AK |
2216 | /* |
2217 | * Ahh, all good. It wasn't running, and it wasn't | |
2218 | * runnable, which means that it will never become | |
2219 | * running in the future either. We're all done! | |
2220 | */ | |
2221 | break; | |
2222 | } | |
85ba2d86 RM |
2223 | |
2224 | return ncsw; | |
1da177e4 LT |
2225 | } |
2226 | ||
2227 | /*** | |
2228 | * kick_process - kick a running thread to enter/exit the kernel | |
2229 | * @p: the to-be-kicked thread | |
2230 | * | |
2231 | * Cause a process which is running on another CPU to enter | |
2232 | * kernel-mode, without any delay. (to get signals handled.) | |
2233 | * | |
2234 | * NOTE: this function doesnt have to take the runqueue lock, | |
2235 | * because all it wants to ensure is that the remote task enters | |
2236 | * the kernel. If the IPI races and the task has been migrated | |
2237 | * to another CPU then no harm is done and the purpose has been | |
2238 | * achieved as well. | |
2239 | */ | |
36c8b586 | 2240 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2241 | { |
2242 | int cpu; | |
2243 | ||
2244 | preempt_disable(); | |
2245 | cpu = task_cpu(p); | |
2246 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2247 | smp_send_reschedule(cpu); | |
2248 | preempt_enable(); | |
2249 | } | |
b43e3521 | 2250 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2251 | #endif /* CONFIG_SMP */ |
1da177e4 | 2252 | |
0793a61d TG |
2253 | /** |
2254 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2255 | * @p: the task to evaluate | |
2256 | * @func: the function to be called | |
2257 | * @info: the function call argument | |
2258 | * | |
2259 | * Calls the function @func when the task is currently running. This might | |
2260 | * be on the current CPU, which just calls the function directly | |
2261 | */ | |
2262 | void task_oncpu_function_call(struct task_struct *p, | |
2263 | void (*func) (void *info), void *info) | |
2264 | { | |
2265 | int cpu; | |
2266 | ||
2267 | preempt_disable(); | |
2268 | cpu = task_cpu(p); | |
2269 | if (task_curr(p)) | |
2270 | smp_call_function_single(cpu, func, info, 1); | |
2271 | preempt_enable(); | |
2272 | } | |
2273 | ||
970b13ba | 2274 | #ifdef CONFIG_SMP |
30da688e ON |
2275 | /* |
2276 | * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held. | |
2277 | */ | |
5da9a0fb PZ |
2278 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2279 | { | |
2280 | int dest_cpu; | |
2281 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2282 | ||
2283 | /* Look for allowed, online CPU in same node. */ | |
2284 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2285 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2286 | return dest_cpu; | |
2287 | ||
2288 | /* Any allowed, online CPU? */ | |
2289 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2290 | if (dest_cpu < nr_cpu_ids) | |
2291 | return dest_cpu; | |
2292 | ||
2293 | /* No more Mr. Nice Guy. */ | |
897f0b3c | 2294 | if (unlikely(dest_cpu >= nr_cpu_ids)) { |
9084bb82 | 2295 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
5da9a0fb PZ |
2296 | /* |
2297 | * Don't tell them about moving exiting tasks or | |
2298 | * kernel threads (both mm NULL), since they never | |
2299 | * leave kernel. | |
2300 | */ | |
2301 | if (p->mm && printk_ratelimit()) { | |
2302 | printk(KERN_INFO "process %d (%s) no " | |
2303 | "longer affine to cpu%d\n", | |
2304 | task_pid_nr(p), p->comm, cpu); | |
2305 | } | |
2306 | } | |
2307 | ||
2308 | return dest_cpu; | |
2309 | } | |
2310 | ||
e2912009 | 2311 | /* |
30da688e | 2312 | * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable. |
e2912009 | 2313 | */ |
970b13ba | 2314 | static inline |
0017d735 | 2315 | int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 2316 | { |
0017d735 | 2317 | int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags); |
e2912009 PZ |
2318 | |
2319 | /* | |
2320 | * In order not to call set_task_cpu() on a blocking task we need | |
2321 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2322 | * cpu. | |
2323 | * | |
2324 | * Since this is common to all placement strategies, this lives here. | |
2325 | * | |
2326 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2327 | * not worry about this generic constraint ] | |
2328 | */ | |
2329 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2330 | !cpu_online(cpu))) |
5da9a0fb | 2331 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2332 | |
2333 | return cpu; | |
970b13ba PZ |
2334 | } |
2335 | #endif | |
2336 | ||
1da177e4 LT |
2337 | /*** |
2338 | * try_to_wake_up - wake up a thread | |
2339 | * @p: the to-be-woken-up thread | |
2340 | * @state: the mask of task states that can be woken | |
2341 | * @sync: do a synchronous wakeup? | |
2342 | * | |
2343 | * Put it on the run-queue if it's not already there. The "current" | |
2344 | * thread is always on the run-queue (except when the actual | |
2345 | * re-schedule is in progress), and as such you're allowed to do | |
2346 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2347 | * runnable without the overhead of this. | |
2348 | * | |
2349 | * returns failure only if the task is already active. | |
2350 | */ | |
7d478721 PZ |
2351 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2352 | int wake_flags) | |
1da177e4 | 2353 | { |
cc367732 | 2354 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 | 2355 | unsigned long flags; |
ab3b3aa5 | 2356 | struct rq *rq; |
1da177e4 | 2357 | |
e9c84311 | 2358 | this_cpu = get_cpu(); |
2398f2c6 | 2359 | |
04e2f174 | 2360 | smp_wmb(); |
ab3b3aa5 | 2361 | rq = task_rq_lock(p, &flags); |
e9c84311 | 2362 | if (!(p->state & state)) |
1da177e4 LT |
2363 | goto out; |
2364 | ||
dd41f596 | 2365 | if (p->se.on_rq) |
1da177e4 LT |
2366 | goto out_running; |
2367 | ||
2368 | cpu = task_cpu(p); | |
cc367732 | 2369 | orig_cpu = cpu; |
1da177e4 LT |
2370 | |
2371 | #ifdef CONFIG_SMP | |
2372 | if (unlikely(task_running(rq, p))) | |
2373 | goto out_activate; | |
2374 | ||
e9c84311 PZ |
2375 | /* |
2376 | * In order to handle concurrent wakeups and release the rq->lock | |
2377 | * we put the task in TASK_WAKING state. | |
eb24073b IM |
2378 | * |
2379 | * First fix up the nr_uninterruptible count: | |
e9c84311 | 2380 | */ |
cc87f76a PZ |
2381 | if (task_contributes_to_load(p)) { |
2382 | if (likely(cpu_online(orig_cpu))) | |
2383 | rq->nr_uninterruptible--; | |
2384 | else | |
2385 | this_rq()->nr_uninterruptible--; | |
2386 | } | |
e9c84311 | 2387 | p->state = TASK_WAKING; |
efbbd05a PZ |
2388 | |
2389 | if (p->sched_class->task_waking) | |
2390 | p->sched_class->task_waking(rq, p); | |
2391 | ||
0017d735 PZ |
2392 | cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); |
2393 | if (cpu != orig_cpu) | |
5d2f5a61 | 2394 | set_task_cpu(p, cpu); |
0017d735 | 2395 | __task_rq_unlock(rq); |
ab19cb23 | 2396 | |
0970d299 PZ |
2397 | rq = cpu_rq(cpu); |
2398 | raw_spin_lock(&rq->lock); | |
f5dc3753 | 2399 | |
0970d299 PZ |
2400 | /* |
2401 | * We migrated the task without holding either rq->lock, however | |
2402 | * since the task is not on the task list itself, nobody else | |
2403 | * will try and migrate the task, hence the rq should match the | |
2404 | * cpu we just moved it to. | |
2405 | */ | |
2406 | WARN_ON(task_cpu(p) != cpu); | |
e9c84311 | 2407 | WARN_ON(p->state != TASK_WAKING); |
1da177e4 | 2408 | |
e7693a36 GH |
2409 | #ifdef CONFIG_SCHEDSTATS |
2410 | schedstat_inc(rq, ttwu_count); | |
2411 | if (cpu == this_cpu) | |
2412 | schedstat_inc(rq, ttwu_local); | |
2413 | else { | |
2414 | struct sched_domain *sd; | |
2415 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2416 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2417 | schedstat_inc(sd, ttwu_wake_remote); |
2418 | break; | |
2419 | } | |
2420 | } | |
2421 | } | |
6d6bc0ad | 2422 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2423 | |
1da177e4 LT |
2424 | out_activate: |
2425 | #endif /* CONFIG_SMP */ | |
41acab88 | 2426 | schedstat_inc(p, se.statistics.nr_wakeups); |
7d478721 | 2427 | if (wake_flags & WF_SYNC) |
41acab88 | 2428 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
cc367732 | 2429 | if (orig_cpu != cpu) |
41acab88 | 2430 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); |
cc367732 | 2431 | if (cpu == this_cpu) |
41acab88 | 2432 | schedstat_inc(p, se.statistics.nr_wakeups_local); |
cc367732 | 2433 | else |
41acab88 | 2434 | schedstat_inc(p, se.statistics.nr_wakeups_remote); |
dd41f596 | 2435 | activate_task(rq, p, 1); |
1da177e4 LT |
2436 | success = 1; |
2437 | ||
2438 | out_running: | |
468a15bb | 2439 | trace_sched_wakeup(rq, p, success); |
7d478721 | 2440 | check_preempt_curr(rq, p, wake_flags); |
4ae7d5ce | 2441 | |
1da177e4 | 2442 | p->state = TASK_RUNNING; |
9a897c5a | 2443 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2444 | if (p->sched_class->task_woken) |
2445 | p->sched_class->task_woken(rq, p); | |
eae0c9df MG |
2446 | |
2447 | if (unlikely(rq->idle_stamp)) { | |
2448 | u64 delta = rq->clock - rq->idle_stamp; | |
2449 | u64 max = 2*sysctl_sched_migration_cost; | |
2450 | ||
2451 | if (delta > max) | |
2452 | rq->avg_idle = max; | |
2453 | else | |
2454 | update_avg(&rq->avg_idle, delta); | |
2455 | rq->idle_stamp = 0; | |
2456 | } | |
9a897c5a | 2457 | #endif |
1da177e4 LT |
2458 | out: |
2459 | task_rq_unlock(rq, &flags); | |
e9c84311 | 2460 | put_cpu(); |
1da177e4 LT |
2461 | |
2462 | return success; | |
2463 | } | |
2464 | ||
50fa610a DH |
2465 | /** |
2466 | * wake_up_process - Wake up a specific process | |
2467 | * @p: The process to be woken up. | |
2468 | * | |
2469 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2470 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2471 | * running. | |
2472 | * | |
2473 | * It may be assumed that this function implies a write memory barrier before | |
2474 | * changing the task state if and only if any tasks are woken up. | |
2475 | */ | |
7ad5b3a5 | 2476 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2477 | { |
d9514f6c | 2478 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2479 | } |
1da177e4 LT |
2480 | EXPORT_SYMBOL(wake_up_process); |
2481 | ||
7ad5b3a5 | 2482 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2483 | { |
2484 | return try_to_wake_up(p, state, 0); | |
2485 | } | |
2486 | ||
1da177e4 LT |
2487 | /* |
2488 | * Perform scheduler related setup for a newly forked process p. | |
2489 | * p is forked by current. | |
dd41f596 IM |
2490 | * |
2491 | * __sched_fork() is basic setup used by init_idle() too: | |
2492 | */ | |
2493 | static void __sched_fork(struct task_struct *p) | |
2494 | { | |
dd41f596 IM |
2495 | p->se.exec_start = 0; |
2496 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2497 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2498 | p->se.nr_migrations = 0; |
6cfb0d5d IM |
2499 | |
2500 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 2501 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 2502 | #endif |
476d139c | 2503 | |
fa717060 | 2504 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2505 | p->se.on_rq = 0; |
4a55bd5e | 2506 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2507 | |
e107be36 AK |
2508 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2509 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2510 | #endif | |
dd41f596 IM |
2511 | } |
2512 | ||
2513 | /* | |
2514 | * fork()/clone()-time setup: | |
2515 | */ | |
2516 | void sched_fork(struct task_struct *p, int clone_flags) | |
2517 | { | |
2518 | int cpu = get_cpu(); | |
2519 | ||
2520 | __sched_fork(p); | |
06b83b5f | 2521 | /* |
0017d735 | 2522 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
2523 | * nobody will actually run it, and a signal or other external |
2524 | * event cannot wake it up and insert it on the runqueue either. | |
2525 | */ | |
0017d735 | 2526 | p->state = TASK_RUNNING; |
dd41f596 | 2527 | |
b9dc29e7 MG |
2528 | /* |
2529 | * Revert to default priority/policy on fork if requested. | |
2530 | */ | |
2531 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2532 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2533 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2534 | p->normal_prio = p->static_prio; |
2535 | } | |
b9dc29e7 | 2536 | |
6c697bdf MG |
2537 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2538 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2539 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2540 | set_load_weight(p); |
2541 | } | |
2542 | ||
b9dc29e7 MG |
2543 | /* |
2544 | * We don't need the reset flag anymore after the fork. It has | |
2545 | * fulfilled its duty: | |
2546 | */ | |
2547 | p->sched_reset_on_fork = 0; | |
2548 | } | |
ca94c442 | 2549 | |
f83f9ac2 PW |
2550 | /* |
2551 | * Make sure we do not leak PI boosting priority to the child. | |
2552 | */ | |
2553 | p->prio = current->normal_prio; | |
2554 | ||
2ddbf952 HS |
2555 | if (!rt_prio(p->prio)) |
2556 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2557 | |
cd29fe6f PZ |
2558 | if (p->sched_class->task_fork) |
2559 | p->sched_class->task_fork(p); | |
2560 | ||
5f3edc1b PZ |
2561 | set_task_cpu(p, cpu); |
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; |
c890692b | 2590 | int cpu __maybe_unused = get_cpu(); |
fabf318e PZ |
2591 | |
2592 | #ifdef CONFIG_SMP | |
0017d735 PZ |
2593 | rq = task_rq_lock(p, &flags); |
2594 | p->state = TASK_WAKING; | |
2595 | ||
fabf318e PZ |
2596 | /* |
2597 | * Fork balancing, do it here and not earlier because: | |
2598 | * - cpus_allowed can change in the fork path | |
2599 | * - any previously selected cpu might disappear through hotplug | |
2600 | * | |
0017d735 PZ |
2601 | * We set TASK_WAKING so that select_task_rq() can drop rq->lock |
2602 | * without people poking at ->cpus_allowed. | |
fabf318e | 2603 | */ |
0017d735 | 2604 | cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0); |
fabf318e | 2605 | set_task_cpu(p, cpu); |
0970d299 | 2606 | |
06b83b5f | 2607 | p->state = TASK_RUNNING; |
0017d735 PZ |
2608 | task_rq_unlock(rq, &flags); |
2609 | #endif | |
2610 | ||
2611 | rq = task_rq_lock(p, &flags); | |
cd29fe6f | 2612 | activate_task(rq, p, 0); |
c71dd42d | 2613 | trace_sched_wakeup_new(rq, p, 1); |
a7558e01 | 2614 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2615 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2616 | if (p->sched_class->task_woken) |
2617 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2618 | #endif |
dd41f596 | 2619 | task_rq_unlock(rq, &flags); |
fabf318e | 2620 | put_cpu(); |
1da177e4 LT |
2621 | } |
2622 | ||
e107be36 AK |
2623 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2624 | ||
2625 | /** | |
80dd99b3 | 2626 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2627 | * @notifier: notifier struct to register |
e107be36 AK |
2628 | */ |
2629 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2630 | { | |
2631 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2632 | } | |
2633 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2634 | ||
2635 | /** | |
2636 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2637 | * @notifier: notifier struct to unregister |
e107be36 AK |
2638 | * |
2639 | * This is safe to call from within a preemption notifier. | |
2640 | */ | |
2641 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2642 | { | |
2643 | hlist_del(¬ifier->link); | |
2644 | } | |
2645 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2646 | ||
2647 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2648 | { | |
2649 | struct preempt_notifier *notifier; | |
2650 | struct hlist_node *node; | |
2651 | ||
2652 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2653 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2654 | } | |
2655 | ||
2656 | static void | |
2657 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2658 | struct task_struct *next) | |
2659 | { | |
2660 | struct preempt_notifier *notifier; | |
2661 | struct hlist_node *node; | |
2662 | ||
2663 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2664 | notifier->ops->sched_out(notifier, next); | |
2665 | } | |
2666 | ||
6d6bc0ad | 2667 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2668 | |
2669 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2670 | { | |
2671 | } | |
2672 | ||
2673 | static void | |
2674 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2675 | struct task_struct *next) | |
2676 | { | |
2677 | } | |
2678 | ||
6d6bc0ad | 2679 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2680 | |
4866cde0 NP |
2681 | /** |
2682 | * prepare_task_switch - prepare to switch tasks | |
2683 | * @rq: the runqueue preparing to switch | |
421cee29 | 2684 | * @prev: the current task that is being switched out |
4866cde0 NP |
2685 | * @next: the task we are going to switch to. |
2686 | * | |
2687 | * This is called with the rq lock held and interrupts off. It must | |
2688 | * be paired with a subsequent finish_task_switch after the context | |
2689 | * switch. | |
2690 | * | |
2691 | * prepare_task_switch sets up locking and calls architecture specific | |
2692 | * hooks. | |
2693 | */ | |
e107be36 AK |
2694 | static inline void |
2695 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2696 | struct task_struct *next) | |
4866cde0 | 2697 | { |
e107be36 | 2698 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2699 | prepare_lock_switch(rq, next); |
2700 | prepare_arch_switch(next); | |
2701 | } | |
2702 | ||
1da177e4 LT |
2703 | /** |
2704 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2705 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2706 | * @prev: the thread we just switched away from. |
2707 | * | |
4866cde0 NP |
2708 | * finish_task_switch must be called after the context switch, paired |
2709 | * with a prepare_task_switch call before the context switch. | |
2710 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2711 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2712 | * |
2713 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2714 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2715 | * with the lock held can cause deadlocks; see schedule() for |
2716 | * details.) | |
2717 | */ | |
a9957449 | 2718 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2719 | __releases(rq->lock) |
2720 | { | |
1da177e4 | 2721 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2722 | long prev_state; |
1da177e4 LT |
2723 | |
2724 | rq->prev_mm = NULL; | |
2725 | ||
2726 | /* | |
2727 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2728 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2729 | * schedule one last time. The schedule call will never return, and |
2730 | * the scheduled task must drop that reference. | |
c394cc9f | 2731 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2732 | * still held, otherwise prev could be scheduled on another cpu, die |
2733 | * there before we look at prev->state, and then the reference would | |
2734 | * be dropped twice. | |
2735 | * Manfred Spraul <manfred@colorfullife.com> | |
2736 | */ | |
55a101f8 | 2737 | prev_state = prev->state; |
4866cde0 | 2738 | finish_arch_switch(prev); |
8381f65d JI |
2739 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2740 | local_irq_disable(); | |
2741 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
49f47433 | 2742 | perf_event_task_sched_in(current); |
8381f65d JI |
2743 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2744 | local_irq_enable(); | |
2745 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 2746 | finish_lock_switch(rq, prev); |
e8fa1362 | 2747 | |
e107be36 | 2748 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2749 | if (mm) |
2750 | mmdrop(mm); | |
c394cc9f | 2751 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2752 | /* |
2753 | * Remove function-return probe instances associated with this | |
2754 | * task and put them back on the free list. | |
9761eea8 | 2755 | */ |
c6fd91f0 | 2756 | kprobe_flush_task(prev); |
1da177e4 | 2757 | put_task_struct(prev); |
c6fd91f0 | 2758 | } |
1da177e4 LT |
2759 | } |
2760 | ||
3f029d3c GH |
2761 | #ifdef CONFIG_SMP |
2762 | ||
2763 | /* assumes rq->lock is held */ | |
2764 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2765 | { | |
2766 | if (prev->sched_class->pre_schedule) | |
2767 | prev->sched_class->pre_schedule(rq, prev); | |
2768 | } | |
2769 | ||
2770 | /* rq->lock is NOT held, but preemption is disabled */ | |
2771 | static inline void post_schedule(struct rq *rq) | |
2772 | { | |
2773 | if (rq->post_schedule) { | |
2774 | unsigned long flags; | |
2775 | ||
05fa785c | 2776 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2777 | if (rq->curr->sched_class->post_schedule) |
2778 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2779 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2780 | |
2781 | rq->post_schedule = 0; | |
2782 | } | |
2783 | } | |
2784 | ||
2785 | #else | |
da19ab51 | 2786 | |
3f029d3c GH |
2787 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2788 | { | |
2789 | } | |
2790 | ||
2791 | static inline void post_schedule(struct rq *rq) | |
2792 | { | |
1da177e4 LT |
2793 | } |
2794 | ||
3f029d3c GH |
2795 | #endif |
2796 | ||
1da177e4 LT |
2797 | /** |
2798 | * schedule_tail - first thing a freshly forked thread must call. | |
2799 | * @prev: the thread we just switched away from. | |
2800 | */ | |
36c8b586 | 2801 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2802 | __releases(rq->lock) |
2803 | { | |
70b97a7f IM |
2804 | struct rq *rq = this_rq(); |
2805 | ||
4866cde0 | 2806 | finish_task_switch(rq, prev); |
da19ab51 | 2807 | |
3f029d3c GH |
2808 | /* |
2809 | * FIXME: do we need to worry about rq being invalidated by the | |
2810 | * task_switch? | |
2811 | */ | |
2812 | post_schedule(rq); | |
70b97a7f | 2813 | |
4866cde0 NP |
2814 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2815 | /* In this case, finish_task_switch does not reenable preemption */ | |
2816 | preempt_enable(); | |
2817 | #endif | |
1da177e4 | 2818 | if (current->set_child_tid) |
b488893a | 2819 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2820 | } |
2821 | ||
2822 | /* | |
2823 | * context_switch - switch to the new MM and the new | |
2824 | * thread's register state. | |
2825 | */ | |
dd41f596 | 2826 | static inline void |
70b97a7f | 2827 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2828 | struct task_struct *next) |
1da177e4 | 2829 | { |
dd41f596 | 2830 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2831 | |
e107be36 | 2832 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2833 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2834 | mm = next->mm; |
2835 | oldmm = prev->active_mm; | |
9226d125 ZA |
2836 | /* |
2837 | * For paravirt, this is coupled with an exit in switch_to to | |
2838 | * combine the page table reload and the switch backend into | |
2839 | * one hypercall. | |
2840 | */ | |
224101ed | 2841 | arch_start_context_switch(prev); |
9226d125 | 2842 | |
710390d9 | 2843 | if (likely(!mm)) { |
1da177e4 LT |
2844 | next->active_mm = oldmm; |
2845 | atomic_inc(&oldmm->mm_count); | |
2846 | enter_lazy_tlb(oldmm, next); | |
2847 | } else | |
2848 | switch_mm(oldmm, mm, next); | |
2849 | ||
710390d9 | 2850 | if (likely(!prev->mm)) { |
1da177e4 | 2851 | prev->active_mm = NULL; |
1da177e4 LT |
2852 | rq->prev_mm = oldmm; |
2853 | } | |
3a5f5e48 IM |
2854 | /* |
2855 | * Since the runqueue lock will be released by the next | |
2856 | * task (which is an invalid locking op but in the case | |
2857 | * of the scheduler it's an obvious special-case), so we | |
2858 | * do an early lockdep release here: | |
2859 | */ | |
2860 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2861 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2862 | #endif |
1da177e4 LT |
2863 | |
2864 | /* Here we just switch the register state and the stack. */ | |
2865 | switch_to(prev, next, prev); | |
2866 | ||
dd41f596 IM |
2867 | barrier(); |
2868 | /* | |
2869 | * this_rq must be evaluated again because prev may have moved | |
2870 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2871 | * frame will be invalid. | |
2872 | */ | |
2873 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2874 | } |
2875 | ||
2876 | /* | |
2877 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2878 | * | |
2879 | * externally visible scheduler statistics: current number of runnable | |
2880 | * threads, current number of uninterruptible-sleeping threads, total | |
2881 | * number of context switches performed since bootup. | |
2882 | */ | |
2883 | unsigned long nr_running(void) | |
2884 | { | |
2885 | unsigned long i, sum = 0; | |
2886 | ||
2887 | for_each_online_cpu(i) | |
2888 | sum += cpu_rq(i)->nr_running; | |
2889 | ||
2890 | return sum; | |
f711f609 | 2891 | } |
1da177e4 LT |
2892 | |
2893 | unsigned long nr_uninterruptible(void) | |
f711f609 | 2894 | { |
1da177e4 | 2895 | unsigned long i, sum = 0; |
f711f609 | 2896 | |
0a945022 | 2897 | for_each_possible_cpu(i) |
1da177e4 | 2898 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
2899 | |
2900 | /* | |
1da177e4 LT |
2901 | * Since we read the counters lockless, it might be slightly |
2902 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 2903 | */ |
1da177e4 LT |
2904 | if (unlikely((long)sum < 0)) |
2905 | sum = 0; | |
f711f609 | 2906 | |
1da177e4 | 2907 | return sum; |
f711f609 | 2908 | } |
f711f609 | 2909 | |
1da177e4 | 2910 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2911 | { |
cc94abfc SR |
2912 | int i; |
2913 | unsigned long long sum = 0; | |
46cb4b7c | 2914 | |
0a945022 | 2915 | for_each_possible_cpu(i) |
1da177e4 | 2916 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2917 | |
1da177e4 LT |
2918 | return sum; |
2919 | } | |
483b4ee6 | 2920 | |
1da177e4 LT |
2921 | unsigned long nr_iowait(void) |
2922 | { | |
2923 | unsigned long i, sum = 0; | |
483b4ee6 | 2924 | |
0a945022 | 2925 | for_each_possible_cpu(i) |
1da177e4 | 2926 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2927 | |
1da177e4 LT |
2928 | return sum; |
2929 | } | |
483b4ee6 | 2930 | |
69d25870 AV |
2931 | unsigned long nr_iowait_cpu(void) |
2932 | { | |
2933 | struct rq *this = this_rq(); | |
2934 | return atomic_read(&this->nr_iowait); | |
2935 | } | |
46cb4b7c | 2936 | |
69d25870 AV |
2937 | unsigned long this_cpu_load(void) |
2938 | { | |
2939 | struct rq *this = this_rq(); | |
2940 | return this->cpu_load[0]; | |
2941 | } | |
e790fb0b | 2942 | |
46cb4b7c | 2943 | |
dce48a84 TG |
2944 | /* Variables and functions for calc_load */ |
2945 | static atomic_long_t calc_load_tasks; | |
2946 | static unsigned long calc_load_update; | |
2947 | unsigned long avenrun[3]; | |
2948 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 2949 | |
2d02494f TG |
2950 | /** |
2951 | * get_avenrun - get the load average array | |
2952 | * @loads: pointer to dest load array | |
2953 | * @offset: offset to add | |
2954 | * @shift: shift count to shift the result left | |
2955 | * | |
2956 | * These values are estimates at best, so no need for locking. | |
2957 | */ | |
2958 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
2959 | { | |
2960 | loads[0] = (avenrun[0] + offset) << shift; | |
2961 | loads[1] = (avenrun[1] + offset) << shift; | |
2962 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 2963 | } |
46cb4b7c | 2964 | |
dce48a84 TG |
2965 | static unsigned long |
2966 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 2967 | { |
dce48a84 TG |
2968 | load *= exp; |
2969 | load += active * (FIXED_1 - exp); | |
2970 | return load >> FSHIFT; | |
2971 | } | |
46cb4b7c SS |
2972 | |
2973 | /* | |
dce48a84 TG |
2974 | * calc_load - update the avenrun load estimates 10 ticks after the |
2975 | * CPUs have updated calc_load_tasks. | |
7835b98b | 2976 | */ |
dce48a84 | 2977 | void calc_global_load(void) |
7835b98b | 2978 | { |
dce48a84 TG |
2979 | unsigned long upd = calc_load_update + 10; |
2980 | long active; | |
1da177e4 | 2981 | |
dce48a84 TG |
2982 | if (time_before(jiffies, upd)) |
2983 | return; | |
1da177e4 | 2984 | |
dce48a84 TG |
2985 | active = atomic_long_read(&calc_load_tasks); |
2986 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 2987 | |
dce48a84 TG |
2988 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
2989 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
2990 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 2991 | |
dce48a84 TG |
2992 | calc_load_update += LOAD_FREQ; |
2993 | } | |
1da177e4 | 2994 | |
dce48a84 TG |
2995 | /* |
2996 | * Either called from update_cpu_load() or from a cpu going idle | |
2997 | */ | |
2998 | static void calc_load_account_active(struct rq *this_rq) | |
2999 | { | |
3000 | long nr_active, delta; | |
08c183f3 | 3001 | |
dce48a84 TG |
3002 | nr_active = this_rq->nr_running; |
3003 | nr_active += (long) this_rq->nr_uninterruptible; | |
783609c6 | 3004 | |
dce48a84 TG |
3005 | if (nr_active != this_rq->calc_load_active) { |
3006 | delta = nr_active - this_rq->calc_load_active; | |
3007 | this_rq->calc_load_active = nr_active; | |
3008 | atomic_long_add(delta, &calc_load_tasks); | |
1da177e4 | 3009 | } |
46cb4b7c SS |
3010 | } |
3011 | ||
3012 | /* | |
dd41f596 IM |
3013 | * Update rq->cpu_load[] statistics. This function is usually called every |
3014 | * scheduler tick (TICK_NSEC). | |
46cb4b7c | 3015 | */ |
dd41f596 | 3016 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3017 | { |
495eca49 | 3018 | unsigned long this_load = this_rq->load.weight; |
dd41f596 | 3019 | int i, scale; |
46cb4b7c | 3020 | |
dd41f596 | 3021 | this_rq->nr_load_updates++; |
46cb4b7c | 3022 | |
dd41f596 IM |
3023 | /* Update our load: */ |
3024 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
3025 | unsigned long old_load, new_load; | |
7d1e6a9b | 3026 | |
dd41f596 | 3027 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3028 | |
dd41f596 IM |
3029 | old_load = this_rq->cpu_load[i]; |
3030 | new_load = this_load; | |
a25707f3 IM |
3031 | /* |
3032 | * Round up the averaging division if load is increasing. This | |
3033 | * prevents us from getting stuck on 9 if the load is 10, for | |
3034 | * example. | |
3035 | */ | |
3036 | if (new_load > old_load) | |
3037 | new_load += scale-1; | |
dd41f596 IM |
3038 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
3039 | } | |
46cb4b7c | 3040 | |
dce48a84 TG |
3041 | if (time_after_eq(jiffies, this_rq->calc_load_update)) { |
3042 | this_rq->calc_load_update += LOAD_FREQ; | |
3043 | calc_load_account_active(this_rq); | |
46cb4b7c | 3044 | } |
46cb4b7c SS |
3045 | } |
3046 | ||
dd41f596 | 3047 | #ifdef CONFIG_SMP |
8a0be9ef | 3048 | |
46cb4b7c | 3049 | /* |
38022906 PZ |
3050 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3051 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3052 | */ |
38022906 | 3053 | void sched_exec(void) |
46cb4b7c | 3054 | { |
38022906 | 3055 | struct task_struct *p = current; |
70b97a7f | 3056 | struct migration_req req; |
1da177e4 | 3057 | unsigned long flags; |
70b97a7f | 3058 | struct rq *rq; |
0017d735 | 3059 | int dest_cpu; |
46cb4b7c | 3060 | |
1da177e4 | 3061 | rq = task_rq_lock(p, &flags); |
0017d735 PZ |
3062 | dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0); |
3063 | if (dest_cpu == smp_processor_id()) | |
3064 | goto unlock; | |
3065 | ||
46cb4b7c | 3066 | /* |
38022906 | 3067 | * select_task_rq() can race against ->cpus_allowed |
46cb4b7c | 3068 | */ |
30da688e ON |
3069 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) && |
3070 | likely(cpu_active(dest_cpu)) && | |
3071 | migrate_task(p, dest_cpu, &req)) { | |
1da177e4 LT |
3072 | /* Need to wait for migration thread (might exit: take ref). */ |
3073 | struct task_struct *mt = rq->migration_thread; | |
dd41f596 | 3074 | |
1da177e4 LT |
3075 | get_task_struct(mt); |
3076 | task_rq_unlock(rq, &flags); | |
3077 | wake_up_process(mt); | |
3078 | put_task_struct(mt); | |
3079 | wait_for_completion(&req.done); | |
dd41f596 | 3080 | |
1da177e4 LT |
3081 | return; |
3082 | } | |
0017d735 | 3083 | unlock: |
1da177e4 | 3084 | task_rq_unlock(rq, &flags); |
1da177e4 | 3085 | } |
dd41f596 | 3086 | |
1da177e4 LT |
3087 | #endif |
3088 | ||
1da177e4 LT |
3089 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3090 | ||
3091 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3092 | ||
3093 | /* | |
c5f8d995 | 3094 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3095 | * @p in case that task is currently running. |
c5f8d995 HS |
3096 | * |
3097 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3098 | */ |
c5f8d995 HS |
3099 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3100 | { | |
3101 | u64 ns = 0; | |
3102 | ||
3103 | if (task_current(rq, p)) { | |
3104 | update_rq_clock(rq); | |
3105 | ns = rq->clock - p->se.exec_start; | |
3106 | if ((s64)ns < 0) | |
3107 | ns = 0; | |
3108 | } | |
3109 | ||
3110 | return ns; | |
3111 | } | |
3112 | ||
bb34d92f | 3113 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3114 | { |
1da177e4 | 3115 | unsigned long flags; |
41b86e9c | 3116 | struct rq *rq; |
bb34d92f | 3117 | u64 ns = 0; |
48f24c4d | 3118 | |
41b86e9c | 3119 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
3120 | ns = do_task_delta_exec(p, rq); |
3121 | task_rq_unlock(rq, &flags); | |
1508487e | 3122 | |
c5f8d995 HS |
3123 | return ns; |
3124 | } | |
f06febc9 | 3125 | |
c5f8d995 HS |
3126 | /* |
3127 | * Return accounted runtime for the task. | |
3128 | * In case the task is currently running, return the runtime plus current's | |
3129 | * pending runtime that have not been accounted yet. | |
3130 | */ | |
3131 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3132 | { | |
3133 | unsigned long flags; | |
3134 | struct rq *rq; | |
3135 | u64 ns = 0; | |
3136 | ||
3137 | rq = task_rq_lock(p, &flags); | |
3138 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
3139 | task_rq_unlock(rq, &flags); | |
3140 | ||
3141 | return ns; | |
3142 | } | |
48f24c4d | 3143 | |
c5f8d995 HS |
3144 | /* |
3145 | * Return sum_exec_runtime for the thread group. | |
3146 | * In case the task is currently running, return the sum plus current's | |
3147 | * pending runtime that have not been accounted yet. | |
3148 | * | |
3149 | * Note that the thread group might have other running tasks as well, | |
3150 | * so the return value not includes other pending runtime that other | |
3151 | * running tasks might have. | |
3152 | */ | |
3153 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
3154 | { | |
3155 | struct task_cputime totals; | |
3156 | unsigned long flags; | |
3157 | struct rq *rq; | |
3158 | u64 ns; | |
3159 | ||
3160 | rq = task_rq_lock(p, &flags); | |
3161 | thread_group_cputime(p, &totals); | |
3162 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 3163 | task_rq_unlock(rq, &flags); |
48f24c4d | 3164 | |
1da177e4 LT |
3165 | return ns; |
3166 | } | |
3167 | ||
1da177e4 LT |
3168 | /* |
3169 | * Account user cpu time to a process. | |
3170 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3171 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3172 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3173 | */ |
457533a7 MS |
3174 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3175 | cputime_t cputime_scaled) | |
1da177e4 LT |
3176 | { |
3177 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3178 | cputime64_t tmp; | |
3179 | ||
457533a7 | 3180 | /* Add user time to process. */ |
1da177e4 | 3181 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3182 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3183 | account_group_user_time(p, cputime); |
1da177e4 LT |
3184 | |
3185 | /* Add user time to cpustat. */ | |
3186 | tmp = cputime_to_cputime64(cputime); | |
3187 | if (TASK_NICE(p) > 0) | |
3188 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3189 | else | |
3190 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
3191 | |
3192 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3193 | /* Account for user time used */ |
3194 | acct_update_integrals(p); | |
1da177e4 LT |
3195 | } |
3196 | ||
94886b84 LV |
3197 | /* |
3198 | * Account guest cpu time to a process. | |
3199 | * @p: the process that the cpu time gets accounted to | |
3200 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3201 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3202 | */ |
457533a7 MS |
3203 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3204 | cputime_t cputime_scaled) | |
94886b84 LV |
3205 | { |
3206 | cputime64_t tmp; | |
3207 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3208 | ||
3209 | tmp = cputime_to_cputime64(cputime); | |
3210 | ||
457533a7 | 3211 | /* Add guest time to process. */ |
94886b84 | 3212 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3213 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3214 | account_group_user_time(p, cputime); |
94886b84 LV |
3215 | p->gtime = cputime_add(p->gtime, cputime); |
3216 | ||
457533a7 | 3217 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
3218 | if (TASK_NICE(p) > 0) { |
3219 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3220 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
3221 | } else { | |
3222 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
3223 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
3224 | } | |
94886b84 LV |
3225 | } |
3226 | ||
1da177e4 LT |
3227 | /* |
3228 | * Account system cpu time to a process. | |
3229 | * @p: the process that the cpu time gets accounted to | |
3230 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3231 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3232 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3233 | */ |
3234 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3235 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3236 | { |
3237 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
3238 | cputime64_t tmp; |
3239 | ||
983ed7a6 | 3240 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3241 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3242 | return; |
3243 | } | |
94886b84 | 3244 | |
457533a7 | 3245 | /* Add system time to process. */ |
1da177e4 | 3246 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 3247 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 3248 | account_group_system_time(p, cputime); |
1da177e4 LT |
3249 | |
3250 | /* Add system time to cpustat. */ | |
3251 | tmp = cputime_to_cputime64(cputime); | |
3252 | if (hardirq_count() - hardirq_offset) | |
3253 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
3254 | else if (softirq_count()) | |
3255 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 3256 | else |
79741dd3 MS |
3257 | cpustat->system = cputime64_add(cpustat->system, tmp); |
3258 | ||
ef12fefa BR |
3259 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
3260 | ||
1da177e4 LT |
3261 | /* Account for system time used */ |
3262 | acct_update_integrals(p); | |
1da177e4 LT |
3263 | } |
3264 | ||
c66f08be | 3265 | /* |
1da177e4 | 3266 | * Account for involuntary wait time. |
1da177e4 | 3267 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 3268 | */ |
79741dd3 | 3269 | void account_steal_time(cputime_t cputime) |
c66f08be | 3270 | { |
79741dd3 MS |
3271 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3272 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
3273 | ||
3274 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
3275 | } |
3276 | ||
1da177e4 | 3277 | /* |
79741dd3 MS |
3278 | * Account for idle time. |
3279 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3280 | */ |
79741dd3 | 3281 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3282 | { |
3283 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 3284 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 3285 | struct rq *rq = this_rq(); |
1da177e4 | 3286 | |
79741dd3 MS |
3287 | if (atomic_read(&rq->nr_iowait) > 0) |
3288 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
3289 | else | |
3290 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
3291 | } |
3292 | ||
79741dd3 MS |
3293 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
3294 | ||
3295 | /* | |
3296 | * Account a single tick of cpu time. | |
3297 | * @p: the process that the cpu time gets accounted to | |
3298 | * @user_tick: indicates if the tick is a user or a system tick | |
3299 | */ | |
3300 | void account_process_tick(struct task_struct *p, int user_tick) | |
3301 | { | |
a42548a1 | 3302 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
3303 | struct rq *rq = this_rq(); |
3304 | ||
3305 | if (user_tick) | |
a42548a1 | 3306 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 3307 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 3308 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
3309 | one_jiffy_scaled); |
3310 | else | |
a42548a1 | 3311 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
3312 | } |
3313 | ||
3314 | /* | |
3315 | * Account multiple ticks of steal time. | |
3316 | * @p: the process from which the cpu time has been stolen | |
3317 | * @ticks: number of stolen ticks | |
3318 | */ | |
3319 | void account_steal_ticks(unsigned long ticks) | |
3320 | { | |
3321 | account_steal_time(jiffies_to_cputime(ticks)); | |
3322 | } | |
3323 | ||
3324 | /* | |
3325 | * Account multiple ticks of idle time. | |
3326 | * @ticks: number of stolen ticks | |
3327 | */ | |
3328 | void account_idle_ticks(unsigned long ticks) | |
3329 | { | |
3330 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
3331 | } |
3332 | ||
79741dd3 MS |
3333 | #endif |
3334 | ||
49048622 BS |
3335 | /* |
3336 | * Use precise platform statistics if available: | |
3337 | */ | |
3338 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 3339 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3340 | { |
d99ca3b9 HS |
3341 | *ut = p->utime; |
3342 | *st = p->stime; | |
49048622 BS |
3343 | } |
3344 | ||
0cf55e1e | 3345 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3346 | { |
0cf55e1e HS |
3347 | struct task_cputime cputime; |
3348 | ||
3349 | thread_group_cputime(p, &cputime); | |
3350 | ||
3351 | *ut = cputime.utime; | |
3352 | *st = cputime.stime; | |
49048622 BS |
3353 | } |
3354 | #else | |
761b1d26 HS |
3355 | |
3356 | #ifndef nsecs_to_cputime | |
b7b20df9 | 3357 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
3358 | #endif |
3359 | ||
d180c5bc | 3360 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3361 | { |
d99ca3b9 | 3362 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
3363 | |
3364 | /* | |
3365 | * Use CFS's precise accounting: | |
3366 | */ | |
d180c5bc | 3367 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
3368 | |
3369 | if (total) { | |
d180c5bc HS |
3370 | u64 temp; |
3371 | ||
3372 | temp = (u64)(rtime * utime); | |
49048622 | 3373 | do_div(temp, total); |
d180c5bc HS |
3374 | utime = (cputime_t)temp; |
3375 | } else | |
3376 | utime = rtime; | |
49048622 | 3377 | |
d180c5bc HS |
3378 | /* |
3379 | * Compare with previous values, to keep monotonicity: | |
3380 | */ | |
761b1d26 | 3381 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 3382 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 3383 | |
d99ca3b9 HS |
3384 | *ut = p->prev_utime; |
3385 | *st = p->prev_stime; | |
49048622 BS |
3386 | } |
3387 | ||
0cf55e1e HS |
3388 | /* |
3389 | * Must be called with siglock held. | |
3390 | */ | |
3391 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 3392 | { |
0cf55e1e HS |
3393 | struct signal_struct *sig = p->signal; |
3394 | struct task_cputime cputime; | |
3395 | cputime_t rtime, utime, total; | |
49048622 | 3396 | |
0cf55e1e | 3397 | thread_group_cputime(p, &cputime); |
49048622 | 3398 | |
0cf55e1e HS |
3399 | total = cputime_add(cputime.utime, cputime.stime); |
3400 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 3401 | |
0cf55e1e HS |
3402 | if (total) { |
3403 | u64 temp; | |
49048622 | 3404 | |
0cf55e1e HS |
3405 | temp = (u64)(rtime * cputime.utime); |
3406 | do_div(temp, total); | |
3407 | utime = (cputime_t)temp; | |
3408 | } else | |
3409 | utime = rtime; | |
3410 | ||
3411 | sig->prev_utime = max(sig->prev_utime, utime); | |
3412 | sig->prev_stime = max(sig->prev_stime, | |
3413 | cputime_sub(rtime, sig->prev_utime)); | |
3414 | ||
3415 | *ut = sig->prev_utime; | |
3416 | *st = sig->prev_stime; | |
49048622 | 3417 | } |
49048622 | 3418 | #endif |
49048622 | 3419 | |
7835b98b CL |
3420 | /* |
3421 | * This function gets called by the timer code, with HZ frequency. | |
3422 | * We call it with interrupts disabled. | |
3423 | * | |
3424 | * It also gets called by the fork code, when changing the parent's | |
3425 | * timeslices. | |
3426 | */ | |
3427 | void scheduler_tick(void) | |
3428 | { | |
7835b98b CL |
3429 | int cpu = smp_processor_id(); |
3430 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 3431 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
3432 | |
3433 | sched_clock_tick(); | |
dd41f596 | 3434 | |
05fa785c | 3435 | raw_spin_lock(&rq->lock); |
3e51f33f | 3436 | update_rq_clock(rq); |
f1a438d8 | 3437 | update_cpu_load(rq); |
fa85ae24 | 3438 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 3439 | raw_spin_unlock(&rq->lock); |
7835b98b | 3440 | |
49f47433 | 3441 | perf_event_task_tick(curr); |
e220d2dc | 3442 | |
e418e1c2 | 3443 | #ifdef CONFIG_SMP |
dd41f596 IM |
3444 | rq->idle_at_tick = idle_cpu(cpu); |
3445 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 3446 | #endif |
1da177e4 LT |
3447 | } |
3448 | ||
132380a0 | 3449 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
3450 | { |
3451 | if (in_lock_functions(addr)) { | |
3452 | addr = CALLER_ADDR2; | |
3453 | if (in_lock_functions(addr)) | |
3454 | addr = CALLER_ADDR3; | |
3455 | } | |
3456 | return addr; | |
3457 | } | |
1da177e4 | 3458 | |
7e49fcce SR |
3459 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
3460 | defined(CONFIG_PREEMPT_TRACER)) | |
3461 | ||
43627582 | 3462 | void __kprobes add_preempt_count(int val) |
1da177e4 | 3463 | { |
6cd8a4bb | 3464 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3465 | /* |
3466 | * Underflow? | |
3467 | */ | |
9a11b49a IM |
3468 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
3469 | return; | |
6cd8a4bb | 3470 | #endif |
1da177e4 | 3471 | preempt_count() += val; |
6cd8a4bb | 3472 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3473 | /* |
3474 | * Spinlock count overflowing soon? | |
3475 | */ | |
33859f7f MOS |
3476 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
3477 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
3478 | #endif |
3479 | if (preempt_count() == val) | |
3480 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3481 | } |
3482 | EXPORT_SYMBOL(add_preempt_count); | |
3483 | ||
43627582 | 3484 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 3485 | { |
6cd8a4bb | 3486 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3487 | /* |
3488 | * Underflow? | |
3489 | */ | |
01e3eb82 | 3490 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 3491 | return; |
1da177e4 LT |
3492 | /* |
3493 | * Is the spinlock portion underflowing? | |
3494 | */ | |
9a11b49a IM |
3495 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
3496 | !(preempt_count() & PREEMPT_MASK))) | |
3497 | return; | |
6cd8a4bb | 3498 | #endif |
9a11b49a | 3499 | |
6cd8a4bb SR |
3500 | if (preempt_count() == val) |
3501 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3502 | preempt_count() -= val; |
3503 | } | |
3504 | EXPORT_SYMBOL(sub_preempt_count); | |
3505 | ||
3506 | #endif | |
3507 | ||
3508 | /* | |
dd41f596 | 3509 | * Print scheduling while atomic bug: |
1da177e4 | 3510 | */ |
dd41f596 | 3511 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 3512 | { |
838225b4 SS |
3513 | struct pt_regs *regs = get_irq_regs(); |
3514 | ||
3df0fc5b PZ |
3515 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
3516 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 3517 | |
dd41f596 | 3518 | debug_show_held_locks(prev); |
e21f5b15 | 3519 | print_modules(); |
dd41f596 IM |
3520 | if (irqs_disabled()) |
3521 | print_irqtrace_events(prev); | |
838225b4 SS |
3522 | |
3523 | if (regs) | |
3524 | show_regs(regs); | |
3525 | else | |
3526 | dump_stack(); | |
dd41f596 | 3527 | } |
1da177e4 | 3528 | |
dd41f596 IM |
3529 | /* |
3530 | * Various schedule()-time debugging checks and statistics: | |
3531 | */ | |
3532 | static inline void schedule_debug(struct task_struct *prev) | |
3533 | { | |
1da177e4 | 3534 | /* |
41a2d6cf | 3535 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
3536 | * schedule() atomically, we ignore that path for now. |
3537 | * Otherwise, whine if we are scheduling when we should not be. | |
3538 | */ | |
3f33a7ce | 3539 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
3540 | __schedule_bug(prev); |
3541 | ||
1da177e4 LT |
3542 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
3543 | ||
2d72376b | 3544 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
3545 | #ifdef CONFIG_SCHEDSTATS |
3546 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
3547 | schedstat_inc(this_rq(), bkl_count); |
3548 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
3549 | } |
3550 | #endif | |
dd41f596 IM |
3551 | } |
3552 | ||
6cecd084 | 3553 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 3554 | { |
a64692a3 MG |
3555 | if (prev->se.on_rq) |
3556 | update_rq_clock(rq); | |
3557 | rq->skip_clock_update = 0; | |
6cecd084 | 3558 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
3559 | } |
3560 | ||
dd41f596 IM |
3561 | /* |
3562 | * Pick up the highest-prio task: | |
3563 | */ | |
3564 | static inline struct task_struct * | |
b67802ea | 3565 | pick_next_task(struct rq *rq) |
dd41f596 | 3566 | { |
5522d5d5 | 3567 | const struct sched_class *class; |
dd41f596 | 3568 | struct task_struct *p; |
1da177e4 LT |
3569 | |
3570 | /* | |
dd41f596 IM |
3571 | * Optimization: we know that if all tasks are in |
3572 | * the fair class we can call that function directly: | |
1da177e4 | 3573 | */ |
dd41f596 | 3574 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 3575 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
3576 | if (likely(p)) |
3577 | return p; | |
1da177e4 LT |
3578 | } |
3579 | ||
dd41f596 IM |
3580 | class = sched_class_highest; |
3581 | for ( ; ; ) { | |
fb8d4724 | 3582 | p = class->pick_next_task(rq); |
dd41f596 IM |
3583 | if (p) |
3584 | return p; | |
3585 | /* | |
3586 | * Will never be NULL as the idle class always | |
3587 | * returns a non-NULL p: | |
3588 | */ | |
3589 | class = class->next; | |
3590 | } | |
3591 | } | |
1da177e4 | 3592 | |
dd41f596 IM |
3593 | /* |
3594 | * schedule() is the main scheduler function. | |
3595 | */ | |
ff743345 | 3596 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
3597 | { |
3598 | struct task_struct *prev, *next; | |
67ca7bde | 3599 | unsigned long *switch_count; |
dd41f596 | 3600 | struct rq *rq; |
31656519 | 3601 | int cpu; |
dd41f596 | 3602 | |
ff743345 PZ |
3603 | need_resched: |
3604 | preempt_disable(); | |
dd41f596 IM |
3605 | cpu = smp_processor_id(); |
3606 | rq = cpu_rq(cpu); | |
d6714c22 | 3607 | rcu_sched_qs(cpu); |
dd41f596 IM |
3608 | prev = rq->curr; |
3609 | switch_count = &prev->nivcsw; | |
3610 | ||
3611 | release_kernel_lock(prev); | |
3612 | need_resched_nonpreemptible: | |
3613 | ||
3614 | schedule_debug(prev); | |
1da177e4 | 3615 | |
31656519 | 3616 | if (sched_feat(HRTICK)) |
f333fdc9 | 3617 | hrtick_clear(rq); |
8f4d37ec | 3618 | |
05fa785c | 3619 | raw_spin_lock_irq(&rq->lock); |
1e819950 | 3620 | clear_tsk_need_resched(prev); |
1da177e4 | 3621 | |
1da177e4 | 3622 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 3623 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 3624 | prev->state = TASK_RUNNING; |
16882c1e | 3625 | else |
2e1cb74a | 3626 | deactivate_task(rq, prev, 1); |
dd41f596 | 3627 | switch_count = &prev->nvcsw; |
1da177e4 LT |
3628 | } |
3629 | ||
3f029d3c | 3630 | pre_schedule(rq, prev); |
f65eda4f | 3631 | |
dd41f596 | 3632 | if (unlikely(!rq->nr_running)) |
1da177e4 | 3633 | idle_balance(cpu, rq); |
1da177e4 | 3634 | |
df1c99d4 | 3635 | put_prev_task(rq, prev); |
b67802ea | 3636 | next = pick_next_task(rq); |
1da177e4 | 3637 | |
1da177e4 | 3638 | if (likely(prev != next)) { |
673a90a1 | 3639 | sched_info_switch(prev, next); |
49f47433 | 3640 | perf_event_task_sched_out(prev, next); |
673a90a1 | 3641 | |
1da177e4 LT |
3642 | rq->nr_switches++; |
3643 | rq->curr = next; | |
3644 | ++*switch_count; | |
3645 | ||
dd41f596 | 3646 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
3647 | /* |
3648 | * the context switch might have flipped the stack from under | |
3649 | * us, hence refresh the local variables. | |
3650 | */ | |
3651 | cpu = smp_processor_id(); | |
3652 | rq = cpu_rq(cpu); | |
1da177e4 | 3653 | } else |
05fa785c | 3654 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 3655 | |
3f029d3c | 3656 | post_schedule(rq); |
1da177e4 | 3657 | |
6d558c3a YZ |
3658 | if (unlikely(reacquire_kernel_lock(current) < 0)) { |
3659 | prev = rq->curr; | |
3660 | switch_count = &prev->nivcsw; | |
1da177e4 | 3661 | goto need_resched_nonpreemptible; |
6d558c3a | 3662 | } |
8f4d37ec | 3663 | |
1da177e4 | 3664 | preempt_enable_no_resched(); |
ff743345 | 3665 | if (need_resched()) |
1da177e4 LT |
3666 | goto need_resched; |
3667 | } | |
1da177e4 LT |
3668 | EXPORT_SYMBOL(schedule); |
3669 | ||
c08f7829 | 3670 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d PZ |
3671 | /* |
3672 | * Look out! "owner" is an entirely speculative pointer | |
3673 | * access and not reliable. | |
3674 | */ | |
3675 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
3676 | { | |
3677 | unsigned int cpu; | |
3678 | struct rq *rq; | |
3679 | ||
3680 | if (!sched_feat(OWNER_SPIN)) | |
3681 | return 0; | |
3682 | ||
3683 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3684 | /* | |
3685 | * Need to access the cpu field knowing that | |
3686 | * DEBUG_PAGEALLOC could have unmapped it if | |
3687 | * the mutex owner just released it and exited. | |
3688 | */ | |
3689 | if (probe_kernel_address(&owner->cpu, cpu)) | |
3690 | goto out; | |
3691 | #else | |
3692 | cpu = owner->cpu; | |
3693 | #endif | |
3694 | ||
3695 | /* | |
3696 | * Even if the access succeeded (likely case), | |
3697 | * the cpu field may no longer be valid. | |
3698 | */ | |
3699 | if (cpu >= nr_cpumask_bits) | |
3700 | goto out; | |
3701 | ||
3702 | /* | |
3703 | * We need to validate that we can do a | |
3704 | * get_cpu() and that we have the percpu area. | |
3705 | */ | |
3706 | if (!cpu_online(cpu)) | |
3707 | goto out; | |
3708 | ||
3709 | rq = cpu_rq(cpu); | |
3710 | ||
3711 | for (;;) { | |
3712 | /* | |
3713 | * Owner changed, break to re-assess state. | |
3714 | */ | |
3715 | if (lock->owner != owner) | |
3716 | break; | |
3717 | ||
3718 | /* | |
3719 | * Is that owner really running on that cpu? | |
3720 | */ | |
3721 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
3722 | return 0; | |
3723 | ||
3724 | cpu_relax(); | |
3725 | } | |
3726 | out: | |
3727 | return 1; | |
3728 | } | |
3729 | #endif | |
3730 | ||
1da177e4 LT |
3731 | #ifdef CONFIG_PREEMPT |
3732 | /* | |
2ed6e34f | 3733 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 3734 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
3735 | * occur there and call schedule directly. |
3736 | */ | |
3737 | asmlinkage void __sched preempt_schedule(void) | |
3738 | { | |
3739 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3740 | |
1da177e4 LT |
3741 | /* |
3742 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 3743 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 3744 | */ |
beed33a8 | 3745 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
3746 | return; |
3747 | ||
3a5c359a AK |
3748 | do { |
3749 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 3750 | schedule(); |
3a5c359a | 3751 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3752 | |
3a5c359a AK |
3753 | /* |
3754 | * Check again in case we missed a preemption opportunity | |
3755 | * between schedule and now. | |
3756 | */ | |
3757 | barrier(); | |
5ed0cec0 | 3758 | } while (need_resched()); |
1da177e4 | 3759 | } |
1da177e4 LT |
3760 | EXPORT_SYMBOL(preempt_schedule); |
3761 | ||
3762 | /* | |
2ed6e34f | 3763 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
3764 | * off of irq context. |
3765 | * Note, that this is called and return with irqs disabled. This will | |
3766 | * protect us against recursive calling from irq. | |
3767 | */ | |
3768 | asmlinkage void __sched preempt_schedule_irq(void) | |
3769 | { | |
3770 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3771 | |
2ed6e34f | 3772 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
3773 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
3774 | ||
3a5c359a AK |
3775 | do { |
3776 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
3777 | local_irq_enable(); |
3778 | schedule(); | |
3779 | local_irq_disable(); | |
3a5c359a | 3780 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3781 | |
3a5c359a AK |
3782 | /* |
3783 | * Check again in case we missed a preemption opportunity | |
3784 | * between schedule and now. | |
3785 | */ | |
3786 | barrier(); | |
5ed0cec0 | 3787 | } while (need_resched()); |
1da177e4 LT |
3788 | } |
3789 | ||
3790 | #endif /* CONFIG_PREEMPT */ | |
3791 | ||
63859d4f | 3792 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3793 | void *key) |
1da177e4 | 3794 | { |
63859d4f | 3795 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3796 | } |
1da177e4 LT |
3797 | EXPORT_SYMBOL(default_wake_function); |
3798 | ||
3799 | /* | |
41a2d6cf IM |
3800 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
3801 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
3802 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
3803 | * | |
3804 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 3805 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
3806 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
3807 | */ | |
78ddb08f | 3808 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 3809 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 3810 | { |
2e45874c | 3811 | wait_queue_t *curr, *next; |
1da177e4 | 3812 | |
2e45874c | 3813 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
3814 | unsigned flags = curr->flags; |
3815 | ||
63859d4f | 3816 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 3817 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
3818 | break; |
3819 | } | |
3820 | } | |
3821 | ||
3822 | /** | |
3823 | * __wake_up - wake up threads blocked on a waitqueue. | |
3824 | * @q: the waitqueue | |
3825 | * @mode: which threads | |
3826 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 3827 | * @key: is directly passed to the wakeup function |
50fa610a DH |
3828 | * |
3829 | * It may be assumed that this function implies a write memory barrier before | |
3830 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3831 | */ |
7ad5b3a5 | 3832 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 3833 | int nr_exclusive, void *key) |
1da177e4 LT |
3834 | { |
3835 | unsigned long flags; | |
3836 | ||
3837 | spin_lock_irqsave(&q->lock, flags); | |
3838 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
3839 | spin_unlock_irqrestore(&q->lock, flags); | |
3840 | } | |
1da177e4 LT |
3841 | EXPORT_SYMBOL(__wake_up); |
3842 | ||
3843 | /* | |
3844 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
3845 | */ | |
7ad5b3a5 | 3846 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
3847 | { |
3848 | __wake_up_common(q, mode, 1, 0, NULL); | |
3849 | } | |
3850 | ||
4ede816a DL |
3851 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
3852 | { | |
3853 | __wake_up_common(q, mode, 1, 0, key); | |
3854 | } | |
3855 | ||
1da177e4 | 3856 | /** |
4ede816a | 3857 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
3858 | * @q: the waitqueue |
3859 | * @mode: which threads | |
3860 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 3861 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
3862 | * |
3863 | * The sync wakeup differs that the waker knows that it will schedule | |
3864 | * away soon, so while the target thread will be woken up, it will not | |
3865 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
3866 | * with each other. This can prevent needless bouncing between CPUs. | |
3867 | * | |
3868 | * On UP it can prevent extra preemption. | |
50fa610a DH |
3869 | * |
3870 | * It may be assumed that this function implies a write memory barrier before | |
3871 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3872 | */ |
4ede816a DL |
3873 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
3874 | int nr_exclusive, void *key) | |
1da177e4 LT |
3875 | { |
3876 | unsigned long flags; | |
7d478721 | 3877 | int wake_flags = WF_SYNC; |
1da177e4 LT |
3878 | |
3879 | if (unlikely(!q)) | |
3880 | return; | |
3881 | ||
3882 | if (unlikely(!nr_exclusive)) | |
7d478721 | 3883 | wake_flags = 0; |
1da177e4 LT |
3884 | |
3885 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 3886 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
3887 | spin_unlock_irqrestore(&q->lock, flags); |
3888 | } | |
4ede816a DL |
3889 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
3890 | ||
3891 | /* | |
3892 | * __wake_up_sync - see __wake_up_sync_key() | |
3893 | */ | |
3894 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
3895 | { | |
3896 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
3897 | } | |
1da177e4 LT |
3898 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
3899 | ||
65eb3dc6 KD |
3900 | /** |
3901 | * complete: - signals a single thread waiting on this completion | |
3902 | * @x: holds the state of this particular completion | |
3903 | * | |
3904 | * This will wake up a single thread waiting on this completion. Threads will be | |
3905 | * awakened in the same order in which they were queued. | |
3906 | * | |
3907 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
3908 | * |
3909 | * It may be assumed that this function implies a write memory barrier before | |
3910 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3911 | */ |
b15136e9 | 3912 | void complete(struct completion *x) |
1da177e4 LT |
3913 | { |
3914 | unsigned long flags; | |
3915 | ||
3916 | spin_lock_irqsave(&x->wait.lock, flags); | |
3917 | x->done++; | |
d9514f6c | 3918 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
3919 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3920 | } | |
3921 | EXPORT_SYMBOL(complete); | |
3922 | ||
65eb3dc6 KD |
3923 | /** |
3924 | * complete_all: - signals all threads waiting on this completion | |
3925 | * @x: holds the state of this particular completion | |
3926 | * | |
3927 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
3928 | * |
3929 | * It may be assumed that this function implies a write memory barrier before | |
3930 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3931 | */ |
b15136e9 | 3932 | void complete_all(struct completion *x) |
1da177e4 LT |
3933 | { |
3934 | unsigned long flags; | |
3935 | ||
3936 | spin_lock_irqsave(&x->wait.lock, flags); | |
3937 | x->done += UINT_MAX/2; | |
d9514f6c | 3938 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
3939 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3940 | } | |
3941 | EXPORT_SYMBOL(complete_all); | |
3942 | ||
8cbbe86d AK |
3943 | static inline long __sched |
3944 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3945 | { |
1da177e4 LT |
3946 | if (!x->done) { |
3947 | DECLARE_WAITQUEUE(wait, current); | |
3948 | ||
3949 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
3950 | __add_wait_queue_tail(&x->wait, &wait); | |
3951 | do { | |
94d3d824 | 3952 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
3953 | timeout = -ERESTARTSYS; |
3954 | break; | |
8cbbe86d AK |
3955 | } |
3956 | __set_current_state(state); | |
1da177e4 LT |
3957 | spin_unlock_irq(&x->wait.lock); |
3958 | timeout = schedule_timeout(timeout); | |
3959 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 3960 | } while (!x->done && timeout); |
1da177e4 | 3961 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
3962 | if (!x->done) |
3963 | return timeout; | |
1da177e4 LT |
3964 | } |
3965 | x->done--; | |
ea71a546 | 3966 | return timeout ?: 1; |
1da177e4 | 3967 | } |
1da177e4 | 3968 | |
8cbbe86d AK |
3969 | static long __sched |
3970 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3971 | { |
1da177e4 LT |
3972 | might_sleep(); |
3973 | ||
3974 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 3975 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 3976 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
3977 | return timeout; |
3978 | } | |
1da177e4 | 3979 | |
65eb3dc6 KD |
3980 | /** |
3981 | * wait_for_completion: - waits for completion of a task | |
3982 | * @x: holds the state of this particular completion | |
3983 | * | |
3984 | * This waits to be signaled for completion of a specific task. It is NOT | |
3985 | * interruptible and there is no timeout. | |
3986 | * | |
3987 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
3988 | * and interrupt capability. Also see complete(). | |
3989 | */ | |
b15136e9 | 3990 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
3991 | { |
3992 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 3993 | } |
8cbbe86d | 3994 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 3995 | |
65eb3dc6 KD |
3996 | /** |
3997 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
3998 | * @x: holds the state of this particular completion | |
3999 | * @timeout: timeout value in jiffies | |
4000 | * | |
4001 | * This waits for either a completion of a specific task to be signaled or for a | |
4002 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4003 | * interruptible. | |
4004 | */ | |
b15136e9 | 4005 | unsigned long __sched |
8cbbe86d | 4006 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4007 | { |
8cbbe86d | 4008 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4009 | } |
8cbbe86d | 4010 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4011 | |
65eb3dc6 KD |
4012 | /** |
4013 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4014 | * @x: holds the state of this particular completion | |
4015 | * | |
4016 | * This waits for completion of a specific task to be signaled. It is | |
4017 | * interruptible. | |
4018 | */ | |
8cbbe86d | 4019 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4020 | { |
51e97990 AK |
4021 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4022 | if (t == -ERESTARTSYS) | |
4023 | return t; | |
4024 | return 0; | |
0fec171c | 4025 | } |
8cbbe86d | 4026 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4027 | |
65eb3dc6 KD |
4028 | /** |
4029 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4030 | * @x: holds the state of this particular completion | |
4031 | * @timeout: timeout value in jiffies | |
4032 | * | |
4033 | * This waits for either a completion of a specific task to be signaled or for a | |
4034 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4035 | */ | |
b15136e9 | 4036 | unsigned long __sched |
8cbbe86d AK |
4037 | wait_for_completion_interruptible_timeout(struct completion *x, |
4038 | unsigned long timeout) | |
0fec171c | 4039 | { |
8cbbe86d | 4040 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4041 | } |
8cbbe86d | 4042 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4043 | |
65eb3dc6 KD |
4044 | /** |
4045 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4046 | * @x: holds the state of this particular completion | |
4047 | * | |
4048 | * This waits to be signaled for completion of a specific task. It can be | |
4049 | * interrupted by a kill signal. | |
4050 | */ | |
009e577e MW |
4051 | int __sched wait_for_completion_killable(struct completion *x) |
4052 | { | |
4053 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4054 | if (t == -ERESTARTSYS) | |
4055 | return t; | |
4056 | return 0; | |
4057 | } | |
4058 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4059 | ||
be4de352 DC |
4060 | /** |
4061 | * try_wait_for_completion - try to decrement a completion without blocking | |
4062 | * @x: completion structure | |
4063 | * | |
4064 | * Returns: 0 if a decrement cannot be done without blocking | |
4065 | * 1 if a decrement succeeded. | |
4066 | * | |
4067 | * If a completion is being used as a counting completion, | |
4068 | * attempt to decrement the counter without blocking. This | |
4069 | * enables us to avoid waiting if the resource the completion | |
4070 | * is protecting is not available. | |
4071 | */ | |
4072 | bool try_wait_for_completion(struct completion *x) | |
4073 | { | |
7539a3b3 | 4074 | unsigned long flags; |
be4de352 DC |
4075 | int ret = 1; |
4076 | ||
7539a3b3 | 4077 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4078 | if (!x->done) |
4079 | ret = 0; | |
4080 | else | |
4081 | x->done--; | |
7539a3b3 | 4082 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4083 | return ret; |
4084 | } | |
4085 | EXPORT_SYMBOL(try_wait_for_completion); | |
4086 | ||
4087 | /** | |
4088 | * completion_done - Test to see if a completion has any waiters | |
4089 | * @x: completion structure | |
4090 | * | |
4091 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4092 | * 1 if there are no waiters. | |
4093 | * | |
4094 | */ | |
4095 | bool completion_done(struct completion *x) | |
4096 | { | |
7539a3b3 | 4097 | unsigned long flags; |
be4de352 DC |
4098 | int ret = 1; |
4099 | ||
7539a3b3 | 4100 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4101 | if (!x->done) |
4102 | ret = 0; | |
7539a3b3 | 4103 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4104 | return ret; |
4105 | } | |
4106 | EXPORT_SYMBOL(completion_done); | |
4107 | ||
8cbbe86d AK |
4108 | static long __sched |
4109 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4110 | { |
0fec171c IM |
4111 | unsigned long flags; |
4112 | wait_queue_t wait; | |
4113 | ||
4114 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4115 | |
8cbbe86d | 4116 | __set_current_state(state); |
1da177e4 | 4117 | |
8cbbe86d AK |
4118 | spin_lock_irqsave(&q->lock, flags); |
4119 | __add_wait_queue(q, &wait); | |
4120 | spin_unlock(&q->lock); | |
4121 | timeout = schedule_timeout(timeout); | |
4122 | spin_lock_irq(&q->lock); | |
4123 | __remove_wait_queue(q, &wait); | |
4124 | spin_unlock_irqrestore(&q->lock, flags); | |
4125 | ||
4126 | return timeout; | |
4127 | } | |
4128 | ||
4129 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4130 | { | |
4131 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4132 | } |
1da177e4 LT |
4133 | EXPORT_SYMBOL(interruptible_sleep_on); |
4134 | ||
0fec171c | 4135 | long __sched |
95cdf3b7 | 4136 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4137 | { |
8cbbe86d | 4138 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4139 | } |
1da177e4 LT |
4140 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4141 | ||
0fec171c | 4142 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4143 | { |
8cbbe86d | 4144 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4145 | } |
1da177e4 LT |
4146 | EXPORT_SYMBOL(sleep_on); |
4147 | ||
0fec171c | 4148 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4149 | { |
8cbbe86d | 4150 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4151 | } |
1da177e4 LT |
4152 | EXPORT_SYMBOL(sleep_on_timeout); |
4153 | ||
b29739f9 IM |
4154 | #ifdef CONFIG_RT_MUTEXES |
4155 | ||
4156 | /* | |
4157 | * rt_mutex_setprio - set the current priority of a task | |
4158 | * @p: task | |
4159 | * @prio: prio value (kernel-internal form) | |
4160 | * | |
4161 | * This function changes the 'effective' priority of a task. It does | |
4162 | * not touch ->normal_prio like __setscheduler(). | |
4163 | * | |
4164 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4165 | */ | |
36c8b586 | 4166 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
4167 | { |
4168 | unsigned long flags; | |
83b699ed | 4169 | int oldprio, on_rq, running; |
70b97a7f | 4170 | struct rq *rq; |
83ab0aa0 | 4171 | const struct sched_class *prev_class; |
b29739f9 IM |
4172 | |
4173 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4174 | ||
4175 | rq = task_rq_lock(p, &flags); | |
4176 | ||
d5f9f942 | 4177 | oldprio = p->prio; |
83ab0aa0 | 4178 | prev_class = p->sched_class; |
dd41f596 | 4179 | on_rq = p->se.on_rq; |
051a1d1a | 4180 | running = task_current(rq, p); |
0e1f3483 | 4181 | if (on_rq) |
69be72c1 | 4182 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
4183 | if (running) |
4184 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
4185 | |
4186 | if (rt_prio(prio)) | |
4187 | p->sched_class = &rt_sched_class; | |
4188 | else | |
4189 | p->sched_class = &fair_sched_class; | |
4190 | ||
b29739f9 IM |
4191 | p->prio = prio; |
4192 | ||
0e1f3483 HS |
4193 | if (running) |
4194 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 4195 | if (on_rq) { |
60db48ca | 4196 | enqueue_task(rq, p, 0, oldprio < prio); |
cb469845 SR |
4197 | |
4198 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
4199 | } |
4200 | task_rq_unlock(rq, &flags); | |
4201 | } | |
4202 | ||
4203 | #endif | |
4204 | ||
36c8b586 | 4205 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 4206 | { |
dd41f596 | 4207 | int old_prio, delta, on_rq; |
1da177e4 | 4208 | unsigned long flags; |
70b97a7f | 4209 | struct rq *rq; |
1da177e4 LT |
4210 | |
4211 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
4212 | return; | |
4213 | /* | |
4214 | * We have to be careful, if called from sys_setpriority(), | |
4215 | * the task might be in the middle of scheduling on another CPU. | |
4216 | */ | |
4217 | rq = task_rq_lock(p, &flags); | |
4218 | /* | |
4219 | * The RT priorities are set via sched_setscheduler(), but we still | |
4220 | * allow the 'normal' nice value to be set - but as expected | |
4221 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 4222 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 4223 | */ |
e05606d3 | 4224 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
4225 | p->static_prio = NICE_TO_PRIO(nice); |
4226 | goto out_unlock; | |
4227 | } | |
dd41f596 | 4228 | on_rq = p->se.on_rq; |
c09595f6 | 4229 | if (on_rq) |
69be72c1 | 4230 | dequeue_task(rq, p, 0); |
1da177e4 | 4231 | |
1da177e4 | 4232 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 4233 | set_load_weight(p); |
b29739f9 IM |
4234 | old_prio = p->prio; |
4235 | p->prio = effective_prio(p); | |
4236 | delta = p->prio - old_prio; | |
1da177e4 | 4237 | |
dd41f596 | 4238 | if (on_rq) { |
ea87bb78 | 4239 | enqueue_task(rq, p, 0, false); |
1da177e4 | 4240 | /* |
d5f9f942 AM |
4241 | * If the task increased its priority or is running and |
4242 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 4243 | */ |
d5f9f942 | 4244 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
4245 | resched_task(rq->curr); |
4246 | } | |
4247 | out_unlock: | |
4248 | task_rq_unlock(rq, &flags); | |
4249 | } | |
1da177e4 LT |
4250 | EXPORT_SYMBOL(set_user_nice); |
4251 | ||
e43379f1 MM |
4252 | /* |
4253 | * can_nice - check if a task can reduce its nice value | |
4254 | * @p: task | |
4255 | * @nice: nice value | |
4256 | */ | |
36c8b586 | 4257 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 4258 | { |
024f4747 MM |
4259 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
4260 | int nice_rlim = 20 - nice; | |
48f24c4d | 4261 | |
78d7d407 | 4262 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
4263 | capable(CAP_SYS_NICE)); |
4264 | } | |
4265 | ||
1da177e4 LT |
4266 | #ifdef __ARCH_WANT_SYS_NICE |
4267 | ||
4268 | /* | |
4269 | * sys_nice - change the priority of the current process. | |
4270 | * @increment: priority increment | |
4271 | * | |
4272 | * sys_setpriority is a more generic, but much slower function that | |
4273 | * does similar things. | |
4274 | */ | |
5add95d4 | 4275 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 4276 | { |
48f24c4d | 4277 | long nice, retval; |
1da177e4 LT |
4278 | |
4279 | /* | |
4280 | * Setpriority might change our priority at the same moment. | |
4281 | * We don't have to worry. Conceptually one call occurs first | |
4282 | * and we have a single winner. | |
4283 | */ | |
e43379f1 MM |
4284 | if (increment < -40) |
4285 | increment = -40; | |
1da177e4 LT |
4286 | if (increment > 40) |
4287 | increment = 40; | |
4288 | ||
2b8f836f | 4289 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
4290 | if (nice < -20) |
4291 | nice = -20; | |
4292 | if (nice > 19) | |
4293 | nice = 19; | |
4294 | ||
e43379f1 MM |
4295 | if (increment < 0 && !can_nice(current, nice)) |
4296 | return -EPERM; | |
4297 | ||
1da177e4 LT |
4298 | retval = security_task_setnice(current, nice); |
4299 | if (retval) | |
4300 | return retval; | |
4301 | ||
4302 | set_user_nice(current, nice); | |
4303 | return 0; | |
4304 | } | |
4305 | ||
4306 | #endif | |
4307 | ||
4308 | /** | |
4309 | * task_prio - return the priority value of a given task. | |
4310 | * @p: the task in question. | |
4311 | * | |
4312 | * This is the priority value as seen by users in /proc. | |
4313 | * RT tasks are offset by -200. Normal tasks are centered | |
4314 | * around 0, value goes from -16 to +15. | |
4315 | */ | |
36c8b586 | 4316 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
4317 | { |
4318 | return p->prio - MAX_RT_PRIO; | |
4319 | } | |
4320 | ||
4321 | /** | |
4322 | * task_nice - return the nice value of a given task. | |
4323 | * @p: the task in question. | |
4324 | */ | |
36c8b586 | 4325 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
4326 | { |
4327 | return TASK_NICE(p); | |
4328 | } | |
150d8bed | 4329 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
4330 | |
4331 | /** | |
4332 | * idle_cpu - is a given cpu idle currently? | |
4333 | * @cpu: the processor in question. | |
4334 | */ | |
4335 | int idle_cpu(int cpu) | |
4336 | { | |
4337 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
4338 | } | |
4339 | ||
1da177e4 LT |
4340 | /** |
4341 | * idle_task - return the idle task for a given cpu. | |
4342 | * @cpu: the processor in question. | |
4343 | */ | |
36c8b586 | 4344 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
4345 | { |
4346 | return cpu_rq(cpu)->idle; | |
4347 | } | |
4348 | ||
4349 | /** | |
4350 | * find_process_by_pid - find a process with a matching PID value. | |
4351 | * @pid: the pid in question. | |
4352 | */ | |
a9957449 | 4353 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 4354 | { |
228ebcbe | 4355 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
4356 | } |
4357 | ||
4358 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
4359 | static void |
4360 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 4361 | { |
dd41f596 | 4362 | BUG_ON(p->se.on_rq); |
48f24c4d | 4363 | |
1da177e4 LT |
4364 | p->policy = policy; |
4365 | p->rt_priority = prio; | |
b29739f9 IM |
4366 | p->normal_prio = normal_prio(p); |
4367 | /* we are holding p->pi_lock already */ | |
4368 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
4369 | if (rt_prio(p->prio)) |
4370 | p->sched_class = &rt_sched_class; | |
4371 | else | |
4372 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 4373 | set_load_weight(p); |
1da177e4 LT |
4374 | } |
4375 | ||
c69e8d9c DH |
4376 | /* |
4377 | * check the target process has a UID that matches the current process's | |
4378 | */ | |
4379 | static bool check_same_owner(struct task_struct *p) | |
4380 | { | |
4381 | const struct cred *cred = current_cred(), *pcred; | |
4382 | bool match; | |
4383 | ||
4384 | rcu_read_lock(); | |
4385 | pcred = __task_cred(p); | |
4386 | match = (cred->euid == pcred->euid || | |
4387 | cred->euid == pcred->uid); | |
4388 | rcu_read_unlock(); | |
4389 | return match; | |
4390 | } | |
4391 | ||
961ccddd RR |
4392 | static int __sched_setscheduler(struct task_struct *p, int policy, |
4393 | struct sched_param *param, bool user) | |
1da177e4 | 4394 | { |
83b699ed | 4395 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 4396 | unsigned long flags; |
83ab0aa0 | 4397 | const struct sched_class *prev_class; |
70b97a7f | 4398 | struct rq *rq; |
ca94c442 | 4399 | int reset_on_fork; |
1da177e4 | 4400 | |
66e5393a SR |
4401 | /* may grab non-irq protected spin_locks */ |
4402 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
4403 | recheck: |
4404 | /* double check policy once rq lock held */ | |
ca94c442 LP |
4405 | if (policy < 0) { |
4406 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 4407 | policy = oldpolicy = p->policy; |
ca94c442 LP |
4408 | } else { |
4409 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
4410 | policy &= ~SCHED_RESET_ON_FORK; | |
4411 | ||
4412 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
4413 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
4414 | policy != SCHED_IDLE) | |
4415 | return -EINVAL; | |
4416 | } | |
4417 | ||
1da177e4 LT |
4418 | /* |
4419 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
4420 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
4421 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
4422 | */ |
4423 | if (param->sched_priority < 0 || | |
95cdf3b7 | 4424 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 4425 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 4426 | return -EINVAL; |
e05606d3 | 4427 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
4428 | return -EINVAL; |
4429 | ||
37e4ab3f OC |
4430 | /* |
4431 | * Allow unprivileged RT tasks to decrease priority: | |
4432 | */ | |
961ccddd | 4433 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 4434 | if (rt_policy(policy)) { |
8dc3e909 | 4435 | unsigned long rlim_rtprio; |
8dc3e909 ON |
4436 | |
4437 | if (!lock_task_sighand(p, &flags)) | |
4438 | return -ESRCH; | |
78d7d407 | 4439 | rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); |
8dc3e909 ON |
4440 | unlock_task_sighand(p, &flags); |
4441 | ||
4442 | /* can't set/change the rt policy */ | |
4443 | if (policy != p->policy && !rlim_rtprio) | |
4444 | return -EPERM; | |
4445 | ||
4446 | /* can't increase priority */ | |
4447 | if (param->sched_priority > p->rt_priority && | |
4448 | param->sched_priority > rlim_rtprio) | |
4449 | return -EPERM; | |
4450 | } | |
dd41f596 IM |
4451 | /* |
4452 | * Like positive nice levels, dont allow tasks to | |
4453 | * move out of SCHED_IDLE either: | |
4454 | */ | |
4455 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
4456 | return -EPERM; | |
5fe1d75f | 4457 | |
37e4ab3f | 4458 | /* can't change other user's priorities */ |
c69e8d9c | 4459 | if (!check_same_owner(p)) |
37e4ab3f | 4460 | return -EPERM; |
ca94c442 LP |
4461 | |
4462 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
4463 | if (p->sched_reset_on_fork && !reset_on_fork) | |
4464 | return -EPERM; | |
37e4ab3f | 4465 | } |
1da177e4 | 4466 | |
725aad24 | 4467 | if (user) { |
b68aa230 | 4468 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
4469 | /* |
4470 | * Do not allow realtime tasks into groups that have no runtime | |
4471 | * assigned. | |
4472 | */ | |
9a7e0b18 PZ |
4473 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
4474 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 4475 | return -EPERM; |
b68aa230 PZ |
4476 | #endif |
4477 | ||
725aad24 JF |
4478 | retval = security_task_setscheduler(p, policy, param); |
4479 | if (retval) | |
4480 | return retval; | |
4481 | } | |
4482 | ||
b29739f9 IM |
4483 | /* |
4484 | * make sure no PI-waiters arrive (or leave) while we are | |
4485 | * changing the priority of the task: | |
4486 | */ | |
1d615482 | 4487 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
1da177e4 LT |
4488 | /* |
4489 | * To be able to change p->policy safely, the apropriate | |
4490 | * runqueue lock must be held. | |
4491 | */ | |
b29739f9 | 4492 | rq = __task_rq_lock(p); |
1da177e4 LT |
4493 | /* recheck policy now with rq lock held */ |
4494 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
4495 | policy = oldpolicy = -1; | |
b29739f9 | 4496 | __task_rq_unlock(rq); |
1d615482 | 4497 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4498 | goto recheck; |
4499 | } | |
dd41f596 | 4500 | on_rq = p->se.on_rq; |
051a1d1a | 4501 | running = task_current(rq, p); |
0e1f3483 | 4502 | if (on_rq) |
2e1cb74a | 4503 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
4504 | if (running) |
4505 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 4506 | |
ca94c442 LP |
4507 | p->sched_reset_on_fork = reset_on_fork; |
4508 | ||
1da177e4 | 4509 | oldprio = p->prio; |
83ab0aa0 | 4510 | prev_class = p->sched_class; |
dd41f596 | 4511 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 4512 | |
0e1f3483 HS |
4513 | if (running) |
4514 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
4515 | if (on_rq) { |
4516 | activate_task(rq, p, 0); | |
cb469845 SR |
4517 | |
4518 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 4519 | } |
b29739f9 | 4520 | __task_rq_unlock(rq); |
1d615482 | 4521 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
b29739f9 | 4522 | |
95e02ca9 TG |
4523 | rt_mutex_adjust_pi(p); |
4524 | ||
1da177e4 LT |
4525 | return 0; |
4526 | } | |
961ccddd RR |
4527 | |
4528 | /** | |
4529 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
4530 | * @p: the task in question. | |
4531 | * @policy: new policy. | |
4532 | * @param: structure containing the new RT priority. | |
4533 | * | |
4534 | * NOTE that the task may be already dead. | |
4535 | */ | |
4536 | int sched_setscheduler(struct task_struct *p, int policy, | |
4537 | struct sched_param *param) | |
4538 | { | |
4539 | return __sched_setscheduler(p, policy, param, true); | |
4540 | } | |
1da177e4 LT |
4541 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
4542 | ||
961ccddd RR |
4543 | /** |
4544 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
4545 | * @p: the task in question. | |
4546 | * @policy: new policy. | |
4547 | * @param: structure containing the new RT priority. | |
4548 | * | |
4549 | * Just like sched_setscheduler, only don't bother checking if the | |
4550 | * current context has permission. For example, this is needed in | |
4551 | * stop_machine(): we create temporary high priority worker threads, | |
4552 | * but our caller might not have that capability. | |
4553 | */ | |
4554 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
4555 | struct sched_param *param) | |
4556 | { | |
4557 | return __sched_setscheduler(p, policy, param, false); | |
4558 | } | |
4559 | ||
95cdf3b7 IM |
4560 | static int |
4561 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 4562 | { |
1da177e4 LT |
4563 | struct sched_param lparam; |
4564 | struct task_struct *p; | |
36c8b586 | 4565 | int retval; |
1da177e4 LT |
4566 | |
4567 | if (!param || pid < 0) | |
4568 | return -EINVAL; | |
4569 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
4570 | return -EFAULT; | |
5fe1d75f ON |
4571 | |
4572 | rcu_read_lock(); | |
4573 | retval = -ESRCH; | |
1da177e4 | 4574 | p = find_process_by_pid(pid); |
5fe1d75f ON |
4575 | if (p != NULL) |
4576 | retval = sched_setscheduler(p, policy, &lparam); | |
4577 | rcu_read_unlock(); | |
36c8b586 | 4578 | |
1da177e4 LT |
4579 | return retval; |
4580 | } | |
4581 | ||
4582 | /** | |
4583 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
4584 | * @pid: the pid in question. | |
4585 | * @policy: new policy. | |
4586 | * @param: structure containing the new RT priority. | |
4587 | */ | |
5add95d4 HC |
4588 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
4589 | struct sched_param __user *, param) | |
1da177e4 | 4590 | { |
c21761f1 JB |
4591 | /* negative values for policy are not valid */ |
4592 | if (policy < 0) | |
4593 | return -EINVAL; | |
4594 | ||
1da177e4 LT |
4595 | return do_sched_setscheduler(pid, policy, param); |
4596 | } | |
4597 | ||
4598 | /** | |
4599 | * sys_sched_setparam - set/change the RT priority of a thread | |
4600 | * @pid: the pid in question. | |
4601 | * @param: structure containing the new RT priority. | |
4602 | */ | |
5add95d4 | 4603 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4604 | { |
4605 | return do_sched_setscheduler(pid, -1, param); | |
4606 | } | |
4607 | ||
4608 | /** | |
4609 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
4610 | * @pid: the pid in question. | |
4611 | */ | |
5add95d4 | 4612 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 4613 | { |
36c8b586 | 4614 | struct task_struct *p; |
3a5c359a | 4615 | int retval; |
1da177e4 LT |
4616 | |
4617 | if (pid < 0) | |
3a5c359a | 4618 | return -EINVAL; |
1da177e4 LT |
4619 | |
4620 | retval = -ESRCH; | |
5fe85be0 | 4621 | rcu_read_lock(); |
1da177e4 LT |
4622 | p = find_process_by_pid(pid); |
4623 | if (p) { | |
4624 | retval = security_task_getscheduler(p); | |
4625 | if (!retval) | |
ca94c442 LP |
4626 | retval = p->policy |
4627 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 4628 | } |
5fe85be0 | 4629 | rcu_read_unlock(); |
1da177e4 LT |
4630 | return retval; |
4631 | } | |
4632 | ||
4633 | /** | |
ca94c442 | 4634 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
4635 | * @pid: the pid in question. |
4636 | * @param: structure containing the RT priority. | |
4637 | */ | |
5add95d4 | 4638 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4639 | { |
4640 | struct sched_param lp; | |
36c8b586 | 4641 | struct task_struct *p; |
3a5c359a | 4642 | int retval; |
1da177e4 LT |
4643 | |
4644 | if (!param || pid < 0) | |
3a5c359a | 4645 | return -EINVAL; |
1da177e4 | 4646 | |
5fe85be0 | 4647 | rcu_read_lock(); |
1da177e4 LT |
4648 | p = find_process_by_pid(pid); |
4649 | retval = -ESRCH; | |
4650 | if (!p) | |
4651 | goto out_unlock; | |
4652 | ||
4653 | retval = security_task_getscheduler(p); | |
4654 | if (retval) | |
4655 | goto out_unlock; | |
4656 | ||
4657 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 4658 | rcu_read_unlock(); |
1da177e4 LT |
4659 | |
4660 | /* | |
4661 | * This one might sleep, we cannot do it with a spinlock held ... | |
4662 | */ | |
4663 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
4664 | ||
1da177e4 LT |
4665 | return retval; |
4666 | ||
4667 | out_unlock: | |
5fe85be0 | 4668 | rcu_read_unlock(); |
1da177e4 LT |
4669 | return retval; |
4670 | } | |
4671 | ||
96f874e2 | 4672 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4673 | { |
5a16f3d3 | 4674 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4675 | struct task_struct *p; |
4676 | int retval; | |
1da177e4 | 4677 | |
95402b38 | 4678 | get_online_cpus(); |
23f5d142 | 4679 | rcu_read_lock(); |
1da177e4 LT |
4680 | |
4681 | p = find_process_by_pid(pid); | |
4682 | if (!p) { | |
23f5d142 | 4683 | rcu_read_unlock(); |
95402b38 | 4684 | put_online_cpus(); |
1da177e4 LT |
4685 | return -ESRCH; |
4686 | } | |
4687 | ||
23f5d142 | 4688 | /* Prevent p going away */ |
1da177e4 | 4689 | get_task_struct(p); |
23f5d142 | 4690 | rcu_read_unlock(); |
1da177e4 | 4691 | |
5a16f3d3 RR |
4692 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4693 | retval = -ENOMEM; | |
4694 | goto out_put_task; | |
4695 | } | |
4696 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4697 | retval = -ENOMEM; | |
4698 | goto out_free_cpus_allowed; | |
4699 | } | |
1da177e4 | 4700 | retval = -EPERM; |
c69e8d9c | 4701 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
4702 | goto out_unlock; |
4703 | ||
e7834f8f DQ |
4704 | retval = security_task_setscheduler(p, 0, NULL); |
4705 | if (retval) | |
4706 | goto out_unlock; | |
4707 | ||
5a16f3d3 RR |
4708 | cpuset_cpus_allowed(p, cpus_allowed); |
4709 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 4710 | again: |
5a16f3d3 | 4711 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4712 | |
8707d8b8 | 4713 | if (!retval) { |
5a16f3d3 RR |
4714 | cpuset_cpus_allowed(p, cpus_allowed); |
4715 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4716 | /* |
4717 | * We must have raced with a concurrent cpuset | |
4718 | * update. Just reset the cpus_allowed to the | |
4719 | * cpuset's cpus_allowed | |
4720 | */ | |
5a16f3d3 | 4721 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4722 | goto again; |
4723 | } | |
4724 | } | |
1da177e4 | 4725 | out_unlock: |
5a16f3d3 RR |
4726 | free_cpumask_var(new_mask); |
4727 | out_free_cpus_allowed: | |
4728 | free_cpumask_var(cpus_allowed); | |
4729 | out_put_task: | |
1da177e4 | 4730 | put_task_struct(p); |
95402b38 | 4731 | put_online_cpus(); |
1da177e4 LT |
4732 | return retval; |
4733 | } | |
4734 | ||
4735 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4736 | struct cpumask *new_mask) |
1da177e4 | 4737 | { |
96f874e2 RR |
4738 | if (len < cpumask_size()) |
4739 | cpumask_clear(new_mask); | |
4740 | else if (len > cpumask_size()) | |
4741 | len = cpumask_size(); | |
4742 | ||
1da177e4 LT |
4743 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4744 | } | |
4745 | ||
4746 | /** | |
4747 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4748 | * @pid: pid of the process | |
4749 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4750 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
4751 | */ | |
5add95d4 HC |
4752 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4753 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4754 | { |
5a16f3d3 | 4755 | cpumask_var_t new_mask; |
1da177e4 LT |
4756 | int retval; |
4757 | ||
5a16f3d3 RR |
4758 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4759 | return -ENOMEM; | |
1da177e4 | 4760 | |
5a16f3d3 RR |
4761 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4762 | if (retval == 0) | |
4763 | retval = sched_setaffinity(pid, new_mask); | |
4764 | free_cpumask_var(new_mask); | |
4765 | return retval; | |
1da177e4 LT |
4766 | } |
4767 | ||
96f874e2 | 4768 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4769 | { |
36c8b586 | 4770 | struct task_struct *p; |
31605683 TG |
4771 | unsigned long flags; |
4772 | struct rq *rq; | |
1da177e4 | 4773 | int retval; |
1da177e4 | 4774 | |
95402b38 | 4775 | get_online_cpus(); |
23f5d142 | 4776 | rcu_read_lock(); |
1da177e4 LT |
4777 | |
4778 | retval = -ESRCH; | |
4779 | p = find_process_by_pid(pid); | |
4780 | if (!p) | |
4781 | goto out_unlock; | |
4782 | ||
e7834f8f DQ |
4783 | retval = security_task_getscheduler(p); |
4784 | if (retval) | |
4785 | goto out_unlock; | |
4786 | ||
31605683 | 4787 | rq = task_rq_lock(p, &flags); |
96f874e2 | 4788 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
31605683 | 4789 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
4790 | |
4791 | out_unlock: | |
23f5d142 | 4792 | rcu_read_unlock(); |
95402b38 | 4793 | put_online_cpus(); |
1da177e4 | 4794 | |
9531b62f | 4795 | return retval; |
1da177e4 LT |
4796 | } |
4797 | ||
4798 | /** | |
4799 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4800 | * @pid: pid of the process | |
4801 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4802 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
4803 | */ | |
5add95d4 HC |
4804 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4805 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4806 | { |
4807 | int ret; | |
f17c8607 | 4808 | cpumask_var_t mask; |
1da177e4 | 4809 | |
cd3d8031 KM |
4810 | if (len < nr_cpu_ids) |
4811 | return -EINVAL; | |
4812 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4813 | return -EINVAL; |
4814 | ||
f17c8607 RR |
4815 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4816 | return -ENOMEM; | |
1da177e4 | 4817 | |
f17c8607 RR |
4818 | ret = sched_getaffinity(pid, mask); |
4819 | if (ret == 0) { | |
8bc037fb | 4820 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4821 | |
4822 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4823 | ret = -EFAULT; |
4824 | else | |
cd3d8031 | 4825 | ret = retlen; |
f17c8607 RR |
4826 | } |
4827 | free_cpumask_var(mask); | |
1da177e4 | 4828 | |
f17c8607 | 4829 | return ret; |
1da177e4 LT |
4830 | } |
4831 | ||
4832 | /** | |
4833 | * sys_sched_yield - yield the current processor to other threads. | |
4834 | * | |
dd41f596 IM |
4835 | * This function yields the current CPU to other tasks. If there are no |
4836 | * other threads running on this CPU then this function will return. | |
1da177e4 | 4837 | */ |
5add95d4 | 4838 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4839 | { |
70b97a7f | 4840 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4841 | |
2d72376b | 4842 | schedstat_inc(rq, yld_count); |
4530d7ab | 4843 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4844 | |
4845 | /* | |
4846 | * Since we are going to call schedule() anyway, there's | |
4847 | * no need to preempt or enable interrupts: | |
4848 | */ | |
4849 | __release(rq->lock); | |
8a25d5de | 4850 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4851 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
4852 | preempt_enable_no_resched(); |
4853 | ||
4854 | schedule(); | |
4855 | ||
4856 | return 0; | |
4857 | } | |
4858 | ||
d86ee480 PZ |
4859 | static inline int should_resched(void) |
4860 | { | |
4861 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
4862 | } | |
4863 | ||
e7b38404 | 4864 | static void __cond_resched(void) |
1da177e4 | 4865 | { |
e7aaaa69 FW |
4866 | add_preempt_count(PREEMPT_ACTIVE); |
4867 | schedule(); | |
4868 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
4869 | } |
4870 | ||
02b67cc3 | 4871 | int __sched _cond_resched(void) |
1da177e4 | 4872 | { |
d86ee480 | 4873 | if (should_resched()) { |
1da177e4 LT |
4874 | __cond_resched(); |
4875 | return 1; | |
4876 | } | |
4877 | return 0; | |
4878 | } | |
02b67cc3 | 4879 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4880 | |
4881 | /* | |
613afbf8 | 4882 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4883 | * call schedule, and on return reacquire the lock. |
4884 | * | |
41a2d6cf | 4885 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4886 | * operations here to prevent schedule() from being called twice (once via |
4887 | * spin_unlock(), once by hand). | |
4888 | */ | |
613afbf8 | 4889 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4890 | { |
d86ee480 | 4891 | int resched = should_resched(); |
6df3cecb JK |
4892 | int ret = 0; |
4893 | ||
f607c668 PZ |
4894 | lockdep_assert_held(lock); |
4895 | ||
95c354fe | 4896 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 4897 | spin_unlock(lock); |
d86ee480 | 4898 | if (resched) |
95c354fe NP |
4899 | __cond_resched(); |
4900 | else | |
4901 | cpu_relax(); | |
6df3cecb | 4902 | ret = 1; |
1da177e4 | 4903 | spin_lock(lock); |
1da177e4 | 4904 | } |
6df3cecb | 4905 | return ret; |
1da177e4 | 4906 | } |
613afbf8 | 4907 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4908 | |
613afbf8 | 4909 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4910 | { |
4911 | BUG_ON(!in_softirq()); | |
4912 | ||
d86ee480 | 4913 | if (should_resched()) { |
98d82567 | 4914 | local_bh_enable(); |
1da177e4 LT |
4915 | __cond_resched(); |
4916 | local_bh_disable(); | |
4917 | return 1; | |
4918 | } | |
4919 | return 0; | |
4920 | } | |
613afbf8 | 4921 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4922 | |
1da177e4 LT |
4923 | /** |
4924 | * yield - yield the current processor to other threads. | |
4925 | * | |
72fd4a35 | 4926 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
4927 | * thread runnable and calls sys_sched_yield(). |
4928 | */ | |
4929 | void __sched yield(void) | |
4930 | { | |
4931 | set_current_state(TASK_RUNNING); | |
4932 | sys_sched_yield(); | |
4933 | } | |
1da177e4 LT |
4934 | EXPORT_SYMBOL(yield); |
4935 | ||
4936 | /* | |
41a2d6cf | 4937 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4938 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4939 | */ |
4940 | void __sched io_schedule(void) | |
4941 | { | |
54d35f29 | 4942 | struct rq *rq = raw_rq(); |
1da177e4 | 4943 | |
0ff92245 | 4944 | delayacct_blkio_start(); |
1da177e4 | 4945 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 4946 | current->in_iowait = 1; |
1da177e4 | 4947 | schedule(); |
8f0dfc34 | 4948 | current->in_iowait = 0; |
1da177e4 | 4949 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4950 | delayacct_blkio_end(); |
1da177e4 | 4951 | } |
1da177e4 LT |
4952 | EXPORT_SYMBOL(io_schedule); |
4953 | ||
4954 | long __sched io_schedule_timeout(long timeout) | |
4955 | { | |
54d35f29 | 4956 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4957 | long ret; |
4958 | ||
0ff92245 | 4959 | delayacct_blkio_start(); |
1da177e4 | 4960 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 4961 | current->in_iowait = 1; |
1da177e4 | 4962 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4963 | current->in_iowait = 0; |
1da177e4 | 4964 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4965 | delayacct_blkio_end(); |
1da177e4 LT |
4966 | return ret; |
4967 | } | |
4968 | ||
4969 | /** | |
4970 | * sys_sched_get_priority_max - return maximum RT priority. | |
4971 | * @policy: scheduling class. | |
4972 | * | |
4973 | * this syscall returns the maximum rt_priority that can be used | |
4974 | * by a given scheduling class. | |
4975 | */ | |
5add95d4 | 4976 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4977 | { |
4978 | int ret = -EINVAL; | |
4979 | ||
4980 | switch (policy) { | |
4981 | case SCHED_FIFO: | |
4982 | case SCHED_RR: | |
4983 | ret = MAX_USER_RT_PRIO-1; | |
4984 | break; | |
4985 | case SCHED_NORMAL: | |
b0a9499c | 4986 | case SCHED_BATCH: |
dd41f596 | 4987 | case SCHED_IDLE: |
1da177e4 LT |
4988 | ret = 0; |
4989 | break; | |
4990 | } | |
4991 | return ret; | |
4992 | } | |
4993 | ||
4994 | /** | |
4995 | * sys_sched_get_priority_min - return minimum RT priority. | |
4996 | * @policy: scheduling class. | |
4997 | * | |
4998 | * this syscall returns the minimum rt_priority that can be used | |
4999 | * by a given scheduling class. | |
5000 | */ | |
5add95d4 | 5001 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5002 | { |
5003 | int ret = -EINVAL; | |
5004 | ||
5005 | switch (policy) { | |
5006 | case SCHED_FIFO: | |
5007 | case SCHED_RR: | |
5008 | ret = 1; | |
5009 | break; | |
5010 | case SCHED_NORMAL: | |
b0a9499c | 5011 | case SCHED_BATCH: |
dd41f596 | 5012 | case SCHED_IDLE: |
1da177e4 LT |
5013 | ret = 0; |
5014 | } | |
5015 | return ret; | |
5016 | } | |
5017 | ||
5018 | /** | |
5019 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5020 | * @pid: pid of the process. | |
5021 | * @interval: userspace pointer to the timeslice value. | |
5022 | * | |
5023 | * this syscall writes the default timeslice value of a given process | |
5024 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5025 | */ | |
17da2bd9 | 5026 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5027 | struct timespec __user *, interval) |
1da177e4 | 5028 | { |
36c8b586 | 5029 | struct task_struct *p; |
a4ec24b4 | 5030 | unsigned int time_slice; |
dba091b9 TG |
5031 | unsigned long flags; |
5032 | struct rq *rq; | |
3a5c359a | 5033 | int retval; |
1da177e4 | 5034 | struct timespec t; |
1da177e4 LT |
5035 | |
5036 | if (pid < 0) | |
3a5c359a | 5037 | return -EINVAL; |
1da177e4 LT |
5038 | |
5039 | retval = -ESRCH; | |
1a551ae7 | 5040 | rcu_read_lock(); |
1da177e4 LT |
5041 | p = find_process_by_pid(pid); |
5042 | if (!p) | |
5043 | goto out_unlock; | |
5044 | ||
5045 | retval = security_task_getscheduler(p); | |
5046 | if (retval) | |
5047 | goto out_unlock; | |
5048 | ||
dba091b9 TG |
5049 | rq = task_rq_lock(p, &flags); |
5050 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
5051 | task_rq_unlock(rq, &flags); | |
a4ec24b4 | 5052 | |
1a551ae7 | 5053 | rcu_read_unlock(); |
a4ec24b4 | 5054 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5055 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5056 | return retval; |
3a5c359a | 5057 | |
1da177e4 | 5058 | out_unlock: |
1a551ae7 | 5059 | rcu_read_unlock(); |
1da177e4 LT |
5060 | return retval; |
5061 | } | |
5062 | ||
7c731e0a | 5063 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5064 | |
82a1fcb9 | 5065 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5066 | { |
1da177e4 | 5067 | unsigned long free = 0; |
36c8b586 | 5068 | unsigned state; |
1da177e4 | 5069 | |
1da177e4 | 5070 | state = p->state ? __ffs(p->state) + 1 : 0; |
3df0fc5b | 5071 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 5072 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5073 | #if BITS_PER_LONG == 32 |
1da177e4 | 5074 | if (state == TASK_RUNNING) |
3df0fc5b | 5075 | printk(KERN_CONT " running "); |
1da177e4 | 5076 | else |
3df0fc5b | 5077 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5078 | #else |
5079 | if (state == TASK_RUNNING) | |
3df0fc5b | 5080 | printk(KERN_CONT " running task "); |
1da177e4 | 5081 | else |
3df0fc5b | 5082 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
5083 | #endif |
5084 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 5085 | free = stack_not_used(p); |
1da177e4 | 5086 | #endif |
3df0fc5b | 5087 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
5088 | task_pid_nr(p), task_pid_nr(p->real_parent), |
5089 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 5090 | |
5fb5e6de | 5091 | show_stack(p, NULL); |
1da177e4 LT |
5092 | } |
5093 | ||
e59e2ae2 | 5094 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 5095 | { |
36c8b586 | 5096 | struct task_struct *g, *p; |
1da177e4 | 5097 | |
4bd77321 | 5098 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
5099 | printk(KERN_INFO |
5100 | " task PC stack pid father\n"); | |
1da177e4 | 5101 | #else |
3df0fc5b PZ |
5102 | printk(KERN_INFO |
5103 | " task PC stack pid father\n"); | |
1da177e4 LT |
5104 | #endif |
5105 | read_lock(&tasklist_lock); | |
5106 | do_each_thread(g, p) { | |
5107 | /* | |
5108 | * reset the NMI-timeout, listing all files on a slow | |
5109 | * console might take alot of time: | |
5110 | */ | |
5111 | touch_nmi_watchdog(); | |
39bc89fd | 5112 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 5113 | sched_show_task(p); |
1da177e4 LT |
5114 | } while_each_thread(g, p); |
5115 | ||
04c9167f JF |
5116 | touch_all_softlockup_watchdogs(); |
5117 | ||
dd41f596 IM |
5118 | #ifdef CONFIG_SCHED_DEBUG |
5119 | sysrq_sched_debug_show(); | |
5120 | #endif | |
1da177e4 | 5121 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
5122 | /* |
5123 | * Only show locks if all tasks are dumped: | |
5124 | */ | |
93335a21 | 5125 | if (!state_filter) |
e59e2ae2 | 5126 | debug_show_all_locks(); |
1da177e4 LT |
5127 | } |
5128 | ||
1df21055 IM |
5129 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
5130 | { | |
dd41f596 | 5131 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
5132 | } |
5133 | ||
f340c0d1 IM |
5134 | /** |
5135 | * init_idle - set up an idle thread for a given CPU | |
5136 | * @idle: task in question | |
5137 | * @cpu: cpu the idle task belongs to | |
5138 | * | |
5139 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
5140 | * flag, to make booting more robust. | |
5141 | */ | |
5c1e1767 | 5142 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 5143 | { |
70b97a7f | 5144 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5145 | unsigned long flags; |
5146 | ||
05fa785c | 5147 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 5148 | |
dd41f596 | 5149 | __sched_fork(idle); |
06b83b5f | 5150 | idle->state = TASK_RUNNING; |
dd41f596 IM |
5151 | idle->se.exec_start = sched_clock(); |
5152 | ||
96f874e2 | 5153 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 5154 | __set_task_cpu(idle, cpu); |
1da177e4 | 5155 | |
1da177e4 | 5156 | rq->curr = rq->idle = idle; |
4866cde0 NP |
5157 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
5158 | idle->oncpu = 1; | |
5159 | #endif | |
05fa785c | 5160 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5161 | |
5162 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
5163 | #if defined(CONFIG_PREEMPT) |
5164 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
5165 | #else | |
a1261f54 | 5166 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 5167 | #endif |
dd41f596 IM |
5168 | /* |
5169 | * The idle tasks have their own, simple scheduling class: | |
5170 | */ | |
5171 | idle->sched_class = &idle_sched_class; | |
fb52607a | 5172 | ftrace_graph_init_task(idle); |
1da177e4 LT |
5173 | } |
5174 | ||
5175 | /* | |
5176 | * In a system that switches off the HZ timer nohz_cpu_mask | |
5177 | * indicates which cpus entered this state. This is used | |
5178 | * in the rcu update to wait only for active cpus. For system | |
5179 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 5180 | * always be CPU_BITS_NONE. |
1da177e4 | 5181 | */ |
6a7b3dc3 | 5182 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 5183 | |
19978ca6 IM |
5184 | /* |
5185 | * Increase the granularity value when there are more CPUs, | |
5186 | * because with more CPUs the 'effective latency' as visible | |
5187 | * to users decreases. But the relationship is not linear, | |
5188 | * so pick a second-best guess by going with the log2 of the | |
5189 | * number of CPUs. | |
5190 | * | |
5191 | * This idea comes from the SD scheduler of Con Kolivas: | |
5192 | */ | |
acb4a848 | 5193 | static int get_update_sysctl_factor(void) |
19978ca6 | 5194 | { |
4ca3ef71 | 5195 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
5196 | unsigned int factor; |
5197 | ||
5198 | switch (sysctl_sched_tunable_scaling) { | |
5199 | case SCHED_TUNABLESCALING_NONE: | |
5200 | factor = 1; | |
5201 | break; | |
5202 | case SCHED_TUNABLESCALING_LINEAR: | |
5203 | factor = cpus; | |
5204 | break; | |
5205 | case SCHED_TUNABLESCALING_LOG: | |
5206 | default: | |
5207 | factor = 1 + ilog2(cpus); | |
5208 | break; | |
5209 | } | |
19978ca6 | 5210 | |
acb4a848 CE |
5211 | return factor; |
5212 | } | |
19978ca6 | 5213 | |
acb4a848 CE |
5214 | static void update_sysctl(void) |
5215 | { | |
5216 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 5217 | |
0bcdcf28 CE |
5218 | #define SET_SYSCTL(name) \ |
5219 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
5220 | SET_SYSCTL(sched_min_granularity); | |
5221 | SET_SYSCTL(sched_latency); | |
5222 | SET_SYSCTL(sched_wakeup_granularity); | |
5223 | SET_SYSCTL(sched_shares_ratelimit); | |
5224 | #undef SET_SYSCTL | |
5225 | } | |
55cd5340 | 5226 | |
0bcdcf28 CE |
5227 | static inline void sched_init_granularity(void) |
5228 | { | |
5229 | update_sysctl(); | |
19978ca6 IM |
5230 | } |
5231 | ||
1da177e4 LT |
5232 | #ifdef CONFIG_SMP |
5233 | /* | |
5234 | * This is how migration works: | |
5235 | * | |
70b97a7f | 5236 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
5237 | * runqueue and wake up that CPU's migration thread. |
5238 | * 2) we down() the locked semaphore => thread blocks. | |
5239 | * 3) migration thread wakes up (implicitly it forces the migrated | |
5240 | * thread off the CPU) | |
5241 | * 4) it gets the migration request and checks whether the migrated | |
5242 | * task is still in the wrong runqueue. | |
5243 | * 5) if it's in the wrong runqueue then the migration thread removes | |
5244 | * it and puts it into the right queue. | |
5245 | * 6) migration thread up()s the semaphore. | |
5246 | * 7) we wake up and the migration is done. | |
5247 | */ | |
5248 | ||
5249 | /* | |
5250 | * Change a given task's CPU affinity. Migrate the thread to a | |
5251 | * proper CPU and schedule it away if the CPU it's executing on | |
5252 | * is removed from the allowed bitmask. | |
5253 | * | |
5254 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 5255 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
5256 | * call is not atomic; no spinlocks may be held. |
5257 | */ | |
96f874e2 | 5258 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 5259 | { |
70b97a7f | 5260 | struct migration_req req; |
1da177e4 | 5261 | unsigned long flags; |
70b97a7f | 5262 | struct rq *rq; |
48f24c4d | 5263 | int ret = 0; |
1da177e4 | 5264 | |
65cc8e48 PZ |
5265 | /* |
5266 | * Serialize against TASK_WAKING so that ttwu() and wunt() can | |
5267 | * drop the rq->lock and still rely on ->cpus_allowed. | |
5268 | */ | |
5269 | again: | |
5270 | while (task_is_waking(p)) | |
5271 | cpu_relax(); | |
1da177e4 | 5272 | rq = task_rq_lock(p, &flags); |
65cc8e48 PZ |
5273 | if (task_is_waking(p)) { |
5274 | task_rq_unlock(rq, &flags); | |
5275 | goto again; | |
5276 | } | |
e2912009 | 5277 | |
6ad4c188 | 5278 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
5279 | ret = -EINVAL; |
5280 | goto out; | |
5281 | } | |
5282 | ||
9985b0ba | 5283 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 5284 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
5285 | ret = -EINVAL; |
5286 | goto out; | |
5287 | } | |
5288 | ||
73fe6aae | 5289 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 5290 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 5291 | else { |
96f874e2 RR |
5292 | cpumask_copy(&p->cpus_allowed, new_mask); |
5293 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
5294 | } |
5295 | ||
1da177e4 | 5296 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 5297 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
5298 | goto out; |
5299 | ||
6ad4c188 | 5300 | if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) { |
1da177e4 | 5301 | /* Need help from migration thread: drop lock and wait. */ |
693525e3 PZ |
5302 | struct task_struct *mt = rq->migration_thread; |
5303 | ||
5304 | get_task_struct(mt); | |
1da177e4 LT |
5305 | task_rq_unlock(rq, &flags); |
5306 | wake_up_process(rq->migration_thread); | |
693525e3 | 5307 | put_task_struct(mt); |
1da177e4 LT |
5308 | wait_for_completion(&req.done); |
5309 | tlb_migrate_finish(p->mm); | |
5310 | return 0; | |
5311 | } | |
5312 | out: | |
5313 | task_rq_unlock(rq, &flags); | |
48f24c4d | 5314 | |
1da177e4 LT |
5315 | return ret; |
5316 | } | |
cd8ba7cd | 5317 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
5318 | |
5319 | /* | |
41a2d6cf | 5320 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
5321 | * this because either it can't run here any more (set_cpus_allowed() |
5322 | * away from this CPU, or CPU going down), or because we're | |
5323 | * attempting to rebalance this task on exec (sched_exec). | |
5324 | * | |
5325 | * So we race with normal scheduler movements, but that's OK, as long | |
5326 | * as the task is no longer on this CPU. | |
efc30814 KK |
5327 | * |
5328 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 5329 | */ |
efc30814 | 5330 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 5331 | { |
70b97a7f | 5332 | struct rq *rq_dest, *rq_src; |
e2912009 | 5333 | int ret = 0; |
1da177e4 | 5334 | |
e761b772 | 5335 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 5336 | return ret; |
1da177e4 LT |
5337 | |
5338 | rq_src = cpu_rq(src_cpu); | |
5339 | rq_dest = cpu_rq(dest_cpu); | |
5340 | ||
5341 | double_rq_lock(rq_src, rq_dest); | |
5342 | /* Already moved. */ | |
5343 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 5344 | goto done; |
1da177e4 | 5345 | /* Affinity changed (again). */ |
96f874e2 | 5346 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 5347 | goto fail; |
1da177e4 | 5348 | |
e2912009 PZ |
5349 | /* |
5350 | * If we're not on a rq, the next wake-up will ensure we're | |
5351 | * placed properly. | |
5352 | */ | |
5353 | if (p->se.on_rq) { | |
2e1cb74a | 5354 | deactivate_task(rq_src, p, 0); |
e2912009 | 5355 | set_task_cpu(p, dest_cpu); |
dd41f596 | 5356 | activate_task(rq_dest, p, 0); |
15afe09b | 5357 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 5358 | } |
b1e38734 | 5359 | done: |
efc30814 | 5360 | ret = 1; |
b1e38734 | 5361 | fail: |
1da177e4 | 5362 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 5363 | return ret; |
1da177e4 LT |
5364 | } |
5365 | ||
03b042bf PM |
5366 | #define RCU_MIGRATION_IDLE 0 |
5367 | #define RCU_MIGRATION_NEED_QS 1 | |
5368 | #define RCU_MIGRATION_GOT_QS 2 | |
5369 | #define RCU_MIGRATION_MUST_SYNC 3 | |
5370 | ||
1da177e4 LT |
5371 | /* |
5372 | * migration_thread - this is a highprio system thread that performs | |
5373 | * thread migration by bumping thread off CPU then 'pushing' onto | |
5374 | * another runqueue. | |
5375 | */ | |
95cdf3b7 | 5376 | static int migration_thread(void *data) |
1da177e4 | 5377 | { |
03b042bf | 5378 | int badcpu; |
1da177e4 | 5379 | int cpu = (long)data; |
70b97a7f | 5380 | struct rq *rq; |
1da177e4 LT |
5381 | |
5382 | rq = cpu_rq(cpu); | |
5383 | BUG_ON(rq->migration_thread != current); | |
5384 | ||
5385 | set_current_state(TASK_INTERRUPTIBLE); | |
5386 | while (!kthread_should_stop()) { | |
70b97a7f | 5387 | struct migration_req *req; |
1da177e4 | 5388 | struct list_head *head; |
1da177e4 | 5389 | |
05fa785c | 5390 | raw_spin_lock_irq(&rq->lock); |
1da177e4 LT |
5391 | |
5392 | if (cpu_is_offline(cpu)) { | |
05fa785c | 5393 | raw_spin_unlock_irq(&rq->lock); |
371cbb38 | 5394 | break; |
1da177e4 LT |
5395 | } |
5396 | ||
5397 | if (rq->active_balance) { | |
5398 | active_load_balance(rq, cpu); | |
5399 | rq->active_balance = 0; | |
5400 | } | |
5401 | ||
5402 | head = &rq->migration_queue; | |
5403 | ||
5404 | if (list_empty(head)) { | |
05fa785c | 5405 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
5406 | schedule(); |
5407 | set_current_state(TASK_INTERRUPTIBLE); | |
5408 | continue; | |
5409 | } | |
70b97a7f | 5410 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
5411 | list_del_init(head->next); |
5412 | ||
03b042bf | 5413 | if (req->task != NULL) { |
05fa785c | 5414 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
5415 | __migrate_task(req->task, cpu, req->dest_cpu); |
5416 | } else if (likely(cpu == (badcpu = smp_processor_id()))) { | |
5417 | req->dest_cpu = RCU_MIGRATION_GOT_QS; | |
05fa785c | 5418 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
5419 | } else { |
5420 | req->dest_cpu = RCU_MIGRATION_MUST_SYNC; | |
05fa785c | 5421 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
5422 | WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu); |
5423 | } | |
674311d5 | 5424 | local_irq_enable(); |
1da177e4 LT |
5425 | |
5426 | complete(&req->done); | |
5427 | } | |
5428 | __set_current_state(TASK_RUNNING); | |
1da177e4 | 5429 | |
1da177e4 LT |
5430 | return 0; |
5431 | } | |
5432 | ||
5433 | #ifdef CONFIG_HOTPLUG_CPU | |
054b9108 | 5434 | /* |
3a4fa0a2 | 5435 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 5436 | */ |
6a1bdc1b | 5437 | void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 5438 | { |
1445c08d ON |
5439 | struct rq *rq = cpu_rq(dead_cpu); |
5440 | int needs_cpu, uninitialized_var(dest_cpu); | |
5441 | unsigned long flags; | |
c1804d54 | 5442 | |
1445c08d ON |
5443 | local_irq_save(flags); |
5444 | ||
5445 | raw_spin_lock(&rq->lock); | |
5446 | needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING); | |
5447 | if (needs_cpu) | |
5448 | dest_cpu = select_fallback_rq(dead_cpu, p); | |
5449 | raw_spin_unlock(&rq->lock); | |
c1804d54 ON |
5450 | /* |
5451 | * It can only fail if we race with set_cpus_allowed(), | |
5452 | * in the racer should migrate the task anyway. | |
5453 | */ | |
1445c08d | 5454 | if (needs_cpu) |
c1804d54 | 5455 | __migrate_task(p, dead_cpu, dest_cpu); |
1445c08d | 5456 | local_irq_restore(flags); |
1da177e4 LT |
5457 | } |
5458 | ||
5459 | /* | |
5460 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
5461 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
5462 | * for performance reasons the counter is not stricly tracking tasks to | |
5463 | * their home CPUs. So we just add the counter to another CPU's counter, | |
5464 | * to keep the global sum constant after CPU-down: | |
5465 | */ | |
70b97a7f | 5466 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 5467 | { |
6ad4c188 | 5468 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 LT |
5469 | unsigned long flags; |
5470 | ||
5471 | local_irq_save(flags); | |
5472 | double_rq_lock(rq_src, rq_dest); | |
5473 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
5474 | rq_src->nr_uninterruptible = 0; | |
5475 | double_rq_unlock(rq_src, rq_dest); | |
5476 | local_irq_restore(flags); | |
5477 | } | |
5478 | ||
5479 | /* Run through task list and migrate tasks from the dead cpu. */ | |
5480 | static void migrate_live_tasks(int src_cpu) | |
5481 | { | |
48f24c4d | 5482 | struct task_struct *p, *t; |
1da177e4 | 5483 | |
f7b4cddc | 5484 | read_lock(&tasklist_lock); |
1da177e4 | 5485 | |
48f24c4d IM |
5486 | do_each_thread(t, p) { |
5487 | if (p == current) | |
1da177e4 LT |
5488 | continue; |
5489 | ||
48f24c4d IM |
5490 | if (task_cpu(p) == src_cpu) |
5491 | move_task_off_dead_cpu(src_cpu, p); | |
5492 | } while_each_thread(t, p); | |
1da177e4 | 5493 | |
f7b4cddc | 5494 | read_unlock(&tasklist_lock); |
1da177e4 LT |
5495 | } |
5496 | ||
dd41f596 IM |
5497 | /* |
5498 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
5499 | * It does so by boosting its priority to highest possible. |
5500 | * Used by CPU offline code. | |
1da177e4 LT |
5501 | */ |
5502 | void sched_idle_next(void) | |
5503 | { | |
48f24c4d | 5504 | int this_cpu = smp_processor_id(); |
70b97a7f | 5505 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
5506 | struct task_struct *p = rq->idle; |
5507 | unsigned long flags; | |
5508 | ||
5509 | /* cpu has to be offline */ | |
48f24c4d | 5510 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 5511 | |
48f24c4d IM |
5512 | /* |
5513 | * Strictly not necessary since rest of the CPUs are stopped by now | |
5514 | * and interrupts disabled on the current cpu. | |
1da177e4 | 5515 | */ |
05fa785c | 5516 | raw_spin_lock_irqsave(&rq->lock, flags); |
1da177e4 | 5517 | |
dd41f596 | 5518 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 5519 | |
94bc9a7b | 5520 | activate_task(rq, p, 0); |
1da177e4 | 5521 | |
05fa785c | 5522 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5523 | } |
5524 | ||
48f24c4d IM |
5525 | /* |
5526 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
5527 | * offline. |
5528 | */ | |
5529 | void idle_task_exit(void) | |
5530 | { | |
5531 | struct mm_struct *mm = current->active_mm; | |
5532 | ||
5533 | BUG_ON(cpu_online(smp_processor_id())); | |
5534 | ||
5535 | if (mm != &init_mm) | |
5536 | switch_mm(mm, &init_mm, current); | |
5537 | mmdrop(mm); | |
5538 | } | |
5539 | ||
054b9108 | 5540 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 5541 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 5542 | { |
70b97a7f | 5543 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
5544 | |
5545 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 5546 | BUG_ON(!p->exit_state); |
1da177e4 LT |
5547 | |
5548 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 5549 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 5550 | |
48f24c4d | 5551 | get_task_struct(p); |
1da177e4 LT |
5552 | |
5553 | /* | |
5554 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 5555 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
5556 | * fine. |
5557 | */ | |
05fa785c | 5558 | raw_spin_unlock_irq(&rq->lock); |
48f24c4d | 5559 | move_task_off_dead_cpu(dead_cpu, p); |
05fa785c | 5560 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5561 | |
48f24c4d | 5562 | put_task_struct(p); |
1da177e4 LT |
5563 | } |
5564 | ||
5565 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
5566 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
5567 | { | |
70b97a7f | 5568 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 5569 | struct task_struct *next; |
48f24c4d | 5570 | |
dd41f596 IM |
5571 | for ( ; ; ) { |
5572 | if (!rq->nr_running) | |
5573 | break; | |
b67802ea | 5574 | next = pick_next_task(rq); |
dd41f596 IM |
5575 | if (!next) |
5576 | break; | |
79c53799 | 5577 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 5578 | migrate_dead(dead_cpu, next); |
e692ab53 | 5579 | |
1da177e4 LT |
5580 | } |
5581 | } | |
dce48a84 TG |
5582 | |
5583 | /* | |
5584 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
5585 | */ | |
5586 | static void calc_global_load_remove(struct rq *rq) | |
5587 | { | |
5588 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 5589 | rq->calc_load_active = 0; |
dce48a84 | 5590 | } |
1da177e4 LT |
5591 | #endif /* CONFIG_HOTPLUG_CPU */ |
5592 | ||
e692ab53 NP |
5593 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
5594 | ||
5595 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
5596 | { |
5597 | .procname = "sched_domain", | |
c57baf1e | 5598 | .mode = 0555, |
e0361851 | 5599 | }, |
56992309 | 5600 | {} |
e692ab53 NP |
5601 | }; |
5602 | ||
5603 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
5604 | { |
5605 | .procname = "kernel", | |
c57baf1e | 5606 | .mode = 0555, |
e0361851 AD |
5607 | .child = sd_ctl_dir, |
5608 | }, | |
56992309 | 5609 | {} |
e692ab53 NP |
5610 | }; |
5611 | ||
5612 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
5613 | { | |
5614 | struct ctl_table *entry = | |
5cf9f062 | 5615 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 5616 | |
e692ab53 NP |
5617 | return entry; |
5618 | } | |
5619 | ||
6382bc90 MM |
5620 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
5621 | { | |
cd790076 | 5622 | struct ctl_table *entry; |
6382bc90 | 5623 | |
cd790076 MM |
5624 | /* |
5625 | * In the intermediate directories, both the child directory and | |
5626 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 5627 | * will always be set. In the lowest directory the names are |
cd790076 MM |
5628 | * static strings and all have proc handlers. |
5629 | */ | |
5630 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
5631 | if (entry->child) |
5632 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
5633 | if (entry->proc_handler == NULL) |
5634 | kfree(entry->procname); | |
5635 | } | |
6382bc90 MM |
5636 | |
5637 | kfree(*tablep); | |
5638 | *tablep = NULL; | |
5639 | } | |
5640 | ||
e692ab53 | 5641 | static void |
e0361851 | 5642 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
5643 | const char *procname, void *data, int maxlen, |
5644 | mode_t mode, proc_handler *proc_handler) | |
5645 | { | |
e692ab53 NP |
5646 | entry->procname = procname; |
5647 | entry->data = data; | |
5648 | entry->maxlen = maxlen; | |
5649 | entry->mode = mode; | |
5650 | entry->proc_handler = proc_handler; | |
5651 | } | |
5652 | ||
5653 | static struct ctl_table * | |
5654 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
5655 | { | |
a5d8c348 | 5656 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 5657 | |
ad1cdc1d MM |
5658 | if (table == NULL) |
5659 | return NULL; | |
5660 | ||
e0361851 | 5661 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 5662 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5663 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 5664 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5665 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 5666 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5667 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 5668 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5669 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 5670 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5671 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 5672 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5673 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 5674 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5675 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 5676 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5677 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 5678 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 5679 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
5680 | &sd->cache_nice_tries, |
5681 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 5682 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 5683 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
5684 | set_table_entry(&table[11], "name", sd->name, |
5685 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
5686 | /* &table[12] is terminator */ | |
e692ab53 NP |
5687 | |
5688 | return table; | |
5689 | } | |
5690 | ||
9a4e7159 | 5691 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
5692 | { |
5693 | struct ctl_table *entry, *table; | |
5694 | struct sched_domain *sd; | |
5695 | int domain_num = 0, i; | |
5696 | char buf[32]; | |
5697 | ||
5698 | for_each_domain(cpu, sd) | |
5699 | domain_num++; | |
5700 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5701 | if (table == NULL) |
5702 | return NULL; | |
e692ab53 NP |
5703 | |
5704 | i = 0; | |
5705 | for_each_domain(cpu, sd) { | |
5706 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5707 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5708 | entry->mode = 0555; |
e692ab53 NP |
5709 | entry->child = sd_alloc_ctl_domain_table(sd); |
5710 | entry++; | |
5711 | i++; | |
5712 | } | |
5713 | return table; | |
5714 | } | |
5715 | ||
5716 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5717 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5718 | { |
6ad4c188 | 5719 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5720 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5721 | char buf[32]; | |
5722 | ||
7378547f MM |
5723 | WARN_ON(sd_ctl_dir[0].child); |
5724 | sd_ctl_dir[0].child = entry; | |
5725 | ||
ad1cdc1d MM |
5726 | if (entry == NULL) |
5727 | return; | |
5728 | ||
6ad4c188 | 5729 | for_each_possible_cpu(i) { |
e692ab53 | 5730 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5731 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5732 | entry->mode = 0555; |
e692ab53 | 5733 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5734 | entry++; |
e692ab53 | 5735 | } |
7378547f MM |
5736 | |
5737 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5738 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5739 | } | |
6382bc90 | 5740 | |
7378547f | 5741 | /* may be called multiple times per register */ |
6382bc90 MM |
5742 | static void unregister_sched_domain_sysctl(void) |
5743 | { | |
7378547f MM |
5744 | if (sd_sysctl_header) |
5745 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5746 | sd_sysctl_header = NULL; |
7378547f MM |
5747 | if (sd_ctl_dir[0].child) |
5748 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5749 | } |
e692ab53 | 5750 | #else |
6382bc90 MM |
5751 | static void register_sched_domain_sysctl(void) |
5752 | { | |
5753 | } | |
5754 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5755 | { |
5756 | } | |
5757 | #endif | |
5758 | ||
1f11eb6a GH |
5759 | static void set_rq_online(struct rq *rq) |
5760 | { | |
5761 | if (!rq->online) { | |
5762 | const struct sched_class *class; | |
5763 | ||
c6c4927b | 5764 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5765 | rq->online = 1; |
5766 | ||
5767 | for_each_class(class) { | |
5768 | if (class->rq_online) | |
5769 | class->rq_online(rq); | |
5770 | } | |
5771 | } | |
5772 | } | |
5773 | ||
5774 | static void set_rq_offline(struct rq *rq) | |
5775 | { | |
5776 | if (rq->online) { | |
5777 | const struct sched_class *class; | |
5778 | ||
5779 | for_each_class(class) { | |
5780 | if (class->rq_offline) | |
5781 | class->rq_offline(rq); | |
5782 | } | |
5783 | ||
c6c4927b | 5784 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5785 | rq->online = 0; |
5786 | } | |
5787 | } | |
5788 | ||
1da177e4 LT |
5789 | /* |
5790 | * migration_call - callback that gets triggered when a CPU is added. | |
5791 | * Here we can start up the necessary migration thread for the new CPU. | |
5792 | */ | |
48f24c4d IM |
5793 | static int __cpuinit |
5794 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 5795 | { |
1da177e4 | 5796 | struct task_struct *p; |
48f24c4d | 5797 | int cpu = (long)hcpu; |
1da177e4 | 5798 | unsigned long flags; |
70b97a7f | 5799 | struct rq *rq; |
1da177e4 LT |
5800 | |
5801 | switch (action) { | |
5be9361c | 5802 | |
1da177e4 | 5803 | case CPU_UP_PREPARE: |
8bb78442 | 5804 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 5805 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
5806 | if (IS_ERR(p)) |
5807 | return NOTIFY_BAD; | |
1da177e4 LT |
5808 | kthread_bind(p, cpu); |
5809 | /* Must be high prio: stop_machine expects to yield to it. */ | |
5810 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 5811 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 | 5812 | task_rq_unlock(rq, &flags); |
371cbb38 | 5813 | get_task_struct(p); |
1da177e4 | 5814 | cpu_rq(cpu)->migration_thread = p; |
a468d389 | 5815 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5816 | break; |
48f24c4d | 5817 | |
1da177e4 | 5818 | case CPU_ONLINE: |
8bb78442 | 5819 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 5820 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 5821 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
5822 | |
5823 | /* Update our root-domain */ | |
5824 | rq = cpu_rq(cpu); | |
05fa785c | 5825 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5826 | if (rq->rd) { |
c6c4927b | 5827 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5828 | |
5829 | set_rq_online(rq); | |
1f94ef59 | 5830 | } |
05fa785c | 5831 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5832 | break; |
48f24c4d | 5833 | |
1da177e4 LT |
5834 | #ifdef CONFIG_HOTPLUG_CPU |
5835 | case CPU_UP_CANCELED: | |
8bb78442 | 5836 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
5837 | if (!cpu_rq(cpu)->migration_thread) |
5838 | break; | |
41a2d6cf | 5839 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 5840 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 5841 | cpumask_any(cpu_online_mask)); |
1da177e4 | 5842 | kthread_stop(cpu_rq(cpu)->migration_thread); |
371cbb38 | 5843 | put_task_struct(cpu_rq(cpu)->migration_thread); |
1da177e4 LT |
5844 | cpu_rq(cpu)->migration_thread = NULL; |
5845 | break; | |
48f24c4d | 5846 | |
1da177e4 | 5847 | case CPU_DEAD: |
8bb78442 | 5848 | case CPU_DEAD_FROZEN: |
1da177e4 LT |
5849 | migrate_live_tasks(cpu); |
5850 | rq = cpu_rq(cpu); | |
5851 | kthread_stop(rq->migration_thread); | |
371cbb38 | 5852 | put_task_struct(rq->migration_thread); |
1da177e4 LT |
5853 | rq->migration_thread = NULL; |
5854 | /* Idle task back to normal (off runqueue, low prio) */ | |
05fa785c | 5855 | raw_spin_lock_irq(&rq->lock); |
2e1cb74a | 5856 | deactivate_task(rq, rq->idle, 0); |
dd41f596 IM |
5857 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
5858 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 5859 | migrate_dead_tasks(cpu); |
05fa785c | 5860 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
5861 | migrate_nr_uninterruptible(rq); |
5862 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 5863 | calc_global_load_remove(rq); |
41a2d6cf IM |
5864 | /* |
5865 | * No need to migrate the tasks: it was best-effort if | |
5866 | * they didn't take sched_hotcpu_mutex. Just wake up | |
5867 | * the requestors. | |
5868 | */ | |
05fa785c | 5869 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5870 | while (!list_empty(&rq->migration_queue)) { |
70b97a7f IM |
5871 | struct migration_req *req; |
5872 | ||
1da177e4 | 5873 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 5874 | struct migration_req, list); |
1da177e4 | 5875 | list_del_init(&req->list); |
05fa785c | 5876 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 5877 | complete(&req->done); |
05fa785c | 5878 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5879 | } |
05fa785c | 5880 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 5881 | break; |
57d885fe | 5882 | |
08f503b0 GH |
5883 | case CPU_DYING: |
5884 | case CPU_DYING_FROZEN: | |
57d885fe GH |
5885 | /* Update our root-domain */ |
5886 | rq = cpu_rq(cpu); | |
05fa785c | 5887 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5888 | if (rq->rd) { |
c6c4927b | 5889 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5890 | set_rq_offline(rq); |
57d885fe | 5891 | } |
05fa785c | 5892 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
57d885fe | 5893 | break; |
1da177e4 LT |
5894 | #endif |
5895 | } | |
5896 | return NOTIFY_OK; | |
5897 | } | |
5898 | ||
f38b0820 PM |
5899 | /* |
5900 | * Register at high priority so that task migration (migrate_all_tasks) | |
5901 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5902 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5903 | */ |
26c2143b | 5904 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
5905 | .notifier_call = migration_call, |
5906 | .priority = 10 | |
5907 | }; | |
5908 | ||
7babe8db | 5909 | static int __init migration_init(void) |
1da177e4 LT |
5910 | { |
5911 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5912 | int err; |
48f24c4d IM |
5913 | |
5914 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
5915 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5916 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5917 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5918 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5919 | |
a004cd42 | 5920 | return 0; |
1da177e4 | 5921 | } |
7babe8db | 5922 | early_initcall(migration_init); |
1da177e4 LT |
5923 | #endif |
5924 | ||
5925 | #ifdef CONFIG_SMP | |
476f3534 | 5926 | |
3e9830dc | 5927 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5928 | |
f6630114 MT |
5929 | static __read_mostly int sched_domain_debug_enabled; |
5930 | ||
5931 | static int __init sched_domain_debug_setup(char *str) | |
5932 | { | |
5933 | sched_domain_debug_enabled = 1; | |
5934 | ||
5935 | return 0; | |
5936 | } | |
5937 | early_param("sched_debug", sched_domain_debug_setup); | |
5938 | ||
7c16ec58 | 5939 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5940 | struct cpumask *groupmask) |
1da177e4 | 5941 | { |
4dcf6aff | 5942 | struct sched_group *group = sd->groups; |
434d53b0 | 5943 | char str[256]; |
1da177e4 | 5944 | |
968ea6d8 | 5945 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5946 | cpumask_clear(groupmask); |
4dcf6aff IM |
5947 | |
5948 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5949 | ||
5950 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5951 | printk("does not load-balance\n"); |
4dcf6aff | 5952 | if (sd->parent) |
3df0fc5b PZ |
5953 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5954 | " has parent"); | |
4dcf6aff | 5955 | return -1; |
41c7ce9a NP |
5956 | } |
5957 | ||
3df0fc5b | 5958 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5959 | |
758b2cdc | 5960 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5961 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5962 | "CPU%d\n", cpu); | |
4dcf6aff | 5963 | } |
758b2cdc | 5964 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5965 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5966 | " CPU%d\n", cpu); | |
4dcf6aff | 5967 | } |
1da177e4 | 5968 | |
4dcf6aff | 5969 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5970 | do { |
4dcf6aff | 5971 | if (!group) { |
3df0fc5b PZ |
5972 | printk("\n"); |
5973 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5974 | break; |
5975 | } | |
5976 | ||
18a3885f | 5977 | if (!group->cpu_power) { |
3df0fc5b PZ |
5978 | printk(KERN_CONT "\n"); |
5979 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
5980 | "set\n"); | |
4dcf6aff IM |
5981 | break; |
5982 | } | |
1da177e4 | 5983 | |
758b2cdc | 5984 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5985 | printk(KERN_CONT "\n"); |
5986 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5987 | break; |
5988 | } | |
1da177e4 | 5989 | |
758b2cdc | 5990 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
5991 | printk(KERN_CONT "\n"); |
5992 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5993 | break; |
5994 | } | |
1da177e4 | 5995 | |
758b2cdc | 5996 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5997 | |
968ea6d8 | 5998 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5999 | |
3df0fc5b | 6000 | printk(KERN_CONT " %s", str); |
18a3885f | 6001 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
3df0fc5b PZ |
6002 | printk(KERN_CONT " (cpu_power = %d)", |
6003 | group->cpu_power); | |
381512cf | 6004 | } |
1da177e4 | 6005 | |
4dcf6aff IM |
6006 | group = group->next; |
6007 | } while (group != sd->groups); | |
3df0fc5b | 6008 | printk(KERN_CONT "\n"); |
1da177e4 | 6009 | |
758b2cdc | 6010 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 6011 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6012 | |
758b2cdc RR |
6013 | if (sd->parent && |
6014 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
6015 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6016 | "of domain->span\n"); | |
4dcf6aff IM |
6017 | return 0; |
6018 | } | |
1da177e4 | 6019 | |
4dcf6aff IM |
6020 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6021 | { | |
d5dd3db1 | 6022 | cpumask_var_t groupmask; |
4dcf6aff | 6023 | int level = 0; |
1da177e4 | 6024 | |
f6630114 MT |
6025 | if (!sched_domain_debug_enabled) |
6026 | return; | |
6027 | ||
4dcf6aff IM |
6028 | if (!sd) { |
6029 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6030 | return; | |
6031 | } | |
1da177e4 | 6032 | |
4dcf6aff IM |
6033 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6034 | ||
d5dd3db1 | 6035 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
6036 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
6037 | return; | |
6038 | } | |
6039 | ||
4dcf6aff | 6040 | for (;;) { |
7c16ec58 | 6041 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 6042 | break; |
1da177e4 LT |
6043 | level++; |
6044 | sd = sd->parent; | |
33859f7f | 6045 | if (!sd) |
4dcf6aff IM |
6046 | break; |
6047 | } | |
d5dd3db1 | 6048 | free_cpumask_var(groupmask); |
1da177e4 | 6049 | } |
6d6bc0ad | 6050 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6051 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6052 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6053 | |
1a20ff27 | 6054 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6055 | { |
758b2cdc | 6056 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6057 | return 1; |
6058 | ||
6059 | /* Following flags need at least 2 groups */ | |
6060 | if (sd->flags & (SD_LOAD_BALANCE | | |
6061 | SD_BALANCE_NEWIDLE | | |
6062 | SD_BALANCE_FORK | | |
89c4710e SS |
6063 | SD_BALANCE_EXEC | |
6064 | SD_SHARE_CPUPOWER | | |
6065 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6066 | if (sd->groups != sd->groups->next) |
6067 | return 0; | |
6068 | } | |
6069 | ||
6070 | /* Following flags don't use groups */ | |
c88d5910 | 6071 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
6072 | return 0; |
6073 | ||
6074 | return 1; | |
6075 | } | |
6076 | ||
48f24c4d IM |
6077 | static int |
6078 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6079 | { |
6080 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6081 | ||
6082 | if (sd_degenerate(parent)) | |
6083 | return 1; | |
6084 | ||
758b2cdc | 6085 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6086 | return 0; |
6087 | ||
245af2c7 SS |
6088 | /* Flags needing groups don't count if only 1 group in parent */ |
6089 | if (parent->groups == parent->groups->next) { | |
6090 | pflags &= ~(SD_LOAD_BALANCE | | |
6091 | SD_BALANCE_NEWIDLE | | |
6092 | SD_BALANCE_FORK | | |
89c4710e SS |
6093 | SD_BALANCE_EXEC | |
6094 | SD_SHARE_CPUPOWER | | |
6095 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6096 | if (nr_node_ids == 1) |
6097 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6098 | } |
6099 | if (~cflags & pflags) | |
6100 | return 0; | |
6101 | ||
6102 | return 1; | |
6103 | } | |
6104 | ||
c6c4927b RR |
6105 | static void free_rootdomain(struct root_domain *rd) |
6106 | { | |
047106ad PZ |
6107 | synchronize_sched(); |
6108 | ||
68e74568 RR |
6109 | cpupri_cleanup(&rd->cpupri); |
6110 | ||
c6c4927b RR |
6111 | free_cpumask_var(rd->rto_mask); |
6112 | free_cpumask_var(rd->online); | |
6113 | free_cpumask_var(rd->span); | |
6114 | kfree(rd); | |
6115 | } | |
6116 | ||
57d885fe GH |
6117 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6118 | { | |
a0490fa3 | 6119 | struct root_domain *old_rd = NULL; |
57d885fe | 6120 | unsigned long flags; |
57d885fe | 6121 | |
05fa785c | 6122 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6123 | |
6124 | if (rq->rd) { | |
a0490fa3 | 6125 | old_rd = rq->rd; |
57d885fe | 6126 | |
c6c4927b | 6127 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6128 | set_rq_offline(rq); |
57d885fe | 6129 | |
c6c4927b | 6130 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6131 | |
a0490fa3 IM |
6132 | /* |
6133 | * If we dont want to free the old_rt yet then | |
6134 | * set old_rd to NULL to skip the freeing later | |
6135 | * in this function: | |
6136 | */ | |
6137 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6138 | old_rd = NULL; | |
57d885fe GH |
6139 | } |
6140 | ||
6141 | atomic_inc(&rd->refcount); | |
6142 | rq->rd = rd; | |
6143 | ||
c6c4927b | 6144 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6145 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6146 | set_rq_online(rq); |
57d885fe | 6147 | |
05fa785c | 6148 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6149 | |
6150 | if (old_rd) | |
6151 | free_rootdomain(old_rd); | |
57d885fe GH |
6152 | } |
6153 | ||
fd5e1b5d | 6154 | static int init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe | 6155 | { |
36b7b6d4 PE |
6156 | gfp_t gfp = GFP_KERNEL; |
6157 | ||
57d885fe GH |
6158 | memset(rd, 0, sizeof(*rd)); |
6159 | ||
36b7b6d4 PE |
6160 | if (bootmem) |
6161 | gfp = GFP_NOWAIT; | |
c6c4927b | 6162 | |
36b7b6d4 | 6163 | if (!alloc_cpumask_var(&rd->span, gfp)) |
0c910d28 | 6164 | goto out; |
36b7b6d4 | 6165 | if (!alloc_cpumask_var(&rd->online, gfp)) |
c6c4927b | 6166 | goto free_span; |
36b7b6d4 | 6167 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) |
c6c4927b | 6168 | goto free_online; |
6e0534f2 | 6169 | |
0fb53029 | 6170 | if (cpupri_init(&rd->cpupri, bootmem) != 0) |
68e74568 | 6171 | goto free_rto_mask; |
c6c4927b | 6172 | return 0; |
6e0534f2 | 6173 | |
68e74568 RR |
6174 | free_rto_mask: |
6175 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6176 | free_online: |
6177 | free_cpumask_var(rd->online); | |
6178 | free_span: | |
6179 | free_cpumask_var(rd->span); | |
0c910d28 | 6180 | out: |
c6c4927b | 6181 | return -ENOMEM; |
57d885fe GH |
6182 | } |
6183 | ||
6184 | static void init_defrootdomain(void) | |
6185 | { | |
c6c4927b RR |
6186 | init_rootdomain(&def_root_domain, true); |
6187 | ||
57d885fe GH |
6188 | atomic_set(&def_root_domain.refcount, 1); |
6189 | } | |
6190 | ||
dc938520 | 6191 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6192 | { |
6193 | struct root_domain *rd; | |
6194 | ||
6195 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6196 | if (!rd) | |
6197 | return NULL; | |
6198 | ||
c6c4927b RR |
6199 | if (init_rootdomain(rd, false) != 0) { |
6200 | kfree(rd); | |
6201 | return NULL; | |
6202 | } | |
57d885fe GH |
6203 | |
6204 | return rd; | |
6205 | } | |
6206 | ||
1da177e4 | 6207 | /* |
0eab9146 | 6208 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
6209 | * hold the hotplug lock. |
6210 | */ | |
0eab9146 IM |
6211 | static void |
6212 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 6213 | { |
70b97a7f | 6214 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
6215 | struct sched_domain *tmp; |
6216 | ||
6217 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 6218 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
6219 | struct sched_domain *parent = tmp->parent; |
6220 | if (!parent) | |
6221 | break; | |
f29c9b1c | 6222 | |
1a848870 | 6223 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 6224 | tmp->parent = parent->parent; |
1a848870 SS |
6225 | if (parent->parent) |
6226 | parent->parent->child = tmp; | |
f29c9b1c LZ |
6227 | } else |
6228 | tmp = tmp->parent; | |
245af2c7 SS |
6229 | } |
6230 | ||
1a848870 | 6231 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 6232 | sd = sd->parent; |
1a848870 SS |
6233 | if (sd) |
6234 | sd->child = NULL; | |
6235 | } | |
1da177e4 LT |
6236 | |
6237 | sched_domain_debug(sd, cpu); | |
6238 | ||
57d885fe | 6239 | rq_attach_root(rq, rd); |
674311d5 | 6240 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
6241 | } |
6242 | ||
6243 | /* cpus with isolated domains */ | |
dcc30a35 | 6244 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
6245 | |
6246 | /* Setup the mask of cpus configured for isolated domains */ | |
6247 | static int __init isolated_cpu_setup(char *str) | |
6248 | { | |
bdddd296 | 6249 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 6250 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
6251 | return 1; |
6252 | } | |
6253 | ||
8927f494 | 6254 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
6255 | |
6256 | /* | |
6711cab4 SS |
6257 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
6258 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
6259 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
6260 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
6261 | * |
6262 | * init_sched_build_groups will build a circular linked list of the groups | |
6263 | * covered by the given span, and will set each group's ->cpumask correctly, | |
6264 | * and ->cpu_power to 0. | |
6265 | */ | |
a616058b | 6266 | static void |
96f874e2 RR |
6267 | init_sched_build_groups(const struct cpumask *span, |
6268 | const struct cpumask *cpu_map, | |
6269 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 6270 | struct sched_group **sg, |
96f874e2 RR |
6271 | struct cpumask *tmpmask), |
6272 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
6273 | { |
6274 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
6275 | int i; |
6276 | ||
96f874e2 | 6277 | cpumask_clear(covered); |
7c16ec58 | 6278 | |
abcd083a | 6279 | for_each_cpu(i, span) { |
6711cab4 | 6280 | struct sched_group *sg; |
7c16ec58 | 6281 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
6282 | int j; |
6283 | ||
758b2cdc | 6284 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
6285 | continue; |
6286 | ||
758b2cdc | 6287 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 6288 | sg->cpu_power = 0; |
1da177e4 | 6289 | |
abcd083a | 6290 | for_each_cpu(j, span) { |
7c16ec58 | 6291 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
6292 | continue; |
6293 | ||
96f874e2 | 6294 | cpumask_set_cpu(j, covered); |
758b2cdc | 6295 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
6296 | } |
6297 | if (!first) | |
6298 | first = sg; | |
6299 | if (last) | |
6300 | last->next = sg; | |
6301 | last = sg; | |
6302 | } | |
6303 | last->next = first; | |
6304 | } | |
6305 | ||
9c1cfda2 | 6306 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 6307 | |
9c1cfda2 | 6308 | #ifdef CONFIG_NUMA |
198e2f18 | 6309 | |
9c1cfda2 JH |
6310 | /** |
6311 | * find_next_best_node - find the next node to include in a sched_domain | |
6312 | * @node: node whose sched_domain we're building | |
6313 | * @used_nodes: nodes already in the sched_domain | |
6314 | * | |
41a2d6cf | 6315 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
6316 | * finds the closest node not already in the @used_nodes map. |
6317 | * | |
6318 | * Should use nodemask_t. | |
6319 | */ | |
c5f59f08 | 6320 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
6321 | { |
6322 | int i, n, val, min_val, best_node = 0; | |
6323 | ||
6324 | min_val = INT_MAX; | |
6325 | ||
076ac2af | 6326 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 6327 | /* Start at @node */ |
076ac2af | 6328 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
6329 | |
6330 | if (!nr_cpus_node(n)) | |
6331 | continue; | |
6332 | ||
6333 | /* Skip already used nodes */ | |
c5f59f08 | 6334 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
6335 | continue; |
6336 | ||
6337 | /* Simple min distance search */ | |
6338 | val = node_distance(node, n); | |
6339 | ||
6340 | if (val < min_val) { | |
6341 | min_val = val; | |
6342 | best_node = n; | |
6343 | } | |
6344 | } | |
6345 | ||
c5f59f08 | 6346 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
6347 | return best_node; |
6348 | } | |
6349 | ||
6350 | /** | |
6351 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
6352 | * @node: node whose cpumask we're constructing | |
73486722 | 6353 | * @span: resulting cpumask |
9c1cfda2 | 6354 | * |
41a2d6cf | 6355 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
6356 | * should be one that prevents unnecessary balancing, but also spreads tasks |
6357 | * out optimally. | |
6358 | */ | |
96f874e2 | 6359 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 6360 | { |
c5f59f08 | 6361 | nodemask_t used_nodes; |
48f24c4d | 6362 | int i; |
9c1cfda2 | 6363 | |
6ca09dfc | 6364 | cpumask_clear(span); |
c5f59f08 | 6365 | nodes_clear(used_nodes); |
9c1cfda2 | 6366 | |
6ca09dfc | 6367 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 6368 | node_set(node, used_nodes); |
9c1cfda2 JH |
6369 | |
6370 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 6371 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 6372 | |
6ca09dfc | 6373 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 6374 | } |
9c1cfda2 | 6375 | } |
6d6bc0ad | 6376 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 6377 | |
5c45bf27 | 6378 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 6379 | |
6c99e9ad RR |
6380 | /* |
6381 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
6382 | * |
6383 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
6384 | * and struct sched_domain. ) | |
6c99e9ad RR |
6385 | */ |
6386 | struct static_sched_group { | |
6387 | struct sched_group sg; | |
6388 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
6389 | }; | |
6390 | ||
6391 | struct static_sched_domain { | |
6392 | struct sched_domain sd; | |
6393 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
6394 | }; | |
6395 | ||
49a02c51 AH |
6396 | struct s_data { |
6397 | #ifdef CONFIG_NUMA | |
6398 | int sd_allnodes; | |
6399 | cpumask_var_t domainspan; | |
6400 | cpumask_var_t covered; | |
6401 | cpumask_var_t notcovered; | |
6402 | #endif | |
6403 | cpumask_var_t nodemask; | |
6404 | cpumask_var_t this_sibling_map; | |
6405 | cpumask_var_t this_core_map; | |
6406 | cpumask_var_t send_covered; | |
6407 | cpumask_var_t tmpmask; | |
6408 | struct sched_group **sched_group_nodes; | |
6409 | struct root_domain *rd; | |
6410 | }; | |
6411 | ||
2109b99e AH |
6412 | enum s_alloc { |
6413 | sa_sched_groups = 0, | |
6414 | sa_rootdomain, | |
6415 | sa_tmpmask, | |
6416 | sa_send_covered, | |
6417 | sa_this_core_map, | |
6418 | sa_this_sibling_map, | |
6419 | sa_nodemask, | |
6420 | sa_sched_group_nodes, | |
6421 | #ifdef CONFIG_NUMA | |
6422 | sa_notcovered, | |
6423 | sa_covered, | |
6424 | sa_domainspan, | |
6425 | #endif | |
6426 | sa_none, | |
6427 | }; | |
6428 | ||
9c1cfda2 | 6429 | /* |
48f24c4d | 6430 | * SMT sched-domains: |
9c1cfda2 | 6431 | */ |
1da177e4 | 6432 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 6433 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
1871e52c | 6434 | static DEFINE_PER_CPU(struct static_sched_group, sched_groups); |
48f24c4d | 6435 | |
41a2d6cf | 6436 | static int |
96f874e2 RR |
6437 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
6438 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 6439 | { |
6711cab4 | 6440 | if (sg) |
1871e52c | 6441 | *sg = &per_cpu(sched_groups, cpu).sg; |
1da177e4 LT |
6442 | return cpu; |
6443 | } | |
6d6bc0ad | 6444 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 6445 | |
48f24c4d IM |
6446 | /* |
6447 | * multi-core sched-domains: | |
6448 | */ | |
1e9f28fa | 6449 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
6450 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
6451 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 6452 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
6453 | |
6454 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 6455 | static int |
96f874e2 RR |
6456 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6457 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 6458 | { |
6711cab4 | 6459 | int group; |
7c16ec58 | 6460 | |
c69fc56d | 6461 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6462 | group = cpumask_first(mask); |
6711cab4 | 6463 | if (sg) |
6c99e9ad | 6464 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 6465 | return group; |
1e9f28fa SS |
6466 | } |
6467 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 6468 | static int |
96f874e2 RR |
6469 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6470 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 6471 | { |
6711cab4 | 6472 | if (sg) |
6c99e9ad | 6473 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
6474 | return cpu; |
6475 | } | |
6476 | #endif | |
6477 | ||
6c99e9ad RR |
6478 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
6479 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 6480 | |
41a2d6cf | 6481 | static int |
96f874e2 RR |
6482 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
6483 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 6484 | { |
6711cab4 | 6485 | int group; |
48f24c4d | 6486 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 6487 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 6488 | group = cpumask_first(mask); |
1e9f28fa | 6489 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 6490 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6491 | group = cpumask_first(mask); |
1da177e4 | 6492 | #else |
6711cab4 | 6493 | group = cpu; |
1da177e4 | 6494 | #endif |
6711cab4 | 6495 | if (sg) |
6c99e9ad | 6496 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 6497 | return group; |
1da177e4 LT |
6498 | } |
6499 | ||
6500 | #ifdef CONFIG_NUMA | |
1da177e4 | 6501 | /* |
9c1cfda2 JH |
6502 | * The init_sched_build_groups can't handle what we want to do with node |
6503 | * groups, so roll our own. Now each node has its own list of groups which | |
6504 | * gets dynamically allocated. | |
1da177e4 | 6505 | */ |
62ea9ceb | 6506 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 6507 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 6508 | |
62ea9ceb | 6509 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 6510 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 6511 | |
96f874e2 RR |
6512 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
6513 | struct sched_group **sg, | |
6514 | struct cpumask *nodemask) | |
9c1cfda2 | 6515 | { |
6711cab4 SS |
6516 | int group; |
6517 | ||
6ca09dfc | 6518 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 6519 | group = cpumask_first(nodemask); |
6711cab4 SS |
6520 | |
6521 | if (sg) | |
6c99e9ad | 6522 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 6523 | return group; |
1da177e4 | 6524 | } |
6711cab4 | 6525 | |
08069033 SS |
6526 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
6527 | { | |
6528 | struct sched_group *sg = group_head; | |
6529 | int j; | |
6530 | ||
6531 | if (!sg) | |
6532 | return; | |
3a5c359a | 6533 | do { |
758b2cdc | 6534 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 6535 | struct sched_domain *sd; |
08069033 | 6536 | |
6c99e9ad | 6537 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 6538 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
6539 | /* |
6540 | * Only add "power" once for each | |
6541 | * physical package. | |
6542 | */ | |
6543 | continue; | |
6544 | } | |
08069033 | 6545 | |
18a3885f | 6546 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
6547 | } |
6548 | sg = sg->next; | |
6549 | } while (sg != group_head); | |
08069033 | 6550 | } |
0601a88d AH |
6551 | |
6552 | static int build_numa_sched_groups(struct s_data *d, | |
6553 | const struct cpumask *cpu_map, int num) | |
6554 | { | |
6555 | struct sched_domain *sd; | |
6556 | struct sched_group *sg, *prev; | |
6557 | int n, j; | |
6558 | ||
6559 | cpumask_clear(d->covered); | |
6560 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
6561 | if (cpumask_empty(d->nodemask)) { | |
6562 | d->sched_group_nodes[num] = NULL; | |
6563 | goto out; | |
6564 | } | |
6565 | ||
6566 | sched_domain_node_span(num, d->domainspan); | |
6567 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
6568 | ||
6569 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6570 | GFP_KERNEL, num); | |
6571 | if (!sg) { | |
3df0fc5b PZ |
6572 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", |
6573 | num); | |
0601a88d AH |
6574 | return -ENOMEM; |
6575 | } | |
6576 | d->sched_group_nodes[num] = sg; | |
6577 | ||
6578 | for_each_cpu(j, d->nodemask) { | |
6579 | sd = &per_cpu(node_domains, j).sd; | |
6580 | sd->groups = sg; | |
6581 | } | |
6582 | ||
18a3885f | 6583 | sg->cpu_power = 0; |
0601a88d AH |
6584 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
6585 | sg->next = sg; | |
6586 | cpumask_or(d->covered, d->covered, d->nodemask); | |
6587 | ||
6588 | prev = sg; | |
6589 | for (j = 0; j < nr_node_ids; j++) { | |
6590 | n = (num + j) % nr_node_ids; | |
6591 | cpumask_complement(d->notcovered, d->covered); | |
6592 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
6593 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
6594 | if (cpumask_empty(d->tmpmask)) | |
6595 | break; | |
6596 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
6597 | if (cpumask_empty(d->tmpmask)) | |
6598 | continue; | |
6599 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6600 | GFP_KERNEL, num); | |
6601 | if (!sg) { | |
3df0fc5b PZ |
6602 | printk(KERN_WARNING |
6603 | "Can not alloc domain group for node %d\n", j); | |
0601a88d AH |
6604 | return -ENOMEM; |
6605 | } | |
18a3885f | 6606 | sg->cpu_power = 0; |
0601a88d AH |
6607 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
6608 | sg->next = prev->next; | |
6609 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
6610 | prev->next = sg; | |
6611 | prev = sg; | |
6612 | } | |
6613 | out: | |
6614 | return 0; | |
6615 | } | |
6d6bc0ad | 6616 | #endif /* CONFIG_NUMA */ |
1da177e4 | 6617 | |
a616058b | 6618 | #ifdef CONFIG_NUMA |
51888ca2 | 6619 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
6620 | static void free_sched_groups(const struct cpumask *cpu_map, |
6621 | struct cpumask *nodemask) | |
51888ca2 | 6622 | { |
a616058b | 6623 | int cpu, i; |
51888ca2 | 6624 | |
abcd083a | 6625 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
6626 | struct sched_group **sched_group_nodes |
6627 | = sched_group_nodes_bycpu[cpu]; | |
6628 | ||
51888ca2 SV |
6629 | if (!sched_group_nodes) |
6630 | continue; | |
6631 | ||
076ac2af | 6632 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
6633 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
6634 | ||
6ca09dfc | 6635 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 6636 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
6637 | continue; |
6638 | ||
6639 | if (sg == NULL) | |
6640 | continue; | |
6641 | sg = sg->next; | |
6642 | next_sg: | |
6643 | oldsg = sg; | |
6644 | sg = sg->next; | |
6645 | kfree(oldsg); | |
6646 | if (oldsg != sched_group_nodes[i]) | |
6647 | goto next_sg; | |
6648 | } | |
6649 | kfree(sched_group_nodes); | |
6650 | sched_group_nodes_bycpu[cpu] = NULL; | |
6651 | } | |
51888ca2 | 6652 | } |
6d6bc0ad | 6653 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
6654 | static void free_sched_groups(const struct cpumask *cpu_map, |
6655 | struct cpumask *nodemask) | |
a616058b SS |
6656 | { |
6657 | } | |
6d6bc0ad | 6658 | #endif /* CONFIG_NUMA */ |
51888ca2 | 6659 | |
89c4710e SS |
6660 | /* |
6661 | * Initialize sched groups cpu_power. | |
6662 | * | |
6663 | * cpu_power indicates the capacity of sched group, which is used while | |
6664 | * distributing the load between different sched groups in a sched domain. | |
6665 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
6666 | * there are asymmetries in the topology. If there are asymmetries, group | |
6667 | * having more cpu_power will pickup more load compared to the group having | |
6668 | * less cpu_power. | |
89c4710e SS |
6669 | */ |
6670 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
6671 | { | |
6672 | struct sched_domain *child; | |
6673 | struct sched_group *group; | |
f93e65c1 PZ |
6674 | long power; |
6675 | int weight; | |
89c4710e SS |
6676 | |
6677 | WARN_ON(!sd || !sd->groups); | |
6678 | ||
13318a71 | 6679 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
6680 | return; |
6681 | ||
6682 | child = sd->child; | |
6683 | ||
18a3885f | 6684 | sd->groups->cpu_power = 0; |
5517d86b | 6685 | |
f93e65c1 PZ |
6686 | if (!child) { |
6687 | power = SCHED_LOAD_SCALE; | |
6688 | weight = cpumask_weight(sched_domain_span(sd)); | |
6689 | /* | |
6690 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
6691 | * Usually multiple threads get a better yield out of |
6692 | * that one core than a single thread would have, | |
6693 | * reflect that in sd->smt_gain. | |
f93e65c1 | 6694 | */ |
a52bfd73 PZ |
6695 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
6696 | power *= sd->smt_gain; | |
f93e65c1 | 6697 | power /= weight; |
a52bfd73 PZ |
6698 | power >>= SCHED_LOAD_SHIFT; |
6699 | } | |
18a3885f | 6700 | sd->groups->cpu_power += power; |
89c4710e SS |
6701 | return; |
6702 | } | |
6703 | ||
89c4710e | 6704 | /* |
f93e65c1 | 6705 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
6706 | */ |
6707 | group = child->groups; | |
6708 | do { | |
18a3885f | 6709 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
6710 | group = group->next; |
6711 | } while (group != child->groups); | |
6712 | } | |
6713 | ||
7c16ec58 MT |
6714 | /* |
6715 | * Initializers for schedule domains | |
6716 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
6717 | */ | |
6718 | ||
a5d8c348 IM |
6719 | #ifdef CONFIG_SCHED_DEBUG |
6720 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
6721 | #else | |
6722 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
6723 | #endif | |
6724 | ||
7c16ec58 | 6725 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 6726 | |
7c16ec58 MT |
6727 | #define SD_INIT_FUNC(type) \ |
6728 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
6729 | { \ | |
6730 | memset(sd, 0, sizeof(*sd)); \ | |
6731 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 6732 | sd->level = SD_LV_##type; \ |
a5d8c348 | 6733 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
6734 | } |
6735 | ||
6736 | SD_INIT_FUNC(CPU) | |
6737 | #ifdef CONFIG_NUMA | |
6738 | SD_INIT_FUNC(ALLNODES) | |
6739 | SD_INIT_FUNC(NODE) | |
6740 | #endif | |
6741 | #ifdef CONFIG_SCHED_SMT | |
6742 | SD_INIT_FUNC(SIBLING) | |
6743 | #endif | |
6744 | #ifdef CONFIG_SCHED_MC | |
6745 | SD_INIT_FUNC(MC) | |
6746 | #endif | |
6747 | ||
1d3504fc HS |
6748 | static int default_relax_domain_level = -1; |
6749 | ||
6750 | static int __init setup_relax_domain_level(char *str) | |
6751 | { | |
30e0e178 LZ |
6752 | unsigned long val; |
6753 | ||
6754 | val = simple_strtoul(str, NULL, 0); | |
6755 | if (val < SD_LV_MAX) | |
6756 | default_relax_domain_level = val; | |
6757 | ||
1d3504fc HS |
6758 | return 1; |
6759 | } | |
6760 | __setup("relax_domain_level=", setup_relax_domain_level); | |
6761 | ||
6762 | static void set_domain_attribute(struct sched_domain *sd, | |
6763 | struct sched_domain_attr *attr) | |
6764 | { | |
6765 | int request; | |
6766 | ||
6767 | if (!attr || attr->relax_domain_level < 0) { | |
6768 | if (default_relax_domain_level < 0) | |
6769 | return; | |
6770 | else | |
6771 | request = default_relax_domain_level; | |
6772 | } else | |
6773 | request = attr->relax_domain_level; | |
6774 | if (request < sd->level) { | |
6775 | /* turn off idle balance on this domain */ | |
c88d5910 | 6776 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6777 | } else { |
6778 | /* turn on idle balance on this domain */ | |
c88d5910 | 6779 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6780 | } |
6781 | } | |
6782 | ||
2109b99e AH |
6783 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
6784 | const struct cpumask *cpu_map) | |
6785 | { | |
6786 | switch (what) { | |
6787 | case sa_sched_groups: | |
6788 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
6789 | d->sched_group_nodes = NULL; | |
6790 | case sa_rootdomain: | |
6791 | free_rootdomain(d->rd); /* fall through */ | |
6792 | case sa_tmpmask: | |
6793 | free_cpumask_var(d->tmpmask); /* fall through */ | |
6794 | case sa_send_covered: | |
6795 | free_cpumask_var(d->send_covered); /* fall through */ | |
6796 | case sa_this_core_map: | |
6797 | free_cpumask_var(d->this_core_map); /* fall through */ | |
6798 | case sa_this_sibling_map: | |
6799 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
6800 | case sa_nodemask: | |
6801 | free_cpumask_var(d->nodemask); /* fall through */ | |
6802 | case sa_sched_group_nodes: | |
d1b55138 | 6803 | #ifdef CONFIG_NUMA |
2109b99e AH |
6804 | kfree(d->sched_group_nodes); /* fall through */ |
6805 | case sa_notcovered: | |
6806 | free_cpumask_var(d->notcovered); /* fall through */ | |
6807 | case sa_covered: | |
6808 | free_cpumask_var(d->covered); /* fall through */ | |
6809 | case sa_domainspan: | |
6810 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 6811 | #endif |
2109b99e AH |
6812 | case sa_none: |
6813 | break; | |
6814 | } | |
6815 | } | |
3404c8d9 | 6816 | |
2109b99e AH |
6817 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
6818 | const struct cpumask *cpu_map) | |
6819 | { | |
3404c8d9 | 6820 | #ifdef CONFIG_NUMA |
2109b99e AH |
6821 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
6822 | return sa_none; | |
6823 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
6824 | return sa_domainspan; | |
6825 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
6826 | return sa_covered; | |
6827 | /* Allocate the per-node list of sched groups */ | |
6828 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
6829 | sizeof(struct sched_group *), GFP_KERNEL); | |
6830 | if (!d->sched_group_nodes) { | |
3df0fc5b | 6831 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 6832 | return sa_notcovered; |
d1b55138 | 6833 | } |
2109b99e | 6834 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 6835 | #endif |
2109b99e AH |
6836 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
6837 | return sa_sched_group_nodes; | |
6838 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
6839 | return sa_nodemask; | |
6840 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
6841 | return sa_this_sibling_map; | |
6842 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
6843 | return sa_this_core_map; | |
6844 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
6845 | return sa_send_covered; | |
6846 | d->rd = alloc_rootdomain(); | |
6847 | if (!d->rd) { | |
3df0fc5b | 6848 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 6849 | return sa_tmpmask; |
57d885fe | 6850 | } |
2109b99e AH |
6851 | return sa_rootdomain; |
6852 | } | |
57d885fe | 6853 | |
7f4588f3 AH |
6854 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
6855 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
6856 | { | |
6857 | struct sched_domain *sd = NULL; | |
7c16ec58 | 6858 | #ifdef CONFIG_NUMA |
7f4588f3 | 6859 | struct sched_domain *parent; |
1da177e4 | 6860 | |
7f4588f3 AH |
6861 | d->sd_allnodes = 0; |
6862 | if (cpumask_weight(cpu_map) > | |
6863 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
6864 | sd = &per_cpu(allnodes_domains, i).sd; | |
6865 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 6866 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
6867 | cpumask_copy(sched_domain_span(sd), cpu_map); |
6868 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6869 | d->sd_allnodes = 1; | |
6870 | } | |
6871 | parent = sd; | |
6872 | ||
6873 | sd = &per_cpu(node_domains, i).sd; | |
6874 | SD_INIT(sd, NODE); | |
6875 | set_domain_attribute(sd, attr); | |
6876 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
6877 | sd->parent = parent; | |
6878 | if (parent) | |
6879 | parent->child = sd; | |
6880 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 6881 | #endif |
7f4588f3 AH |
6882 | return sd; |
6883 | } | |
1da177e4 | 6884 | |
87cce662 AH |
6885 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
6886 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6887 | struct sched_domain *parent, int i) | |
6888 | { | |
6889 | struct sched_domain *sd; | |
6890 | sd = &per_cpu(phys_domains, i).sd; | |
6891 | SD_INIT(sd, CPU); | |
6892 | set_domain_attribute(sd, attr); | |
6893 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
6894 | sd->parent = parent; | |
6895 | if (parent) | |
6896 | parent->child = sd; | |
6897 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6898 | return sd; | |
6899 | } | |
1da177e4 | 6900 | |
410c4081 AH |
6901 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
6902 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6903 | struct sched_domain *parent, int i) | |
6904 | { | |
6905 | struct sched_domain *sd = parent; | |
1e9f28fa | 6906 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
6907 | sd = &per_cpu(core_domains, i).sd; |
6908 | SD_INIT(sd, MC); | |
6909 | set_domain_attribute(sd, attr); | |
6910 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
6911 | sd->parent = parent; | |
6912 | parent->child = sd; | |
6913 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 6914 | #endif |
410c4081 AH |
6915 | return sd; |
6916 | } | |
1e9f28fa | 6917 | |
d8173535 AH |
6918 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
6919 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6920 | struct sched_domain *parent, int i) | |
6921 | { | |
6922 | struct sched_domain *sd = parent; | |
1da177e4 | 6923 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
6924 | sd = &per_cpu(cpu_domains, i).sd; |
6925 | SD_INIT(sd, SIBLING); | |
6926 | set_domain_attribute(sd, attr); | |
6927 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
6928 | sd->parent = parent; | |
6929 | parent->child = sd; | |
6930 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 6931 | #endif |
d8173535 AH |
6932 | return sd; |
6933 | } | |
1da177e4 | 6934 | |
0e8e85c9 AH |
6935 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
6936 | const struct cpumask *cpu_map, int cpu) | |
6937 | { | |
6938 | switch (l) { | |
1da177e4 | 6939 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
6940 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
6941 | cpumask_and(d->this_sibling_map, cpu_map, | |
6942 | topology_thread_cpumask(cpu)); | |
6943 | if (cpu == cpumask_first(d->this_sibling_map)) | |
6944 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
6945 | &cpu_to_cpu_group, | |
6946 | d->send_covered, d->tmpmask); | |
6947 | break; | |
1da177e4 | 6948 | #endif |
1e9f28fa | 6949 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
6950 | case SD_LV_MC: /* set up multi-core groups */ |
6951 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
6952 | if (cpu == cpumask_first(d->this_core_map)) | |
6953 | init_sched_build_groups(d->this_core_map, cpu_map, | |
6954 | &cpu_to_core_group, | |
6955 | d->send_covered, d->tmpmask); | |
6956 | break; | |
1e9f28fa | 6957 | #endif |
86548096 AH |
6958 | case SD_LV_CPU: /* set up physical groups */ |
6959 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
6960 | if (!cpumask_empty(d->nodemask)) | |
6961 | init_sched_build_groups(d->nodemask, cpu_map, | |
6962 | &cpu_to_phys_group, | |
6963 | d->send_covered, d->tmpmask); | |
6964 | break; | |
1da177e4 | 6965 | #ifdef CONFIG_NUMA |
de616e36 AH |
6966 | case SD_LV_ALLNODES: |
6967 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
6968 | d->send_covered, d->tmpmask); | |
6969 | break; | |
6970 | #endif | |
0e8e85c9 AH |
6971 | default: |
6972 | break; | |
7c16ec58 | 6973 | } |
0e8e85c9 | 6974 | } |
9c1cfda2 | 6975 | |
2109b99e AH |
6976 | /* |
6977 | * Build sched domains for a given set of cpus and attach the sched domains | |
6978 | * to the individual cpus | |
6979 | */ | |
6980 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
6981 | struct sched_domain_attr *attr) | |
6982 | { | |
6983 | enum s_alloc alloc_state = sa_none; | |
6984 | struct s_data d; | |
294b0c96 | 6985 | struct sched_domain *sd; |
2109b99e | 6986 | int i; |
7c16ec58 | 6987 | #ifdef CONFIG_NUMA |
2109b99e | 6988 | d.sd_allnodes = 0; |
7c16ec58 | 6989 | #endif |
9c1cfda2 | 6990 | |
2109b99e AH |
6991 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6992 | if (alloc_state != sa_rootdomain) | |
6993 | goto error; | |
6994 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 6995 | |
1da177e4 | 6996 | /* |
1a20ff27 | 6997 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 6998 | */ |
abcd083a | 6999 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
7000 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
7001 | cpu_map); | |
9761eea8 | 7002 | |
7f4588f3 | 7003 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 7004 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 7005 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 7006 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 7007 | } |
9c1cfda2 | 7008 | |
abcd083a | 7009 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 7010 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 7011 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 7012 | } |
9c1cfda2 | 7013 | |
1da177e4 | 7014 | /* Set up physical groups */ |
86548096 AH |
7015 | for (i = 0; i < nr_node_ids; i++) |
7016 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 7017 | |
1da177e4 LT |
7018 | #ifdef CONFIG_NUMA |
7019 | /* Set up node groups */ | |
de616e36 AH |
7020 | if (d.sd_allnodes) |
7021 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 7022 | |
0601a88d AH |
7023 | for (i = 0; i < nr_node_ids; i++) |
7024 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 7025 | goto error; |
1da177e4 LT |
7026 | #endif |
7027 | ||
7028 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 7029 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 7030 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7031 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 7032 | init_sched_groups_power(i, sd); |
5c45bf27 | 7033 | } |
1da177e4 | 7034 | #endif |
1e9f28fa | 7035 | #ifdef CONFIG_SCHED_MC |
abcd083a | 7036 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7037 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 7038 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
7039 | } |
7040 | #endif | |
1e9f28fa | 7041 | |
abcd083a | 7042 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7043 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 7044 | init_sched_groups_power(i, sd); |
1da177e4 LT |
7045 | } |
7046 | ||
9c1cfda2 | 7047 | #ifdef CONFIG_NUMA |
076ac2af | 7048 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 7049 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 7050 | |
49a02c51 | 7051 | if (d.sd_allnodes) { |
6711cab4 | 7052 | struct sched_group *sg; |
f712c0c7 | 7053 | |
96f874e2 | 7054 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 7055 | d.tmpmask); |
f712c0c7 SS |
7056 | init_numa_sched_groups_power(sg); |
7057 | } | |
9c1cfda2 JH |
7058 | #endif |
7059 | ||
1da177e4 | 7060 | /* Attach the domains */ |
abcd083a | 7061 | for_each_cpu(i, cpu_map) { |
1da177e4 | 7062 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 7063 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 7064 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 7065 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 7066 | #else |
6c99e9ad | 7067 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 7068 | #endif |
49a02c51 | 7069 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 7070 | } |
51888ca2 | 7071 | |
2109b99e AH |
7072 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
7073 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
7074 | return 0; | |
51888ca2 | 7075 | |
51888ca2 | 7076 | error: |
2109b99e AH |
7077 | __free_domain_allocs(&d, alloc_state, cpu_map); |
7078 | return -ENOMEM; | |
1da177e4 | 7079 | } |
029190c5 | 7080 | |
96f874e2 | 7081 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
7082 | { |
7083 | return __build_sched_domains(cpu_map, NULL); | |
7084 | } | |
7085 | ||
acc3f5d7 | 7086 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 7087 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7088 | static struct sched_domain_attr *dattr_cur; |
7089 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7090 | |
7091 | /* | |
7092 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7093 | * cpumask) fails, then fallback to a single sched domain, |
7094 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7095 | */ |
4212823f | 7096 | static cpumask_var_t fallback_doms; |
029190c5 | 7097 | |
ee79d1bd HC |
7098 | /* |
7099 | * arch_update_cpu_topology lets virtualized architectures update the | |
7100 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7101 | * or 0 if it stayed the same. | |
7102 | */ | |
7103 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7104 | { |
ee79d1bd | 7105 | return 0; |
22e52b07 HC |
7106 | } |
7107 | ||
acc3f5d7 RR |
7108 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7109 | { | |
7110 | int i; | |
7111 | cpumask_var_t *doms; | |
7112 | ||
7113 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7114 | if (!doms) | |
7115 | return NULL; | |
7116 | for (i = 0; i < ndoms; i++) { | |
7117 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7118 | free_sched_domains(doms, i); | |
7119 | return NULL; | |
7120 | } | |
7121 | } | |
7122 | return doms; | |
7123 | } | |
7124 | ||
7125 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7126 | { | |
7127 | unsigned int i; | |
7128 | for (i = 0; i < ndoms; i++) | |
7129 | free_cpumask_var(doms[i]); | |
7130 | kfree(doms); | |
7131 | } | |
7132 | ||
1a20ff27 | 7133 | /* |
41a2d6cf | 7134 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7135 | * For now this just excludes isolated cpus, but could be used to |
7136 | * exclude other special cases in the future. | |
1a20ff27 | 7137 | */ |
96f874e2 | 7138 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7139 | { |
7378547f MM |
7140 | int err; |
7141 | ||
22e52b07 | 7142 | arch_update_cpu_topology(); |
029190c5 | 7143 | ndoms_cur = 1; |
acc3f5d7 | 7144 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7145 | if (!doms_cur) |
acc3f5d7 RR |
7146 | doms_cur = &fallback_doms; |
7147 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7148 | dattr_cur = NULL; |
acc3f5d7 | 7149 | err = build_sched_domains(doms_cur[0]); |
6382bc90 | 7150 | register_sched_domain_sysctl(); |
7378547f MM |
7151 | |
7152 | return err; | |
1a20ff27 DG |
7153 | } |
7154 | ||
96f874e2 RR |
7155 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
7156 | struct cpumask *tmpmask) | |
1da177e4 | 7157 | { |
7c16ec58 | 7158 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7159 | } |
1da177e4 | 7160 | |
1a20ff27 DG |
7161 | /* |
7162 | * Detach sched domains from a group of cpus specified in cpu_map | |
7163 | * These cpus will now be attached to the NULL domain | |
7164 | */ | |
96f874e2 | 7165 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7166 | { |
96f874e2 RR |
7167 | /* Save because hotplug lock held. */ |
7168 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
7169 | int i; |
7170 | ||
abcd083a | 7171 | for_each_cpu(i, cpu_map) |
57d885fe | 7172 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 7173 | synchronize_sched(); |
96f874e2 | 7174 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
7175 | } |
7176 | ||
1d3504fc HS |
7177 | /* handle null as "default" */ |
7178 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7179 | struct sched_domain_attr *new, int idx_new) | |
7180 | { | |
7181 | struct sched_domain_attr tmp; | |
7182 | ||
7183 | /* fast path */ | |
7184 | if (!new && !cur) | |
7185 | return 1; | |
7186 | ||
7187 | tmp = SD_ATTR_INIT; | |
7188 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7189 | new ? (new + idx_new) : &tmp, | |
7190 | sizeof(struct sched_domain_attr)); | |
7191 | } | |
7192 | ||
029190c5 PJ |
7193 | /* |
7194 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7195 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7196 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7197 | * It destroys each deleted domain and builds each new domain. | |
7198 | * | |
acc3f5d7 | 7199 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7200 | * The masks don't intersect (don't overlap.) We should setup one |
7201 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7202 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7203 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7204 | * it as it is. | |
7205 | * | |
acc3f5d7 RR |
7206 | * The passed in 'doms_new' should be allocated using |
7207 | * alloc_sched_domains. This routine takes ownership of it and will | |
7208 | * free_sched_domains it when done with it. If the caller failed the | |
7209 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7210 | * and partition_sched_domains() will fallback to the single partition | |
7211 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7212 | * |
96f874e2 | 7213 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7214 | * ndoms_new == 0 is a special case for destroying existing domains, |
7215 | * and it will not create the default domain. | |
dfb512ec | 7216 | * |
029190c5 PJ |
7217 | * Call with hotplug lock held |
7218 | */ | |
acc3f5d7 | 7219 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7220 | struct sched_domain_attr *dattr_new) |
029190c5 | 7221 | { |
dfb512ec | 7222 | int i, j, n; |
d65bd5ec | 7223 | int new_topology; |
029190c5 | 7224 | |
712555ee | 7225 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7226 | |
7378547f MM |
7227 | /* always unregister in case we don't destroy any domains */ |
7228 | unregister_sched_domain_sysctl(); | |
7229 | ||
d65bd5ec HC |
7230 | /* Let architecture update cpu core mappings. */ |
7231 | new_topology = arch_update_cpu_topology(); | |
7232 | ||
dfb512ec | 7233 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7234 | |
7235 | /* Destroy deleted domains */ | |
7236 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7237 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7238 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7239 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7240 | goto match1; |
7241 | } | |
7242 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7243 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7244 | match1: |
7245 | ; | |
7246 | } | |
7247 | ||
e761b772 MK |
7248 | if (doms_new == NULL) { |
7249 | ndoms_cur = 0; | |
acc3f5d7 | 7250 | doms_new = &fallback_doms; |
6ad4c188 | 7251 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7252 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7253 | } |
7254 | ||
029190c5 PJ |
7255 | /* Build new domains */ |
7256 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7257 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7258 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7259 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7260 | goto match2; |
7261 | } | |
7262 | /* no match - add a new doms_new */ | |
acc3f5d7 | 7263 | __build_sched_domains(doms_new[i], |
1d3504fc | 7264 | dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7265 | match2: |
7266 | ; | |
7267 | } | |
7268 | ||
7269 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7270 | if (doms_cur != &fallback_doms) |
7271 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7272 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7273 | doms_cur = doms_new; |
1d3504fc | 7274 | dattr_cur = dattr_new; |
029190c5 | 7275 | ndoms_cur = ndoms_new; |
7378547f MM |
7276 | |
7277 | register_sched_domain_sysctl(); | |
a1835615 | 7278 | |
712555ee | 7279 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7280 | } |
7281 | ||
5c45bf27 | 7282 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 7283 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 7284 | { |
95402b38 | 7285 | get_online_cpus(); |
dfb512ec MK |
7286 | |
7287 | /* Destroy domains first to force the rebuild */ | |
7288 | partition_sched_domains(0, NULL, NULL); | |
7289 | ||
e761b772 | 7290 | rebuild_sched_domains(); |
95402b38 | 7291 | put_online_cpus(); |
5c45bf27 SS |
7292 | } |
7293 | ||
7294 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7295 | { | |
afb8a9b7 | 7296 | unsigned int level = 0; |
5c45bf27 | 7297 | |
afb8a9b7 GS |
7298 | if (sscanf(buf, "%u", &level) != 1) |
7299 | return -EINVAL; | |
7300 | ||
7301 | /* | |
7302 | * level is always be positive so don't check for | |
7303 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7304 | * What happens on 0 or 1 byte write, | |
7305 | * need to check for count as well? | |
7306 | */ | |
7307 | ||
7308 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7309 | return -EINVAL; |
7310 | ||
7311 | if (smt) | |
afb8a9b7 | 7312 | sched_smt_power_savings = level; |
5c45bf27 | 7313 | else |
afb8a9b7 | 7314 | sched_mc_power_savings = level; |
5c45bf27 | 7315 | |
c70f22d2 | 7316 | arch_reinit_sched_domains(); |
5c45bf27 | 7317 | |
c70f22d2 | 7318 | return count; |
5c45bf27 SS |
7319 | } |
7320 | ||
5c45bf27 | 7321 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7322 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7323 | struct sysdev_class_attribute *attr, |
f718cd4a | 7324 | char *page) |
5c45bf27 SS |
7325 | { |
7326 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7327 | } | |
f718cd4a | 7328 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7329 | struct sysdev_class_attribute *attr, |
48f24c4d | 7330 | const char *buf, size_t count) |
5c45bf27 SS |
7331 | { |
7332 | return sched_power_savings_store(buf, count, 0); | |
7333 | } | |
f718cd4a AK |
7334 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7335 | sched_mc_power_savings_show, | |
7336 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7337 | #endif |
7338 | ||
7339 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7340 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7341 | struct sysdev_class_attribute *attr, |
f718cd4a | 7342 | char *page) |
5c45bf27 SS |
7343 | { |
7344 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7345 | } | |
f718cd4a | 7346 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7347 | struct sysdev_class_attribute *attr, |
48f24c4d | 7348 | const char *buf, size_t count) |
5c45bf27 SS |
7349 | { |
7350 | return sched_power_savings_store(buf, count, 1); | |
7351 | } | |
f718cd4a AK |
7352 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7353 | sched_smt_power_savings_show, | |
6707de00 AB |
7354 | sched_smt_power_savings_store); |
7355 | #endif | |
7356 | ||
39aac648 | 7357 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7358 | { |
7359 | int err = 0; | |
7360 | ||
7361 | #ifdef CONFIG_SCHED_SMT | |
7362 | if (smt_capable()) | |
7363 | err = sysfs_create_file(&cls->kset.kobj, | |
7364 | &attr_sched_smt_power_savings.attr); | |
7365 | #endif | |
7366 | #ifdef CONFIG_SCHED_MC | |
7367 | if (!err && mc_capable()) | |
7368 | err = sysfs_create_file(&cls->kset.kobj, | |
7369 | &attr_sched_mc_power_savings.attr); | |
7370 | #endif | |
7371 | return err; | |
7372 | } | |
6d6bc0ad | 7373 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7374 | |
e761b772 | 7375 | #ifndef CONFIG_CPUSETS |
1da177e4 | 7376 | /* |
e761b772 MK |
7377 | * Add online and remove offline CPUs from the scheduler domains. |
7378 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
7379 | */ |
7380 | static int update_sched_domains(struct notifier_block *nfb, | |
7381 | unsigned long action, void *hcpu) | |
e761b772 MK |
7382 | { |
7383 | switch (action) { | |
7384 | case CPU_ONLINE: | |
7385 | case CPU_ONLINE_FROZEN: | |
6ad4c188 PZ |
7386 | case CPU_DOWN_PREPARE: |
7387 | case CPU_DOWN_PREPARE_FROZEN: | |
7388 | case CPU_DOWN_FAILED: | |
7389 | case CPU_DOWN_FAILED_FROZEN: | |
dfb512ec | 7390 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
7391 | return NOTIFY_OK; |
7392 | ||
7393 | default: | |
7394 | return NOTIFY_DONE; | |
7395 | } | |
7396 | } | |
7397 | #endif | |
7398 | ||
7399 | static int update_runtime(struct notifier_block *nfb, | |
7400 | unsigned long action, void *hcpu) | |
1da177e4 | 7401 | { |
7def2be1 PZ |
7402 | int cpu = (int)(long)hcpu; |
7403 | ||
1da177e4 | 7404 | switch (action) { |
1da177e4 | 7405 | case CPU_DOWN_PREPARE: |
8bb78442 | 7406 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 7407 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
7408 | return NOTIFY_OK; |
7409 | ||
1da177e4 | 7410 | case CPU_DOWN_FAILED: |
8bb78442 | 7411 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 7412 | case CPU_ONLINE: |
8bb78442 | 7413 | case CPU_ONLINE_FROZEN: |
7def2be1 | 7414 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
7415 | return NOTIFY_OK; |
7416 | ||
1da177e4 LT |
7417 | default: |
7418 | return NOTIFY_DONE; | |
7419 | } | |
1da177e4 | 7420 | } |
1da177e4 LT |
7421 | |
7422 | void __init sched_init_smp(void) | |
7423 | { | |
dcc30a35 RR |
7424 | cpumask_var_t non_isolated_cpus; |
7425 | ||
7426 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 7427 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 7428 | |
434d53b0 MT |
7429 | #if defined(CONFIG_NUMA) |
7430 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
7431 | GFP_KERNEL); | |
7432 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
7433 | #endif | |
95402b38 | 7434 | get_online_cpus(); |
712555ee | 7435 | mutex_lock(&sched_domains_mutex); |
6ad4c188 | 7436 | arch_init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
7437 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
7438 | if (cpumask_empty(non_isolated_cpus)) | |
7439 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7440 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 7441 | put_online_cpus(); |
e761b772 MK |
7442 | |
7443 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
7444 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
7445 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
7446 | #endif |
7447 | ||
7448 | /* RT runtime code needs to handle some hotplug events */ | |
7449 | hotcpu_notifier(update_runtime, 0); | |
7450 | ||
b328ca18 | 7451 | init_hrtick(); |
5c1e1767 NP |
7452 | |
7453 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 7454 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 7455 | BUG(); |
19978ca6 | 7456 | sched_init_granularity(); |
dcc30a35 | 7457 | free_cpumask_var(non_isolated_cpus); |
4212823f | 7458 | |
0e3900e6 | 7459 | init_sched_rt_class(); |
1da177e4 LT |
7460 | } |
7461 | #else | |
7462 | void __init sched_init_smp(void) | |
7463 | { | |
19978ca6 | 7464 | sched_init_granularity(); |
1da177e4 LT |
7465 | } |
7466 | #endif /* CONFIG_SMP */ | |
7467 | ||
cd1bb94b AB |
7468 | const_debug unsigned int sysctl_timer_migration = 1; |
7469 | ||
1da177e4 LT |
7470 | int in_sched_functions(unsigned long addr) |
7471 | { | |
1da177e4 LT |
7472 | return in_lock_functions(addr) || |
7473 | (addr >= (unsigned long)__sched_text_start | |
7474 | && addr < (unsigned long)__sched_text_end); | |
7475 | } | |
7476 | ||
a9957449 | 7477 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
7478 | { |
7479 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 7480 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
7481 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7482 | cfs_rq->rq = rq; | |
7483 | #endif | |
67e9fb2a | 7484 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
7485 | } |
7486 | ||
fa85ae24 PZ |
7487 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
7488 | { | |
7489 | struct rt_prio_array *array; | |
7490 | int i; | |
7491 | ||
7492 | array = &rt_rq->active; | |
7493 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
7494 | INIT_LIST_HEAD(array->queue + i); | |
7495 | __clear_bit(i, array->bitmap); | |
7496 | } | |
7497 | /* delimiter for bitsearch: */ | |
7498 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
7499 | ||
052f1dc7 | 7500 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 7501 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 7502 | #ifdef CONFIG_SMP |
e864c499 | 7503 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 7504 | #endif |
48d5e258 | 7505 | #endif |
fa85ae24 PZ |
7506 | #ifdef CONFIG_SMP |
7507 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 7508 | rt_rq->overloaded = 0; |
05fa785c | 7509 | plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
7510 | #endif |
7511 | ||
7512 | rt_rq->rt_time = 0; | |
7513 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 7514 | rt_rq->rt_runtime = 0; |
0986b11b | 7515 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
6f505b16 | 7516 | |
052f1dc7 | 7517 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 7518 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
7519 | rt_rq->rq = rq; |
7520 | #endif | |
fa85ae24 PZ |
7521 | } |
7522 | ||
6f505b16 | 7523 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
7524 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
7525 | struct sched_entity *se, int cpu, int add, | |
7526 | struct sched_entity *parent) | |
6f505b16 | 7527 | { |
ec7dc8ac | 7528 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
7529 | tg->cfs_rq[cpu] = cfs_rq; |
7530 | init_cfs_rq(cfs_rq, rq); | |
7531 | cfs_rq->tg = tg; | |
7532 | if (add) | |
7533 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
7534 | ||
7535 | tg->se[cpu] = se; | |
354d60c2 DG |
7536 | /* se could be NULL for init_task_group */ |
7537 | if (!se) | |
7538 | return; | |
7539 | ||
ec7dc8ac DG |
7540 | if (!parent) |
7541 | se->cfs_rq = &rq->cfs; | |
7542 | else | |
7543 | se->cfs_rq = parent->my_q; | |
7544 | ||
6f505b16 PZ |
7545 | se->my_q = cfs_rq; |
7546 | se->load.weight = tg->shares; | |
e05510d0 | 7547 | se->load.inv_weight = 0; |
ec7dc8ac | 7548 | se->parent = parent; |
6f505b16 | 7549 | } |
052f1dc7 | 7550 | #endif |
6f505b16 | 7551 | |
052f1dc7 | 7552 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
7553 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
7554 | struct sched_rt_entity *rt_se, int cpu, int add, | |
7555 | struct sched_rt_entity *parent) | |
6f505b16 | 7556 | { |
ec7dc8ac DG |
7557 | struct rq *rq = cpu_rq(cpu); |
7558 | ||
6f505b16 PZ |
7559 | tg->rt_rq[cpu] = rt_rq; |
7560 | init_rt_rq(rt_rq, rq); | |
7561 | rt_rq->tg = tg; | |
ac086bc2 | 7562 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
7563 | if (add) |
7564 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
7565 | ||
7566 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
7567 | if (!rt_se) |
7568 | return; | |
7569 | ||
ec7dc8ac DG |
7570 | if (!parent) |
7571 | rt_se->rt_rq = &rq->rt; | |
7572 | else | |
7573 | rt_se->rt_rq = parent->my_q; | |
7574 | ||
6f505b16 | 7575 | rt_se->my_q = rt_rq; |
ec7dc8ac | 7576 | rt_se->parent = parent; |
6f505b16 PZ |
7577 | INIT_LIST_HEAD(&rt_se->run_list); |
7578 | } | |
7579 | #endif | |
7580 | ||
1da177e4 LT |
7581 | void __init sched_init(void) |
7582 | { | |
dd41f596 | 7583 | int i, j; |
434d53b0 MT |
7584 | unsigned long alloc_size = 0, ptr; |
7585 | ||
7586 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7587 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
7588 | #endif | |
7589 | #ifdef CONFIG_RT_GROUP_SCHED | |
7590 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7591 | #endif |
df7c8e84 | 7592 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 7593 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 7594 | #endif |
434d53b0 | 7595 | if (alloc_size) { |
36b7b6d4 | 7596 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
7597 | |
7598 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7599 | init_task_group.se = (struct sched_entity **)ptr; | |
7600 | ptr += nr_cpu_ids * sizeof(void **); | |
7601 | ||
7602 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
7603 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7604 | |
6d6bc0ad | 7605 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 MT |
7606 | #ifdef CONFIG_RT_GROUP_SCHED |
7607 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
7608 | ptr += nr_cpu_ids * sizeof(void **); | |
7609 | ||
7610 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
7611 | ptr += nr_cpu_ids * sizeof(void **); |
7612 | ||
6d6bc0ad | 7613 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
7614 | #ifdef CONFIG_CPUMASK_OFFSTACK |
7615 | for_each_possible_cpu(i) { | |
7616 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
7617 | ptr += cpumask_size(); | |
7618 | } | |
7619 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 7620 | } |
dd41f596 | 7621 | |
57d885fe GH |
7622 | #ifdef CONFIG_SMP |
7623 | init_defrootdomain(); | |
7624 | #endif | |
7625 | ||
d0b27fa7 PZ |
7626 | init_rt_bandwidth(&def_rt_bandwidth, |
7627 | global_rt_period(), global_rt_runtime()); | |
7628 | ||
7629 | #ifdef CONFIG_RT_GROUP_SCHED | |
7630 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
7631 | global_rt_period(), global_rt_runtime()); | |
6d6bc0ad | 7632 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7633 | |
7c941438 | 7634 | #ifdef CONFIG_CGROUP_SCHED |
6f505b16 | 7635 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
7636 | INIT_LIST_HEAD(&init_task_group.children); |
7637 | ||
7c941438 | 7638 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 7639 | |
4a6cc4bd JK |
7640 | #if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP |
7641 | update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), | |
7642 | __alignof__(unsigned long)); | |
7643 | #endif | |
0a945022 | 7644 | for_each_possible_cpu(i) { |
70b97a7f | 7645 | struct rq *rq; |
1da177e4 LT |
7646 | |
7647 | rq = cpu_rq(i); | |
05fa785c | 7648 | raw_spin_lock_init(&rq->lock); |
7897986b | 7649 | rq->nr_running = 0; |
dce48a84 TG |
7650 | rq->calc_load_active = 0; |
7651 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 7652 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 7653 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 7654 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 7655 | init_task_group.shares = init_task_group_load; |
6f505b16 | 7656 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
7657 | #ifdef CONFIG_CGROUP_SCHED |
7658 | /* | |
7659 | * How much cpu bandwidth does init_task_group get? | |
7660 | * | |
7661 | * In case of task-groups formed thr' the cgroup filesystem, it | |
7662 | * gets 100% of the cpu resources in the system. This overall | |
7663 | * system cpu resource is divided among the tasks of | |
7664 | * init_task_group and its child task-groups in a fair manner, | |
7665 | * based on each entity's (task or task-group's) weight | |
7666 | * (se->load.weight). | |
7667 | * | |
7668 | * In other words, if init_task_group has 10 tasks of weight | |
7669 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
7670 | * then A0's share of the cpu resource is: | |
7671 | * | |
0d905bca | 7672 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
7673 | * |
7674 | * We achieve this by letting init_task_group's tasks sit | |
7675 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
7676 | */ | |
ec7dc8ac | 7677 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
052f1dc7 | 7678 | #endif |
354d60c2 DG |
7679 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
7680 | ||
7681 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 7682 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 7683 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 7684 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 7685 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 7686 | #endif |
dd41f596 | 7687 | #endif |
1da177e4 | 7688 | |
dd41f596 IM |
7689 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
7690 | rq->cpu_load[j] = 0; | |
1da177e4 | 7691 | #ifdef CONFIG_SMP |
41c7ce9a | 7692 | rq->sd = NULL; |
57d885fe | 7693 | rq->rd = NULL; |
3f029d3c | 7694 | rq->post_schedule = 0; |
1da177e4 | 7695 | rq->active_balance = 0; |
dd41f596 | 7696 | rq->next_balance = jiffies; |
1da177e4 | 7697 | rq->push_cpu = 0; |
0a2966b4 | 7698 | rq->cpu = i; |
1f11eb6a | 7699 | rq->online = 0; |
1da177e4 | 7700 | rq->migration_thread = NULL; |
eae0c9df MG |
7701 | rq->idle_stamp = 0; |
7702 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
1da177e4 | 7703 | INIT_LIST_HEAD(&rq->migration_queue); |
dc938520 | 7704 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 7705 | #endif |
8f4d37ec | 7706 | init_rq_hrtick(rq); |
1da177e4 | 7707 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
7708 | } |
7709 | ||
2dd73a4f | 7710 | set_load_weight(&init_task); |
b50f60ce | 7711 | |
e107be36 AK |
7712 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7713 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7714 | #endif | |
7715 | ||
c9819f45 | 7716 | #ifdef CONFIG_SMP |
962cf36c | 7717 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
7718 | #endif |
7719 | ||
b50f60ce | 7720 | #ifdef CONFIG_RT_MUTEXES |
1d615482 | 7721 | plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); |
b50f60ce HC |
7722 | #endif |
7723 | ||
1da177e4 LT |
7724 | /* |
7725 | * The boot idle thread does lazy MMU switching as well: | |
7726 | */ | |
7727 | atomic_inc(&init_mm.mm_count); | |
7728 | enter_lazy_tlb(&init_mm, current); | |
7729 | ||
7730 | /* | |
7731 | * Make us the idle thread. Technically, schedule() should not be | |
7732 | * called from this thread, however somewhere below it might be, | |
7733 | * but because we are the idle thread, we just pick up running again | |
7734 | * when this runqueue becomes "idle". | |
7735 | */ | |
7736 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7737 | |
7738 | calc_load_update = jiffies + LOAD_FREQ; | |
7739 | ||
dd41f596 IM |
7740 | /* |
7741 | * During early bootup we pretend to be a normal task: | |
7742 | */ | |
7743 | current->sched_class = &fair_sched_class; | |
6892b75e | 7744 | |
6a7b3dc3 | 7745 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 7746 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 7747 | #ifdef CONFIG_SMP |
7d1e6a9b | 7748 | #ifdef CONFIG_NO_HZ |
49557e62 | 7749 | zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); |
4bdddf8f | 7750 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); |
7d1e6a9b | 7751 | #endif |
bdddd296 RR |
7752 | /* May be allocated at isolcpus cmdline parse time */ |
7753 | if (cpu_isolated_map == NULL) | |
7754 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 7755 | #endif /* SMP */ |
6a7b3dc3 | 7756 | |
cdd6c482 | 7757 | perf_event_init(); |
0d905bca | 7758 | |
6892b75e | 7759 | scheduler_running = 1; |
1da177e4 LT |
7760 | } |
7761 | ||
7762 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
7763 | static inline int preempt_count_equals(int preempt_offset) |
7764 | { | |
234da7bc | 7765 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 FW |
7766 | |
7767 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
7768 | } | |
7769 | ||
d894837f | 7770 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7771 | { |
48f24c4d | 7772 | #ifdef in_atomic |
1da177e4 LT |
7773 | static unsigned long prev_jiffy; /* ratelimiting */ |
7774 | ||
e4aafea2 FW |
7775 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
7776 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
7777 | return; |
7778 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7779 | return; | |
7780 | prev_jiffy = jiffies; | |
7781 | ||
3df0fc5b PZ |
7782 | printk(KERN_ERR |
7783 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7784 | file, line); | |
7785 | printk(KERN_ERR | |
7786 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7787 | in_atomic(), irqs_disabled(), | |
7788 | current->pid, current->comm); | |
aef745fc IM |
7789 | |
7790 | debug_show_held_locks(current); | |
7791 | if (irqs_disabled()) | |
7792 | print_irqtrace_events(current); | |
7793 | dump_stack(); | |
1da177e4 LT |
7794 | #endif |
7795 | } | |
7796 | EXPORT_SYMBOL(__might_sleep); | |
7797 | #endif | |
7798 | ||
7799 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7800 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7801 | { | |
7802 | int on_rq; | |
3e51f33f | 7803 | |
3a5e4dc1 AK |
7804 | on_rq = p->se.on_rq; |
7805 | if (on_rq) | |
7806 | deactivate_task(rq, p, 0); | |
7807 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
7808 | if (on_rq) { | |
7809 | activate_task(rq, p, 0); | |
7810 | resched_task(rq->curr); | |
7811 | } | |
7812 | } | |
7813 | ||
1da177e4 LT |
7814 | void normalize_rt_tasks(void) |
7815 | { | |
a0f98a1c | 7816 | struct task_struct *g, *p; |
1da177e4 | 7817 | unsigned long flags; |
70b97a7f | 7818 | struct rq *rq; |
1da177e4 | 7819 | |
4cf5d77a | 7820 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 7821 | do_each_thread(g, p) { |
178be793 IM |
7822 | /* |
7823 | * Only normalize user tasks: | |
7824 | */ | |
7825 | if (!p->mm) | |
7826 | continue; | |
7827 | ||
6cfb0d5d | 7828 | p->se.exec_start = 0; |
6cfb0d5d | 7829 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7830 | p->se.statistics.wait_start = 0; |
7831 | p->se.statistics.sleep_start = 0; | |
7832 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7833 | #endif |
dd41f596 IM |
7834 | |
7835 | if (!rt_task(p)) { | |
7836 | /* | |
7837 | * Renice negative nice level userspace | |
7838 | * tasks back to 0: | |
7839 | */ | |
7840 | if (TASK_NICE(p) < 0 && p->mm) | |
7841 | set_user_nice(p, 0); | |
1da177e4 | 7842 | continue; |
dd41f596 | 7843 | } |
1da177e4 | 7844 | |
1d615482 | 7845 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7846 | rq = __task_rq_lock(p); |
1da177e4 | 7847 | |
178be793 | 7848 | normalize_task(rq, p); |
3a5e4dc1 | 7849 | |
b29739f9 | 7850 | __task_rq_unlock(rq); |
1d615482 | 7851 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7852 | } while_each_thread(g, p); |
7853 | ||
4cf5d77a | 7854 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7855 | } |
7856 | ||
7857 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
7858 | |
7859 | #ifdef CONFIG_IA64 | |
7860 | /* | |
7861 | * These functions are only useful for the IA64 MCA handling. | |
7862 | * | |
7863 | * They can only be called when the whole system has been | |
7864 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7865 | * activity can take place. Using them for anything else would | |
7866 | * be a serious bug, and as a result, they aren't even visible | |
7867 | * under any other configuration. | |
7868 | */ | |
7869 | ||
7870 | /** | |
7871 | * curr_task - return the current task for a given cpu. | |
7872 | * @cpu: the processor in question. | |
7873 | * | |
7874 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7875 | */ | |
36c8b586 | 7876 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7877 | { |
7878 | return cpu_curr(cpu); | |
7879 | } | |
7880 | ||
7881 | /** | |
7882 | * set_curr_task - set the current task for a given cpu. | |
7883 | * @cpu: the processor in question. | |
7884 | * @p: the task pointer to set. | |
7885 | * | |
7886 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7887 | * are serviced on a separate stack. It allows the architecture to switch the |
7888 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7889 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7890 | * and caller must save the original value of the current task (see | |
7891 | * curr_task() above) and restore that value before reenabling interrupts and | |
7892 | * re-starting the system. | |
7893 | * | |
7894 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7895 | */ | |
36c8b586 | 7896 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7897 | { |
7898 | cpu_curr(cpu) = p; | |
7899 | } | |
7900 | ||
7901 | #endif | |
29f59db3 | 7902 | |
bccbe08a PZ |
7903 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7904 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
7905 | { |
7906 | int i; | |
7907 | ||
7908 | for_each_possible_cpu(i) { | |
7909 | if (tg->cfs_rq) | |
7910 | kfree(tg->cfs_rq[i]); | |
7911 | if (tg->se) | |
7912 | kfree(tg->se[i]); | |
6f505b16 PZ |
7913 | } |
7914 | ||
7915 | kfree(tg->cfs_rq); | |
7916 | kfree(tg->se); | |
6f505b16 PZ |
7917 | } |
7918 | ||
ec7dc8ac DG |
7919 | static |
7920 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 7921 | { |
29f59db3 | 7922 | struct cfs_rq *cfs_rq; |
eab17229 | 7923 | struct sched_entity *se; |
9b5b7751 | 7924 | struct rq *rq; |
29f59db3 SV |
7925 | int i; |
7926 | ||
434d53b0 | 7927 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
7928 | if (!tg->cfs_rq) |
7929 | goto err; | |
434d53b0 | 7930 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
7931 | if (!tg->se) |
7932 | goto err; | |
052f1dc7 PZ |
7933 | |
7934 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
7935 | |
7936 | for_each_possible_cpu(i) { | |
9b5b7751 | 7937 | rq = cpu_rq(i); |
29f59db3 | 7938 | |
eab17229 LZ |
7939 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
7940 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
7941 | if (!cfs_rq) |
7942 | goto err; | |
7943 | ||
eab17229 LZ |
7944 | se = kzalloc_node(sizeof(struct sched_entity), |
7945 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 7946 | if (!se) |
dfc12eb2 | 7947 | goto err_free_rq; |
29f59db3 | 7948 | |
eab17229 | 7949 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
7950 | } |
7951 | ||
7952 | return 1; | |
7953 | ||
dfc12eb2 PC |
7954 | err_free_rq: |
7955 | kfree(cfs_rq); | |
bccbe08a PZ |
7956 | err: |
7957 | return 0; | |
7958 | } | |
7959 | ||
7960 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
7961 | { | |
7962 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
7963 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
7964 | } | |
7965 | ||
7966 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
7967 | { | |
7968 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
7969 | } | |
6d6bc0ad | 7970 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
7971 | static inline void free_fair_sched_group(struct task_group *tg) |
7972 | { | |
7973 | } | |
7974 | ||
ec7dc8ac DG |
7975 | static inline |
7976 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
7977 | { |
7978 | return 1; | |
7979 | } | |
7980 | ||
7981 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
7982 | { | |
7983 | } | |
7984 | ||
7985 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
7986 | { | |
7987 | } | |
6d6bc0ad | 7988 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
7989 | |
7990 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
7991 | static void free_rt_sched_group(struct task_group *tg) |
7992 | { | |
7993 | int i; | |
7994 | ||
d0b27fa7 PZ |
7995 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
7996 | ||
bccbe08a PZ |
7997 | for_each_possible_cpu(i) { |
7998 | if (tg->rt_rq) | |
7999 | kfree(tg->rt_rq[i]); | |
8000 | if (tg->rt_se) | |
8001 | kfree(tg->rt_se[i]); | |
8002 | } | |
8003 | ||
8004 | kfree(tg->rt_rq); | |
8005 | kfree(tg->rt_se); | |
8006 | } | |
8007 | ||
ec7dc8ac DG |
8008 | static |
8009 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8010 | { |
8011 | struct rt_rq *rt_rq; | |
eab17229 | 8012 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8013 | struct rq *rq; |
8014 | int i; | |
8015 | ||
434d53b0 | 8016 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8017 | if (!tg->rt_rq) |
8018 | goto err; | |
434d53b0 | 8019 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8020 | if (!tg->rt_se) |
8021 | goto err; | |
8022 | ||
d0b27fa7 PZ |
8023 | init_rt_bandwidth(&tg->rt_bandwidth, |
8024 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8025 | |
8026 | for_each_possible_cpu(i) { | |
8027 | rq = cpu_rq(i); | |
8028 | ||
eab17229 LZ |
8029 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8030 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8031 | if (!rt_rq) |
8032 | goto err; | |
29f59db3 | 8033 | |
eab17229 LZ |
8034 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8035 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 8036 | if (!rt_se) |
dfc12eb2 | 8037 | goto err_free_rq; |
29f59db3 | 8038 | |
eab17229 | 8039 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
8040 | } |
8041 | ||
bccbe08a PZ |
8042 | return 1; |
8043 | ||
dfc12eb2 PC |
8044 | err_free_rq: |
8045 | kfree(rt_rq); | |
bccbe08a PZ |
8046 | err: |
8047 | return 0; | |
8048 | } | |
8049 | ||
8050 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8051 | { | |
8052 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
8053 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
8054 | } | |
8055 | ||
8056 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8057 | { | |
8058 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
8059 | } | |
6d6bc0ad | 8060 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8061 | static inline void free_rt_sched_group(struct task_group *tg) |
8062 | { | |
8063 | } | |
8064 | ||
ec7dc8ac DG |
8065 | static inline |
8066 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8067 | { |
8068 | return 1; | |
8069 | } | |
8070 | ||
8071 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8072 | { | |
8073 | } | |
8074 | ||
8075 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8076 | { | |
8077 | } | |
6d6bc0ad | 8078 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8079 | |
7c941438 | 8080 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
8081 | static void free_sched_group(struct task_group *tg) |
8082 | { | |
8083 | free_fair_sched_group(tg); | |
8084 | free_rt_sched_group(tg); | |
8085 | kfree(tg); | |
8086 | } | |
8087 | ||
8088 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8089 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8090 | { |
8091 | struct task_group *tg; | |
8092 | unsigned long flags; | |
8093 | int i; | |
8094 | ||
8095 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8096 | if (!tg) | |
8097 | return ERR_PTR(-ENOMEM); | |
8098 | ||
ec7dc8ac | 8099 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8100 | goto err; |
8101 | ||
ec7dc8ac | 8102 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8103 | goto err; |
8104 | ||
8ed36996 | 8105 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8106 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8107 | register_fair_sched_group(tg, i); |
8108 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8109 | } |
6f505b16 | 8110 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8111 | |
8112 | WARN_ON(!parent); /* root should already exist */ | |
8113 | ||
8114 | tg->parent = parent; | |
f473aa5e | 8115 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8116 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8117 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8118 | |
9b5b7751 | 8119 | return tg; |
29f59db3 SV |
8120 | |
8121 | err: | |
6f505b16 | 8122 | free_sched_group(tg); |
29f59db3 SV |
8123 | return ERR_PTR(-ENOMEM); |
8124 | } | |
8125 | ||
9b5b7751 | 8126 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8127 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8128 | { |
29f59db3 | 8129 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8130 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8131 | } |
8132 | ||
9b5b7751 | 8133 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8134 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8135 | { |
8ed36996 | 8136 | unsigned long flags; |
9b5b7751 | 8137 | int i; |
29f59db3 | 8138 | |
8ed36996 | 8139 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8140 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8141 | unregister_fair_sched_group(tg, i); |
8142 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8143 | } |
6f505b16 | 8144 | list_del_rcu(&tg->list); |
f473aa5e | 8145 | list_del_rcu(&tg->siblings); |
8ed36996 | 8146 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8147 | |
9b5b7751 | 8148 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8149 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8150 | } |
8151 | ||
9b5b7751 | 8152 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8153 | * The caller of this function should have put the task in its new group |
8154 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8155 | * reflect its new group. | |
9b5b7751 SV |
8156 | */ |
8157 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8158 | { |
8159 | int on_rq, running; | |
8160 | unsigned long flags; | |
8161 | struct rq *rq; | |
8162 | ||
8163 | rq = task_rq_lock(tsk, &flags); | |
8164 | ||
051a1d1a | 8165 | running = task_current(rq, tsk); |
29f59db3 SV |
8166 | on_rq = tsk->se.on_rq; |
8167 | ||
0e1f3483 | 8168 | if (on_rq) |
29f59db3 | 8169 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8170 | if (unlikely(running)) |
8171 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8172 | |
6f505b16 | 8173 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 8174 | |
810b3817 PZ |
8175 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8176 | if (tsk->sched_class->moved_group) | |
88ec22d3 | 8177 | tsk->sched_class->moved_group(tsk, on_rq); |
810b3817 PZ |
8178 | #endif |
8179 | ||
0e1f3483 HS |
8180 | if (unlikely(running)) |
8181 | tsk->sched_class->set_curr_task(rq); | |
8182 | if (on_rq) | |
ea87bb78 | 8183 | enqueue_task(rq, tsk, 0, false); |
29f59db3 | 8184 | |
29f59db3 SV |
8185 | task_rq_unlock(rq, &flags); |
8186 | } | |
7c941438 | 8187 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8188 | |
052f1dc7 | 8189 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 8190 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
8191 | { |
8192 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
8193 | int on_rq; |
8194 | ||
29f59db3 | 8195 | on_rq = se->on_rq; |
62fb1851 | 8196 | if (on_rq) |
29f59db3 SV |
8197 | dequeue_entity(cfs_rq, se, 0); |
8198 | ||
8199 | se->load.weight = shares; | |
e05510d0 | 8200 | se->load.inv_weight = 0; |
29f59db3 | 8201 | |
62fb1851 | 8202 | if (on_rq) |
29f59db3 | 8203 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 8204 | } |
62fb1851 | 8205 | |
c09595f6 PZ |
8206 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
8207 | { | |
8208 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
8209 | struct rq *rq = cfs_rq->rq; | |
8210 | unsigned long flags; | |
8211 | ||
05fa785c | 8212 | raw_spin_lock_irqsave(&rq->lock, flags); |
c09595f6 | 8213 | __set_se_shares(se, shares); |
05fa785c | 8214 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
29f59db3 SV |
8215 | } |
8216 | ||
8ed36996 PZ |
8217 | static DEFINE_MUTEX(shares_mutex); |
8218 | ||
4cf86d77 | 8219 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8220 | { |
8221 | int i; | |
8ed36996 | 8222 | unsigned long flags; |
c61935fd | 8223 | |
ec7dc8ac DG |
8224 | /* |
8225 | * We can't change the weight of the root cgroup. | |
8226 | */ | |
8227 | if (!tg->se[0]) | |
8228 | return -EINVAL; | |
8229 | ||
18d95a28 PZ |
8230 | if (shares < MIN_SHARES) |
8231 | shares = MIN_SHARES; | |
cb4ad1ff MX |
8232 | else if (shares > MAX_SHARES) |
8233 | shares = MAX_SHARES; | |
62fb1851 | 8234 | |
8ed36996 | 8235 | mutex_lock(&shares_mutex); |
9b5b7751 | 8236 | if (tg->shares == shares) |
5cb350ba | 8237 | goto done; |
29f59db3 | 8238 | |
8ed36996 | 8239 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8240 | for_each_possible_cpu(i) |
8241 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 8242 | list_del_rcu(&tg->siblings); |
8ed36996 | 8243 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
8244 | |
8245 | /* wait for any ongoing reference to this group to finish */ | |
8246 | synchronize_sched(); | |
8247 | ||
8248 | /* | |
8249 | * Now we are free to modify the group's share on each cpu | |
8250 | * w/o tripping rebalance_share or load_balance_fair. | |
8251 | */ | |
9b5b7751 | 8252 | tg->shares = shares; |
c09595f6 PZ |
8253 | for_each_possible_cpu(i) { |
8254 | /* | |
8255 | * force a rebalance | |
8256 | */ | |
8257 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 8258 | set_se_shares(tg->se[i], shares); |
c09595f6 | 8259 | } |
29f59db3 | 8260 | |
6b2d7700 SV |
8261 | /* |
8262 | * Enable load balance activity on this group, by inserting it back on | |
8263 | * each cpu's rq->leaf_cfs_rq_list. | |
8264 | */ | |
8ed36996 | 8265 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8266 | for_each_possible_cpu(i) |
8267 | register_fair_sched_group(tg, i); | |
f473aa5e | 8268 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 8269 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 8270 | done: |
8ed36996 | 8271 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8272 | return 0; |
29f59db3 SV |
8273 | } |
8274 | ||
5cb350ba DG |
8275 | unsigned long sched_group_shares(struct task_group *tg) |
8276 | { | |
8277 | return tg->shares; | |
8278 | } | |
052f1dc7 | 8279 | #endif |
5cb350ba | 8280 | |
052f1dc7 | 8281 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8282 | /* |
9f0c1e56 | 8283 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 8284 | */ |
9f0c1e56 PZ |
8285 | static DEFINE_MUTEX(rt_constraints_mutex); |
8286 | ||
8287 | static unsigned long to_ratio(u64 period, u64 runtime) | |
8288 | { | |
8289 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8290 | return 1ULL << 20; |
9f0c1e56 | 8291 | |
9a7e0b18 | 8292 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
8293 | } |
8294 | ||
9a7e0b18 PZ |
8295 | /* Must be called with tasklist_lock held */ |
8296 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8297 | { |
9a7e0b18 | 8298 | struct task_struct *g, *p; |
b40b2e8e | 8299 | |
9a7e0b18 PZ |
8300 | do_each_thread(g, p) { |
8301 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8302 | return 1; | |
8303 | } while_each_thread(g, p); | |
b40b2e8e | 8304 | |
9a7e0b18 PZ |
8305 | return 0; |
8306 | } | |
b40b2e8e | 8307 | |
9a7e0b18 PZ |
8308 | struct rt_schedulable_data { |
8309 | struct task_group *tg; | |
8310 | u64 rt_period; | |
8311 | u64 rt_runtime; | |
8312 | }; | |
b40b2e8e | 8313 | |
9a7e0b18 PZ |
8314 | static int tg_schedulable(struct task_group *tg, void *data) |
8315 | { | |
8316 | struct rt_schedulable_data *d = data; | |
8317 | struct task_group *child; | |
8318 | unsigned long total, sum = 0; | |
8319 | u64 period, runtime; | |
b40b2e8e | 8320 | |
9a7e0b18 PZ |
8321 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8322 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8323 | |
9a7e0b18 PZ |
8324 | if (tg == d->tg) { |
8325 | period = d->rt_period; | |
8326 | runtime = d->rt_runtime; | |
b40b2e8e | 8327 | } |
b40b2e8e | 8328 | |
4653f803 PZ |
8329 | /* |
8330 | * Cannot have more runtime than the period. | |
8331 | */ | |
8332 | if (runtime > period && runtime != RUNTIME_INF) | |
8333 | return -EINVAL; | |
6f505b16 | 8334 | |
4653f803 PZ |
8335 | /* |
8336 | * Ensure we don't starve existing RT tasks. | |
8337 | */ | |
9a7e0b18 PZ |
8338 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8339 | return -EBUSY; | |
6f505b16 | 8340 | |
9a7e0b18 | 8341 | total = to_ratio(period, runtime); |
6f505b16 | 8342 | |
4653f803 PZ |
8343 | /* |
8344 | * Nobody can have more than the global setting allows. | |
8345 | */ | |
8346 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8347 | return -EINVAL; | |
6f505b16 | 8348 | |
4653f803 PZ |
8349 | /* |
8350 | * The sum of our children's runtime should not exceed our own. | |
8351 | */ | |
9a7e0b18 PZ |
8352 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8353 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8354 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8355 | |
9a7e0b18 PZ |
8356 | if (child == d->tg) { |
8357 | period = d->rt_period; | |
8358 | runtime = d->rt_runtime; | |
8359 | } | |
6f505b16 | 8360 | |
9a7e0b18 | 8361 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8362 | } |
6f505b16 | 8363 | |
9a7e0b18 PZ |
8364 | if (sum > total) |
8365 | return -EINVAL; | |
8366 | ||
8367 | return 0; | |
6f505b16 PZ |
8368 | } |
8369 | ||
9a7e0b18 | 8370 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8371 | { |
9a7e0b18 PZ |
8372 | struct rt_schedulable_data data = { |
8373 | .tg = tg, | |
8374 | .rt_period = period, | |
8375 | .rt_runtime = runtime, | |
8376 | }; | |
8377 | ||
8378 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
8379 | } |
8380 | ||
d0b27fa7 PZ |
8381 | static int tg_set_bandwidth(struct task_group *tg, |
8382 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 8383 | { |
ac086bc2 | 8384 | int i, err = 0; |
9f0c1e56 | 8385 | |
9f0c1e56 | 8386 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8387 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8388 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8389 | if (err) | |
9f0c1e56 | 8390 | goto unlock; |
ac086bc2 | 8391 | |
0986b11b | 8392 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8393 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8394 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8395 | |
8396 | for_each_possible_cpu(i) { | |
8397 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8398 | ||
0986b11b | 8399 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8400 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8401 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8402 | } |
0986b11b | 8403 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
9f0c1e56 | 8404 | unlock: |
521f1a24 | 8405 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8406 | mutex_unlock(&rt_constraints_mutex); |
8407 | ||
8408 | return err; | |
6f505b16 PZ |
8409 | } |
8410 | ||
d0b27fa7 PZ |
8411 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8412 | { | |
8413 | u64 rt_runtime, rt_period; | |
8414 | ||
8415 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8416 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8417 | if (rt_runtime_us < 0) | |
8418 | rt_runtime = RUNTIME_INF; | |
8419 | ||
8420 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
8421 | } | |
8422 | ||
9f0c1e56 PZ |
8423 | long sched_group_rt_runtime(struct task_group *tg) |
8424 | { | |
8425 | u64 rt_runtime_us; | |
8426 | ||
d0b27fa7 | 8427 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8428 | return -1; |
8429 | ||
d0b27fa7 | 8430 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8431 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8432 | return rt_runtime_us; | |
8433 | } | |
d0b27fa7 PZ |
8434 | |
8435 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8436 | { | |
8437 | u64 rt_runtime, rt_period; | |
8438 | ||
8439 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8440 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8441 | ||
619b0488 R |
8442 | if (rt_period == 0) |
8443 | return -EINVAL; | |
8444 | ||
d0b27fa7 PZ |
8445 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
8446 | } | |
8447 | ||
8448 | long sched_group_rt_period(struct task_group *tg) | |
8449 | { | |
8450 | u64 rt_period_us; | |
8451 | ||
8452 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8453 | do_div(rt_period_us, NSEC_PER_USEC); | |
8454 | return rt_period_us; | |
8455 | } | |
8456 | ||
8457 | static int sched_rt_global_constraints(void) | |
8458 | { | |
4653f803 | 8459 | u64 runtime, period; |
d0b27fa7 PZ |
8460 | int ret = 0; |
8461 | ||
ec5d4989 HS |
8462 | if (sysctl_sched_rt_period <= 0) |
8463 | return -EINVAL; | |
8464 | ||
4653f803 PZ |
8465 | runtime = global_rt_runtime(); |
8466 | period = global_rt_period(); | |
8467 | ||
8468 | /* | |
8469 | * Sanity check on the sysctl variables. | |
8470 | */ | |
8471 | if (runtime > period && runtime != RUNTIME_INF) | |
8472 | return -EINVAL; | |
10b612f4 | 8473 | |
d0b27fa7 | 8474 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 8475 | read_lock(&tasklist_lock); |
4653f803 | 8476 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 8477 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
8478 | mutex_unlock(&rt_constraints_mutex); |
8479 | ||
8480 | return ret; | |
8481 | } | |
54e99124 DG |
8482 | |
8483 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
8484 | { | |
8485 | /* Don't accept realtime tasks when there is no way for them to run */ | |
8486 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
8487 | return 0; | |
8488 | ||
8489 | return 1; | |
8490 | } | |
8491 | ||
6d6bc0ad | 8492 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8493 | static int sched_rt_global_constraints(void) |
8494 | { | |
ac086bc2 PZ |
8495 | unsigned long flags; |
8496 | int i; | |
8497 | ||
ec5d4989 HS |
8498 | if (sysctl_sched_rt_period <= 0) |
8499 | return -EINVAL; | |
8500 | ||
60aa605d PZ |
8501 | /* |
8502 | * There's always some RT tasks in the root group | |
8503 | * -- migration, kstopmachine etc.. | |
8504 | */ | |
8505 | if (sysctl_sched_rt_runtime == 0) | |
8506 | return -EBUSY; | |
8507 | ||
0986b11b | 8508 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
8509 | for_each_possible_cpu(i) { |
8510 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
8511 | ||
0986b11b | 8512 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8513 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 8514 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8515 | } |
0986b11b | 8516 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 8517 | |
d0b27fa7 PZ |
8518 | return 0; |
8519 | } | |
6d6bc0ad | 8520 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8521 | |
8522 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 8523 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
8524 | loff_t *ppos) |
8525 | { | |
8526 | int ret; | |
8527 | int old_period, old_runtime; | |
8528 | static DEFINE_MUTEX(mutex); | |
8529 | ||
8530 | mutex_lock(&mutex); | |
8531 | old_period = sysctl_sched_rt_period; | |
8532 | old_runtime = sysctl_sched_rt_runtime; | |
8533 | ||
8d65af78 | 8534 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
8535 | |
8536 | if (!ret && write) { | |
8537 | ret = sched_rt_global_constraints(); | |
8538 | if (ret) { | |
8539 | sysctl_sched_rt_period = old_period; | |
8540 | sysctl_sched_rt_runtime = old_runtime; | |
8541 | } else { | |
8542 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
8543 | def_rt_bandwidth.rt_period = | |
8544 | ns_to_ktime(global_rt_period()); | |
8545 | } | |
8546 | } | |
8547 | mutex_unlock(&mutex); | |
8548 | ||
8549 | return ret; | |
8550 | } | |
68318b8e | 8551 | |
052f1dc7 | 8552 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
8553 | |
8554 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 8555 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 8556 | { |
2b01dfe3 PM |
8557 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
8558 | struct task_group, css); | |
68318b8e SV |
8559 | } |
8560 | ||
8561 | static struct cgroup_subsys_state * | |
2b01dfe3 | 8562 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 8563 | { |
ec7dc8ac | 8564 | struct task_group *tg, *parent; |
68318b8e | 8565 | |
2b01dfe3 | 8566 | if (!cgrp->parent) { |
68318b8e | 8567 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
8568 | return &init_task_group.css; |
8569 | } | |
8570 | ||
ec7dc8ac DG |
8571 | parent = cgroup_tg(cgrp->parent); |
8572 | tg = sched_create_group(parent); | |
68318b8e SV |
8573 | if (IS_ERR(tg)) |
8574 | return ERR_PTR(-ENOMEM); | |
8575 | ||
68318b8e SV |
8576 | return &tg->css; |
8577 | } | |
8578 | ||
41a2d6cf IM |
8579 | static void |
8580 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 8581 | { |
2b01dfe3 | 8582 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8583 | |
8584 | sched_destroy_group(tg); | |
8585 | } | |
8586 | ||
41a2d6cf | 8587 | static int |
be367d09 | 8588 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 8589 | { |
b68aa230 | 8590 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 8591 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
8592 | return -EINVAL; |
8593 | #else | |
68318b8e SV |
8594 | /* We don't support RT-tasks being in separate groups */ |
8595 | if (tsk->sched_class != &fair_sched_class) | |
8596 | return -EINVAL; | |
b68aa230 | 8597 | #endif |
be367d09 BB |
8598 | return 0; |
8599 | } | |
68318b8e | 8600 | |
be367d09 BB |
8601 | static int |
8602 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
8603 | struct task_struct *tsk, bool threadgroup) | |
8604 | { | |
8605 | int retval = cpu_cgroup_can_attach_task(cgrp, tsk); | |
8606 | if (retval) | |
8607 | return retval; | |
8608 | if (threadgroup) { | |
8609 | struct task_struct *c; | |
8610 | rcu_read_lock(); | |
8611 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8612 | retval = cpu_cgroup_can_attach_task(cgrp, c); | |
8613 | if (retval) { | |
8614 | rcu_read_unlock(); | |
8615 | return retval; | |
8616 | } | |
8617 | } | |
8618 | rcu_read_unlock(); | |
8619 | } | |
68318b8e SV |
8620 | return 0; |
8621 | } | |
8622 | ||
8623 | static void | |
2b01dfe3 | 8624 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
be367d09 BB |
8625 | struct cgroup *old_cont, struct task_struct *tsk, |
8626 | bool threadgroup) | |
68318b8e SV |
8627 | { |
8628 | sched_move_task(tsk); | |
be367d09 BB |
8629 | if (threadgroup) { |
8630 | struct task_struct *c; | |
8631 | rcu_read_lock(); | |
8632 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8633 | sched_move_task(c); | |
8634 | } | |
8635 | rcu_read_unlock(); | |
8636 | } | |
68318b8e SV |
8637 | } |
8638 | ||
052f1dc7 | 8639 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 8640 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 8641 | u64 shareval) |
68318b8e | 8642 | { |
2b01dfe3 | 8643 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
8644 | } |
8645 | ||
f4c753b7 | 8646 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 8647 | { |
2b01dfe3 | 8648 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8649 | |
8650 | return (u64) tg->shares; | |
8651 | } | |
6d6bc0ad | 8652 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8653 | |
052f1dc7 | 8654 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 8655 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 8656 | s64 val) |
6f505b16 | 8657 | { |
06ecb27c | 8658 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
8659 | } |
8660 | ||
06ecb27c | 8661 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 8662 | { |
06ecb27c | 8663 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 8664 | } |
d0b27fa7 PZ |
8665 | |
8666 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
8667 | u64 rt_period_us) | |
8668 | { | |
8669 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
8670 | } | |
8671 | ||
8672 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
8673 | { | |
8674 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
8675 | } | |
6d6bc0ad | 8676 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8677 | |
fe5c7cc2 | 8678 | static struct cftype cpu_files[] = { |
052f1dc7 | 8679 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8680 | { |
8681 | .name = "shares", | |
f4c753b7 PM |
8682 | .read_u64 = cpu_shares_read_u64, |
8683 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8684 | }, |
052f1dc7 PZ |
8685 | #endif |
8686 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 8687 | { |
9f0c1e56 | 8688 | .name = "rt_runtime_us", |
06ecb27c PM |
8689 | .read_s64 = cpu_rt_runtime_read, |
8690 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8691 | }, |
d0b27fa7 PZ |
8692 | { |
8693 | .name = "rt_period_us", | |
f4c753b7 PM |
8694 | .read_u64 = cpu_rt_period_read_uint, |
8695 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8696 | }, |
052f1dc7 | 8697 | #endif |
68318b8e SV |
8698 | }; |
8699 | ||
8700 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
8701 | { | |
fe5c7cc2 | 8702 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
8703 | } |
8704 | ||
8705 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
8706 | .name = "cpu", |
8707 | .create = cpu_cgroup_create, | |
8708 | .destroy = cpu_cgroup_destroy, | |
8709 | .can_attach = cpu_cgroup_can_attach, | |
8710 | .attach = cpu_cgroup_attach, | |
8711 | .populate = cpu_cgroup_populate, | |
8712 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
8713 | .early_init = 1, |
8714 | }; | |
8715 | ||
052f1dc7 | 8716 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
8717 | |
8718 | #ifdef CONFIG_CGROUP_CPUACCT | |
8719 | ||
8720 | /* | |
8721 | * CPU accounting code for task groups. | |
8722 | * | |
8723 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
8724 | * (balbir@in.ibm.com). | |
8725 | */ | |
8726 | ||
934352f2 | 8727 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
8728 | struct cpuacct { |
8729 | struct cgroup_subsys_state css; | |
8730 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 8731 | u64 __percpu *cpuusage; |
ef12fefa | 8732 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 8733 | struct cpuacct *parent; |
d842de87 SV |
8734 | }; |
8735 | ||
8736 | struct cgroup_subsys cpuacct_subsys; | |
8737 | ||
8738 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 8739 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 8740 | { |
32cd756a | 8741 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
8742 | struct cpuacct, css); |
8743 | } | |
8744 | ||
8745 | /* return cpu accounting group to which this task belongs */ | |
8746 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
8747 | { | |
8748 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
8749 | struct cpuacct, css); | |
8750 | } | |
8751 | ||
8752 | /* create a new cpu accounting group */ | |
8753 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 8754 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
8755 | { |
8756 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 8757 | int i; |
d842de87 SV |
8758 | |
8759 | if (!ca) | |
ef12fefa | 8760 | goto out; |
d842de87 SV |
8761 | |
8762 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
8763 | if (!ca->cpuusage) |
8764 | goto out_free_ca; | |
8765 | ||
8766 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
8767 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
8768 | goto out_free_counters; | |
d842de87 | 8769 | |
934352f2 BR |
8770 | if (cgrp->parent) |
8771 | ca->parent = cgroup_ca(cgrp->parent); | |
8772 | ||
d842de87 | 8773 | return &ca->css; |
ef12fefa BR |
8774 | |
8775 | out_free_counters: | |
8776 | while (--i >= 0) | |
8777 | percpu_counter_destroy(&ca->cpustat[i]); | |
8778 | free_percpu(ca->cpuusage); | |
8779 | out_free_ca: | |
8780 | kfree(ca); | |
8781 | out: | |
8782 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
8783 | } |
8784 | ||
8785 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 8786 | static void |
32cd756a | 8787 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8788 | { |
32cd756a | 8789 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 8790 | int i; |
d842de87 | 8791 | |
ef12fefa BR |
8792 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
8793 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
8794 | free_percpu(ca->cpuusage); |
8795 | kfree(ca); | |
8796 | } | |
8797 | ||
720f5498 KC |
8798 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
8799 | { | |
b36128c8 | 8800 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8801 | u64 data; |
8802 | ||
8803 | #ifndef CONFIG_64BIT | |
8804 | /* | |
8805 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
8806 | */ | |
05fa785c | 8807 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8808 | data = *cpuusage; |
05fa785c | 8809 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8810 | #else |
8811 | data = *cpuusage; | |
8812 | #endif | |
8813 | ||
8814 | return data; | |
8815 | } | |
8816 | ||
8817 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
8818 | { | |
b36128c8 | 8819 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8820 | |
8821 | #ifndef CONFIG_64BIT | |
8822 | /* | |
8823 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
8824 | */ | |
05fa785c | 8825 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8826 | *cpuusage = val; |
05fa785c | 8827 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8828 | #else |
8829 | *cpuusage = val; | |
8830 | #endif | |
8831 | } | |
8832 | ||
d842de87 | 8833 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 8834 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 8835 | { |
32cd756a | 8836 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
8837 | u64 totalcpuusage = 0; |
8838 | int i; | |
8839 | ||
720f5498 KC |
8840 | for_each_present_cpu(i) |
8841 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
8842 | |
8843 | return totalcpuusage; | |
8844 | } | |
8845 | ||
0297b803 DG |
8846 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
8847 | u64 reset) | |
8848 | { | |
8849 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8850 | int err = 0; | |
8851 | int i; | |
8852 | ||
8853 | if (reset) { | |
8854 | err = -EINVAL; | |
8855 | goto out; | |
8856 | } | |
8857 | ||
720f5498 KC |
8858 | for_each_present_cpu(i) |
8859 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 8860 | |
0297b803 DG |
8861 | out: |
8862 | return err; | |
8863 | } | |
8864 | ||
e9515c3c KC |
8865 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
8866 | struct seq_file *m) | |
8867 | { | |
8868 | struct cpuacct *ca = cgroup_ca(cgroup); | |
8869 | u64 percpu; | |
8870 | int i; | |
8871 | ||
8872 | for_each_present_cpu(i) { | |
8873 | percpu = cpuacct_cpuusage_read(ca, i); | |
8874 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
8875 | } | |
8876 | seq_printf(m, "\n"); | |
8877 | return 0; | |
8878 | } | |
8879 | ||
ef12fefa BR |
8880 | static const char *cpuacct_stat_desc[] = { |
8881 | [CPUACCT_STAT_USER] = "user", | |
8882 | [CPUACCT_STAT_SYSTEM] = "system", | |
8883 | }; | |
8884 | ||
8885 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
8886 | struct cgroup_map_cb *cb) | |
8887 | { | |
8888 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8889 | int i; | |
8890 | ||
8891 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
8892 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
8893 | val = cputime64_to_clock_t(val); | |
8894 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
8895 | } | |
8896 | return 0; | |
8897 | } | |
8898 | ||
d842de87 SV |
8899 | static struct cftype files[] = { |
8900 | { | |
8901 | .name = "usage", | |
f4c753b7 PM |
8902 | .read_u64 = cpuusage_read, |
8903 | .write_u64 = cpuusage_write, | |
d842de87 | 8904 | }, |
e9515c3c KC |
8905 | { |
8906 | .name = "usage_percpu", | |
8907 | .read_seq_string = cpuacct_percpu_seq_read, | |
8908 | }, | |
ef12fefa BR |
8909 | { |
8910 | .name = "stat", | |
8911 | .read_map = cpuacct_stats_show, | |
8912 | }, | |
d842de87 SV |
8913 | }; |
8914 | ||
32cd756a | 8915 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8916 | { |
32cd756a | 8917 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
8918 | } |
8919 | ||
8920 | /* | |
8921 | * charge this task's execution time to its accounting group. | |
8922 | * | |
8923 | * called with rq->lock held. | |
8924 | */ | |
8925 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
8926 | { | |
8927 | struct cpuacct *ca; | |
934352f2 | 8928 | int cpu; |
d842de87 | 8929 | |
c40c6f85 | 8930 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
8931 | return; |
8932 | ||
934352f2 | 8933 | cpu = task_cpu(tsk); |
a18b83b7 BR |
8934 | |
8935 | rcu_read_lock(); | |
8936 | ||
d842de87 | 8937 | ca = task_ca(tsk); |
d842de87 | 8938 | |
934352f2 | 8939 | for (; ca; ca = ca->parent) { |
b36128c8 | 8940 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
8941 | *cpuusage += cputime; |
8942 | } | |
a18b83b7 BR |
8943 | |
8944 | rcu_read_unlock(); | |
d842de87 SV |
8945 | } |
8946 | ||
fa535a77 AB |
8947 | /* |
8948 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
8949 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
8950 | * percpu_counter_add with values large enough to always overflow the | |
8951 | * per cpu batch limit causing bad SMP scalability. | |
8952 | * | |
8953 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
8954 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
8955 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
8956 | */ | |
8957 | #ifdef CONFIG_SMP | |
8958 | #define CPUACCT_BATCH \ | |
8959 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
8960 | #else | |
8961 | #define CPUACCT_BATCH 0 | |
8962 | #endif | |
8963 | ||
ef12fefa BR |
8964 | /* |
8965 | * Charge the system/user time to the task's accounting group. | |
8966 | */ | |
8967 | static void cpuacct_update_stats(struct task_struct *tsk, | |
8968 | enum cpuacct_stat_index idx, cputime_t val) | |
8969 | { | |
8970 | struct cpuacct *ca; | |
fa535a77 | 8971 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
8972 | |
8973 | if (unlikely(!cpuacct_subsys.active)) | |
8974 | return; | |
8975 | ||
8976 | rcu_read_lock(); | |
8977 | ca = task_ca(tsk); | |
8978 | ||
8979 | do { | |
fa535a77 | 8980 | __percpu_counter_add(&ca->cpustat[idx], val, batch); |
ef12fefa BR |
8981 | ca = ca->parent; |
8982 | } while (ca); | |
8983 | rcu_read_unlock(); | |
8984 | } | |
8985 | ||
d842de87 SV |
8986 | struct cgroup_subsys cpuacct_subsys = { |
8987 | .name = "cpuacct", | |
8988 | .create = cpuacct_create, | |
8989 | .destroy = cpuacct_destroy, | |
8990 | .populate = cpuacct_populate, | |
8991 | .subsys_id = cpuacct_subsys_id, | |
8992 | }; | |
8993 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
8994 | |
8995 | #ifndef CONFIG_SMP | |
8996 | ||
8997 | int rcu_expedited_torture_stats(char *page) | |
8998 | { | |
8999 | return 0; | |
9000 | } | |
9001 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
9002 | ||
9003 | void synchronize_sched_expedited(void) | |
9004 | { | |
9005 | } | |
9006 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
9007 | ||
9008 | #else /* #ifndef CONFIG_SMP */ | |
9009 | ||
9010 | static DEFINE_PER_CPU(struct migration_req, rcu_migration_req); | |
9011 | static DEFINE_MUTEX(rcu_sched_expedited_mutex); | |
9012 | ||
9013 | #define RCU_EXPEDITED_STATE_POST -2 | |
9014 | #define RCU_EXPEDITED_STATE_IDLE -1 | |
9015 | ||
9016 | static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
9017 | ||
9018 | int rcu_expedited_torture_stats(char *page) | |
9019 | { | |
9020 | int cnt = 0; | |
9021 | int cpu; | |
9022 | ||
9023 | cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state); | |
9024 | for_each_online_cpu(cpu) { | |
9025 | cnt += sprintf(&page[cnt], " %d:%d", | |
9026 | cpu, per_cpu(rcu_migration_req, cpu).dest_cpu); | |
9027 | } | |
9028 | cnt += sprintf(&page[cnt], "\n"); | |
9029 | return cnt; | |
9030 | } | |
9031 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
9032 | ||
9033 | static long synchronize_sched_expedited_count; | |
9034 | ||
9035 | /* | |
9036 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
9037 | * approach to force grace period to end quickly. This consumes | |
9038 | * significant time on all CPUs, and is thus not recommended for | |
9039 | * any sort of common-case code. | |
9040 | * | |
9041 | * Note that it is illegal to call this function while holding any | |
9042 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
9043 | * observe this restriction will result in deadlock. | |
9044 | */ | |
9045 | void synchronize_sched_expedited(void) | |
9046 | { | |
9047 | int cpu; | |
9048 | unsigned long flags; | |
9049 | bool need_full_sync = 0; | |
9050 | struct rq *rq; | |
9051 | struct migration_req *req; | |
9052 | long snap; | |
9053 | int trycount = 0; | |
9054 | ||
9055 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
9056 | snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1; | |
9057 | get_online_cpus(); | |
9058 | while (!mutex_trylock(&rcu_sched_expedited_mutex)) { | |
9059 | put_online_cpus(); | |
9060 | if (trycount++ < 10) | |
9061 | udelay(trycount * num_online_cpus()); | |
9062 | else { | |
9063 | synchronize_sched(); | |
9064 | return; | |
9065 | } | |
9066 | if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) { | |
9067 | smp_mb(); /* ensure test happens before caller kfree */ | |
9068 | return; | |
9069 | } | |
9070 | get_online_cpus(); | |
9071 | } | |
9072 | rcu_expedited_state = RCU_EXPEDITED_STATE_POST; | |
9073 | for_each_online_cpu(cpu) { | |
9074 | rq = cpu_rq(cpu); | |
9075 | req = &per_cpu(rcu_migration_req, cpu); | |
9076 | init_completion(&req->done); | |
9077 | req->task = NULL; | |
9078 | req->dest_cpu = RCU_MIGRATION_NEED_QS; | |
05fa785c | 9079 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf | 9080 | list_add(&req->list, &rq->migration_queue); |
05fa785c | 9081 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
9082 | wake_up_process(rq->migration_thread); |
9083 | } | |
9084 | for_each_online_cpu(cpu) { | |
9085 | rcu_expedited_state = cpu; | |
9086 | req = &per_cpu(rcu_migration_req, cpu); | |
9087 | rq = cpu_rq(cpu); | |
9088 | wait_for_completion(&req->done); | |
05fa785c | 9089 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf PM |
9090 | if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC)) |
9091 | need_full_sync = 1; | |
9092 | req->dest_cpu = RCU_MIGRATION_IDLE; | |
05fa785c | 9093 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
9094 | } |
9095 | rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
956539b7 | 9096 | synchronize_sched_expedited_count++; |
03b042bf PM |
9097 | mutex_unlock(&rcu_sched_expedited_mutex); |
9098 | put_online_cpus(); | |
9099 | if (need_full_sync) | |
9100 | synchronize_sched(); | |
9101 | } | |
9102 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
9103 | ||
9104 | #endif /* #else #ifndef CONFIG_SMP */ |