]>
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> | |
b5aadf7f | 58 | #include <linux/proc_fs.h> |
1da177e4 | 59 | #include <linux/seq_file.h> |
969c7921 | 60 | #include <linux/stop_machine.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> |
5a0e3ad6 | 74 | #include <linux/slab.h> |
1da177e4 | 75 | |
5517d86b | 76 | #include <asm/tlb.h> |
838225b4 | 77 | #include <asm/irq_regs.h> |
1da177e4 | 78 | |
6e0534f2 GH |
79 | #include "sched_cpupri.h" |
80 | ||
a8d154b0 | 81 | #define CREATE_TRACE_POINTS |
ad8d75ff | 82 | #include <trace/events/sched.h> |
a8d154b0 | 83 | |
1da177e4 LT |
84 | /* |
85 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
86 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
87 | * and back. | |
88 | */ | |
89 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
90 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
91 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
92 | ||
93 | /* | |
94 | * 'User priority' is the nice value converted to something we | |
95 | * can work with better when scaling various scheduler parameters, | |
96 | * it's a [ 0 ... 39 ] range. | |
97 | */ | |
98 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
99 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
100 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
101 | ||
102 | /* | |
d7876a08 | 103 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 104 | */ |
d6322faf | 105 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 106 | |
6aa645ea IM |
107 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
108 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
109 | ||
1da177e4 LT |
110 | /* |
111 | * These are the 'tuning knobs' of the scheduler: | |
112 | * | |
a4ec24b4 | 113 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
114 | * Timeslices get refilled after they expire. |
115 | */ | |
1da177e4 | 116 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 117 | |
d0b27fa7 PZ |
118 | /* |
119 | * single value that denotes runtime == period, ie unlimited time. | |
120 | */ | |
121 | #define RUNTIME_INF ((u64)~0ULL) | |
122 | ||
e05606d3 IM |
123 | static inline int rt_policy(int policy) |
124 | { | |
3f33a7ce | 125 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
126 | return 1; |
127 | return 0; | |
128 | } | |
129 | ||
130 | static inline int task_has_rt_policy(struct task_struct *p) | |
131 | { | |
132 | return rt_policy(p->policy); | |
133 | } | |
134 | ||
1da177e4 | 135 | /* |
6aa645ea | 136 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 137 | */ |
6aa645ea IM |
138 | struct rt_prio_array { |
139 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
140 | struct list_head queue[MAX_RT_PRIO]; | |
141 | }; | |
142 | ||
d0b27fa7 | 143 | struct rt_bandwidth { |
ea736ed5 | 144 | /* nests inside the rq lock: */ |
0986b11b | 145 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
146 | ktime_t rt_period; |
147 | u64 rt_runtime; | |
148 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
149 | }; |
150 | ||
151 | static struct rt_bandwidth def_rt_bandwidth; | |
152 | ||
153 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
154 | ||
155 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
156 | { | |
157 | struct rt_bandwidth *rt_b = | |
158 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
159 | ktime_t now; | |
160 | int overrun; | |
161 | int idle = 0; | |
162 | ||
163 | for (;;) { | |
164 | now = hrtimer_cb_get_time(timer); | |
165 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
166 | ||
167 | if (!overrun) | |
168 | break; | |
169 | ||
170 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
171 | } | |
172 | ||
173 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
174 | } | |
175 | ||
176 | static | |
177 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
178 | { | |
179 | rt_b->rt_period = ns_to_ktime(period); | |
180 | rt_b->rt_runtime = runtime; | |
181 | ||
0986b11b | 182 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 183 | |
d0b27fa7 PZ |
184 | hrtimer_init(&rt_b->rt_period_timer, |
185 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
186 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
187 | } |
188 | ||
c8bfff6d KH |
189 | static inline int rt_bandwidth_enabled(void) |
190 | { | |
191 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
192 | } |
193 | ||
194 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
195 | { | |
196 | ktime_t now; | |
197 | ||
cac64d00 | 198 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
199 | return; |
200 | ||
201 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
202 | return; | |
203 | ||
0986b11b | 204 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 205 | for (;;) { |
7f1e2ca9 PZ |
206 | unsigned long delta; |
207 | ktime_t soft, hard; | |
208 | ||
d0b27fa7 PZ |
209 | if (hrtimer_active(&rt_b->rt_period_timer)) |
210 | break; | |
211 | ||
212 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
213 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
214 | |
215 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
216 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
217 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
218 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 219 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 | 220 | } |
0986b11b | 221 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
222 | } |
223 | ||
224 | #ifdef CONFIG_RT_GROUP_SCHED | |
225 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
226 | { | |
227 | hrtimer_cancel(&rt_b->rt_period_timer); | |
228 | } | |
229 | #endif | |
230 | ||
712555ee HC |
231 | /* |
232 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
233 | * detach_destroy_domains and partition_sched_domains. | |
234 | */ | |
235 | static DEFINE_MUTEX(sched_domains_mutex); | |
236 | ||
7c941438 | 237 | #ifdef CONFIG_CGROUP_SCHED |
29f59db3 | 238 | |
68318b8e SV |
239 | #include <linux/cgroup.h> |
240 | ||
29f59db3 SV |
241 | struct cfs_rq; |
242 | ||
6f505b16 PZ |
243 | static LIST_HEAD(task_groups); |
244 | ||
29f59db3 | 245 | /* task group related information */ |
4cf86d77 | 246 | struct task_group { |
68318b8e | 247 | struct cgroup_subsys_state css; |
6c415b92 | 248 | |
052f1dc7 | 249 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
250 | /* schedulable entities of this group on each cpu */ |
251 | struct sched_entity **se; | |
252 | /* runqueue "owned" by this group on each cpu */ | |
253 | struct cfs_rq **cfs_rq; | |
254 | unsigned long shares; | |
052f1dc7 PZ |
255 | #endif |
256 | ||
257 | #ifdef CONFIG_RT_GROUP_SCHED | |
258 | struct sched_rt_entity **rt_se; | |
259 | struct rt_rq **rt_rq; | |
260 | ||
d0b27fa7 | 261 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 262 | #endif |
6b2d7700 | 263 | |
ae8393e5 | 264 | struct rcu_head rcu; |
6f505b16 | 265 | struct list_head list; |
f473aa5e PZ |
266 | |
267 | struct task_group *parent; | |
268 | struct list_head siblings; | |
269 | struct list_head children; | |
29f59db3 SV |
270 | }; |
271 | ||
eff766a6 | 272 | #define root_task_group init_task_group |
6f505b16 | 273 | |
8ed36996 | 274 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
275 | * a task group's cpu shares. |
276 | */ | |
8ed36996 | 277 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 278 | |
e9036b36 CG |
279 | #ifdef CONFIG_FAIR_GROUP_SCHED |
280 | ||
57310a98 PZ |
281 | #ifdef CONFIG_SMP |
282 | static int root_task_group_empty(void) | |
283 | { | |
284 | return list_empty(&root_task_group.children); | |
285 | } | |
286 | #endif | |
287 | ||
052f1dc7 | 288 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 289 | |
cb4ad1ff | 290 | /* |
2e084786 LJ |
291 | * A weight of 0 or 1 can cause arithmetics problems. |
292 | * A weight of a cfs_rq is the sum of weights of which entities | |
293 | * are queued on this cfs_rq, so a weight of a entity should not be | |
294 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
295 | * (The default weight is 1024 - so there's no practical |
296 | * limitation from this.) | |
297 | */ | |
18d95a28 | 298 | #define MIN_SHARES 2 |
2e084786 | 299 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 300 | |
052f1dc7 PZ |
301 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
302 | #endif | |
303 | ||
29f59db3 | 304 | /* Default task group. |
3a252015 | 305 | * Every task in system belong to this group at bootup. |
29f59db3 | 306 | */ |
434d53b0 | 307 | struct task_group init_task_group; |
29f59db3 SV |
308 | |
309 | /* return group to which a task belongs */ | |
4cf86d77 | 310 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 311 | { |
4cf86d77 | 312 | struct task_group *tg; |
9b5b7751 | 313 | |
7c941438 | 314 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
315 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
316 | struct task_group, css); | |
24e377a8 | 317 | #else |
41a2d6cf | 318 | tg = &init_task_group; |
24e377a8 | 319 | #endif |
9b5b7751 | 320 | return tg; |
29f59db3 SV |
321 | } |
322 | ||
323 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 324 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 325 | { |
8b08ca52 PZ |
326 | /* |
327 | * Strictly speaking this rcu_read_lock() is not needed since the | |
328 | * task_group is tied to the cgroup, which in turn can never go away | |
329 | * as long as there are tasks attached to it. | |
330 | * | |
331 | * However since task_group() uses task_subsys_state() which is an | |
332 | * rcu_dereference() user, this quiets CONFIG_PROVE_RCU. | |
333 | */ | |
334 | rcu_read_lock(); | |
052f1dc7 | 335 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
336 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
337 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 338 | #endif |
6f505b16 | 339 | |
052f1dc7 | 340 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
341 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
342 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 343 | #endif |
8b08ca52 | 344 | rcu_read_unlock(); |
29f59db3 SV |
345 | } |
346 | ||
347 | #else | |
348 | ||
6f505b16 | 349 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
350 | static inline struct task_group *task_group(struct task_struct *p) |
351 | { | |
352 | return NULL; | |
353 | } | |
29f59db3 | 354 | |
7c941438 | 355 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 356 | |
6aa645ea IM |
357 | /* CFS-related fields in a runqueue */ |
358 | struct cfs_rq { | |
359 | struct load_weight load; | |
360 | unsigned long nr_running; | |
361 | ||
6aa645ea | 362 | u64 exec_clock; |
e9acbff6 | 363 | u64 min_vruntime; |
6aa645ea IM |
364 | |
365 | struct rb_root tasks_timeline; | |
366 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
367 | |
368 | struct list_head tasks; | |
369 | struct list_head *balance_iterator; | |
370 | ||
371 | /* | |
372 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
373 | * It is set to NULL otherwise (i.e when none are currently running). |
374 | */ | |
4793241b | 375 | struct sched_entity *curr, *next, *last; |
ddc97297 | 376 | |
5ac5c4d6 | 377 | unsigned int nr_spread_over; |
ddc97297 | 378 | |
62160e3f | 379 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
380 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
381 | ||
41a2d6cf IM |
382 | /* |
383 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
384 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
385 | * (like users, containers etc.) | |
386 | * | |
387 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
388 | * list is used during load balance. | |
389 | */ | |
41a2d6cf IM |
390 | struct list_head leaf_cfs_rq_list; |
391 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
392 | |
393 | #ifdef CONFIG_SMP | |
c09595f6 | 394 | /* |
c8cba857 | 395 | * the part of load.weight contributed by tasks |
c09595f6 | 396 | */ |
c8cba857 | 397 | unsigned long task_weight; |
c09595f6 | 398 | |
c8cba857 PZ |
399 | /* |
400 | * h_load = weight * f(tg) | |
401 | * | |
402 | * Where f(tg) is the recursive weight fraction assigned to | |
403 | * this group. | |
404 | */ | |
405 | unsigned long h_load; | |
c09595f6 | 406 | |
c8cba857 PZ |
407 | /* |
408 | * this cpu's part of tg->shares | |
409 | */ | |
410 | unsigned long shares; | |
f1d239f7 PZ |
411 | |
412 | /* | |
413 | * load.weight at the time we set shares | |
414 | */ | |
415 | unsigned long rq_weight; | |
c09595f6 | 416 | #endif |
6aa645ea IM |
417 | #endif |
418 | }; | |
1da177e4 | 419 | |
6aa645ea IM |
420 | /* Real-Time classes' related field in a runqueue: */ |
421 | struct rt_rq { | |
422 | struct rt_prio_array active; | |
63489e45 | 423 | unsigned long rt_nr_running; |
052f1dc7 | 424 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
425 | struct { |
426 | int curr; /* highest queued rt task prio */ | |
398a153b | 427 | #ifdef CONFIG_SMP |
e864c499 | 428 | int next; /* next highest */ |
398a153b | 429 | #endif |
e864c499 | 430 | } highest_prio; |
6f505b16 | 431 | #endif |
fa85ae24 | 432 | #ifdef CONFIG_SMP |
73fe6aae | 433 | unsigned long rt_nr_migratory; |
a1ba4d8b | 434 | unsigned long rt_nr_total; |
a22d7fc1 | 435 | int overloaded; |
917b627d | 436 | struct plist_head pushable_tasks; |
fa85ae24 | 437 | #endif |
6f505b16 | 438 | int rt_throttled; |
fa85ae24 | 439 | u64 rt_time; |
ac086bc2 | 440 | u64 rt_runtime; |
ea736ed5 | 441 | /* Nests inside the rq lock: */ |
0986b11b | 442 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 443 | |
052f1dc7 | 444 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
445 | unsigned long rt_nr_boosted; |
446 | ||
6f505b16 PZ |
447 | struct rq *rq; |
448 | struct list_head leaf_rt_rq_list; | |
449 | struct task_group *tg; | |
6f505b16 | 450 | #endif |
6aa645ea IM |
451 | }; |
452 | ||
57d885fe GH |
453 | #ifdef CONFIG_SMP |
454 | ||
455 | /* | |
456 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
457 | * variables. Each exclusive cpuset essentially defines an island domain by |
458 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
459 | * exclusive cpuset is created, we also create and attach a new root-domain |
460 | * object. | |
461 | * | |
57d885fe GH |
462 | */ |
463 | struct root_domain { | |
464 | atomic_t refcount; | |
c6c4927b RR |
465 | cpumask_var_t span; |
466 | cpumask_var_t online; | |
637f5085 | 467 | |
0eab9146 | 468 | /* |
637f5085 GH |
469 | * The "RT overload" flag: it gets set if a CPU has more than |
470 | * one runnable RT task. | |
471 | */ | |
c6c4927b | 472 | cpumask_var_t rto_mask; |
0eab9146 | 473 | atomic_t rto_count; |
6e0534f2 GH |
474 | #ifdef CONFIG_SMP |
475 | struct cpupri cpupri; | |
476 | #endif | |
57d885fe GH |
477 | }; |
478 | ||
dc938520 GH |
479 | /* |
480 | * By default the system creates a single root-domain with all cpus as | |
481 | * members (mimicking the global state we have today). | |
482 | */ | |
57d885fe GH |
483 | static struct root_domain def_root_domain; |
484 | ||
485 | #endif | |
486 | ||
1da177e4 LT |
487 | /* |
488 | * This is the main, per-CPU runqueue data structure. | |
489 | * | |
490 | * Locking rule: those places that want to lock multiple runqueues | |
491 | * (such as the load balancing or the thread migration code), lock | |
492 | * acquire operations must be ordered by ascending &runqueue. | |
493 | */ | |
70b97a7f | 494 | struct rq { |
d8016491 | 495 | /* runqueue lock: */ |
05fa785c | 496 | raw_spinlock_t lock; |
1da177e4 LT |
497 | |
498 | /* | |
499 | * nr_running and cpu_load should be in the same cacheline because | |
500 | * remote CPUs use both these fields when doing load calculation. | |
501 | */ | |
502 | unsigned long nr_running; | |
6aa645ea IM |
503 | #define CPU_LOAD_IDX_MAX 5 |
504 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
46cb4b7c | 505 | #ifdef CONFIG_NO_HZ |
39c0cbe2 | 506 | u64 nohz_stamp; |
46cb4b7c SS |
507 | unsigned char in_nohz_recently; |
508 | #endif | |
a64692a3 MG |
509 | unsigned int skip_clock_update; |
510 | ||
d8016491 IM |
511 | /* capture load from *all* tasks on this cpu: */ |
512 | struct load_weight load; | |
6aa645ea IM |
513 | unsigned long nr_load_updates; |
514 | u64 nr_switches; | |
515 | ||
516 | struct cfs_rq cfs; | |
6f505b16 | 517 | struct rt_rq rt; |
6f505b16 | 518 | |
6aa645ea | 519 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
520 | /* list of leaf cfs_rq on this cpu: */ |
521 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
522 | #endif |
523 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 524 | struct list_head leaf_rt_rq_list; |
1da177e4 | 525 | #endif |
1da177e4 LT |
526 | |
527 | /* | |
528 | * This is part of a global counter where only the total sum | |
529 | * over all CPUs matters. A task can increase this counter on | |
530 | * one CPU and if it got migrated afterwards it may decrease | |
531 | * it on another CPU. Always updated under the runqueue lock: | |
532 | */ | |
533 | unsigned long nr_uninterruptible; | |
534 | ||
36c8b586 | 535 | struct task_struct *curr, *idle; |
c9819f45 | 536 | unsigned long next_balance; |
1da177e4 | 537 | struct mm_struct *prev_mm; |
6aa645ea | 538 | |
3e51f33f | 539 | u64 clock; |
6aa645ea | 540 | |
1da177e4 LT |
541 | atomic_t nr_iowait; |
542 | ||
543 | #ifdef CONFIG_SMP | |
0eab9146 | 544 | struct root_domain *rd; |
1da177e4 LT |
545 | struct sched_domain *sd; |
546 | ||
a0a522ce | 547 | unsigned char idle_at_tick; |
1da177e4 | 548 | /* For active balancing */ |
3f029d3c | 549 | int post_schedule; |
1da177e4 LT |
550 | int active_balance; |
551 | int push_cpu; | |
969c7921 | 552 | struct cpu_stop_work active_balance_work; |
d8016491 IM |
553 | /* cpu of this runqueue: */ |
554 | int cpu; | |
1f11eb6a | 555 | int online; |
1da177e4 | 556 | |
a8a51d5e | 557 | unsigned long avg_load_per_task; |
1da177e4 | 558 | |
e9e9250b PZ |
559 | u64 rt_avg; |
560 | u64 age_stamp; | |
1b9508f6 MG |
561 | u64 idle_stamp; |
562 | u64 avg_idle; | |
1da177e4 LT |
563 | #endif |
564 | ||
dce48a84 TG |
565 | /* calc_load related fields */ |
566 | unsigned long calc_load_update; | |
567 | long calc_load_active; | |
568 | ||
8f4d37ec | 569 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
570 | #ifdef CONFIG_SMP |
571 | int hrtick_csd_pending; | |
572 | struct call_single_data hrtick_csd; | |
573 | #endif | |
8f4d37ec PZ |
574 | struct hrtimer hrtick_timer; |
575 | #endif | |
576 | ||
1da177e4 LT |
577 | #ifdef CONFIG_SCHEDSTATS |
578 | /* latency stats */ | |
579 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
580 | unsigned long long rq_cpu_time; |
581 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
582 | |
583 | /* sys_sched_yield() stats */ | |
480b9434 | 584 | unsigned int yld_count; |
1da177e4 LT |
585 | |
586 | /* schedule() stats */ | |
480b9434 KC |
587 | unsigned int sched_switch; |
588 | unsigned int sched_count; | |
589 | unsigned int sched_goidle; | |
1da177e4 LT |
590 | |
591 | /* try_to_wake_up() stats */ | |
480b9434 KC |
592 | unsigned int ttwu_count; |
593 | unsigned int ttwu_local; | |
b8efb561 IM |
594 | |
595 | /* BKL stats */ | |
480b9434 | 596 | unsigned int bkl_count; |
1da177e4 LT |
597 | #endif |
598 | }; | |
599 | ||
f34e3b61 | 600 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 601 | |
7d478721 PZ |
602 | static inline |
603 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) | |
dd41f596 | 604 | { |
7d478721 | 605 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); |
a64692a3 MG |
606 | |
607 | /* | |
608 | * A queue event has occurred, and we're going to schedule. In | |
609 | * this case, we can save a useless back to back clock update. | |
610 | */ | |
611 | if (test_tsk_need_resched(p)) | |
612 | rq->skip_clock_update = 1; | |
dd41f596 IM |
613 | } |
614 | ||
0a2966b4 CL |
615 | static inline int cpu_of(struct rq *rq) |
616 | { | |
617 | #ifdef CONFIG_SMP | |
618 | return rq->cpu; | |
619 | #else | |
620 | return 0; | |
621 | #endif | |
622 | } | |
623 | ||
497f0ab3 | 624 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d PM |
625 | rcu_dereference_check((p), \ |
626 | rcu_read_lock_sched_held() || \ | |
627 | lockdep_is_held(&sched_domains_mutex)) | |
628 | ||
674311d5 NP |
629 | /* |
630 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 631 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
632 | * |
633 | * The domain tree of any CPU may only be accessed from within | |
634 | * preempt-disabled sections. | |
635 | */ | |
48f24c4d | 636 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 637 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
638 | |
639 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
640 | #define this_rq() (&__get_cpu_var(runqueues)) | |
641 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
642 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 643 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 644 | |
aa9c4c0f | 645 | inline void update_rq_clock(struct rq *rq) |
3e51f33f | 646 | { |
a64692a3 MG |
647 | if (!rq->skip_clock_update) |
648 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
3e51f33f PZ |
649 | } |
650 | ||
bf5c91ba IM |
651 | /* |
652 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
653 | */ | |
654 | #ifdef CONFIG_SCHED_DEBUG | |
655 | # define const_debug __read_mostly | |
656 | #else | |
657 | # define const_debug static const | |
658 | #endif | |
659 | ||
017730c1 IM |
660 | /** |
661 | * runqueue_is_locked | |
e17b38bf | 662 | * @cpu: the processor in question. |
017730c1 IM |
663 | * |
664 | * Returns true if the current cpu runqueue is locked. | |
665 | * This interface allows printk to be called with the runqueue lock | |
666 | * held and know whether or not it is OK to wake up the klogd. | |
667 | */ | |
89f19f04 | 668 | int runqueue_is_locked(int cpu) |
017730c1 | 669 | { |
05fa785c | 670 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
671 | } |
672 | ||
bf5c91ba IM |
673 | /* |
674 | * Debugging: various feature bits | |
675 | */ | |
f00b45c1 PZ |
676 | |
677 | #define SCHED_FEAT(name, enabled) \ | |
678 | __SCHED_FEAT_##name , | |
679 | ||
bf5c91ba | 680 | enum { |
f00b45c1 | 681 | #include "sched_features.h" |
bf5c91ba IM |
682 | }; |
683 | ||
f00b45c1 PZ |
684 | #undef SCHED_FEAT |
685 | ||
686 | #define SCHED_FEAT(name, enabled) \ | |
687 | (1UL << __SCHED_FEAT_##name) * enabled | | |
688 | ||
bf5c91ba | 689 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
690 | #include "sched_features.h" |
691 | 0; | |
692 | ||
693 | #undef SCHED_FEAT | |
694 | ||
695 | #ifdef CONFIG_SCHED_DEBUG | |
696 | #define SCHED_FEAT(name, enabled) \ | |
697 | #name , | |
698 | ||
983ed7a6 | 699 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
700 | #include "sched_features.h" |
701 | NULL | |
702 | }; | |
703 | ||
704 | #undef SCHED_FEAT | |
705 | ||
34f3a814 | 706 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 707 | { |
f00b45c1 PZ |
708 | int i; |
709 | ||
710 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
711 | if (!(sysctl_sched_features & (1UL << i))) |
712 | seq_puts(m, "NO_"); | |
713 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 714 | } |
34f3a814 | 715 | seq_puts(m, "\n"); |
f00b45c1 | 716 | |
34f3a814 | 717 | return 0; |
f00b45c1 PZ |
718 | } |
719 | ||
720 | static ssize_t | |
721 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
722 | size_t cnt, loff_t *ppos) | |
723 | { | |
724 | char buf[64]; | |
725 | char *cmp = buf; | |
726 | int neg = 0; | |
727 | int i; | |
728 | ||
729 | if (cnt > 63) | |
730 | cnt = 63; | |
731 | ||
732 | if (copy_from_user(&buf, ubuf, cnt)) | |
733 | return -EFAULT; | |
734 | ||
735 | buf[cnt] = 0; | |
736 | ||
c24b7c52 | 737 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
738 | neg = 1; |
739 | cmp += 3; | |
740 | } | |
741 | ||
742 | for (i = 0; sched_feat_names[i]; i++) { | |
743 | int len = strlen(sched_feat_names[i]); | |
744 | ||
745 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
746 | if (neg) | |
747 | sysctl_sched_features &= ~(1UL << i); | |
748 | else | |
749 | sysctl_sched_features |= (1UL << i); | |
750 | break; | |
751 | } | |
752 | } | |
753 | ||
754 | if (!sched_feat_names[i]) | |
755 | return -EINVAL; | |
756 | ||
42994724 | 757 | *ppos += cnt; |
f00b45c1 PZ |
758 | |
759 | return cnt; | |
760 | } | |
761 | ||
34f3a814 LZ |
762 | static int sched_feat_open(struct inode *inode, struct file *filp) |
763 | { | |
764 | return single_open(filp, sched_feat_show, NULL); | |
765 | } | |
766 | ||
828c0950 | 767 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
768 | .open = sched_feat_open, |
769 | .write = sched_feat_write, | |
770 | .read = seq_read, | |
771 | .llseek = seq_lseek, | |
772 | .release = single_release, | |
f00b45c1 PZ |
773 | }; |
774 | ||
775 | static __init int sched_init_debug(void) | |
776 | { | |
f00b45c1 PZ |
777 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
778 | &sched_feat_fops); | |
779 | ||
780 | return 0; | |
781 | } | |
782 | late_initcall(sched_init_debug); | |
783 | ||
784 | #endif | |
785 | ||
786 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 787 | |
b82d9fdd PZ |
788 | /* |
789 | * Number of tasks to iterate in a single balance run. | |
790 | * Limited because this is done with IRQs disabled. | |
791 | */ | |
792 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
793 | ||
2398f2c6 PZ |
794 | /* |
795 | * ratelimit for updating the group shares. | |
55cd5340 | 796 | * default: 0.25ms |
2398f2c6 | 797 | */ |
55cd5340 | 798 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
0bcdcf28 | 799 | unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 800 | |
ffda12a1 PZ |
801 | /* |
802 | * Inject some fuzzyness into changing the per-cpu group shares | |
803 | * this avoids remote rq-locks at the expense of fairness. | |
804 | * default: 4 | |
805 | */ | |
806 | unsigned int sysctl_sched_shares_thresh = 4; | |
807 | ||
e9e9250b PZ |
808 | /* |
809 | * period over which we average the RT time consumption, measured | |
810 | * in ms. | |
811 | * | |
812 | * default: 1s | |
813 | */ | |
814 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
815 | ||
fa85ae24 | 816 | /* |
9f0c1e56 | 817 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
818 | * default: 1s |
819 | */ | |
9f0c1e56 | 820 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 821 | |
6892b75e IM |
822 | static __read_mostly int scheduler_running; |
823 | ||
9f0c1e56 PZ |
824 | /* |
825 | * part of the period that we allow rt tasks to run in us. | |
826 | * default: 0.95s | |
827 | */ | |
828 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 829 | |
d0b27fa7 PZ |
830 | static inline u64 global_rt_period(void) |
831 | { | |
832 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
833 | } | |
834 | ||
835 | static inline u64 global_rt_runtime(void) | |
836 | { | |
e26873bb | 837 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
838 | return RUNTIME_INF; |
839 | ||
840 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
841 | } | |
fa85ae24 | 842 | |
1da177e4 | 843 | #ifndef prepare_arch_switch |
4866cde0 NP |
844 | # define prepare_arch_switch(next) do { } while (0) |
845 | #endif | |
846 | #ifndef finish_arch_switch | |
847 | # define finish_arch_switch(prev) do { } while (0) | |
848 | #endif | |
849 | ||
051a1d1a DA |
850 | static inline int task_current(struct rq *rq, struct task_struct *p) |
851 | { | |
852 | return rq->curr == p; | |
853 | } | |
854 | ||
4866cde0 | 855 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 856 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 857 | { |
051a1d1a | 858 | return task_current(rq, p); |
4866cde0 NP |
859 | } |
860 | ||
70b97a7f | 861 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
862 | { |
863 | } | |
864 | ||
70b97a7f | 865 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 866 | { |
da04c035 IM |
867 | #ifdef CONFIG_DEBUG_SPINLOCK |
868 | /* this is a valid case when another task releases the spinlock */ | |
869 | rq->lock.owner = current; | |
870 | #endif | |
8a25d5de IM |
871 | /* |
872 | * If we are tracking spinlock dependencies then we have to | |
873 | * fix up the runqueue lock - which gets 'carried over' from | |
874 | * prev into current: | |
875 | */ | |
876 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
877 | ||
05fa785c | 878 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
879 | } |
880 | ||
881 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 882 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
883 | { |
884 | #ifdef CONFIG_SMP | |
885 | return p->oncpu; | |
886 | #else | |
051a1d1a | 887 | return task_current(rq, p); |
4866cde0 NP |
888 | #endif |
889 | } | |
890 | ||
70b97a7f | 891 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
892 | { |
893 | #ifdef CONFIG_SMP | |
894 | /* | |
895 | * We can optimise this out completely for !SMP, because the | |
896 | * SMP rebalancing from interrupt is the only thing that cares | |
897 | * here. | |
898 | */ | |
899 | next->oncpu = 1; | |
900 | #endif | |
901 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 902 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 903 | #else |
05fa785c | 904 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
905 | #endif |
906 | } | |
907 | ||
70b97a7f | 908 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
909 | { |
910 | #ifdef CONFIG_SMP | |
911 | /* | |
912 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
913 | * We must ensure this doesn't happen until the switch is completely | |
914 | * finished. | |
915 | */ | |
916 | smp_wmb(); | |
917 | prev->oncpu = 0; | |
918 | #endif | |
919 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
920 | local_irq_enable(); | |
1da177e4 | 921 | #endif |
4866cde0 NP |
922 | } |
923 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 924 | |
0970d299 | 925 | /* |
65cc8e48 PZ |
926 | * Check whether the task is waking, we use this to synchronize ->cpus_allowed |
927 | * against ttwu(). | |
0970d299 PZ |
928 | */ |
929 | static inline int task_is_waking(struct task_struct *p) | |
930 | { | |
0017d735 | 931 | return unlikely(p->state == TASK_WAKING); |
0970d299 PZ |
932 | } |
933 | ||
b29739f9 IM |
934 | /* |
935 | * __task_rq_lock - lock the runqueue a given task resides on. | |
936 | * Must be called interrupts disabled. | |
937 | */ | |
70b97a7f | 938 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
939 | __acquires(rq->lock) |
940 | { | |
0970d299 PZ |
941 | struct rq *rq; |
942 | ||
3a5c359a | 943 | for (;;) { |
0970d299 | 944 | rq = task_rq(p); |
05fa785c | 945 | raw_spin_lock(&rq->lock); |
65cc8e48 | 946 | if (likely(rq == task_rq(p))) |
3a5c359a | 947 | return rq; |
05fa785c | 948 | raw_spin_unlock(&rq->lock); |
b29739f9 | 949 | } |
b29739f9 IM |
950 | } |
951 | ||
1da177e4 LT |
952 | /* |
953 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 954 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
955 | * explicitly disabling preemption. |
956 | */ | |
70b97a7f | 957 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
958 | __acquires(rq->lock) |
959 | { | |
70b97a7f | 960 | struct rq *rq; |
1da177e4 | 961 | |
3a5c359a AK |
962 | for (;;) { |
963 | local_irq_save(*flags); | |
964 | rq = task_rq(p); | |
05fa785c | 965 | raw_spin_lock(&rq->lock); |
65cc8e48 | 966 | if (likely(rq == task_rq(p))) |
3a5c359a | 967 | return rq; |
05fa785c | 968 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 969 | } |
1da177e4 LT |
970 | } |
971 | ||
a9957449 | 972 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
973 | __releases(rq->lock) |
974 | { | |
05fa785c | 975 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
976 | } |
977 | ||
70b97a7f | 978 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
979 | __releases(rq->lock) |
980 | { | |
05fa785c | 981 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 LT |
982 | } |
983 | ||
1da177e4 | 984 | /* |
cc2a73b5 | 985 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 986 | */ |
a9957449 | 987 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
988 | __acquires(rq->lock) |
989 | { | |
70b97a7f | 990 | struct rq *rq; |
1da177e4 LT |
991 | |
992 | local_irq_disable(); | |
993 | rq = this_rq(); | |
05fa785c | 994 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
995 | |
996 | return rq; | |
997 | } | |
998 | ||
8f4d37ec PZ |
999 | #ifdef CONFIG_SCHED_HRTICK |
1000 | /* | |
1001 | * Use HR-timers to deliver accurate preemption points. | |
1002 | * | |
1003 | * Its all a bit involved since we cannot program an hrt while holding the | |
1004 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1005 | * reschedule event. | |
1006 | * | |
1007 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1008 | * rq->lock. | |
1009 | */ | |
8f4d37ec PZ |
1010 | |
1011 | /* | |
1012 | * Use hrtick when: | |
1013 | * - enabled by features | |
1014 | * - hrtimer is actually high res | |
1015 | */ | |
1016 | static inline int hrtick_enabled(struct rq *rq) | |
1017 | { | |
1018 | if (!sched_feat(HRTICK)) | |
1019 | return 0; | |
ba42059f | 1020 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1021 | return 0; |
8f4d37ec PZ |
1022 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1023 | } | |
1024 | ||
8f4d37ec PZ |
1025 | static void hrtick_clear(struct rq *rq) |
1026 | { | |
1027 | if (hrtimer_active(&rq->hrtick_timer)) | |
1028 | hrtimer_cancel(&rq->hrtick_timer); | |
1029 | } | |
1030 | ||
8f4d37ec PZ |
1031 | /* |
1032 | * High-resolution timer tick. | |
1033 | * Runs from hardirq context with interrupts disabled. | |
1034 | */ | |
1035 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1036 | { | |
1037 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1038 | ||
1039 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1040 | ||
05fa785c | 1041 | raw_spin_lock(&rq->lock); |
3e51f33f | 1042 | update_rq_clock(rq); |
8f4d37ec | 1043 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1044 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1045 | |
1046 | return HRTIMER_NORESTART; | |
1047 | } | |
1048 | ||
95e904c7 | 1049 | #ifdef CONFIG_SMP |
31656519 PZ |
1050 | /* |
1051 | * called from hardirq (IPI) context | |
1052 | */ | |
1053 | static void __hrtick_start(void *arg) | |
b328ca18 | 1054 | { |
31656519 | 1055 | struct rq *rq = arg; |
b328ca18 | 1056 | |
05fa785c | 1057 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1058 | hrtimer_restart(&rq->hrtick_timer); |
1059 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1060 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1061 | } |
1062 | ||
31656519 PZ |
1063 | /* |
1064 | * Called to set the hrtick timer state. | |
1065 | * | |
1066 | * called with rq->lock held and irqs disabled | |
1067 | */ | |
1068 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1069 | { |
31656519 PZ |
1070 | struct hrtimer *timer = &rq->hrtick_timer; |
1071 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1072 | |
cc584b21 | 1073 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1074 | |
1075 | if (rq == this_rq()) { | |
1076 | hrtimer_restart(timer); | |
1077 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1078 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1079 | rq->hrtick_csd_pending = 1; |
1080 | } | |
b328ca18 PZ |
1081 | } |
1082 | ||
1083 | static int | |
1084 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1085 | { | |
1086 | int cpu = (int)(long)hcpu; | |
1087 | ||
1088 | switch (action) { | |
1089 | case CPU_UP_CANCELED: | |
1090 | case CPU_UP_CANCELED_FROZEN: | |
1091 | case CPU_DOWN_PREPARE: | |
1092 | case CPU_DOWN_PREPARE_FROZEN: | |
1093 | case CPU_DEAD: | |
1094 | case CPU_DEAD_FROZEN: | |
31656519 | 1095 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1096 | return NOTIFY_OK; |
1097 | } | |
1098 | ||
1099 | return NOTIFY_DONE; | |
1100 | } | |
1101 | ||
fa748203 | 1102 | static __init void init_hrtick(void) |
b328ca18 PZ |
1103 | { |
1104 | hotcpu_notifier(hotplug_hrtick, 0); | |
1105 | } | |
31656519 PZ |
1106 | #else |
1107 | /* | |
1108 | * Called to set the hrtick timer state. | |
1109 | * | |
1110 | * called with rq->lock held and irqs disabled | |
1111 | */ | |
1112 | static void hrtick_start(struct rq *rq, u64 delay) | |
1113 | { | |
7f1e2ca9 | 1114 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1115 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1116 | } |
b328ca18 | 1117 | |
006c75f1 | 1118 | static inline void init_hrtick(void) |
8f4d37ec | 1119 | { |
8f4d37ec | 1120 | } |
31656519 | 1121 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1122 | |
31656519 | 1123 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1124 | { |
31656519 PZ |
1125 | #ifdef CONFIG_SMP |
1126 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1127 | |
31656519 PZ |
1128 | rq->hrtick_csd.flags = 0; |
1129 | rq->hrtick_csd.func = __hrtick_start; | |
1130 | rq->hrtick_csd.info = rq; | |
1131 | #endif | |
8f4d37ec | 1132 | |
31656519 PZ |
1133 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1134 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1135 | } |
006c75f1 | 1136 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1137 | static inline void hrtick_clear(struct rq *rq) |
1138 | { | |
1139 | } | |
1140 | ||
8f4d37ec PZ |
1141 | static inline void init_rq_hrtick(struct rq *rq) |
1142 | { | |
1143 | } | |
1144 | ||
b328ca18 PZ |
1145 | static inline void init_hrtick(void) |
1146 | { | |
1147 | } | |
006c75f1 | 1148 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1149 | |
c24d20db IM |
1150 | /* |
1151 | * resched_task - mark a task 'to be rescheduled now'. | |
1152 | * | |
1153 | * On UP this means the setting of the need_resched flag, on SMP it | |
1154 | * might also involve a cross-CPU call to trigger the scheduler on | |
1155 | * the target CPU. | |
1156 | */ | |
1157 | #ifdef CONFIG_SMP | |
1158 | ||
1159 | #ifndef tsk_is_polling | |
1160 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1161 | #endif | |
1162 | ||
31656519 | 1163 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1164 | { |
1165 | int cpu; | |
1166 | ||
05fa785c | 1167 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1168 | |
5ed0cec0 | 1169 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1170 | return; |
1171 | ||
5ed0cec0 | 1172 | set_tsk_need_resched(p); |
c24d20db IM |
1173 | |
1174 | cpu = task_cpu(p); | |
1175 | if (cpu == smp_processor_id()) | |
1176 | return; | |
1177 | ||
1178 | /* NEED_RESCHED must be visible before we test polling */ | |
1179 | smp_mb(); | |
1180 | if (!tsk_is_polling(p)) | |
1181 | smp_send_reschedule(cpu); | |
1182 | } | |
1183 | ||
1184 | static void resched_cpu(int cpu) | |
1185 | { | |
1186 | struct rq *rq = cpu_rq(cpu); | |
1187 | unsigned long flags; | |
1188 | ||
05fa785c | 1189 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1190 | return; |
1191 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1192 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1193 | } |
06d8308c TG |
1194 | |
1195 | #ifdef CONFIG_NO_HZ | |
1196 | /* | |
1197 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1198 | * idle CPU then this timer might expire before the next timer event | |
1199 | * which is scheduled to wake up that CPU. In case of a completely | |
1200 | * idle system the next event might even be infinite time into the | |
1201 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1202 | * leaves the inner idle loop so the newly added timer is taken into | |
1203 | * account when the CPU goes back to idle and evaluates the timer | |
1204 | * wheel for the next timer event. | |
1205 | */ | |
1206 | void wake_up_idle_cpu(int cpu) | |
1207 | { | |
1208 | struct rq *rq = cpu_rq(cpu); | |
1209 | ||
1210 | if (cpu == smp_processor_id()) | |
1211 | return; | |
1212 | ||
1213 | /* | |
1214 | * This is safe, as this function is called with the timer | |
1215 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1216 | * to idle and has not yet set rq->curr to idle then it will | |
1217 | * be serialized on the timer wheel base lock and take the new | |
1218 | * timer into account automatically. | |
1219 | */ | |
1220 | if (rq->curr != rq->idle) | |
1221 | return; | |
1222 | ||
1223 | /* | |
1224 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1225 | * lockless. The worst case is that the other CPU runs the | |
1226 | * idle task through an additional NOOP schedule() | |
1227 | */ | |
5ed0cec0 | 1228 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1229 | |
1230 | /* NEED_RESCHED must be visible before we test polling */ | |
1231 | smp_mb(); | |
1232 | if (!tsk_is_polling(rq->idle)) | |
1233 | smp_send_reschedule(cpu); | |
1234 | } | |
39c0cbe2 MG |
1235 | |
1236 | int nohz_ratelimit(int cpu) | |
1237 | { | |
1238 | struct rq *rq = cpu_rq(cpu); | |
1239 | u64 diff = rq->clock - rq->nohz_stamp; | |
1240 | ||
1241 | rq->nohz_stamp = rq->clock; | |
1242 | ||
1243 | return diff < (NSEC_PER_SEC / HZ) >> 1; | |
1244 | } | |
1245 | ||
6d6bc0ad | 1246 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1247 | |
e9e9250b PZ |
1248 | static u64 sched_avg_period(void) |
1249 | { | |
1250 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1251 | } | |
1252 | ||
1253 | static void sched_avg_update(struct rq *rq) | |
1254 | { | |
1255 | s64 period = sched_avg_period(); | |
1256 | ||
1257 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
1258 | rq->age_stamp += period; | |
1259 | rq->rt_avg /= 2; | |
1260 | } | |
1261 | } | |
1262 | ||
1263 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1264 | { | |
1265 | rq->rt_avg += rt_delta; | |
1266 | sched_avg_update(rq); | |
1267 | } | |
1268 | ||
6d6bc0ad | 1269 | #else /* !CONFIG_SMP */ |
31656519 | 1270 | static void resched_task(struct task_struct *p) |
c24d20db | 1271 | { |
05fa785c | 1272 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1273 | set_tsk_need_resched(p); |
c24d20db | 1274 | } |
e9e9250b PZ |
1275 | |
1276 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1277 | { | |
1278 | } | |
6d6bc0ad | 1279 | #endif /* CONFIG_SMP */ |
c24d20db | 1280 | |
45bf76df IM |
1281 | #if BITS_PER_LONG == 32 |
1282 | # define WMULT_CONST (~0UL) | |
1283 | #else | |
1284 | # define WMULT_CONST (1UL << 32) | |
1285 | #endif | |
1286 | ||
1287 | #define WMULT_SHIFT 32 | |
1288 | ||
194081eb IM |
1289 | /* |
1290 | * Shift right and round: | |
1291 | */ | |
cf2ab469 | 1292 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1293 | |
a7be37ac PZ |
1294 | /* |
1295 | * delta *= weight / lw | |
1296 | */ | |
cb1c4fc9 | 1297 | static unsigned long |
45bf76df IM |
1298 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1299 | struct load_weight *lw) | |
1300 | { | |
1301 | u64 tmp; | |
1302 | ||
7a232e03 LJ |
1303 | if (!lw->inv_weight) { |
1304 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1305 | lw->inv_weight = 1; | |
1306 | else | |
1307 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1308 | / (lw->weight+1); | |
1309 | } | |
45bf76df IM |
1310 | |
1311 | tmp = (u64)delta_exec * weight; | |
1312 | /* | |
1313 | * Check whether we'd overflow the 64-bit multiplication: | |
1314 | */ | |
194081eb | 1315 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1316 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1317 | WMULT_SHIFT/2); |
1318 | else | |
cf2ab469 | 1319 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1320 | |
ecf691da | 1321 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1322 | } |
1323 | ||
1091985b | 1324 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1325 | { |
1326 | lw->weight += inc; | |
e89996ae | 1327 | lw->inv_weight = 0; |
45bf76df IM |
1328 | } |
1329 | ||
1091985b | 1330 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1331 | { |
1332 | lw->weight -= dec; | |
e89996ae | 1333 | lw->inv_weight = 0; |
45bf76df IM |
1334 | } |
1335 | ||
2dd73a4f PW |
1336 | /* |
1337 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1338 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1339 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1340 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1341 | * scaled version of the new time slice allocation that they receive on time |
1342 | * slice expiry etc. | |
1343 | */ | |
1344 | ||
cce7ade8 PZ |
1345 | #define WEIGHT_IDLEPRIO 3 |
1346 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1347 | |
1348 | /* | |
1349 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1350 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1351 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1352 | * that remained on nice 0. | |
1353 | * | |
1354 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1355 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1356 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1357 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1358 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1359 | */ |
1360 | static const int prio_to_weight[40] = { | |
254753dc IM |
1361 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1362 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1363 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1364 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1365 | /* 0 */ 1024, 820, 655, 526, 423, | |
1366 | /* 5 */ 335, 272, 215, 172, 137, | |
1367 | /* 10 */ 110, 87, 70, 56, 45, | |
1368 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1369 | }; |
1370 | ||
5714d2de IM |
1371 | /* |
1372 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1373 | * | |
1374 | * In cases where the weight does not change often, we can use the | |
1375 | * precalculated inverse to speed up arithmetics by turning divisions | |
1376 | * into multiplications: | |
1377 | */ | |
dd41f596 | 1378 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1379 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1380 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1381 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1382 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1383 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1384 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1385 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1386 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1387 | }; |
2dd73a4f | 1388 | |
ef12fefa BR |
1389 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1390 | enum cpuacct_stat_index { | |
1391 | CPUACCT_STAT_USER, /* ... user mode */ | |
1392 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1393 | ||
1394 | CPUACCT_STAT_NSTATS, | |
1395 | }; | |
1396 | ||
d842de87 SV |
1397 | #ifdef CONFIG_CGROUP_CPUACCT |
1398 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1399 | static void cpuacct_update_stats(struct task_struct *tsk, |
1400 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1401 | #else |
1402 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1403 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1404 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1405 | #endif |
1406 | ||
18d95a28 PZ |
1407 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1408 | { | |
1409 | update_load_add(&rq->load, load); | |
1410 | } | |
1411 | ||
1412 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1413 | { | |
1414 | update_load_sub(&rq->load, load); | |
1415 | } | |
1416 | ||
7940ca36 | 1417 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1418 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1419 | |
1420 | /* | |
1421 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1422 | * leaving it for the final time. | |
1423 | */ | |
eb755805 | 1424 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1425 | { |
1426 | struct task_group *parent, *child; | |
eb755805 | 1427 | int ret; |
c09595f6 PZ |
1428 | |
1429 | rcu_read_lock(); | |
1430 | parent = &root_task_group; | |
1431 | down: | |
eb755805 PZ |
1432 | ret = (*down)(parent, data); |
1433 | if (ret) | |
1434 | goto out_unlock; | |
c09595f6 PZ |
1435 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1436 | parent = child; | |
1437 | goto down; | |
1438 | ||
1439 | up: | |
1440 | continue; | |
1441 | } | |
eb755805 PZ |
1442 | ret = (*up)(parent, data); |
1443 | if (ret) | |
1444 | goto out_unlock; | |
c09595f6 PZ |
1445 | |
1446 | child = parent; | |
1447 | parent = parent->parent; | |
1448 | if (parent) | |
1449 | goto up; | |
eb755805 | 1450 | out_unlock: |
c09595f6 | 1451 | rcu_read_unlock(); |
eb755805 PZ |
1452 | |
1453 | return ret; | |
c09595f6 PZ |
1454 | } |
1455 | ||
eb755805 PZ |
1456 | static int tg_nop(struct task_group *tg, void *data) |
1457 | { | |
1458 | return 0; | |
c09595f6 | 1459 | } |
eb755805 PZ |
1460 | #endif |
1461 | ||
1462 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1463 | /* Used instead of source_load when we know the type == 0 */ |
1464 | static unsigned long weighted_cpuload(const int cpu) | |
1465 | { | |
1466 | return cpu_rq(cpu)->load.weight; | |
1467 | } | |
1468 | ||
1469 | /* | |
1470 | * Return a low guess at the load of a migration-source cpu weighted | |
1471 | * according to the scheduling class and "nice" value. | |
1472 | * | |
1473 | * We want to under-estimate the load of migration sources, to | |
1474 | * balance conservatively. | |
1475 | */ | |
1476 | static unsigned long source_load(int cpu, int type) | |
1477 | { | |
1478 | struct rq *rq = cpu_rq(cpu); | |
1479 | unsigned long total = weighted_cpuload(cpu); | |
1480 | ||
1481 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1482 | return total; | |
1483 | ||
1484 | return min(rq->cpu_load[type-1], total); | |
1485 | } | |
1486 | ||
1487 | /* | |
1488 | * Return a high guess at the load of a migration-target cpu weighted | |
1489 | * according to the scheduling class and "nice" value. | |
1490 | */ | |
1491 | static unsigned long target_load(int cpu, int type) | |
1492 | { | |
1493 | struct rq *rq = cpu_rq(cpu); | |
1494 | unsigned long total = weighted_cpuload(cpu); | |
1495 | ||
1496 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1497 | return total; | |
1498 | ||
1499 | return max(rq->cpu_load[type-1], total); | |
1500 | } | |
1501 | ||
ae154be1 PZ |
1502 | static struct sched_group *group_of(int cpu) |
1503 | { | |
d11c563d | 1504 | struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd); |
ae154be1 PZ |
1505 | |
1506 | if (!sd) | |
1507 | return NULL; | |
1508 | ||
1509 | return sd->groups; | |
1510 | } | |
1511 | ||
1512 | static unsigned long power_of(int cpu) | |
1513 | { | |
1514 | struct sched_group *group = group_of(cpu); | |
1515 | ||
1516 | if (!group) | |
1517 | return SCHED_LOAD_SCALE; | |
1518 | ||
1519 | return group->cpu_power; | |
1520 | } | |
1521 | ||
eb755805 PZ |
1522 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1523 | ||
1524 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1525 | { | |
1526 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1527 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1528 | |
4cd42620 SR |
1529 | if (nr_running) |
1530 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1531 | else |
1532 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1533 | |
1534 | return rq->avg_load_per_task; | |
1535 | } | |
1536 | ||
1537 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1538 | |
43cf38eb | 1539 | static __read_mostly unsigned long __percpu *update_shares_data; |
34d76c41 | 1540 | |
c09595f6 PZ |
1541 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1542 | ||
1543 | /* | |
1544 | * Calculate and set the cpu's group shares. | |
1545 | */ | |
34d76c41 PZ |
1546 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1547 | unsigned long sd_shares, | |
1548 | unsigned long sd_rq_weight, | |
4a6cc4bd | 1549 | unsigned long *usd_rq_weight) |
18d95a28 | 1550 | { |
34d76c41 | 1551 | unsigned long shares, rq_weight; |
a5004278 | 1552 | int boost = 0; |
c09595f6 | 1553 | |
4a6cc4bd | 1554 | rq_weight = usd_rq_weight[cpu]; |
a5004278 PZ |
1555 | if (!rq_weight) { |
1556 | boost = 1; | |
1557 | rq_weight = NICE_0_LOAD; | |
1558 | } | |
c8cba857 | 1559 | |
c09595f6 | 1560 | /* |
a8af7246 PZ |
1561 | * \Sum_j shares_j * rq_weight_i |
1562 | * shares_i = ----------------------------- | |
1563 | * \Sum_j rq_weight_j | |
c09595f6 | 1564 | */ |
ec4e0e2f | 1565 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1566 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1567 | |
ffda12a1 PZ |
1568 | if (abs(shares - tg->se[cpu]->load.weight) > |
1569 | sysctl_sched_shares_thresh) { | |
1570 | struct rq *rq = cpu_rq(cpu); | |
1571 | unsigned long flags; | |
c09595f6 | 1572 | |
05fa785c | 1573 | raw_spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1574 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1575 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 | 1576 | __set_se_shares(tg->se[cpu], shares); |
05fa785c | 1577 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
ffda12a1 | 1578 | } |
18d95a28 | 1579 | } |
c09595f6 PZ |
1580 | |
1581 | /* | |
c8cba857 PZ |
1582 | * Re-compute the task group their per cpu shares over the given domain. |
1583 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1584 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1585 | */ |
eb755805 | 1586 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1587 | { |
cd8ad40d | 1588 | unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; |
4a6cc4bd | 1589 | unsigned long *usd_rq_weight; |
eb755805 | 1590 | struct sched_domain *sd = data; |
34d76c41 | 1591 | unsigned long flags; |
c8cba857 | 1592 | int i; |
c09595f6 | 1593 | |
34d76c41 PZ |
1594 | if (!tg->se[0]) |
1595 | return 0; | |
1596 | ||
1597 | local_irq_save(flags); | |
4a6cc4bd | 1598 | usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); |
34d76c41 | 1599 | |
758b2cdc | 1600 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 | 1601 | weight = tg->cfs_rq[i]->load.weight; |
4a6cc4bd | 1602 | usd_rq_weight[i] = weight; |
34d76c41 | 1603 | |
cd8ad40d | 1604 | rq_weight += weight; |
ec4e0e2f KC |
1605 | /* |
1606 | * If there are currently no tasks on the cpu pretend there | |
1607 | * is one of average load so that when a new task gets to | |
1608 | * run here it will not get delayed by group starvation. | |
1609 | */ | |
ec4e0e2f KC |
1610 | if (!weight) |
1611 | weight = NICE_0_LOAD; | |
1612 | ||
cd8ad40d | 1613 | sum_weight += weight; |
c8cba857 | 1614 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1615 | } |
c09595f6 | 1616 | |
cd8ad40d PZ |
1617 | if (!rq_weight) |
1618 | rq_weight = sum_weight; | |
1619 | ||
c8cba857 PZ |
1620 | if ((!shares && rq_weight) || shares > tg->shares) |
1621 | shares = tg->shares; | |
1622 | ||
1623 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1624 | shares = tg->shares; | |
c09595f6 | 1625 | |
758b2cdc | 1626 | for_each_cpu(i, sched_domain_span(sd)) |
4a6cc4bd | 1627 | update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); |
34d76c41 PZ |
1628 | |
1629 | local_irq_restore(flags); | |
eb755805 PZ |
1630 | |
1631 | return 0; | |
c09595f6 PZ |
1632 | } |
1633 | ||
1634 | /* | |
c8cba857 PZ |
1635 | * Compute the cpu's hierarchical load factor for each task group. |
1636 | * This needs to be done in a top-down fashion because the load of a child | |
1637 | * group is a fraction of its parents load. | |
c09595f6 | 1638 | */ |
eb755805 | 1639 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1640 | { |
c8cba857 | 1641 | unsigned long load; |
eb755805 | 1642 | long cpu = (long)data; |
c09595f6 | 1643 | |
c8cba857 PZ |
1644 | if (!tg->parent) { |
1645 | load = cpu_rq(cpu)->load.weight; | |
1646 | } else { | |
1647 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1648 | load *= tg->cfs_rq[cpu]->shares; | |
1649 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1650 | } | |
c09595f6 | 1651 | |
c8cba857 | 1652 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1653 | |
eb755805 | 1654 | return 0; |
c09595f6 PZ |
1655 | } |
1656 | ||
c8cba857 | 1657 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1658 | { |
e7097159 PZ |
1659 | s64 elapsed; |
1660 | u64 now; | |
1661 | ||
1662 | if (root_task_group_empty()) | |
1663 | return; | |
1664 | ||
1665 | now = cpu_clock(raw_smp_processor_id()); | |
1666 | elapsed = now - sd->last_update; | |
2398f2c6 PZ |
1667 | |
1668 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1669 | sd->last_update = now; | |
eb755805 | 1670 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1671 | } |
4d8d595d PZ |
1672 | } |
1673 | ||
eb755805 | 1674 | static void update_h_load(long cpu) |
c09595f6 | 1675 | { |
e7097159 PZ |
1676 | if (root_task_group_empty()) |
1677 | return; | |
1678 | ||
eb755805 | 1679 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1680 | } |
1681 | ||
c09595f6 PZ |
1682 | #else |
1683 | ||
c8cba857 | 1684 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1685 | { |
1686 | } | |
1687 | ||
18d95a28 PZ |
1688 | #endif |
1689 | ||
8f45e2b5 GH |
1690 | #ifdef CONFIG_PREEMPT |
1691 | ||
b78bb868 PZ |
1692 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1693 | ||
70574a99 | 1694 | /* |
8f45e2b5 GH |
1695 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1696 | * way at the expense of forcing extra atomic operations in all | |
1697 | * invocations. This assures that the double_lock is acquired using the | |
1698 | * same underlying policy as the spinlock_t on this architecture, which | |
1699 | * reduces latency compared to the unfair variant below. However, it | |
1700 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1701 | */ |
8f45e2b5 GH |
1702 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1703 | __releases(this_rq->lock) | |
1704 | __acquires(busiest->lock) | |
1705 | __acquires(this_rq->lock) | |
1706 | { | |
05fa785c | 1707 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1708 | double_rq_lock(this_rq, busiest); |
1709 | ||
1710 | return 1; | |
1711 | } | |
1712 | ||
1713 | #else | |
1714 | /* | |
1715 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1716 | * latency by eliminating extra atomic operations when the locks are | |
1717 | * already in proper order on entry. This favors lower cpu-ids and will | |
1718 | * grant the double lock to lower cpus over higher ids under contention, | |
1719 | * regardless of entry order into the function. | |
1720 | */ | |
1721 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1722 | __releases(this_rq->lock) |
1723 | __acquires(busiest->lock) | |
1724 | __acquires(this_rq->lock) | |
1725 | { | |
1726 | int ret = 0; | |
1727 | ||
05fa785c | 1728 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1729 | if (busiest < this_rq) { |
05fa785c TG |
1730 | raw_spin_unlock(&this_rq->lock); |
1731 | raw_spin_lock(&busiest->lock); | |
1732 | raw_spin_lock_nested(&this_rq->lock, | |
1733 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1734 | ret = 1; |
1735 | } else | |
05fa785c TG |
1736 | raw_spin_lock_nested(&busiest->lock, |
1737 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1738 | } |
1739 | return ret; | |
1740 | } | |
1741 | ||
8f45e2b5 GH |
1742 | #endif /* CONFIG_PREEMPT */ |
1743 | ||
1744 | /* | |
1745 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1746 | */ | |
1747 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1748 | { | |
1749 | if (unlikely(!irqs_disabled())) { | |
1750 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1751 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1752 | BUG_ON(1); |
1753 | } | |
1754 | ||
1755 | return _double_lock_balance(this_rq, busiest); | |
1756 | } | |
1757 | ||
70574a99 AD |
1758 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1759 | __releases(busiest->lock) | |
1760 | { | |
05fa785c | 1761 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1762 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1763 | } | |
1e3c88bd PZ |
1764 | |
1765 | /* | |
1766 | * double_rq_lock - safely lock two runqueues | |
1767 | * | |
1768 | * Note this does not disable interrupts like task_rq_lock, | |
1769 | * you need to do so manually before calling. | |
1770 | */ | |
1771 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1772 | __acquires(rq1->lock) | |
1773 | __acquires(rq2->lock) | |
1774 | { | |
1775 | BUG_ON(!irqs_disabled()); | |
1776 | if (rq1 == rq2) { | |
1777 | raw_spin_lock(&rq1->lock); | |
1778 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1779 | } else { | |
1780 | if (rq1 < rq2) { | |
1781 | raw_spin_lock(&rq1->lock); | |
1782 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1783 | } else { | |
1784 | raw_spin_lock(&rq2->lock); | |
1785 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1786 | } | |
1787 | } | |
1e3c88bd PZ |
1788 | } |
1789 | ||
1790 | /* | |
1791 | * double_rq_unlock - safely unlock two runqueues | |
1792 | * | |
1793 | * Note this does not restore interrupts like task_rq_unlock, | |
1794 | * you need to do so manually after calling. | |
1795 | */ | |
1796 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1797 | __releases(rq1->lock) | |
1798 | __releases(rq2->lock) | |
1799 | { | |
1800 | raw_spin_unlock(&rq1->lock); | |
1801 | if (rq1 != rq2) | |
1802 | raw_spin_unlock(&rq2->lock); | |
1803 | else | |
1804 | __release(rq2->lock); | |
1805 | } | |
1806 | ||
18d95a28 PZ |
1807 | #endif |
1808 | ||
30432094 | 1809 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1810 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1811 | { | |
30432094 | 1812 | #ifdef CONFIG_SMP |
34e83e85 IM |
1813 | cfs_rq->shares = shares; |
1814 | #endif | |
1815 | } | |
30432094 | 1816 | #endif |
e7693a36 | 1817 | |
74f5187a | 1818 | static void calc_load_account_idle(struct rq *this_rq); |
0bcdcf28 | 1819 | static void update_sysctl(void); |
acb4a848 | 1820 | static int get_update_sysctl_factor(void); |
dce48a84 | 1821 | |
cd29fe6f PZ |
1822 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1823 | { | |
1824 | set_task_rq(p, cpu); | |
1825 | #ifdef CONFIG_SMP | |
1826 | /* | |
1827 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1828 | * successfuly executed on another CPU. We must ensure that updates of | |
1829 | * per-task data have been completed by this moment. | |
1830 | */ | |
1831 | smp_wmb(); | |
1832 | task_thread_info(p)->cpu = cpu; | |
1833 | #endif | |
1834 | } | |
dce48a84 | 1835 | |
1e3c88bd | 1836 | static const struct sched_class rt_sched_class; |
dd41f596 IM |
1837 | |
1838 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1839 | #define for_each_class(class) \ |
1840 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1841 | |
1e3c88bd PZ |
1842 | #include "sched_stats.h" |
1843 | ||
c09595f6 | 1844 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1845 | { |
1846 | rq->nr_running++; | |
9c217245 IM |
1847 | } |
1848 | ||
c09595f6 | 1849 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1850 | { |
1851 | rq->nr_running--; | |
9c217245 IM |
1852 | } |
1853 | ||
45bf76df IM |
1854 | static void set_load_weight(struct task_struct *p) |
1855 | { | |
1856 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1857 | p->se.load.weight = prio_to_weight[0] * 2; |
1858 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1859 | return; | |
1860 | } | |
45bf76df | 1861 | |
dd41f596 IM |
1862 | /* |
1863 | * SCHED_IDLE tasks get minimal weight: | |
1864 | */ | |
1865 | if (p->policy == SCHED_IDLE) { | |
1866 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1867 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1868 | return; | |
1869 | } | |
71f8bd46 | 1870 | |
dd41f596 IM |
1871 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1872 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1873 | } |
1874 | ||
371fd7e7 | 1875 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 1876 | { |
a64692a3 | 1877 | update_rq_clock(rq); |
dd41f596 | 1878 | sched_info_queued(p); |
371fd7e7 | 1879 | p->sched_class->enqueue_task(rq, p, flags); |
dd41f596 | 1880 | p->se.on_rq = 1; |
71f8bd46 IM |
1881 | } |
1882 | ||
371fd7e7 | 1883 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 1884 | { |
a64692a3 | 1885 | update_rq_clock(rq); |
46ac22ba | 1886 | sched_info_dequeued(p); |
371fd7e7 | 1887 | p->sched_class->dequeue_task(rq, p, flags); |
dd41f596 | 1888 | p->se.on_rq = 0; |
71f8bd46 IM |
1889 | } |
1890 | ||
1e3c88bd PZ |
1891 | /* |
1892 | * activate_task - move a task to the runqueue. | |
1893 | */ | |
371fd7e7 | 1894 | static void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1895 | { |
1896 | if (task_contributes_to_load(p)) | |
1897 | rq->nr_uninterruptible--; | |
1898 | ||
371fd7e7 | 1899 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
1900 | inc_nr_running(rq); |
1901 | } | |
1902 | ||
1903 | /* | |
1904 | * deactivate_task - remove a task from the runqueue. | |
1905 | */ | |
371fd7e7 | 1906 | static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1907 | { |
1908 | if (task_contributes_to_load(p)) | |
1909 | rq->nr_uninterruptible++; | |
1910 | ||
371fd7e7 | 1911 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
1912 | dec_nr_running(rq); |
1913 | } | |
1914 | ||
1915 | #include "sched_idletask.c" | |
1916 | #include "sched_fair.c" | |
1917 | #include "sched_rt.c" | |
1918 | #ifdef CONFIG_SCHED_DEBUG | |
1919 | # include "sched_debug.c" | |
1920 | #endif | |
1921 | ||
14531189 | 1922 | /* |
dd41f596 | 1923 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1924 | */ |
14531189 IM |
1925 | static inline int __normal_prio(struct task_struct *p) |
1926 | { | |
dd41f596 | 1927 | return p->static_prio; |
14531189 IM |
1928 | } |
1929 | ||
b29739f9 IM |
1930 | /* |
1931 | * Calculate the expected normal priority: i.e. priority | |
1932 | * without taking RT-inheritance into account. Might be | |
1933 | * boosted by interactivity modifiers. Changes upon fork, | |
1934 | * setprio syscalls, and whenever the interactivity | |
1935 | * estimator recalculates. | |
1936 | */ | |
36c8b586 | 1937 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1938 | { |
1939 | int prio; | |
1940 | ||
e05606d3 | 1941 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1942 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1943 | else | |
1944 | prio = __normal_prio(p); | |
1945 | return prio; | |
1946 | } | |
1947 | ||
1948 | /* | |
1949 | * Calculate the current priority, i.e. the priority | |
1950 | * taken into account by the scheduler. This value might | |
1951 | * be boosted by RT tasks, or might be boosted by | |
1952 | * interactivity modifiers. Will be RT if the task got | |
1953 | * RT-boosted. If not then it returns p->normal_prio. | |
1954 | */ | |
36c8b586 | 1955 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1956 | { |
1957 | p->normal_prio = normal_prio(p); | |
1958 | /* | |
1959 | * If we are RT tasks or we were boosted to RT priority, | |
1960 | * keep the priority unchanged. Otherwise, update priority | |
1961 | * to the normal priority: | |
1962 | */ | |
1963 | if (!rt_prio(p->prio)) | |
1964 | return p->normal_prio; | |
1965 | return p->prio; | |
1966 | } | |
1967 | ||
1da177e4 LT |
1968 | /** |
1969 | * task_curr - is this task currently executing on a CPU? | |
1970 | * @p: the task in question. | |
1971 | */ | |
36c8b586 | 1972 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1973 | { |
1974 | return cpu_curr(task_cpu(p)) == p; | |
1975 | } | |
1976 | ||
cb469845 SR |
1977 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1978 | const struct sched_class *prev_class, | |
1979 | int oldprio, int running) | |
1980 | { | |
1981 | if (prev_class != p->sched_class) { | |
1982 | if (prev_class->switched_from) | |
1983 | prev_class->switched_from(rq, p, running); | |
1984 | p->sched_class->switched_to(rq, p, running); | |
1985 | } else | |
1986 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1987 | } | |
1988 | ||
1da177e4 | 1989 | #ifdef CONFIG_SMP |
cc367732 IM |
1990 | /* |
1991 | * Is this task likely cache-hot: | |
1992 | */ | |
e7693a36 | 1993 | static int |
cc367732 IM |
1994 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
1995 | { | |
1996 | s64 delta; | |
1997 | ||
e6c8fba7 PZ |
1998 | if (p->sched_class != &fair_sched_class) |
1999 | return 0; | |
2000 | ||
f540a608 IM |
2001 | /* |
2002 | * Buddy candidates are cache hot: | |
2003 | */ | |
f685ceac | 2004 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2005 | (&p->se == cfs_rq_of(&p->se)->next || |
2006 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2007 | return 1; |
2008 | ||
6bc1665b IM |
2009 | if (sysctl_sched_migration_cost == -1) |
2010 | return 1; | |
2011 | if (sysctl_sched_migration_cost == 0) | |
2012 | return 0; | |
2013 | ||
cc367732 IM |
2014 | delta = now - p->se.exec_start; |
2015 | ||
2016 | return delta < (s64)sysctl_sched_migration_cost; | |
2017 | } | |
2018 | ||
dd41f596 | 2019 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2020 | { |
e2912009 PZ |
2021 | #ifdef CONFIG_SCHED_DEBUG |
2022 | /* | |
2023 | * We should never call set_task_cpu() on a blocked task, | |
2024 | * ttwu() will sort out the placement. | |
2025 | */ | |
077614ee PZ |
2026 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2027 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
e2912009 PZ |
2028 | #endif |
2029 | ||
de1d7286 | 2030 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2031 | |
0c69774e PZ |
2032 | if (task_cpu(p) != new_cpu) { |
2033 | p->se.nr_migrations++; | |
2034 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); | |
2035 | } | |
dd41f596 IM |
2036 | |
2037 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2038 | } |
2039 | ||
969c7921 | 2040 | struct migration_arg { |
36c8b586 | 2041 | struct task_struct *task; |
1da177e4 | 2042 | int dest_cpu; |
70b97a7f | 2043 | }; |
1da177e4 | 2044 | |
969c7921 TH |
2045 | static int migration_cpu_stop(void *data); |
2046 | ||
1da177e4 LT |
2047 | /* |
2048 | * The task's runqueue lock must be held. | |
2049 | * Returns true if you have to wait for migration thread. | |
2050 | */ | |
969c7921 | 2051 | static bool migrate_task(struct task_struct *p, int dest_cpu) |
1da177e4 | 2052 | { |
70b97a7f | 2053 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2054 | |
2055 | /* | |
2056 | * If the task is not on a runqueue (and not running), then | |
e2912009 | 2057 | * the next wake-up will properly place the task. |
1da177e4 | 2058 | */ |
969c7921 | 2059 | return p->se.on_rq || task_running(rq, p); |
1da177e4 LT |
2060 | } |
2061 | ||
2062 | /* | |
2063 | * wait_task_inactive - wait for a thread to unschedule. | |
2064 | * | |
85ba2d86 RM |
2065 | * If @match_state is nonzero, it's the @p->state value just checked and |
2066 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2067 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2068 | * we return a positive number (its total switch count). If a second call | |
2069 | * a short while later returns the same number, the caller can be sure that | |
2070 | * @p has remained unscheduled the whole time. | |
2071 | * | |
1da177e4 LT |
2072 | * The caller must ensure that the task *will* unschedule sometime soon, |
2073 | * else this function might spin for a *long* time. This function can't | |
2074 | * be called with interrupts off, or it may introduce deadlock with | |
2075 | * smp_call_function() if an IPI is sent by the same process we are | |
2076 | * waiting to become inactive. | |
2077 | */ | |
85ba2d86 | 2078 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2079 | { |
2080 | unsigned long flags; | |
dd41f596 | 2081 | int running, on_rq; |
85ba2d86 | 2082 | unsigned long ncsw; |
70b97a7f | 2083 | struct rq *rq; |
1da177e4 | 2084 | |
3a5c359a AK |
2085 | for (;;) { |
2086 | /* | |
2087 | * We do the initial early heuristics without holding | |
2088 | * any task-queue locks at all. We'll only try to get | |
2089 | * the runqueue lock when things look like they will | |
2090 | * work out! | |
2091 | */ | |
2092 | rq = task_rq(p); | |
fa490cfd | 2093 | |
3a5c359a AK |
2094 | /* |
2095 | * If the task is actively running on another CPU | |
2096 | * still, just relax and busy-wait without holding | |
2097 | * any locks. | |
2098 | * | |
2099 | * NOTE! Since we don't hold any locks, it's not | |
2100 | * even sure that "rq" stays as the right runqueue! | |
2101 | * But we don't care, since "task_running()" will | |
2102 | * return false if the runqueue has changed and p | |
2103 | * is actually now running somewhere else! | |
2104 | */ | |
85ba2d86 RM |
2105 | while (task_running(rq, p)) { |
2106 | if (match_state && unlikely(p->state != match_state)) | |
2107 | return 0; | |
3a5c359a | 2108 | cpu_relax(); |
85ba2d86 | 2109 | } |
fa490cfd | 2110 | |
3a5c359a AK |
2111 | /* |
2112 | * Ok, time to look more closely! We need the rq | |
2113 | * lock now, to be *sure*. If we're wrong, we'll | |
2114 | * just go back and repeat. | |
2115 | */ | |
2116 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 2117 | trace_sched_wait_task(p); |
3a5c359a AK |
2118 | running = task_running(rq, p); |
2119 | on_rq = p->se.on_rq; | |
85ba2d86 | 2120 | ncsw = 0; |
f31e11d8 | 2121 | if (!match_state || p->state == match_state) |
93dcf55f | 2122 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2123 | task_rq_unlock(rq, &flags); |
fa490cfd | 2124 | |
85ba2d86 RM |
2125 | /* |
2126 | * If it changed from the expected state, bail out now. | |
2127 | */ | |
2128 | if (unlikely(!ncsw)) | |
2129 | break; | |
2130 | ||
3a5c359a AK |
2131 | /* |
2132 | * Was it really running after all now that we | |
2133 | * checked with the proper locks actually held? | |
2134 | * | |
2135 | * Oops. Go back and try again.. | |
2136 | */ | |
2137 | if (unlikely(running)) { | |
2138 | cpu_relax(); | |
2139 | continue; | |
2140 | } | |
fa490cfd | 2141 | |
3a5c359a AK |
2142 | /* |
2143 | * It's not enough that it's not actively running, | |
2144 | * it must be off the runqueue _entirely_, and not | |
2145 | * preempted! | |
2146 | * | |
80dd99b3 | 2147 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2148 | * running right now), it's preempted, and we should |
2149 | * yield - it could be a while. | |
2150 | */ | |
2151 | if (unlikely(on_rq)) { | |
2152 | schedule_timeout_uninterruptible(1); | |
2153 | continue; | |
2154 | } | |
fa490cfd | 2155 | |
3a5c359a AK |
2156 | /* |
2157 | * Ahh, all good. It wasn't running, and it wasn't | |
2158 | * runnable, which means that it will never become | |
2159 | * running in the future either. We're all done! | |
2160 | */ | |
2161 | break; | |
2162 | } | |
85ba2d86 RM |
2163 | |
2164 | return ncsw; | |
1da177e4 LT |
2165 | } |
2166 | ||
2167 | /*** | |
2168 | * kick_process - kick a running thread to enter/exit the kernel | |
2169 | * @p: the to-be-kicked thread | |
2170 | * | |
2171 | * Cause a process which is running on another CPU to enter | |
2172 | * kernel-mode, without any delay. (to get signals handled.) | |
2173 | * | |
2174 | * NOTE: this function doesnt have to take the runqueue lock, | |
2175 | * because all it wants to ensure is that the remote task enters | |
2176 | * the kernel. If the IPI races and the task has been migrated | |
2177 | * to another CPU then no harm is done and the purpose has been | |
2178 | * achieved as well. | |
2179 | */ | |
36c8b586 | 2180 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2181 | { |
2182 | int cpu; | |
2183 | ||
2184 | preempt_disable(); | |
2185 | cpu = task_cpu(p); | |
2186 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2187 | smp_send_reschedule(cpu); | |
2188 | preempt_enable(); | |
2189 | } | |
b43e3521 | 2190 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2191 | #endif /* CONFIG_SMP */ |
1da177e4 | 2192 | |
0793a61d TG |
2193 | /** |
2194 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2195 | * @p: the task to evaluate | |
2196 | * @func: the function to be called | |
2197 | * @info: the function call argument | |
2198 | * | |
2199 | * Calls the function @func when the task is currently running. This might | |
2200 | * be on the current CPU, which just calls the function directly | |
2201 | */ | |
2202 | void task_oncpu_function_call(struct task_struct *p, | |
2203 | void (*func) (void *info), void *info) | |
2204 | { | |
2205 | int cpu; | |
2206 | ||
2207 | preempt_disable(); | |
2208 | cpu = task_cpu(p); | |
2209 | if (task_curr(p)) | |
2210 | smp_call_function_single(cpu, func, info, 1); | |
2211 | preempt_enable(); | |
2212 | } | |
2213 | ||
970b13ba | 2214 | #ifdef CONFIG_SMP |
30da688e ON |
2215 | /* |
2216 | * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held. | |
2217 | */ | |
5da9a0fb PZ |
2218 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2219 | { | |
2220 | int dest_cpu; | |
2221 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2222 | ||
2223 | /* Look for allowed, online CPU in same node. */ | |
2224 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2225 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2226 | return dest_cpu; | |
2227 | ||
2228 | /* Any allowed, online CPU? */ | |
2229 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2230 | if (dest_cpu < nr_cpu_ids) | |
2231 | return dest_cpu; | |
2232 | ||
2233 | /* No more Mr. Nice Guy. */ | |
897f0b3c | 2234 | if (unlikely(dest_cpu >= nr_cpu_ids)) { |
9084bb82 | 2235 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
5da9a0fb PZ |
2236 | /* |
2237 | * Don't tell them about moving exiting tasks or | |
2238 | * kernel threads (both mm NULL), since they never | |
2239 | * leave kernel. | |
2240 | */ | |
2241 | if (p->mm && printk_ratelimit()) { | |
2242 | printk(KERN_INFO "process %d (%s) no " | |
2243 | "longer affine to cpu%d\n", | |
2244 | task_pid_nr(p), p->comm, cpu); | |
2245 | } | |
2246 | } | |
2247 | ||
2248 | return dest_cpu; | |
2249 | } | |
2250 | ||
e2912009 | 2251 | /* |
30da688e | 2252 | * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable. |
e2912009 | 2253 | */ |
970b13ba | 2254 | static inline |
0017d735 | 2255 | int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 2256 | { |
0017d735 | 2257 | int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags); |
e2912009 PZ |
2258 | |
2259 | /* | |
2260 | * In order not to call set_task_cpu() on a blocking task we need | |
2261 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2262 | * cpu. | |
2263 | * | |
2264 | * Since this is common to all placement strategies, this lives here. | |
2265 | * | |
2266 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2267 | * not worry about this generic constraint ] | |
2268 | */ | |
2269 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2270 | !cpu_online(cpu))) |
5da9a0fb | 2271 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2272 | |
2273 | return cpu; | |
970b13ba | 2274 | } |
09a40af5 MG |
2275 | |
2276 | static void update_avg(u64 *avg, u64 sample) | |
2277 | { | |
2278 | s64 diff = sample - *avg; | |
2279 | *avg += diff >> 3; | |
2280 | } | |
970b13ba PZ |
2281 | #endif |
2282 | ||
1da177e4 LT |
2283 | /*** |
2284 | * try_to_wake_up - wake up a thread | |
2285 | * @p: the to-be-woken-up thread | |
2286 | * @state: the mask of task states that can be woken | |
2287 | * @sync: do a synchronous wakeup? | |
2288 | * | |
2289 | * Put it on the run-queue if it's not already there. The "current" | |
2290 | * thread is always on the run-queue (except when the actual | |
2291 | * re-schedule is in progress), and as such you're allowed to do | |
2292 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2293 | * runnable without the overhead of this. | |
2294 | * | |
2295 | * returns failure only if the task is already active. | |
2296 | */ | |
7d478721 PZ |
2297 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2298 | int wake_flags) | |
1da177e4 | 2299 | { |
cc367732 | 2300 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 | 2301 | unsigned long flags; |
371fd7e7 | 2302 | unsigned long en_flags = ENQUEUE_WAKEUP; |
ab3b3aa5 | 2303 | struct rq *rq; |
1da177e4 | 2304 | |
e9c84311 | 2305 | this_cpu = get_cpu(); |
2398f2c6 | 2306 | |
04e2f174 | 2307 | smp_wmb(); |
ab3b3aa5 | 2308 | rq = task_rq_lock(p, &flags); |
e9c84311 | 2309 | if (!(p->state & state)) |
1da177e4 LT |
2310 | goto out; |
2311 | ||
dd41f596 | 2312 | if (p->se.on_rq) |
1da177e4 LT |
2313 | goto out_running; |
2314 | ||
2315 | cpu = task_cpu(p); | |
cc367732 | 2316 | orig_cpu = cpu; |
1da177e4 LT |
2317 | |
2318 | #ifdef CONFIG_SMP | |
2319 | if (unlikely(task_running(rq, p))) | |
2320 | goto out_activate; | |
2321 | ||
e9c84311 PZ |
2322 | /* |
2323 | * In order to handle concurrent wakeups and release the rq->lock | |
2324 | * we put the task in TASK_WAKING state. | |
eb24073b IM |
2325 | * |
2326 | * First fix up the nr_uninterruptible count: | |
e9c84311 | 2327 | */ |
cc87f76a PZ |
2328 | if (task_contributes_to_load(p)) { |
2329 | if (likely(cpu_online(orig_cpu))) | |
2330 | rq->nr_uninterruptible--; | |
2331 | else | |
2332 | this_rq()->nr_uninterruptible--; | |
2333 | } | |
e9c84311 | 2334 | p->state = TASK_WAKING; |
efbbd05a | 2335 | |
371fd7e7 | 2336 | if (p->sched_class->task_waking) { |
efbbd05a | 2337 | p->sched_class->task_waking(rq, p); |
371fd7e7 PZ |
2338 | en_flags |= ENQUEUE_WAKING; |
2339 | } | |
efbbd05a | 2340 | |
0017d735 PZ |
2341 | cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); |
2342 | if (cpu != orig_cpu) | |
5d2f5a61 | 2343 | set_task_cpu(p, cpu); |
0017d735 | 2344 | __task_rq_unlock(rq); |
ab19cb23 | 2345 | |
0970d299 PZ |
2346 | rq = cpu_rq(cpu); |
2347 | raw_spin_lock(&rq->lock); | |
f5dc3753 | 2348 | |
0970d299 PZ |
2349 | /* |
2350 | * We migrated the task without holding either rq->lock, however | |
2351 | * since the task is not on the task list itself, nobody else | |
2352 | * will try and migrate the task, hence the rq should match the | |
2353 | * cpu we just moved it to. | |
2354 | */ | |
2355 | WARN_ON(task_cpu(p) != cpu); | |
e9c84311 | 2356 | WARN_ON(p->state != TASK_WAKING); |
1da177e4 | 2357 | |
e7693a36 GH |
2358 | #ifdef CONFIG_SCHEDSTATS |
2359 | schedstat_inc(rq, ttwu_count); | |
2360 | if (cpu == this_cpu) | |
2361 | schedstat_inc(rq, ttwu_local); | |
2362 | else { | |
2363 | struct sched_domain *sd; | |
2364 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2365 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2366 | schedstat_inc(sd, ttwu_wake_remote); |
2367 | break; | |
2368 | } | |
2369 | } | |
2370 | } | |
6d6bc0ad | 2371 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2372 | |
1da177e4 LT |
2373 | out_activate: |
2374 | #endif /* CONFIG_SMP */ | |
41acab88 | 2375 | schedstat_inc(p, se.statistics.nr_wakeups); |
7d478721 | 2376 | if (wake_flags & WF_SYNC) |
41acab88 | 2377 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
cc367732 | 2378 | if (orig_cpu != cpu) |
41acab88 | 2379 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); |
cc367732 | 2380 | if (cpu == this_cpu) |
41acab88 | 2381 | schedstat_inc(p, se.statistics.nr_wakeups_local); |
cc367732 | 2382 | else |
41acab88 | 2383 | schedstat_inc(p, se.statistics.nr_wakeups_remote); |
371fd7e7 | 2384 | activate_task(rq, p, en_flags); |
1da177e4 LT |
2385 | success = 1; |
2386 | ||
2387 | out_running: | |
27a9da65 | 2388 | trace_sched_wakeup(p, success); |
7d478721 | 2389 | check_preempt_curr(rq, p, wake_flags); |
4ae7d5ce | 2390 | |
1da177e4 | 2391 | p->state = TASK_RUNNING; |
9a897c5a | 2392 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2393 | if (p->sched_class->task_woken) |
2394 | p->sched_class->task_woken(rq, p); | |
eae0c9df MG |
2395 | |
2396 | if (unlikely(rq->idle_stamp)) { | |
2397 | u64 delta = rq->clock - rq->idle_stamp; | |
2398 | u64 max = 2*sysctl_sched_migration_cost; | |
2399 | ||
2400 | if (delta > max) | |
2401 | rq->avg_idle = max; | |
2402 | else | |
2403 | update_avg(&rq->avg_idle, delta); | |
2404 | rq->idle_stamp = 0; | |
2405 | } | |
9a897c5a | 2406 | #endif |
1da177e4 LT |
2407 | out: |
2408 | task_rq_unlock(rq, &flags); | |
e9c84311 | 2409 | put_cpu(); |
1da177e4 LT |
2410 | |
2411 | return success; | |
2412 | } | |
2413 | ||
50fa610a DH |
2414 | /** |
2415 | * wake_up_process - Wake up a specific process | |
2416 | * @p: The process to be woken up. | |
2417 | * | |
2418 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2419 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2420 | * running. | |
2421 | * | |
2422 | * It may be assumed that this function implies a write memory barrier before | |
2423 | * changing the task state if and only if any tasks are woken up. | |
2424 | */ | |
7ad5b3a5 | 2425 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2426 | { |
d9514f6c | 2427 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2428 | } |
1da177e4 LT |
2429 | EXPORT_SYMBOL(wake_up_process); |
2430 | ||
7ad5b3a5 | 2431 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2432 | { |
2433 | return try_to_wake_up(p, state, 0); | |
2434 | } | |
2435 | ||
1da177e4 LT |
2436 | /* |
2437 | * Perform scheduler related setup for a newly forked process p. | |
2438 | * p is forked by current. | |
dd41f596 IM |
2439 | * |
2440 | * __sched_fork() is basic setup used by init_idle() too: | |
2441 | */ | |
2442 | static void __sched_fork(struct task_struct *p) | |
2443 | { | |
dd41f596 IM |
2444 | p->se.exec_start = 0; |
2445 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2446 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2447 | p->se.nr_migrations = 0; |
6cfb0d5d IM |
2448 | |
2449 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 2450 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 2451 | #endif |
476d139c | 2452 | |
fa717060 | 2453 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2454 | p->se.on_rq = 0; |
4a55bd5e | 2455 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2456 | |
e107be36 AK |
2457 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2458 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2459 | #endif | |
dd41f596 IM |
2460 | } |
2461 | ||
2462 | /* | |
2463 | * fork()/clone()-time setup: | |
2464 | */ | |
2465 | void sched_fork(struct task_struct *p, int clone_flags) | |
2466 | { | |
2467 | int cpu = get_cpu(); | |
2468 | ||
2469 | __sched_fork(p); | |
06b83b5f | 2470 | /* |
0017d735 | 2471 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
2472 | * nobody will actually run it, and a signal or other external |
2473 | * event cannot wake it up and insert it on the runqueue either. | |
2474 | */ | |
0017d735 | 2475 | p->state = TASK_RUNNING; |
dd41f596 | 2476 | |
b9dc29e7 MG |
2477 | /* |
2478 | * Revert to default priority/policy on fork if requested. | |
2479 | */ | |
2480 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2481 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2482 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2483 | p->normal_prio = p->static_prio; |
2484 | } | |
b9dc29e7 | 2485 | |
6c697bdf MG |
2486 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2487 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2488 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2489 | set_load_weight(p); |
2490 | } | |
2491 | ||
b9dc29e7 MG |
2492 | /* |
2493 | * We don't need the reset flag anymore after the fork. It has | |
2494 | * fulfilled its duty: | |
2495 | */ | |
2496 | p->sched_reset_on_fork = 0; | |
2497 | } | |
ca94c442 | 2498 | |
f83f9ac2 PW |
2499 | /* |
2500 | * Make sure we do not leak PI boosting priority to the child. | |
2501 | */ | |
2502 | p->prio = current->normal_prio; | |
2503 | ||
2ddbf952 HS |
2504 | if (!rt_prio(p->prio)) |
2505 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2506 | |
cd29fe6f PZ |
2507 | if (p->sched_class->task_fork) |
2508 | p->sched_class->task_fork(p); | |
2509 | ||
5f3edc1b PZ |
2510 | set_task_cpu(p, cpu); |
2511 | ||
52f17b6c | 2512 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2513 | if (likely(sched_info_on())) |
52f17b6c | 2514 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2515 | #endif |
d6077cb8 | 2516 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2517 | p->oncpu = 0; |
2518 | #endif | |
1da177e4 | 2519 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2520 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2521 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2522 | #endif |
917b627d GH |
2523 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
2524 | ||
476d139c | 2525 | put_cpu(); |
1da177e4 LT |
2526 | } |
2527 | ||
2528 | /* | |
2529 | * wake_up_new_task - wake up a newly created task for the first time. | |
2530 | * | |
2531 | * This function will do some initial scheduler statistics housekeeping | |
2532 | * that must be done for every newly created context, then puts the task | |
2533 | * on the runqueue and wakes it. | |
2534 | */ | |
7ad5b3a5 | 2535 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2536 | { |
2537 | unsigned long flags; | |
dd41f596 | 2538 | struct rq *rq; |
c890692b | 2539 | int cpu __maybe_unused = get_cpu(); |
fabf318e PZ |
2540 | |
2541 | #ifdef CONFIG_SMP | |
0017d735 PZ |
2542 | rq = task_rq_lock(p, &flags); |
2543 | p->state = TASK_WAKING; | |
2544 | ||
fabf318e PZ |
2545 | /* |
2546 | * Fork balancing, do it here and not earlier because: | |
2547 | * - cpus_allowed can change in the fork path | |
2548 | * - any previously selected cpu might disappear through hotplug | |
2549 | * | |
0017d735 PZ |
2550 | * We set TASK_WAKING so that select_task_rq() can drop rq->lock |
2551 | * without people poking at ->cpus_allowed. | |
fabf318e | 2552 | */ |
0017d735 | 2553 | cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0); |
fabf318e | 2554 | set_task_cpu(p, cpu); |
1da177e4 | 2555 | |
06b83b5f | 2556 | p->state = TASK_RUNNING; |
0017d735 PZ |
2557 | task_rq_unlock(rq, &flags); |
2558 | #endif | |
2559 | ||
2560 | rq = task_rq_lock(p, &flags); | |
cd29fe6f | 2561 | activate_task(rq, p, 0); |
27a9da65 | 2562 | trace_sched_wakeup_new(p, 1); |
a7558e01 | 2563 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2564 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2565 | if (p->sched_class->task_woken) |
2566 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2567 | #endif |
dd41f596 | 2568 | task_rq_unlock(rq, &flags); |
fabf318e | 2569 | put_cpu(); |
1da177e4 LT |
2570 | } |
2571 | ||
e107be36 AK |
2572 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2573 | ||
2574 | /** | |
80dd99b3 | 2575 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2576 | * @notifier: notifier struct to register |
e107be36 AK |
2577 | */ |
2578 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2579 | { | |
2580 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2581 | } | |
2582 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2583 | ||
2584 | /** | |
2585 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2586 | * @notifier: notifier struct to unregister |
e107be36 AK |
2587 | * |
2588 | * This is safe to call from within a preemption notifier. | |
2589 | */ | |
2590 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2591 | { | |
2592 | hlist_del(¬ifier->link); | |
2593 | } | |
2594 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2595 | ||
2596 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2597 | { | |
2598 | struct preempt_notifier *notifier; | |
2599 | struct hlist_node *node; | |
2600 | ||
2601 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2602 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2603 | } | |
2604 | ||
2605 | static void | |
2606 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2607 | struct task_struct *next) | |
2608 | { | |
2609 | struct preempt_notifier *notifier; | |
2610 | struct hlist_node *node; | |
2611 | ||
2612 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2613 | notifier->ops->sched_out(notifier, next); | |
2614 | } | |
2615 | ||
6d6bc0ad | 2616 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2617 | |
2618 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2619 | { | |
2620 | } | |
2621 | ||
2622 | static void | |
2623 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2624 | struct task_struct *next) | |
2625 | { | |
2626 | } | |
2627 | ||
6d6bc0ad | 2628 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2629 | |
4866cde0 NP |
2630 | /** |
2631 | * prepare_task_switch - prepare to switch tasks | |
2632 | * @rq: the runqueue preparing to switch | |
421cee29 | 2633 | * @prev: the current task that is being switched out |
4866cde0 NP |
2634 | * @next: the task we are going to switch to. |
2635 | * | |
2636 | * This is called with the rq lock held and interrupts off. It must | |
2637 | * be paired with a subsequent finish_task_switch after the context | |
2638 | * switch. | |
2639 | * | |
2640 | * prepare_task_switch sets up locking and calls architecture specific | |
2641 | * hooks. | |
2642 | */ | |
e107be36 AK |
2643 | static inline void |
2644 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2645 | struct task_struct *next) | |
4866cde0 | 2646 | { |
e107be36 | 2647 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2648 | prepare_lock_switch(rq, next); |
2649 | prepare_arch_switch(next); | |
2650 | } | |
2651 | ||
1da177e4 LT |
2652 | /** |
2653 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2654 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2655 | * @prev: the thread we just switched away from. |
2656 | * | |
4866cde0 NP |
2657 | * finish_task_switch must be called after the context switch, paired |
2658 | * with a prepare_task_switch call before the context switch. | |
2659 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2660 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2661 | * |
2662 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2663 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2664 | * with the lock held can cause deadlocks; see schedule() for |
2665 | * details.) | |
2666 | */ | |
a9957449 | 2667 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2668 | __releases(rq->lock) |
2669 | { | |
1da177e4 | 2670 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2671 | long prev_state; |
1da177e4 LT |
2672 | |
2673 | rq->prev_mm = NULL; | |
2674 | ||
2675 | /* | |
2676 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2677 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2678 | * schedule one last time. The schedule call will never return, and |
2679 | * the scheduled task must drop that reference. | |
c394cc9f | 2680 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2681 | * still held, otherwise prev could be scheduled on another cpu, die |
2682 | * there before we look at prev->state, and then the reference would | |
2683 | * be dropped twice. | |
2684 | * Manfred Spraul <manfred@colorfullife.com> | |
2685 | */ | |
55a101f8 | 2686 | prev_state = prev->state; |
4866cde0 | 2687 | finish_arch_switch(prev); |
8381f65d JI |
2688 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2689 | local_irq_disable(); | |
2690 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
49f47433 | 2691 | perf_event_task_sched_in(current); |
8381f65d JI |
2692 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2693 | local_irq_enable(); | |
2694 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 2695 | finish_lock_switch(rq, prev); |
e8fa1362 | 2696 | |
e107be36 | 2697 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2698 | if (mm) |
2699 | mmdrop(mm); | |
c394cc9f | 2700 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2701 | /* |
2702 | * Remove function-return probe instances associated with this | |
2703 | * task and put them back on the free list. | |
9761eea8 | 2704 | */ |
c6fd91f0 | 2705 | kprobe_flush_task(prev); |
1da177e4 | 2706 | put_task_struct(prev); |
c6fd91f0 | 2707 | } |
1da177e4 LT |
2708 | } |
2709 | ||
3f029d3c GH |
2710 | #ifdef CONFIG_SMP |
2711 | ||
2712 | /* assumes rq->lock is held */ | |
2713 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2714 | { | |
2715 | if (prev->sched_class->pre_schedule) | |
2716 | prev->sched_class->pre_schedule(rq, prev); | |
2717 | } | |
2718 | ||
2719 | /* rq->lock is NOT held, but preemption is disabled */ | |
2720 | static inline void post_schedule(struct rq *rq) | |
2721 | { | |
2722 | if (rq->post_schedule) { | |
2723 | unsigned long flags; | |
2724 | ||
05fa785c | 2725 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2726 | if (rq->curr->sched_class->post_schedule) |
2727 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2728 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2729 | |
2730 | rq->post_schedule = 0; | |
2731 | } | |
2732 | } | |
2733 | ||
2734 | #else | |
da19ab51 | 2735 | |
3f029d3c GH |
2736 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2737 | { | |
2738 | } | |
2739 | ||
2740 | static inline void post_schedule(struct rq *rq) | |
2741 | { | |
1da177e4 LT |
2742 | } |
2743 | ||
3f029d3c GH |
2744 | #endif |
2745 | ||
1da177e4 LT |
2746 | /** |
2747 | * schedule_tail - first thing a freshly forked thread must call. | |
2748 | * @prev: the thread we just switched away from. | |
2749 | */ | |
36c8b586 | 2750 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2751 | __releases(rq->lock) |
2752 | { | |
70b97a7f IM |
2753 | struct rq *rq = this_rq(); |
2754 | ||
4866cde0 | 2755 | finish_task_switch(rq, prev); |
da19ab51 | 2756 | |
3f029d3c GH |
2757 | /* |
2758 | * FIXME: do we need to worry about rq being invalidated by the | |
2759 | * task_switch? | |
2760 | */ | |
2761 | post_schedule(rq); | |
70b97a7f | 2762 | |
4866cde0 NP |
2763 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2764 | /* In this case, finish_task_switch does not reenable preemption */ | |
2765 | preempt_enable(); | |
2766 | #endif | |
1da177e4 | 2767 | if (current->set_child_tid) |
b488893a | 2768 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2769 | } |
2770 | ||
2771 | /* | |
2772 | * context_switch - switch to the new MM and the new | |
2773 | * thread's register state. | |
2774 | */ | |
dd41f596 | 2775 | static inline void |
70b97a7f | 2776 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2777 | struct task_struct *next) |
1da177e4 | 2778 | { |
dd41f596 | 2779 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2780 | |
e107be36 | 2781 | prepare_task_switch(rq, prev, next); |
27a9da65 | 2782 | trace_sched_switch(prev, next); |
dd41f596 IM |
2783 | mm = next->mm; |
2784 | oldmm = prev->active_mm; | |
9226d125 ZA |
2785 | /* |
2786 | * For paravirt, this is coupled with an exit in switch_to to | |
2787 | * combine the page table reload and the switch backend into | |
2788 | * one hypercall. | |
2789 | */ | |
224101ed | 2790 | arch_start_context_switch(prev); |
9226d125 | 2791 | |
710390d9 | 2792 | if (likely(!mm)) { |
1da177e4 LT |
2793 | next->active_mm = oldmm; |
2794 | atomic_inc(&oldmm->mm_count); | |
2795 | enter_lazy_tlb(oldmm, next); | |
2796 | } else | |
2797 | switch_mm(oldmm, mm, next); | |
2798 | ||
710390d9 | 2799 | if (likely(!prev->mm)) { |
1da177e4 | 2800 | prev->active_mm = NULL; |
1da177e4 LT |
2801 | rq->prev_mm = oldmm; |
2802 | } | |
3a5f5e48 IM |
2803 | /* |
2804 | * Since the runqueue lock will be released by the next | |
2805 | * task (which is an invalid locking op but in the case | |
2806 | * of the scheduler it's an obvious special-case), so we | |
2807 | * do an early lockdep release here: | |
2808 | */ | |
2809 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2810 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2811 | #endif |
1da177e4 LT |
2812 | |
2813 | /* Here we just switch the register state and the stack. */ | |
2814 | switch_to(prev, next, prev); | |
2815 | ||
dd41f596 IM |
2816 | barrier(); |
2817 | /* | |
2818 | * this_rq must be evaluated again because prev may have moved | |
2819 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2820 | * frame will be invalid. | |
2821 | */ | |
2822 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2823 | } |
2824 | ||
2825 | /* | |
2826 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2827 | * | |
2828 | * externally visible scheduler statistics: current number of runnable | |
2829 | * threads, current number of uninterruptible-sleeping threads, total | |
2830 | * number of context switches performed since bootup. | |
2831 | */ | |
2832 | unsigned long nr_running(void) | |
2833 | { | |
2834 | unsigned long i, sum = 0; | |
2835 | ||
2836 | for_each_online_cpu(i) | |
2837 | sum += cpu_rq(i)->nr_running; | |
2838 | ||
2839 | return sum; | |
f711f609 | 2840 | } |
1da177e4 LT |
2841 | |
2842 | unsigned long nr_uninterruptible(void) | |
f711f609 | 2843 | { |
1da177e4 | 2844 | unsigned long i, sum = 0; |
f711f609 | 2845 | |
0a945022 | 2846 | for_each_possible_cpu(i) |
1da177e4 | 2847 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
2848 | |
2849 | /* | |
1da177e4 LT |
2850 | * Since we read the counters lockless, it might be slightly |
2851 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 2852 | */ |
1da177e4 LT |
2853 | if (unlikely((long)sum < 0)) |
2854 | sum = 0; | |
f711f609 | 2855 | |
1da177e4 | 2856 | return sum; |
f711f609 | 2857 | } |
f711f609 | 2858 | |
1da177e4 | 2859 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2860 | { |
cc94abfc SR |
2861 | int i; |
2862 | unsigned long long sum = 0; | |
46cb4b7c | 2863 | |
0a945022 | 2864 | for_each_possible_cpu(i) |
1da177e4 | 2865 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2866 | |
1da177e4 LT |
2867 | return sum; |
2868 | } | |
483b4ee6 | 2869 | |
1da177e4 LT |
2870 | unsigned long nr_iowait(void) |
2871 | { | |
2872 | unsigned long i, sum = 0; | |
483b4ee6 | 2873 | |
0a945022 | 2874 | for_each_possible_cpu(i) |
1da177e4 | 2875 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2876 | |
1da177e4 LT |
2877 | return sum; |
2878 | } | |
483b4ee6 | 2879 | |
69d25870 AV |
2880 | unsigned long nr_iowait_cpu(void) |
2881 | { | |
2882 | struct rq *this = this_rq(); | |
2883 | return atomic_read(&this->nr_iowait); | |
2884 | } | |
46cb4b7c | 2885 | |
69d25870 AV |
2886 | unsigned long this_cpu_load(void) |
2887 | { | |
2888 | struct rq *this = this_rq(); | |
2889 | return this->cpu_load[0]; | |
2890 | } | |
e790fb0b | 2891 | |
46cb4b7c | 2892 | |
dce48a84 TG |
2893 | /* Variables and functions for calc_load */ |
2894 | static atomic_long_t calc_load_tasks; | |
2895 | static unsigned long calc_load_update; | |
2896 | unsigned long avenrun[3]; | |
2897 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 2898 | |
74f5187a PZ |
2899 | static long calc_load_fold_active(struct rq *this_rq) |
2900 | { | |
2901 | long nr_active, delta = 0; | |
2902 | ||
2903 | nr_active = this_rq->nr_running; | |
2904 | nr_active += (long) this_rq->nr_uninterruptible; | |
2905 | ||
2906 | if (nr_active != this_rq->calc_load_active) { | |
2907 | delta = nr_active - this_rq->calc_load_active; | |
2908 | this_rq->calc_load_active = nr_active; | |
2909 | } | |
2910 | ||
2911 | return delta; | |
2912 | } | |
2913 | ||
2914 | #ifdef CONFIG_NO_HZ | |
2915 | /* | |
2916 | * For NO_HZ we delay the active fold to the next LOAD_FREQ update. | |
2917 | * | |
2918 | * When making the ILB scale, we should try to pull this in as well. | |
2919 | */ | |
2920 | static atomic_long_t calc_load_tasks_idle; | |
2921 | ||
2922 | static void calc_load_account_idle(struct rq *this_rq) | |
2923 | { | |
2924 | long delta; | |
2925 | ||
2926 | delta = calc_load_fold_active(this_rq); | |
2927 | if (delta) | |
2928 | atomic_long_add(delta, &calc_load_tasks_idle); | |
2929 | } | |
2930 | ||
2931 | static long calc_load_fold_idle(void) | |
2932 | { | |
2933 | long delta = 0; | |
2934 | ||
2935 | /* | |
2936 | * Its got a race, we don't care... | |
2937 | */ | |
2938 | if (atomic_long_read(&calc_load_tasks_idle)) | |
2939 | delta = atomic_long_xchg(&calc_load_tasks_idle, 0); | |
2940 | ||
2941 | return delta; | |
2942 | } | |
2943 | #else | |
2944 | static void calc_load_account_idle(struct rq *this_rq) | |
2945 | { | |
2946 | } | |
2947 | ||
2948 | static inline long calc_load_fold_idle(void) | |
2949 | { | |
2950 | return 0; | |
2951 | } | |
2952 | #endif | |
2953 | ||
2d02494f TG |
2954 | /** |
2955 | * get_avenrun - get the load average array | |
2956 | * @loads: pointer to dest load array | |
2957 | * @offset: offset to add | |
2958 | * @shift: shift count to shift the result left | |
2959 | * | |
2960 | * These values are estimates at best, so no need for locking. | |
2961 | */ | |
2962 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
2963 | { | |
2964 | loads[0] = (avenrun[0] + offset) << shift; | |
2965 | loads[1] = (avenrun[1] + offset) << shift; | |
2966 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 2967 | } |
46cb4b7c | 2968 | |
dce48a84 TG |
2969 | static unsigned long |
2970 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 2971 | { |
dce48a84 TG |
2972 | load *= exp; |
2973 | load += active * (FIXED_1 - exp); | |
2974 | return load >> FSHIFT; | |
2975 | } | |
46cb4b7c SS |
2976 | |
2977 | /* | |
dce48a84 TG |
2978 | * calc_load - update the avenrun load estimates 10 ticks after the |
2979 | * CPUs have updated calc_load_tasks. | |
7835b98b | 2980 | */ |
dce48a84 | 2981 | void calc_global_load(void) |
7835b98b | 2982 | { |
dce48a84 TG |
2983 | unsigned long upd = calc_load_update + 10; |
2984 | long active; | |
1da177e4 | 2985 | |
dce48a84 TG |
2986 | if (time_before(jiffies, upd)) |
2987 | return; | |
1da177e4 | 2988 | |
dce48a84 TG |
2989 | active = atomic_long_read(&calc_load_tasks); |
2990 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 2991 | |
dce48a84 TG |
2992 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
2993 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
2994 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 2995 | |
dce48a84 TG |
2996 | calc_load_update += LOAD_FREQ; |
2997 | } | |
1da177e4 | 2998 | |
dce48a84 | 2999 | /* |
74f5187a PZ |
3000 | * Called from update_cpu_load() to periodically update this CPU's |
3001 | * active count. | |
dce48a84 TG |
3002 | */ |
3003 | static void calc_load_account_active(struct rq *this_rq) | |
3004 | { | |
74f5187a | 3005 | long delta; |
08c183f3 | 3006 | |
74f5187a PZ |
3007 | if (time_before(jiffies, this_rq->calc_load_update)) |
3008 | return; | |
783609c6 | 3009 | |
74f5187a PZ |
3010 | delta = calc_load_fold_active(this_rq); |
3011 | delta += calc_load_fold_idle(); | |
3012 | if (delta) | |
dce48a84 | 3013 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
3014 | |
3015 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
3016 | } |
3017 | ||
3018 | /* | |
dd41f596 IM |
3019 | * Update rq->cpu_load[] statistics. This function is usually called every |
3020 | * scheduler tick (TICK_NSEC). | |
46cb4b7c | 3021 | */ |
dd41f596 | 3022 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3023 | { |
495eca49 | 3024 | unsigned long this_load = this_rq->load.weight; |
dd41f596 | 3025 | int i, scale; |
46cb4b7c | 3026 | |
dd41f596 | 3027 | this_rq->nr_load_updates++; |
46cb4b7c | 3028 | |
dd41f596 IM |
3029 | /* Update our load: */ |
3030 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
3031 | unsigned long old_load, new_load; | |
7d1e6a9b | 3032 | |
dd41f596 | 3033 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3034 | |
dd41f596 IM |
3035 | old_load = this_rq->cpu_load[i]; |
3036 | new_load = this_load; | |
a25707f3 IM |
3037 | /* |
3038 | * Round up the averaging division if load is increasing. This | |
3039 | * prevents us from getting stuck on 9 if the load is 10, for | |
3040 | * example. | |
3041 | */ | |
3042 | if (new_load > old_load) | |
3043 | new_load += scale-1; | |
dd41f596 IM |
3044 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
3045 | } | |
46cb4b7c | 3046 | |
74f5187a | 3047 | calc_load_account_active(this_rq); |
46cb4b7c SS |
3048 | } |
3049 | ||
dd41f596 | 3050 | #ifdef CONFIG_SMP |
8a0be9ef | 3051 | |
46cb4b7c | 3052 | /* |
38022906 PZ |
3053 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3054 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3055 | */ |
38022906 | 3056 | void sched_exec(void) |
46cb4b7c | 3057 | { |
38022906 | 3058 | struct task_struct *p = current; |
1da177e4 | 3059 | unsigned long flags; |
70b97a7f | 3060 | struct rq *rq; |
0017d735 | 3061 | int dest_cpu; |
46cb4b7c | 3062 | |
1da177e4 | 3063 | rq = task_rq_lock(p, &flags); |
0017d735 PZ |
3064 | dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0); |
3065 | if (dest_cpu == smp_processor_id()) | |
3066 | goto unlock; | |
38022906 | 3067 | |
46cb4b7c | 3068 | /* |
38022906 | 3069 | * select_task_rq() can race against ->cpus_allowed |
46cb4b7c | 3070 | */ |
30da688e | 3071 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) && |
969c7921 TH |
3072 | likely(cpu_active(dest_cpu)) && migrate_task(p, dest_cpu)) { |
3073 | struct migration_arg arg = { p, dest_cpu }; | |
46cb4b7c | 3074 | |
1da177e4 | 3075 | task_rq_unlock(rq, &flags); |
969c7921 | 3076 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
3077 | return; |
3078 | } | |
0017d735 | 3079 | unlock: |
1da177e4 | 3080 | task_rq_unlock(rq, &flags); |
1da177e4 | 3081 | } |
dd41f596 | 3082 | |
1da177e4 LT |
3083 | #endif |
3084 | ||
1da177e4 LT |
3085 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3086 | ||
3087 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3088 | ||
3089 | /* | |
c5f8d995 | 3090 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3091 | * @p in case that task is currently running. |
c5f8d995 HS |
3092 | * |
3093 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3094 | */ |
c5f8d995 HS |
3095 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3096 | { | |
3097 | u64 ns = 0; | |
3098 | ||
3099 | if (task_current(rq, p)) { | |
3100 | update_rq_clock(rq); | |
3101 | ns = rq->clock - p->se.exec_start; | |
3102 | if ((s64)ns < 0) | |
3103 | ns = 0; | |
3104 | } | |
3105 | ||
3106 | return ns; | |
3107 | } | |
3108 | ||
bb34d92f | 3109 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3110 | { |
1da177e4 | 3111 | unsigned long flags; |
41b86e9c | 3112 | struct rq *rq; |
bb34d92f | 3113 | u64 ns = 0; |
48f24c4d | 3114 | |
41b86e9c | 3115 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
3116 | ns = do_task_delta_exec(p, rq); |
3117 | task_rq_unlock(rq, &flags); | |
1508487e | 3118 | |
c5f8d995 HS |
3119 | return ns; |
3120 | } | |
f06febc9 | 3121 | |
c5f8d995 HS |
3122 | /* |
3123 | * Return accounted runtime for the task. | |
3124 | * In case the task is currently running, return the runtime plus current's | |
3125 | * pending runtime that have not been accounted yet. | |
3126 | */ | |
3127 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3128 | { | |
3129 | unsigned long flags; | |
3130 | struct rq *rq; | |
3131 | u64 ns = 0; | |
3132 | ||
3133 | rq = task_rq_lock(p, &flags); | |
3134 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
3135 | task_rq_unlock(rq, &flags); | |
3136 | ||
3137 | return ns; | |
3138 | } | |
48f24c4d | 3139 | |
c5f8d995 HS |
3140 | /* |
3141 | * Return sum_exec_runtime for the thread group. | |
3142 | * In case the task is currently running, return the sum plus current's | |
3143 | * pending runtime that have not been accounted yet. | |
3144 | * | |
3145 | * Note that the thread group might have other running tasks as well, | |
3146 | * so the return value not includes other pending runtime that other | |
3147 | * running tasks might have. | |
3148 | */ | |
3149 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
3150 | { | |
3151 | struct task_cputime totals; | |
3152 | unsigned long flags; | |
3153 | struct rq *rq; | |
3154 | u64 ns; | |
3155 | ||
3156 | rq = task_rq_lock(p, &flags); | |
3157 | thread_group_cputime(p, &totals); | |
3158 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 3159 | task_rq_unlock(rq, &flags); |
48f24c4d | 3160 | |
1da177e4 LT |
3161 | return ns; |
3162 | } | |
3163 | ||
1da177e4 LT |
3164 | /* |
3165 | * Account user cpu time to a process. | |
3166 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3167 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3168 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3169 | */ |
457533a7 MS |
3170 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3171 | cputime_t cputime_scaled) | |
1da177e4 LT |
3172 | { |
3173 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3174 | cputime64_t tmp; | |
3175 | ||
457533a7 | 3176 | /* Add user time to process. */ |
1da177e4 | 3177 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3178 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3179 | account_group_user_time(p, cputime); |
1da177e4 LT |
3180 | |
3181 | /* Add user time to cpustat. */ | |
3182 | tmp = cputime_to_cputime64(cputime); | |
3183 | if (TASK_NICE(p) > 0) | |
3184 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3185 | else | |
3186 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
3187 | |
3188 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3189 | /* Account for user time used */ |
3190 | acct_update_integrals(p); | |
1da177e4 LT |
3191 | } |
3192 | ||
94886b84 LV |
3193 | /* |
3194 | * Account guest cpu time to a process. | |
3195 | * @p: the process that the cpu time gets accounted to | |
3196 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3197 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3198 | */ |
457533a7 MS |
3199 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3200 | cputime_t cputime_scaled) | |
94886b84 LV |
3201 | { |
3202 | cputime64_t tmp; | |
3203 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3204 | ||
3205 | tmp = cputime_to_cputime64(cputime); | |
3206 | ||
457533a7 | 3207 | /* Add guest time to process. */ |
94886b84 | 3208 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3209 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3210 | account_group_user_time(p, cputime); |
94886b84 LV |
3211 | p->gtime = cputime_add(p->gtime, cputime); |
3212 | ||
457533a7 | 3213 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
3214 | if (TASK_NICE(p) > 0) { |
3215 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3216 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
3217 | } else { | |
3218 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
3219 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
3220 | } | |
94886b84 LV |
3221 | } |
3222 | ||
1da177e4 LT |
3223 | /* |
3224 | * Account system cpu time to a process. | |
3225 | * @p: the process that the cpu time gets accounted to | |
3226 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3227 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3228 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3229 | */ |
3230 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3231 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3232 | { |
3233 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
3234 | cputime64_t tmp; |
3235 | ||
983ed7a6 | 3236 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3237 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3238 | return; |
3239 | } | |
94886b84 | 3240 | |
457533a7 | 3241 | /* Add system time to process. */ |
1da177e4 | 3242 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 3243 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 3244 | account_group_system_time(p, cputime); |
1da177e4 LT |
3245 | |
3246 | /* Add system time to cpustat. */ | |
3247 | tmp = cputime_to_cputime64(cputime); | |
3248 | if (hardirq_count() - hardirq_offset) | |
3249 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
3250 | else if (softirq_count()) | |
3251 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 3252 | else |
79741dd3 MS |
3253 | cpustat->system = cputime64_add(cpustat->system, tmp); |
3254 | ||
ef12fefa BR |
3255 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
3256 | ||
1da177e4 LT |
3257 | /* Account for system time used */ |
3258 | acct_update_integrals(p); | |
1da177e4 LT |
3259 | } |
3260 | ||
c66f08be | 3261 | /* |
1da177e4 | 3262 | * Account for involuntary wait time. |
1da177e4 | 3263 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 3264 | */ |
79741dd3 | 3265 | void account_steal_time(cputime_t cputime) |
c66f08be | 3266 | { |
79741dd3 MS |
3267 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3268 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
3269 | ||
3270 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
3271 | } |
3272 | ||
1da177e4 | 3273 | /* |
79741dd3 MS |
3274 | * Account for idle time. |
3275 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3276 | */ |
79741dd3 | 3277 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3278 | { |
3279 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 3280 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 3281 | struct rq *rq = this_rq(); |
1da177e4 | 3282 | |
79741dd3 MS |
3283 | if (atomic_read(&rq->nr_iowait) > 0) |
3284 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
3285 | else | |
3286 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
3287 | } |
3288 | ||
79741dd3 MS |
3289 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
3290 | ||
3291 | /* | |
3292 | * Account a single tick of cpu time. | |
3293 | * @p: the process that the cpu time gets accounted to | |
3294 | * @user_tick: indicates if the tick is a user or a system tick | |
3295 | */ | |
3296 | void account_process_tick(struct task_struct *p, int user_tick) | |
3297 | { | |
a42548a1 | 3298 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
3299 | struct rq *rq = this_rq(); |
3300 | ||
3301 | if (user_tick) | |
a42548a1 | 3302 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 3303 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 3304 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
3305 | one_jiffy_scaled); |
3306 | else | |
a42548a1 | 3307 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
3308 | } |
3309 | ||
3310 | /* | |
3311 | * Account multiple ticks of steal time. | |
3312 | * @p: the process from which the cpu time has been stolen | |
3313 | * @ticks: number of stolen ticks | |
3314 | */ | |
3315 | void account_steal_ticks(unsigned long ticks) | |
3316 | { | |
3317 | account_steal_time(jiffies_to_cputime(ticks)); | |
3318 | } | |
3319 | ||
3320 | /* | |
3321 | * Account multiple ticks of idle time. | |
3322 | * @ticks: number of stolen ticks | |
3323 | */ | |
3324 | void account_idle_ticks(unsigned long ticks) | |
3325 | { | |
3326 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
3327 | } |
3328 | ||
79741dd3 MS |
3329 | #endif |
3330 | ||
49048622 BS |
3331 | /* |
3332 | * Use precise platform statistics if available: | |
3333 | */ | |
3334 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 3335 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3336 | { |
d99ca3b9 HS |
3337 | *ut = p->utime; |
3338 | *st = p->stime; | |
49048622 BS |
3339 | } |
3340 | ||
0cf55e1e | 3341 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3342 | { |
0cf55e1e HS |
3343 | struct task_cputime cputime; |
3344 | ||
3345 | thread_group_cputime(p, &cputime); | |
3346 | ||
3347 | *ut = cputime.utime; | |
3348 | *st = cputime.stime; | |
49048622 BS |
3349 | } |
3350 | #else | |
761b1d26 HS |
3351 | |
3352 | #ifndef nsecs_to_cputime | |
b7b20df9 | 3353 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
3354 | #endif |
3355 | ||
d180c5bc | 3356 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3357 | { |
d99ca3b9 | 3358 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
3359 | |
3360 | /* | |
3361 | * Use CFS's precise accounting: | |
3362 | */ | |
d180c5bc | 3363 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
3364 | |
3365 | if (total) { | |
d180c5bc HS |
3366 | u64 temp; |
3367 | ||
3368 | temp = (u64)(rtime * utime); | |
49048622 | 3369 | do_div(temp, total); |
d180c5bc HS |
3370 | utime = (cputime_t)temp; |
3371 | } else | |
3372 | utime = rtime; | |
49048622 | 3373 | |
d180c5bc HS |
3374 | /* |
3375 | * Compare with previous values, to keep monotonicity: | |
3376 | */ | |
761b1d26 | 3377 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 3378 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 3379 | |
d99ca3b9 HS |
3380 | *ut = p->prev_utime; |
3381 | *st = p->prev_stime; | |
49048622 BS |
3382 | } |
3383 | ||
0cf55e1e HS |
3384 | /* |
3385 | * Must be called with siglock held. | |
3386 | */ | |
3387 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 3388 | { |
0cf55e1e HS |
3389 | struct signal_struct *sig = p->signal; |
3390 | struct task_cputime cputime; | |
3391 | cputime_t rtime, utime, total; | |
49048622 | 3392 | |
0cf55e1e | 3393 | thread_group_cputime(p, &cputime); |
49048622 | 3394 | |
0cf55e1e HS |
3395 | total = cputime_add(cputime.utime, cputime.stime); |
3396 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 3397 | |
0cf55e1e HS |
3398 | if (total) { |
3399 | u64 temp; | |
49048622 | 3400 | |
0cf55e1e HS |
3401 | temp = (u64)(rtime * cputime.utime); |
3402 | do_div(temp, total); | |
3403 | utime = (cputime_t)temp; | |
3404 | } else | |
3405 | utime = rtime; | |
3406 | ||
3407 | sig->prev_utime = max(sig->prev_utime, utime); | |
3408 | sig->prev_stime = max(sig->prev_stime, | |
3409 | cputime_sub(rtime, sig->prev_utime)); | |
3410 | ||
3411 | *ut = sig->prev_utime; | |
3412 | *st = sig->prev_stime; | |
49048622 | 3413 | } |
49048622 | 3414 | #endif |
49048622 | 3415 | |
7835b98b CL |
3416 | /* |
3417 | * This function gets called by the timer code, with HZ frequency. | |
3418 | * We call it with interrupts disabled. | |
3419 | * | |
3420 | * It also gets called by the fork code, when changing the parent's | |
3421 | * timeslices. | |
3422 | */ | |
3423 | void scheduler_tick(void) | |
3424 | { | |
7835b98b CL |
3425 | int cpu = smp_processor_id(); |
3426 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 3427 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
3428 | |
3429 | sched_clock_tick(); | |
dd41f596 | 3430 | |
05fa785c | 3431 | raw_spin_lock(&rq->lock); |
3e51f33f | 3432 | update_rq_clock(rq); |
f1a438d8 | 3433 | update_cpu_load(rq); |
fa85ae24 | 3434 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 3435 | raw_spin_unlock(&rq->lock); |
7835b98b | 3436 | |
49f47433 | 3437 | perf_event_task_tick(curr); |
e220d2dc | 3438 | |
e418e1c2 | 3439 | #ifdef CONFIG_SMP |
dd41f596 IM |
3440 | rq->idle_at_tick = idle_cpu(cpu); |
3441 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 3442 | #endif |
1da177e4 LT |
3443 | } |
3444 | ||
132380a0 | 3445 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
3446 | { |
3447 | if (in_lock_functions(addr)) { | |
3448 | addr = CALLER_ADDR2; | |
3449 | if (in_lock_functions(addr)) | |
3450 | addr = CALLER_ADDR3; | |
3451 | } | |
3452 | return addr; | |
3453 | } | |
1da177e4 | 3454 | |
7e49fcce SR |
3455 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
3456 | defined(CONFIG_PREEMPT_TRACER)) | |
3457 | ||
43627582 | 3458 | void __kprobes add_preempt_count(int val) |
1da177e4 | 3459 | { |
6cd8a4bb | 3460 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3461 | /* |
3462 | * Underflow? | |
3463 | */ | |
9a11b49a IM |
3464 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
3465 | return; | |
6cd8a4bb | 3466 | #endif |
1da177e4 | 3467 | preempt_count() += val; |
6cd8a4bb | 3468 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3469 | /* |
3470 | * Spinlock count overflowing soon? | |
3471 | */ | |
33859f7f MOS |
3472 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
3473 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
3474 | #endif |
3475 | if (preempt_count() == val) | |
3476 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3477 | } |
3478 | EXPORT_SYMBOL(add_preempt_count); | |
3479 | ||
43627582 | 3480 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 3481 | { |
6cd8a4bb | 3482 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3483 | /* |
3484 | * Underflow? | |
3485 | */ | |
01e3eb82 | 3486 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 3487 | return; |
1da177e4 LT |
3488 | /* |
3489 | * Is the spinlock portion underflowing? | |
3490 | */ | |
9a11b49a IM |
3491 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
3492 | !(preempt_count() & PREEMPT_MASK))) | |
3493 | return; | |
6cd8a4bb | 3494 | #endif |
9a11b49a | 3495 | |
6cd8a4bb SR |
3496 | if (preempt_count() == val) |
3497 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3498 | preempt_count() -= val; |
3499 | } | |
3500 | EXPORT_SYMBOL(sub_preempt_count); | |
3501 | ||
3502 | #endif | |
3503 | ||
3504 | /* | |
dd41f596 | 3505 | * Print scheduling while atomic bug: |
1da177e4 | 3506 | */ |
dd41f596 | 3507 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 3508 | { |
838225b4 SS |
3509 | struct pt_regs *regs = get_irq_regs(); |
3510 | ||
3df0fc5b PZ |
3511 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
3512 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 3513 | |
dd41f596 | 3514 | debug_show_held_locks(prev); |
e21f5b15 | 3515 | print_modules(); |
dd41f596 IM |
3516 | if (irqs_disabled()) |
3517 | print_irqtrace_events(prev); | |
838225b4 SS |
3518 | |
3519 | if (regs) | |
3520 | show_regs(regs); | |
3521 | else | |
3522 | dump_stack(); | |
dd41f596 | 3523 | } |
1da177e4 | 3524 | |
dd41f596 IM |
3525 | /* |
3526 | * Various schedule()-time debugging checks and statistics: | |
3527 | */ | |
3528 | static inline void schedule_debug(struct task_struct *prev) | |
3529 | { | |
1da177e4 | 3530 | /* |
41a2d6cf | 3531 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
3532 | * schedule() atomically, we ignore that path for now. |
3533 | * Otherwise, whine if we are scheduling when we should not be. | |
3534 | */ | |
3f33a7ce | 3535 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
3536 | __schedule_bug(prev); |
3537 | ||
1da177e4 LT |
3538 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
3539 | ||
2d72376b | 3540 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
3541 | #ifdef CONFIG_SCHEDSTATS |
3542 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
3543 | schedstat_inc(this_rq(), bkl_count); |
3544 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
3545 | } |
3546 | #endif | |
dd41f596 IM |
3547 | } |
3548 | ||
6cecd084 | 3549 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 3550 | { |
a64692a3 MG |
3551 | if (prev->se.on_rq) |
3552 | update_rq_clock(rq); | |
3553 | rq->skip_clock_update = 0; | |
6cecd084 | 3554 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
3555 | } |
3556 | ||
dd41f596 IM |
3557 | /* |
3558 | * Pick up the highest-prio task: | |
3559 | */ | |
3560 | static inline struct task_struct * | |
b67802ea | 3561 | pick_next_task(struct rq *rq) |
dd41f596 | 3562 | { |
5522d5d5 | 3563 | const struct sched_class *class; |
dd41f596 | 3564 | struct task_struct *p; |
1da177e4 LT |
3565 | |
3566 | /* | |
dd41f596 IM |
3567 | * Optimization: we know that if all tasks are in |
3568 | * the fair class we can call that function directly: | |
1da177e4 | 3569 | */ |
dd41f596 | 3570 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 3571 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
3572 | if (likely(p)) |
3573 | return p; | |
1da177e4 LT |
3574 | } |
3575 | ||
dd41f596 IM |
3576 | class = sched_class_highest; |
3577 | for ( ; ; ) { | |
fb8d4724 | 3578 | p = class->pick_next_task(rq); |
dd41f596 IM |
3579 | if (p) |
3580 | return p; | |
3581 | /* | |
3582 | * Will never be NULL as the idle class always | |
3583 | * returns a non-NULL p: | |
3584 | */ | |
3585 | class = class->next; | |
3586 | } | |
3587 | } | |
1da177e4 | 3588 | |
dd41f596 IM |
3589 | /* |
3590 | * schedule() is the main scheduler function. | |
3591 | */ | |
ff743345 | 3592 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
3593 | { |
3594 | struct task_struct *prev, *next; | |
67ca7bde | 3595 | unsigned long *switch_count; |
dd41f596 | 3596 | struct rq *rq; |
31656519 | 3597 | int cpu; |
dd41f596 | 3598 | |
ff743345 PZ |
3599 | need_resched: |
3600 | preempt_disable(); | |
dd41f596 IM |
3601 | cpu = smp_processor_id(); |
3602 | rq = cpu_rq(cpu); | |
25502a6c | 3603 | rcu_note_context_switch(cpu); |
dd41f596 IM |
3604 | prev = rq->curr; |
3605 | switch_count = &prev->nivcsw; | |
3606 | ||
3607 | release_kernel_lock(prev); | |
3608 | need_resched_nonpreemptible: | |
3609 | ||
3610 | schedule_debug(prev); | |
1da177e4 | 3611 | |
31656519 | 3612 | if (sched_feat(HRTICK)) |
f333fdc9 | 3613 | hrtick_clear(rq); |
8f4d37ec | 3614 | |
05fa785c | 3615 | raw_spin_lock_irq(&rq->lock); |
1e819950 | 3616 | clear_tsk_need_resched(prev); |
1da177e4 | 3617 | |
1da177e4 | 3618 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 3619 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 3620 | prev->state = TASK_RUNNING; |
16882c1e | 3621 | else |
371fd7e7 | 3622 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
dd41f596 | 3623 | switch_count = &prev->nvcsw; |
1da177e4 LT |
3624 | } |
3625 | ||
3f029d3c | 3626 | pre_schedule(rq, prev); |
f65eda4f | 3627 | |
dd41f596 | 3628 | if (unlikely(!rq->nr_running)) |
1da177e4 | 3629 | idle_balance(cpu, rq); |
1da177e4 | 3630 | |
df1c99d4 | 3631 | put_prev_task(rq, prev); |
b67802ea | 3632 | next = pick_next_task(rq); |
1da177e4 | 3633 | |
1da177e4 | 3634 | if (likely(prev != next)) { |
673a90a1 | 3635 | sched_info_switch(prev, next); |
49f47433 | 3636 | perf_event_task_sched_out(prev, next); |
673a90a1 | 3637 | |
1da177e4 LT |
3638 | rq->nr_switches++; |
3639 | rq->curr = next; | |
3640 | ++*switch_count; | |
3641 | ||
dd41f596 | 3642 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
3643 | /* |
3644 | * the context switch might have flipped the stack from under | |
3645 | * us, hence refresh the local variables. | |
3646 | */ | |
3647 | cpu = smp_processor_id(); | |
3648 | rq = cpu_rq(cpu); | |
1da177e4 | 3649 | } else |
05fa785c | 3650 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 3651 | |
3f029d3c | 3652 | post_schedule(rq); |
1da177e4 | 3653 | |
6d558c3a YZ |
3654 | if (unlikely(reacquire_kernel_lock(current) < 0)) { |
3655 | prev = rq->curr; | |
3656 | switch_count = &prev->nivcsw; | |
1da177e4 | 3657 | goto need_resched_nonpreemptible; |
6d558c3a | 3658 | } |
8f4d37ec | 3659 | |
1da177e4 | 3660 | preempt_enable_no_resched(); |
ff743345 | 3661 | if (need_resched()) |
1da177e4 LT |
3662 | goto need_resched; |
3663 | } | |
1da177e4 LT |
3664 | EXPORT_SYMBOL(schedule); |
3665 | ||
c08f7829 | 3666 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d PZ |
3667 | /* |
3668 | * Look out! "owner" is an entirely speculative pointer | |
3669 | * access and not reliable. | |
3670 | */ | |
3671 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
3672 | { | |
3673 | unsigned int cpu; | |
3674 | struct rq *rq; | |
3675 | ||
3676 | if (!sched_feat(OWNER_SPIN)) | |
3677 | return 0; | |
3678 | ||
3679 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3680 | /* | |
3681 | * Need to access the cpu field knowing that | |
3682 | * DEBUG_PAGEALLOC could have unmapped it if | |
3683 | * the mutex owner just released it and exited. | |
3684 | */ | |
3685 | if (probe_kernel_address(&owner->cpu, cpu)) | |
4b402210 | 3686 | return 0; |
0d66bf6d PZ |
3687 | #else |
3688 | cpu = owner->cpu; | |
3689 | #endif | |
3690 | ||
3691 | /* | |
3692 | * Even if the access succeeded (likely case), | |
3693 | * the cpu field may no longer be valid. | |
3694 | */ | |
3695 | if (cpu >= nr_cpumask_bits) | |
4b402210 | 3696 | return 0; |
0d66bf6d PZ |
3697 | |
3698 | /* | |
3699 | * We need to validate that we can do a | |
3700 | * get_cpu() and that we have the percpu area. | |
3701 | */ | |
3702 | if (!cpu_online(cpu)) | |
4b402210 | 3703 | return 0; |
0d66bf6d PZ |
3704 | |
3705 | rq = cpu_rq(cpu); | |
3706 | ||
3707 | for (;;) { | |
3708 | /* | |
3709 | * Owner changed, break to re-assess state. | |
3710 | */ | |
3711 | if (lock->owner != owner) | |
3712 | break; | |
3713 | ||
3714 | /* | |
3715 | * Is that owner really running on that cpu? | |
3716 | */ | |
3717 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
3718 | return 0; | |
3719 | ||
3720 | cpu_relax(); | |
3721 | } | |
4b402210 | 3722 | |
0d66bf6d PZ |
3723 | return 1; |
3724 | } | |
3725 | #endif | |
3726 | ||
1da177e4 LT |
3727 | #ifdef CONFIG_PREEMPT |
3728 | /* | |
2ed6e34f | 3729 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 3730 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
3731 | * occur there and call schedule directly. |
3732 | */ | |
d1f74e20 | 3733 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
3734 | { |
3735 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3736 | |
1da177e4 LT |
3737 | /* |
3738 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 3739 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 3740 | */ |
beed33a8 | 3741 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
3742 | return; |
3743 | ||
3a5c359a | 3744 | do { |
d1f74e20 | 3745 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
3a5c359a | 3746 | schedule(); |
d1f74e20 | 3747 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 3748 | |
3a5c359a AK |
3749 | /* |
3750 | * Check again in case we missed a preemption opportunity | |
3751 | * between schedule and now. | |
3752 | */ | |
3753 | barrier(); | |
5ed0cec0 | 3754 | } while (need_resched()); |
1da177e4 | 3755 | } |
1da177e4 LT |
3756 | EXPORT_SYMBOL(preempt_schedule); |
3757 | ||
3758 | /* | |
2ed6e34f | 3759 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
3760 | * off of irq context. |
3761 | * Note, that this is called and return with irqs disabled. This will | |
3762 | * protect us against recursive calling from irq. | |
3763 | */ | |
3764 | asmlinkage void __sched preempt_schedule_irq(void) | |
3765 | { | |
3766 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3767 | |
2ed6e34f | 3768 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
3769 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
3770 | ||
3a5c359a AK |
3771 | do { |
3772 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
3773 | local_irq_enable(); |
3774 | schedule(); | |
3775 | local_irq_disable(); | |
3a5c359a | 3776 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3777 | |
3a5c359a AK |
3778 | /* |
3779 | * Check again in case we missed a preemption opportunity | |
3780 | * between schedule and now. | |
3781 | */ | |
3782 | barrier(); | |
5ed0cec0 | 3783 | } while (need_resched()); |
1da177e4 LT |
3784 | } |
3785 | ||
3786 | #endif /* CONFIG_PREEMPT */ | |
3787 | ||
63859d4f | 3788 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3789 | void *key) |
1da177e4 | 3790 | { |
63859d4f | 3791 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3792 | } |
1da177e4 LT |
3793 | EXPORT_SYMBOL(default_wake_function); |
3794 | ||
3795 | /* | |
41a2d6cf IM |
3796 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
3797 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
3798 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
3799 | * | |
3800 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 3801 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
3802 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
3803 | */ | |
78ddb08f | 3804 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 3805 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 3806 | { |
2e45874c | 3807 | wait_queue_t *curr, *next; |
1da177e4 | 3808 | |
2e45874c | 3809 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
3810 | unsigned flags = curr->flags; |
3811 | ||
63859d4f | 3812 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 3813 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
3814 | break; |
3815 | } | |
3816 | } | |
3817 | ||
3818 | /** | |
3819 | * __wake_up - wake up threads blocked on a waitqueue. | |
3820 | * @q: the waitqueue | |
3821 | * @mode: which threads | |
3822 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 3823 | * @key: is directly passed to the wakeup function |
50fa610a DH |
3824 | * |
3825 | * It may be assumed that this function implies a write memory barrier before | |
3826 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3827 | */ |
7ad5b3a5 | 3828 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 3829 | int nr_exclusive, void *key) |
1da177e4 LT |
3830 | { |
3831 | unsigned long flags; | |
3832 | ||
3833 | spin_lock_irqsave(&q->lock, flags); | |
3834 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
3835 | spin_unlock_irqrestore(&q->lock, flags); | |
3836 | } | |
1da177e4 LT |
3837 | EXPORT_SYMBOL(__wake_up); |
3838 | ||
3839 | /* | |
3840 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
3841 | */ | |
7ad5b3a5 | 3842 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
3843 | { |
3844 | __wake_up_common(q, mode, 1, 0, NULL); | |
3845 | } | |
22c43c81 | 3846 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 3847 | |
4ede816a DL |
3848 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
3849 | { | |
3850 | __wake_up_common(q, mode, 1, 0, key); | |
3851 | } | |
3852 | ||
1da177e4 | 3853 | /** |
4ede816a | 3854 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
3855 | * @q: the waitqueue |
3856 | * @mode: which threads | |
3857 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 3858 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
3859 | * |
3860 | * The sync wakeup differs that the waker knows that it will schedule | |
3861 | * away soon, so while the target thread will be woken up, it will not | |
3862 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
3863 | * with each other. This can prevent needless bouncing between CPUs. | |
3864 | * | |
3865 | * On UP it can prevent extra preemption. | |
50fa610a DH |
3866 | * |
3867 | * It may be assumed that this function implies a write memory barrier before | |
3868 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3869 | */ |
4ede816a DL |
3870 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
3871 | int nr_exclusive, void *key) | |
1da177e4 LT |
3872 | { |
3873 | unsigned long flags; | |
7d478721 | 3874 | int wake_flags = WF_SYNC; |
1da177e4 LT |
3875 | |
3876 | if (unlikely(!q)) | |
3877 | return; | |
3878 | ||
3879 | if (unlikely(!nr_exclusive)) | |
7d478721 | 3880 | wake_flags = 0; |
1da177e4 LT |
3881 | |
3882 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 3883 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
3884 | spin_unlock_irqrestore(&q->lock, flags); |
3885 | } | |
4ede816a DL |
3886 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
3887 | ||
3888 | /* | |
3889 | * __wake_up_sync - see __wake_up_sync_key() | |
3890 | */ | |
3891 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
3892 | { | |
3893 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
3894 | } | |
1da177e4 LT |
3895 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
3896 | ||
65eb3dc6 KD |
3897 | /** |
3898 | * complete: - signals a single thread waiting on this completion | |
3899 | * @x: holds the state of this particular completion | |
3900 | * | |
3901 | * This will wake up a single thread waiting on this completion. Threads will be | |
3902 | * awakened in the same order in which they were queued. | |
3903 | * | |
3904 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
3905 | * |
3906 | * It may be assumed that this function implies a write memory barrier before | |
3907 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3908 | */ |
b15136e9 | 3909 | void complete(struct completion *x) |
1da177e4 LT |
3910 | { |
3911 | unsigned long flags; | |
3912 | ||
3913 | spin_lock_irqsave(&x->wait.lock, flags); | |
3914 | x->done++; | |
d9514f6c | 3915 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
3916 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3917 | } | |
3918 | EXPORT_SYMBOL(complete); | |
3919 | ||
65eb3dc6 KD |
3920 | /** |
3921 | * complete_all: - signals all threads waiting on this completion | |
3922 | * @x: holds the state of this particular completion | |
3923 | * | |
3924 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
3925 | * |
3926 | * It may be assumed that this function implies a write memory barrier before | |
3927 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3928 | */ |
b15136e9 | 3929 | void complete_all(struct completion *x) |
1da177e4 LT |
3930 | { |
3931 | unsigned long flags; | |
3932 | ||
3933 | spin_lock_irqsave(&x->wait.lock, flags); | |
3934 | x->done += UINT_MAX/2; | |
d9514f6c | 3935 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
3936 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3937 | } | |
3938 | EXPORT_SYMBOL(complete_all); | |
3939 | ||
8cbbe86d AK |
3940 | static inline long __sched |
3941 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3942 | { |
1da177e4 LT |
3943 | if (!x->done) { |
3944 | DECLARE_WAITQUEUE(wait, current); | |
3945 | ||
a93d2f17 | 3946 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 3947 | do { |
94d3d824 | 3948 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
3949 | timeout = -ERESTARTSYS; |
3950 | break; | |
8cbbe86d AK |
3951 | } |
3952 | __set_current_state(state); | |
1da177e4 LT |
3953 | spin_unlock_irq(&x->wait.lock); |
3954 | timeout = schedule_timeout(timeout); | |
3955 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 3956 | } while (!x->done && timeout); |
1da177e4 | 3957 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
3958 | if (!x->done) |
3959 | return timeout; | |
1da177e4 LT |
3960 | } |
3961 | x->done--; | |
ea71a546 | 3962 | return timeout ?: 1; |
1da177e4 | 3963 | } |
1da177e4 | 3964 | |
8cbbe86d AK |
3965 | static long __sched |
3966 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3967 | { |
1da177e4 LT |
3968 | might_sleep(); |
3969 | ||
3970 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 3971 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 3972 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
3973 | return timeout; |
3974 | } | |
1da177e4 | 3975 | |
65eb3dc6 KD |
3976 | /** |
3977 | * wait_for_completion: - waits for completion of a task | |
3978 | * @x: holds the state of this particular completion | |
3979 | * | |
3980 | * This waits to be signaled for completion of a specific task. It is NOT | |
3981 | * interruptible and there is no timeout. | |
3982 | * | |
3983 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
3984 | * and interrupt capability. Also see complete(). | |
3985 | */ | |
b15136e9 | 3986 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
3987 | { |
3988 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 3989 | } |
8cbbe86d | 3990 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 3991 | |
65eb3dc6 KD |
3992 | /** |
3993 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
3994 | * @x: holds the state of this particular completion | |
3995 | * @timeout: timeout value in jiffies | |
3996 | * | |
3997 | * This waits for either a completion of a specific task to be signaled or for a | |
3998 | * specified timeout to expire. The timeout is in jiffies. It is not | |
3999 | * interruptible. | |
4000 | */ | |
b15136e9 | 4001 | unsigned long __sched |
8cbbe86d | 4002 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4003 | { |
8cbbe86d | 4004 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4005 | } |
8cbbe86d | 4006 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4007 | |
65eb3dc6 KD |
4008 | /** |
4009 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4010 | * @x: holds the state of this particular completion | |
4011 | * | |
4012 | * This waits for completion of a specific task to be signaled. It is | |
4013 | * interruptible. | |
4014 | */ | |
8cbbe86d | 4015 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4016 | { |
51e97990 AK |
4017 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4018 | if (t == -ERESTARTSYS) | |
4019 | return t; | |
4020 | return 0; | |
0fec171c | 4021 | } |
8cbbe86d | 4022 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4023 | |
65eb3dc6 KD |
4024 | /** |
4025 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4026 | * @x: holds the state of this particular completion | |
4027 | * @timeout: timeout value in jiffies | |
4028 | * | |
4029 | * This waits for either a completion of a specific task to be signaled or for a | |
4030 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4031 | */ | |
b15136e9 | 4032 | unsigned long __sched |
8cbbe86d AK |
4033 | wait_for_completion_interruptible_timeout(struct completion *x, |
4034 | unsigned long timeout) | |
0fec171c | 4035 | { |
8cbbe86d | 4036 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4037 | } |
8cbbe86d | 4038 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4039 | |
65eb3dc6 KD |
4040 | /** |
4041 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4042 | * @x: holds the state of this particular completion | |
4043 | * | |
4044 | * This waits to be signaled for completion of a specific task. It can be | |
4045 | * interrupted by a kill signal. | |
4046 | */ | |
009e577e MW |
4047 | int __sched wait_for_completion_killable(struct completion *x) |
4048 | { | |
4049 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4050 | if (t == -ERESTARTSYS) | |
4051 | return t; | |
4052 | return 0; | |
4053 | } | |
4054 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4055 | ||
be4de352 DC |
4056 | /** |
4057 | * try_wait_for_completion - try to decrement a completion without blocking | |
4058 | * @x: completion structure | |
4059 | * | |
4060 | * Returns: 0 if a decrement cannot be done without blocking | |
4061 | * 1 if a decrement succeeded. | |
4062 | * | |
4063 | * If a completion is being used as a counting completion, | |
4064 | * attempt to decrement the counter without blocking. This | |
4065 | * enables us to avoid waiting if the resource the completion | |
4066 | * is protecting is not available. | |
4067 | */ | |
4068 | bool try_wait_for_completion(struct completion *x) | |
4069 | { | |
7539a3b3 | 4070 | unsigned long flags; |
be4de352 DC |
4071 | int ret = 1; |
4072 | ||
7539a3b3 | 4073 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4074 | if (!x->done) |
4075 | ret = 0; | |
4076 | else | |
4077 | x->done--; | |
7539a3b3 | 4078 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4079 | return ret; |
4080 | } | |
4081 | EXPORT_SYMBOL(try_wait_for_completion); | |
4082 | ||
4083 | /** | |
4084 | * completion_done - Test to see if a completion has any waiters | |
4085 | * @x: completion structure | |
4086 | * | |
4087 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4088 | * 1 if there are no waiters. | |
4089 | * | |
4090 | */ | |
4091 | bool completion_done(struct completion *x) | |
4092 | { | |
7539a3b3 | 4093 | unsigned long flags; |
be4de352 DC |
4094 | int ret = 1; |
4095 | ||
7539a3b3 | 4096 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4097 | if (!x->done) |
4098 | ret = 0; | |
7539a3b3 | 4099 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4100 | return ret; |
4101 | } | |
4102 | EXPORT_SYMBOL(completion_done); | |
4103 | ||
8cbbe86d AK |
4104 | static long __sched |
4105 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4106 | { |
0fec171c IM |
4107 | unsigned long flags; |
4108 | wait_queue_t wait; | |
4109 | ||
4110 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4111 | |
8cbbe86d | 4112 | __set_current_state(state); |
1da177e4 | 4113 | |
8cbbe86d AK |
4114 | spin_lock_irqsave(&q->lock, flags); |
4115 | __add_wait_queue(q, &wait); | |
4116 | spin_unlock(&q->lock); | |
4117 | timeout = schedule_timeout(timeout); | |
4118 | spin_lock_irq(&q->lock); | |
4119 | __remove_wait_queue(q, &wait); | |
4120 | spin_unlock_irqrestore(&q->lock, flags); | |
4121 | ||
4122 | return timeout; | |
4123 | } | |
4124 | ||
4125 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4126 | { | |
4127 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4128 | } |
1da177e4 LT |
4129 | EXPORT_SYMBOL(interruptible_sleep_on); |
4130 | ||
0fec171c | 4131 | long __sched |
95cdf3b7 | 4132 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4133 | { |
8cbbe86d | 4134 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4135 | } |
1da177e4 LT |
4136 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4137 | ||
0fec171c | 4138 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4139 | { |
8cbbe86d | 4140 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4141 | } |
1da177e4 LT |
4142 | EXPORT_SYMBOL(sleep_on); |
4143 | ||
0fec171c | 4144 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4145 | { |
8cbbe86d | 4146 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4147 | } |
1da177e4 LT |
4148 | EXPORT_SYMBOL(sleep_on_timeout); |
4149 | ||
b29739f9 IM |
4150 | #ifdef CONFIG_RT_MUTEXES |
4151 | ||
4152 | /* | |
4153 | * rt_mutex_setprio - set the current priority of a task | |
4154 | * @p: task | |
4155 | * @prio: prio value (kernel-internal form) | |
4156 | * | |
4157 | * This function changes the 'effective' priority of a task. It does | |
4158 | * not touch ->normal_prio like __setscheduler(). | |
4159 | * | |
4160 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4161 | */ | |
36c8b586 | 4162 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
4163 | { |
4164 | unsigned long flags; | |
83b699ed | 4165 | int oldprio, on_rq, running; |
70b97a7f | 4166 | struct rq *rq; |
83ab0aa0 | 4167 | const struct sched_class *prev_class; |
b29739f9 IM |
4168 | |
4169 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4170 | ||
4171 | rq = task_rq_lock(p, &flags); | |
4172 | ||
d5f9f942 | 4173 | oldprio = p->prio; |
83ab0aa0 | 4174 | prev_class = p->sched_class; |
dd41f596 | 4175 | on_rq = p->se.on_rq; |
051a1d1a | 4176 | running = task_current(rq, p); |
0e1f3483 | 4177 | if (on_rq) |
69be72c1 | 4178 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
4179 | if (running) |
4180 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
4181 | |
4182 | if (rt_prio(prio)) | |
4183 | p->sched_class = &rt_sched_class; | |
4184 | else | |
4185 | p->sched_class = &fair_sched_class; | |
4186 | ||
b29739f9 IM |
4187 | p->prio = prio; |
4188 | ||
0e1f3483 HS |
4189 | if (running) |
4190 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 4191 | if (on_rq) { |
371fd7e7 | 4192 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 SR |
4193 | |
4194 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
4195 | } |
4196 | task_rq_unlock(rq, &flags); | |
4197 | } | |
4198 | ||
4199 | #endif | |
4200 | ||
36c8b586 | 4201 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 4202 | { |
dd41f596 | 4203 | int old_prio, delta, on_rq; |
1da177e4 | 4204 | unsigned long flags; |
70b97a7f | 4205 | struct rq *rq; |
1da177e4 LT |
4206 | |
4207 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
4208 | return; | |
4209 | /* | |
4210 | * We have to be careful, if called from sys_setpriority(), | |
4211 | * the task might be in the middle of scheduling on another CPU. | |
4212 | */ | |
4213 | rq = task_rq_lock(p, &flags); | |
4214 | /* | |
4215 | * The RT priorities are set via sched_setscheduler(), but we still | |
4216 | * allow the 'normal' nice value to be set - but as expected | |
4217 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 4218 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 4219 | */ |
e05606d3 | 4220 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
4221 | p->static_prio = NICE_TO_PRIO(nice); |
4222 | goto out_unlock; | |
4223 | } | |
dd41f596 | 4224 | on_rq = p->se.on_rq; |
c09595f6 | 4225 | if (on_rq) |
69be72c1 | 4226 | dequeue_task(rq, p, 0); |
1da177e4 | 4227 | |
1da177e4 | 4228 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 4229 | set_load_weight(p); |
b29739f9 IM |
4230 | old_prio = p->prio; |
4231 | p->prio = effective_prio(p); | |
4232 | delta = p->prio - old_prio; | |
1da177e4 | 4233 | |
dd41f596 | 4234 | if (on_rq) { |
371fd7e7 | 4235 | enqueue_task(rq, p, 0); |
1da177e4 | 4236 | /* |
d5f9f942 AM |
4237 | * If the task increased its priority or is running and |
4238 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 4239 | */ |
d5f9f942 | 4240 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
4241 | resched_task(rq->curr); |
4242 | } | |
4243 | out_unlock: | |
4244 | task_rq_unlock(rq, &flags); | |
4245 | } | |
1da177e4 LT |
4246 | EXPORT_SYMBOL(set_user_nice); |
4247 | ||
e43379f1 MM |
4248 | /* |
4249 | * can_nice - check if a task can reduce its nice value | |
4250 | * @p: task | |
4251 | * @nice: nice value | |
4252 | */ | |
36c8b586 | 4253 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 4254 | { |
024f4747 MM |
4255 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
4256 | int nice_rlim = 20 - nice; | |
48f24c4d | 4257 | |
78d7d407 | 4258 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
4259 | capable(CAP_SYS_NICE)); |
4260 | } | |
4261 | ||
1da177e4 LT |
4262 | #ifdef __ARCH_WANT_SYS_NICE |
4263 | ||
4264 | /* | |
4265 | * sys_nice - change the priority of the current process. | |
4266 | * @increment: priority increment | |
4267 | * | |
4268 | * sys_setpriority is a more generic, but much slower function that | |
4269 | * does similar things. | |
4270 | */ | |
5add95d4 | 4271 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 4272 | { |
48f24c4d | 4273 | long nice, retval; |
1da177e4 LT |
4274 | |
4275 | /* | |
4276 | * Setpriority might change our priority at the same moment. | |
4277 | * We don't have to worry. Conceptually one call occurs first | |
4278 | * and we have a single winner. | |
4279 | */ | |
e43379f1 MM |
4280 | if (increment < -40) |
4281 | increment = -40; | |
1da177e4 LT |
4282 | if (increment > 40) |
4283 | increment = 40; | |
4284 | ||
2b8f836f | 4285 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
4286 | if (nice < -20) |
4287 | nice = -20; | |
4288 | if (nice > 19) | |
4289 | nice = 19; | |
4290 | ||
e43379f1 MM |
4291 | if (increment < 0 && !can_nice(current, nice)) |
4292 | return -EPERM; | |
4293 | ||
1da177e4 LT |
4294 | retval = security_task_setnice(current, nice); |
4295 | if (retval) | |
4296 | return retval; | |
4297 | ||
4298 | set_user_nice(current, nice); | |
4299 | return 0; | |
4300 | } | |
4301 | ||
4302 | #endif | |
4303 | ||
4304 | /** | |
4305 | * task_prio - return the priority value of a given task. | |
4306 | * @p: the task in question. | |
4307 | * | |
4308 | * This is the priority value as seen by users in /proc. | |
4309 | * RT tasks are offset by -200. Normal tasks are centered | |
4310 | * around 0, value goes from -16 to +15. | |
4311 | */ | |
36c8b586 | 4312 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
4313 | { |
4314 | return p->prio - MAX_RT_PRIO; | |
4315 | } | |
4316 | ||
4317 | /** | |
4318 | * task_nice - return the nice value of a given task. | |
4319 | * @p: the task in question. | |
4320 | */ | |
36c8b586 | 4321 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
4322 | { |
4323 | return TASK_NICE(p); | |
4324 | } | |
150d8bed | 4325 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
4326 | |
4327 | /** | |
4328 | * idle_cpu - is a given cpu idle currently? | |
4329 | * @cpu: the processor in question. | |
4330 | */ | |
4331 | int idle_cpu(int cpu) | |
4332 | { | |
4333 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
4334 | } | |
4335 | ||
1da177e4 LT |
4336 | /** |
4337 | * idle_task - return the idle task for a given cpu. | |
4338 | * @cpu: the processor in question. | |
4339 | */ | |
36c8b586 | 4340 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
4341 | { |
4342 | return cpu_rq(cpu)->idle; | |
4343 | } | |
4344 | ||
4345 | /** | |
4346 | * find_process_by_pid - find a process with a matching PID value. | |
4347 | * @pid: the pid in question. | |
4348 | */ | |
a9957449 | 4349 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 4350 | { |
228ebcbe | 4351 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
4352 | } |
4353 | ||
4354 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
4355 | static void |
4356 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 4357 | { |
dd41f596 | 4358 | BUG_ON(p->se.on_rq); |
48f24c4d | 4359 | |
1da177e4 LT |
4360 | p->policy = policy; |
4361 | p->rt_priority = prio; | |
b29739f9 IM |
4362 | p->normal_prio = normal_prio(p); |
4363 | /* we are holding p->pi_lock already */ | |
4364 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
4365 | if (rt_prio(p->prio)) |
4366 | p->sched_class = &rt_sched_class; | |
4367 | else | |
4368 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 4369 | set_load_weight(p); |
1da177e4 LT |
4370 | } |
4371 | ||
c69e8d9c DH |
4372 | /* |
4373 | * check the target process has a UID that matches the current process's | |
4374 | */ | |
4375 | static bool check_same_owner(struct task_struct *p) | |
4376 | { | |
4377 | const struct cred *cred = current_cred(), *pcred; | |
4378 | bool match; | |
4379 | ||
4380 | rcu_read_lock(); | |
4381 | pcred = __task_cred(p); | |
4382 | match = (cred->euid == pcred->euid || | |
4383 | cred->euid == pcred->uid); | |
4384 | rcu_read_unlock(); | |
4385 | return match; | |
4386 | } | |
4387 | ||
961ccddd RR |
4388 | static int __sched_setscheduler(struct task_struct *p, int policy, |
4389 | struct sched_param *param, bool user) | |
1da177e4 | 4390 | { |
83b699ed | 4391 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 4392 | unsigned long flags; |
83ab0aa0 | 4393 | const struct sched_class *prev_class; |
70b97a7f | 4394 | struct rq *rq; |
ca94c442 | 4395 | int reset_on_fork; |
1da177e4 | 4396 | |
66e5393a SR |
4397 | /* may grab non-irq protected spin_locks */ |
4398 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
4399 | recheck: |
4400 | /* double check policy once rq lock held */ | |
ca94c442 LP |
4401 | if (policy < 0) { |
4402 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 4403 | policy = oldpolicy = p->policy; |
ca94c442 LP |
4404 | } else { |
4405 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
4406 | policy &= ~SCHED_RESET_ON_FORK; | |
4407 | ||
4408 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
4409 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
4410 | policy != SCHED_IDLE) | |
4411 | return -EINVAL; | |
4412 | } | |
4413 | ||
1da177e4 LT |
4414 | /* |
4415 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
4416 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
4417 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
4418 | */ |
4419 | if (param->sched_priority < 0 || | |
95cdf3b7 | 4420 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 4421 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 4422 | return -EINVAL; |
e05606d3 | 4423 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
4424 | return -EINVAL; |
4425 | ||
37e4ab3f OC |
4426 | /* |
4427 | * Allow unprivileged RT tasks to decrease priority: | |
4428 | */ | |
961ccddd | 4429 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 4430 | if (rt_policy(policy)) { |
8dc3e909 | 4431 | unsigned long rlim_rtprio; |
8dc3e909 ON |
4432 | |
4433 | if (!lock_task_sighand(p, &flags)) | |
4434 | return -ESRCH; | |
78d7d407 | 4435 | rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); |
8dc3e909 ON |
4436 | unlock_task_sighand(p, &flags); |
4437 | ||
4438 | /* can't set/change the rt policy */ | |
4439 | if (policy != p->policy && !rlim_rtprio) | |
4440 | return -EPERM; | |
4441 | ||
4442 | /* can't increase priority */ | |
4443 | if (param->sched_priority > p->rt_priority && | |
4444 | param->sched_priority > rlim_rtprio) | |
4445 | return -EPERM; | |
4446 | } | |
dd41f596 IM |
4447 | /* |
4448 | * Like positive nice levels, dont allow tasks to | |
4449 | * move out of SCHED_IDLE either: | |
4450 | */ | |
4451 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
4452 | return -EPERM; | |
5fe1d75f | 4453 | |
37e4ab3f | 4454 | /* can't change other user's priorities */ |
c69e8d9c | 4455 | if (!check_same_owner(p)) |
37e4ab3f | 4456 | return -EPERM; |
ca94c442 LP |
4457 | |
4458 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
4459 | if (p->sched_reset_on_fork && !reset_on_fork) | |
4460 | return -EPERM; | |
37e4ab3f | 4461 | } |
1da177e4 | 4462 | |
725aad24 | 4463 | if (user) { |
b68aa230 | 4464 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
4465 | /* |
4466 | * Do not allow realtime tasks into groups that have no runtime | |
4467 | * assigned. | |
4468 | */ | |
9a7e0b18 PZ |
4469 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
4470 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 4471 | return -EPERM; |
b68aa230 PZ |
4472 | #endif |
4473 | ||
725aad24 JF |
4474 | retval = security_task_setscheduler(p, policy, param); |
4475 | if (retval) | |
4476 | return retval; | |
4477 | } | |
4478 | ||
b29739f9 IM |
4479 | /* |
4480 | * make sure no PI-waiters arrive (or leave) while we are | |
4481 | * changing the priority of the task: | |
4482 | */ | |
1d615482 | 4483 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
1da177e4 LT |
4484 | /* |
4485 | * To be able to change p->policy safely, the apropriate | |
4486 | * runqueue lock must be held. | |
4487 | */ | |
b29739f9 | 4488 | rq = __task_rq_lock(p); |
1da177e4 LT |
4489 | /* recheck policy now with rq lock held */ |
4490 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
4491 | policy = oldpolicy = -1; | |
b29739f9 | 4492 | __task_rq_unlock(rq); |
1d615482 | 4493 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4494 | goto recheck; |
4495 | } | |
dd41f596 | 4496 | on_rq = p->se.on_rq; |
051a1d1a | 4497 | running = task_current(rq, p); |
0e1f3483 | 4498 | if (on_rq) |
2e1cb74a | 4499 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
4500 | if (running) |
4501 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 4502 | |
ca94c442 LP |
4503 | p->sched_reset_on_fork = reset_on_fork; |
4504 | ||
1da177e4 | 4505 | oldprio = p->prio; |
83ab0aa0 | 4506 | prev_class = p->sched_class; |
dd41f596 | 4507 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 4508 | |
0e1f3483 HS |
4509 | if (running) |
4510 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
4511 | if (on_rq) { |
4512 | activate_task(rq, p, 0); | |
cb469845 SR |
4513 | |
4514 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 4515 | } |
b29739f9 | 4516 | __task_rq_unlock(rq); |
1d615482 | 4517 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
b29739f9 | 4518 | |
95e02ca9 TG |
4519 | rt_mutex_adjust_pi(p); |
4520 | ||
1da177e4 LT |
4521 | return 0; |
4522 | } | |
961ccddd RR |
4523 | |
4524 | /** | |
4525 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
4526 | * @p: the task in question. | |
4527 | * @policy: new policy. | |
4528 | * @param: structure containing the new RT priority. | |
4529 | * | |
4530 | * NOTE that the task may be already dead. | |
4531 | */ | |
4532 | int sched_setscheduler(struct task_struct *p, int policy, | |
4533 | struct sched_param *param) | |
4534 | { | |
4535 | return __sched_setscheduler(p, policy, param, true); | |
4536 | } | |
1da177e4 LT |
4537 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
4538 | ||
961ccddd RR |
4539 | /** |
4540 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
4541 | * @p: the task in question. | |
4542 | * @policy: new policy. | |
4543 | * @param: structure containing the new RT priority. | |
4544 | * | |
4545 | * Just like sched_setscheduler, only don't bother checking if the | |
4546 | * current context has permission. For example, this is needed in | |
4547 | * stop_machine(): we create temporary high priority worker threads, | |
4548 | * but our caller might not have that capability. | |
4549 | */ | |
4550 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
4551 | struct sched_param *param) | |
4552 | { | |
4553 | return __sched_setscheduler(p, policy, param, false); | |
4554 | } | |
4555 | ||
95cdf3b7 IM |
4556 | static int |
4557 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 4558 | { |
1da177e4 LT |
4559 | struct sched_param lparam; |
4560 | struct task_struct *p; | |
36c8b586 | 4561 | int retval; |
1da177e4 LT |
4562 | |
4563 | if (!param || pid < 0) | |
4564 | return -EINVAL; | |
4565 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
4566 | return -EFAULT; | |
5fe1d75f ON |
4567 | |
4568 | rcu_read_lock(); | |
4569 | retval = -ESRCH; | |
1da177e4 | 4570 | p = find_process_by_pid(pid); |
5fe1d75f ON |
4571 | if (p != NULL) |
4572 | retval = sched_setscheduler(p, policy, &lparam); | |
4573 | rcu_read_unlock(); | |
36c8b586 | 4574 | |
1da177e4 LT |
4575 | return retval; |
4576 | } | |
4577 | ||
4578 | /** | |
4579 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
4580 | * @pid: the pid in question. | |
4581 | * @policy: new policy. | |
4582 | * @param: structure containing the new RT priority. | |
4583 | */ | |
5add95d4 HC |
4584 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
4585 | struct sched_param __user *, param) | |
1da177e4 | 4586 | { |
c21761f1 JB |
4587 | /* negative values for policy are not valid */ |
4588 | if (policy < 0) | |
4589 | return -EINVAL; | |
4590 | ||
1da177e4 LT |
4591 | return do_sched_setscheduler(pid, policy, param); |
4592 | } | |
4593 | ||
4594 | /** | |
4595 | * sys_sched_setparam - set/change the RT priority of a thread | |
4596 | * @pid: the pid in question. | |
4597 | * @param: structure containing the new RT priority. | |
4598 | */ | |
5add95d4 | 4599 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4600 | { |
4601 | return do_sched_setscheduler(pid, -1, param); | |
4602 | } | |
4603 | ||
4604 | /** | |
4605 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
4606 | * @pid: the pid in question. | |
4607 | */ | |
5add95d4 | 4608 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 4609 | { |
36c8b586 | 4610 | struct task_struct *p; |
3a5c359a | 4611 | int retval; |
1da177e4 LT |
4612 | |
4613 | if (pid < 0) | |
3a5c359a | 4614 | return -EINVAL; |
1da177e4 LT |
4615 | |
4616 | retval = -ESRCH; | |
5fe85be0 | 4617 | rcu_read_lock(); |
1da177e4 LT |
4618 | p = find_process_by_pid(pid); |
4619 | if (p) { | |
4620 | retval = security_task_getscheduler(p); | |
4621 | if (!retval) | |
ca94c442 LP |
4622 | retval = p->policy |
4623 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 4624 | } |
5fe85be0 | 4625 | rcu_read_unlock(); |
1da177e4 LT |
4626 | return retval; |
4627 | } | |
4628 | ||
4629 | /** | |
ca94c442 | 4630 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
4631 | * @pid: the pid in question. |
4632 | * @param: structure containing the RT priority. | |
4633 | */ | |
5add95d4 | 4634 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4635 | { |
4636 | struct sched_param lp; | |
36c8b586 | 4637 | struct task_struct *p; |
3a5c359a | 4638 | int retval; |
1da177e4 LT |
4639 | |
4640 | if (!param || pid < 0) | |
3a5c359a | 4641 | return -EINVAL; |
1da177e4 | 4642 | |
5fe85be0 | 4643 | rcu_read_lock(); |
1da177e4 LT |
4644 | p = find_process_by_pid(pid); |
4645 | retval = -ESRCH; | |
4646 | if (!p) | |
4647 | goto out_unlock; | |
4648 | ||
4649 | retval = security_task_getscheduler(p); | |
4650 | if (retval) | |
4651 | goto out_unlock; | |
4652 | ||
4653 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 4654 | rcu_read_unlock(); |
1da177e4 LT |
4655 | |
4656 | /* | |
4657 | * This one might sleep, we cannot do it with a spinlock held ... | |
4658 | */ | |
4659 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
4660 | ||
1da177e4 LT |
4661 | return retval; |
4662 | ||
4663 | out_unlock: | |
5fe85be0 | 4664 | rcu_read_unlock(); |
1da177e4 LT |
4665 | return retval; |
4666 | } | |
4667 | ||
96f874e2 | 4668 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4669 | { |
5a16f3d3 | 4670 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4671 | struct task_struct *p; |
4672 | int retval; | |
1da177e4 | 4673 | |
95402b38 | 4674 | get_online_cpus(); |
23f5d142 | 4675 | rcu_read_lock(); |
1da177e4 LT |
4676 | |
4677 | p = find_process_by_pid(pid); | |
4678 | if (!p) { | |
23f5d142 | 4679 | rcu_read_unlock(); |
95402b38 | 4680 | put_online_cpus(); |
1da177e4 LT |
4681 | return -ESRCH; |
4682 | } | |
4683 | ||
23f5d142 | 4684 | /* Prevent p going away */ |
1da177e4 | 4685 | get_task_struct(p); |
23f5d142 | 4686 | rcu_read_unlock(); |
1da177e4 | 4687 | |
5a16f3d3 RR |
4688 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4689 | retval = -ENOMEM; | |
4690 | goto out_put_task; | |
4691 | } | |
4692 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4693 | retval = -ENOMEM; | |
4694 | goto out_free_cpus_allowed; | |
4695 | } | |
1da177e4 | 4696 | retval = -EPERM; |
c69e8d9c | 4697 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
4698 | goto out_unlock; |
4699 | ||
e7834f8f DQ |
4700 | retval = security_task_setscheduler(p, 0, NULL); |
4701 | if (retval) | |
4702 | goto out_unlock; | |
4703 | ||
5a16f3d3 RR |
4704 | cpuset_cpus_allowed(p, cpus_allowed); |
4705 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 4706 | again: |
5a16f3d3 | 4707 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4708 | |
8707d8b8 | 4709 | if (!retval) { |
5a16f3d3 RR |
4710 | cpuset_cpus_allowed(p, cpus_allowed); |
4711 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4712 | /* |
4713 | * We must have raced with a concurrent cpuset | |
4714 | * update. Just reset the cpus_allowed to the | |
4715 | * cpuset's cpus_allowed | |
4716 | */ | |
5a16f3d3 | 4717 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4718 | goto again; |
4719 | } | |
4720 | } | |
1da177e4 | 4721 | out_unlock: |
5a16f3d3 RR |
4722 | free_cpumask_var(new_mask); |
4723 | out_free_cpus_allowed: | |
4724 | free_cpumask_var(cpus_allowed); | |
4725 | out_put_task: | |
1da177e4 | 4726 | put_task_struct(p); |
95402b38 | 4727 | put_online_cpus(); |
1da177e4 LT |
4728 | return retval; |
4729 | } | |
4730 | ||
4731 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4732 | struct cpumask *new_mask) |
1da177e4 | 4733 | { |
96f874e2 RR |
4734 | if (len < cpumask_size()) |
4735 | cpumask_clear(new_mask); | |
4736 | else if (len > cpumask_size()) | |
4737 | len = cpumask_size(); | |
4738 | ||
1da177e4 LT |
4739 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4740 | } | |
4741 | ||
4742 | /** | |
4743 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4744 | * @pid: pid of the process | |
4745 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4746 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
4747 | */ | |
5add95d4 HC |
4748 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4749 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4750 | { |
5a16f3d3 | 4751 | cpumask_var_t new_mask; |
1da177e4 LT |
4752 | int retval; |
4753 | ||
5a16f3d3 RR |
4754 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4755 | return -ENOMEM; | |
1da177e4 | 4756 | |
5a16f3d3 RR |
4757 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4758 | if (retval == 0) | |
4759 | retval = sched_setaffinity(pid, new_mask); | |
4760 | free_cpumask_var(new_mask); | |
4761 | return retval; | |
1da177e4 LT |
4762 | } |
4763 | ||
96f874e2 | 4764 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4765 | { |
36c8b586 | 4766 | struct task_struct *p; |
31605683 TG |
4767 | unsigned long flags; |
4768 | struct rq *rq; | |
1da177e4 | 4769 | int retval; |
1da177e4 | 4770 | |
95402b38 | 4771 | get_online_cpus(); |
23f5d142 | 4772 | rcu_read_lock(); |
1da177e4 LT |
4773 | |
4774 | retval = -ESRCH; | |
4775 | p = find_process_by_pid(pid); | |
4776 | if (!p) | |
4777 | goto out_unlock; | |
4778 | ||
e7834f8f DQ |
4779 | retval = security_task_getscheduler(p); |
4780 | if (retval) | |
4781 | goto out_unlock; | |
4782 | ||
31605683 | 4783 | rq = task_rq_lock(p, &flags); |
96f874e2 | 4784 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
31605683 | 4785 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
4786 | |
4787 | out_unlock: | |
23f5d142 | 4788 | rcu_read_unlock(); |
95402b38 | 4789 | put_online_cpus(); |
1da177e4 | 4790 | |
9531b62f | 4791 | return retval; |
1da177e4 LT |
4792 | } |
4793 | ||
4794 | /** | |
4795 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4796 | * @pid: pid of the process | |
4797 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4798 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
4799 | */ | |
5add95d4 HC |
4800 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4801 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4802 | { |
4803 | int ret; | |
f17c8607 | 4804 | cpumask_var_t mask; |
1da177e4 | 4805 | |
84fba5ec | 4806 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4807 | return -EINVAL; |
4808 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4809 | return -EINVAL; |
4810 | ||
f17c8607 RR |
4811 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4812 | return -ENOMEM; | |
1da177e4 | 4813 | |
f17c8607 RR |
4814 | ret = sched_getaffinity(pid, mask); |
4815 | if (ret == 0) { | |
8bc037fb | 4816 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4817 | |
4818 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4819 | ret = -EFAULT; |
4820 | else | |
cd3d8031 | 4821 | ret = retlen; |
f17c8607 RR |
4822 | } |
4823 | free_cpumask_var(mask); | |
1da177e4 | 4824 | |
f17c8607 | 4825 | return ret; |
1da177e4 LT |
4826 | } |
4827 | ||
4828 | /** | |
4829 | * sys_sched_yield - yield the current processor to other threads. | |
4830 | * | |
dd41f596 IM |
4831 | * This function yields the current CPU to other tasks. If there are no |
4832 | * other threads running on this CPU then this function will return. | |
1da177e4 | 4833 | */ |
5add95d4 | 4834 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4835 | { |
70b97a7f | 4836 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4837 | |
2d72376b | 4838 | schedstat_inc(rq, yld_count); |
4530d7ab | 4839 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4840 | |
4841 | /* | |
4842 | * Since we are going to call schedule() anyway, there's | |
4843 | * no need to preempt or enable interrupts: | |
4844 | */ | |
4845 | __release(rq->lock); | |
8a25d5de | 4846 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4847 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
4848 | preempt_enable_no_resched(); |
4849 | ||
4850 | schedule(); | |
4851 | ||
4852 | return 0; | |
4853 | } | |
4854 | ||
d86ee480 PZ |
4855 | static inline int should_resched(void) |
4856 | { | |
4857 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
4858 | } | |
4859 | ||
e7b38404 | 4860 | static void __cond_resched(void) |
1da177e4 | 4861 | { |
e7aaaa69 FW |
4862 | add_preempt_count(PREEMPT_ACTIVE); |
4863 | schedule(); | |
4864 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
4865 | } |
4866 | ||
02b67cc3 | 4867 | int __sched _cond_resched(void) |
1da177e4 | 4868 | { |
d86ee480 | 4869 | if (should_resched()) { |
1da177e4 LT |
4870 | __cond_resched(); |
4871 | return 1; | |
4872 | } | |
4873 | return 0; | |
4874 | } | |
02b67cc3 | 4875 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4876 | |
4877 | /* | |
613afbf8 | 4878 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4879 | * call schedule, and on return reacquire the lock. |
4880 | * | |
41a2d6cf | 4881 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4882 | * operations here to prevent schedule() from being called twice (once via |
4883 | * spin_unlock(), once by hand). | |
4884 | */ | |
613afbf8 | 4885 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4886 | { |
d86ee480 | 4887 | int resched = should_resched(); |
6df3cecb JK |
4888 | int ret = 0; |
4889 | ||
f607c668 PZ |
4890 | lockdep_assert_held(lock); |
4891 | ||
95c354fe | 4892 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 4893 | spin_unlock(lock); |
d86ee480 | 4894 | if (resched) |
95c354fe NP |
4895 | __cond_resched(); |
4896 | else | |
4897 | cpu_relax(); | |
6df3cecb | 4898 | ret = 1; |
1da177e4 | 4899 | spin_lock(lock); |
1da177e4 | 4900 | } |
6df3cecb | 4901 | return ret; |
1da177e4 | 4902 | } |
613afbf8 | 4903 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4904 | |
613afbf8 | 4905 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4906 | { |
4907 | BUG_ON(!in_softirq()); | |
4908 | ||
d86ee480 | 4909 | if (should_resched()) { |
98d82567 | 4910 | local_bh_enable(); |
1da177e4 LT |
4911 | __cond_resched(); |
4912 | local_bh_disable(); | |
4913 | return 1; | |
4914 | } | |
4915 | return 0; | |
4916 | } | |
613afbf8 | 4917 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4918 | |
1da177e4 LT |
4919 | /** |
4920 | * yield - yield the current processor to other threads. | |
4921 | * | |
72fd4a35 | 4922 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
4923 | * thread runnable and calls sys_sched_yield(). |
4924 | */ | |
4925 | void __sched yield(void) | |
4926 | { | |
4927 | set_current_state(TASK_RUNNING); | |
4928 | sys_sched_yield(); | |
4929 | } | |
1da177e4 LT |
4930 | EXPORT_SYMBOL(yield); |
4931 | ||
4932 | /* | |
41a2d6cf | 4933 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4934 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4935 | */ |
4936 | void __sched io_schedule(void) | |
4937 | { | |
54d35f29 | 4938 | struct rq *rq = raw_rq(); |
1da177e4 | 4939 | |
0ff92245 | 4940 | delayacct_blkio_start(); |
1da177e4 | 4941 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 4942 | current->in_iowait = 1; |
1da177e4 | 4943 | schedule(); |
8f0dfc34 | 4944 | current->in_iowait = 0; |
1da177e4 | 4945 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4946 | delayacct_blkio_end(); |
1da177e4 | 4947 | } |
1da177e4 LT |
4948 | EXPORT_SYMBOL(io_schedule); |
4949 | ||
4950 | long __sched io_schedule_timeout(long timeout) | |
4951 | { | |
54d35f29 | 4952 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4953 | long ret; |
4954 | ||
0ff92245 | 4955 | delayacct_blkio_start(); |
1da177e4 | 4956 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 4957 | current->in_iowait = 1; |
1da177e4 | 4958 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4959 | current->in_iowait = 0; |
1da177e4 | 4960 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4961 | delayacct_blkio_end(); |
1da177e4 LT |
4962 | return ret; |
4963 | } | |
4964 | ||
4965 | /** | |
4966 | * sys_sched_get_priority_max - return maximum RT priority. | |
4967 | * @policy: scheduling class. | |
4968 | * | |
4969 | * this syscall returns the maximum rt_priority that can be used | |
4970 | * by a given scheduling class. | |
4971 | */ | |
5add95d4 | 4972 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4973 | { |
4974 | int ret = -EINVAL; | |
4975 | ||
4976 | switch (policy) { | |
4977 | case SCHED_FIFO: | |
4978 | case SCHED_RR: | |
4979 | ret = MAX_USER_RT_PRIO-1; | |
4980 | break; | |
4981 | case SCHED_NORMAL: | |
b0a9499c | 4982 | case SCHED_BATCH: |
dd41f596 | 4983 | case SCHED_IDLE: |
1da177e4 LT |
4984 | ret = 0; |
4985 | break; | |
4986 | } | |
4987 | return ret; | |
4988 | } | |
4989 | ||
4990 | /** | |
4991 | * sys_sched_get_priority_min - return minimum RT priority. | |
4992 | * @policy: scheduling class. | |
4993 | * | |
4994 | * this syscall returns the minimum rt_priority that can be used | |
4995 | * by a given scheduling class. | |
4996 | */ | |
5add95d4 | 4997 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
4998 | { |
4999 | int ret = -EINVAL; | |
5000 | ||
5001 | switch (policy) { | |
5002 | case SCHED_FIFO: | |
5003 | case SCHED_RR: | |
5004 | ret = 1; | |
5005 | break; | |
5006 | case SCHED_NORMAL: | |
b0a9499c | 5007 | case SCHED_BATCH: |
dd41f596 | 5008 | case SCHED_IDLE: |
1da177e4 LT |
5009 | ret = 0; |
5010 | } | |
5011 | return ret; | |
5012 | } | |
5013 | ||
5014 | /** | |
5015 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5016 | * @pid: pid of the process. | |
5017 | * @interval: userspace pointer to the timeslice value. | |
5018 | * | |
5019 | * this syscall writes the default timeslice value of a given process | |
5020 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5021 | */ | |
17da2bd9 | 5022 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5023 | struct timespec __user *, interval) |
1da177e4 | 5024 | { |
36c8b586 | 5025 | struct task_struct *p; |
a4ec24b4 | 5026 | unsigned int time_slice; |
dba091b9 TG |
5027 | unsigned long flags; |
5028 | struct rq *rq; | |
3a5c359a | 5029 | int retval; |
1da177e4 | 5030 | struct timespec t; |
1da177e4 LT |
5031 | |
5032 | if (pid < 0) | |
3a5c359a | 5033 | return -EINVAL; |
1da177e4 LT |
5034 | |
5035 | retval = -ESRCH; | |
1a551ae7 | 5036 | rcu_read_lock(); |
1da177e4 LT |
5037 | p = find_process_by_pid(pid); |
5038 | if (!p) | |
5039 | goto out_unlock; | |
5040 | ||
5041 | retval = security_task_getscheduler(p); | |
5042 | if (retval) | |
5043 | goto out_unlock; | |
5044 | ||
dba091b9 TG |
5045 | rq = task_rq_lock(p, &flags); |
5046 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
5047 | task_rq_unlock(rq, &flags); | |
a4ec24b4 | 5048 | |
1a551ae7 | 5049 | rcu_read_unlock(); |
a4ec24b4 | 5050 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5051 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5052 | return retval; |
3a5c359a | 5053 | |
1da177e4 | 5054 | out_unlock: |
1a551ae7 | 5055 | rcu_read_unlock(); |
1da177e4 LT |
5056 | return retval; |
5057 | } | |
5058 | ||
7c731e0a | 5059 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5060 | |
82a1fcb9 | 5061 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5062 | { |
1da177e4 | 5063 | unsigned long free = 0; |
36c8b586 | 5064 | unsigned state; |
1da177e4 | 5065 | |
1da177e4 | 5066 | state = p->state ? __ffs(p->state) + 1 : 0; |
3df0fc5b | 5067 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 5068 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5069 | #if BITS_PER_LONG == 32 |
1da177e4 | 5070 | if (state == TASK_RUNNING) |
3df0fc5b | 5071 | printk(KERN_CONT " running "); |
1da177e4 | 5072 | else |
3df0fc5b | 5073 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5074 | #else |
5075 | if (state == TASK_RUNNING) | |
3df0fc5b | 5076 | printk(KERN_CONT " running task "); |
1da177e4 | 5077 | else |
3df0fc5b | 5078 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
5079 | #endif |
5080 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 5081 | free = stack_not_used(p); |
1da177e4 | 5082 | #endif |
3df0fc5b | 5083 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
5084 | task_pid_nr(p), task_pid_nr(p->real_parent), |
5085 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 5086 | |
5fb5e6de | 5087 | show_stack(p, NULL); |
1da177e4 LT |
5088 | } |
5089 | ||
e59e2ae2 | 5090 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 5091 | { |
36c8b586 | 5092 | struct task_struct *g, *p; |
1da177e4 | 5093 | |
4bd77321 | 5094 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
5095 | printk(KERN_INFO |
5096 | " task PC stack pid father\n"); | |
1da177e4 | 5097 | #else |
3df0fc5b PZ |
5098 | printk(KERN_INFO |
5099 | " task PC stack pid father\n"); | |
1da177e4 LT |
5100 | #endif |
5101 | read_lock(&tasklist_lock); | |
5102 | do_each_thread(g, p) { | |
5103 | /* | |
5104 | * reset the NMI-timeout, listing all files on a slow | |
5105 | * console might take alot of time: | |
5106 | */ | |
5107 | touch_nmi_watchdog(); | |
39bc89fd | 5108 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 5109 | sched_show_task(p); |
1da177e4 LT |
5110 | } while_each_thread(g, p); |
5111 | ||
04c9167f JF |
5112 | touch_all_softlockup_watchdogs(); |
5113 | ||
dd41f596 IM |
5114 | #ifdef CONFIG_SCHED_DEBUG |
5115 | sysrq_sched_debug_show(); | |
5116 | #endif | |
1da177e4 | 5117 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
5118 | /* |
5119 | * Only show locks if all tasks are dumped: | |
5120 | */ | |
93335a21 | 5121 | if (!state_filter) |
e59e2ae2 | 5122 | debug_show_all_locks(); |
1da177e4 LT |
5123 | } |
5124 | ||
1df21055 IM |
5125 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
5126 | { | |
dd41f596 | 5127 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
5128 | } |
5129 | ||
f340c0d1 IM |
5130 | /** |
5131 | * init_idle - set up an idle thread for a given CPU | |
5132 | * @idle: task in question | |
5133 | * @cpu: cpu the idle task belongs to | |
5134 | * | |
5135 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
5136 | * flag, to make booting more robust. | |
5137 | */ | |
5c1e1767 | 5138 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 5139 | { |
70b97a7f | 5140 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5141 | unsigned long flags; |
5142 | ||
05fa785c | 5143 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 5144 | |
dd41f596 | 5145 | __sched_fork(idle); |
06b83b5f | 5146 | idle->state = TASK_RUNNING; |
dd41f596 IM |
5147 | idle->se.exec_start = sched_clock(); |
5148 | ||
96f874e2 | 5149 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 5150 | __set_task_cpu(idle, cpu); |
1da177e4 | 5151 | |
1da177e4 | 5152 | rq->curr = rq->idle = idle; |
4866cde0 NP |
5153 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
5154 | idle->oncpu = 1; | |
5155 | #endif | |
05fa785c | 5156 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5157 | |
5158 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
5159 | #if defined(CONFIG_PREEMPT) |
5160 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
5161 | #else | |
a1261f54 | 5162 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 5163 | #endif |
dd41f596 IM |
5164 | /* |
5165 | * The idle tasks have their own, simple scheduling class: | |
5166 | */ | |
5167 | idle->sched_class = &idle_sched_class; | |
fb52607a | 5168 | ftrace_graph_init_task(idle); |
1da177e4 LT |
5169 | } |
5170 | ||
5171 | /* | |
5172 | * In a system that switches off the HZ timer nohz_cpu_mask | |
5173 | * indicates which cpus entered this state. This is used | |
5174 | * in the rcu update to wait only for active cpus. For system | |
5175 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 5176 | * always be CPU_BITS_NONE. |
1da177e4 | 5177 | */ |
6a7b3dc3 | 5178 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 5179 | |
19978ca6 IM |
5180 | /* |
5181 | * Increase the granularity value when there are more CPUs, | |
5182 | * because with more CPUs the 'effective latency' as visible | |
5183 | * to users decreases. But the relationship is not linear, | |
5184 | * so pick a second-best guess by going with the log2 of the | |
5185 | * number of CPUs. | |
5186 | * | |
5187 | * This idea comes from the SD scheduler of Con Kolivas: | |
5188 | */ | |
acb4a848 | 5189 | static int get_update_sysctl_factor(void) |
19978ca6 | 5190 | { |
4ca3ef71 | 5191 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
5192 | unsigned int factor; |
5193 | ||
5194 | switch (sysctl_sched_tunable_scaling) { | |
5195 | case SCHED_TUNABLESCALING_NONE: | |
5196 | factor = 1; | |
5197 | break; | |
5198 | case SCHED_TUNABLESCALING_LINEAR: | |
5199 | factor = cpus; | |
5200 | break; | |
5201 | case SCHED_TUNABLESCALING_LOG: | |
5202 | default: | |
5203 | factor = 1 + ilog2(cpus); | |
5204 | break; | |
5205 | } | |
19978ca6 | 5206 | |
acb4a848 CE |
5207 | return factor; |
5208 | } | |
19978ca6 | 5209 | |
acb4a848 CE |
5210 | static void update_sysctl(void) |
5211 | { | |
5212 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 5213 | |
0bcdcf28 CE |
5214 | #define SET_SYSCTL(name) \ |
5215 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
5216 | SET_SYSCTL(sched_min_granularity); | |
5217 | SET_SYSCTL(sched_latency); | |
5218 | SET_SYSCTL(sched_wakeup_granularity); | |
5219 | SET_SYSCTL(sched_shares_ratelimit); | |
5220 | #undef SET_SYSCTL | |
5221 | } | |
55cd5340 | 5222 | |
0bcdcf28 CE |
5223 | static inline void sched_init_granularity(void) |
5224 | { | |
5225 | update_sysctl(); | |
19978ca6 IM |
5226 | } |
5227 | ||
1da177e4 LT |
5228 | #ifdef CONFIG_SMP |
5229 | /* | |
5230 | * This is how migration works: | |
5231 | * | |
969c7921 TH |
5232 | * 1) we invoke migration_cpu_stop() on the target CPU using |
5233 | * stop_one_cpu(). | |
5234 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
5235 | * off the CPU) | |
5236 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
5237 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 5238 | * it and puts it into the right queue. |
969c7921 TH |
5239 | * 5) stopper completes and stop_one_cpu() returns and the migration |
5240 | * is done. | |
1da177e4 LT |
5241 | */ |
5242 | ||
5243 | /* | |
5244 | * Change a given task's CPU affinity. Migrate the thread to a | |
5245 | * proper CPU and schedule it away if the CPU it's executing on | |
5246 | * is removed from the allowed bitmask. | |
5247 | * | |
5248 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 5249 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
5250 | * call is not atomic; no spinlocks may be held. |
5251 | */ | |
96f874e2 | 5252 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
5253 | { |
5254 | unsigned long flags; | |
70b97a7f | 5255 | struct rq *rq; |
969c7921 | 5256 | unsigned int dest_cpu; |
48f24c4d | 5257 | int ret = 0; |
1da177e4 | 5258 | |
65cc8e48 PZ |
5259 | /* |
5260 | * Serialize against TASK_WAKING so that ttwu() and wunt() can | |
5261 | * drop the rq->lock and still rely on ->cpus_allowed. | |
5262 | */ | |
5263 | again: | |
5264 | while (task_is_waking(p)) | |
5265 | cpu_relax(); | |
1da177e4 | 5266 | rq = task_rq_lock(p, &flags); |
65cc8e48 PZ |
5267 | if (task_is_waking(p)) { |
5268 | task_rq_unlock(rq, &flags); | |
5269 | goto again; | |
5270 | } | |
e2912009 | 5271 | |
6ad4c188 | 5272 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
5273 | ret = -EINVAL; |
5274 | goto out; | |
5275 | } | |
5276 | ||
9985b0ba | 5277 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 5278 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
5279 | ret = -EINVAL; |
5280 | goto out; | |
5281 | } | |
5282 | ||
73fe6aae | 5283 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 5284 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 5285 | else { |
96f874e2 RR |
5286 | cpumask_copy(&p->cpus_allowed, new_mask); |
5287 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
5288 | } |
5289 | ||
1da177e4 | 5290 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 5291 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
5292 | goto out; |
5293 | ||
969c7921 TH |
5294 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
5295 | if (migrate_task(p, dest_cpu)) { | |
5296 | struct migration_arg arg = { p, dest_cpu }; | |
1da177e4 LT |
5297 | /* Need help from migration thread: drop lock and wait. */ |
5298 | task_rq_unlock(rq, &flags); | |
969c7921 | 5299 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
5300 | tlb_migrate_finish(p->mm); |
5301 | return 0; | |
5302 | } | |
5303 | out: | |
5304 | task_rq_unlock(rq, &flags); | |
48f24c4d | 5305 | |
1da177e4 LT |
5306 | return ret; |
5307 | } | |
cd8ba7cd | 5308 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
5309 | |
5310 | /* | |
41a2d6cf | 5311 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
5312 | * this because either it can't run here any more (set_cpus_allowed() |
5313 | * away from this CPU, or CPU going down), or because we're | |
5314 | * attempting to rebalance this task on exec (sched_exec). | |
5315 | * | |
5316 | * So we race with normal scheduler movements, but that's OK, as long | |
5317 | * as the task is no longer on this CPU. | |
efc30814 KK |
5318 | * |
5319 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 5320 | */ |
efc30814 | 5321 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 5322 | { |
70b97a7f | 5323 | struct rq *rq_dest, *rq_src; |
e2912009 | 5324 | int ret = 0; |
1da177e4 | 5325 | |
e761b772 | 5326 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 5327 | return ret; |
1da177e4 LT |
5328 | |
5329 | rq_src = cpu_rq(src_cpu); | |
5330 | rq_dest = cpu_rq(dest_cpu); | |
5331 | ||
5332 | double_rq_lock(rq_src, rq_dest); | |
5333 | /* Already moved. */ | |
5334 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 5335 | goto done; |
1da177e4 | 5336 | /* Affinity changed (again). */ |
96f874e2 | 5337 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 5338 | goto fail; |
1da177e4 | 5339 | |
e2912009 PZ |
5340 | /* |
5341 | * If we're not on a rq, the next wake-up will ensure we're | |
5342 | * placed properly. | |
5343 | */ | |
5344 | if (p->se.on_rq) { | |
2e1cb74a | 5345 | deactivate_task(rq_src, p, 0); |
e2912009 | 5346 | set_task_cpu(p, dest_cpu); |
dd41f596 | 5347 | activate_task(rq_dest, p, 0); |
15afe09b | 5348 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 5349 | } |
b1e38734 | 5350 | done: |
efc30814 | 5351 | ret = 1; |
b1e38734 | 5352 | fail: |
1da177e4 | 5353 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 5354 | return ret; |
1da177e4 LT |
5355 | } |
5356 | ||
5357 | /* | |
969c7921 TH |
5358 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
5359 | * and performs thread migration by bumping thread off CPU then | |
5360 | * 'pushing' onto another runqueue. | |
1da177e4 | 5361 | */ |
969c7921 | 5362 | static int migration_cpu_stop(void *data) |
1da177e4 | 5363 | { |
969c7921 | 5364 | struct migration_arg *arg = data; |
f7b4cddc | 5365 | |
969c7921 TH |
5366 | /* |
5367 | * The original target cpu might have gone down and we might | |
5368 | * be on another cpu but it doesn't matter. | |
5369 | */ | |
f7b4cddc | 5370 | local_irq_disable(); |
969c7921 | 5371 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 5372 | local_irq_enable(); |
1da177e4 | 5373 | return 0; |
f7b4cddc ON |
5374 | } |
5375 | ||
1da177e4 | 5376 | #ifdef CONFIG_HOTPLUG_CPU |
054b9108 | 5377 | /* |
3a4fa0a2 | 5378 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 5379 | */ |
6a1bdc1b | 5380 | void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 5381 | { |
1445c08d ON |
5382 | struct rq *rq = cpu_rq(dead_cpu); |
5383 | int needs_cpu, uninitialized_var(dest_cpu); | |
5384 | unsigned long flags; | |
e76bd8d9 | 5385 | |
1445c08d | 5386 | local_irq_save(flags); |
e76bd8d9 | 5387 | |
1445c08d ON |
5388 | raw_spin_lock(&rq->lock); |
5389 | needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING); | |
5390 | if (needs_cpu) | |
5391 | dest_cpu = select_fallback_rq(dead_cpu, p); | |
5392 | raw_spin_unlock(&rq->lock); | |
c1804d54 ON |
5393 | /* |
5394 | * It can only fail if we race with set_cpus_allowed(), | |
5395 | * in the racer should migrate the task anyway. | |
5396 | */ | |
1445c08d | 5397 | if (needs_cpu) |
c1804d54 | 5398 | __migrate_task(p, dead_cpu, dest_cpu); |
1445c08d | 5399 | local_irq_restore(flags); |
1da177e4 LT |
5400 | } |
5401 | ||
5402 | /* | |
5403 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
5404 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
5405 | * for performance reasons the counter is not stricly tracking tasks to | |
5406 | * their home CPUs. So we just add the counter to another CPU's counter, | |
5407 | * to keep the global sum constant after CPU-down: | |
5408 | */ | |
70b97a7f | 5409 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 5410 | { |
6ad4c188 | 5411 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 LT |
5412 | unsigned long flags; |
5413 | ||
5414 | local_irq_save(flags); | |
5415 | double_rq_lock(rq_src, rq_dest); | |
5416 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
5417 | rq_src->nr_uninterruptible = 0; | |
5418 | double_rq_unlock(rq_src, rq_dest); | |
5419 | local_irq_restore(flags); | |
5420 | } | |
5421 | ||
5422 | /* Run through task list and migrate tasks from the dead cpu. */ | |
5423 | static void migrate_live_tasks(int src_cpu) | |
5424 | { | |
48f24c4d | 5425 | struct task_struct *p, *t; |
1da177e4 | 5426 | |
f7b4cddc | 5427 | read_lock(&tasklist_lock); |
1da177e4 | 5428 | |
48f24c4d IM |
5429 | do_each_thread(t, p) { |
5430 | if (p == current) | |
1da177e4 LT |
5431 | continue; |
5432 | ||
48f24c4d IM |
5433 | if (task_cpu(p) == src_cpu) |
5434 | move_task_off_dead_cpu(src_cpu, p); | |
5435 | } while_each_thread(t, p); | |
1da177e4 | 5436 | |
f7b4cddc | 5437 | read_unlock(&tasklist_lock); |
1da177e4 LT |
5438 | } |
5439 | ||
dd41f596 IM |
5440 | /* |
5441 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
5442 | * It does so by boosting its priority to highest possible. |
5443 | * Used by CPU offline code. | |
1da177e4 LT |
5444 | */ |
5445 | void sched_idle_next(void) | |
5446 | { | |
48f24c4d | 5447 | int this_cpu = smp_processor_id(); |
70b97a7f | 5448 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
5449 | struct task_struct *p = rq->idle; |
5450 | unsigned long flags; | |
5451 | ||
5452 | /* cpu has to be offline */ | |
48f24c4d | 5453 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 5454 | |
48f24c4d IM |
5455 | /* |
5456 | * Strictly not necessary since rest of the CPUs are stopped by now | |
5457 | * and interrupts disabled on the current cpu. | |
1da177e4 | 5458 | */ |
05fa785c | 5459 | raw_spin_lock_irqsave(&rq->lock, flags); |
1da177e4 | 5460 | |
dd41f596 | 5461 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 5462 | |
94bc9a7b | 5463 | activate_task(rq, p, 0); |
1da177e4 | 5464 | |
05fa785c | 5465 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5466 | } |
5467 | ||
48f24c4d IM |
5468 | /* |
5469 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
5470 | * offline. |
5471 | */ | |
5472 | void idle_task_exit(void) | |
5473 | { | |
5474 | struct mm_struct *mm = current->active_mm; | |
5475 | ||
5476 | BUG_ON(cpu_online(smp_processor_id())); | |
5477 | ||
5478 | if (mm != &init_mm) | |
5479 | switch_mm(mm, &init_mm, current); | |
5480 | mmdrop(mm); | |
5481 | } | |
5482 | ||
054b9108 | 5483 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 5484 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 5485 | { |
70b97a7f | 5486 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
5487 | |
5488 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 5489 | BUG_ON(!p->exit_state); |
1da177e4 LT |
5490 | |
5491 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 5492 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 5493 | |
48f24c4d | 5494 | get_task_struct(p); |
1da177e4 LT |
5495 | |
5496 | /* | |
5497 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 5498 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
5499 | * fine. |
5500 | */ | |
05fa785c | 5501 | raw_spin_unlock_irq(&rq->lock); |
48f24c4d | 5502 | move_task_off_dead_cpu(dead_cpu, p); |
05fa785c | 5503 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5504 | |
48f24c4d | 5505 | put_task_struct(p); |
1da177e4 LT |
5506 | } |
5507 | ||
5508 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
5509 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
5510 | { | |
70b97a7f | 5511 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 5512 | struct task_struct *next; |
48f24c4d | 5513 | |
dd41f596 IM |
5514 | for ( ; ; ) { |
5515 | if (!rq->nr_running) | |
5516 | break; | |
b67802ea | 5517 | next = pick_next_task(rq); |
dd41f596 IM |
5518 | if (!next) |
5519 | break; | |
79c53799 | 5520 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 5521 | migrate_dead(dead_cpu, next); |
e692ab53 | 5522 | |
1da177e4 LT |
5523 | } |
5524 | } | |
dce48a84 TG |
5525 | |
5526 | /* | |
5527 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
5528 | */ | |
5529 | static void calc_global_load_remove(struct rq *rq) | |
5530 | { | |
5531 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 5532 | rq->calc_load_active = 0; |
dce48a84 | 5533 | } |
1da177e4 LT |
5534 | #endif /* CONFIG_HOTPLUG_CPU */ |
5535 | ||
e692ab53 NP |
5536 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
5537 | ||
5538 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
5539 | { |
5540 | .procname = "sched_domain", | |
c57baf1e | 5541 | .mode = 0555, |
e0361851 | 5542 | }, |
56992309 | 5543 | {} |
e692ab53 NP |
5544 | }; |
5545 | ||
5546 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
5547 | { |
5548 | .procname = "kernel", | |
c57baf1e | 5549 | .mode = 0555, |
e0361851 AD |
5550 | .child = sd_ctl_dir, |
5551 | }, | |
56992309 | 5552 | {} |
e692ab53 NP |
5553 | }; |
5554 | ||
5555 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
5556 | { | |
5557 | struct ctl_table *entry = | |
5cf9f062 | 5558 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 5559 | |
e692ab53 NP |
5560 | return entry; |
5561 | } | |
5562 | ||
6382bc90 MM |
5563 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
5564 | { | |
cd790076 | 5565 | struct ctl_table *entry; |
6382bc90 | 5566 | |
cd790076 MM |
5567 | /* |
5568 | * In the intermediate directories, both the child directory and | |
5569 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 5570 | * will always be set. In the lowest directory the names are |
cd790076 MM |
5571 | * static strings and all have proc handlers. |
5572 | */ | |
5573 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
5574 | if (entry->child) |
5575 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
5576 | if (entry->proc_handler == NULL) |
5577 | kfree(entry->procname); | |
5578 | } | |
6382bc90 MM |
5579 | |
5580 | kfree(*tablep); | |
5581 | *tablep = NULL; | |
5582 | } | |
5583 | ||
e692ab53 | 5584 | static void |
e0361851 | 5585 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
5586 | const char *procname, void *data, int maxlen, |
5587 | mode_t mode, proc_handler *proc_handler) | |
5588 | { | |
e692ab53 NP |
5589 | entry->procname = procname; |
5590 | entry->data = data; | |
5591 | entry->maxlen = maxlen; | |
5592 | entry->mode = mode; | |
5593 | entry->proc_handler = proc_handler; | |
5594 | } | |
5595 | ||
5596 | static struct ctl_table * | |
5597 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
5598 | { | |
a5d8c348 | 5599 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 5600 | |
ad1cdc1d MM |
5601 | if (table == NULL) |
5602 | return NULL; | |
5603 | ||
e0361851 | 5604 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 5605 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5606 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 5607 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5608 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 5609 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5610 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 5611 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5612 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 5613 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5614 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 5615 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5616 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 5617 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5618 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 5619 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5620 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 5621 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 5622 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
5623 | &sd->cache_nice_tries, |
5624 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 5625 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 5626 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
5627 | set_table_entry(&table[11], "name", sd->name, |
5628 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
5629 | /* &table[12] is terminator */ | |
e692ab53 NP |
5630 | |
5631 | return table; | |
5632 | } | |
5633 | ||
9a4e7159 | 5634 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
5635 | { |
5636 | struct ctl_table *entry, *table; | |
5637 | struct sched_domain *sd; | |
5638 | int domain_num = 0, i; | |
5639 | char buf[32]; | |
5640 | ||
5641 | for_each_domain(cpu, sd) | |
5642 | domain_num++; | |
5643 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5644 | if (table == NULL) |
5645 | return NULL; | |
e692ab53 NP |
5646 | |
5647 | i = 0; | |
5648 | for_each_domain(cpu, sd) { | |
5649 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5650 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5651 | entry->mode = 0555; |
e692ab53 NP |
5652 | entry->child = sd_alloc_ctl_domain_table(sd); |
5653 | entry++; | |
5654 | i++; | |
5655 | } | |
5656 | return table; | |
5657 | } | |
5658 | ||
5659 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5660 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5661 | { |
6ad4c188 | 5662 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5663 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5664 | char buf[32]; | |
5665 | ||
7378547f MM |
5666 | WARN_ON(sd_ctl_dir[0].child); |
5667 | sd_ctl_dir[0].child = entry; | |
5668 | ||
ad1cdc1d MM |
5669 | if (entry == NULL) |
5670 | return; | |
5671 | ||
6ad4c188 | 5672 | for_each_possible_cpu(i) { |
e692ab53 | 5673 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5674 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5675 | entry->mode = 0555; |
e692ab53 | 5676 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5677 | entry++; |
e692ab53 | 5678 | } |
7378547f MM |
5679 | |
5680 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5681 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5682 | } | |
6382bc90 | 5683 | |
7378547f | 5684 | /* may be called multiple times per register */ |
6382bc90 MM |
5685 | static void unregister_sched_domain_sysctl(void) |
5686 | { | |
7378547f MM |
5687 | if (sd_sysctl_header) |
5688 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5689 | sd_sysctl_header = NULL; |
7378547f MM |
5690 | if (sd_ctl_dir[0].child) |
5691 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5692 | } |
e692ab53 | 5693 | #else |
6382bc90 MM |
5694 | static void register_sched_domain_sysctl(void) |
5695 | { | |
5696 | } | |
5697 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5698 | { |
5699 | } | |
5700 | #endif | |
5701 | ||
1f11eb6a GH |
5702 | static void set_rq_online(struct rq *rq) |
5703 | { | |
5704 | if (!rq->online) { | |
5705 | const struct sched_class *class; | |
5706 | ||
c6c4927b | 5707 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5708 | rq->online = 1; |
5709 | ||
5710 | for_each_class(class) { | |
5711 | if (class->rq_online) | |
5712 | class->rq_online(rq); | |
5713 | } | |
5714 | } | |
5715 | } | |
5716 | ||
5717 | static void set_rq_offline(struct rq *rq) | |
5718 | { | |
5719 | if (rq->online) { | |
5720 | const struct sched_class *class; | |
5721 | ||
5722 | for_each_class(class) { | |
5723 | if (class->rq_offline) | |
5724 | class->rq_offline(rq); | |
5725 | } | |
5726 | ||
c6c4927b | 5727 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5728 | rq->online = 0; |
5729 | } | |
5730 | } | |
5731 | ||
1da177e4 LT |
5732 | /* |
5733 | * migration_call - callback that gets triggered when a CPU is added. | |
5734 | * Here we can start up the necessary migration thread for the new CPU. | |
5735 | */ | |
48f24c4d IM |
5736 | static int __cpuinit |
5737 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 5738 | { |
48f24c4d | 5739 | int cpu = (long)hcpu; |
1da177e4 | 5740 | unsigned long flags; |
969c7921 | 5741 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5742 | |
5743 | switch (action) { | |
5be9361c | 5744 | |
1da177e4 | 5745 | case CPU_UP_PREPARE: |
8bb78442 | 5746 | case CPU_UP_PREPARE_FROZEN: |
a468d389 | 5747 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5748 | break; |
48f24c4d | 5749 | |
1da177e4 | 5750 | case CPU_ONLINE: |
8bb78442 | 5751 | case CPU_ONLINE_FROZEN: |
1f94ef59 | 5752 | /* Update our root-domain */ |
05fa785c | 5753 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5754 | if (rq->rd) { |
c6c4927b | 5755 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5756 | |
5757 | set_rq_online(rq); | |
1f94ef59 | 5758 | } |
05fa785c | 5759 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5760 | break; |
48f24c4d | 5761 | |
1da177e4 | 5762 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 5763 | case CPU_DEAD: |
8bb78442 | 5764 | case CPU_DEAD_FROZEN: |
1da177e4 | 5765 | migrate_live_tasks(cpu); |
1da177e4 | 5766 | /* Idle task back to normal (off runqueue, low prio) */ |
05fa785c | 5767 | raw_spin_lock_irq(&rq->lock); |
2e1cb74a | 5768 | deactivate_task(rq, rq->idle, 0); |
dd41f596 IM |
5769 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
5770 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 5771 | migrate_dead_tasks(cpu); |
05fa785c | 5772 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
5773 | migrate_nr_uninterruptible(rq); |
5774 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 5775 | calc_global_load_remove(rq); |
1da177e4 | 5776 | break; |
57d885fe | 5777 | |
08f503b0 GH |
5778 | case CPU_DYING: |
5779 | case CPU_DYING_FROZEN: | |
57d885fe | 5780 | /* Update our root-domain */ |
05fa785c | 5781 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5782 | if (rq->rd) { |
c6c4927b | 5783 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5784 | set_rq_offline(rq); |
57d885fe | 5785 | } |
05fa785c | 5786 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
57d885fe | 5787 | break; |
1da177e4 LT |
5788 | #endif |
5789 | } | |
5790 | return NOTIFY_OK; | |
5791 | } | |
5792 | ||
f38b0820 PM |
5793 | /* |
5794 | * Register at high priority so that task migration (migrate_all_tasks) | |
5795 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5796 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5797 | */ |
26c2143b | 5798 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
5799 | .notifier_call = migration_call, |
5800 | .priority = 10 | |
5801 | }; | |
5802 | ||
7babe8db | 5803 | static int __init migration_init(void) |
1da177e4 LT |
5804 | { |
5805 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5806 | int err; |
48f24c4d IM |
5807 | |
5808 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
5809 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5810 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5811 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5812 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5813 | |
a004cd42 | 5814 | return 0; |
1da177e4 | 5815 | } |
7babe8db | 5816 | early_initcall(migration_init); |
1da177e4 LT |
5817 | #endif |
5818 | ||
5819 | #ifdef CONFIG_SMP | |
476f3534 | 5820 | |
3e9830dc | 5821 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5822 | |
f6630114 MT |
5823 | static __read_mostly int sched_domain_debug_enabled; |
5824 | ||
5825 | static int __init sched_domain_debug_setup(char *str) | |
5826 | { | |
5827 | sched_domain_debug_enabled = 1; | |
5828 | ||
5829 | return 0; | |
5830 | } | |
5831 | early_param("sched_debug", sched_domain_debug_setup); | |
5832 | ||
7c16ec58 | 5833 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5834 | struct cpumask *groupmask) |
1da177e4 | 5835 | { |
4dcf6aff | 5836 | struct sched_group *group = sd->groups; |
434d53b0 | 5837 | char str[256]; |
1da177e4 | 5838 | |
968ea6d8 | 5839 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5840 | cpumask_clear(groupmask); |
4dcf6aff IM |
5841 | |
5842 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5843 | ||
5844 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5845 | printk("does not load-balance\n"); |
4dcf6aff | 5846 | if (sd->parent) |
3df0fc5b PZ |
5847 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5848 | " has parent"); | |
4dcf6aff | 5849 | return -1; |
41c7ce9a NP |
5850 | } |
5851 | ||
3df0fc5b | 5852 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5853 | |
758b2cdc | 5854 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5855 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5856 | "CPU%d\n", cpu); | |
4dcf6aff | 5857 | } |
758b2cdc | 5858 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5859 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5860 | " CPU%d\n", cpu); | |
4dcf6aff | 5861 | } |
1da177e4 | 5862 | |
4dcf6aff | 5863 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5864 | do { |
4dcf6aff | 5865 | if (!group) { |
3df0fc5b PZ |
5866 | printk("\n"); |
5867 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5868 | break; |
5869 | } | |
5870 | ||
18a3885f | 5871 | if (!group->cpu_power) { |
3df0fc5b PZ |
5872 | printk(KERN_CONT "\n"); |
5873 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
5874 | "set\n"); | |
4dcf6aff IM |
5875 | break; |
5876 | } | |
1da177e4 | 5877 | |
758b2cdc | 5878 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5879 | printk(KERN_CONT "\n"); |
5880 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5881 | break; |
5882 | } | |
1da177e4 | 5883 | |
758b2cdc | 5884 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
5885 | printk(KERN_CONT "\n"); |
5886 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5887 | break; |
5888 | } | |
1da177e4 | 5889 | |
758b2cdc | 5890 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5891 | |
968ea6d8 | 5892 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5893 | |
3df0fc5b | 5894 | printk(KERN_CONT " %s", str); |
18a3885f | 5895 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
3df0fc5b PZ |
5896 | printk(KERN_CONT " (cpu_power = %d)", |
5897 | group->cpu_power); | |
381512cf | 5898 | } |
1da177e4 | 5899 | |
4dcf6aff IM |
5900 | group = group->next; |
5901 | } while (group != sd->groups); | |
3df0fc5b | 5902 | printk(KERN_CONT "\n"); |
1da177e4 | 5903 | |
758b2cdc | 5904 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 5905 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 5906 | |
758b2cdc RR |
5907 | if (sd->parent && |
5908 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
5909 | printk(KERN_ERR "ERROR: parent span is not a superset " |
5910 | "of domain->span\n"); | |
4dcf6aff IM |
5911 | return 0; |
5912 | } | |
1da177e4 | 5913 | |
4dcf6aff IM |
5914 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
5915 | { | |
d5dd3db1 | 5916 | cpumask_var_t groupmask; |
4dcf6aff | 5917 | int level = 0; |
1da177e4 | 5918 | |
f6630114 MT |
5919 | if (!sched_domain_debug_enabled) |
5920 | return; | |
5921 | ||
4dcf6aff IM |
5922 | if (!sd) { |
5923 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
5924 | return; | |
5925 | } | |
1da177e4 | 5926 | |
4dcf6aff IM |
5927 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
5928 | ||
d5dd3db1 | 5929 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
5930 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
5931 | return; | |
5932 | } | |
5933 | ||
4dcf6aff | 5934 | for (;;) { |
7c16ec58 | 5935 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 5936 | break; |
1da177e4 LT |
5937 | level++; |
5938 | sd = sd->parent; | |
33859f7f | 5939 | if (!sd) |
4dcf6aff IM |
5940 | break; |
5941 | } | |
d5dd3db1 | 5942 | free_cpumask_var(groupmask); |
1da177e4 | 5943 | } |
6d6bc0ad | 5944 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 5945 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 5946 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 5947 | |
1a20ff27 | 5948 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 5949 | { |
758b2cdc | 5950 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
5951 | return 1; |
5952 | ||
5953 | /* Following flags need at least 2 groups */ | |
5954 | if (sd->flags & (SD_LOAD_BALANCE | | |
5955 | SD_BALANCE_NEWIDLE | | |
5956 | SD_BALANCE_FORK | | |
89c4710e SS |
5957 | SD_BALANCE_EXEC | |
5958 | SD_SHARE_CPUPOWER | | |
5959 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
5960 | if (sd->groups != sd->groups->next) |
5961 | return 0; | |
5962 | } | |
5963 | ||
5964 | /* Following flags don't use groups */ | |
c88d5910 | 5965 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
5966 | return 0; |
5967 | ||
5968 | return 1; | |
5969 | } | |
5970 | ||
48f24c4d IM |
5971 | static int |
5972 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
5973 | { |
5974 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
5975 | ||
5976 | if (sd_degenerate(parent)) | |
5977 | return 1; | |
5978 | ||
758b2cdc | 5979 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
5980 | return 0; |
5981 | ||
245af2c7 SS |
5982 | /* Flags needing groups don't count if only 1 group in parent */ |
5983 | if (parent->groups == parent->groups->next) { | |
5984 | pflags &= ~(SD_LOAD_BALANCE | | |
5985 | SD_BALANCE_NEWIDLE | | |
5986 | SD_BALANCE_FORK | | |
89c4710e SS |
5987 | SD_BALANCE_EXEC | |
5988 | SD_SHARE_CPUPOWER | | |
5989 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
5990 | if (nr_node_ids == 1) |
5991 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
5992 | } |
5993 | if (~cflags & pflags) | |
5994 | return 0; | |
5995 | ||
5996 | return 1; | |
5997 | } | |
5998 | ||
c6c4927b RR |
5999 | static void free_rootdomain(struct root_domain *rd) |
6000 | { | |
047106ad PZ |
6001 | synchronize_sched(); |
6002 | ||
68e74568 RR |
6003 | cpupri_cleanup(&rd->cpupri); |
6004 | ||
c6c4927b RR |
6005 | free_cpumask_var(rd->rto_mask); |
6006 | free_cpumask_var(rd->online); | |
6007 | free_cpumask_var(rd->span); | |
6008 | kfree(rd); | |
6009 | } | |
6010 | ||
57d885fe GH |
6011 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6012 | { | |
a0490fa3 | 6013 | struct root_domain *old_rd = NULL; |
57d885fe | 6014 | unsigned long flags; |
57d885fe | 6015 | |
05fa785c | 6016 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6017 | |
6018 | if (rq->rd) { | |
a0490fa3 | 6019 | old_rd = rq->rd; |
57d885fe | 6020 | |
c6c4927b | 6021 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6022 | set_rq_offline(rq); |
57d885fe | 6023 | |
c6c4927b | 6024 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6025 | |
a0490fa3 IM |
6026 | /* |
6027 | * If we dont want to free the old_rt yet then | |
6028 | * set old_rd to NULL to skip the freeing later | |
6029 | * in this function: | |
6030 | */ | |
6031 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6032 | old_rd = NULL; | |
57d885fe GH |
6033 | } |
6034 | ||
6035 | atomic_inc(&rd->refcount); | |
6036 | rq->rd = rd; | |
6037 | ||
c6c4927b | 6038 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6039 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6040 | set_rq_online(rq); |
57d885fe | 6041 | |
05fa785c | 6042 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6043 | |
6044 | if (old_rd) | |
6045 | free_rootdomain(old_rd); | |
57d885fe GH |
6046 | } |
6047 | ||
fd5e1b5d | 6048 | static int init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe | 6049 | { |
36b7b6d4 PE |
6050 | gfp_t gfp = GFP_KERNEL; |
6051 | ||
57d885fe GH |
6052 | memset(rd, 0, sizeof(*rd)); |
6053 | ||
36b7b6d4 PE |
6054 | if (bootmem) |
6055 | gfp = GFP_NOWAIT; | |
c6c4927b | 6056 | |
36b7b6d4 | 6057 | if (!alloc_cpumask_var(&rd->span, gfp)) |
0c910d28 | 6058 | goto out; |
36b7b6d4 | 6059 | if (!alloc_cpumask_var(&rd->online, gfp)) |
c6c4927b | 6060 | goto free_span; |
36b7b6d4 | 6061 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) |
c6c4927b | 6062 | goto free_online; |
6e0534f2 | 6063 | |
0fb53029 | 6064 | if (cpupri_init(&rd->cpupri, bootmem) != 0) |
68e74568 | 6065 | goto free_rto_mask; |
c6c4927b | 6066 | return 0; |
6e0534f2 | 6067 | |
68e74568 RR |
6068 | free_rto_mask: |
6069 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6070 | free_online: |
6071 | free_cpumask_var(rd->online); | |
6072 | free_span: | |
6073 | free_cpumask_var(rd->span); | |
0c910d28 | 6074 | out: |
c6c4927b | 6075 | return -ENOMEM; |
57d885fe GH |
6076 | } |
6077 | ||
6078 | static void init_defrootdomain(void) | |
6079 | { | |
c6c4927b RR |
6080 | init_rootdomain(&def_root_domain, true); |
6081 | ||
57d885fe GH |
6082 | atomic_set(&def_root_domain.refcount, 1); |
6083 | } | |
6084 | ||
dc938520 | 6085 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6086 | { |
6087 | struct root_domain *rd; | |
6088 | ||
6089 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6090 | if (!rd) | |
6091 | return NULL; | |
6092 | ||
c6c4927b RR |
6093 | if (init_rootdomain(rd, false) != 0) { |
6094 | kfree(rd); | |
6095 | return NULL; | |
6096 | } | |
57d885fe GH |
6097 | |
6098 | return rd; | |
6099 | } | |
6100 | ||
1da177e4 | 6101 | /* |
0eab9146 | 6102 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
6103 | * hold the hotplug lock. |
6104 | */ | |
0eab9146 IM |
6105 | static void |
6106 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 6107 | { |
70b97a7f | 6108 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
6109 | struct sched_domain *tmp; |
6110 | ||
669c55e9 PZ |
6111 | for (tmp = sd; tmp; tmp = tmp->parent) |
6112 | tmp->span_weight = cpumask_weight(sched_domain_span(tmp)); | |
6113 | ||
245af2c7 | 6114 | /* Remove the sched domains which do not contribute to scheduling. */ |
f29c9b1c | 6115 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
6116 | struct sched_domain *parent = tmp->parent; |
6117 | if (!parent) | |
6118 | break; | |
f29c9b1c | 6119 | |
1a848870 | 6120 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 6121 | tmp->parent = parent->parent; |
1a848870 SS |
6122 | if (parent->parent) |
6123 | parent->parent->child = tmp; | |
f29c9b1c LZ |
6124 | } else |
6125 | tmp = tmp->parent; | |
245af2c7 SS |
6126 | } |
6127 | ||
1a848870 | 6128 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 6129 | sd = sd->parent; |
1a848870 SS |
6130 | if (sd) |
6131 | sd->child = NULL; | |
6132 | } | |
1da177e4 LT |
6133 | |
6134 | sched_domain_debug(sd, cpu); | |
6135 | ||
57d885fe | 6136 | rq_attach_root(rq, rd); |
674311d5 | 6137 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
6138 | } |
6139 | ||
6140 | /* cpus with isolated domains */ | |
dcc30a35 | 6141 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
6142 | |
6143 | /* Setup the mask of cpus configured for isolated domains */ | |
6144 | static int __init isolated_cpu_setup(char *str) | |
6145 | { | |
bdddd296 | 6146 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 6147 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
6148 | return 1; |
6149 | } | |
6150 | ||
8927f494 | 6151 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
6152 | |
6153 | /* | |
6711cab4 SS |
6154 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
6155 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
6156 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
6157 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
6158 | * |
6159 | * init_sched_build_groups will build a circular linked list of the groups | |
6160 | * covered by the given span, and will set each group's ->cpumask correctly, | |
6161 | * and ->cpu_power to 0. | |
6162 | */ | |
a616058b | 6163 | static void |
96f874e2 RR |
6164 | init_sched_build_groups(const struct cpumask *span, |
6165 | const struct cpumask *cpu_map, | |
6166 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 6167 | struct sched_group **sg, |
96f874e2 RR |
6168 | struct cpumask *tmpmask), |
6169 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
6170 | { |
6171 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
6172 | int i; |
6173 | ||
96f874e2 | 6174 | cpumask_clear(covered); |
7c16ec58 | 6175 | |
abcd083a | 6176 | for_each_cpu(i, span) { |
6711cab4 | 6177 | struct sched_group *sg; |
7c16ec58 | 6178 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
6179 | int j; |
6180 | ||
758b2cdc | 6181 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
6182 | continue; |
6183 | ||
758b2cdc | 6184 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 6185 | sg->cpu_power = 0; |
1da177e4 | 6186 | |
abcd083a | 6187 | for_each_cpu(j, span) { |
7c16ec58 | 6188 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
6189 | continue; |
6190 | ||
96f874e2 | 6191 | cpumask_set_cpu(j, covered); |
758b2cdc | 6192 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
6193 | } |
6194 | if (!first) | |
6195 | first = sg; | |
6196 | if (last) | |
6197 | last->next = sg; | |
6198 | last = sg; | |
6199 | } | |
6200 | last->next = first; | |
6201 | } | |
6202 | ||
9c1cfda2 | 6203 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 6204 | |
9c1cfda2 | 6205 | #ifdef CONFIG_NUMA |
198e2f18 | 6206 | |
9c1cfda2 JH |
6207 | /** |
6208 | * find_next_best_node - find the next node to include in a sched_domain | |
6209 | * @node: node whose sched_domain we're building | |
6210 | * @used_nodes: nodes already in the sched_domain | |
6211 | * | |
41a2d6cf | 6212 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
6213 | * finds the closest node not already in the @used_nodes map. |
6214 | * | |
6215 | * Should use nodemask_t. | |
6216 | */ | |
c5f59f08 | 6217 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
6218 | { |
6219 | int i, n, val, min_val, best_node = 0; | |
6220 | ||
6221 | min_val = INT_MAX; | |
6222 | ||
076ac2af | 6223 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 6224 | /* Start at @node */ |
076ac2af | 6225 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
6226 | |
6227 | if (!nr_cpus_node(n)) | |
6228 | continue; | |
6229 | ||
6230 | /* Skip already used nodes */ | |
c5f59f08 | 6231 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
6232 | continue; |
6233 | ||
6234 | /* Simple min distance search */ | |
6235 | val = node_distance(node, n); | |
6236 | ||
6237 | if (val < min_val) { | |
6238 | min_val = val; | |
6239 | best_node = n; | |
6240 | } | |
6241 | } | |
6242 | ||
c5f59f08 | 6243 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
6244 | return best_node; |
6245 | } | |
6246 | ||
6247 | /** | |
6248 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
6249 | * @node: node whose cpumask we're constructing | |
73486722 | 6250 | * @span: resulting cpumask |
9c1cfda2 | 6251 | * |
41a2d6cf | 6252 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
6253 | * should be one that prevents unnecessary balancing, but also spreads tasks |
6254 | * out optimally. | |
6255 | */ | |
96f874e2 | 6256 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 6257 | { |
c5f59f08 | 6258 | nodemask_t used_nodes; |
48f24c4d | 6259 | int i; |
9c1cfda2 | 6260 | |
6ca09dfc | 6261 | cpumask_clear(span); |
c5f59f08 | 6262 | nodes_clear(used_nodes); |
9c1cfda2 | 6263 | |
6ca09dfc | 6264 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 6265 | node_set(node, used_nodes); |
9c1cfda2 JH |
6266 | |
6267 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 6268 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 6269 | |
6ca09dfc | 6270 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 6271 | } |
9c1cfda2 | 6272 | } |
6d6bc0ad | 6273 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 6274 | |
5c45bf27 | 6275 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 6276 | |
6c99e9ad RR |
6277 | /* |
6278 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
6279 | * |
6280 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
6281 | * and struct sched_domain. ) | |
6c99e9ad RR |
6282 | */ |
6283 | struct static_sched_group { | |
6284 | struct sched_group sg; | |
6285 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
6286 | }; | |
6287 | ||
6288 | struct static_sched_domain { | |
6289 | struct sched_domain sd; | |
6290 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
6291 | }; | |
6292 | ||
49a02c51 AH |
6293 | struct s_data { |
6294 | #ifdef CONFIG_NUMA | |
6295 | int sd_allnodes; | |
6296 | cpumask_var_t domainspan; | |
6297 | cpumask_var_t covered; | |
6298 | cpumask_var_t notcovered; | |
6299 | #endif | |
6300 | cpumask_var_t nodemask; | |
6301 | cpumask_var_t this_sibling_map; | |
6302 | cpumask_var_t this_core_map; | |
6303 | cpumask_var_t send_covered; | |
6304 | cpumask_var_t tmpmask; | |
6305 | struct sched_group **sched_group_nodes; | |
6306 | struct root_domain *rd; | |
6307 | }; | |
6308 | ||
2109b99e AH |
6309 | enum s_alloc { |
6310 | sa_sched_groups = 0, | |
6311 | sa_rootdomain, | |
6312 | sa_tmpmask, | |
6313 | sa_send_covered, | |
6314 | sa_this_core_map, | |
6315 | sa_this_sibling_map, | |
6316 | sa_nodemask, | |
6317 | sa_sched_group_nodes, | |
6318 | #ifdef CONFIG_NUMA | |
6319 | sa_notcovered, | |
6320 | sa_covered, | |
6321 | sa_domainspan, | |
6322 | #endif | |
6323 | sa_none, | |
6324 | }; | |
6325 | ||
9c1cfda2 | 6326 | /* |
48f24c4d | 6327 | * SMT sched-domains: |
9c1cfda2 | 6328 | */ |
1da177e4 | 6329 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 6330 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
1871e52c | 6331 | static DEFINE_PER_CPU(struct static_sched_group, sched_groups); |
48f24c4d | 6332 | |
41a2d6cf | 6333 | static int |
96f874e2 RR |
6334 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
6335 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 6336 | { |
6711cab4 | 6337 | if (sg) |
1871e52c | 6338 | *sg = &per_cpu(sched_groups, cpu).sg; |
1da177e4 LT |
6339 | return cpu; |
6340 | } | |
6d6bc0ad | 6341 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 6342 | |
48f24c4d IM |
6343 | /* |
6344 | * multi-core sched-domains: | |
6345 | */ | |
1e9f28fa | 6346 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
6347 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
6348 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 6349 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
6350 | |
6351 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 6352 | static int |
96f874e2 RR |
6353 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6354 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 6355 | { |
6711cab4 | 6356 | int group; |
7c16ec58 | 6357 | |
c69fc56d | 6358 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6359 | group = cpumask_first(mask); |
6711cab4 | 6360 | if (sg) |
6c99e9ad | 6361 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 6362 | return group; |
1e9f28fa SS |
6363 | } |
6364 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 6365 | static int |
96f874e2 RR |
6366 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6367 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 6368 | { |
6711cab4 | 6369 | if (sg) |
6c99e9ad | 6370 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
6371 | return cpu; |
6372 | } | |
6373 | #endif | |
6374 | ||
6c99e9ad RR |
6375 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
6376 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 6377 | |
41a2d6cf | 6378 | static int |
96f874e2 RR |
6379 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
6380 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 6381 | { |
6711cab4 | 6382 | int group; |
48f24c4d | 6383 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 6384 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 6385 | group = cpumask_first(mask); |
1e9f28fa | 6386 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 6387 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6388 | group = cpumask_first(mask); |
1da177e4 | 6389 | #else |
6711cab4 | 6390 | group = cpu; |
1da177e4 | 6391 | #endif |
6711cab4 | 6392 | if (sg) |
6c99e9ad | 6393 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 6394 | return group; |
1da177e4 LT |
6395 | } |
6396 | ||
6397 | #ifdef CONFIG_NUMA | |
1da177e4 | 6398 | /* |
9c1cfda2 JH |
6399 | * The init_sched_build_groups can't handle what we want to do with node |
6400 | * groups, so roll our own. Now each node has its own list of groups which | |
6401 | * gets dynamically allocated. | |
1da177e4 | 6402 | */ |
62ea9ceb | 6403 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 6404 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 6405 | |
62ea9ceb | 6406 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 6407 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 6408 | |
96f874e2 RR |
6409 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
6410 | struct sched_group **sg, | |
6411 | struct cpumask *nodemask) | |
9c1cfda2 | 6412 | { |
6711cab4 SS |
6413 | int group; |
6414 | ||
6ca09dfc | 6415 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 6416 | group = cpumask_first(nodemask); |
6711cab4 SS |
6417 | |
6418 | if (sg) | |
6c99e9ad | 6419 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 6420 | return group; |
1da177e4 | 6421 | } |
6711cab4 | 6422 | |
08069033 SS |
6423 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
6424 | { | |
6425 | struct sched_group *sg = group_head; | |
6426 | int j; | |
6427 | ||
6428 | if (!sg) | |
6429 | return; | |
3a5c359a | 6430 | do { |
758b2cdc | 6431 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 6432 | struct sched_domain *sd; |
08069033 | 6433 | |
6c99e9ad | 6434 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 6435 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
6436 | /* |
6437 | * Only add "power" once for each | |
6438 | * physical package. | |
6439 | */ | |
6440 | continue; | |
6441 | } | |
08069033 | 6442 | |
18a3885f | 6443 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
6444 | } |
6445 | sg = sg->next; | |
6446 | } while (sg != group_head); | |
08069033 | 6447 | } |
0601a88d AH |
6448 | |
6449 | static int build_numa_sched_groups(struct s_data *d, | |
6450 | const struct cpumask *cpu_map, int num) | |
6451 | { | |
6452 | struct sched_domain *sd; | |
6453 | struct sched_group *sg, *prev; | |
6454 | int n, j; | |
6455 | ||
6456 | cpumask_clear(d->covered); | |
6457 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
6458 | if (cpumask_empty(d->nodemask)) { | |
6459 | d->sched_group_nodes[num] = NULL; | |
6460 | goto out; | |
6461 | } | |
6462 | ||
6463 | sched_domain_node_span(num, d->domainspan); | |
6464 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
6465 | ||
6466 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6467 | GFP_KERNEL, num); | |
6468 | if (!sg) { | |
3df0fc5b PZ |
6469 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", |
6470 | num); | |
0601a88d AH |
6471 | return -ENOMEM; |
6472 | } | |
6473 | d->sched_group_nodes[num] = sg; | |
6474 | ||
6475 | for_each_cpu(j, d->nodemask) { | |
6476 | sd = &per_cpu(node_domains, j).sd; | |
6477 | sd->groups = sg; | |
6478 | } | |
6479 | ||
18a3885f | 6480 | sg->cpu_power = 0; |
0601a88d AH |
6481 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
6482 | sg->next = sg; | |
6483 | cpumask_or(d->covered, d->covered, d->nodemask); | |
6484 | ||
6485 | prev = sg; | |
6486 | for (j = 0; j < nr_node_ids; j++) { | |
6487 | n = (num + j) % nr_node_ids; | |
6488 | cpumask_complement(d->notcovered, d->covered); | |
6489 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
6490 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
6491 | if (cpumask_empty(d->tmpmask)) | |
6492 | break; | |
6493 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
6494 | if (cpumask_empty(d->tmpmask)) | |
6495 | continue; | |
6496 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6497 | GFP_KERNEL, num); | |
6498 | if (!sg) { | |
3df0fc5b PZ |
6499 | printk(KERN_WARNING |
6500 | "Can not alloc domain group for node %d\n", j); | |
0601a88d AH |
6501 | return -ENOMEM; |
6502 | } | |
18a3885f | 6503 | sg->cpu_power = 0; |
0601a88d AH |
6504 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
6505 | sg->next = prev->next; | |
6506 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
6507 | prev->next = sg; | |
6508 | prev = sg; | |
6509 | } | |
6510 | out: | |
6511 | return 0; | |
6512 | } | |
6d6bc0ad | 6513 | #endif /* CONFIG_NUMA */ |
1da177e4 | 6514 | |
a616058b | 6515 | #ifdef CONFIG_NUMA |
51888ca2 | 6516 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
6517 | static void free_sched_groups(const struct cpumask *cpu_map, |
6518 | struct cpumask *nodemask) | |
51888ca2 | 6519 | { |
a616058b | 6520 | int cpu, i; |
51888ca2 | 6521 | |
abcd083a | 6522 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
6523 | struct sched_group **sched_group_nodes |
6524 | = sched_group_nodes_bycpu[cpu]; | |
6525 | ||
51888ca2 SV |
6526 | if (!sched_group_nodes) |
6527 | continue; | |
6528 | ||
076ac2af | 6529 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
6530 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
6531 | ||
6ca09dfc | 6532 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 6533 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
6534 | continue; |
6535 | ||
6536 | if (sg == NULL) | |
6537 | continue; | |
6538 | sg = sg->next; | |
6539 | next_sg: | |
6540 | oldsg = sg; | |
6541 | sg = sg->next; | |
6542 | kfree(oldsg); | |
6543 | if (oldsg != sched_group_nodes[i]) | |
6544 | goto next_sg; | |
6545 | } | |
6546 | kfree(sched_group_nodes); | |
6547 | sched_group_nodes_bycpu[cpu] = NULL; | |
6548 | } | |
51888ca2 | 6549 | } |
6d6bc0ad | 6550 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
6551 | static void free_sched_groups(const struct cpumask *cpu_map, |
6552 | struct cpumask *nodemask) | |
a616058b SS |
6553 | { |
6554 | } | |
6d6bc0ad | 6555 | #endif /* CONFIG_NUMA */ |
51888ca2 | 6556 | |
89c4710e SS |
6557 | /* |
6558 | * Initialize sched groups cpu_power. | |
6559 | * | |
6560 | * cpu_power indicates the capacity of sched group, which is used while | |
6561 | * distributing the load between different sched groups in a sched domain. | |
6562 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
6563 | * there are asymmetries in the topology. If there are asymmetries, group | |
6564 | * having more cpu_power will pickup more load compared to the group having | |
6565 | * less cpu_power. | |
89c4710e SS |
6566 | */ |
6567 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
6568 | { | |
6569 | struct sched_domain *child; | |
6570 | struct sched_group *group; | |
f93e65c1 PZ |
6571 | long power; |
6572 | int weight; | |
89c4710e SS |
6573 | |
6574 | WARN_ON(!sd || !sd->groups); | |
6575 | ||
13318a71 | 6576 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
6577 | return; |
6578 | ||
6579 | child = sd->child; | |
6580 | ||
18a3885f | 6581 | sd->groups->cpu_power = 0; |
5517d86b | 6582 | |
f93e65c1 PZ |
6583 | if (!child) { |
6584 | power = SCHED_LOAD_SCALE; | |
6585 | weight = cpumask_weight(sched_domain_span(sd)); | |
6586 | /* | |
6587 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
6588 | * Usually multiple threads get a better yield out of |
6589 | * that one core than a single thread would have, | |
6590 | * reflect that in sd->smt_gain. | |
f93e65c1 | 6591 | */ |
a52bfd73 PZ |
6592 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
6593 | power *= sd->smt_gain; | |
f93e65c1 | 6594 | power /= weight; |
a52bfd73 PZ |
6595 | power >>= SCHED_LOAD_SHIFT; |
6596 | } | |
18a3885f | 6597 | sd->groups->cpu_power += power; |
89c4710e SS |
6598 | return; |
6599 | } | |
6600 | ||
89c4710e | 6601 | /* |
f93e65c1 | 6602 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
6603 | */ |
6604 | group = child->groups; | |
6605 | do { | |
18a3885f | 6606 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
6607 | group = group->next; |
6608 | } while (group != child->groups); | |
6609 | } | |
6610 | ||
7c16ec58 MT |
6611 | /* |
6612 | * Initializers for schedule domains | |
6613 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
6614 | */ | |
6615 | ||
a5d8c348 IM |
6616 | #ifdef CONFIG_SCHED_DEBUG |
6617 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
6618 | #else | |
6619 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
6620 | #endif | |
6621 | ||
7c16ec58 | 6622 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 6623 | |
7c16ec58 MT |
6624 | #define SD_INIT_FUNC(type) \ |
6625 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
6626 | { \ | |
6627 | memset(sd, 0, sizeof(*sd)); \ | |
6628 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 6629 | sd->level = SD_LV_##type; \ |
a5d8c348 | 6630 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
6631 | } |
6632 | ||
6633 | SD_INIT_FUNC(CPU) | |
6634 | #ifdef CONFIG_NUMA | |
6635 | SD_INIT_FUNC(ALLNODES) | |
6636 | SD_INIT_FUNC(NODE) | |
6637 | #endif | |
6638 | #ifdef CONFIG_SCHED_SMT | |
6639 | SD_INIT_FUNC(SIBLING) | |
6640 | #endif | |
6641 | #ifdef CONFIG_SCHED_MC | |
6642 | SD_INIT_FUNC(MC) | |
6643 | #endif | |
6644 | ||
1d3504fc HS |
6645 | static int default_relax_domain_level = -1; |
6646 | ||
6647 | static int __init setup_relax_domain_level(char *str) | |
6648 | { | |
30e0e178 LZ |
6649 | unsigned long val; |
6650 | ||
6651 | val = simple_strtoul(str, NULL, 0); | |
6652 | if (val < SD_LV_MAX) | |
6653 | default_relax_domain_level = val; | |
6654 | ||
1d3504fc HS |
6655 | return 1; |
6656 | } | |
6657 | __setup("relax_domain_level=", setup_relax_domain_level); | |
6658 | ||
6659 | static void set_domain_attribute(struct sched_domain *sd, | |
6660 | struct sched_domain_attr *attr) | |
6661 | { | |
6662 | int request; | |
6663 | ||
6664 | if (!attr || attr->relax_domain_level < 0) { | |
6665 | if (default_relax_domain_level < 0) | |
6666 | return; | |
6667 | else | |
6668 | request = default_relax_domain_level; | |
6669 | } else | |
6670 | request = attr->relax_domain_level; | |
6671 | if (request < sd->level) { | |
6672 | /* turn off idle balance on this domain */ | |
c88d5910 | 6673 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6674 | } else { |
6675 | /* turn on idle balance on this domain */ | |
c88d5910 | 6676 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6677 | } |
6678 | } | |
6679 | ||
2109b99e AH |
6680 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
6681 | const struct cpumask *cpu_map) | |
6682 | { | |
6683 | switch (what) { | |
6684 | case sa_sched_groups: | |
6685 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
6686 | d->sched_group_nodes = NULL; | |
6687 | case sa_rootdomain: | |
6688 | free_rootdomain(d->rd); /* fall through */ | |
6689 | case sa_tmpmask: | |
6690 | free_cpumask_var(d->tmpmask); /* fall through */ | |
6691 | case sa_send_covered: | |
6692 | free_cpumask_var(d->send_covered); /* fall through */ | |
6693 | case sa_this_core_map: | |
6694 | free_cpumask_var(d->this_core_map); /* fall through */ | |
6695 | case sa_this_sibling_map: | |
6696 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
6697 | case sa_nodemask: | |
6698 | free_cpumask_var(d->nodemask); /* fall through */ | |
6699 | case sa_sched_group_nodes: | |
d1b55138 | 6700 | #ifdef CONFIG_NUMA |
2109b99e AH |
6701 | kfree(d->sched_group_nodes); /* fall through */ |
6702 | case sa_notcovered: | |
6703 | free_cpumask_var(d->notcovered); /* fall through */ | |
6704 | case sa_covered: | |
6705 | free_cpumask_var(d->covered); /* fall through */ | |
6706 | case sa_domainspan: | |
6707 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 6708 | #endif |
2109b99e AH |
6709 | case sa_none: |
6710 | break; | |
6711 | } | |
6712 | } | |
3404c8d9 | 6713 | |
2109b99e AH |
6714 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
6715 | const struct cpumask *cpu_map) | |
6716 | { | |
3404c8d9 | 6717 | #ifdef CONFIG_NUMA |
2109b99e AH |
6718 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
6719 | return sa_none; | |
6720 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
6721 | return sa_domainspan; | |
6722 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
6723 | return sa_covered; | |
6724 | /* Allocate the per-node list of sched groups */ | |
6725 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
6726 | sizeof(struct sched_group *), GFP_KERNEL); | |
6727 | if (!d->sched_group_nodes) { | |
3df0fc5b | 6728 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 6729 | return sa_notcovered; |
d1b55138 | 6730 | } |
2109b99e | 6731 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 6732 | #endif |
2109b99e AH |
6733 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
6734 | return sa_sched_group_nodes; | |
6735 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
6736 | return sa_nodemask; | |
6737 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
6738 | return sa_this_sibling_map; | |
6739 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
6740 | return sa_this_core_map; | |
6741 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
6742 | return sa_send_covered; | |
6743 | d->rd = alloc_rootdomain(); | |
6744 | if (!d->rd) { | |
3df0fc5b | 6745 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 6746 | return sa_tmpmask; |
57d885fe | 6747 | } |
2109b99e AH |
6748 | return sa_rootdomain; |
6749 | } | |
57d885fe | 6750 | |
7f4588f3 AH |
6751 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
6752 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
6753 | { | |
6754 | struct sched_domain *sd = NULL; | |
7c16ec58 | 6755 | #ifdef CONFIG_NUMA |
7f4588f3 | 6756 | struct sched_domain *parent; |
1da177e4 | 6757 | |
7f4588f3 AH |
6758 | d->sd_allnodes = 0; |
6759 | if (cpumask_weight(cpu_map) > | |
6760 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
6761 | sd = &per_cpu(allnodes_domains, i).sd; | |
6762 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 6763 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
6764 | cpumask_copy(sched_domain_span(sd), cpu_map); |
6765 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6766 | d->sd_allnodes = 1; | |
6767 | } | |
6768 | parent = sd; | |
6769 | ||
6770 | sd = &per_cpu(node_domains, i).sd; | |
6771 | SD_INIT(sd, NODE); | |
6772 | set_domain_attribute(sd, attr); | |
6773 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
6774 | sd->parent = parent; | |
6775 | if (parent) | |
6776 | parent->child = sd; | |
6777 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 6778 | #endif |
7f4588f3 AH |
6779 | return sd; |
6780 | } | |
1da177e4 | 6781 | |
87cce662 AH |
6782 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
6783 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6784 | struct sched_domain *parent, int i) | |
6785 | { | |
6786 | struct sched_domain *sd; | |
6787 | sd = &per_cpu(phys_domains, i).sd; | |
6788 | SD_INIT(sd, CPU); | |
6789 | set_domain_attribute(sd, attr); | |
6790 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
6791 | sd->parent = parent; | |
6792 | if (parent) | |
6793 | parent->child = sd; | |
6794 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6795 | return sd; | |
6796 | } | |
1da177e4 | 6797 | |
410c4081 AH |
6798 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
6799 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6800 | struct sched_domain *parent, int i) | |
6801 | { | |
6802 | struct sched_domain *sd = parent; | |
1e9f28fa | 6803 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
6804 | sd = &per_cpu(core_domains, i).sd; |
6805 | SD_INIT(sd, MC); | |
6806 | set_domain_attribute(sd, attr); | |
6807 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
6808 | sd->parent = parent; | |
6809 | parent->child = sd; | |
6810 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 6811 | #endif |
410c4081 AH |
6812 | return sd; |
6813 | } | |
1e9f28fa | 6814 | |
d8173535 AH |
6815 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
6816 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6817 | struct sched_domain *parent, int i) | |
6818 | { | |
6819 | struct sched_domain *sd = parent; | |
1da177e4 | 6820 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
6821 | sd = &per_cpu(cpu_domains, i).sd; |
6822 | SD_INIT(sd, SIBLING); | |
6823 | set_domain_attribute(sd, attr); | |
6824 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
6825 | sd->parent = parent; | |
6826 | parent->child = sd; | |
6827 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 6828 | #endif |
d8173535 AH |
6829 | return sd; |
6830 | } | |
1da177e4 | 6831 | |
0e8e85c9 AH |
6832 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
6833 | const struct cpumask *cpu_map, int cpu) | |
6834 | { | |
6835 | switch (l) { | |
1da177e4 | 6836 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
6837 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
6838 | cpumask_and(d->this_sibling_map, cpu_map, | |
6839 | topology_thread_cpumask(cpu)); | |
6840 | if (cpu == cpumask_first(d->this_sibling_map)) | |
6841 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
6842 | &cpu_to_cpu_group, | |
6843 | d->send_covered, d->tmpmask); | |
6844 | break; | |
1da177e4 | 6845 | #endif |
1e9f28fa | 6846 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
6847 | case SD_LV_MC: /* set up multi-core groups */ |
6848 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
6849 | if (cpu == cpumask_first(d->this_core_map)) | |
6850 | init_sched_build_groups(d->this_core_map, cpu_map, | |
6851 | &cpu_to_core_group, | |
6852 | d->send_covered, d->tmpmask); | |
6853 | break; | |
1e9f28fa | 6854 | #endif |
86548096 AH |
6855 | case SD_LV_CPU: /* set up physical groups */ |
6856 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
6857 | if (!cpumask_empty(d->nodemask)) | |
6858 | init_sched_build_groups(d->nodemask, cpu_map, | |
6859 | &cpu_to_phys_group, | |
6860 | d->send_covered, d->tmpmask); | |
6861 | break; | |
1da177e4 | 6862 | #ifdef CONFIG_NUMA |
de616e36 AH |
6863 | case SD_LV_ALLNODES: |
6864 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
6865 | d->send_covered, d->tmpmask); | |
6866 | break; | |
6867 | #endif | |
0e8e85c9 AH |
6868 | default: |
6869 | break; | |
7c16ec58 | 6870 | } |
0e8e85c9 | 6871 | } |
9c1cfda2 | 6872 | |
2109b99e AH |
6873 | /* |
6874 | * Build sched domains for a given set of cpus and attach the sched domains | |
6875 | * to the individual cpus | |
6876 | */ | |
6877 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
6878 | struct sched_domain_attr *attr) | |
6879 | { | |
6880 | enum s_alloc alloc_state = sa_none; | |
6881 | struct s_data d; | |
294b0c96 | 6882 | struct sched_domain *sd; |
2109b99e | 6883 | int i; |
7c16ec58 | 6884 | #ifdef CONFIG_NUMA |
2109b99e | 6885 | d.sd_allnodes = 0; |
7c16ec58 | 6886 | #endif |
9c1cfda2 | 6887 | |
2109b99e AH |
6888 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6889 | if (alloc_state != sa_rootdomain) | |
6890 | goto error; | |
6891 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 6892 | |
1da177e4 | 6893 | /* |
1a20ff27 | 6894 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 6895 | */ |
abcd083a | 6896 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
6897 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
6898 | cpu_map); | |
9761eea8 | 6899 | |
7f4588f3 | 6900 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 6901 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 6902 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 6903 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 6904 | } |
9c1cfda2 | 6905 | |
abcd083a | 6906 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 6907 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 6908 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 6909 | } |
9c1cfda2 | 6910 | |
1da177e4 | 6911 | /* Set up physical groups */ |
86548096 AH |
6912 | for (i = 0; i < nr_node_ids; i++) |
6913 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 6914 | |
1da177e4 LT |
6915 | #ifdef CONFIG_NUMA |
6916 | /* Set up node groups */ | |
de616e36 AH |
6917 | if (d.sd_allnodes) |
6918 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 6919 | |
0601a88d AH |
6920 | for (i = 0; i < nr_node_ids; i++) |
6921 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 6922 | goto error; |
1da177e4 LT |
6923 | #endif |
6924 | ||
6925 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 6926 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 6927 | for_each_cpu(i, cpu_map) { |
294b0c96 | 6928 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 6929 | init_sched_groups_power(i, sd); |
5c45bf27 | 6930 | } |
1da177e4 | 6931 | #endif |
1e9f28fa | 6932 | #ifdef CONFIG_SCHED_MC |
abcd083a | 6933 | for_each_cpu(i, cpu_map) { |
294b0c96 | 6934 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 6935 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
6936 | } |
6937 | #endif | |
1e9f28fa | 6938 | |
abcd083a | 6939 | for_each_cpu(i, cpu_map) { |
294b0c96 | 6940 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 6941 | init_sched_groups_power(i, sd); |
1da177e4 LT |
6942 | } |
6943 | ||
9c1cfda2 | 6944 | #ifdef CONFIG_NUMA |
076ac2af | 6945 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 6946 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 6947 | |
49a02c51 | 6948 | if (d.sd_allnodes) { |
6711cab4 | 6949 | struct sched_group *sg; |
f712c0c7 | 6950 | |
96f874e2 | 6951 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 6952 | d.tmpmask); |
f712c0c7 SS |
6953 | init_numa_sched_groups_power(sg); |
6954 | } | |
9c1cfda2 JH |
6955 | #endif |
6956 | ||
1da177e4 | 6957 | /* Attach the domains */ |
abcd083a | 6958 | for_each_cpu(i, cpu_map) { |
1da177e4 | 6959 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 6960 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 6961 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 6962 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 6963 | #else |
6c99e9ad | 6964 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 6965 | #endif |
49a02c51 | 6966 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 6967 | } |
51888ca2 | 6968 | |
2109b99e AH |
6969 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
6970 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
6971 | return 0; | |
51888ca2 | 6972 | |
51888ca2 | 6973 | error: |
2109b99e AH |
6974 | __free_domain_allocs(&d, alloc_state, cpu_map); |
6975 | return -ENOMEM; | |
1da177e4 | 6976 | } |
029190c5 | 6977 | |
96f874e2 | 6978 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
6979 | { |
6980 | return __build_sched_domains(cpu_map, NULL); | |
6981 | } | |
6982 | ||
acc3f5d7 | 6983 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 6984 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
6985 | static struct sched_domain_attr *dattr_cur; |
6986 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
6987 | |
6988 | /* | |
6989 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
6990 | * cpumask) fails, then fallback to a single sched domain, |
6991 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 6992 | */ |
4212823f | 6993 | static cpumask_var_t fallback_doms; |
029190c5 | 6994 | |
ee79d1bd HC |
6995 | /* |
6996 | * arch_update_cpu_topology lets virtualized architectures update the | |
6997 | * cpu core maps. It is supposed to return 1 if the topology changed | |
6998 | * or 0 if it stayed the same. | |
6999 | */ | |
7000 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7001 | { |
ee79d1bd | 7002 | return 0; |
22e52b07 HC |
7003 | } |
7004 | ||
acc3f5d7 RR |
7005 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7006 | { | |
7007 | int i; | |
7008 | cpumask_var_t *doms; | |
7009 | ||
7010 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7011 | if (!doms) | |
7012 | return NULL; | |
7013 | for (i = 0; i < ndoms; i++) { | |
7014 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7015 | free_sched_domains(doms, i); | |
7016 | return NULL; | |
7017 | } | |
7018 | } | |
7019 | return doms; | |
7020 | } | |
7021 | ||
7022 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7023 | { | |
7024 | unsigned int i; | |
7025 | for (i = 0; i < ndoms; i++) | |
7026 | free_cpumask_var(doms[i]); | |
7027 | kfree(doms); | |
7028 | } | |
7029 | ||
1a20ff27 | 7030 | /* |
41a2d6cf | 7031 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7032 | * For now this just excludes isolated cpus, but could be used to |
7033 | * exclude other special cases in the future. | |
1a20ff27 | 7034 | */ |
96f874e2 | 7035 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7036 | { |
7378547f MM |
7037 | int err; |
7038 | ||
22e52b07 | 7039 | arch_update_cpu_topology(); |
029190c5 | 7040 | ndoms_cur = 1; |
acc3f5d7 | 7041 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7042 | if (!doms_cur) |
acc3f5d7 RR |
7043 | doms_cur = &fallback_doms; |
7044 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7045 | dattr_cur = NULL; |
acc3f5d7 | 7046 | err = build_sched_domains(doms_cur[0]); |
6382bc90 | 7047 | register_sched_domain_sysctl(); |
7378547f MM |
7048 | |
7049 | return err; | |
1a20ff27 DG |
7050 | } |
7051 | ||
96f874e2 RR |
7052 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
7053 | struct cpumask *tmpmask) | |
1da177e4 | 7054 | { |
7c16ec58 | 7055 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7056 | } |
1da177e4 | 7057 | |
1a20ff27 DG |
7058 | /* |
7059 | * Detach sched domains from a group of cpus specified in cpu_map | |
7060 | * These cpus will now be attached to the NULL domain | |
7061 | */ | |
96f874e2 | 7062 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7063 | { |
96f874e2 RR |
7064 | /* Save because hotplug lock held. */ |
7065 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
7066 | int i; |
7067 | ||
abcd083a | 7068 | for_each_cpu(i, cpu_map) |
57d885fe | 7069 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 7070 | synchronize_sched(); |
96f874e2 | 7071 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
7072 | } |
7073 | ||
1d3504fc HS |
7074 | /* handle null as "default" */ |
7075 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7076 | struct sched_domain_attr *new, int idx_new) | |
7077 | { | |
7078 | struct sched_domain_attr tmp; | |
7079 | ||
7080 | /* fast path */ | |
7081 | if (!new && !cur) | |
7082 | return 1; | |
7083 | ||
7084 | tmp = SD_ATTR_INIT; | |
7085 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7086 | new ? (new + idx_new) : &tmp, | |
7087 | sizeof(struct sched_domain_attr)); | |
7088 | } | |
7089 | ||
029190c5 PJ |
7090 | /* |
7091 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7092 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7093 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7094 | * It destroys each deleted domain and builds each new domain. | |
7095 | * | |
acc3f5d7 | 7096 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7097 | * The masks don't intersect (don't overlap.) We should setup one |
7098 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7099 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7100 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7101 | * it as it is. | |
7102 | * | |
acc3f5d7 RR |
7103 | * The passed in 'doms_new' should be allocated using |
7104 | * alloc_sched_domains. This routine takes ownership of it and will | |
7105 | * free_sched_domains it when done with it. If the caller failed the | |
7106 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7107 | * and partition_sched_domains() will fallback to the single partition | |
7108 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7109 | * |
96f874e2 | 7110 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7111 | * ndoms_new == 0 is a special case for destroying existing domains, |
7112 | * and it will not create the default domain. | |
dfb512ec | 7113 | * |
029190c5 PJ |
7114 | * Call with hotplug lock held |
7115 | */ | |
acc3f5d7 | 7116 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7117 | struct sched_domain_attr *dattr_new) |
029190c5 | 7118 | { |
dfb512ec | 7119 | int i, j, n; |
d65bd5ec | 7120 | int new_topology; |
029190c5 | 7121 | |
712555ee | 7122 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7123 | |
7378547f MM |
7124 | /* always unregister in case we don't destroy any domains */ |
7125 | unregister_sched_domain_sysctl(); | |
7126 | ||
d65bd5ec HC |
7127 | /* Let architecture update cpu core mappings. */ |
7128 | new_topology = arch_update_cpu_topology(); | |
7129 | ||
dfb512ec | 7130 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7131 | |
7132 | /* Destroy deleted domains */ | |
7133 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7134 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7135 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7136 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7137 | goto match1; |
7138 | } | |
7139 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7140 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7141 | match1: |
7142 | ; | |
7143 | } | |
7144 | ||
e761b772 MK |
7145 | if (doms_new == NULL) { |
7146 | ndoms_cur = 0; | |
acc3f5d7 | 7147 | doms_new = &fallback_doms; |
6ad4c188 | 7148 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7149 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7150 | } |
7151 | ||
029190c5 PJ |
7152 | /* Build new domains */ |
7153 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7154 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7155 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7156 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7157 | goto match2; |
7158 | } | |
7159 | /* no match - add a new doms_new */ | |
acc3f5d7 | 7160 | __build_sched_domains(doms_new[i], |
1d3504fc | 7161 | dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7162 | match2: |
7163 | ; | |
7164 | } | |
7165 | ||
7166 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7167 | if (doms_cur != &fallback_doms) |
7168 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7169 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7170 | doms_cur = doms_new; |
1d3504fc | 7171 | dattr_cur = dattr_new; |
029190c5 | 7172 | ndoms_cur = ndoms_new; |
7378547f MM |
7173 | |
7174 | register_sched_domain_sysctl(); | |
a1835615 | 7175 | |
712555ee | 7176 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7177 | } |
7178 | ||
5c45bf27 | 7179 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 7180 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 7181 | { |
95402b38 | 7182 | get_online_cpus(); |
dfb512ec MK |
7183 | |
7184 | /* Destroy domains first to force the rebuild */ | |
7185 | partition_sched_domains(0, NULL, NULL); | |
7186 | ||
e761b772 | 7187 | rebuild_sched_domains(); |
95402b38 | 7188 | put_online_cpus(); |
5c45bf27 SS |
7189 | } |
7190 | ||
7191 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7192 | { | |
afb8a9b7 | 7193 | unsigned int level = 0; |
5c45bf27 | 7194 | |
afb8a9b7 GS |
7195 | if (sscanf(buf, "%u", &level) != 1) |
7196 | return -EINVAL; | |
7197 | ||
7198 | /* | |
7199 | * level is always be positive so don't check for | |
7200 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7201 | * What happens on 0 or 1 byte write, | |
7202 | * need to check for count as well? | |
7203 | */ | |
7204 | ||
7205 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7206 | return -EINVAL; |
7207 | ||
7208 | if (smt) | |
afb8a9b7 | 7209 | sched_smt_power_savings = level; |
5c45bf27 | 7210 | else |
afb8a9b7 | 7211 | sched_mc_power_savings = level; |
5c45bf27 | 7212 | |
c70f22d2 | 7213 | arch_reinit_sched_domains(); |
5c45bf27 | 7214 | |
c70f22d2 | 7215 | return count; |
5c45bf27 SS |
7216 | } |
7217 | ||
5c45bf27 | 7218 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7219 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7220 | struct sysdev_class_attribute *attr, |
f718cd4a | 7221 | char *page) |
5c45bf27 SS |
7222 | { |
7223 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7224 | } | |
f718cd4a | 7225 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7226 | struct sysdev_class_attribute *attr, |
48f24c4d | 7227 | const char *buf, size_t count) |
5c45bf27 SS |
7228 | { |
7229 | return sched_power_savings_store(buf, count, 0); | |
7230 | } | |
f718cd4a AK |
7231 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7232 | sched_mc_power_savings_show, | |
7233 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7234 | #endif |
7235 | ||
7236 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7237 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7238 | struct sysdev_class_attribute *attr, |
f718cd4a | 7239 | char *page) |
5c45bf27 SS |
7240 | { |
7241 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7242 | } | |
f718cd4a | 7243 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7244 | struct sysdev_class_attribute *attr, |
48f24c4d | 7245 | const char *buf, size_t count) |
5c45bf27 SS |
7246 | { |
7247 | return sched_power_savings_store(buf, count, 1); | |
7248 | } | |
f718cd4a AK |
7249 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7250 | sched_smt_power_savings_show, | |
6707de00 AB |
7251 | sched_smt_power_savings_store); |
7252 | #endif | |
7253 | ||
39aac648 | 7254 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7255 | { |
7256 | int err = 0; | |
7257 | ||
7258 | #ifdef CONFIG_SCHED_SMT | |
7259 | if (smt_capable()) | |
7260 | err = sysfs_create_file(&cls->kset.kobj, | |
7261 | &attr_sched_smt_power_savings.attr); | |
7262 | #endif | |
7263 | #ifdef CONFIG_SCHED_MC | |
7264 | if (!err && mc_capable()) | |
7265 | err = sysfs_create_file(&cls->kset.kobj, | |
7266 | &attr_sched_mc_power_savings.attr); | |
7267 | #endif | |
7268 | return err; | |
7269 | } | |
6d6bc0ad | 7270 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7271 | |
e761b772 | 7272 | #ifndef CONFIG_CPUSETS |
1da177e4 | 7273 | /* |
e761b772 MK |
7274 | * Add online and remove offline CPUs from the scheduler domains. |
7275 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
7276 | */ |
7277 | static int update_sched_domains(struct notifier_block *nfb, | |
7278 | unsigned long action, void *hcpu) | |
e761b772 MK |
7279 | { |
7280 | switch (action) { | |
7281 | case CPU_ONLINE: | |
7282 | case CPU_ONLINE_FROZEN: | |
6ad4c188 PZ |
7283 | case CPU_DOWN_PREPARE: |
7284 | case CPU_DOWN_PREPARE_FROZEN: | |
7285 | case CPU_DOWN_FAILED: | |
7286 | case CPU_DOWN_FAILED_FROZEN: | |
dfb512ec | 7287 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
7288 | return NOTIFY_OK; |
7289 | ||
7290 | default: | |
7291 | return NOTIFY_DONE; | |
7292 | } | |
7293 | } | |
7294 | #endif | |
7295 | ||
7296 | static int update_runtime(struct notifier_block *nfb, | |
7297 | unsigned long action, void *hcpu) | |
1da177e4 | 7298 | { |
7def2be1 PZ |
7299 | int cpu = (int)(long)hcpu; |
7300 | ||
1da177e4 | 7301 | switch (action) { |
1da177e4 | 7302 | case CPU_DOWN_PREPARE: |
8bb78442 | 7303 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 7304 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
7305 | return NOTIFY_OK; |
7306 | ||
1da177e4 | 7307 | case CPU_DOWN_FAILED: |
8bb78442 | 7308 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 7309 | case CPU_ONLINE: |
8bb78442 | 7310 | case CPU_ONLINE_FROZEN: |
7def2be1 | 7311 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
7312 | return NOTIFY_OK; |
7313 | ||
1da177e4 LT |
7314 | default: |
7315 | return NOTIFY_DONE; | |
7316 | } | |
1da177e4 | 7317 | } |
1da177e4 LT |
7318 | |
7319 | void __init sched_init_smp(void) | |
7320 | { | |
dcc30a35 RR |
7321 | cpumask_var_t non_isolated_cpus; |
7322 | ||
7323 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 7324 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 7325 | |
434d53b0 MT |
7326 | #if defined(CONFIG_NUMA) |
7327 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
7328 | GFP_KERNEL); | |
7329 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
7330 | #endif | |
95402b38 | 7331 | get_online_cpus(); |
712555ee | 7332 | mutex_lock(&sched_domains_mutex); |
6ad4c188 | 7333 | arch_init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
7334 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
7335 | if (cpumask_empty(non_isolated_cpus)) | |
7336 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7337 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 7338 | put_online_cpus(); |
e761b772 MK |
7339 | |
7340 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
7341 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
7342 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
7343 | #endif |
7344 | ||
7345 | /* RT runtime code needs to handle some hotplug events */ | |
7346 | hotcpu_notifier(update_runtime, 0); | |
7347 | ||
b328ca18 | 7348 | init_hrtick(); |
5c1e1767 NP |
7349 | |
7350 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 7351 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 7352 | BUG(); |
19978ca6 | 7353 | sched_init_granularity(); |
dcc30a35 | 7354 | free_cpumask_var(non_isolated_cpus); |
4212823f | 7355 | |
0e3900e6 | 7356 | init_sched_rt_class(); |
1da177e4 LT |
7357 | } |
7358 | #else | |
7359 | void __init sched_init_smp(void) | |
7360 | { | |
19978ca6 | 7361 | sched_init_granularity(); |
1da177e4 LT |
7362 | } |
7363 | #endif /* CONFIG_SMP */ | |
7364 | ||
cd1bb94b AB |
7365 | const_debug unsigned int sysctl_timer_migration = 1; |
7366 | ||
1da177e4 LT |
7367 | int in_sched_functions(unsigned long addr) |
7368 | { | |
1da177e4 LT |
7369 | return in_lock_functions(addr) || |
7370 | (addr >= (unsigned long)__sched_text_start | |
7371 | && addr < (unsigned long)__sched_text_end); | |
7372 | } | |
7373 | ||
a9957449 | 7374 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
7375 | { |
7376 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 7377 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
7378 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7379 | cfs_rq->rq = rq; | |
7380 | #endif | |
67e9fb2a | 7381 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
7382 | } |
7383 | ||
fa85ae24 PZ |
7384 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
7385 | { | |
7386 | struct rt_prio_array *array; | |
7387 | int i; | |
7388 | ||
7389 | array = &rt_rq->active; | |
7390 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
7391 | INIT_LIST_HEAD(array->queue + i); | |
7392 | __clear_bit(i, array->bitmap); | |
7393 | } | |
7394 | /* delimiter for bitsearch: */ | |
7395 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
7396 | ||
052f1dc7 | 7397 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 7398 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 7399 | #ifdef CONFIG_SMP |
e864c499 | 7400 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 7401 | #endif |
48d5e258 | 7402 | #endif |
fa85ae24 PZ |
7403 | #ifdef CONFIG_SMP |
7404 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 7405 | rt_rq->overloaded = 0; |
05fa785c | 7406 | plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
7407 | #endif |
7408 | ||
7409 | rt_rq->rt_time = 0; | |
7410 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 7411 | rt_rq->rt_runtime = 0; |
0986b11b | 7412 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
6f505b16 | 7413 | |
052f1dc7 | 7414 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 7415 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
7416 | rt_rq->rq = rq; |
7417 | #endif | |
fa85ae24 PZ |
7418 | } |
7419 | ||
6f505b16 | 7420 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
7421 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
7422 | struct sched_entity *se, int cpu, int add, | |
7423 | struct sched_entity *parent) | |
6f505b16 | 7424 | { |
ec7dc8ac | 7425 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
7426 | tg->cfs_rq[cpu] = cfs_rq; |
7427 | init_cfs_rq(cfs_rq, rq); | |
7428 | cfs_rq->tg = tg; | |
7429 | if (add) | |
7430 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
7431 | ||
7432 | tg->se[cpu] = se; | |
354d60c2 DG |
7433 | /* se could be NULL for init_task_group */ |
7434 | if (!se) | |
7435 | return; | |
7436 | ||
ec7dc8ac DG |
7437 | if (!parent) |
7438 | se->cfs_rq = &rq->cfs; | |
7439 | else | |
7440 | se->cfs_rq = parent->my_q; | |
7441 | ||
6f505b16 PZ |
7442 | se->my_q = cfs_rq; |
7443 | se->load.weight = tg->shares; | |
e05510d0 | 7444 | se->load.inv_weight = 0; |
ec7dc8ac | 7445 | se->parent = parent; |
6f505b16 | 7446 | } |
052f1dc7 | 7447 | #endif |
6f505b16 | 7448 | |
052f1dc7 | 7449 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
7450 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
7451 | struct sched_rt_entity *rt_se, int cpu, int add, | |
7452 | struct sched_rt_entity *parent) | |
6f505b16 | 7453 | { |
ec7dc8ac DG |
7454 | struct rq *rq = cpu_rq(cpu); |
7455 | ||
6f505b16 PZ |
7456 | tg->rt_rq[cpu] = rt_rq; |
7457 | init_rt_rq(rt_rq, rq); | |
7458 | rt_rq->tg = tg; | |
ac086bc2 | 7459 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
7460 | if (add) |
7461 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
7462 | ||
7463 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
7464 | if (!rt_se) |
7465 | return; | |
7466 | ||
ec7dc8ac DG |
7467 | if (!parent) |
7468 | rt_se->rt_rq = &rq->rt; | |
7469 | else | |
7470 | rt_se->rt_rq = parent->my_q; | |
7471 | ||
6f505b16 | 7472 | rt_se->my_q = rt_rq; |
ec7dc8ac | 7473 | rt_se->parent = parent; |
6f505b16 PZ |
7474 | INIT_LIST_HEAD(&rt_se->run_list); |
7475 | } | |
7476 | #endif | |
7477 | ||
1da177e4 LT |
7478 | void __init sched_init(void) |
7479 | { | |
dd41f596 | 7480 | int i, j; |
434d53b0 MT |
7481 | unsigned long alloc_size = 0, ptr; |
7482 | ||
7483 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7484 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
7485 | #endif | |
7486 | #ifdef CONFIG_RT_GROUP_SCHED | |
7487 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7488 | #endif |
df7c8e84 | 7489 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 7490 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 7491 | #endif |
434d53b0 | 7492 | if (alloc_size) { |
36b7b6d4 | 7493 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
7494 | |
7495 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7496 | init_task_group.se = (struct sched_entity **)ptr; | |
7497 | ptr += nr_cpu_ids * sizeof(void **); | |
7498 | ||
7499 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
7500 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7501 | |
6d6bc0ad | 7502 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 MT |
7503 | #ifdef CONFIG_RT_GROUP_SCHED |
7504 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
7505 | ptr += nr_cpu_ids * sizeof(void **); | |
7506 | ||
7507 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
7508 | ptr += nr_cpu_ids * sizeof(void **); |
7509 | ||
6d6bc0ad | 7510 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
7511 | #ifdef CONFIG_CPUMASK_OFFSTACK |
7512 | for_each_possible_cpu(i) { | |
7513 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
7514 | ptr += cpumask_size(); | |
7515 | } | |
7516 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 7517 | } |
dd41f596 | 7518 | |
57d885fe GH |
7519 | #ifdef CONFIG_SMP |
7520 | init_defrootdomain(); | |
7521 | #endif | |
7522 | ||
d0b27fa7 PZ |
7523 | init_rt_bandwidth(&def_rt_bandwidth, |
7524 | global_rt_period(), global_rt_runtime()); | |
7525 | ||
7526 | #ifdef CONFIG_RT_GROUP_SCHED | |
7527 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
7528 | global_rt_period(), global_rt_runtime()); | |
6d6bc0ad | 7529 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7530 | |
7c941438 | 7531 | #ifdef CONFIG_CGROUP_SCHED |
6f505b16 | 7532 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
7533 | INIT_LIST_HEAD(&init_task_group.children); |
7534 | ||
7c941438 | 7535 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 7536 | |
4a6cc4bd JK |
7537 | #if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP |
7538 | update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), | |
7539 | __alignof__(unsigned long)); | |
7540 | #endif | |
0a945022 | 7541 | for_each_possible_cpu(i) { |
70b97a7f | 7542 | struct rq *rq; |
1da177e4 LT |
7543 | |
7544 | rq = cpu_rq(i); | |
05fa785c | 7545 | raw_spin_lock_init(&rq->lock); |
7897986b | 7546 | rq->nr_running = 0; |
dce48a84 TG |
7547 | rq->calc_load_active = 0; |
7548 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 7549 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 7550 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 7551 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 7552 | init_task_group.shares = init_task_group_load; |
6f505b16 | 7553 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
7554 | #ifdef CONFIG_CGROUP_SCHED |
7555 | /* | |
7556 | * How much cpu bandwidth does init_task_group get? | |
7557 | * | |
7558 | * In case of task-groups formed thr' the cgroup filesystem, it | |
7559 | * gets 100% of the cpu resources in the system. This overall | |
7560 | * system cpu resource is divided among the tasks of | |
7561 | * init_task_group and its child task-groups in a fair manner, | |
7562 | * based on each entity's (task or task-group's) weight | |
7563 | * (se->load.weight). | |
7564 | * | |
7565 | * In other words, if init_task_group has 10 tasks of weight | |
7566 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
7567 | * then A0's share of the cpu resource is: | |
7568 | * | |
0d905bca | 7569 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
7570 | * |
7571 | * We achieve this by letting init_task_group's tasks sit | |
7572 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
7573 | */ | |
ec7dc8ac | 7574 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
052f1dc7 | 7575 | #endif |
354d60c2 DG |
7576 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
7577 | ||
7578 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 7579 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 7580 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 7581 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 7582 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 7583 | #endif |
dd41f596 | 7584 | #endif |
1da177e4 | 7585 | |
dd41f596 IM |
7586 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
7587 | rq->cpu_load[j] = 0; | |
1da177e4 | 7588 | #ifdef CONFIG_SMP |
41c7ce9a | 7589 | rq->sd = NULL; |
57d885fe | 7590 | rq->rd = NULL; |
3f029d3c | 7591 | rq->post_schedule = 0; |
1da177e4 | 7592 | rq->active_balance = 0; |
dd41f596 | 7593 | rq->next_balance = jiffies; |
1da177e4 | 7594 | rq->push_cpu = 0; |
0a2966b4 | 7595 | rq->cpu = i; |
1f11eb6a | 7596 | rq->online = 0; |
eae0c9df MG |
7597 | rq->idle_stamp = 0; |
7598 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
dc938520 | 7599 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 7600 | #endif |
8f4d37ec | 7601 | init_rq_hrtick(rq); |
1da177e4 | 7602 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
7603 | } |
7604 | ||
2dd73a4f | 7605 | set_load_weight(&init_task); |
b50f60ce | 7606 | |
e107be36 AK |
7607 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7608 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7609 | #endif | |
7610 | ||
c9819f45 | 7611 | #ifdef CONFIG_SMP |
962cf36c | 7612 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
7613 | #endif |
7614 | ||
b50f60ce | 7615 | #ifdef CONFIG_RT_MUTEXES |
1d615482 | 7616 | plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); |
b50f60ce HC |
7617 | #endif |
7618 | ||
1da177e4 LT |
7619 | /* |
7620 | * The boot idle thread does lazy MMU switching as well: | |
7621 | */ | |
7622 | atomic_inc(&init_mm.mm_count); | |
7623 | enter_lazy_tlb(&init_mm, current); | |
7624 | ||
7625 | /* | |
7626 | * Make us the idle thread. Technically, schedule() should not be | |
7627 | * called from this thread, however somewhere below it might be, | |
7628 | * but because we are the idle thread, we just pick up running again | |
7629 | * when this runqueue becomes "idle". | |
7630 | */ | |
7631 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7632 | |
7633 | calc_load_update = jiffies + LOAD_FREQ; | |
7634 | ||
dd41f596 IM |
7635 | /* |
7636 | * During early bootup we pretend to be a normal task: | |
7637 | */ | |
7638 | current->sched_class = &fair_sched_class; | |
6892b75e | 7639 | |
6a7b3dc3 | 7640 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 7641 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 7642 | #ifdef CONFIG_SMP |
7d1e6a9b | 7643 | #ifdef CONFIG_NO_HZ |
49557e62 | 7644 | zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); |
4bdddf8f | 7645 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); |
7d1e6a9b | 7646 | #endif |
bdddd296 RR |
7647 | /* May be allocated at isolcpus cmdline parse time */ |
7648 | if (cpu_isolated_map == NULL) | |
7649 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 7650 | #endif /* SMP */ |
6a7b3dc3 | 7651 | |
cdd6c482 | 7652 | perf_event_init(); |
0d905bca | 7653 | |
6892b75e | 7654 | scheduler_running = 1; |
1da177e4 LT |
7655 | } |
7656 | ||
7657 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
7658 | static inline int preempt_count_equals(int preempt_offset) |
7659 | { | |
234da7bc | 7660 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 FW |
7661 | |
7662 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
7663 | } | |
7664 | ||
d894837f | 7665 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7666 | { |
48f24c4d | 7667 | #ifdef in_atomic |
1da177e4 LT |
7668 | static unsigned long prev_jiffy; /* ratelimiting */ |
7669 | ||
e4aafea2 FW |
7670 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
7671 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
7672 | return; |
7673 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7674 | return; | |
7675 | prev_jiffy = jiffies; | |
7676 | ||
3df0fc5b PZ |
7677 | printk(KERN_ERR |
7678 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7679 | file, line); | |
7680 | printk(KERN_ERR | |
7681 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7682 | in_atomic(), irqs_disabled(), | |
7683 | current->pid, current->comm); | |
aef745fc IM |
7684 | |
7685 | debug_show_held_locks(current); | |
7686 | if (irqs_disabled()) | |
7687 | print_irqtrace_events(current); | |
7688 | dump_stack(); | |
1da177e4 LT |
7689 | #endif |
7690 | } | |
7691 | EXPORT_SYMBOL(__might_sleep); | |
7692 | #endif | |
7693 | ||
7694 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7695 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7696 | { | |
7697 | int on_rq; | |
3e51f33f | 7698 | |
3a5e4dc1 AK |
7699 | on_rq = p->se.on_rq; |
7700 | if (on_rq) | |
7701 | deactivate_task(rq, p, 0); | |
7702 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
7703 | if (on_rq) { | |
7704 | activate_task(rq, p, 0); | |
7705 | resched_task(rq->curr); | |
7706 | } | |
7707 | } | |
7708 | ||
1da177e4 LT |
7709 | void normalize_rt_tasks(void) |
7710 | { | |
a0f98a1c | 7711 | struct task_struct *g, *p; |
1da177e4 | 7712 | unsigned long flags; |
70b97a7f | 7713 | struct rq *rq; |
1da177e4 | 7714 | |
4cf5d77a | 7715 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 7716 | do_each_thread(g, p) { |
178be793 IM |
7717 | /* |
7718 | * Only normalize user tasks: | |
7719 | */ | |
7720 | if (!p->mm) | |
7721 | continue; | |
7722 | ||
6cfb0d5d | 7723 | p->se.exec_start = 0; |
6cfb0d5d | 7724 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7725 | p->se.statistics.wait_start = 0; |
7726 | p->se.statistics.sleep_start = 0; | |
7727 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7728 | #endif |
dd41f596 IM |
7729 | |
7730 | if (!rt_task(p)) { | |
7731 | /* | |
7732 | * Renice negative nice level userspace | |
7733 | * tasks back to 0: | |
7734 | */ | |
7735 | if (TASK_NICE(p) < 0 && p->mm) | |
7736 | set_user_nice(p, 0); | |
1da177e4 | 7737 | continue; |
dd41f596 | 7738 | } |
1da177e4 | 7739 | |
1d615482 | 7740 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7741 | rq = __task_rq_lock(p); |
1da177e4 | 7742 | |
178be793 | 7743 | normalize_task(rq, p); |
3a5e4dc1 | 7744 | |
b29739f9 | 7745 | __task_rq_unlock(rq); |
1d615482 | 7746 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7747 | } while_each_thread(g, p); |
7748 | ||
4cf5d77a | 7749 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7750 | } |
7751 | ||
7752 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7753 | |
67fc4e0c | 7754 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7755 | /* |
67fc4e0c | 7756 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7757 | * |
7758 | * They can only be called when the whole system has been | |
7759 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7760 | * activity can take place. Using them for anything else would | |
7761 | * be a serious bug, and as a result, they aren't even visible | |
7762 | * under any other configuration. | |
7763 | */ | |
7764 | ||
7765 | /** | |
7766 | * curr_task - return the current task for a given cpu. | |
7767 | * @cpu: the processor in question. | |
7768 | * | |
7769 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7770 | */ | |
36c8b586 | 7771 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7772 | { |
7773 | return cpu_curr(cpu); | |
7774 | } | |
7775 | ||
67fc4e0c JW |
7776 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7777 | ||
7778 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7779 | /** |
7780 | * set_curr_task - set the current task for a given cpu. | |
7781 | * @cpu: the processor in question. | |
7782 | * @p: the task pointer to set. | |
7783 | * | |
7784 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7785 | * are serviced on a separate stack. It allows the architecture to switch the |
7786 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7787 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7788 | * and caller must save the original value of the current task (see | |
7789 | * curr_task() above) and restore that value before reenabling interrupts and | |
7790 | * re-starting the system. | |
7791 | * | |
7792 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7793 | */ | |
36c8b586 | 7794 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7795 | { |
7796 | cpu_curr(cpu) = p; | |
7797 | } | |
7798 | ||
7799 | #endif | |
29f59db3 | 7800 | |
bccbe08a PZ |
7801 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7802 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
7803 | { |
7804 | int i; | |
7805 | ||
7806 | for_each_possible_cpu(i) { | |
7807 | if (tg->cfs_rq) | |
7808 | kfree(tg->cfs_rq[i]); | |
7809 | if (tg->se) | |
7810 | kfree(tg->se[i]); | |
6f505b16 PZ |
7811 | } |
7812 | ||
7813 | kfree(tg->cfs_rq); | |
7814 | kfree(tg->se); | |
6f505b16 PZ |
7815 | } |
7816 | ||
ec7dc8ac DG |
7817 | static |
7818 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 7819 | { |
29f59db3 | 7820 | struct cfs_rq *cfs_rq; |
eab17229 | 7821 | struct sched_entity *se; |
9b5b7751 | 7822 | struct rq *rq; |
29f59db3 SV |
7823 | int i; |
7824 | ||
434d53b0 | 7825 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
7826 | if (!tg->cfs_rq) |
7827 | goto err; | |
434d53b0 | 7828 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
7829 | if (!tg->se) |
7830 | goto err; | |
052f1dc7 PZ |
7831 | |
7832 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
7833 | |
7834 | for_each_possible_cpu(i) { | |
9b5b7751 | 7835 | rq = cpu_rq(i); |
29f59db3 | 7836 | |
eab17229 LZ |
7837 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
7838 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
7839 | if (!cfs_rq) |
7840 | goto err; | |
7841 | ||
eab17229 LZ |
7842 | se = kzalloc_node(sizeof(struct sched_entity), |
7843 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 7844 | if (!se) |
dfc12eb2 | 7845 | goto err_free_rq; |
29f59db3 | 7846 | |
eab17229 | 7847 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
7848 | } |
7849 | ||
7850 | return 1; | |
7851 | ||
dfc12eb2 PC |
7852 | err_free_rq: |
7853 | kfree(cfs_rq); | |
bccbe08a PZ |
7854 | err: |
7855 | return 0; | |
7856 | } | |
7857 | ||
7858 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
7859 | { | |
7860 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
7861 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
7862 | } | |
7863 | ||
7864 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
7865 | { | |
7866 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
7867 | } | |
6d6bc0ad | 7868 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
7869 | static inline void free_fair_sched_group(struct task_group *tg) |
7870 | { | |
7871 | } | |
7872 | ||
ec7dc8ac DG |
7873 | static inline |
7874 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
7875 | { |
7876 | return 1; | |
7877 | } | |
7878 | ||
7879 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
7880 | { | |
7881 | } | |
7882 | ||
7883 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
7884 | { | |
7885 | } | |
6d6bc0ad | 7886 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
7887 | |
7888 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
7889 | static void free_rt_sched_group(struct task_group *tg) |
7890 | { | |
7891 | int i; | |
7892 | ||
d0b27fa7 PZ |
7893 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
7894 | ||
bccbe08a PZ |
7895 | for_each_possible_cpu(i) { |
7896 | if (tg->rt_rq) | |
7897 | kfree(tg->rt_rq[i]); | |
7898 | if (tg->rt_se) | |
7899 | kfree(tg->rt_se[i]); | |
7900 | } | |
7901 | ||
7902 | kfree(tg->rt_rq); | |
7903 | kfree(tg->rt_se); | |
7904 | } | |
7905 | ||
ec7dc8ac DG |
7906 | static |
7907 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
7908 | { |
7909 | struct rt_rq *rt_rq; | |
eab17229 | 7910 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
7911 | struct rq *rq; |
7912 | int i; | |
7913 | ||
434d53b0 | 7914 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
7915 | if (!tg->rt_rq) |
7916 | goto err; | |
434d53b0 | 7917 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
7918 | if (!tg->rt_se) |
7919 | goto err; | |
7920 | ||
d0b27fa7 PZ |
7921 | init_rt_bandwidth(&tg->rt_bandwidth, |
7922 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
7923 | |
7924 | for_each_possible_cpu(i) { | |
7925 | rq = cpu_rq(i); | |
7926 | ||
eab17229 LZ |
7927 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
7928 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
7929 | if (!rt_rq) |
7930 | goto err; | |
29f59db3 | 7931 | |
eab17229 LZ |
7932 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
7933 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 7934 | if (!rt_se) |
dfc12eb2 | 7935 | goto err_free_rq; |
29f59db3 | 7936 | |
eab17229 | 7937 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
7938 | } |
7939 | ||
bccbe08a PZ |
7940 | return 1; |
7941 | ||
dfc12eb2 PC |
7942 | err_free_rq: |
7943 | kfree(rt_rq); | |
bccbe08a PZ |
7944 | err: |
7945 | return 0; | |
7946 | } | |
7947 | ||
7948 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
7949 | { | |
7950 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
7951 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
7952 | } | |
7953 | ||
7954 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
7955 | { | |
7956 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
7957 | } | |
6d6bc0ad | 7958 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
7959 | static inline void free_rt_sched_group(struct task_group *tg) |
7960 | { | |
7961 | } | |
7962 | ||
ec7dc8ac DG |
7963 | static inline |
7964 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
7965 | { |
7966 | return 1; | |
7967 | } | |
7968 | ||
7969 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
7970 | { | |
7971 | } | |
7972 | ||
7973 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
7974 | { | |
7975 | } | |
6d6bc0ad | 7976 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 7977 | |
7c941438 | 7978 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
7979 | static void free_sched_group(struct task_group *tg) |
7980 | { | |
7981 | free_fair_sched_group(tg); | |
7982 | free_rt_sched_group(tg); | |
7983 | kfree(tg); | |
7984 | } | |
7985 | ||
7986 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 7987 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
7988 | { |
7989 | struct task_group *tg; | |
7990 | unsigned long flags; | |
7991 | int i; | |
7992 | ||
7993 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
7994 | if (!tg) | |
7995 | return ERR_PTR(-ENOMEM); | |
7996 | ||
ec7dc8ac | 7997 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
7998 | goto err; |
7999 | ||
ec7dc8ac | 8000 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8001 | goto err; |
8002 | ||
8ed36996 | 8003 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8004 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8005 | register_fair_sched_group(tg, i); |
8006 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8007 | } |
6f505b16 | 8008 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8009 | |
8010 | WARN_ON(!parent); /* root should already exist */ | |
8011 | ||
8012 | tg->parent = parent; | |
f473aa5e | 8013 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8014 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8015 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8016 | |
9b5b7751 | 8017 | return tg; |
29f59db3 SV |
8018 | |
8019 | err: | |
6f505b16 | 8020 | free_sched_group(tg); |
29f59db3 SV |
8021 | return ERR_PTR(-ENOMEM); |
8022 | } | |
8023 | ||
9b5b7751 | 8024 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8025 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8026 | { |
29f59db3 | 8027 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8028 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8029 | } |
8030 | ||
9b5b7751 | 8031 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8032 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8033 | { |
8ed36996 | 8034 | unsigned long flags; |
9b5b7751 | 8035 | int i; |
29f59db3 | 8036 | |
8ed36996 | 8037 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8038 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8039 | unregister_fair_sched_group(tg, i); |
8040 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8041 | } |
6f505b16 | 8042 | list_del_rcu(&tg->list); |
f473aa5e | 8043 | list_del_rcu(&tg->siblings); |
8ed36996 | 8044 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8045 | |
9b5b7751 | 8046 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8047 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8048 | } |
8049 | ||
9b5b7751 | 8050 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8051 | * The caller of this function should have put the task in its new group |
8052 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8053 | * reflect its new group. | |
9b5b7751 SV |
8054 | */ |
8055 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8056 | { |
8057 | int on_rq, running; | |
8058 | unsigned long flags; | |
8059 | struct rq *rq; | |
8060 | ||
8061 | rq = task_rq_lock(tsk, &flags); | |
8062 | ||
051a1d1a | 8063 | running = task_current(rq, tsk); |
29f59db3 SV |
8064 | on_rq = tsk->se.on_rq; |
8065 | ||
0e1f3483 | 8066 | if (on_rq) |
29f59db3 | 8067 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8068 | if (unlikely(running)) |
8069 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8070 | |
6f505b16 | 8071 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 8072 | |
810b3817 PZ |
8073 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8074 | if (tsk->sched_class->moved_group) | |
88ec22d3 | 8075 | tsk->sched_class->moved_group(tsk, on_rq); |
810b3817 PZ |
8076 | #endif |
8077 | ||
0e1f3483 HS |
8078 | if (unlikely(running)) |
8079 | tsk->sched_class->set_curr_task(rq); | |
8080 | if (on_rq) | |
371fd7e7 | 8081 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8082 | |
29f59db3 SV |
8083 | task_rq_unlock(rq, &flags); |
8084 | } | |
7c941438 | 8085 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8086 | |
052f1dc7 | 8087 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 8088 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
8089 | { |
8090 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
8091 | int on_rq; |
8092 | ||
29f59db3 | 8093 | on_rq = se->on_rq; |
62fb1851 | 8094 | if (on_rq) |
29f59db3 SV |
8095 | dequeue_entity(cfs_rq, se, 0); |
8096 | ||
8097 | se->load.weight = shares; | |
e05510d0 | 8098 | se->load.inv_weight = 0; |
29f59db3 | 8099 | |
62fb1851 | 8100 | if (on_rq) |
29f59db3 | 8101 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 8102 | } |
62fb1851 | 8103 | |
c09595f6 PZ |
8104 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
8105 | { | |
8106 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
8107 | struct rq *rq = cfs_rq->rq; | |
8108 | unsigned long flags; | |
8109 | ||
05fa785c | 8110 | raw_spin_lock_irqsave(&rq->lock, flags); |
c09595f6 | 8111 | __set_se_shares(se, shares); |
05fa785c | 8112 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
29f59db3 SV |
8113 | } |
8114 | ||
8ed36996 PZ |
8115 | static DEFINE_MUTEX(shares_mutex); |
8116 | ||
4cf86d77 | 8117 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8118 | { |
8119 | int i; | |
8ed36996 | 8120 | unsigned long flags; |
c61935fd | 8121 | |
ec7dc8ac DG |
8122 | /* |
8123 | * We can't change the weight of the root cgroup. | |
8124 | */ | |
8125 | if (!tg->se[0]) | |
8126 | return -EINVAL; | |
8127 | ||
18d95a28 PZ |
8128 | if (shares < MIN_SHARES) |
8129 | shares = MIN_SHARES; | |
cb4ad1ff MX |
8130 | else if (shares > MAX_SHARES) |
8131 | shares = MAX_SHARES; | |
62fb1851 | 8132 | |
8ed36996 | 8133 | mutex_lock(&shares_mutex); |
9b5b7751 | 8134 | if (tg->shares == shares) |
5cb350ba | 8135 | goto done; |
29f59db3 | 8136 | |
8ed36996 | 8137 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8138 | for_each_possible_cpu(i) |
8139 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 8140 | list_del_rcu(&tg->siblings); |
8ed36996 | 8141 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
8142 | |
8143 | /* wait for any ongoing reference to this group to finish */ | |
8144 | synchronize_sched(); | |
8145 | ||
8146 | /* | |
8147 | * Now we are free to modify the group's share on each cpu | |
8148 | * w/o tripping rebalance_share or load_balance_fair. | |
8149 | */ | |
9b5b7751 | 8150 | tg->shares = shares; |
c09595f6 PZ |
8151 | for_each_possible_cpu(i) { |
8152 | /* | |
8153 | * force a rebalance | |
8154 | */ | |
8155 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 8156 | set_se_shares(tg->se[i], shares); |
c09595f6 | 8157 | } |
29f59db3 | 8158 | |
6b2d7700 SV |
8159 | /* |
8160 | * Enable load balance activity on this group, by inserting it back on | |
8161 | * each cpu's rq->leaf_cfs_rq_list. | |
8162 | */ | |
8ed36996 | 8163 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8164 | for_each_possible_cpu(i) |
8165 | register_fair_sched_group(tg, i); | |
f473aa5e | 8166 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 8167 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 8168 | done: |
8ed36996 | 8169 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8170 | return 0; |
29f59db3 SV |
8171 | } |
8172 | ||
5cb350ba DG |
8173 | unsigned long sched_group_shares(struct task_group *tg) |
8174 | { | |
8175 | return tg->shares; | |
8176 | } | |
052f1dc7 | 8177 | #endif |
5cb350ba | 8178 | |
052f1dc7 | 8179 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8180 | /* |
9f0c1e56 | 8181 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 8182 | */ |
9f0c1e56 PZ |
8183 | static DEFINE_MUTEX(rt_constraints_mutex); |
8184 | ||
8185 | static unsigned long to_ratio(u64 period, u64 runtime) | |
8186 | { | |
8187 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8188 | return 1ULL << 20; |
9f0c1e56 | 8189 | |
9a7e0b18 | 8190 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
8191 | } |
8192 | ||
9a7e0b18 PZ |
8193 | /* Must be called with tasklist_lock held */ |
8194 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8195 | { |
9a7e0b18 | 8196 | struct task_struct *g, *p; |
b40b2e8e | 8197 | |
9a7e0b18 PZ |
8198 | do_each_thread(g, p) { |
8199 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8200 | return 1; | |
8201 | } while_each_thread(g, p); | |
b40b2e8e | 8202 | |
9a7e0b18 PZ |
8203 | return 0; |
8204 | } | |
b40b2e8e | 8205 | |
9a7e0b18 PZ |
8206 | struct rt_schedulable_data { |
8207 | struct task_group *tg; | |
8208 | u64 rt_period; | |
8209 | u64 rt_runtime; | |
8210 | }; | |
b40b2e8e | 8211 | |
9a7e0b18 PZ |
8212 | static int tg_schedulable(struct task_group *tg, void *data) |
8213 | { | |
8214 | struct rt_schedulable_data *d = data; | |
8215 | struct task_group *child; | |
8216 | unsigned long total, sum = 0; | |
8217 | u64 period, runtime; | |
b40b2e8e | 8218 | |
9a7e0b18 PZ |
8219 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8220 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8221 | |
9a7e0b18 PZ |
8222 | if (tg == d->tg) { |
8223 | period = d->rt_period; | |
8224 | runtime = d->rt_runtime; | |
b40b2e8e | 8225 | } |
b40b2e8e | 8226 | |
4653f803 PZ |
8227 | /* |
8228 | * Cannot have more runtime than the period. | |
8229 | */ | |
8230 | if (runtime > period && runtime != RUNTIME_INF) | |
8231 | return -EINVAL; | |
6f505b16 | 8232 | |
4653f803 PZ |
8233 | /* |
8234 | * Ensure we don't starve existing RT tasks. | |
8235 | */ | |
9a7e0b18 PZ |
8236 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8237 | return -EBUSY; | |
6f505b16 | 8238 | |
9a7e0b18 | 8239 | total = to_ratio(period, runtime); |
6f505b16 | 8240 | |
4653f803 PZ |
8241 | /* |
8242 | * Nobody can have more than the global setting allows. | |
8243 | */ | |
8244 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8245 | return -EINVAL; | |
6f505b16 | 8246 | |
4653f803 PZ |
8247 | /* |
8248 | * The sum of our children's runtime should not exceed our own. | |
8249 | */ | |
9a7e0b18 PZ |
8250 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8251 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8252 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8253 | |
9a7e0b18 PZ |
8254 | if (child == d->tg) { |
8255 | period = d->rt_period; | |
8256 | runtime = d->rt_runtime; | |
8257 | } | |
6f505b16 | 8258 | |
9a7e0b18 | 8259 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8260 | } |
6f505b16 | 8261 | |
9a7e0b18 PZ |
8262 | if (sum > total) |
8263 | return -EINVAL; | |
8264 | ||
8265 | return 0; | |
6f505b16 PZ |
8266 | } |
8267 | ||
9a7e0b18 | 8268 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8269 | { |
9a7e0b18 PZ |
8270 | struct rt_schedulable_data data = { |
8271 | .tg = tg, | |
8272 | .rt_period = period, | |
8273 | .rt_runtime = runtime, | |
8274 | }; | |
8275 | ||
8276 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
8277 | } |
8278 | ||
d0b27fa7 PZ |
8279 | static int tg_set_bandwidth(struct task_group *tg, |
8280 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 8281 | { |
ac086bc2 | 8282 | int i, err = 0; |
9f0c1e56 | 8283 | |
9f0c1e56 | 8284 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8285 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8286 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8287 | if (err) | |
9f0c1e56 | 8288 | goto unlock; |
ac086bc2 | 8289 | |
0986b11b | 8290 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8291 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8292 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8293 | |
8294 | for_each_possible_cpu(i) { | |
8295 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8296 | ||
0986b11b | 8297 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8298 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8299 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8300 | } |
0986b11b | 8301 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
9f0c1e56 | 8302 | unlock: |
521f1a24 | 8303 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8304 | mutex_unlock(&rt_constraints_mutex); |
8305 | ||
8306 | return err; | |
6f505b16 PZ |
8307 | } |
8308 | ||
d0b27fa7 PZ |
8309 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8310 | { | |
8311 | u64 rt_runtime, rt_period; | |
8312 | ||
8313 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8314 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8315 | if (rt_runtime_us < 0) | |
8316 | rt_runtime = RUNTIME_INF; | |
8317 | ||
8318 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
8319 | } | |
8320 | ||
9f0c1e56 PZ |
8321 | long sched_group_rt_runtime(struct task_group *tg) |
8322 | { | |
8323 | u64 rt_runtime_us; | |
8324 | ||
d0b27fa7 | 8325 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8326 | return -1; |
8327 | ||
d0b27fa7 | 8328 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8329 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8330 | return rt_runtime_us; | |
8331 | } | |
d0b27fa7 PZ |
8332 | |
8333 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8334 | { | |
8335 | u64 rt_runtime, rt_period; | |
8336 | ||
8337 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8338 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8339 | ||
619b0488 R |
8340 | if (rt_period == 0) |
8341 | return -EINVAL; | |
8342 | ||
d0b27fa7 PZ |
8343 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
8344 | } | |
8345 | ||
8346 | long sched_group_rt_period(struct task_group *tg) | |
8347 | { | |
8348 | u64 rt_period_us; | |
8349 | ||
8350 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8351 | do_div(rt_period_us, NSEC_PER_USEC); | |
8352 | return rt_period_us; | |
8353 | } | |
8354 | ||
8355 | static int sched_rt_global_constraints(void) | |
8356 | { | |
4653f803 | 8357 | u64 runtime, period; |
d0b27fa7 PZ |
8358 | int ret = 0; |
8359 | ||
ec5d4989 HS |
8360 | if (sysctl_sched_rt_period <= 0) |
8361 | return -EINVAL; | |
8362 | ||
4653f803 PZ |
8363 | runtime = global_rt_runtime(); |
8364 | period = global_rt_period(); | |
8365 | ||
8366 | /* | |
8367 | * Sanity check on the sysctl variables. | |
8368 | */ | |
8369 | if (runtime > period && runtime != RUNTIME_INF) | |
8370 | return -EINVAL; | |
10b612f4 | 8371 | |
d0b27fa7 | 8372 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 8373 | read_lock(&tasklist_lock); |
4653f803 | 8374 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 8375 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
8376 | mutex_unlock(&rt_constraints_mutex); |
8377 | ||
8378 | return ret; | |
8379 | } | |
54e99124 DG |
8380 | |
8381 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
8382 | { | |
8383 | /* Don't accept realtime tasks when there is no way for them to run */ | |
8384 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
8385 | return 0; | |
8386 | ||
8387 | return 1; | |
8388 | } | |
8389 | ||
6d6bc0ad | 8390 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8391 | static int sched_rt_global_constraints(void) |
8392 | { | |
ac086bc2 PZ |
8393 | unsigned long flags; |
8394 | int i; | |
8395 | ||
ec5d4989 HS |
8396 | if (sysctl_sched_rt_period <= 0) |
8397 | return -EINVAL; | |
8398 | ||
60aa605d PZ |
8399 | /* |
8400 | * There's always some RT tasks in the root group | |
8401 | * -- migration, kstopmachine etc.. | |
8402 | */ | |
8403 | if (sysctl_sched_rt_runtime == 0) | |
8404 | return -EBUSY; | |
8405 | ||
0986b11b | 8406 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
8407 | for_each_possible_cpu(i) { |
8408 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
8409 | ||
0986b11b | 8410 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8411 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 8412 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8413 | } |
0986b11b | 8414 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 8415 | |
d0b27fa7 PZ |
8416 | return 0; |
8417 | } | |
6d6bc0ad | 8418 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8419 | |
8420 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 8421 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
8422 | loff_t *ppos) |
8423 | { | |
8424 | int ret; | |
8425 | int old_period, old_runtime; | |
8426 | static DEFINE_MUTEX(mutex); | |
8427 | ||
8428 | mutex_lock(&mutex); | |
8429 | old_period = sysctl_sched_rt_period; | |
8430 | old_runtime = sysctl_sched_rt_runtime; | |
8431 | ||
8d65af78 | 8432 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
8433 | |
8434 | if (!ret && write) { | |
8435 | ret = sched_rt_global_constraints(); | |
8436 | if (ret) { | |
8437 | sysctl_sched_rt_period = old_period; | |
8438 | sysctl_sched_rt_runtime = old_runtime; | |
8439 | } else { | |
8440 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
8441 | def_rt_bandwidth.rt_period = | |
8442 | ns_to_ktime(global_rt_period()); | |
8443 | } | |
8444 | } | |
8445 | mutex_unlock(&mutex); | |
8446 | ||
8447 | return ret; | |
8448 | } | |
68318b8e | 8449 | |
052f1dc7 | 8450 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
8451 | |
8452 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 8453 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 8454 | { |
2b01dfe3 PM |
8455 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
8456 | struct task_group, css); | |
68318b8e SV |
8457 | } |
8458 | ||
8459 | static struct cgroup_subsys_state * | |
2b01dfe3 | 8460 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 8461 | { |
ec7dc8ac | 8462 | struct task_group *tg, *parent; |
68318b8e | 8463 | |
2b01dfe3 | 8464 | if (!cgrp->parent) { |
68318b8e | 8465 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
8466 | return &init_task_group.css; |
8467 | } | |
8468 | ||
ec7dc8ac DG |
8469 | parent = cgroup_tg(cgrp->parent); |
8470 | tg = sched_create_group(parent); | |
68318b8e SV |
8471 | if (IS_ERR(tg)) |
8472 | return ERR_PTR(-ENOMEM); | |
8473 | ||
68318b8e SV |
8474 | return &tg->css; |
8475 | } | |
8476 | ||
41a2d6cf IM |
8477 | static void |
8478 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 8479 | { |
2b01dfe3 | 8480 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8481 | |
8482 | sched_destroy_group(tg); | |
8483 | } | |
8484 | ||
41a2d6cf | 8485 | static int |
be367d09 | 8486 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 8487 | { |
b68aa230 | 8488 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 8489 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
8490 | return -EINVAL; |
8491 | #else | |
68318b8e SV |
8492 | /* We don't support RT-tasks being in separate groups */ |
8493 | if (tsk->sched_class != &fair_sched_class) | |
8494 | return -EINVAL; | |
b68aa230 | 8495 | #endif |
be367d09 BB |
8496 | return 0; |
8497 | } | |
68318b8e | 8498 | |
be367d09 BB |
8499 | static int |
8500 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
8501 | struct task_struct *tsk, bool threadgroup) | |
8502 | { | |
8503 | int retval = cpu_cgroup_can_attach_task(cgrp, tsk); | |
8504 | if (retval) | |
8505 | return retval; | |
8506 | if (threadgroup) { | |
8507 | struct task_struct *c; | |
8508 | rcu_read_lock(); | |
8509 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8510 | retval = cpu_cgroup_can_attach_task(cgrp, c); | |
8511 | if (retval) { | |
8512 | rcu_read_unlock(); | |
8513 | return retval; | |
8514 | } | |
8515 | } | |
8516 | rcu_read_unlock(); | |
8517 | } | |
68318b8e SV |
8518 | return 0; |
8519 | } | |
8520 | ||
8521 | static void | |
2b01dfe3 | 8522 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
be367d09 BB |
8523 | struct cgroup *old_cont, struct task_struct *tsk, |
8524 | bool threadgroup) | |
68318b8e SV |
8525 | { |
8526 | sched_move_task(tsk); | |
be367d09 BB |
8527 | if (threadgroup) { |
8528 | struct task_struct *c; | |
8529 | rcu_read_lock(); | |
8530 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8531 | sched_move_task(c); | |
8532 | } | |
8533 | rcu_read_unlock(); | |
8534 | } | |
68318b8e SV |
8535 | } |
8536 | ||
052f1dc7 | 8537 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 8538 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 8539 | u64 shareval) |
68318b8e | 8540 | { |
2b01dfe3 | 8541 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
8542 | } |
8543 | ||
f4c753b7 | 8544 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 8545 | { |
2b01dfe3 | 8546 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8547 | |
8548 | return (u64) tg->shares; | |
8549 | } | |
6d6bc0ad | 8550 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8551 | |
052f1dc7 | 8552 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 8553 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 8554 | s64 val) |
6f505b16 | 8555 | { |
06ecb27c | 8556 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
8557 | } |
8558 | ||
06ecb27c | 8559 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 8560 | { |
06ecb27c | 8561 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 8562 | } |
d0b27fa7 PZ |
8563 | |
8564 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
8565 | u64 rt_period_us) | |
8566 | { | |
8567 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
8568 | } | |
8569 | ||
8570 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
8571 | { | |
8572 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
8573 | } | |
6d6bc0ad | 8574 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8575 | |
fe5c7cc2 | 8576 | static struct cftype cpu_files[] = { |
052f1dc7 | 8577 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8578 | { |
8579 | .name = "shares", | |
f4c753b7 PM |
8580 | .read_u64 = cpu_shares_read_u64, |
8581 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8582 | }, |
052f1dc7 PZ |
8583 | #endif |
8584 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 8585 | { |
9f0c1e56 | 8586 | .name = "rt_runtime_us", |
06ecb27c PM |
8587 | .read_s64 = cpu_rt_runtime_read, |
8588 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8589 | }, |
d0b27fa7 PZ |
8590 | { |
8591 | .name = "rt_period_us", | |
f4c753b7 PM |
8592 | .read_u64 = cpu_rt_period_read_uint, |
8593 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8594 | }, |
052f1dc7 | 8595 | #endif |
68318b8e SV |
8596 | }; |
8597 | ||
8598 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
8599 | { | |
fe5c7cc2 | 8600 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
8601 | } |
8602 | ||
8603 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
8604 | .name = "cpu", |
8605 | .create = cpu_cgroup_create, | |
8606 | .destroy = cpu_cgroup_destroy, | |
8607 | .can_attach = cpu_cgroup_can_attach, | |
8608 | .attach = cpu_cgroup_attach, | |
8609 | .populate = cpu_cgroup_populate, | |
8610 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
8611 | .early_init = 1, |
8612 | }; | |
8613 | ||
052f1dc7 | 8614 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
8615 | |
8616 | #ifdef CONFIG_CGROUP_CPUACCT | |
8617 | ||
8618 | /* | |
8619 | * CPU accounting code for task groups. | |
8620 | * | |
8621 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
8622 | * (balbir@in.ibm.com). | |
8623 | */ | |
8624 | ||
934352f2 | 8625 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
8626 | struct cpuacct { |
8627 | struct cgroup_subsys_state css; | |
8628 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 8629 | u64 __percpu *cpuusage; |
ef12fefa | 8630 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 8631 | struct cpuacct *parent; |
d842de87 SV |
8632 | }; |
8633 | ||
8634 | struct cgroup_subsys cpuacct_subsys; | |
8635 | ||
8636 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 8637 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 8638 | { |
32cd756a | 8639 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
8640 | struct cpuacct, css); |
8641 | } | |
8642 | ||
8643 | /* return cpu accounting group to which this task belongs */ | |
8644 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
8645 | { | |
8646 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
8647 | struct cpuacct, css); | |
8648 | } | |
8649 | ||
8650 | /* create a new cpu accounting group */ | |
8651 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 8652 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
8653 | { |
8654 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 8655 | int i; |
d842de87 SV |
8656 | |
8657 | if (!ca) | |
ef12fefa | 8658 | goto out; |
d842de87 SV |
8659 | |
8660 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
8661 | if (!ca->cpuusage) |
8662 | goto out_free_ca; | |
8663 | ||
8664 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
8665 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
8666 | goto out_free_counters; | |
d842de87 | 8667 | |
934352f2 BR |
8668 | if (cgrp->parent) |
8669 | ca->parent = cgroup_ca(cgrp->parent); | |
8670 | ||
d842de87 | 8671 | return &ca->css; |
ef12fefa BR |
8672 | |
8673 | out_free_counters: | |
8674 | while (--i >= 0) | |
8675 | percpu_counter_destroy(&ca->cpustat[i]); | |
8676 | free_percpu(ca->cpuusage); | |
8677 | out_free_ca: | |
8678 | kfree(ca); | |
8679 | out: | |
8680 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
8681 | } |
8682 | ||
8683 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 8684 | static void |
32cd756a | 8685 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8686 | { |
32cd756a | 8687 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 8688 | int i; |
d842de87 | 8689 | |
ef12fefa BR |
8690 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
8691 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
8692 | free_percpu(ca->cpuusage); |
8693 | kfree(ca); | |
8694 | } | |
8695 | ||
720f5498 KC |
8696 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
8697 | { | |
b36128c8 | 8698 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8699 | u64 data; |
8700 | ||
8701 | #ifndef CONFIG_64BIT | |
8702 | /* | |
8703 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
8704 | */ | |
05fa785c | 8705 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8706 | data = *cpuusage; |
05fa785c | 8707 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8708 | #else |
8709 | data = *cpuusage; | |
8710 | #endif | |
8711 | ||
8712 | return data; | |
8713 | } | |
8714 | ||
8715 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
8716 | { | |
b36128c8 | 8717 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8718 | |
8719 | #ifndef CONFIG_64BIT | |
8720 | /* | |
8721 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
8722 | */ | |
05fa785c | 8723 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8724 | *cpuusage = val; |
05fa785c | 8725 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8726 | #else |
8727 | *cpuusage = val; | |
8728 | #endif | |
8729 | } | |
8730 | ||
d842de87 | 8731 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 8732 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 8733 | { |
32cd756a | 8734 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
8735 | u64 totalcpuusage = 0; |
8736 | int i; | |
8737 | ||
720f5498 KC |
8738 | for_each_present_cpu(i) |
8739 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
8740 | |
8741 | return totalcpuusage; | |
8742 | } | |
8743 | ||
0297b803 DG |
8744 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
8745 | u64 reset) | |
8746 | { | |
8747 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8748 | int err = 0; | |
8749 | int i; | |
8750 | ||
8751 | if (reset) { | |
8752 | err = -EINVAL; | |
8753 | goto out; | |
8754 | } | |
8755 | ||
720f5498 KC |
8756 | for_each_present_cpu(i) |
8757 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 8758 | |
0297b803 DG |
8759 | out: |
8760 | return err; | |
8761 | } | |
8762 | ||
e9515c3c KC |
8763 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
8764 | struct seq_file *m) | |
8765 | { | |
8766 | struct cpuacct *ca = cgroup_ca(cgroup); | |
8767 | u64 percpu; | |
8768 | int i; | |
8769 | ||
8770 | for_each_present_cpu(i) { | |
8771 | percpu = cpuacct_cpuusage_read(ca, i); | |
8772 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
8773 | } | |
8774 | seq_printf(m, "\n"); | |
8775 | return 0; | |
8776 | } | |
8777 | ||
ef12fefa BR |
8778 | static const char *cpuacct_stat_desc[] = { |
8779 | [CPUACCT_STAT_USER] = "user", | |
8780 | [CPUACCT_STAT_SYSTEM] = "system", | |
8781 | }; | |
8782 | ||
8783 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
8784 | struct cgroup_map_cb *cb) | |
8785 | { | |
8786 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8787 | int i; | |
8788 | ||
8789 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
8790 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
8791 | val = cputime64_to_clock_t(val); | |
8792 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
8793 | } | |
8794 | return 0; | |
8795 | } | |
8796 | ||
d842de87 SV |
8797 | static struct cftype files[] = { |
8798 | { | |
8799 | .name = "usage", | |
f4c753b7 PM |
8800 | .read_u64 = cpuusage_read, |
8801 | .write_u64 = cpuusage_write, | |
d842de87 | 8802 | }, |
e9515c3c KC |
8803 | { |
8804 | .name = "usage_percpu", | |
8805 | .read_seq_string = cpuacct_percpu_seq_read, | |
8806 | }, | |
ef12fefa BR |
8807 | { |
8808 | .name = "stat", | |
8809 | .read_map = cpuacct_stats_show, | |
8810 | }, | |
d842de87 SV |
8811 | }; |
8812 | ||
32cd756a | 8813 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8814 | { |
32cd756a | 8815 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
8816 | } |
8817 | ||
8818 | /* | |
8819 | * charge this task's execution time to its accounting group. | |
8820 | * | |
8821 | * called with rq->lock held. | |
8822 | */ | |
8823 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
8824 | { | |
8825 | struct cpuacct *ca; | |
934352f2 | 8826 | int cpu; |
d842de87 | 8827 | |
c40c6f85 | 8828 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
8829 | return; |
8830 | ||
934352f2 | 8831 | cpu = task_cpu(tsk); |
a18b83b7 BR |
8832 | |
8833 | rcu_read_lock(); | |
8834 | ||
d842de87 | 8835 | ca = task_ca(tsk); |
d842de87 | 8836 | |
934352f2 | 8837 | for (; ca; ca = ca->parent) { |
b36128c8 | 8838 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
8839 | *cpuusage += cputime; |
8840 | } | |
a18b83b7 BR |
8841 | |
8842 | rcu_read_unlock(); | |
d842de87 SV |
8843 | } |
8844 | ||
fa535a77 AB |
8845 | /* |
8846 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
8847 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
8848 | * percpu_counter_add with values large enough to always overflow the | |
8849 | * per cpu batch limit causing bad SMP scalability. | |
8850 | * | |
8851 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
8852 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
8853 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
8854 | */ | |
8855 | #ifdef CONFIG_SMP | |
8856 | #define CPUACCT_BATCH \ | |
8857 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
8858 | #else | |
8859 | #define CPUACCT_BATCH 0 | |
8860 | #endif | |
8861 | ||
ef12fefa BR |
8862 | /* |
8863 | * Charge the system/user time to the task's accounting group. | |
8864 | */ | |
8865 | static void cpuacct_update_stats(struct task_struct *tsk, | |
8866 | enum cpuacct_stat_index idx, cputime_t val) | |
8867 | { | |
8868 | struct cpuacct *ca; | |
fa535a77 | 8869 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
8870 | |
8871 | if (unlikely(!cpuacct_subsys.active)) | |
8872 | return; | |
8873 | ||
8874 | rcu_read_lock(); | |
8875 | ca = task_ca(tsk); | |
8876 | ||
8877 | do { | |
fa535a77 | 8878 | __percpu_counter_add(&ca->cpustat[idx], val, batch); |
ef12fefa BR |
8879 | ca = ca->parent; |
8880 | } while (ca); | |
8881 | rcu_read_unlock(); | |
8882 | } | |
8883 | ||
d842de87 SV |
8884 | struct cgroup_subsys cpuacct_subsys = { |
8885 | .name = "cpuacct", | |
8886 | .create = cpuacct_create, | |
8887 | .destroy = cpuacct_destroy, | |
8888 | .populate = cpuacct_populate, | |
8889 | .subsys_id = cpuacct_subsys_id, | |
8890 | }; | |
8891 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
8892 | |
8893 | #ifndef CONFIG_SMP | |
8894 | ||
03b042bf PM |
8895 | void synchronize_sched_expedited(void) |
8896 | { | |
fc390cde | 8897 | barrier(); |
03b042bf PM |
8898 | } |
8899 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
8900 | ||
8901 | #else /* #ifndef CONFIG_SMP */ | |
8902 | ||
cc631fb7 | 8903 | static atomic_t synchronize_sched_expedited_count = ATOMIC_INIT(0); |
03b042bf | 8904 | |
cc631fb7 | 8905 | static int synchronize_sched_expedited_cpu_stop(void *data) |
03b042bf | 8906 | { |
969c7921 TH |
8907 | /* |
8908 | * There must be a full memory barrier on each affected CPU | |
8909 | * between the time that try_stop_cpus() is called and the | |
8910 | * time that it returns. | |
8911 | * | |
8912 | * In the current initial implementation of cpu_stop, the | |
8913 | * above condition is already met when the control reaches | |
8914 | * this point and the following smp_mb() is not strictly | |
8915 | * necessary. Do smp_mb() anyway for documentation and | |
8916 | * robustness against future implementation changes. | |
8917 | */ | |
cc631fb7 | 8918 | smp_mb(); /* See above comment block. */ |
969c7921 | 8919 | return 0; |
03b042bf | 8920 | } |
03b042bf PM |
8921 | |
8922 | /* | |
8923 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
8924 | * approach to force grace period to end quickly. This consumes | |
8925 | * significant time on all CPUs, and is thus not recommended for | |
8926 | * any sort of common-case code. | |
8927 | * | |
8928 | * Note that it is illegal to call this function while holding any | |
8929 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
8930 | * observe this restriction will result in deadlock. | |
8931 | */ | |
8932 | void synchronize_sched_expedited(void) | |
8933 | { | |
969c7921 | 8934 | int snap, trycount = 0; |
03b042bf PM |
8935 | |
8936 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
969c7921 | 8937 | snap = atomic_read(&synchronize_sched_expedited_count) + 1; |
03b042bf | 8938 | get_online_cpus(); |
969c7921 TH |
8939 | while (try_stop_cpus(cpu_online_mask, |
8940 | synchronize_sched_expedited_cpu_stop, | |
94458d5e | 8941 | NULL) == -EAGAIN) { |
03b042bf PM |
8942 | put_online_cpus(); |
8943 | if (trycount++ < 10) | |
8944 | udelay(trycount * num_online_cpus()); | |
8945 | else { | |
8946 | synchronize_sched(); | |
8947 | return; | |
8948 | } | |
969c7921 | 8949 | if (atomic_read(&synchronize_sched_expedited_count) - snap > 0) { |
03b042bf PM |
8950 | smp_mb(); /* ensure test happens before caller kfree */ |
8951 | return; | |
8952 | } | |
8953 | get_online_cpus(); | |
8954 | } | |
969c7921 | 8955 | atomic_inc(&synchronize_sched_expedited_count); |
cc631fb7 | 8956 | smp_mb__after_atomic_inc(); /* ensure post-GP actions seen after GP. */ |
03b042bf | 8957 | put_online_cpus(); |
03b042bf PM |
8958 | } |
8959 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
8960 | ||
8961 | #endif /* #else #ifndef CONFIG_SMP */ |