]>
Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
391e43da | 2 | * kernel/sched/core.c |
1da177e4 LT |
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 | 34 | #include <linux/highmem.h> |
1da177e4 LT |
35 | #include <asm/mmu_context.h> |
36 | #include <linux/interrupt.h> | |
c59ede7b | 37 | #include <linux/capability.h> |
1da177e4 LT |
38 | #include <linux/completion.h> |
39 | #include <linux/kernel_stat.h> | |
9a11b49a | 40 | #include <linux/debug_locks.h> |
cdd6c482 | 41 | #include <linux/perf_event.h> |
1da177e4 LT |
42 | #include <linux/security.h> |
43 | #include <linux/notifier.h> | |
44 | #include <linux/profile.h> | |
7dfb7103 | 45 | #include <linux/freezer.h> |
198e2f18 | 46 | #include <linux/vmalloc.h> |
1da177e4 LT |
47 | #include <linux/blkdev.h> |
48 | #include <linux/delay.h> | |
b488893a | 49 | #include <linux/pid_namespace.h> |
1da177e4 LT |
50 | #include <linux/smp.h> |
51 | #include <linux/threads.h> | |
52 | #include <linux/timer.h> | |
53 | #include <linux/rcupdate.h> | |
54 | #include <linux/cpu.h> | |
55 | #include <linux/cpuset.h> | |
56 | #include <linux/percpu.h> | |
b5aadf7f | 57 | #include <linux/proc_fs.h> |
1da177e4 | 58 | #include <linux/seq_file.h> |
e692ab53 | 59 | #include <linux/sysctl.h> |
1da177e4 LT |
60 | #include <linux/syscalls.h> |
61 | #include <linux/times.h> | |
8f0ab514 | 62 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 63 | #include <linux/kprobes.h> |
0ff92245 | 64 | #include <linux/delayacct.h> |
dff06c15 | 65 | #include <linux/unistd.h> |
f5ff8422 | 66 | #include <linux/pagemap.h> |
8f4d37ec | 67 | #include <linux/hrtimer.h> |
30914a58 | 68 | #include <linux/tick.h> |
f00b45c1 PZ |
69 | #include <linux/debugfs.h> |
70 | #include <linux/ctype.h> | |
6cd8a4bb | 71 | #include <linux/ftrace.h> |
5a0e3ad6 | 72 | #include <linux/slab.h> |
f1c6f1a7 | 73 | #include <linux/init_task.h> |
1da177e4 | 74 | |
5517d86b | 75 | #include <asm/tlb.h> |
838225b4 | 76 | #include <asm/irq_regs.h> |
e6e6685a GC |
77 | #ifdef CONFIG_PARAVIRT |
78 | #include <asm/paravirt.h> | |
79 | #endif | |
1da177e4 | 80 | |
029632fb | 81 | #include "sched.h" |
391e43da | 82 | #include "../workqueue_sched.h" |
6e0534f2 | 83 | |
a8d154b0 | 84 | #define CREATE_TRACE_POINTS |
ad8d75ff | 85 | #include <trace/events/sched.h> |
a8d154b0 | 86 | |
029632fb | 87 | void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) |
d0b27fa7 | 88 | { |
58088ad0 PT |
89 | unsigned long delta; |
90 | ktime_t soft, hard, now; | |
d0b27fa7 | 91 | |
58088ad0 PT |
92 | for (;;) { |
93 | if (hrtimer_active(period_timer)) | |
94 | break; | |
95 | ||
96 | now = hrtimer_cb_get_time(period_timer); | |
97 | hrtimer_forward(period_timer, now, period); | |
d0b27fa7 | 98 | |
58088ad0 PT |
99 | soft = hrtimer_get_softexpires(period_timer); |
100 | hard = hrtimer_get_expires(period_timer); | |
101 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
102 | __hrtimer_start_range_ns(period_timer, soft, delta, | |
103 | HRTIMER_MODE_ABS_PINNED, 0); | |
104 | } | |
105 | } | |
106 | ||
029632fb PZ |
107 | DEFINE_MUTEX(sched_domains_mutex); |
108 | DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); | |
dc61b1d6 | 109 | |
fe44d621 | 110 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 111 | |
029632fb | 112 | void update_rq_clock(struct rq *rq) |
3e51f33f | 113 | { |
fe44d621 | 114 | s64 delta; |
305e6835 | 115 | |
61eadef6 | 116 | if (rq->skip_clock_update > 0) |
f26f9aff | 117 | return; |
aa483808 | 118 | |
fe44d621 PZ |
119 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
120 | rq->clock += delta; | |
121 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
122 | } |
123 | ||
bf5c91ba IM |
124 | /* |
125 | * Debugging: various feature bits | |
126 | */ | |
f00b45c1 | 127 | |
f00b45c1 PZ |
128 | #define SCHED_FEAT(name, enabled) \ |
129 | (1UL << __SCHED_FEAT_##name) * enabled | | |
130 | ||
bf5c91ba | 131 | const_debug unsigned int sysctl_sched_features = |
391e43da | 132 | #include "features.h" |
f00b45c1 PZ |
133 | 0; |
134 | ||
135 | #undef SCHED_FEAT | |
136 | ||
137 | #ifdef CONFIG_SCHED_DEBUG | |
138 | #define SCHED_FEAT(name, enabled) \ | |
139 | #name , | |
140 | ||
983ed7a6 | 141 | static __read_mostly char *sched_feat_names[] = { |
391e43da | 142 | #include "features.h" |
f00b45c1 PZ |
143 | NULL |
144 | }; | |
145 | ||
146 | #undef SCHED_FEAT | |
147 | ||
34f3a814 | 148 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 149 | { |
f00b45c1 PZ |
150 | int i; |
151 | ||
152 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
153 | if (!(sysctl_sched_features & (1UL << i))) |
154 | seq_puts(m, "NO_"); | |
155 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 156 | } |
34f3a814 | 157 | seq_puts(m, "\n"); |
f00b45c1 | 158 | |
34f3a814 | 159 | return 0; |
f00b45c1 PZ |
160 | } |
161 | ||
162 | static ssize_t | |
163 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
164 | size_t cnt, loff_t *ppos) | |
165 | { | |
166 | char buf[64]; | |
7740191c | 167 | char *cmp; |
f00b45c1 PZ |
168 | int neg = 0; |
169 | int i; | |
170 | ||
171 | if (cnt > 63) | |
172 | cnt = 63; | |
173 | ||
174 | if (copy_from_user(&buf, ubuf, cnt)) | |
175 | return -EFAULT; | |
176 | ||
177 | buf[cnt] = 0; | |
7740191c | 178 | cmp = strstrip(buf); |
f00b45c1 | 179 | |
524429c3 | 180 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
181 | neg = 1; |
182 | cmp += 3; | |
183 | } | |
184 | ||
185 | for (i = 0; sched_feat_names[i]; i++) { | |
7740191c | 186 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f00b45c1 PZ |
187 | if (neg) |
188 | sysctl_sched_features &= ~(1UL << i); | |
189 | else | |
190 | sysctl_sched_features |= (1UL << i); | |
191 | break; | |
192 | } | |
193 | } | |
194 | ||
195 | if (!sched_feat_names[i]) | |
196 | return -EINVAL; | |
197 | ||
42994724 | 198 | *ppos += cnt; |
f00b45c1 PZ |
199 | |
200 | return cnt; | |
201 | } | |
202 | ||
34f3a814 LZ |
203 | static int sched_feat_open(struct inode *inode, struct file *filp) |
204 | { | |
205 | return single_open(filp, sched_feat_show, NULL); | |
206 | } | |
207 | ||
828c0950 | 208 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
209 | .open = sched_feat_open, |
210 | .write = sched_feat_write, | |
211 | .read = seq_read, | |
212 | .llseek = seq_lseek, | |
213 | .release = single_release, | |
f00b45c1 PZ |
214 | }; |
215 | ||
216 | static __init int sched_init_debug(void) | |
217 | { | |
f00b45c1 PZ |
218 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
219 | &sched_feat_fops); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | late_initcall(sched_init_debug); | |
224 | ||
225 | #endif | |
226 | ||
b82d9fdd PZ |
227 | /* |
228 | * Number of tasks to iterate in a single balance run. | |
229 | * Limited because this is done with IRQs disabled. | |
230 | */ | |
231 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
232 | ||
e9e9250b PZ |
233 | /* |
234 | * period over which we average the RT time consumption, measured | |
235 | * in ms. | |
236 | * | |
237 | * default: 1s | |
238 | */ | |
239 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
240 | ||
029632fb PZ |
241 | /* |
242 | * period over which we measure -rt task cpu usage in us. | |
243 | * default: 1s | |
244 | */ | |
245 | unsigned int sysctl_sched_rt_period = 1000000; | |
8a25d5de | 246 | |
029632fb PZ |
247 | __read_mostly int scheduler_running; |
248 | ||
249 | /* | |
250 | * part of the period that we allow rt tasks to run in us. | |
251 | * default: 0.95s | |
252 | */ | |
253 | int sysctl_sched_rt_runtime = 950000; | |
4866cde0 | 254 | |
4866cde0 | 255 | |
1da177e4 | 256 | |
0970d299 | 257 | /* |
0122ec5b | 258 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 259 | */ |
70b97a7f | 260 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
261 | __acquires(rq->lock) |
262 | { | |
0970d299 PZ |
263 | struct rq *rq; |
264 | ||
0122ec5b PZ |
265 | lockdep_assert_held(&p->pi_lock); |
266 | ||
3a5c359a | 267 | for (;;) { |
0970d299 | 268 | rq = task_rq(p); |
05fa785c | 269 | raw_spin_lock(&rq->lock); |
65cc8e48 | 270 | if (likely(rq == task_rq(p))) |
3a5c359a | 271 | return rq; |
05fa785c | 272 | raw_spin_unlock(&rq->lock); |
b29739f9 | 273 | } |
b29739f9 IM |
274 | } |
275 | ||
1da177e4 | 276 | /* |
0122ec5b | 277 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 278 | */ |
70b97a7f | 279 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 280 | __acquires(p->pi_lock) |
1da177e4 LT |
281 | __acquires(rq->lock) |
282 | { | |
70b97a7f | 283 | struct rq *rq; |
1da177e4 | 284 | |
3a5c359a | 285 | for (;;) { |
0122ec5b | 286 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 287 | rq = task_rq(p); |
05fa785c | 288 | raw_spin_lock(&rq->lock); |
65cc8e48 | 289 | if (likely(rq == task_rq(p))) |
3a5c359a | 290 | return rq; |
0122ec5b PZ |
291 | raw_spin_unlock(&rq->lock); |
292 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 293 | } |
1da177e4 LT |
294 | } |
295 | ||
a9957449 | 296 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
297 | __releases(rq->lock) |
298 | { | |
05fa785c | 299 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
300 | } |
301 | ||
0122ec5b PZ |
302 | static inline void |
303 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 304 | __releases(rq->lock) |
0122ec5b | 305 | __releases(p->pi_lock) |
1da177e4 | 306 | { |
0122ec5b PZ |
307 | raw_spin_unlock(&rq->lock); |
308 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
309 | } |
310 | ||
1da177e4 | 311 | /* |
cc2a73b5 | 312 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 313 | */ |
a9957449 | 314 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
315 | __acquires(rq->lock) |
316 | { | |
70b97a7f | 317 | struct rq *rq; |
1da177e4 LT |
318 | |
319 | local_irq_disable(); | |
320 | rq = this_rq(); | |
05fa785c | 321 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
322 | |
323 | return rq; | |
324 | } | |
325 | ||
8f4d37ec PZ |
326 | #ifdef CONFIG_SCHED_HRTICK |
327 | /* | |
328 | * Use HR-timers to deliver accurate preemption points. | |
329 | * | |
330 | * Its all a bit involved since we cannot program an hrt while holding the | |
331 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
332 | * reschedule event. | |
333 | * | |
334 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
335 | * rq->lock. | |
336 | */ | |
8f4d37ec | 337 | |
8f4d37ec PZ |
338 | static void hrtick_clear(struct rq *rq) |
339 | { | |
340 | if (hrtimer_active(&rq->hrtick_timer)) | |
341 | hrtimer_cancel(&rq->hrtick_timer); | |
342 | } | |
343 | ||
8f4d37ec PZ |
344 | /* |
345 | * High-resolution timer tick. | |
346 | * Runs from hardirq context with interrupts disabled. | |
347 | */ | |
348 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
349 | { | |
350 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
351 | ||
352 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
353 | ||
05fa785c | 354 | raw_spin_lock(&rq->lock); |
3e51f33f | 355 | update_rq_clock(rq); |
8f4d37ec | 356 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 357 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
358 | |
359 | return HRTIMER_NORESTART; | |
360 | } | |
361 | ||
95e904c7 | 362 | #ifdef CONFIG_SMP |
31656519 PZ |
363 | /* |
364 | * called from hardirq (IPI) context | |
365 | */ | |
366 | static void __hrtick_start(void *arg) | |
b328ca18 | 367 | { |
31656519 | 368 | struct rq *rq = arg; |
b328ca18 | 369 | |
05fa785c | 370 | raw_spin_lock(&rq->lock); |
31656519 PZ |
371 | hrtimer_restart(&rq->hrtick_timer); |
372 | rq->hrtick_csd_pending = 0; | |
05fa785c | 373 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
374 | } |
375 | ||
31656519 PZ |
376 | /* |
377 | * Called to set the hrtick timer state. | |
378 | * | |
379 | * called with rq->lock held and irqs disabled | |
380 | */ | |
029632fb | 381 | void hrtick_start(struct rq *rq, u64 delay) |
b328ca18 | 382 | { |
31656519 PZ |
383 | struct hrtimer *timer = &rq->hrtick_timer; |
384 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 385 | |
cc584b21 | 386 | hrtimer_set_expires(timer, time); |
31656519 PZ |
387 | |
388 | if (rq == this_rq()) { | |
389 | hrtimer_restart(timer); | |
390 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 391 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
392 | rq->hrtick_csd_pending = 1; |
393 | } | |
b328ca18 PZ |
394 | } |
395 | ||
396 | static int | |
397 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
398 | { | |
399 | int cpu = (int)(long)hcpu; | |
400 | ||
401 | switch (action) { | |
402 | case CPU_UP_CANCELED: | |
403 | case CPU_UP_CANCELED_FROZEN: | |
404 | case CPU_DOWN_PREPARE: | |
405 | case CPU_DOWN_PREPARE_FROZEN: | |
406 | case CPU_DEAD: | |
407 | case CPU_DEAD_FROZEN: | |
31656519 | 408 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
409 | return NOTIFY_OK; |
410 | } | |
411 | ||
412 | return NOTIFY_DONE; | |
413 | } | |
414 | ||
fa748203 | 415 | static __init void init_hrtick(void) |
b328ca18 PZ |
416 | { |
417 | hotcpu_notifier(hotplug_hrtick, 0); | |
418 | } | |
31656519 PZ |
419 | #else |
420 | /* | |
421 | * Called to set the hrtick timer state. | |
422 | * | |
423 | * called with rq->lock held and irqs disabled | |
424 | */ | |
029632fb | 425 | void hrtick_start(struct rq *rq, u64 delay) |
31656519 | 426 | { |
7f1e2ca9 | 427 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 428 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 429 | } |
b328ca18 | 430 | |
006c75f1 | 431 | static inline void init_hrtick(void) |
8f4d37ec | 432 | { |
8f4d37ec | 433 | } |
31656519 | 434 | #endif /* CONFIG_SMP */ |
8f4d37ec | 435 | |
31656519 | 436 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 437 | { |
31656519 PZ |
438 | #ifdef CONFIG_SMP |
439 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 440 | |
31656519 PZ |
441 | rq->hrtick_csd.flags = 0; |
442 | rq->hrtick_csd.func = __hrtick_start; | |
443 | rq->hrtick_csd.info = rq; | |
444 | #endif | |
8f4d37ec | 445 | |
31656519 PZ |
446 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
447 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 448 | } |
006c75f1 | 449 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
450 | static inline void hrtick_clear(struct rq *rq) |
451 | { | |
452 | } | |
453 | ||
8f4d37ec PZ |
454 | static inline void init_rq_hrtick(struct rq *rq) |
455 | { | |
456 | } | |
457 | ||
b328ca18 PZ |
458 | static inline void init_hrtick(void) |
459 | { | |
460 | } | |
006c75f1 | 461 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 462 | |
c24d20db IM |
463 | /* |
464 | * resched_task - mark a task 'to be rescheduled now'. | |
465 | * | |
466 | * On UP this means the setting of the need_resched flag, on SMP it | |
467 | * might also involve a cross-CPU call to trigger the scheduler on | |
468 | * the target CPU. | |
469 | */ | |
470 | #ifdef CONFIG_SMP | |
471 | ||
472 | #ifndef tsk_is_polling | |
473 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
474 | #endif | |
475 | ||
029632fb | 476 | void resched_task(struct task_struct *p) |
c24d20db IM |
477 | { |
478 | int cpu; | |
479 | ||
05fa785c | 480 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 481 | |
5ed0cec0 | 482 | if (test_tsk_need_resched(p)) |
c24d20db IM |
483 | return; |
484 | ||
5ed0cec0 | 485 | set_tsk_need_resched(p); |
c24d20db IM |
486 | |
487 | cpu = task_cpu(p); | |
488 | if (cpu == smp_processor_id()) | |
489 | return; | |
490 | ||
491 | /* NEED_RESCHED must be visible before we test polling */ | |
492 | smp_mb(); | |
493 | if (!tsk_is_polling(p)) | |
494 | smp_send_reschedule(cpu); | |
495 | } | |
496 | ||
029632fb | 497 | void resched_cpu(int cpu) |
c24d20db IM |
498 | { |
499 | struct rq *rq = cpu_rq(cpu); | |
500 | unsigned long flags; | |
501 | ||
05fa785c | 502 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
503 | return; |
504 | resched_task(cpu_curr(cpu)); | |
05fa785c | 505 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 506 | } |
06d8308c TG |
507 | |
508 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
509 | /* |
510 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
511 | * from an idle cpu. This is good for power-savings. | |
512 | * | |
513 | * We don't do similar optimization for completely idle system, as | |
514 | * selecting an idle cpu will add more delays to the timers than intended | |
515 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
516 | */ | |
517 | int get_nohz_timer_target(void) | |
518 | { | |
519 | int cpu = smp_processor_id(); | |
520 | int i; | |
521 | struct sched_domain *sd; | |
522 | ||
057f3fad | 523 | rcu_read_lock(); |
83cd4fe2 | 524 | for_each_domain(cpu, sd) { |
057f3fad PZ |
525 | for_each_cpu(i, sched_domain_span(sd)) { |
526 | if (!idle_cpu(i)) { | |
527 | cpu = i; | |
528 | goto unlock; | |
529 | } | |
530 | } | |
83cd4fe2 | 531 | } |
057f3fad PZ |
532 | unlock: |
533 | rcu_read_unlock(); | |
83cd4fe2 VP |
534 | return cpu; |
535 | } | |
06d8308c TG |
536 | /* |
537 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
538 | * idle CPU then this timer might expire before the next timer event | |
539 | * which is scheduled to wake up that CPU. In case of a completely | |
540 | * idle system the next event might even be infinite time into the | |
541 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
542 | * leaves the inner idle loop so the newly added timer is taken into | |
543 | * account when the CPU goes back to idle and evaluates the timer | |
544 | * wheel for the next timer event. | |
545 | */ | |
546 | void wake_up_idle_cpu(int cpu) | |
547 | { | |
548 | struct rq *rq = cpu_rq(cpu); | |
549 | ||
550 | if (cpu == smp_processor_id()) | |
551 | return; | |
552 | ||
553 | /* | |
554 | * This is safe, as this function is called with the timer | |
555 | * wheel base lock of (cpu) held. When the CPU is on the way | |
556 | * to idle and has not yet set rq->curr to idle then it will | |
557 | * be serialized on the timer wheel base lock and take the new | |
558 | * timer into account automatically. | |
559 | */ | |
560 | if (rq->curr != rq->idle) | |
561 | return; | |
562 | ||
563 | /* | |
564 | * We can set TIF_RESCHED on the idle task of the other CPU | |
565 | * lockless. The worst case is that the other CPU runs the | |
566 | * idle task through an additional NOOP schedule() | |
567 | */ | |
5ed0cec0 | 568 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
569 | |
570 | /* NEED_RESCHED must be visible before we test polling */ | |
571 | smp_mb(); | |
572 | if (!tsk_is_polling(rq->idle)) | |
573 | smp_send_reschedule(cpu); | |
574 | } | |
39c0cbe2 | 575 | |
ca38062e SS |
576 | static inline bool got_nohz_idle_kick(void) |
577 | { | |
1c792db7 SS |
578 | int cpu = smp_processor_id(); |
579 | return idle_cpu(cpu) && test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)); | |
ca38062e SS |
580 | } |
581 | ||
582 | #else /* CONFIG_NO_HZ */ | |
583 | ||
584 | static inline bool got_nohz_idle_kick(void) | |
585 | { | |
586 | return false; | |
587 | } | |
588 | ||
6d6bc0ad | 589 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 590 | |
029632fb | 591 | void sched_avg_update(struct rq *rq) |
e9e9250b PZ |
592 | { |
593 | s64 period = sched_avg_period(); | |
594 | ||
595 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
0d98bb26 WD |
596 | /* |
597 | * Inline assembly required to prevent the compiler | |
598 | * optimising this loop into a divmod call. | |
599 | * See __iter_div_u64_rem() for another example of this. | |
600 | */ | |
601 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
602 | rq->age_stamp += period; |
603 | rq->rt_avg /= 2; | |
604 | } | |
605 | } | |
606 | ||
6d6bc0ad | 607 | #else /* !CONFIG_SMP */ |
029632fb | 608 | void resched_task(struct task_struct *p) |
c24d20db | 609 | { |
05fa785c | 610 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 611 | set_tsk_need_resched(p); |
c24d20db | 612 | } |
6d6bc0ad | 613 | #endif /* CONFIG_SMP */ |
c24d20db | 614 | |
a790de99 PT |
615 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
616 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
c09595f6 | 617 | /* |
8277434e PT |
618 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
619 | * node and @up when leaving it for the final time. | |
620 | * | |
621 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 622 | */ |
029632fb | 623 | int walk_tg_tree_from(struct task_group *from, |
8277434e | 624 | tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
625 | { |
626 | struct task_group *parent, *child; | |
eb755805 | 627 | int ret; |
c09595f6 | 628 | |
8277434e PT |
629 | parent = from; |
630 | ||
c09595f6 | 631 | down: |
eb755805 PZ |
632 | ret = (*down)(parent, data); |
633 | if (ret) | |
8277434e | 634 | goto out; |
c09595f6 PZ |
635 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
636 | parent = child; | |
637 | goto down; | |
638 | ||
639 | up: | |
029632fb PZ |
640 | continue; |
641 | } | |
642 | ret = (*up)(parent, data); | |
643 | if (ret || parent == from) | |
644 | goto out; | |
1e3c88bd | 645 | |
029632fb PZ |
646 | child = parent; |
647 | parent = parent->parent; | |
648 | if (parent) | |
649 | goto up; | |
650 | out: | |
651 | return ret; | |
9c217245 IM |
652 | } |
653 | ||
029632fb | 654 | int tg_nop(struct task_group *tg, void *data) |
9c217245 | 655 | { |
029632fb | 656 | return 0; |
9c217245 | 657 | } |
029632fb PZ |
658 | #endif |
659 | ||
660 | void update_cpu_load(struct rq *this_rq); | |
9c217245 | 661 | |
45bf76df IM |
662 | static void set_load_weight(struct task_struct *p) |
663 | { | |
f05998d4 NR |
664 | int prio = p->static_prio - MAX_RT_PRIO; |
665 | struct load_weight *load = &p->se.load; | |
666 | ||
dd41f596 IM |
667 | /* |
668 | * SCHED_IDLE tasks get minimal weight: | |
669 | */ | |
670 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 671 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 672 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
673 | return; |
674 | } | |
71f8bd46 | 675 | |
c8b28116 | 676 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 677 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
678 | } |
679 | ||
371fd7e7 | 680 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 681 | { |
a64692a3 | 682 | update_rq_clock(rq); |
dd41f596 | 683 | sched_info_queued(p); |
371fd7e7 | 684 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
685 | } |
686 | ||
371fd7e7 | 687 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 688 | { |
a64692a3 | 689 | update_rq_clock(rq); |
46ac22ba | 690 | sched_info_dequeued(p); |
371fd7e7 | 691 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
692 | } |
693 | ||
1e3c88bd PZ |
694 | /* |
695 | * activate_task - move a task to the runqueue. | |
696 | */ | |
029632fb | 697 | void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
698 | { |
699 | if (task_contributes_to_load(p)) | |
700 | rq->nr_uninterruptible--; | |
701 | ||
371fd7e7 | 702 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
703 | } |
704 | ||
705 | /* | |
706 | * deactivate_task - remove a task from the runqueue. | |
707 | */ | |
029632fb | 708 | void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
709 | { |
710 | if (task_contributes_to_load(p)) | |
711 | rq->nr_uninterruptible++; | |
712 | ||
371fd7e7 | 713 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
714 | } |
715 | ||
b52bfee4 VP |
716 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
717 | ||
305e6835 VP |
718 | /* |
719 | * There are no locks covering percpu hardirq/softirq time. | |
720 | * They are only modified in account_system_vtime, on corresponding CPU | |
721 | * with interrupts disabled. So, writes are safe. | |
722 | * They are read and saved off onto struct rq in update_rq_clock(). | |
723 | * This may result in other CPU reading this CPU's irq time and can | |
724 | * race with irq/account_system_vtime on this CPU. We would either get old | |
8e92c201 PZ |
725 | * or new value with a side effect of accounting a slice of irq time to wrong |
726 | * task when irq is in progress while we read rq->clock. That is a worthy | |
727 | * compromise in place of having locks on each irq in account_system_time. | |
305e6835 | 728 | */ |
b52bfee4 VP |
729 | static DEFINE_PER_CPU(u64, cpu_hardirq_time); |
730 | static DEFINE_PER_CPU(u64, cpu_softirq_time); | |
731 | ||
732 | static DEFINE_PER_CPU(u64, irq_start_time); | |
733 | static int sched_clock_irqtime; | |
734 | ||
735 | void enable_sched_clock_irqtime(void) | |
736 | { | |
737 | sched_clock_irqtime = 1; | |
738 | } | |
739 | ||
740 | void disable_sched_clock_irqtime(void) | |
741 | { | |
742 | sched_clock_irqtime = 0; | |
743 | } | |
744 | ||
8e92c201 PZ |
745 | #ifndef CONFIG_64BIT |
746 | static DEFINE_PER_CPU(seqcount_t, irq_time_seq); | |
747 | ||
748 | static inline void irq_time_write_begin(void) | |
749 | { | |
750 | __this_cpu_inc(irq_time_seq.sequence); | |
751 | smp_wmb(); | |
752 | } | |
753 | ||
754 | static inline void irq_time_write_end(void) | |
755 | { | |
756 | smp_wmb(); | |
757 | __this_cpu_inc(irq_time_seq.sequence); | |
758 | } | |
759 | ||
760 | static inline u64 irq_time_read(int cpu) | |
761 | { | |
762 | u64 irq_time; | |
763 | unsigned seq; | |
764 | ||
765 | do { | |
766 | seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); | |
767 | irq_time = per_cpu(cpu_softirq_time, cpu) + | |
768 | per_cpu(cpu_hardirq_time, cpu); | |
769 | } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); | |
770 | ||
771 | return irq_time; | |
772 | } | |
773 | #else /* CONFIG_64BIT */ | |
774 | static inline void irq_time_write_begin(void) | |
775 | { | |
776 | } | |
777 | ||
778 | static inline void irq_time_write_end(void) | |
779 | { | |
780 | } | |
781 | ||
782 | static inline u64 irq_time_read(int cpu) | |
305e6835 | 783 | { |
305e6835 VP |
784 | return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); |
785 | } | |
8e92c201 | 786 | #endif /* CONFIG_64BIT */ |
305e6835 | 787 | |
fe44d621 PZ |
788 | /* |
789 | * Called before incrementing preempt_count on {soft,}irq_enter | |
790 | * and before decrementing preempt_count on {soft,}irq_exit. | |
791 | */ | |
b52bfee4 VP |
792 | void account_system_vtime(struct task_struct *curr) |
793 | { | |
794 | unsigned long flags; | |
fe44d621 | 795 | s64 delta; |
b52bfee4 | 796 | int cpu; |
b52bfee4 VP |
797 | |
798 | if (!sched_clock_irqtime) | |
799 | return; | |
800 | ||
801 | local_irq_save(flags); | |
802 | ||
b52bfee4 | 803 | cpu = smp_processor_id(); |
fe44d621 PZ |
804 | delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time); |
805 | __this_cpu_add(irq_start_time, delta); | |
806 | ||
8e92c201 | 807 | irq_time_write_begin(); |
b52bfee4 VP |
808 | /* |
809 | * We do not account for softirq time from ksoftirqd here. | |
810 | * We want to continue accounting softirq time to ksoftirqd thread | |
811 | * in that case, so as not to confuse scheduler with a special task | |
812 | * that do not consume any time, but still wants to run. | |
813 | */ | |
814 | if (hardirq_count()) | |
fe44d621 | 815 | __this_cpu_add(cpu_hardirq_time, delta); |
4dd53d89 | 816 | else if (in_serving_softirq() && curr != this_cpu_ksoftirqd()) |
fe44d621 | 817 | __this_cpu_add(cpu_softirq_time, delta); |
b52bfee4 | 818 | |
8e92c201 | 819 | irq_time_write_end(); |
b52bfee4 VP |
820 | local_irq_restore(flags); |
821 | } | |
b7dadc38 | 822 | EXPORT_SYMBOL_GPL(account_system_vtime); |
b52bfee4 | 823 | |
e6e6685a GC |
824 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
825 | ||
826 | #ifdef CONFIG_PARAVIRT | |
827 | static inline u64 steal_ticks(u64 steal) | |
aa483808 | 828 | { |
e6e6685a GC |
829 | if (unlikely(steal > NSEC_PER_SEC)) |
830 | return div_u64(steal, TICK_NSEC); | |
fe44d621 | 831 | |
e6e6685a GC |
832 | return __iter_div_u64_rem(steal, TICK_NSEC, &steal); |
833 | } | |
834 | #endif | |
835 | ||
fe44d621 | 836 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 837 | { |
095c0aa8 GC |
838 | /* |
839 | * In theory, the compile should just see 0 here, and optimize out the call | |
840 | * to sched_rt_avg_update. But I don't trust it... | |
841 | */ | |
842 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
843 | s64 steal = 0, irq_delta = 0; | |
844 | #endif | |
845 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 846 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
847 | |
848 | /* | |
849 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
850 | * this case when a previous update_rq_clock() happened inside a | |
851 | * {soft,}irq region. | |
852 | * | |
853 | * When this happens, we stop ->clock_task and only update the | |
854 | * prev_irq_time stamp to account for the part that fit, so that a next | |
855 | * update will consume the rest. This ensures ->clock_task is | |
856 | * monotonic. | |
857 | * | |
858 | * It does however cause some slight miss-attribution of {soft,}irq | |
859 | * time, a more accurate solution would be to update the irq_time using | |
860 | * the current rq->clock timestamp, except that would require using | |
861 | * atomic ops. | |
862 | */ | |
863 | if (irq_delta > delta) | |
864 | irq_delta = delta; | |
865 | ||
866 | rq->prev_irq_time += irq_delta; | |
867 | delta -= irq_delta; | |
095c0aa8 GC |
868 | #endif |
869 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
870 | if (static_branch((¶virt_steal_rq_enabled))) { | |
871 | u64 st; | |
872 | ||
873 | steal = paravirt_steal_clock(cpu_of(rq)); | |
874 | steal -= rq->prev_steal_time_rq; | |
875 | ||
876 | if (unlikely(steal > delta)) | |
877 | steal = delta; | |
878 | ||
879 | st = steal_ticks(steal); | |
880 | steal = st * TICK_NSEC; | |
881 | ||
882 | rq->prev_steal_time_rq += steal; | |
883 | ||
884 | delta -= steal; | |
885 | } | |
886 | #endif | |
887 | ||
fe44d621 PZ |
888 | rq->clock_task += delta; |
889 | ||
095c0aa8 GC |
890 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
891 | if ((irq_delta + steal) && sched_feat(NONTASK_POWER)) | |
892 | sched_rt_avg_update(rq, irq_delta + steal); | |
893 | #endif | |
aa483808 VP |
894 | } |
895 | ||
095c0aa8 | 896 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
abb74cef VP |
897 | static int irqtime_account_hi_update(void) |
898 | { | |
3292beb3 | 899 | u64 *cpustat = kcpustat_this_cpu->cpustat; |
abb74cef VP |
900 | unsigned long flags; |
901 | u64 latest_ns; | |
902 | int ret = 0; | |
903 | ||
904 | local_irq_save(flags); | |
905 | latest_ns = this_cpu_read(cpu_hardirq_time); | |
3292beb3 | 906 | if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat[CPUTIME_IRQ])) |
abb74cef VP |
907 | ret = 1; |
908 | local_irq_restore(flags); | |
909 | return ret; | |
910 | } | |
911 | ||
912 | static int irqtime_account_si_update(void) | |
913 | { | |
3292beb3 | 914 | u64 *cpustat = kcpustat_this_cpu->cpustat; |
abb74cef VP |
915 | unsigned long flags; |
916 | u64 latest_ns; | |
917 | int ret = 0; | |
918 | ||
919 | local_irq_save(flags); | |
920 | latest_ns = this_cpu_read(cpu_softirq_time); | |
3292beb3 | 921 | if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat[CPUTIME_SOFTIRQ])) |
abb74cef VP |
922 | ret = 1; |
923 | local_irq_restore(flags); | |
924 | return ret; | |
925 | } | |
926 | ||
fe44d621 | 927 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
305e6835 | 928 | |
abb74cef VP |
929 | #define sched_clock_irqtime (0) |
930 | ||
095c0aa8 | 931 | #endif |
b52bfee4 | 932 | |
34f971f6 PZ |
933 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
934 | { | |
935 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
936 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
937 | ||
938 | if (stop) { | |
939 | /* | |
940 | * Make it appear like a SCHED_FIFO task, its something | |
941 | * userspace knows about and won't get confused about. | |
942 | * | |
943 | * Also, it will make PI more or less work without too | |
944 | * much confusion -- but then, stop work should not | |
945 | * rely on PI working anyway. | |
946 | */ | |
947 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
948 | ||
949 | stop->sched_class = &stop_sched_class; | |
950 | } | |
951 | ||
952 | cpu_rq(cpu)->stop = stop; | |
953 | ||
954 | if (old_stop) { | |
955 | /* | |
956 | * Reset it back to a normal scheduling class so that | |
957 | * it can die in pieces. | |
958 | */ | |
959 | old_stop->sched_class = &rt_sched_class; | |
960 | } | |
961 | } | |
962 | ||
14531189 | 963 | /* |
dd41f596 | 964 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 965 | */ |
14531189 IM |
966 | static inline int __normal_prio(struct task_struct *p) |
967 | { | |
dd41f596 | 968 | return p->static_prio; |
14531189 IM |
969 | } |
970 | ||
b29739f9 IM |
971 | /* |
972 | * Calculate the expected normal priority: i.e. priority | |
973 | * without taking RT-inheritance into account. Might be | |
974 | * boosted by interactivity modifiers. Changes upon fork, | |
975 | * setprio syscalls, and whenever the interactivity | |
976 | * estimator recalculates. | |
977 | */ | |
36c8b586 | 978 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
979 | { |
980 | int prio; | |
981 | ||
e05606d3 | 982 | if (task_has_rt_policy(p)) |
b29739f9 IM |
983 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
984 | else | |
985 | prio = __normal_prio(p); | |
986 | return prio; | |
987 | } | |
988 | ||
989 | /* | |
990 | * Calculate the current priority, i.e. the priority | |
991 | * taken into account by the scheduler. This value might | |
992 | * be boosted by RT tasks, or might be boosted by | |
993 | * interactivity modifiers. Will be RT if the task got | |
994 | * RT-boosted. If not then it returns p->normal_prio. | |
995 | */ | |
36c8b586 | 996 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
997 | { |
998 | p->normal_prio = normal_prio(p); | |
999 | /* | |
1000 | * If we are RT tasks or we were boosted to RT priority, | |
1001 | * keep the priority unchanged. Otherwise, update priority | |
1002 | * to the normal priority: | |
1003 | */ | |
1004 | if (!rt_prio(p->prio)) | |
1005 | return p->normal_prio; | |
1006 | return p->prio; | |
1007 | } | |
1008 | ||
1da177e4 LT |
1009 | /** |
1010 | * task_curr - is this task currently executing on a CPU? | |
1011 | * @p: the task in question. | |
1012 | */ | |
36c8b586 | 1013 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1014 | { |
1015 | return cpu_curr(task_cpu(p)) == p; | |
1016 | } | |
1017 | ||
cb469845 SR |
1018 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1019 | const struct sched_class *prev_class, | |
da7a735e | 1020 | int oldprio) |
cb469845 SR |
1021 | { |
1022 | if (prev_class != p->sched_class) { | |
1023 | if (prev_class->switched_from) | |
da7a735e PZ |
1024 | prev_class->switched_from(rq, p); |
1025 | p->sched_class->switched_to(rq, p); | |
1026 | } else if (oldprio != p->prio) | |
1027 | p->sched_class->prio_changed(rq, p, oldprio); | |
cb469845 SR |
1028 | } |
1029 | ||
029632fb | 1030 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
1e5a7405 PZ |
1031 | { |
1032 | const struct sched_class *class; | |
1033 | ||
1034 | if (p->sched_class == rq->curr->sched_class) { | |
1035 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
1036 | } else { | |
1037 | for_each_class(class) { | |
1038 | if (class == rq->curr->sched_class) | |
1039 | break; | |
1040 | if (class == p->sched_class) { | |
1041 | resched_task(rq->curr); | |
1042 | break; | |
1043 | } | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | /* | |
1048 | * A queue event has occurred, and we're going to schedule. In | |
1049 | * this case, we can save a useless back to back clock update. | |
1050 | */ | |
fd2f4419 | 1051 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
1052 | rq->skip_clock_update = 1; |
1053 | } | |
1054 | ||
1da177e4 | 1055 | #ifdef CONFIG_SMP |
dd41f596 | 1056 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1057 | { |
e2912009 PZ |
1058 | #ifdef CONFIG_SCHED_DEBUG |
1059 | /* | |
1060 | * We should never call set_task_cpu() on a blocked task, | |
1061 | * ttwu() will sort out the placement. | |
1062 | */ | |
077614ee PZ |
1063 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
1064 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
0122ec5b PZ |
1065 | |
1066 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
1067 | /* |
1068 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
1069 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
1070 | * | |
1071 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
1072 | * see set_task_rq(). | |
1073 | * | |
1074 | * Furthermore, all task_rq users should acquire both locks, see | |
1075 | * task_rq_lock(). | |
1076 | */ | |
0122ec5b PZ |
1077 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
1078 | lockdep_is_held(&task_rq(p)->lock))); | |
1079 | #endif | |
e2912009 PZ |
1080 | #endif |
1081 | ||
de1d7286 | 1082 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 1083 | |
0c69774e PZ |
1084 | if (task_cpu(p) != new_cpu) { |
1085 | p->se.nr_migrations++; | |
a8b0ca17 | 1086 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 1087 | } |
dd41f596 IM |
1088 | |
1089 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1090 | } |
1091 | ||
969c7921 | 1092 | struct migration_arg { |
36c8b586 | 1093 | struct task_struct *task; |
1da177e4 | 1094 | int dest_cpu; |
70b97a7f | 1095 | }; |
1da177e4 | 1096 | |
969c7921 TH |
1097 | static int migration_cpu_stop(void *data); |
1098 | ||
1da177e4 LT |
1099 | /* |
1100 | * wait_task_inactive - wait for a thread to unschedule. | |
1101 | * | |
85ba2d86 RM |
1102 | * If @match_state is nonzero, it's the @p->state value just checked and |
1103 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1104 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1105 | * we return a positive number (its total switch count). If a second call | |
1106 | * a short while later returns the same number, the caller can be sure that | |
1107 | * @p has remained unscheduled the whole time. | |
1108 | * | |
1da177e4 LT |
1109 | * The caller must ensure that the task *will* unschedule sometime soon, |
1110 | * else this function might spin for a *long* time. This function can't | |
1111 | * be called with interrupts off, or it may introduce deadlock with | |
1112 | * smp_call_function() if an IPI is sent by the same process we are | |
1113 | * waiting to become inactive. | |
1114 | */ | |
85ba2d86 | 1115 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1116 | { |
1117 | unsigned long flags; | |
dd41f596 | 1118 | int running, on_rq; |
85ba2d86 | 1119 | unsigned long ncsw; |
70b97a7f | 1120 | struct rq *rq; |
1da177e4 | 1121 | |
3a5c359a AK |
1122 | for (;;) { |
1123 | /* | |
1124 | * We do the initial early heuristics without holding | |
1125 | * any task-queue locks at all. We'll only try to get | |
1126 | * the runqueue lock when things look like they will | |
1127 | * work out! | |
1128 | */ | |
1129 | rq = task_rq(p); | |
fa490cfd | 1130 | |
3a5c359a AK |
1131 | /* |
1132 | * If the task is actively running on another CPU | |
1133 | * still, just relax and busy-wait without holding | |
1134 | * any locks. | |
1135 | * | |
1136 | * NOTE! Since we don't hold any locks, it's not | |
1137 | * even sure that "rq" stays as the right runqueue! | |
1138 | * But we don't care, since "task_running()" will | |
1139 | * return false if the runqueue has changed and p | |
1140 | * is actually now running somewhere else! | |
1141 | */ | |
85ba2d86 RM |
1142 | while (task_running(rq, p)) { |
1143 | if (match_state && unlikely(p->state != match_state)) | |
1144 | return 0; | |
3a5c359a | 1145 | cpu_relax(); |
85ba2d86 | 1146 | } |
fa490cfd | 1147 | |
3a5c359a AK |
1148 | /* |
1149 | * Ok, time to look more closely! We need the rq | |
1150 | * lock now, to be *sure*. If we're wrong, we'll | |
1151 | * just go back and repeat. | |
1152 | */ | |
1153 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 1154 | trace_sched_wait_task(p); |
3a5c359a | 1155 | running = task_running(rq, p); |
fd2f4419 | 1156 | on_rq = p->on_rq; |
85ba2d86 | 1157 | ncsw = 0; |
f31e11d8 | 1158 | if (!match_state || p->state == match_state) |
93dcf55f | 1159 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 1160 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 1161 | |
85ba2d86 RM |
1162 | /* |
1163 | * If it changed from the expected state, bail out now. | |
1164 | */ | |
1165 | if (unlikely(!ncsw)) | |
1166 | break; | |
1167 | ||
3a5c359a AK |
1168 | /* |
1169 | * Was it really running after all now that we | |
1170 | * checked with the proper locks actually held? | |
1171 | * | |
1172 | * Oops. Go back and try again.. | |
1173 | */ | |
1174 | if (unlikely(running)) { | |
1175 | cpu_relax(); | |
1176 | continue; | |
1177 | } | |
fa490cfd | 1178 | |
3a5c359a AK |
1179 | /* |
1180 | * It's not enough that it's not actively running, | |
1181 | * it must be off the runqueue _entirely_, and not | |
1182 | * preempted! | |
1183 | * | |
80dd99b3 | 1184 | * So if it was still runnable (but just not actively |
3a5c359a AK |
1185 | * running right now), it's preempted, and we should |
1186 | * yield - it could be a while. | |
1187 | */ | |
1188 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
1189 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
1190 | ||
1191 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1192 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
1193 | continue; |
1194 | } | |
fa490cfd | 1195 | |
3a5c359a AK |
1196 | /* |
1197 | * Ahh, all good. It wasn't running, and it wasn't | |
1198 | * runnable, which means that it will never become | |
1199 | * running in the future either. We're all done! | |
1200 | */ | |
1201 | break; | |
1202 | } | |
85ba2d86 RM |
1203 | |
1204 | return ncsw; | |
1da177e4 LT |
1205 | } |
1206 | ||
1207 | /*** | |
1208 | * kick_process - kick a running thread to enter/exit the kernel | |
1209 | * @p: the to-be-kicked thread | |
1210 | * | |
1211 | * Cause a process which is running on another CPU to enter | |
1212 | * kernel-mode, without any delay. (to get signals handled.) | |
1213 | * | |
25985edc | 1214 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
1215 | * because all it wants to ensure is that the remote task enters |
1216 | * the kernel. If the IPI races and the task has been migrated | |
1217 | * to another CPU then no harm is done and the purpose has been | |
1218 | * achieved as well. | |
1219 | */ | |
36c8b586 | 1220 | void kick_process(struct task_struct *p) |
1da177e4 LT |
1221 | { |
1222 | int cpu; | |
1223 | ||
1224 | preempt_disable(); | |
1225 | cpu = task_cpu(p); | |
1226 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
1227 | smp_send_reschedule(cpu); | |
1228 | preempt_enable(); | |
1229 | } | |
b43e3521 | 1230 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 1231 | #endif /* CONFIG_SMP */ |
1da177e4 | 1232 | |
970b13ba | 1233 | #ifdef CONFIG_SMP |
30da688e | 1234 | /* |
013fdb80 | 1235 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 1236 | */ |
5da9a0fb PZ |
1237 | static int select_fallback_rq(int cpu, struct task_struct *p) |
1238 | { | |
1239 | int dest_cpu; | |
1240 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
1241 | ||
1242 | /* Look for allowed, online CPU in same node. */ | |
1243 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
fa17b507 | 1244 | if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
5da9a0fb PZ |
1245 | return dest_cpu; |
1246 | ||
1247 | /* Any allowed, online CPU? */ | |
fa17b507 | 1248 | dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask); |
5da9a0fb PZ |
1249 | if (dest_cpu < nr_cpu_ids) |
1250 | return dest_cpu; | |
1251 | ||
1252 | /* No more Mr. Nice Guy. */ | |
48c5ccae PZ |
1253 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
1254 | /* | |
1255 | * Don't tell them about moving exiting tasks or | |
1256 | * kernel threads (both mm NULL), since they never | |
1257 | * leave kernel. | |
1258 | */ | |
1259 | if (p->mm && printk_ratelimit()) { | |
1260 | printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n", | |
1261 | task_pid_nr(p), p->comm, cpu); | |
5da9a0fb PZ |
1262 | } |
1263 | ||
1264 | return dest_cpu; | |
1265 | } | |
1266 | ||
e2912009 | 1267 | /* |
013fdb80 | 1268 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 1269 | */ |
970b13ba | 1270 | static inline |
7608dec2 | 1271 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 1272 | { |
7608dec2 | 1273 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
e2912009 PZ |
1274 | |
1275 | /* | |
1276 | * In order not to call set_task_cpu() on a blocking task we need | |
1277 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
1278 | * cpu. | |
1279 | * | |
1280 | * Since this is common to all placement strategies, this lives here. | |
1281 | * | |
1282 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
1283 | * not worry about this generic constraint ] | |
1284 | */ | |
fa17b507 | 1285 | if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || |
70f11205 | 1286 | !cpu_online(cpu))) |
5da9a0fb | 1287 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
1288 | |
1289 | return cpu; | |
970b13ba | 1290 | } |
09a40af5 MG |
1291 | |
1292 | static void update_avg(u64 *avg, u64 sample) | |
1293 | { | |
1294 | s64 diff = sample - *avg; | |
1295 | *avg += diff >> 3; | |
1296 | } | |
970b13ba PZ |
1297 | #endif |
1298 | ||
d7c01d27 | 1299 | static void |
b84cb5df | 1300 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 1301 | { |
d7c01d27 | 1302 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
1303 | struct rq *rq = this_rq(); |
1304 | ||
d7c01d27 PZ |
1305 | #ifdef CONFIG_SMP |
1306 | int this_cpu = smp_processor_id(); | |
1307 | ||
1308 | if (cpu == this_cpu) { | |
1309 | schedstat_inc(rq, ttwu_local); | |
1310 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
1311 | } else { | |
1312 | struct sched_domain *sd; | |
1313 | ||
1314 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 1315 | rcu_read_lock(); |
d7c01d27 PZ |
1316 | for_each_domain(this_cpu, sd) { |
1317 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
1318 | schedstat_inc(sd, ttwu_wake_remote); | |
1319 | break; | |
1320 | } | |
1321 | } | |
057f3fad | 1322 | rcu_read_unlock(); |
d7c01d27 | 1323 | } |
f339b9dc PZ |
1324 | |
1325 | if (wake_flags & WF_MIGRATED) | |
1326 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
1327 | ||
d7c01d27 PZ |
1328 | #endif /* CONFIG_SMP */ |
1329 | ||
1330 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 1331 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
1332 | |
1333 | if (wake_flags & WF_SYNC) | |
9ed3811a | 1334 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 1335 | |
d7c01d27 PZ |
1336 | #endif /* CONFIG_SCHEDSTATS */ |
1337 | } | |
1338 | ||
1339 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
1340 | { | |
9ed3811a | 1341 | activate_task(rq, p, en_flags); |
fd2f4419 | 1342 | p->on_rq = 1; |
c2f7115e PZ |
1343 | |
1344 | /* if a worker is waking up, notify workqueue */ | |
1345 | if (p->flags & PF_WQ_WORKER) | |
1346 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
1347 | } |
1348 | ||
23f41eeb PZ |
1349 | /* |
1350 | * Mark the task runnable and perform wakeup-preemption. | |
1351 | */ | |
89363381 | 1352 | static void |
23f41eeb | 1353 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 1354 | { |
89363381 | 1355 | trace_sched_wakeup(p, true); |
9ed3811a TH |
1356 | check_preempt_curr(rq, p, wake_flags); |
1357 | ||
1358 | p->state = TASK_RUNNING; | |
1359 | #ifdef CONFIG_SMP | |
1360 | if (p->sched_class->task_woken) | |
1361 | p->sched_class->task_woken(rq, p); | |
1362 | ||
e69c6341 | 1363 | if (rq->idle_stamp) { |
9ed3811a TH |
1364 | u64 delta = rq->clock - rq->idle_stamp; |
1365 | u64 max = 2*sysctl_sched_migration_cost; | |
1366 | ||
1367 | if (delta > max) | |
1368 | rq->avg_idle = max; | |
1369 | else | |
1370 | update_avg(&rq->avg_idle, delta); | |
1371 | rq->idle_stamp = 0; | |
1372 | } | |
1373 | #endif | |
1374 | } | |
1375 | ||
c05fbafb PZ |
1376 | static void |
1377 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
1378 | { | |
1379 | #ifdef CONFIG_SMP | |
1380 | if (p->sched_contributes_to_load) | |
1381 | rq->nr_uninterruptible--; | |
1382 | #endif | |
1383 | ||
1384 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
1385 | ttwu_do_wakeup(rq, p, wake_flags); | |
1386 | } | |
1387 | ||
1388 | /* | |
1389 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
1390 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
1391 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
1392 | * the task is still ->on_rq. | |
1393 | */ | |
1394 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
1395 | { | |
1396 | struct rq *rq; | |
1397 | int ret = 0; | |
1398 | ||
1399 | rq = __task_rq_lock(p); | |
1400 | if (p->on_rq) { | |
1401 | ttwu_do_wakeup(rq, p, wake_flags); | |
1402 | ret = 1; | |
1403 | } | |
1404 | __task_rq_unlock(rq); | |
1405 | ||
1406 | return ret; | |
1407 | } | |
1408 | ||
317f3941 | 1409 | #ifdef CONFIG_SMP |
fa14ff4a | 1410 | static void sched_ttwu_pending(void) |
317f3941 PZ |
1411 | { |
1412 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
1413 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
1414 | struct task_struct *p; | |
317f3941 PZ |
1415 | |
1416 | raw_spin_lock(&rq->lock); | |
1417 | ||
fa14ff4a PZ |
1418 | while (llist) { |
1419 | p = llist_entry(llist, struct task_struct, wake_entry); | |
1420 | llist = llist_next(llist); | |
317f3941 PZ |
1421 | ttwu_do_activate(rq, p, 0); |
1422 | } | |
1423 | ||
1424 | raw_spin_unlock(&rq->lock); | |
1425 | } | |
1426 | ||
1427 | void scheduler_ipi(void) | |
1428 | { | |
ca38062e | 1429 | if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) |
c5d753a5 PZ |
1430 | return; |
1431 | ||
1432 | /* | |
1433 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
1434 | * traditionally all their work was done from the interrupt return | |
1435 | * path. Now that we actually do some work, we need to make sure | |
1436 | * we do call them. | |
1437 | * | |
1438 | * Some archs already do call them, luckily irq_enter/exit nest | |
1439 | * properly. | |
1440 | * | |
1441 | * Arguably we should visit all archs and update all handlers, | |
1442 | * however a fair share of IPIs are still resched only so this would | |
1443 | * somewhat pessimize the simple resched case. | |
1444 | */ | |
1445 | irq_enter(); | |
fa14ff4a | 1446 | sched_ttwu_pending(); |
ca38062e SS |
1447 | |
1448 | /* | |
1449 | * Check if someone kicked us for doing the nohz idle load balance. | |
1450 | */ | |
6eb57e0d SS |
1451 | if (unlikely(got_nohz_idle_kick() && !need_resched())) { |
1452 | this_rq()->idle_balance = 1; | |
ca38062e | 1453 | raise_softirq_irqoff(SCHED_SOFTIRQ); |
6eb57e0d | 1454 | } |
c5d753a5 | 1455 | irq_exit(); |
317f3941 PZ |
1456 | } |
1457 | ||
1458 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
1459 | { | |
fa14ff4a | 1460 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) |
317f3941 PZ |
1461 | smp_send_reschedule(cpu); |
1462 | } | |
d6aa8f85 PZ |
1463 | |
1464 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
1465 | static int ttwu_activate_remote(struct task_struct *p, int wake_flags) | |
1466 | { | |
1467 | struct rq *rq; | |
1468 | int ret = 0; | |
1469 | ||
1470 | rq = __task_rq_lock(p); | |
1471 | if (p->on_cpu) { | |
1472 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); | |
1473 | ttwu_do_wakeup(rq, p, wake_flags); | |
1474 | ret = 1; | |
1475 | } | |
1476 | __task_rq_unlock(rq); | |
1477 | ||
1478 | return ret; | |
1479 | ||
1480 | } | |
1481 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
1482 | #endif /* CONFIG_SMP */ | |
317f3941 | 1483 | |
c05fbafb PZ |
1484 | static void ttwu_queue(struct task_struct *p, int cpu) |
1485 | { | |
1486 | struct rq *rq = cpu_rq(cpu); | |
1487 | ||
17d9f311 | 1488 | #if defined(CONFIG_SMP) |
317f3941 | 1489 | if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) { |
f01114cb | 1490 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
1491 | ttwu_queue_remote(p, cpu); |
1492 | return; | |
1493 | } | |
1494 | #endif | |
1495 | ||
c05fbafb PZ |
1496 | raw_spin_lock(&rq->lock); |
1497 | ttwu_do_activate(rq, p, 0); | |
1498 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
1499 | } |
1500 | ||
1501 | /** | |
1da177e4 | 1502 | * try_to_wake_up - wake up a thread |
9ed3811a | 1503 | * @p: the thread to be awakened |
1da177e4 | 1504 | * @state: the mask of task states that can be woken |
9ed3811a | 1505 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
1506 | * |
1507 | * Put it on the run-queue if it's not already there. The "current" | |
1508 | * thread is always on the run-queue (except when the actual | |
1509 | * re-schedule is in progress), and as such you're allowed to do | |
1510 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
1511 | * runnable without the overhead of this. | |
1512 | * | |
9ed3811a TH |
1513 | * Returns %true if @p was woken up, %false if it was already running |
1514 | * or @state didn't match @p's state. | |
1da177e4 | 1515 | */ |
e4a52bcb PZ |
1516 | static int |
1517 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 1518 | { |
1da177e4 | 1519 | unsigned long flags; |
c05fbafb | 1520 | int cpu, success = 0; |
2398f2c6 | 1521 | |
04e2f174 | 1522 | smp_wmb(); |
013fdb80 | 1523 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 1524 | if (!(p->state & state)) |
1da177e4 LT |
1525 | goto out; |
1526 | ||
c05fbafb | 1527 | success = 1; /* we're going to change ->state */ |
1da177e4 | 1528 | cpu = task_cpu(p); |
1da177e4 | 1529 | |
c05fbafb PZ |
1530 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
1531 | goto stat; | |
1da177e4 | 1532 | |
1da177e4 | 1533 | #ifdef CONFIG_SMP |
e9c84311 | 1534 | /* |
c05fbafb PZ |
1535 | * If the owning (remote) cpu is still in the middle of schedule() with |
1536 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 1537 | */ |
e4a52bcb PZ |
1538 | while (p->on_cpu) { |
1539 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
1540 | /* | |
d6aa8f85 PZ |
1541 | * In case the architecture enables interrupts in |
1542 | * context_switch(), we cannot busy wait, since that | |
1543 | * would lead to deadlocks when an interrupt hits and | |
1544 | * tries to wake up @prev. So bail and do a complete | |
1545 | * remote wakeup. | |
e4a52bcb | 1546 | */ |
d6aa8f85 | 1547 | if (ttwu_activate_remote(p, wake_flags)) |
c05fbafb | 1548 | goto stat; |
d6aa8f85 | 1549 | #else |
e4a52bcb | 1550 | cpu_relax(); |
d6aa8f85 | 1551 | #endif |
371fd7e7 | 1552 | } |
0970d299 | 1553 | /* |
e4a52bcb | 1554 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 1555 | */ |
e4a52bcb | 1556 | smp_rmb(); |
1da177e4 | 1557 | |
a8e4f2ea | 1558 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 1559 | p->state = TASK_WAKING; |
e7693a36 | 1560 | |
e4a52bcb | 1561 | if (p->sched_class->task_waking) |
74f8e4b2 | 1562 | p->sched_class->task_waking(p); |
efbbd05a | 1563 | |
7608dec2 | 1564 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
1565 | if (task_cpu(p) != cpu) { |
1566 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 1567 | set_task_cpu(p, cpu); |
f339b9dc | 1568 | } |
1da177e4 | 1569 | #endif /* CONFIG_SMP */ |
1da177e4 | 1570 | |
c05fbafb PZ |
1571 | ttwu_queue(p, cpu); |
1572 | stat: | |
b84cb5df | 1573 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 1574 | out: |
013fdb80 | 1575 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
1576 | |
1577 | return success; | |
1578 | } | |
1579 | ||
21aa9af0 TH |
1580 | /** |
1581 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
1582 | * @p: the thread to be awakened | |
1583 | * | |
2acca55e | 1584 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 1585 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 1586 | * the current task. |
21aa9af0 TH |
1587 | */ |
1588 | static void try_to_wake_up_local(struct task_struct *p) | |
1589 | { | |
1590 | struct rq *rq = task_rq(p); | |
21aa9af0 TH |
1591 | |
1592 | BUG_ON(rq != this_rq()); | |
1593 | BUG_ON(p == current); | |
1594 | lockdep_assert_held(&rq->lock); | |
1595 | ||
2acca55e PZ |
1596 | if (!raw_spin_trylock(&p->pi_lock)) { |
1597 | raw_spin_unlock(&rq->lock); | |
1598 | raw_spin_lock(&p->pi_lock); | |
1599 | raw_spin_lock(&rq->lock); | |
1600 | } | |
1601 | ||
21aa9af0 | 1602 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 1603 | goto out; |
21aa9af0 | 1604 | |
fd2f4419 | 1605 | if (!p->on_rq) |
d7c01d27 PZ |
1606 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
1607 | ||
23f41eeb | 1608 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 1609 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
1610 | out: |
1611 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
1612 | } |
1613 | ||
50fa610a DH |
1614 | /** |
1615 | * wake_up_process - Wake up a specific process | |
1616 | * @p: The process to be woken up. | |
1617 | * | |
1618 | * Attempt to wake up the nominated process and move it to the set of runnable | |
1619 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
1620 | * running. | |
1621 | * | |
1622 | * It may be assumed that this function implies a write memory barrier before | |
1623 | * changing the task state if and only if any tasks are woken up. | |
1624 | */ | |
7ad5b3a5 | 1625 | int wake_up_process(struct task_struct *p) |
1da177e4 | 1626 | { |
d9514f6c | 1627 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 1628 | } |
1da177e4 LT |
1629 | EXPORT_SYMBOL(wake_up_process); |
1630 | ||
7ad5b3a5 | 1631 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
1632 | { |
1633 | return try_to_wake_up(p, state, 0); | |
1634 | } | |
1635 | ||
1da177e4 LT |
1636 | /* |
1637 | * Perform scheduler related setup for a newly forked process p. | |
1638 | * p is forked by current. | |
dd41f596 IM |
1639 | * |
1640 | * __sched_fork() is basic setup used by init_idle() too: | |
1641 | */ | |
1642 | static void __sched_fork(struct task_struct *p) | |
1643 | { | |
fd2f4419 PZ |
1644 | p->on_rq = 0; |
1645 | ||
1646 | p->se.on_rq = 0; | |
dd41f596 IM |
1647 | p->se.exec_start = 0; |
1648 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 1649 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 1650 | p->se.nr_migrations = 0; |
da7a735e | 1651 | p->se.vruntime = 0; |
fd2f4419 | 1652 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
1653 | |
1654 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 1655 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 1656 | #endif |
476d139c | 1657 | |
fa717060 | 1658 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 1659 | |
e107be36 AK |
1660 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1661 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
1662 | #endif | |
dd41f596 IM |
1663 | } |
1664 | ||
1665 | /* | |
1666 | * fork()/clone()-time setup: | |
1667 | */ | |
3e51e3ed | 1668 | void sched_fork(struct task_struct *p) |
dd41f596 | 1669 | { |
0122ec5b | 1670 | unsigned long flags; |
dd41f596 IM |
1671 | int cpu = get_cpu(); |
1672 | ||
1673 | __sched_fork(p); | |
06b83b5f | 1674 | /* |
0017d735 | 1675 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
1676 | * nobody will actually run it, and a signal or other external |
1677 | * event cannot wake it up and insert it on the runqueue either. | |
1678 | */ | |
0017d735 | 1679 | p->state = TASK_RUNNING; |
dd41f596 | 1680 | |
c350a04e MG |
1681 | /* |
1682 | * Make sure we do not leak PI boosting priority to the child. | |
1683 | */ | |
1684 | p->prio = current->normal_prio; | |
1685 | ||
b9dc29e7 MG |
1686 | /* |
1687 | * Revert to default priority/policy on fork if requested. | |
1688 | */ | |
1689 | if (unlikely(p->sched_reset_on_fork)) { | |
c350a04e | 1690 | if (task_has_rt_policy(p)) { |
b9dc29e7 | 1691 | p->policy = SCHED_NORMAL; |
6c697bdf | 1692 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
1693 | p->rt_priority = 0; |
1694 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
1695 | p->static_prio = NICE_TO_PRIO(0); | |
1696 | ||
1697 | p->prio = p->normal_prio = __normal_prio(p); | |
1698 | set_load_weight(p); | |
6c697bdf | 1699 | |
b9dc29e7 MG |
1700 | /* |
1701 | * We don't need the reset flag anymore after the fork. It has | |
1702 | * fulfilled its duty: | |
1703 | */ | |
1704 | p->sched_reset_on_fork = 0; | |
1705 | } | |
ca94c442 | 1706 | |
2ddbf952 HS |
1707 | if (!rt_prio(p->prio)) |
1708 | p->sched_class = &fair_sched_class; | |
b29739f9 | 1709 | |
cd29fe6f PZ |
1710 | if (p->sched_class->task_fork) |
1711 | p->sched_class->task_fork(p); | |
1712 | ||
86951599 PZ |
1713 | /* |
1714 | * The child is not yet in the pid-hash so no cgroup attach races, | |
1715 | * and the cgroup is pinned to this child due to cgroup_fork() | |
1716 | * is ran before sched_fork(). | |
1717 | * | |
1718 | * Silence PROVE_RCU. | |
1719 | */ | |
0122ec5b | 1720 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 1721 | set_task_cpu(p, cpu); |
0122ec5b | 1722 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 1723 | |
52f17b6c | 1724 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 1725 | if (likely(sched_info_on())) |
52f17b6c | 1726 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 1727 | #endif |
3ca7a440 PZ |
1728 | #if defined(CONFIG_SMP) |
1729 | p->on_cpu = 0; | |
4866cde0 | 1730 | #endif |
bdd4e85d | 1731 | #ifdef CONFIG_PREEMPT_COUNT |
4866cde0 | 1732 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 1733 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 1734 | #endif |
806c09a7 | 1735 | #ifdef CONFIG_SMP |
917b627d | 1736 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
806c09a7 | 1737 | #endif |
917b627d | 1738 | |
476d139c | 1739 | put_cpu(); |
1da177e4 LT |
1740 | } |
1741 | ||
1742 | /* | |
1743 | * wake_up_new_task - wake up a newly created task for the first time. | |
1744 | * | |
1745 | * This function will do some initial scheduler statistics housekeeping | |
1746 | * that must be done for every newly created context, then puts the task | |
1747 | * on the runqueue and wakes it. | |
1748 | */ | |
3e51e3ed | 1749 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
1750 | { |
1751 | unsigned long flags; | |
dd41f596 | 1752 | struct rq *rq; |
fabf318e | 1753 | |
ab2515c4 | 1754 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
1755 | #ifdef CONFIG_SMP |
1756 | /* | |
1757 | * Fork balancing, do it here and not earlier because: | |
1758 | * - cpus_allowed can change in the fork path | |
1759 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 1760 | */ |
ab2515c4 | 1761 | set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); |
0017d735 PZ |
1762 | #endif |
1763 | ||
ab2515c4 | 1764 | rq = __task_rq_lock(p); |
cd29fe6f | 1765 | activate_task(rq, p, 0); |
fd2f4419 | 1766 | p->on_rq = 1; |
89363381 | 1767 | trace_sched_wakeup_new(p, true); |
a7558e01 | 1768 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 1769 | #ifdef CONFIG_SMP |
efbbd05a PZ |
1770 | if (p->sched_class->task_woken) |
1771 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 1772 | #endif |
0122ec5b | 1773 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
1774 | } |
1775 | ||
e107be36 AK |
1776 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1777 | ||
1778 | /** | |
80dd99b3 | 1779 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 1780 | * @notifier: notifier struct to register |
e107be36 AK |
1781 | */ |
1782 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
1783 | { | |
1784 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
1785 | } | |
1786 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
1787 | ||
1788 | /** | |
1789 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 1790 | * @notifier: notifier struct to unregister |
e107be36 AK |
1791 | * |
1792 | * This is safe to call from within a preemption notifier. | |
1793 | */ | |
1794 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
1795 | { | |
1796 | hlist_del(¬ifier->link); | |
1797 | } | |
1798 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
1799 | ||
1800 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
1801 | { | |
1802 | struct preempt_notifier *notifier; | |
1803 | struct hlist_node *node; | |
1804 | ||
1805 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
1806 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
1807 | } | |
1808 | ||
1809 | static void | |
1810 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
1811 | struct task_struct *next) | |
1812 | { | |
1813 | struct preempt_notifier *notifier; | |
1814 | struct hlist_node *node; | |
1815 | ||
1816 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
1817 | notifier->ops->sched_out(notifier, next); | |
1818 | } | |
1819 | ||
6d6bc0ad | 1820 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
1821 | |
1822 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
1823 | { | |
1824 | } | |
1825 | ||
1826 | static void | |
1827 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
1828 | struct task_struct *next) | |
1829 | { | |
1830 | } | |
1831 | ||
6d6bc0ad | 1832 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 1833 | |
4866cde0 NP |
1834 | /** |
1835 | * prepare_task_switch - prepare to switch tasks | |
1836 | * @rq: the runqueue preparing to switch | |
421cee29 | 1837 | * @prev: the current task that is being switched out |
4866cde0 NP |
1838 | * @next: the task we are going to switch to. |
1839 | * | |
1840 | * This is called with the rq lock held and interrupts off. It must | |
1841 | * be paired with a subsequent finish_task_switch after the context | |
1842 | * switch. | |
1843 | * | |
1844 | * prepare_task_switch sets up locking and calls architecture specific | |
1845 | * hooks. | |
1846 | */ | |
e107be36 AK |
1847 | static inline void |
1848 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
1849 | struct task_struct *next) | |
4866cde0 | 1850 | { |
fe4b04fa PZ |
1851 | sched_info_switch(prev, next); |
1852 | perf_event_task_sched_out(prev, next); | |
e107be36 | 1853 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
1854 | prepare_lock_switch(rq, next); |
1855 | prepare_arch_switch(next); | |
fe4b04fa | 1856 | trace_sched_switch(prev, next); |
4866cde0 NP |
1857 | } |
1858 | ||
1da177e4 LT |
1859 | /** |
1860 | * finish_task_switch - clean up after a task-switch | |
344babaa | 1861 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
1862 | * @prev: the thread we just switched away from. |
1863 | * | |
4866cde0 NP |
1864 | * finish_task_switch must be called after the context switch, paired |
1865 | * with a prepare_task_switch call before the context switch. | |
1866 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
1867 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
1868 | * |
1869 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 1870 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
1871 | * with the lock held can cause deadlocks; see schedule() for |
1872 | * details.) | |
1873 | */ | |
a9957449 | 1874 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
1875 | __releases(rq->lock) |
1876 | { | |
1da177e4 | 1877 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 1878 | long prev_state; |
1da177e4 LT |
1879 | |
1880 | rq->prev_mm = NULL; | |
1881 | ||
1882 | /* | |
1883 | * A task struct has one reference for the use as "current". | |
c394cc9f | 1884 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
1885 | * schedule one last time. The schedule call will never return, and |
1886 | * the scheduled task must drop that reference. | |
c394cc9f | 1887 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
1888 | * still held, otherwise prev could be scheduled on another cpu, die |
1889 | * there before we look at prev->state, and then the reference would | |
1890 | * be dropped twice. | |
1891 | * Manfred Spraul <manfred@colorfullife.com> | |
1892 | */ | |
55a101f8 | 1893 | prev_state = prev->state; |
4866cde0 | 1894 | finish_arch_switch(prev); |
8381f65d JI |
1895 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
1896 | local_irq_disable(); | |
1897 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
a8d757ef | 1898 | perf_event_task_sched_in(prev, current); |
8381f65d JI |
1899 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
1900 | local_irq_enable(); | |
1901 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 1902 | finish_lock_switch(rq, prev); |
e8fa1362 | 1903 | |
e107be36 | 1904 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
1905 | if (mm) |
1906 | mmdrop(mm); | |
c394cc9f | 1907 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 1908 | /* |
1909 | * Remove function-return probe instances associated with this | |
1910 | * task and put them back on the free list. | |
9761eea8 | 1911 | */ |
c6fd91f0 | 1912 | kprobe_flush_task(prev); |
1da177e4 | 1913 | put_task_struct(prev); |
c6fd91f0 | 1914 | } |
1da177e4 LT |
1915 | } |
1916 | ||
3f029d3c GH |
1917 | #ifdef CONFIG_SMP |
1918 | ||
1919 | /* assumes rq->lock is held */ | |
1920 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
1921 | { | |
1922 | if (prev->sched_class->pre_schedule) | |
1923 | prev->sched_class->pre_schedule(rq, prev); | |
1924 | } | |
1925 | ||
1926 | /* rq->lock is NOT held, but preemption is disabled */ | |
1927 | static inline void post_schedule(struct rq *rq) | |
1928 | { | |
1929 | if (rq->post_schedule) { | |
1930 | unsigned long flags; | |
1931 | ||
05fa785c | 1932 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
1933 | if (rq->curr->sched_class->post_schedule) |
1934 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 1935 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
1936 | |
1937 | rq->post_schedule = 0; | |
1938 | } | |
1939 | } | |
1940 | ||
1941 | #else | |
da19ab51 | 1942 | |
3f029d3c GH |
1943 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
1944 | { | |
1945 | } | |
1946 | ||
1947 | static inline void post_schedule(struct rq *rq) | |
1948 | { | |
1da177e4 LT |
1949 | } |
1950 | ||
3f029d3c GH |
1951 | #endif |
1952 | ||
1da177e4 LT |
1953 | /** |
1954 | * schedule_tail - first thing a freshly forked thread must call. | |
1955 | * @prev: the thread we just switched away from. | |
1956 | */ | |
36c8b586 | 1957 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
1958 | __releases(rq->lock) |
1959 | { | |
70b97a7f IM |
1960 | struct rq *rq = this_rq(); |
1961 | ||
4866cde0 | 1962 | finish_task_switch(rq, prev); |
da19ab51 | 1963 | |
3f029d3c GH |
1964 | /* |
1965 | * FIXME: do we need to worry about rq being invalidated by the | |
1966 | * task_switch? | |
1967 | */ | |
1968 | post_schedule(rq); | |
70b97a7f | 1969 | |
4866cde0 NP |
1970 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
1971 | /* In this case, finish_task_switch does not reenable preemption */ | |
1972 | preempt_enable(); | |
1973 | #endif | |
1da177e4 | 1974 | if (current->set_child_tid) |
b488893a | 1975 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
1976 | } |
1977 | ||
1978 | /* | |
1979 | * context_switch - switch to the new MM and the new | |
1980 | * thread's register state. | |
1981 | */ | |
dd41f596 | 1982 | static inline void |
70b97a7f | 1983 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 1984 | struct task_struct *next) |
1da177e4 | 1985 | { |
dd41f596 | 1986 | struct mm_struct *mm, *oldmm; |
1da177e4 | 1987 | |
e107be36 | 1988 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 1989 | |
dd41f596 IM |
1990 | mm = next->mm; |
1991 | oldmm = prev->active_mm; | |
9226d125 ZA |
1992 | /* |
1993 | * For paravirt, this is coupled with an exit in switch_to to | |
1994 | * combine the page table reload and the switch backend into | |
1995 | * one hypercall. | |
1996 | */ | |
224101ed | 1997 | arch_start_context_switch(prev); |
9226d125 | 1998 | |
31915ab4 | 1999 | if (!mm) { |
1da177e4 LT |
2000 | next->active_mm = oldmm; |
2001 | atomic_inc(&oldmm->mm_count); | |
2002 | enter_lazy_tlb(oldmm, next); | |
2003 | } else | |
2004 | switch_mm(oldmm, mm, next); | |
2005 | ||
31915ab4 | 2006 | if (!prev->mm) { |
1da177e4 | 2007 | prev->active_mm = NULL; |
1da177e4 LT |
2008 | rq->prev_mm = oldmm; |
2009 | } | |
3a5f5e48 IM |
2010 | /* |
2011 | * Since the runqueue lock will be released by the next | |
2012 | * task (which is an invalid locking op but in the case | |
2013 | * of the scheduler it's an obvious special-case), so we | |
2014 | * do an early lockdep release here: | |
2015 | */ | |
2016 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2017 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2018 | #endif |
1da177e4 LT |
2019 | |
2020 | /* Here we just switch the register state and the stack. */ | |
2021 | switch_to(prev, next, prev); | |
2022 | ||
dd41f596 IM |
2023 | barrier(); |
2024 | /* | |
2025 | * this_rq must be evaluated again because prev may have moved | |
2026 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2027 | * frame will be invalid. | |
2028 | */ | |
2029 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2030 | } |
2031 | ||
2032 | /* | |
2033 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2034 | * | |
2035 | * externally visible scheduler statistics: current number of runnable | |
2036 | * threads, current number of uninterruptible-sleeping threads, total | |
2037 | * number of context switches performed since bootup. | |
2038 | */ | |
2039 | unsigned long nr_running(void) | |
2040 | { | |
2041 | unsigned long i, sum = 0; | |
2042 | ||
2043 | for_each_online_cpu(i) | |
2044 | sum += cpu_rq(i)->nr_running; | |
2045 | ||
2046 | return sum; | |
f711f609 | 2047 | } |
1da177e4 LT |
2048 | |
2049 | unsigned long nr_uninterruptible(void) | |
f711f609 | 2050 | { |
1da177e4 | 2051 | unsigned long i, sum = 0; |
f711f609 | 2052 | |
0a945022 | 2053 | for_each_possible_cpu(i) |
1da177e4 | 2054 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
2055 | |
2056 | /* | |
1da177e4 LT |
2057 | * Since we read the counters lockless, it might be slightly |
2058 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 2059 | */ |
1da177e4 LT |
2060 | if (unlikely((long)sum < 0)) |
2061 | sum = 0; | |
f711f609 | 2062 | |
1da177e4 | 2063 | return sum; |
f711f609 | 2064 | } |
f711f609 | 2065 | |
1da177e4 | 2066 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2067 | { |
cc94abfc SR |
2068 | int i; |
2069 | unsigned long long sum = 0; | |
46cb4b7c | 2070 | |
0a945022 | 2071 | for_each_possible_cpu(i) |
1da177e4 | 2072 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2073 | |
1da177e4 LT |
2074 | return sum; |
2075 | } | |
483b4ee6 | 2076 | |
1da177e4 LT |
2077 | unsigned long nr_iowait(void) |
2078 | { | |
2079 | unsigned long i, sum = 0; | |
483b4ee6 | 2080 | |
0a945022 | 2081 | for_each_possible_cpu(i) |
1da177e4 | 2082 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2083 | |
1da177e4 LT |
2084 | return sum; |
2085 | } | |
483b4ee6 | 2086 | |
8c215bd3 | 2087 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 2088 | { |
8c215bd3 | 2089 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
2090 | return atomic_read(&this->nr_iowait); |
2091 | } | |
46cb4b7c | 2092 | |
69d25870 AV |
2093 | unsigned long this_cpu_load(void) |
2094 | { | |
2095 | struct rq *this = this_rq(); | |
2096 | return this->cpu_load[0]; | |
2097 | } | |
e790fb0b | 2098 | |
46cb4b7c | 2099 | |
dce48a84 TG |
2100 | /* Variables and functions for calc_load */ |
2101 | static atomic_long_t calc_load_tasks; | |
2102 | static unsigned long calc_load_update; | |
2103 | unsigned long avenrun[3]; | |
2104 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 2105 | |
74f5187a PZ |
2106 | static long calc_load_fold_active(struct rq *this_rq) |
2107 | { | |
2108 | long nr_active, delta = 0; | |
2109 | ||
2110 | nr_active = this_rq->nr_running; | |
2111 | nr_active += (long) this_rq->nr_uninterruptible; | |
2112 | ||
2113 | if (nr_active != this_rq->calc_load_active) { | |
2114 | delta = nr_active - this_rq->calc_load_active; | |
2115 | this_rq->calc_load_active = nr_active; | |
2116 | } | |
2117 | ||
2118 | return delta; | |
2119 | } | |
2120 | ||
0f004f5a PZ |
2121 | static unsigned long |
2122 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
2123 | { | |
2124 | load *= exp; | |
2125 | load += active * (FIXED_1 - exp); | |
2126 | load += 1UL << (FSHIFT - 1); | |
2127 | return load >> FSHIFT; | |
2128 | } | |
2129 | ||
74f5187a PZ |
2130 | #ifdef CONFIG_NO_HZ |
2131 | /* | |
2132 | * For NO_HZ we delay the active fold to the next LOAD_FREQ update. | |
2133 | * | |
2134 | * When making the ILB scale, we should try to pull this in as well. | |
2135 | */ | |
2136 | static atomic_long_t calc_load_tasks_idle; | |
2137 | ||
029632fb | 2138 | void calc_load_account_idle(struct rq *this_rq) |
74f5187a PZ |
2139 | { |
2140 | long delta; | |
2141 | ||
2142 | delta = calc_load_fold_active(this_rq); | |
2143 | if (delta) | |
2144 | atomic_long_add(delta, &calc_load_tasks_idle); | |
2145 | } | |
2146 | ||
2147 | static long calc_load_fold_idle(void) | |
2148 | { | |
2149 | long delta = 0; | |
2150 | ||
2151 | /* | |
2152 | * Its got a race, we don't care... | |
2153 | */ | |
2154 | if (atomic_long_read(&calc_load_tasks_idle)) | |
2155 | delta = atomic_long_xchg(&calc_load_tasks_idle, 0); | |
2156 | ||
2157 | return delta; | |
2158 | } | |
0f004f5a PZ |
2159 | |
2160 | /** | |
2161 | * fixed_power_int - compute: x^n, in O(log n) time | |
2162 | * | |
2163 | * @x: base of the power | |
2164 | * @frac_bits: fractional bits of @x | |
2165 | * @n: power to raise @x to. | |
2166 | * | |
2167 | * By exploiting the relation between the definition of the natural power | |
2168 | * function: x^n := x*x*...*x (x multiplied by itself for n times), and | |
2169 | * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i, | |
2170 | * (where: n_i \elem {0, 1}, the binary vector representing n), | |
2171 | * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is | |
2172 | * of course trivially computable in O(log_2 n), the length of our binary | |
2173 | * vector. | |
2174 | */ | |
2175 | static unsigned long | |
2176 | fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n) | |
2177 | { | |
2178 | unsigned long result = 1UL << frac_bits; | |
2179 | ||
2180 | if (n) for (;;) { | |
2181 | if (n & 1) { | |
2182 | result *= x; | |
2183 | result += 1UL << (frac_bits - 1); | |
2184 | result >>= frac_bits; | |
2185 | } | |
2186 | n >>= 1; | |
2187 | if (!n) | |
2188 | break; | |
2189 | x *= x; | |
2190 | x += 1UL << (frac_bits - 1); | |
2191 | x >>= frac_bits; | |
2192 | } | |
2193 | ||
2194 | return result; | |
2195 | } | |
2196 | ||
2197 | /* | |
2198 | * a1 = a0 * e + a * (1 - e) | |
2199 | * | |
2200 | * a2 = a1 * e + a * (1 - e) | |
2201 | * = (a0 * e + a * (1 - e)) * e + a * (1 - e) | |
2202 | * = a0 * e^2 + a * (1 - e) * (1 + e) | |
2203 | * | |
2204 | * a3 = a2 * e + a * (1 - e) | |
2205 | * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e) | |
2206 | * = a0 * e^3 + a * (1 - e) * (1 + e + e^2) | |
2207 | * | |
2208 | * ... | |
2209 | * | |
2210 | * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1] | |
2211 | * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e) | |
2212 | * = a0 * e^n + a * (1 - e^n) | |
2213 | * | |
2214 | * [1] application of the geometric series: | |
2215 | * | |
2216 | * n 1 - x^(n+1) | |
2217 | * S_n := \Sum x^i = ------------- | |
2218 | * i=0 1 - x | |
2219 | */ | |
2220 | static unsigned long | |
2221 | calc_load_n(unsigned long load, unsigned long exp, | |
2222 | unsigned long active, unsigned int n) | |
2223 | { | |
2224 | ||
2225 | return calc_load(load, fixed_power_int(exp, FSHIFT, n), active); | |
2226 | } | |
2227 | ||
2228 | /* | |
2229 | * NO_HZ can leave us missing all per-cpu ticks calling | |
2230 | * calc_load_account_active(), but since an idle CPU folds its delta into | |
2231 | * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold | |
2232 | * in the pending idle delta if our idle period crossed a load cycle boundary. | |
2233 | * | |
2234 | * Once we've updated the global active value, we need to apply the exponential | |
2235 | * weights adjusted to the number of cycles missed. | |
2236 | */ | |
2237 | static void calc_global_nohz(unsigned long ticks) | |
2238 | { | |
2239 | long delta, active, n; | |
2240 | ||
2241 | if (time_before(jiffies, calc_load_update)) | |
2242 | return; | |
2243 | ||
2244 | /* | |
2245 | * If we crossed a calc_load_update boundary, make sure to fold | |
2246 | * any pending idle changes, the respective CPUs might have | |
2247 | * missed the tick driven calc_load_account_active() update | |
2248 | * due to NO_HZ. | |
2249 | */ | |
2250 | delta = calc_load_fold_idle(); | |
2251 | if (delta) | |
2252 | atomic_long_add(delta, &calc_load_tasks); | |
2253 | ||
2254 | /* | |
2255 | * If we were idle for multiple load cycles, apply them. | |
2256 | */ | |
2257 | if (ticks >= LOAD_FREQ) { | |
2258 | n = ticks / LOAD_FREQ; | |
2259 | ||
2260 | active = atomic_long_read(&calc_load_tasks); | |
2261 | active = active > 0 ? active * FIXED_1 : 0; | |
2262 | ||
2263 | avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n); | |
2264 | avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n); | |
2265 | avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n); | |
2266 | ||
2267 | calc_load_update += n * LOAD_FREQ; | |
2268 | } | |
2269 | ||
2270 | /* | |
2271 | * Its possible the remainder of the above division also crosses | |
2272 | * a LOAD_FREQ period, the regular check in calc_global_load() | |
2273 | * which comes after this will take care of that. | |
2274 | * | |
2275 | * Consider us being 11 ticks before a cycle completion, and us | |
2276 | * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will | |
2277 | * age us 4 cycles, and the test in calc_global_load() will | |
2278 | * pick up the final one. | |
2279 | */ | |
2280 | } | |
74f5187a | 2281 | #else |
029632fb | 2282 | void calc_load_account_idle(struct rq *this_rq) |
74f5187a PZ |
2283 | { |
2284 | } | |
2285 | ||
2286 | static inline long calc_load_fold_idle(void) | |
2287 | { | |
2288 | return 0; | |
2289 | } | |
0f004f5a PZ |
2290 | |
2291 | static void calc_global_nohz(unsigned long ticks) | |
2292 | { | |
2293 | } | |
74f5187a PZ |
2294 | #endif |
2295 | ||
2d02494f TG |
2296 | /** |
2297 | * get_avenrun - get the load average array | |
2298 | * @loads: pointer to dest load array | |
2299 | * @offset: offset to add | |
2300 | * @shift: shift count to shift the result left | |
2301 | * | |
2302 | * These values are estimates at best, so no need for locking. | |
2303 | */ | |
2304 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
2305 | { | |
2306 | loads[0] = (avenrun[0] + offset) << shift; | |
2307 | loads[1] = (avenrun[1] + offset) << shift; | |
2308 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 2309 | } |
46cb4b7c | 2310 | |
46cb4b7c | 2311 | /* |
dce48a84 TG |
2312 | * calc_load - update the avenrun load estimates 10 ticks after the |
2313 | * CPUs have updated calc_load_tasks. | |
7835b98b | 2314 | */ |
0f004f5a | 2315 | void calc_global_load(unsigned long ticks) |
7835b98b | 2316 | { |
dce48a84 | 2317 | long active; |
1da177e4 | 2318 | |
0f004f5a PZ |
2319 | calc_global_nohz(ticks); |
2320 | ||
2321 | if (time_before(jiffies, calc_load_update + 10)) | |
dce48a84 | 2322 | return; |
1da177e4 | 2323 | |
dce48a84 TG |
2324 | active = atomic_long_read(&calc_load_tasks); |
2325 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 2326 | |
dce48a84 TG |
2327 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
2328 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
2329 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 2330 | |
dce48a84 TG |
2331 | calc_load_update += LOAD_FREQ; |
2332 | } | |
1da177e4 | 2333 | |
dce48a84 | 2334 | /* |
74f5187a PZ |
2335 | * Called from update_cpu_load() to periodically update this CPU's |
2336 | * active count. | |
dce48a84 TG |
2337 | */ |
2338 | static void calc_load_account_active(struct rq *this_rq) | |
2339 | { | |
74f5187a | 2340 | long delta; |
08c183f3 | 2341 | |
74f5187a PZ |
2342 | if (time_before(jiffies, this_rq->calc_load_update)) |
2343 | return; | |
783609c6 | 2344 | |
74f5187a PZ |
2345 | delta = calc_load_fold_active(this_rq); |
2346 | delta += calc_load_fold_idle(); | |
2347 | if (delta) | |
dce48a84 | 2348 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
2349 | |
2350 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
2351 | } |
2352 | ||
fdf3e95d VP |
2353 | /* |
2354 | * The exact cpuload at various idx values, calculated at every tick would be | |
2355 | * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load | |
2356 | * | |
2357 | * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called | |
2358 | * on nth tick when cpu may be busy, then we have: | |
2359 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
2360 | * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load | |
2361 | * | |
2362 | * decay_load_missed() below does efficient calculation of | |
2363 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
2364 | * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load | |
2365 | * | |
2366 | * The calculation is approximated on a 128 point scale. | |
2367 | * degrade_zero_ticks is the number of ticks after which load at any | |
2368 | * particular idx is approximated to be zero. | |
2369 | * degrade_factor is a precomputed table, a row for each load idx. | |
2370 | * Each column corresponds to degradation factor for a power of two ticks, | |
2371 | * based on 128 point scale. | |
2372 | * Example: | |
2373 | * row 2, col 3 (=12) says that the degradation at load idx 2 after | |
2374 | * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8). | |
2375 | * | |
2376 | * With this power of 2 load factors, we can degrade the load n times | |
2377 | * by looking at 1 bits in n and doing as many mult/shift instead of | |
2378 | * n mult/shifts needed by the exact degradation. | |
2379 | */ | |
2380 | #define DEGRADE_SHIFT 7 | |
2381 | static const unsigned char | |
2382 | degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; | |
2383 | static const unsigned char | |
2384 | degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { | |
2385 | {0, 0, 0, 0, 0, 0, 0, 0}, | |
2386 | {64, 32, 8, 0, 0, 0, 0, 0}, | |
2387 | {96, 72, 40, 12, 1, 0, 0}, | |
2388 | {112, 98, 75, 43, 15, 1, 0}, | |
2389 | {120, 112, 98, 76, 45, 16, 2} }; | |
2390 | ||
2391 | /* | |
2392 | * Update cpu_load for any missed ticks, due to tickless idle. The backlog | |
2393 | * would be when CPU is idle and so we just decay the old load without | |
2394 | * adding any new load. | |
2395 | */ | |
2396 | static unsigned long | |
2397 | decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) | |
2398 | { | |
2399 | int j = 0; | |
2400 | ||
2401 | if (!missed_updates) | |
2402 | return load; | |
2403 | ||
2404 | if (missed_updates >= degrade_zero_ticks[idx]) | |
2405 | return 0; | |
2406 | ||
2407 | if (idx == 1) | |
2408 | return load >> missed_updates; | |
2409 | ||
2410 | while (missed_updates) { | |
2411 | if (missed_updates % 2) | |
2412 | load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; | |
2413 | ||
2414 | missed_updates >>= 1; | |
2415 | j++; | |
2416 | } | |
2417 | return load; | |
2418 | } | |
2419 | ||
46cb4b7c | 2420 | /* |
dd41f596 | 2421 | * Update rq->cpu_load[] statistics. This function is usually called every |
fdf3e95d VP |
2422 | * scheduler tick (TICK_NSEC). With tickless idle this will not be called |
2423 | * every tick. We fix it up based on jiffies. | |
46cb4b7c | 2424 | */ |
029632fb | 2425 | void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 2426 | { |
495eca49 | 2427 | unsigned long this_load = this_rq->load.weight; |
fdf3e95d VP |
2428 | unsigned long curr_jiffies = jiffies; |
2429 | unsigned long pending_updates; | |
dd41f596 | 2430 | int i, scale; |
46cb4b7c | 2431 | |
dd41f596 | 2432 | this_rq->nr_load_updates++; |
46cb4b7c | 2433 | |
fdf3e95d VP |
2434 | /* Avoid repeated calls on same jiffy, when moving in and out of idle */ |
2435 | if (curr_jiffies == this_rq->last_load_update_tick) | |
2436 | return; | |
2437 | ||
2438 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
2439 | this_rq->last_load_update_tick = curr_jiffies; | |
2440 | ||
dd41f596 | 2441 | /* Update our load: */ |
fdf3e95d VP |
2442 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
2443 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
dd41f596 | 2444 | unsigned long old_load, new_load; |
7d1e6a9b | 2445 | |
dd41f596 | 2446 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 2447 | |
dd41f596 | 2448 | old_load = this_rq->cpu_load[i]; |
fdf3e95d | 2449 | old_load = decay_load_missed(old_load, pending_updates - 1, i); |
dd41f596 | 2450 | new_load = this_load; |
a25707f3 IM |
2451 | /* |
2452 | * Round up the averaging division if load is increasing. This | |
2453 | * prevents us from getting stuck on 9 if the load is 10, for | |
2454 | * example. | |
2455 | */ | |
2456 | if (new_load > old_load) | |
fdf3e95d VP |
2457 | new_load += scale - 1; |
2458 | ||
2459 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | |
dd41f596 | 2460 | } |
da2b71ed SS |
2461 | |
2462 | sched_avg_update(this_rq); | |
fdf3e95d VP |
2463 | } |
2464 | ||
2465 | static void update_cpu_load_active(struct rq *this_rq) | |
2466 | { | |
2467 | update_cpu_load(this_rq); | |
46cb4b7c | 2468 | |
74f5187a | 2469 | calc_load_account_active(this_rq); |
46cb4b7c SS |
2470 | } |
2471 | ||
dd41f596 | 2472 | #ifdef CONFIG_SMP |
8a0be9ef | 2473 | |
46cb4b7c | 2474 | /* |
38022906 PZ |
2475 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2476 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 2477 | */ |
38022906 | 2478 | void sched_exec(void) |
46cb4b7c | 2479 | { |
38022906 | 2480 | struct task_struct *p = current; |
1da177e4 | 2481 | unsigned long flags; |
0017d735 | 2482 | int dest_cpu; |
46cb4b7c | 2483 | |
8f42ced9 | 2484 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
7608dec2 | 2485 | dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); |
0017d735 PZ |
2486 | if (dest_cpu == smp_processor_id()) |
2487 | goto unlock; | |
38022906 | 2488 | |
8f42ced9 | 2489 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 2490 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 2491 | |
8f42ced9 PZ |
2492 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2493 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
2494 | return; |
2495 | } | |
0017d735 | 2496 | unlock: |
8f42ced9 | 2497 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 2498 | } |
dd41f596 | 2499 | |
1da177e4 LT |
2500 | #endif |
2501 | ||
1da177e4 | 2502 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3292beb3 | 2503 | DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); |
1da177e4 LT |
2504 | |
2505 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3292beb3 | 2506 | EXPORT_PER_CPU_SYMBOL(kernel_cpustat); |
1da177e4 LT |
2507 | |
2508 | /* | |
c5f8d995 | 2509 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 2510 | * @p in case that task is currently running. |
c5f8d995 HS |
2511 | * |
2512 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 2513 | */ |
c5f8d995 HS |
2514 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
2515 | { | |
2516 | u64 ns = 0; | |
2517 | ||
2518 | if (task_current(rq, p)) { | |
2519 | update_rq_clock(rq); | |
305e6835 | 2520 | ns = rq->clock_task - p->se.exec_start; |
c5f8d995 HS |
2521 | if ((s64)ns < 0) |
2522 | ns = 0; | |
2523 | } | |
2524 | ||
2525 | return ns; | |
2526 | } | |
2527 | ||
bb34d92f | 2528 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 2529 | { |
1da177e4 | 2530 | unsigned long flags; |
41b86e9c | 2531 | struct rq *rq; |
bb34d92f | 2532 | u64 ns = 0; |
48f24c4d | 2533 | |
41b86e9c | 2534 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 2535 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 2536 | task_rq_unlock(rq, p, &flags); |
1508487e | 2537 | |
c5f8d995 HS |
2538 | return ns; |
2539 | } | |
f06febc9 | 2540 | |
c5f8d995 HS |
2541 | /* |
2542 | * Return accounted runtime for the task. | |
2543 | * In case the task is currently running, return the runtime plus current's | |
2544 | * pending runtime that have not been accounted yet. | |
2545 | */ | |
2546 | unsigned long long task_sched_runtime(struct task_struct *p) | |
2547 | { | |
2548 | unsigned long flags; | |
2549 | struct rq *rq; | |
2550 | u64 ns = 0; | |
2551 | ||
2552 | rq = task_rq_lock(p, &flags); | |
2553 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 2554 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
2555 | |
2556 | return ns; | |
2557 | } | |
48f24c4d | 2558 | |
54c707e9 GC |
2559 | #ifdef CONFIG_CGROUP_CPUACCT |
2560 | struct cgroup_subsys cpuacct_subsys; | |
2561 | struct cpuacct root_cpuacct; | |
2562 | #endif | |
2563 | ||
be726ffd GC |
2564 | static inline void task_group_account_field(struct task_struct *p, int index, |
2565 | u64 tmp) | |
54c707e9 GC |
2566 | { |
2567 | #ifdef CONFIG_CGROUP_CPUACCT | |
2568 | struct kernel_cpustat *kcpustat; | |
2569 | struct cpuacct *ca; | |
2570 | #endif | |
2571 | /* | |
2572 | * Since all updates are sure to touch the root cgroup, we | |
2573 | * get ourselves ahead and touch it first. If the root cgroup | |
2574 | * is the only cgroup, then nothing else should be necessary. | |
2575 | * | |
2576 | */ | |
2577 | __get_cpu_var(kernel_cpustat).cpustat[index] += tmp; | |
2578 | ||
2579 | #ifdef CONFIG_CGROUP_CPUACCT | |
2580 | if (unlikely(!cpuacct_subsys.active)) | |
2581 | return; | |
2582 | ||
2583 | rcu_read_lock(); | |
2584 | ca = task_ca(p); | |
2585 | while (ca && (ca != &root_cpuacct)) { | |
2586 | kcpustat = this_cpu_ptr(ca->cpustat); | |
2587 | kcpustat->cpustat[index] += tmp; | |
2588 | ca = parent_ca(ca); | |
2589 | } | |
2590 | rcu_read_unlock(); | |
2591 | #endif | |
2592 | } | |
2593 | ||
2594 | ||
1da177e4 LT |
2595 | /* |
2596 | * Account user cpu time to a process. | |
2597 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 2598 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 2599 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 2600 | */ |
457533a7 MS |
2601 | void account_user_time(struct task_struct *p, cputime_t cputime, |
2602 | cputime_t cputime_scaled) | |
1da177e4 | 2603 | { |
3292beb3 | 2604 | int index; |
1da177e4 | 2605 | |
457533a7 | 2606 | /* Add user time to process. */ |
1da177e4 | 2607 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 2608 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 2609 | account_group_user_time(p, cputime); |
1da177e4 | 2610 | |
3292beb3 | 2611 | index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; |
ef12fefa | 2612 | |
1c77f38a | 2613 | /* Add user time to cpustat. */ |
54c707e9 | 2614 | task_group_account_field(p, index, cputime); |
1c77f38a | 2615 | |
49b5cf34 JL |
2616 | /* Account for user time used */ |
2617 | acct_update_integrals(p); | |
1da177e4 LT |
2618 | } |
2619 | ||
94886b84 LV |
2620 | /* |
2621 | * Account guest cpu time to a process. | |
2622 | * @p: the process that the cpu time gets accounted to | |
2623 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 2624 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 2625 | */ |
457533a7 MS |
2626 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
2627 | cputime_t cputime_scaled) | |
94886b84 | 2628 | { |
3292beb3 GC |
2629 | u64 tmp; |
2630 | u64 *cpustat = kcpustat_this_cpu->cpustat; | |
94886b84 LV |
2631 | |
2632 | tmp = cputime_to_cputime64(cputime); | |
2633 | ||
457533a7 | 2634 | /* Add guest time to process. */ |
94886b84 | 2635 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 2636 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 2637 | account_group_user_time(p, cputime); |
94886b84 LV |
2638 | p->gtime = cputime_add(p->gtime, cputime); |
2639 | ||
457533a7 | 2640 | /* Add guest time to cpustat. */ |
ce0e7b28 | 2641 | if (TASK_NICE(p) > 0) { |
3292beb3 GC |
2642 | cpustat[CPUTIME_NICE] += tmp; |
2643 | cpustat[CPUTIME_GUEST_NICE] += tmp; | |
ce0e7b28 | 2644 | } else { |
3292beb3 GC |
2645 | cpustat[CPUTIME_USER] += tmp; |
2646 | cpustat[CPUTIME_GUEST] += tmp; | |
ce0e7b28 | 2647 | } |
94886b84 LV |
2648 | } |
2649 | ||
70a89a66 VP |
2650 | /* |
2651 | * Account system cpu time to a process and desired cpustat field | |
2652 | * @p: the process that the cpu time gets accounted to | |
2653 | * @cputime: the cpu time spent in kernel space since the last update | |
2654 | * @cputime_scaled: cputime scaled by cpu frequency | |
2655 | * @target_cputime64: pointer to cpustat field that has to be updated | |
2656 | */ | |
2657 | static inline | |
2658 | void __account_system_time(struct task_struct *p, cputime_t cputime, | |
3292beb3 | 2659 | cputime_t cputime_scaled, int index) |
70a89a66 | 2660 | { |
70a89a66 VP |
2661 | /* Add system time to process. */ |
2662 | p->stime = cputime_add(p->stime, cputime); | |
2663 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); | |
2664 | account_group_system_time(p, cputime); | |
2665 | ||
2666 | /* Add system time to cpustat. */ | |
54c707e9 | 2667 | task_group_account_field(p, index, cputime); |
70a89a66 VP |
2668 | |
2669 | /* Account for system time used */ | |
2670 | acct_update_integrals(p); | |
2671 | } | |
2672 | ||
1da177e4 LT |
2673 | /* |
2674 | * Account system cpu time to a process. | |
2675 | * @p: the process that the cpu time gets accounted to | |
2676 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
2677 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 2678 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
2679 | */ |
2680 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 2681 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 | 2682 | { |
3292beb3 | 2683 | int index; |
1da177e4 | 2684 | |
983ed7a6 | 2685 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 2686 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
2687 | return; |
2688 | } | |
94886b84 | 2689 | |
1da177e4 | 2690 | if (hardirq_count() - hardirq_offset) |
3292beb3 | 2691 | index = CPUTIME_IRQ; |
75e1056f | 2692 | else if (in_serving_softirq()) |
3292beb3 | 2693 | index = CPUTIME_SOFTIRQ; |
1da177e4 | 2694 | else |
3292beb3 | 2695 | index = CPUTIME_SYSTEM; |
ef12fefa | 2696 | |
3292beb3 | 2697 | __account_system_time(p, cputime, cputime_scaled, index); |
1da177e4 LT |
2698 | } |
2699 | ||
c66f08be | 2700 | /* |
1da177e4 | 2701 | * Account for involuntary wait time. |
544b4a1f | 2702 | * @cputime: the cpu time spent in involuntary wait |
c66f08be | 2703 | */ |
79741dd3 | 2704 | void account_steal_time(cputime_t cputime) |
c66f08be | 2705 | { |
3292beb3 GC |
2706 | u64 *cpustat = kcpustat_this_cpu->cpustat; |
2707 | u64 cputime64 = cputime_to_cputime64(cputime); | |
79741dd3 | 2708 | |
3292beb3 | 2709 | cpustat[CPUTIME_STEAL] += cputime64; |
c66f08be MN |
2710 | } |
2711 | ||
1da177e4 | 2712 | /* |
79741dd3 MS |
2713 | * Account for idle time. |
2714 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 2715 | */ |
79741dd3 | 2716 | void account_idle_time(cputime_t cputime) |
1da177e4 | 2717 | { |
3292beb3 GC |
2718 | u64 *cpustat = kcpustat_this_cpu->cpustat; |
2719 | u64 cputime64 = cputime_to_cputime64(cputime); | |
70b97a7f | 2720 | struct rq *rq = this_rq(); |
1da177e4 | 2721 | |
79741dd3 | 2722 | if (atomic_read(&rq->nr_iowait) > 0) |
3292beb3 | 2723 | cpustat[CPUTIME_IOWAIT] += cputime64; |
79741dd3 | 2724 | else |
3292beb3 | 2725 | cpustat[CPUTIME_IDLE] += cputime64; |
1da177e4 LT |
2726 | } |
2727 | ||
e6e6685a GC |
2728 | static __always_inline bool steal_account_process_tick(void) |
2729 | { | |
2730 | #ifdef CONFIG_PARAVIRT | |
2731 | if (static_branch(¶virt_steal_enabled)) { | |
2732 | u64 steal, st = 0; | |
2733 | ||
2734 | steal = paravirt_steal_clock(smp_processor_id()); | |
2735 | steal -= this_rq()->prev_steal_time; | |
2736 | ||
2737 | st = steal_ticks(steal); | |
2738 | this_rq()->prev_steal_time += st * TICK_NSEC; | |
2739 | ||
2740 | account_steal_time(st); | |
2741 | return st; | |
2742 | } | |
2743 | #endif | |
2744 | return false; | |
2745 | } | |
2746 | ||
79741dd3 MS |
2747 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
2748 | ||
abb74cef VP |
2749 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
2750 | /* | |
2751 | * Account a tick to a process and cpustat | |
2752 | * @p: the process that the cpu time gets accounted to | |
2753 | * @user_tick: is the tick from userspace | |
2754 | * @rq: the pointer to rq | |
2755 | * | |
2756 | * Tick demultiplexing follows the order | |
2757 | * - pending hardirq update | |
2758 | * - pending softirq update | |
2759 | * - user_time | |
2760 | * - idle_time | |
2761 | * - system time | |
2762 | * - check for guest_time | |
2763 | * - else account as system_time | |
2764 | * | |
2765 | * Check for hardirq is done both for system and user time as there is | |
2766 | * no timer going off while we are on hardirq and hence we may never get an | |
2767 | * opportunity to update it solely in system time. | |
2768 | * p->stime and friends are only updated on system time and not on irq | |
2769 | * softirq as those do not count in task exec_runtime any more. | |
2770 | */ | |
2771 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
2772 | struct rq *rq) | |
2773 | { | |
2774 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); | |
3292beb3 GC |
2775 | u64 tmp = cputime_to_cputime64(cputime_one_jiffy); |
2776 | u64 *cpustat = kcpustat_this_cpu->cpustat; | |
abb74cef | 2777 | |
e6e6685a GC |
2778 | if (steal_account_process_tick()) |
2779 | return; | |
2780 | ||
abb74cef | 2781 | if (irqtime_account_hi_update()) { |
3292beb3 | 2782 | cpustat[CPUTIME_IRQ] += tmp; |
abb74cef | 2783 | } else if (irqtime_account_si_update()) { |
3292beb3 | 2784 | cpustat[CPUTIME_SOFTIRQ] += tmp; |
414bee9b VP |
2785 | } else if (this_cpu_ksoftirqd() == p) { |
2786 | /* | |
2787 | * ksoftirqd time do not get accounted in cpu_softirq_time. | |
2788 | * So, we have to handle it separately here. | |
2789 | * Also, p->stime needs to be updated for ksoftirqd. | |
2790 | */ | |
2791 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
3292beb3 | 2792 | CPUTIME_SOFTIRQ); |
abb74cef VP |
2793 | } else if (user_tick) { |
2794 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
2795 | } else if (p == rq->idle) { | |
2796 | account_idle_time(cputime_one_jiffy); | |
2797 | } else if (p->flags & PF_VCPU) { /* System time or guest time */ | |
2798 | account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
2799 | } else { | |
2800 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
3292beb3 | 2801 | CPUTIME_SYSTEM); |
abb74cef VP |
2802 | } |
2803 | } | |
2804 | ||
2805 | static void irqtime_account_idle_ticks(int ticks) | |
2806 | { | |
2807 | int i; | |
2808 | struct rq *rq = this_rq(); | |
2809 | ||
2810 | for (i = 0; i < ticks; i++) | |
2811 | irqtime_account_process_tick(current, 0, rq); | |
2812 | } | |
544b4a1f | 2813 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
abb74cef VP |
2814 | static void irqtime_account_idle_ticks(int ticks) {} |
2815 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
2816 | struct rq *rq) {} | |
544b4a1f | 2817 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
79741dd3 MS |
2818 | |
2819 | /* | |
2820 | * Account a single tick of cpu time. | |
2821 | * @p: the process that the cpu time gets accounted to | |
2822 | * @user_tick: indicates if the tick is a user or a system tick | |
2823 | */ | |
2824 | void account_process_tick(struct task_struct *p, int user_tick) | |
2825 | { | |
a42548a1 | 2826 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
2827 | struct rq *rq = this_rq(); |
2828 | ||
abb74cef VP |
2829 | if (sched_clock_irqtime) { |
2830 | irqtime_account_process_tick(p, user_tick, rq); | |
2831 | return; | |
2832 | } | |
2833 | ||
e6e6685a GC |
2834 | if (steal_account_process_tick()) |
2835 | return; | |
2836 | ||
79741dd3 | 2837 | if (user_tick) |
a42548a1 | 2838 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 2839 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 2840 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
2841 | one_jiffy_scaled); |
2842 | else | |
a42548a1 | 2843 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
2844 | } |
2845 | ||
2846 | /* | |
2847 | * Account multiple ticks of steal time. | |
2848 | * @p: the process from which the cpu time has been stolen | |
2849 | * @ticks: number of stolen ticks | |
2850 | */ | |
2851 | void account_steal_ticks(unsigned long ticks) | |
2852 | { | |
2853 | account_steal_time(jiffies_to_cputime(ticks)); | |
2854 | } | |
2855 | ||
2856 | /* | |
2857 | * Account multiple ticks of idle time. | |
2858 | * @ticks: number of stolen ticks | |
2859 | */ | |
2860 | void account_idle_ticks(unsigned long ticks) | |
2861 | { | |
abb74cef VP |
2862 | |
2863 | if (sched_clock_irqtime) { | |
2864 | irqtime_account_idle_ticks(ticks); | |
2865 | return; | |
2866 | } | |
2867 | ||
79741dd3 | 2868 | account_idle_time(jiffies_to_cputime(ticks)); |
1da177e4 LT |
2869 | } |
2870 | ||
79741dd3 MS |
2871 | #endif |
2872 | ||
49048622 BS |
2873 | /* |
2874 | * Use precise platform statistics if available: | |
2875 | */ | |
2876 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 2877 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 2878 | { |
d99ca3b9 HS |
2879 | *ut = p->utime; |
2880 | *st = p->stime; | |
49048622 BS |
2881 | } |
2882 | ||
0cf55e1e | 2883 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 2884 | { |
0cf55e1e HS |
2885 | struct task_cputime cputime; |
2886 | ||
2887 | thread_group_cputime(p, &cputime); | |
2888 | ||
2889 | *ut = cputime.utime; | |
2890 | *st = cputime.stime; | |
49048622 BS |
2891 | } |
2892 | #else | |
761b1d26 HS |
2893 | |
2894 | #ifndef nsecs_to_cputime | |
b7b20df9 | 2895 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
2896 | #endif |
2897 | ||
d180c5bc | 2898 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 2899 | { |
d99ca3b9 | 2900 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
2901 | |
2902 | /* | |
2903 | * Use CFS's precise accounting: | |
2904 | */ | |
d180c5bc | 2905 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
2906 | |
2907 | if (total) { | |
e75e863d | 2908 | u64 temp = rtime; |
d180c5bc | 2909 | |
e75e863d | 2910 | temp *= utime; |
49048622 | 2911 | do_div(temp, total); |
d180c5bc HS |
2912 | utime = (cputime_t)temp; |
2913 | } else | |
2914 | utime = rtime; | |
49048622 | 2915 | |
d180c5bc HS |
2916 | /* |
2917 | * Compare with previous values, to keep monotonicity: | |
2918 | */ | |
761b1d26 | 2919 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 2920 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 2921 | |
d99ca3b9 HS |
2922 | *ut = p->prev_utime; |
2923 | *st = p->prev_stime; | |
49048622 BS |
2924 | } |
2925 | ||
0cf55e1e HS |
2926 | /* |
2927 | * Must be called with siglock held. | |
2928 | */ | |
2929 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 2930 | { |
0cf55e1e HS |
2931 | struct signal_struct *sig = p->signal; |
2932 | struct task_cputime cputime; | |
2933 | cputime_t rtime, utime, total; | |
49048622 | 2934 | |
0cf55e1e | 2935 | thread_group_cputime(p, &cputime); |
49048622 | 2936 | |
0cf55e1e HS |
2937 | total = cputime_add(cputime.utime, cputime.stime); |
2938 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 2939 | |
0cf55e1e | 2940 | if (total) { |
e75e863d | 2941 | u64 temp = rtime; |
49048622 | 2942 | |
e75e863d | 2943 | temp *= cputime.utime; |
0cf55e1e HS |
2944 | do_div(temp, total); |
2945 | utime = (cputime_t)temp; | |
2946 | } else | |
2947 | utime = rtime; | |
2948 | ||
2949 | sig->prev_utime = max(sig->prev_utime, utime); | |
2950 | sig->prev_stime = max(sig->prev_stime, | |
2951 | cputime_sub(rtime, sig->prev_utime)); | |
2952 | ||
2953 | *ut = sig->prev_utime; | |
2954 | *st = sig->prev_stime; | |
49048622 | 2955 | } |
49048622 | 2956 | #endif |
49048622 | 2957 | |
7835b98b CL |
2958 | /* |
2959 | * This function gets called by the timer code, with HZ frequency. | |
2960 | * We call it with interrupts disabled. | |
7835b98b CL |
2961 | */ |
2962 | void scheduler_tick(void) | |
2963 | { | |
7835b98b CL |
2964 | int cpu = smp_processor_id(); |
2965 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 2966 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
2967 | |
2968 | sched_clock_tick(); | |
dd41f596 | 2969 | |
05fa785c | 2970 | raw_spin_lock(&rq->lock); |
3e51f33f | 2971 | update_rq_clock(rq); |
fdf3e95d | 2972 | update_cpu_load_active(rq); |
fa85ae24 | 2973 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 2974 | raw_spin_unlock(&rq->lock); |
7835b98b | 2975 | |
e9d2b064 | 2976 | perf_event_task_tick(); |
e220d2dc | 2977 | |
e418e1c2 | 2978 | #ifdef CONFIG_SMP |
6eb57e0d | 2979 | rq->idle_balance = idle_cpu(cpu); |
dd41f596 | 2980 | trigger_load_balance(rq, cpu); |
e418e1c2 | 2981 | #endif |
1da177e4 LT |
2982 | } |
2983 | ||
132380a0 | 2984 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
2985 | { |
2986 | if (in_lock_functions(addr)) { | |
2987 | addr = CALLER_ADDR2; | |
2988 | if (in_lock_functions(addr)) | |
2989 | addr = CALLER_ADDR3; | |
2990 | } | |
2991 | return addr; | |
2992 | } | |
1da177e4 | 2993 | |
7e49fcce SR |
2994 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
2995 | defined(CONFIG_PREEMPT_TRACER)) | |
2996 | ||
43627582 | 2997 | void __kprobes add_preempt_count(int val) |
1da177e4 | 2998 | { |
6cd8a4bb | 2999 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3000 | /* |
3001 | * Underflow? | |
3002 | */ | |
9a11b49a IM |
3003 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
3004 | return; | |
6cd8a4bb | 3005 | #endif |
1da177e4 | 3006 | preempt_count() += val; |
6cd8a4bb | 3007 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3008 | /* |
3009 | * Spinlock count overflowing soon? | |
3010 | */ | |
33859f7f MOS |
3011 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
3012 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
3013 | #endif |
3014 | if (preempt_count() == val) | |
3015 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3016 | } |
3017 | EXPORT_SYMBOL(add_preempt_count); | |
3018 | ||
43627582 | 3019 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 3020 | { |
6cd8a4bb | 3021 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3022 | /* |
3023 | * Underflow? | |
3024 | */ | |
01e3eb82 | 3025 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 3026 | return; |
1da177e4 LT |
3027 | /* |
3028 | * Is the spinlock portion underflowing? | |
3029 | */ | |
9a11b49a IM |
3030 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
3031 | !(preempt_count() & PREEMPT_MASK))) | |
3032 | return; | |
6cd8a4bb | 3033 | #endif |
9a11b49a | 3034 | |
6cd8a4bb SR |
3035 | if (preempt_count() == val) |
3036 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3037 | preempt_count() -= val; |
3038 | } | |
3039 | EXPORT_SYMBOL(sub_preempt_count); | |
3040 | ||
3041 | #endif | |
3042 | ||
3043 | /* | |
dd41f596 | 3044 | * Print scheduling while atomic bug: |
1da177e4 | 3045 | */ |
dd41f596 | 3046 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 3047 | { |
838225b4 SS |
3048 | struct pt_regs *regs = get_irq_regs(); |
3049 | ||
3df0fc5b PZ |
3050 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
3051 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 3052 | |
dd41f596 | 3053 | debug_show_held_locks(prev); |
e21f5b15 | 3054 | print_modules(); |
dd41f596 IM |
3055 | if (irqs_disabled()) |
3056 | print_irqtrace_events(prev); | |
838225b4 SS |
3057 | |
3058 | if (regs) | |
3059 | show_regs(regs); | |
3060 | else | |
3061 | dump_stack(); | |
dd41f596 | 3062 | } |
1da177e4 | 3063 | |
dd41f596 IM |
3064 | /* |
3065 | * Various schedule()-time debugging checks and statistics: | |
3066 | */ | |
3067 | static inline void schedule_debug(struct task_struct *prev) | |
3068 | { | |
1da177e4 | 3069 | /* |
41a2d6cf | 3070 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
3071 | * schedule() atomically, we ignore that path for now. |
3072 | * Otherwise, whine if we are scheduling when we should not be. | |
3073 | */ | |
3f33a7ce | 3074 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 | 3075 | __schedule_bug(prev); |
b3fbab05 | 3076 | rcu_sleep_check(); |
dd41f596 | 3077 | |
1da177e4 LT |
3078 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
3079 | ||
2d72376b | 3080 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
3081 | } |
3082 | ||
6cecd084 | 3083 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 3084 | { |
61eadef6 | 3085 | if (prev->on_rq || rq->skip_clock_update < 0) |
a64692a3 | 3086 | update_rq_clock(rq); |
6cecd084 | 3087 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
3088 | } |
3089 | ||
dd41f596 IM |
3090 | /* |
3091 | * Pick up the highest-prio task: | |
3092 | */ | |
3093 | static inline struct task_struct * | |
b67802ea | 3094 | pick_next_task(struct rq *rq) |
dd41f596 | 3095 | { |
5522d5d5 | 3096 | const struct sched_class *class; |
dd41f596 | 3097 | struct task_struct *p; |
1da177e4 LT |
3098 | |
3099 | /* | |
dd41f596 IM |
3100 | * Optimization: we know that if all tasks are in |
3101 | * the fair class we can call that function directly: | |
1da177e4 | 3102 | */ |
953bfcd1 | 3103 | if (likely(rq->nr_running == rq->cfs.h_nr_running)) { |
fb8d4724 | 3104 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
3105 | if (likely(p)) |
3106 | return p; | |
1da177e4 LT |
3107 | } |
3108 | ||
34f971f6 | 3109 | for_each_class(class) { |
fb8d4724 | 3110 | p = class->pick_next_task(rq); |
dd41f596 IM |
3111 | if (p) |
3112 | return p; | |
dd41f596 | 3113 | } |
34f971f6 PZ |
3114 | |
3115 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 3116 | } |
1da177e4 | 3117 | |
dd41f596 | 3118 | /* |
c259e01a | 3119 | * __schedule() is the main scheduler function. |
dd41f596 | 3120 | */ |
c259e01a | 3121 | static void __sched __schedule(void) |
dd41f596 IM |
3122 | { |
3123 | struct task_struct *prev, *next; | |
67ca7bde | 3124 | unsigned long *switch_count; |
dd41f596 | 3125 | struct rq *rq; |
31656519 | 3126 | int cpu; |
dd41f596 | 3127 | |
ff743345 PZ |
3128 | need_resched: |
3129 | preempt_disable(); | |
dd41f596 IM |
3130 | cpu = smp_processor_id(); |
3131 | rq = cpu_rq(cpu); | |
25502a6c | 3132 | rcu_note_context_switch(cpu); |
dd41f596 | 3133 | prev = rq->curr; |
dd41f596 | 3134 | |
dd41f596 | 3135 | schedule_debug(prev); |
1da177e4 | 3136 | |
31656519 | 3137 | if (sched_feat(HRTICK)) |
f333fdc9 | 3138 | hrtick_clear(rq); |
8f4d37ec | 3139 | |
05fa785c | 3140 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 3141 | |
246d86b5 | 3142 | switch_count = &prev->nivcsw; |
1da177e4 | 3143 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 3144 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 3145 | prev->state = TASK_RUNNING; |
21aa9af0 | 3146 | } else { |
2acca55e PZ |
3147 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
3148 | prev->on_rq = 0; | |
3149 | ||
21aa9af0 | 3150 | /* |
2acca55e PZ |
3151 | * If a worker went to sleep, notify and ask workqueue |
3152 | * whether it wants to wake up a task to maintain | |
3153 | * concurrency. | |
21aa9af0 TH |
3154 | */ |
3155 | if (prev->flags & PF_WQ_WORKER) { | |
3156 | struct task_struct *to_wakeup; | |
3157 | ||
3158 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
3159 | if (to_wakeup) | |
3160 | try_to_wake_up_local(to_wakeup); | |
3161 | } | |
21aa9af0 | 3162 | } |
dd41f596 | 3163 | switch_count = &prev->nvcsw; |
1da177e4 LT |
3164 | } |
3165 | ||
3f029d3c | 3166 | pre_schedule(rq, prev); |
f65eda4f | 3167 | |
dd41f596 | 3168 | if (unlikely(!rq->nr_running)) |
1da177e4 | 3169 | idle_balance(cpu, rq); |
1da177e4 | 3170 | |
df1c99d4 | 3171 | put_prev_task(rq, prev); |
b67802ea | 3172 | next = pick_next_task(rq); |
f26f9aff MG |
3173 | clear_tsk_need_resched(prev); |
3174 | rq->skip_clock_update = 0; | |
1da177e4 | 3175 | |
1da177e4 | 3176 | if (likely(prev != next)) { |
1da177e4 LT |
3177 | rq->nr_switches++; |
3178 | rq->curr = next; | |
3179 | ++*switch_count; | |
3180 | ||
dd41f596 | 3181 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 3182 | /* |
246d86b5 ON |
3183 | * The context switch have flipped the stack from under us |
3184 | * and restored the local variables which were saved when | |
3185 | * this task called schedule() in the past. prev == current | |
3186 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
3187 | */ |
3188 | cpu = smp_processor_id(); | |
3189 | rq = cpu_rq(cpu); | |
1da177e4 | 3190 | } else |
05fa785c | 3191 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 3192 | |
3f029d3c | 3193 | post_schedule(rq); |
1da177e4 | 3194 | |
1da177e4 | 3195 | preempt_enable_no_resched(); |
ff743345 | 3196 | if (need_resched()) |
1da177e4 LT |
3197 | goto need_resched; |
3198 | } | |
c259e01a | 3199 | |
9c40cef2 TG |
3200 | static inline void sched_submit_work(struct task_struct *tsk) |
3201 | { | |
3202 | if (!tsk->state) | |
3203 | return; | |
3204 | /* | |
3205 | * If we are going to sleep and we have plugged IO queued, | |
3206 | * make sure to submit it to avoid deadlocks. | |
3207 | */ | |
3208 | if (blk_needs_flush_plug(tsk)) | |
3209 | blk_schedule_flush_plug(tsk); | |
3210 | } | |
3211 | ||
6ebbe7a0 | 3212 | asmlinkage void __sched schedule(void) |
c259e01a | 3213 | { |
9c40cef2 TG |
3214 | struct task_struct *tsk = current; |
3215 | ||
3216 | sched_submit_work(tsk); | |
c259e01a TG |
3217 | __schedule(); |
3218 | } | |
1da177e4 LT |
3219 | EXPORT_SYMBOL(schedule); |
3220 | ||
c08f7829 | 3221 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d | 3222 | |
c6eb3dda PZ |
3223 | static inline bool owner_running(struct mutex *lock, struct task_struct *owner) |
3224 | { | |
c6eb3dda | 3225 | if (lock->owner != owner) |
307bf980 | 3226 | return false; |
0d66bf6d PZ |
3227 | |
3228 | /* | |
c6eb3dda PZ |
3229 | * Ensure we emit the owner->on_cpu, dereference _after_ checking |
3230 | * lock->owner still matches owner, if that fails, owner might | |
3231 | * point to free()d memory, if it still matches, the rcu_read_lock() | |
3232 | * ensures the memory stays valid. | |
0d66bf6d | 3233 | */ |
c6eb3dda | 3234 | barrier(); |
0d66bf6d | 3235 | |
307bf980 | 3236 | return owner->on_cpu; |
c6eb3dda | 3237 | } |
0d66bf6d | 3238 | |
c6eb3dda PZ |
3239 | /* |
3240 | * Look out! "owner" is an entirely speculative pointer | |
3241 | * access and not reliable. | |
3242 | */ | |
3243 | int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) | |
3244 | { | |
3245 | if (!sched_feat(OWNER_SPIN)) | |
3246 | return 0; | |
0d66bf6d | 3247 | |
307bf980 | 3248 | rcu_read_lock(); |
c6eb3dda PZ |
3249 | while (owner_running(lock, owner)) { |
3250 | if (need_resched()) | |
307bf980 | 3251 | break; |
0d66bf6d | 3252 | |
335d7afb | 3253 | arch_mutex_cpu_relax(); |
0d66bf6d | 3254 | } |
307bf980 | 3255 | rcu_read_unlock(); |
4b402210 | 3256 | |
c6eb3dda | 3257 | /* |
307bf980 TG |
3258 | * We break out the loop above on need_resched() and when the |
3259 | * owner changed, which is a sign for heavy contention. Return | |
3260 | * success only when lock->owner is NULL. | |
c6eb3dda | 3261 | */ |
307bf980 | 3262 | return lock->owner == NULL; |
0d66bf6d PZ |
3263 | } |
3264 | #endif | |
3265 | ||
1da177e4 LT |
3266 | #ifdef CONFIG_PREEMPT |
3267 | /* | |
2ed6e34f | 3268 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 3269 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
3270 | * occur there and call schedule directly. |
3271 | */ | |
d1f74e20 | 3272 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
3273 | { |
3274 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3275 | |
1da177e4 LT |
3276 | /* |
3277 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 3278 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 3279 | */ |
beed33a8 | 3280 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
3281 | return; |
3282 | ||
3a5c359a | 3283 | do { |
d1f74e20 | 3284 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
c259e01a | 3285 | __schedule(); |
d1f74e20 | 3286 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 3287 | |
3a5c359a AK |
3288 | /* |
3289 | * Check again in case we missed a preemption opportunity | |
3290 | * between schedule and now. | |
3291 | */ | |
3292 | barrier(); | |
5ed0cec0 | 3293 | } while (need_resched()); |
1da177e4 | 3294 | } |
1da177e4 LT |
3295 | EXPORT_SYMBOL(preempt_schedule); |
3296 | ||
3297 | /* | |
2ed6e34f | 3298 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
3299 | * off of irq context. |
3300 | * Note, that this is called and return with irqs disabled. This will | |
3301 | * protect us against recursive calling from irq. | |
3302 | */ | |
3303 | asmlinkage void __sched preempt_schedule_irq(void) | |
3304 | { | |
3305 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3306 | |
2ed6e34f | 3307 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
3308 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
3309 | ||
3a5c359a AK |
3310 | do { |
3311 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 3312 | local_irq_enable(); |
c259e01a | 3313 | __schedule(); |
3a5c359a | 3314 | local_irq_disable(); |
3a5c359a | 3315 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3316 | |
3a5c359a AK |
3317 | /* |
3318 | * Check again in case we missed a preemption opportunity | |
3319 | * between schedule and now. | |
3320 | */ | |
3321 | barrier(); | |
5ed0cec0 | 3322 | } while (need_resched()); |
1da177e4 LT |
3323 | } |
3324 | ||
3325 | #endif /* CONFIG_PREEMPT */ | |
3326 | ||
63859d4f | 3327 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3328 | void *key) |
1da177e4 | 3329 | { |
63859d4f | 3330 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3331 | } |
1da177e4 LT |
3332 | EXPORT_SYMBOL(default_wake_function); |
3333 | ||
3334 | /* | |
41a2d6cf IM |
3335 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
3336 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
3337 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
3338 | * | |
3339 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 3340 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
3341 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
3342 | */ | |
78ddb08f | 3343 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 3344 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 3345 | { |
2e45874c | 3346 | wait_queue_t *curr, *next; |
1da177e4 | 3347 | |
2e45874c | 3348 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
3349 | unsigned flags = curr->flags; |
3350 | ||
63859d4f | 3351 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 3352 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
3353 | break; |
3354 | } | |
3355 | } | |
3356 | ||
3357 | /** | |
3358 | * __wake_up - wake up threads blocked on a waitqueue. | |
3359 | * @q: the waitqueue | |
3360 | * @mode: which threads | |
3361 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 3362 | * @key: is directly passed to the wakeup function |
50fa610a DH |
3363 | * |
3364 | * It may be assumed that this function implies a write memory barrier before | |
3365 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3366 | */ |
7ad5b3a5 | 3367 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 3368 | int nr_exclusive, void *key) |
1da177e4 LT |
3369 | { |
3370 | unsigned long flags; | |
3371 | ||
3372 | spin_lock_irqsave(&q->lock, flags); | |
3373 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
3374 | spin_unlock_irqrestore(&q->lock, flags); | |
3375 | } | |
1da177e4 LT |
3376 | EXPORT_SYMBOL(__wake_up); |
3377 | ||
3378 | /* | |
3379 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
3380 | */ | |
7ad5b3a5 | 3381 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
3382 | { |
3383 | __wake_up_common(q, mode, 1, 0, NULL); | |
3384 | } | |
22c43c81 | 3385 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 3386 | |
4ede816a DL |
3387 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
3388 | { | |
3389 | __wake_up_common(q, mode, 1, 0, key); | |
3390 | } | |
bf294b41 | 3391 | EXPORT_SYMBOL_GPL(__wake_up_locked_key); |
4ede816a | 3392 | |
1da177e4 | 3393 | /** |
4ede816a | 3394 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
3395 | * @q: the waitqueue |
3396 | * @mode: which threads | |
3397 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 3398 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
3399 | * |
3400 | * The sync wakeup differs that the waker knows that it will schedule | |
3401 | * away soon, so while the target thread will be woken up, it will not | |
3402 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
3403 | * with each other. This can prevent needless bouncing between CPUs. | |
3404 | * | |
3405 | * On UP it can prevent extra preemption. | |
50fa610a DH |
3406 | * |
3407 | * It may be assumed that this function implies a write memory barrier before | |
3408 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3409 | */ |
4ede816a DL |
3410 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
3411 | int nr_exclusive, void *key) | |
1da177e4 LT |
3412 | { |
3413 | unsigned long flags; | |
7d478721 | 3414 | int wake_flags = WF_SYNC; |
1da177e4 LT |
3415 | |
3416 | if (unlikely(!q)) | |
3417 | return; | |
3418 | ||
3419 | if (unlikely(!nr_exclusive)) | |
7d478721 | 3420 | wake_flags = 0; |
1da177e4 LT |
3421 | |
3422 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 3423 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
3424 | spin_unlock_irqrestore(&q->lock, flags); |
3425 | } | |
4ede816a DL |
3426 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
3427 | ||
3428 | /* | |
3429 | * __wake_up_sync - see __wake_up_sync_key() | |
3430 | */ | |
3431 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
3432 | { | |
3433 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
3434 | } | |
1da177e4 LT |
3435 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
3436 | ||
65eb3dc6 KD |
3437 | /** |
3438 | * complete: - signals a single thread waiting on this completion | |
3439 | * @x: holds the state of this particular completion | |
3440 | * | |
3441 | * This will wake up a single thread waiting on this completion. Threads will be | |
3442 | * awakened in the same order in which they were queued. | |
3443 | * | |
3444 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
3445 | * |
3446 | * It may be assumed that this function implies a write memory barrier before | |
3447 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3448 | */ |
b15136e9 | 3449 | void complete(struct completion *x) |
1da177e4 LT |
3450 | { |
3451 | unsigned long flags; | |
3452 | ||
3453 | spin_lock_irqsave(&x->wait.lock, flags); | |
3454 | x->done++; | |
d9514f6c | 3455 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
3456 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3457 | } | |
3458 | EXPORT_SYMBOL(complete); | |
3459 | ||
65eb3dc6 KD |
3460 | /** |
3461 | * complete_all: - signals all threads waiting on this completion | |
3462 | * @x: holds the state of this particular completion | |
3463 | * | |
3464 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
3465 | * |
3466 | * It may be assumed that this function implies a write memory barrier before | |
3467 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3468 | */ |
b15136e9 | 3469 | void complete_all(struct completion *x) |
1da177e4 LT |
3470 | { |
3471 | unsigned long flags; | |
3472 | ||
3473 | spin_lock_irqsave(&x->wait.lock, flags); | |
3474 | x->done += UINT_MAX/2; | |
d9514f6c | 3475 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
3476 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3477 | } | |
3478 | EXPORT_SYMBOL(complete_all); | |
3479 | ||
8cbbe86d AK |
3480 | static inline long __sched |
3481 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3482 | { |
1da177e4 LT |
3483 | if (!x->done) { |
3484 | DECLARE_WAITQUEUE(wait, current); | |
3485 | ||
a93d2f17 | 3486 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 3487 | do { |
94d3d824 | 3488 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
3489 | timeout = -ERESTARTSYS; |
3490 | break; | |
8cbbe86d AK |
3491 | } |
3492 | __set_current_state(state); | |
1da177e4 LT |
3493 | spin_unlock_irq(&x->wait.lock); |
3494 | timeout = schedule_timeout(timeout); | |
3495 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 3496 | } while (!x->done && timeout); |
1da177e4 | 3497 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
3498 | if (!x->done) |
3499 | return timeout; | |
1da177e4 LT |
3500 | } |
3501 | x->done--; | |
ea71a546 | 3502 | return timeout ?: 1; |
1da177e4 | 3503 | } |
1da177e4 | 3504 | |
8cbbe86d AK |
3505 | static long __sched |
3506 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3507 | { |
1da177e4 LT |
3508 | might_sleep(); |
3509 | ||
3510 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 3511 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 3512 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
3513 | return timeout; |
3514 | } | |
1da177e4 | 3515 | |
65eb3dc6 KD |
3516 | /** |
3517 | * wait_for_completion: - waits for completion of a task | |
3518 | * @x: holds the state of this particular completion | |
3519 | * | |
3520 | * This waits to be signaled for completion of a specific task. It is NOT | |
3521 | * interruptible and there is no timeout. | |
3522 | * | |
3523 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
3524 | * and interrupt capability. Also see complete(). | |
3525 | */ | |
b15136e9 | 3526 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
3527 | { |
3528 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 3529 | } |
8cbbe86d | 3530 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 3531 | |
65eb3dc6 KD |
3532 | /** |
3533 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
3534 | * @x: holds the state of this particular completion | |
3535 | * @timeout: timeout value in jiffies | |
3536 | * | |
3537 | * This waits for either a completion of a specific task to be signaled or for a | |
3538 | * specified timeout to expire. The timeout is in jiffies. It is not | |
3539 | * interruptible. | |
c6dc7f05 BF |
3540 | * |
3541 | * The return value is 0 if timed out, and positive (at least 1, or number of | |
3542 | * jiffies left till timeout) if completed. | |
65eb3dc6 | 3543 | */ |
b15136e9 | 3544 | unsigned long __sched |
8cbbe86d | 3545 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 3546 | { |
8cbbe86d | 3547 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 3548 | } |
8cbbe86d | 3549 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 3550 | |
65eb3dc6 KD |
3551 | /** |
3552 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
3553 | * @x: holds the state of this particular completion | |
3554 | * | |
3555 | * This waits for completion of a specific task to be signaled. It is | |
3556 | * interruptible. | |
c6dc7f05 BF |
3557 | * |
3558 | * The return value is -ERESTARTSYS if interrupted, 0 if completed. | |
65eb3dc6 | 3559 | */ |
8cbbe86d | 3560 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 3561 | { |
51e97990 AK |
3562 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
3563 | if (t == -ERESTARTSYS) | |
3564 | return t; | |
3565 | return 0; | |
0fec171c | 3566 | } |
8cbbe86d | 3567 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 3568 | |
65eb3dc6 KD |
3569 | /** |
3570 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
3571 | * @x: holds the state of this particular completion | |
3572 | * @timeout: timeout value in jiffies | |
3573 | * | |
3574 | * This waits for either a completion of a specific task to be signaled or for a | |
3575 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
c6dc7f05 BF |
3576 | * |
3577 | * The return value is -ERESTARTSYS if interrupted, 0 if timed out, | |
3578 | * positive (at least 1, or number of jiffies left till timeout) if completed. | |
65eb3dc6 | 3579 | */ |
6bf41237 | 3580 | long __sched |
8cbbe86d AK |
3581 | wait_for_completion_interruptible_timeout(struct completion *x, |
3582 | unsigned long timeout) | |
0fec171c | 3583 | { |
8cbbe86d | 3584 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 3585 | } |
8cbbe86d | 3586 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 3587 | |
65eb3dc6 KD |
3588 | /** |
3589 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
3590 | * @x: holds the state of this particular completion | |
3591 | * | |
3592 | * This waits to be signaled for completion of a specific task. It can be | |
3593 | * interrupted by a kill signal. | |
c6dc7f05 BF |
3594 | * |
3595 | * The return value is -ERESTARTSYS if interrupted, 0 if completed. | |
65eb3dc6 | 3596 | */ |
009e577e MW |
3597 | int __sched wait_for_completion_killable(struct completion *x) |
3598 | { | |
3599 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
3600 | if (t == -ERESTARTSYS) | |
3601 | return t; | |
3602 | return 0; | |
3603 | } | |
3604 | EXPORT_SYMBOL(wait_for_completion_killable); | |
3605 | ||
0aa12fb4 SW |
3606 | /** |
3607 | * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) | |
3608 | * @x: holds the state of this particular completion | |
3609 | * @timeout: timeout value in jiffies | |
3610 | * | |
3611 | * This waits for either a completion of a specific task to be | |
3612 | * signaled or for a specified timeout to expire. It can be | |
3613 | * interrupted by a kill signal. The timeout is in jiffies. | |
c6dc7f05 BF |
3614 | * |
3615 | * The return value is -ERESTARTSYS if interrupted, 0 if timed out, | |
3616 | * positive (at least 1, or number of jiffies left till timeout) if completed. | |
0aa12fb4 | 3617 | */ |
6bf41237 | 3618 | long __sched |
0aa12fb4 SW |
3619 | wait_for_completion_killable_timeout(struct completion *x, |
3620 | unsigned long timeout) | |
3621 | { | |
3622 | return wait_for_common(x, timeout, TASK_KILLABLE); | |
3623 | } | |
3624 | EXPORT_SYMBOL(wait_for_completion_killable_timeout); | |
3625 | ||
be4de352 DC |
3626 | /** |
3627 | * try_wait_for_completion - try to decrement a completion without blocking | |
3628 | * @x: completion structure | |
3629 | * | |
3630 | * Returns: 0 if a decrement cannot be done without blocking | |
3631 | * 1 if a decrement succeeded. | |
3632 | * | |
3633 | * If a completion is being used as a counting completion, | |
3634 | * attempt to decrement the counter without blocking. This | |
3635 | * enables us to avoid waiting if the resource the completion | |
3636 | * is protecting is not available. | |
3637 | */ | |
3638 | bool try_wait_for_completion(struct completion *x) | |
3639 | { | |
7539a3b3 | 3640 | unsigned long flags; |
be4de352 DC |
3641 | int ret = 1; |
3642 | ||
7539a3b3 | 3643 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
3644 | if (!x->done) |
3645 | ret = 0; | |
3646 | else | |
3647 | x->done--; | |
7539a3b3 | 3648 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
3649 | return ret; |
3650 | } | |
3651 | EXPORT_SYMBOL(try_wait_for_completion); | |
3652 | ||
3653 | /** | |
3654 | * completion_done - Test to see if a completion has any waiters | |
3655 | * @x: completion structure | |
3656 | * | |
3657 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
3658 | * 1 if there are no waiters. | |
3659 | * | |
3660 | */ | |
3661 | bool completion_done(struct completion *x) | |
3662 | { | |
7539a3b3 | 3663 | unsigned long flags; |
be4de352 DC |
3664 | int ret = 1; |
3665 | ||
7539a3b3 | 3666 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
3667 | if (!x->done) |
3668 | ret = 0; | |
7539a3b3 | 3669 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
3670 | return ret; |
3671 | } | |
3672 | EXPORT_SYMBOL(completion_done); | |
3673 | ||
8cbbe86d AK |
3674 | static long __sched |
3675 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 3676 | { |
0fec171c IM |
3677 | unsigned long flags; |
3678 | wait_queue_t wait; | |
3679 | ||
3680 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 3681 | |
8cbbe86d | 3682 | __set_current_state(state); |
1da177e4 | 3683 | |
8cbbe86d AK |
3684 | spin_lock_irqsave(&q->lock, flags); |
3685 | __add_wait_queue(q, &wait); | |
3686 | spin_unlock(&q->lock); | |
3687 | timeout = schedule_timeout(timeout); | |
3688 | spin_lock_irq(&q->lock); | |
3689 | __remove_wait_queue(q, &wait); | |
3690 | spin_unlock_irqrestore(&q->lock, flags); | |
3691 | ||
3692 | return timeout; | |
3693 | } | |
3694 | ||
3695 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
3696 | { | |
3697 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 3698 | } |
1da177e4 LT |
3699 | EXPORT_SYMBOL(interruptible_sleep_on); |
3700 | ||
0fec171c | 3701 | long __sched |
95cdf3b7 | 3702 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 3703 | { |
8cbbe86d | 3704 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 3705 | } |
1da177e4 LT |
3706 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
3707 | ||
0fec171c | 3708 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 3709 | { |
8cbbe86d | 3710 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 3711 | } |
1da177e4 LT |
3712 | EXPORT_SYMBOL(sleep_on); |
3713 | ||
0fec171c | 3714 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 3715 | { |
8cbbe86d | 3716 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 3717 | } |
1da177e4 LT |
3718 | EXPORT_SYMBOL(sleep_on_timeout); |
3719 | ||
b29739f9 IM |
3720 | #ifdef CONFIG_RT_MUTEXES |
3721 | ||
3722 | /* | |
3723 | * rt_mutex_setprio - set the current priority of a task | |
3724 | * @p: task | |
3725 | * @prio: prio value (kernel-internal form) | |
3726 | * | |
3727 | * This function changes the 'effective' priority of a task. It does | |
3728 | * not touch ->normal_prio like __setscheduler(). | |
3729 | * | |
3730 | * Used by the rt_mutex code to implement priority inheritance logic. | |
3731 | */ | |
36c8b586 | 3732 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 3733 | { |
83b699ed | 3734 | int oldprio, on_rq, running; |
70b97a7f | 3735 | struct rq *rq; |
83ab0aa0 | 3736 | const struct sched_class *prev_class; |
b29739f9 IM |
3737 | |
3738 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
3739 | ||
0122ec5b | 3740 | rq = __task_rq_lock(p); |
b29739f9 | 3741 | |
a8027073 | 3742 | trace_sched_pi_setprio(p, prio); |
d5f9f942 | 3743 | oldprio = p->prio; |
83ab0aa0 | 3744 | prev_class = p->sched_class; |
fd2f4419 | 3745 | on_rq = p->on_rq; |
051a1d1a | 3746 | running = task_current(rq, p); |
0e1f3483 | 3747 | if (on_rq) |
69be72c1 | 3748 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
3749 | if (running) |
3750 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
3751 | |
3752 | if (rt_prio(prio)) | |
3753 | p->sched_class = &rt_sched_class; | |
3754 | else | |
3755 | p->sched_class = &fair_sched_class; | |
3756 | ||
b29739f9 IM |
3757 | p->prio = prio; |
3758 | ||
0e1f3483 HS |
3759 | if (running) |
3760 | p->sched_class->set_curr_task(rq); | |
da7a735e | 3761 | if (on_rq) |
371fd7e7 | 3762 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 | 3763 | |
da7a735e | 3764 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 3765 | __task_rq_unlock(rq); |
b29739f9 IM |
3766 | } |
3767 | ||
3768 | #endif | |
3769 | ||
36c8b586 | 3770 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 3771 | { |
dd41f596 | 3772 | int old_prio, delta, on_rq; |
1da177e4 | 3773 | unsigned long flags; |
70b97a7f | 3774 | struct rq *rq; |
1da177e4 LT |
3775 | |
3776 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
3777 | return; | |
3778 | /* | |
3779 | * We have to be careful, if called from sys_setpriority(), | |
3780 | * the task might be in the middle of scheduling on another CPU. | |
3781 | */ | |
3782 | rq = task_rq_lock(p, &flags); | |
3783 | /* | |
3784 | * The RT priorities are set via sched_setscheduler(), but we still | |
3785 | * allow the 'normal' nice value to be set - but as expected | |
3786 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 3787 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 3788 | */ |
e05606d3 | 3789 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
3790 | p->static_prio = NICE_TO_PRIO(nice); |
3791 | goto out_unlock; | |
3792 | } | |
fd2f4419 | 3793 | on_rq = p->on_rq; |
c09595f6 | 3794 | if (on_rq) |
69be72c1 | 3795 | dequeue_task(rq, p, 0); |
1da177e4 | 3796 | |
1da177e4 | 3797 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 3798 | set_load_weight(p); |
b29739f9 IM |
3799 | old_prio = p->prio; |
3800 | p->prio = effective_prio(p); | |
3801 | delta = p->prio - old_prio; | |
1da177e4 | 3802 | |
dd41f596 | 3803 | if (on_rq) { |
371fd7e7 | 3804 | enqueue_task(rq, p, 0); |
1da177e4 | 3805 | /* |
d5f9f942 AM |
3806 | * If the task increased its priority or is running and |
3807 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 3808 | */ |
d5f9f942 | 3809 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
3810 | resched_task(rq->curr); |
3811 | } | |
3812 | out_unlock: | |
0122ec5b | 3813 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 3814 | } |
1da177e4 LT |
3815 | EXPORT_SYMBOL(set_user_nice); |
3816 | ||
e43379f1 MM |
3817 | /* |
3818 | * can_nice - check if a task can reduce its nice value | |
3819 | * @p: task | |
3820 | * @nice: nice value | |
3821 | */ | |
36c8b586 | 3822 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 3823 | { |
024f4747 MM |
3824 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
3825 | int nice_rlim = 20 - nice; | |
48f24c4d | 3826 | |
78d7d407 | 3827 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
3828 | capable(CAP_SYS_NICE)); |
3829 | } | |
3830 | ||
1da177e4 LT |
3831 | #ifdef __ARCH_WANT_SYS_NICE |
3832 | ||
3833 | /* | |
3834 | * sys_nice - change the priority of the current process. | |
3835 | * @increment: priority increment | |
3836 | * | |
3837 | * sys_setpriority is a more generic, but much slower function that | |
3838 | * does similar things. | |
3839 | */ | |
5add95d4 | 3840 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 3841 | { |
48f24c4d | 3842 | long nice, retval; |
1da177e4 LT |
3843 | |
3844 | /* | |
3845 | * Setpriority might change our priority at the same moment. | |
3846 | * We don't have to worry. Conceptually one call occurs first | |
3847 | * and we have a single winner. | |
3848 | */ | |
e43379f1 MM |
3849 | if (increment < -40) |
3850 | increment = -40; | |
1da177e4 LT |
3851 | if (increment > 40) |
3852 | increment = 40; | |
3853 | ||
2b8f836f | 3854 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
3855 | if (nice < -20) |
3856 | nice = -20; | |
3857 | if (nice > 19) | |
3858 | nice = 19; | |
3859 | ||
e43379f1 MM |
3860 | if (increment < 0 && !can_nice(current, nice)) |
3861 | return -EPERM; | |
3862 | ||
1da177e4 LT |
3863 | retval = security_task_setnice(current, nice); |
3864 | if (retval) | |
3865 | return retval; | |
3866 | ||
3867 | set_user_nice(current, nice); | |
3868 | return 0; | |
3869 | } | |
3870 | ||
3871 | #endif | |
3872 | ||
3873 | /** | |
3874 | * task_prio - return the priority value of a given task. | |
3875 | * @p: the task in question. | |
3876 | * | |
3877 | * This is the priority value as seen by users in /proc. | |
3878 | * RT tasks are offset by -200. Normal tasks are centered | |
3879 | * around 0, value goes from -16 to +15. | |
3880 | */ | |
36c8b586 | 3881 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
3882 | { |
3883 | return p->prio - MAX_RT_PRIO; | |
3884 | } | |
3885 | ||
3886 | /** | |
3887 | * task_nice - return the nice value of a given task. | |
3888 | * @p: the task in question. | |
3889 | */ | |
36c8b586 | 3890 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
3891 | { |
3892 | return TASK_NICE(p); | |
3893 | } | |
150d8bed | 3894 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
3895 | |
3896 | /** | |
3897 | * idle_cpu - is a given cpu idle currently? | |
3898 | * @cpu: the processor in question. | |
3899 | */ | |
3900 | int idle_cpu(int cpu) | |
3901 | { | |
908a3283 TG |
3902 | struct rq *rq = cpu_rq(cpu); |
3903 | ||
3904 | if (rq->curr != rq->idle) | |
3905 | return 0; | |
3906 | ||
3907 | if (rq->nr_running) | |
3908 | return 0; | |
3909 | ||
3910 | #ifdef CONFIG_SMP | |
3911 | if (!llist_empty(&rq->wake_list)) | |
3912 | return 0; | |
3913 | #endif | |
3914 | ||
3915 | return 1; | |
1da177e4 LT |
3916 | } |
3917 | ||
1da177e4 LT |
3918 | /** |
3919 | * idle_task - return the idle task for a given cpu. | |
3920 | * @cpu: the processor in question. | |
3921 | */ | |
36c8b586 | 3922 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
3923 | { |
3924 | return cpu_rq(cpu)->idle; | |
3925 | } | |
3926 | ||
3927 | /** | |
3928 | * find_process_by_pid - find a process with a matching PID value. | |
3929 | * @pid: the pid in question. | |
3930 | */ | |
a9957449 | 3931 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 3932 | { |
228ebcbe | 3933 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
3934 | } |
3935 | ||
3936 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
3937 | static void |
3938 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 3939 | { |
1da177e4 LT |
3940 | p->policy = policy; |
3941 | p->rt_priority = prio; | |
b29739f9 IM |
3942 | p->normal_prio = normal_prio(p); |
3943 | /* we are holding p->pi_lock already */ | |
3944 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
3945 | if (rt_prio(p->prio)) |
3946 | p->sched_class = &rt_sched_class; | |
3947 | else | |
3948 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 3949 | set_load_weight(p); |
1da177e4 LT |
3950 | } |
3951 | ||
c69e8d9c DH |
3952 | /* |
3953 | * check the target process has a UID that matches the current process's | |
3954 | */ | |
3955 | static bool check_same_owner(struct task_struct *p) | |
3956 | { | |
3957 | const struct cred *cred = current_cred(), *pcred; | |
3958 | bool match; | |
3959 | ||
3960 | rcu_read_lock(); | |
3961 | pcred = __task_cred(p); | |
b0e77598 SH |
3962 | if (cred->user->user_ns == pcred->user->user_ns) |
3963 | match = (cred->euid == pcred->euid || | |
3964 | cred->euid == pcred->uid); | |
3965 | else | |
3966 | match = false; | |
c69e8d9c DH |
3967 | rcu_read_unlock(); |
3968 | return match; | |
3969 | } | |
3970 | ||
961ccddd | 3971 | static int __sched_setscheduler(struct task_struct *p, int policy, |
fe7de49f | 3972 | const struct sched_param *param, bool user) |
1da177e4 | 3973 | { |
83b699ed | 3974 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 3975 | unsigned long flags; |
83ab0aa0 | 3976 | const struct sched_class *prev_class; |
70b97a7f | 3977 | struct rq *rq; |
ca94c442 | 3978 | int reset_on_fork; |
1da177e4 | 3979 | |
66e5393a SR |
3980 | /* may grab non-irq protected spin_locks */ |
3981 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
3982 | recheck: |
3983 | /* double check policy once rq lock held */ | |
ca94c442 LP |
3984 | if (policy < 0) { |
3985 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 3986 | policy = oldpolicy = p->policy; |
ca94c442 LP |
3987 | } else { |
3988 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
3989 | policy &= ~SCHED_RESET_ON_FORK; | |
3990 | ||
3991 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
3992 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
3993 | policy != SCHED_IDLE) | |
3994 | return -EINVAL; | |
3995 | } | |
3996 | ||
1da177e4 LT |
3997 | /* |
3998 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
3999 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
4000 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
4001 | */ |
4002 | if (param->sched_priority < 0 || | |
95cdf3b7 | 4003 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 4004 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 4005 | return -EINVAL; |
e05606d3 | 4006 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
4007 | return -EINVAL; |
4008 | ||
37e4ab3f OC |
4009 | /* |
4010 | * Allow unprivileged RT tasks to decrease priority: | |
4011 | */ | |
961ccddd | 4012 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 4013 | if (rt_policy(policy)) { |
a44702e8 ON |
4014 | unsigned long rlim_rtprio = |
4015 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
4016 | |
4017 | /* can't set/change the rt policy */ | |
4018 | if (policy != p->policy && !rlim_rtprio) | |
4019 | return -EPERM; | |
4020 | ||
4021 | /* can't increase priority */ | |
4022 | if (param->sched_priority > p->rt_priority && | |
4023 | param->sched_priority > rlim_rtprio) | |
4024 | return -EPERM; | |
4025 | } | |
c02aa73b | 4026 | |
dd41f596 | 4027 | /* |
c02aa73b DH |
4028 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
4029 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 4030 | */ |
c02aa73b DH |
4031 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
4032 | if (!can_nice(p, TASK_NICE(p))) | |
4033 | return -EPERM; | |
4034 | } | |
5fe1d75f | 4035 | |
37e4ab3f | 4036 | /* can't change other user's priorities */ |
c69e8d9c | 4037 | if (!check_same_owner(p)) |
37e4ab3f | 4038 | return -EPERM; |
ca94c442 LP |
4039 | |
4040 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
4041 | if (p->sched_reset_on_fork && !reset_on_fork) | |
4042 | return -EPERM; | |
37e4ab3f | 4043 | } |
1da177e4 | 4044 | |
725aad24 | 4045 | if (user) { |
b0ae1981 | 4046 | retval = security_task_setscheduler(p); |
725aad24 JF |
4047 | if (retval) |
4048 | return retval; | |
4049 | } | |
4050 | ||
b29739f9 IM |
4051 | /* |
4052 | * make sure no PI-waiters arrive (or leave) while we are | |
4053 | * changing the priority of the task: | |
0122ec5b | 4054 | * |
25985edc | 4055 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
4056 | * runqueue lock must be held. |
4057 | */ | |
0122ec5b | 4058 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 4059 | |
34f971f6 PZ |
4060 | /* |
4061 | * Changing the policy of the stop threads its a very bad idea | |
4062 | */ | |
4063 | if (p == rq->stop) { | |
0122ec5b | 4064 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
4065 | return -EINVAL; |
4066 | } | |
4067 | ||
a51e9198 DF |
4068 | /* |
4069 | * If not changing anything there's no need to proceed further: | |
4070 | */ | |
4071 | if (unlikely(policy == p->policy && (!rt_policy(policy) || | |
4072 | param->sched_priority == p->rt_priority))) { | |
4073 | ||
4074 | __task_rq_unlock(rq); | |
4075 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); | |
4076 | return 0; | |
4077 | } | |
4078 | ||
dc61b1d6 PZ |
4079 | #ifdef CONFIG_RT_GROUP_SCHED |
4080 | if (user) { | |
4081 | /* | |
4082 | * Do not allow realtime tasks into groups that have no runtime | |
4083 | * assigned. | |
4084 | */ | |
4085 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
4086 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
4087 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 4088 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
4089 | return -EPERM; |
4090 | } | |
4091 | } | |
4092 | #endif | |
4093 | ||
1da177e4 LT |
4094 | /* recheck policy now with rq lock held */ |
4095 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
4096 | policy = oldpolicy = -1; | |
0122ec5b | 4097 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
4098 | goto recheck; |
4099 | } | |
fd2f4419 | 4100 | on_rq = p->on_rq; |
051a1d1a | 4101 | running = task_current(rq, p); |
0e1f3483 | 4102 | if (on_rq) |
2e1cb74a | 4103 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
4104 | if (running) |
4105 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 4106 | |
ca94c442 LP |
4107 | p->sched_reset_on_fork = reset_on_fork; |
4108 | ||
1da177e4 | 4109 | oldprio = p->prio; |
83ab0aa0 | 4110 | prev_class = p->sched_class; |
dd41f596 | 4111 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 4112 | |
0e1f3483 HS |
4113 | if (running) |
4114 | p->sched_class->set_curr_task(rq); | |
da7a735e | 4115 | if (on_rq) |
dd41f596 | 4116 | activate_task(rq, p, 0); |
cb469845 | 4117 | |
da7a735e | 4118 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 4119 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 4120 | |
95e02ca9 TG |
4121 | rt_mutex_adjust_pi(p); |
4122 | ||
1da177e4 LT |
4123 | return 0; |
4124 | } | |
961ccddd RR |
4125 | |
4126 | /** | |
4127 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
4128 | * @p: the task in question. | |
4129 | * @policy: new policy. | |
4130 | * @param: structure containing the new RT priority. | |
4131 | * | |
4132 | * NOTE that the task may be already dead. | |
4133 | */ | |
4134 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 4135 | const struct sched_param *param) |
961ccddd RR |
4136 | { |
4137 | return __sched_setscheduler(p, policy, param, true); | |
4138 | } | |
1da177e4 LT |
4139 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
4140 | ||
961ccddd RR |
4141 | /** |
4142 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
4143 | * @p: the task in question. | |
4144 | * @policy: new policy. | |
4145 | * @param: structure containing the new RT priority. | |
4146 | * | |
4147 | * Just like sched_setscheduler, only don't bother checking if the | |
4148 | * current context has permission. For example, this is needed in | |
4149 | * stop_machine(): we create temporary high priority worker threads, | |
4150 | * but our caller might not have that capability. | |
4151 | */ | |
4152 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 4153 | const struct sched_param *param) |
961ccddd RR |
4154 | { |
4155 | return __sched_setscheduler(p, policy, param, false); | |
4156 | } | |
4157 | ||
95cdf3b7 IM |
4158 | static int |
4159 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 4160 | { |
1da177e4 LT |
4161 | struct sched_param lparam; |
4162 | struct task_struct *p; | |
36c8b586 | 4163 | int retval; |
1da177e4 LT |
4164 | |
4165 | if (!param || pid < 0) | |
4166 | return -EINVAL; | |
4167 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
4168 | return -EFAULT; | |
5fe1d75f ON |
4169 | |
4170 | rcu_read_lock(); | |
4171 | retval = -ESRCH; | |
1da177e4 | 4172 | p = find_process_by_pid(pid); |
5fe1d75f ON |
4173 | if (p != NULL) |
4174 | retval = sched_setscheduler(p, policy, &lparam); | |
4175 | rcu_read_unlock(); | |
36c8b586 | 4176 | |
1da177e4 LT |
4177 | return retval; |
4178 | } | |
4179 | ||
4180 | /** | |
4181 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
4182 | * @pid: the pid in question. | |
4183 | * @policy: new policy. | |
4184 | * @param: structure containing the new RT priority. | |
4185 | */ | |
5add95d4 HC |
4186 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
4187 | struct sched_param __user *, param) | |
1da177e4 | 4188 | { |
c21761f1 JB |
4189 | /* negative values for policy are not valid */ |
4190 | if (policy < 0) | |
4191 | return -EINVAL; | |
4192 | ||
1da177e4 LT |
4193 | return do_sched_setscheduler(pid, policy, param); |
4194 | } | |
4195 | ||
4196 | /** | |
4197 | * sys_sched_setparam - set/change the RT priority of a thread | |
4198 | * @pid: the pid in question. | |
4199 | * @param: structure containing the new RT priority. | |
4200 | */ | |
5add95d4 | 4201 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4202 | { |
4203 | return do_sched_setscheduler(pid, -1, param); | |
4204 | } | |
4205 | ||
4206 | /** | |
4207 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
4208 | * @pid: the pid in question. | |
4209 | */ | |
5add95d4 | 4210 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 4211 | { |
36c8b586 | 4212 | struct task_struct *p; |
3a5c359a | 4213 | int retval; |
1da177e4 LT |
4214 | |
4215 | if (pid < 0) | |
3a5c359a | 4216 | return -EINVAL; |
1da177e4 LT |
4217 | |
4218 | retval = -ESRCH; | |
5fe85be0 | 4219 | rcu_read_lock(); |
1da177e4 LT |
4220 | p = find_process_by_pid(pid); |
4221 | if (p) { | |
4222 | retval = security_task_getscheduler(p); | |
4223 | if (!retval) | |
ca94c442 LP |
4224 | retval = p->policy |
4225 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 4226 | } |
5fe85be0 | 4227 | rcu_read_unlock(); |
1da177e4 LT |
4228 | return retval; |
4229 | } | |
4230 | ||
4231 | /** | |
ca94c442 | 4232 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
4233 | * @pid: the pid in question. |
4234 | * @param: structure containing the RT priority. | |
4235 | */ | |
5add95d4 | 4236 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4237 | { |
4238 | struct sched_param lp; | |
36c8b586 | 4239 | struct task_struct *p; |
3a5c359a | 4240 | int retval; |
1da177e4 LT |
4241 | |
4242 | if (!param || pid < 0) | |
3a5c359a | 4243 | return -EINVAL; |
1da177e4 | 4244 | |
5fe85be0 | 4245 | rcu_read_lock(); |
1da177e4 LT |
4246 | p = find_process_by_pid(pid); |
4247 | retval = -ESRCH; | |
4248 | if (!p) | |
4249 | goto out_unlock; | |
4250 | ||
4251 | retval = security_task_getscheduler(p); | |
4252 | if (retval) | |
4253 | goto out_unlock; | |
4254 | ||
4255 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 4256 | rcu_read_unlock(); |
1da177e4 LT |
4257 | |
4258 | /* | |
4259 | * This one might sleep, we cannot do it with a spinlock held ... | |
4260 | */ | |
4261 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
4262 | ||
1da177e4 LT |
4263 | return retval; |
4264 | ||
4265 | out_unlock: | |
5fe85be0 | 4266 | rcu_read_unlock(); |
1da177e4 LT |
4267 | return retval; |
4268 | } | |
4269 | ||
96f874e2 | 4270 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4271 | { |
5a16f3d3 | 4272 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4273 | struct task_struct *p; |
4274 | int retval; | |
1da177e4 | 4275 | |
95402b38 | 4276 | get_online_cpus(); |
23f5d142 | 4277 | rcu_read_lock(); |
1da177e4 LT |
4278 | |
4279 | p = find_process_by_pid(pid); | |
4280 | if (!p) { | |
23f5d142 | 4281 | rcu_read_unlock(); |
95402b38 | 4282 | put_online_cpus(); |
1da177e4 LT |
4283 | return -ESRCH; |
4284 | } | |
4285 | ||
23f5d142 | 4286 | /* Prevent p going away */ |
1da177e4 | 4287 | get_task_struct(p); |
23f5d142 | 4288 | rcu_read_unlock(); |
1da177e4 | 4289 | |
5a16f3d3 RR |
4290 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4291 | retval = -ENOMEM; | |
4292 | goto out_put_task; | |
4293 | } | |
4294 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4295 | retval = -ENOMEM; | |
4296 | goto out_free_cpus_allowed; | |
4297 | } | |
1da177e4 | 4298 | retval = -EPERM; |
b0e77598 | 4299 | if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE)) |
1da177e4 LT |
4300 | goto out_unlock; |
4301 | ||
b0ae1981 | 4302 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
4303 | if (retval) |
4304 | goto out_unlock; | |
4305 | ||
5a16f3d3 RR |
4306 | cpuset_cpus_allowed(p, cpus_allowed); |
4307 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
49246274 | 4308 | again: |
5a16f3d3 | 4309 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4310 | |
8707d8b8 | 4311 | if (!retval) { |
5a16f3d3 RR |
4312 | cpuset_cpus_allowed(p, cpus_allowed); |
4313 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4314 | /* |
4315 | * We must have raced with a concurrent cpuset | |
4316 | * update. Just reset the cpus_allowed to the | |
4317 | * cpuset's cpus_allowed | |
4318 | */ | |
5a16f3d3 | 4319 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4320 | goto again; |
4321 | } | |
4322 | } | |
1da177e4 | 4323 | out_unlock: |
5a16f3d3 RR |
4324 | free_cpumask_var(new_mask); |
4325 | out_free_cpus_allowed: | |
4326 | free_cpumask_var(cpus_allowed); | |
4327 | out_put_task: | |
1da177e4 | 4328 | put_task_struct(p); |
95402b38 | 4329 | put_online_cpus(); |
1da177e4 LT |
4330 | return retval; |
4331 | } | |
4332 | ||
4333 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4334 | struct cpumask *new_mask) |
1da177e4 | 4335 | { |
96f874e2 RR |
4336 | if (len < cpumask_size()) |
4337 | cpumask_clear(new_mask); | |
4338 | else if (len > cpumask_size()) | |
4339 | len = cpumask_size(); | |
4340 | ||
1da177e4 LT |
4341 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4342 | } | |
4343 | ||
4344 | /** | |
4345 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4346 | * @pid: pid of the process | |
4347 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4348 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
4349 | */ | |
5add95d4 HC |
4350 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4351 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4352 | { |
5a16f3d3 | 4353 | cpumask_var_t new_mask; |
1da177e4 LT |
4354 | int retval; |
4355 | ||
5a16f3d3 RR |
4356 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4357 | return -ENOMEM; | |
1da177e4 | 4358 | |
5a16f3d3 RR |
4359 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4360 | if (retval == 0) | |
4361 | retval = sched_setaffinity(pid, new_mask); | |
4362 | free_cpumask_var(new_mask); | |
4363 | return retval; | |
1da177e4 LT |
4364 | } |
4365 | ||
96f874e2 | 4366 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4367 | { |
36c8b586 | 4368 | struct task_struct *p; |
31605683 | 4369 | unsigned long flags; |
1da177e4 | 4370 | int retval; |
1da177e4 | 4371 | |
95402b38 | 4372 | get_online_cpus(); |
23f5d142 | 4373 | rcu_read_lock(); |
1da177e4 LT |
4374 | |
4375 | retval = -ESRCH; | |
4376 | p = find_process_by_pid(pid); | |
4377 | if (!p) | |
4378 | goto out_unlock; | |
4379 | ||
e7834f8f DQ |
4380 | retval = security_task_getscheduler(p); |
4381 | if (retval) | |
4382 | goto out_unlock; | |
4383 | ||
013fdb80 | 4384 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
96f874e2 | 4385 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
013fdb80 | 4386 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4387 | |
4388 | out_unlock: | |
23f5d142 | 4389 | rcu_read_unlock(); |
95402b38 | 4390 | put_online_cpus(); |
1da177e4 | 4391 | |
9531b62f | 4392 | return retval; |
1da177e4 LT |
4393 | } |
4394 | ||
4395 | /** | |
4396 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4397 | * @pid: pid of the process | |
4398 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4399 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
4400 | */ | |
5add95d4 HC |
4401 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4402 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4403 | { |
4404 | int ret; | |
f17c8607 | 4405 | cpumask_var_t mask; |
1da177e4 | 4406 | |
84fba5ec | 4407 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4408 | return -EINVAL; |
4409 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4410 | return -EINVAL; |
4411 | ||
f17c8607 RR |
4412 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4413 | return -ENOMEM; | |
1da177e4 | 4414 | |
f17c8607 RR |
4415 | ret = sched_getaffinity(pid, mask); |
4416 | if (ret == 0) { | |
8bc037fb | 4417 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4418 | |
4419 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4420 | ret = -EFAULT; |
4421 | else | |
cd3d8031 | 4422 | ret = retlen; |
f17c8607 RR |
4423 | } |
4424 | free_cpumask_var(mask); | |
1da177e4 | 4425 | |
f17c8607 | 4426 | return ret; |
1da177e4 LT |
4427 | } |
4428 | ||
4429 | /** | |
4430 | * sys_sched_yield - yield the current processor to other threads. | |
4431 | * | |
dd41f596 IM |
4432 | * This function yields the current CPU to other tasks. If there are no |
4433 | * other threads running on this CPU then this function will return. | |
1da177e4 | 4434 | */ |
5add95d4 | 4435 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4436 | { |
70b97a7f | 4437 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4438 | |
2d72376b | 4439 | schedstat_inc(rq, yld_count); |
4530d7ab | 4440 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4441 | |
4442 | /* | |
4443 | * Since we are going to call schedule() anyway, there's | |
4444 | * no need to preempt or enable interrupts: | |
4445 | */ | |
4446 | __release(rq->lock); | |
8a25d5de | 4447 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4448 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
4449 | preempt_enable_no_resched(); |
4450 | ||
4451 | schedule(); | |
4452 | ||
4453 | return 0; | |
4454 | } | |
4455 | ||
d86ee480 PZ |
4456 | static inline int should_resched(void) |
4457 | { | |
4458 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
4459 | } | |
4460 | ||
e7b38404 | 4461 | static void __cond_resched(void) |
1da177e4 | 4462 | { |
e7aaaa69 | 4463 | add_preempt_count(PREEMPT_ACTIVE); |
c259e01a | 4464 | __schedule(); |
e7aaaa69 | 4465 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 LT |
4466 | } |
4467 | ||
02b67cc3 | 4468 | int __sched _cond_resched(void) |
1da177e4 | 4469 | { |
d86ee480 | 4470 | if (should_resched()) { |
1da177e4 LT |
4471 | __cond_resched(); |
4472 | return 1; | |
4473 | } | |
4474 | return 0; | |
4475 | } | |
02b67cc3 | 4476 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4477 | |
4478 | /* | |
613afbf8 | 4479 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4480 | * call schedule, and on return reacquire the lock. |
4481 | * | |
41a2d6cf | 4482 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4483 | * operations here to prevent schedule() from being called twice (once via |
4484 | * spin_unlock(), once by hand). | |
4485 | */ | |
613afbf8 | 4486 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4487 | { |
d86ee480 | 4488 | int resched = should_resched(); |
6df3cecb JK |
4489 | int ret = 0; |
4490 | ||
f607c668 PZ |
4491 | lockdep_assert_held(lock); |
4492 | ||
95c354fe | 4493 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 4494 | spin_unlock(lock); |
d86ee480 | 4495 | if (resched) |
95c354fe NP |
4496 | __cond_resched(); |
4497 | else | |
4498 | cpu_relax(); | |
6df3cecb | 4499 | ret = 1; |
1da177e4 | 4500 | spin_lock(lock); |
1da177e4 | 4501 | } |
6df3cecb | 4502 | return ret; |
1da177e4 | 4503 | } |
613afbf8 | 4504 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4505 | |
613afbf8 | 4506 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4507 | { |
4508 | BUG_ON(!in_softirq()); | |
4509 | ||
d86ee480 | 4510 | if (should_resched()) { |
98d82567 | 4511 | local_bh_enable(); |
1da177e4 LT |
4512 | __cond_resched(); |
4513 | local_bh_disable(); | |
4514 | return 1; | |
4515 | } | |
4516 | return 0; | |
4517 | } | |
613afbf8 | 4518 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4519 | |
1da177e4 LT |
4520 | /** |
4521 | * yield - yield the current processor to other threads. | |
4522 | * | |
72fd4a35 | 4523 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
4524 | * thread runnable and calls sys_sched_yield(). |
4525 | */ | |
4526 | void __sched yield(void) | |
4527 | { | |
4528 | set_current_state(TASK_RUNNING); | |
4529 | sys_sched_yield(); | |
4530 | } | |
1da177e4 LT |
4531 | EXPORT_SYMBOL(yield); |
4532 | ||
d95f4122 MG |
4533 | /** |
4534 | * yield_to - yield the current processor to another thread in | |
4535 | * your thread group, or accelerate that thread toward the | |
4536 | * processor it's on. | |
16addf95 RD |
4537 | * @p: target task |
4538 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
4539 | * |
4540 | * It's the caller's job to ensure that the target task struct | |
4541 | * can't go away on us before we can do any checks. | |
4542 | * | |
4543 | * Returns true if we indeed boosted the target task. | |
4544 | */ | |
4545 | bool __sched yield_to(struct task_struct *p, bool preempt) | |
4546 | { | |
4547 | struct task_struct *curr = current; | |
4548 | struct rq *rq, *p_rq; | |
4549 | unsigned long flags; | |
4550 | bool yielded = 0; | |
4551 | ||
4552 | local_irq_save(flags); | |
4553 | rq = this_rq(); | |
4554 | ||
4555 | again: | |
4556 | p_rq = task_rq(p); | |
4557 | double_rq_lock(rq, p_rq); | |
4558 | while (task_rq(p) != p_rq) { | |
4559 | double_rq_unlock(rq, p_rq); | |
4560 | goto again; | |
4561 | } | |
4562 | ||
4563 | if (!curr->sched_class->yield_to_task) | |
4564 | goto out; | |
4565 | ||
4566 | if (curr->sched_class != p->sched_class) | |
4567 | goto out; | |
4568 | ||
4569 | if (task_running(p_rq, p) || p->state) | |
4570 | goto out; | |
4571 | ||
4572 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 4573 | if (yielded) { |
d95f4122 | 4574 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
4575 | /* |
4576 | * Make p's CPU reschedule; pick_next_entity takes care of | |
4577 | * fairness. | |
4578 | */ | |
4579 | if (preempt && rq != p_rq) | |
4580 | resched_task(p_rq->curr); | |
916671c0 MG |
4581 | } else { |
4582 | /* | |
4583 | * We might have set it in task_yield_fair(), but are | |
4584 | * not going to schedule(), so don't want to skip | |
4585 | * the next update. | |
4586 | */ | |
4587 | rq->skip_clock_update = 0; | |
6d1cafd8 | 4588 | } |
d95f4122 MG |
4589 | |
4590 | out: | |
4591 | double_rq_unlock(rq, p_rq); | |
4592 | local_irq_restore(flags); | |
4593 | ||
4594 | if (yielded) | |
4595 | schedule(); | |
4596 | ||
4597 | return yielded; | |
4598 | } | |
4599 | EXPORT_SYMBOL_GPL(yield_to); | |
4600 | ||
1da177e4 | 4601 | /* |
41a2d6cf | 4602 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4603 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4604 | */ |
4605 | void __sched io_schedule(void) | |
4606 | { | |
54d35f29 | 4607 | struct rq *rq = raw_rq(); |
1da177e4 | 4608 | |
0ff92245 | 4609 | delayacct_blkio_start(); |
1da177e4 | 4610 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4611 | blk_flush_plug(current); |
8f0dfc34 | 4612 | current->in_iowait = 1; |
1da177e4 | 4613 | schedule(); |
8f0dfc34 | 4614 | current->in_iowait = 0; |
1da177e4 | 4615 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4616 | delayacct_blkio_end(); |
1da177e4 | 4617 | } |
1da177e4 LT |
4618 | EXPORT_SYMBOL(io_schedule); |
4619 | ||
4620 | long __sched io_schedule_timeout(long timeout) | |
4621 | { | |
54d35f29 | 4622 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4623 | long ret; |
4624 | ||
0ff92245 | 4625 | delayacct_blkio_start(); |
1da177e4 | 4626 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4627 | blk_flush_plug(current); |
8f0dfc34 | 4628 | current->in_iowait = 1; |
1da177e4 | 4629 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4630 | current->in_iowait = 0; |
1da177e4 | 4631 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4632 | delayacct_blkio_end(); |
1da177e4 LT |
4633 | return ret; |
4634 | } | |
4635 | ||
4636 | /** | |
4637 | * sys_sched_get_priority_max - return maximum RT priority. | |
4638 | * @policy: scheduling class. | |
4639 | * | |
4640 | * this syscall returns the maximum rt_priority that can be used | |
4641 | * by a given scheduling class. | |
4642 | */ | |
5add95d4 | 4643 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4644 | { |
4645 | int ret = -EINVAL; | |
4646 | ||
4647 | switch (policy) { | |
4648 | case SCHED_FIFO: | |
4649 | case SCHED_RR: | |
4650 | ret = MAX_USER_RT_PRIO-1; | |
4651 | break; | |
4652 | case SCHED_NORMAL: | |
b0a9499c | 4653 | case SCHED_BATCH: |
dd41f596 | 4654 | case SCHED_IDLE: |
1da177e4 LT |
4655 | ret = 0; |
4656 | break; | |
4657 | } | |
4658 | return ret; | |
4659 | } | |
4660 | ||
4661 | /** | |
4662 | * sys_sched_get_priority_min - return minimum RT priority. | |
4663 | * @policy: scheduling class. | |
4664 | * | |
4665 | * this syscall returns the minimum rt_priority that can be used | |
4666 | * by a given scheduling class. | |
4667 | */ | |
5add95d4 | 4668 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
4669 | { |
4670 | int ret = -EINVAL; | |
4671 | ||
4672 | switch (policy) { | |
4673 | case SCHED_FIFO: | |
4674 | case SCHED_RR: | |
4675 | ret = 1; | |
4676 | break; | |
4677 | case SCHED_NORMAL: | |
b0a9499c | 4678 | case SCHED_BATCH: |
dd41f596 | 4679 | case SCHED_IDLE: |
1da177e4 LT |
4680 | ret = 0; |
4681 | } | |
4682 | return ret; | |
4683 | } | |
4684 | ||
4685 | /** | |
4686 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
4687 | * @pid: pid of the process. | |
4688 | * @interval: userspace pointer to the timeslice value. | |
4689 | * | |
4690 | * this syscall writes the default timeslice value of a given process | |
4691 | * into the user-space timespec buffer. A value of '0' means infinity. | |
4692 | */ | |
17da2bd9 | 4693 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 4694 | struct timespec __user *, interval) |
1da177e4 | 4695 | { |
36c8b586 | 4696 | struct task_struct *p; |
a4ec24b4 | 4697 | unsigned int time_slice; |
dba091b9 TG |
4698 | unsigned long flags; |
4699 | struct rq *rq; | |
3a5c359a | 4700 | int retval; |
1da177e4 | 4701 | struct timespec t; |
1da177e4 LT |
4702 | |
4703 | if (pid < 0) | |
3a5c359a | 4704 | return -EINVAL; |
1da177e4 LT |
4705 | |
4706 | retval = -ESRCH; | |
1a551ae7 | 4707 | rcu_read_lock(); |
1da177e4 LT |
4708 | p = find_process_by_pid(pid); |
4709 | if (!p) | |
4710 | goto out_unlock; | |
4711 | ||
4712 | retval = security_task_getscheduler(p); | |
4713 | if (retval) | |
4714 | goto out_unlock; | |
4715 | ||
dba091b9 TG |
4716 | rq = task_rq_lock(p, &flags); |
4717 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 4718 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 4719 | |
1a551ae7 | 4720 | rcu_read_unlock(); |
a4ec24b4 | 4721 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 4722 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 4723 | return retval; |
3a5c359a | 4724 | |
1da177e4 | 4725 | out_unlock: |
1a551ae7 | 4726 | rcu_read_unlock(); |
1da177e4 LT |
4727 | return retval; |
4728 | } | |
4729 | ||
7c731e0a | 4730 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 4731 | |
82a1fcb9 | 4732 | void sched_show_task(struct task_struct *p) |
1da177e4 | 4733 | { |
1da177e4 | 4734 | unsigned long free = 0; |
36c8b586 | 4735 | unsigned state; |
1da177e4 | 4736 | |
1da177e4 | 4737 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 4738 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 4739 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 4740 | #if BITS_PER_LONG == 32 |
1da177e4 | 4741 | if (state == TASK_RUNNING) |
3df0fc5b | 4742 | printk(KERN_CONT " running "); |
1da177e4 | 4743 | else |
3df0fc5b | 4744 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
4745 | #else |
4746 | if (state == TASK_RUNNING) | |
3df0fc5b | 4747 | printk(KERN_CONT " running task "); |
1da177e4 | 4748 | else |
3df0fc5b | 4749 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
4750 | #endif |
4751 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 4752 | free = stack_not_used(p); |
1da177e4 | 4753 | #endif |
3df0fc5b | 4754 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
4755 | task_pid_nr(p), task_pid_nr(p->real_parent), |
4756 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 4757 | |
5fb5e6de | 4758 | show_stack(p, NULL); |
1da177e4 LT |
4759 | } |
4760 | ||
e59e2ae2 | 4761 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 4762 | { |
36c8b586 | 4763 | struct task_struct *g, *p; |
1da177e4 | 4764 | |
4bd77321 | 4765 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
4766 | printk(KERN_INFO |
4767 | " task PC stack pid father\n"); | |
1da177e4 | 4768 | #else |
3df0fc5b PZ |
4769 | printk(KERN_INFO |
4770 | " task PC stack pid father\n"); | |
1da177e4 | 4771 | #endif |
510f5acc | 4772 | rcu_read_lock(); |
1da177e4 LT |
4773 | do_each_thread(g, p) { |
4774 | /* | |
4775 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 4776 | * console might take a lot of time: |
1da177e4 LT |
4777 | */ |
4778 | touch_nmi_watchdog(); | |
39bc89fd | 4779 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 4780 | sched_show_task(p); |
1da177e4 LT |
4781 | } while_each_thread(g, p); |
4782 | ||
04c9167f JF |
4783 | touch_all_softlockup_watchdogs(); |
4784 | ||
dd41f596 IM |
4785 | #ifdef CONFIG_SCHED_DEBUG |
4786 | sysrq_sched_debug_show(); | |
4787 | #endif | |
510f5acc | 4788 | rcu_read_unlock(); |
e59e2ae2 IM |
4789 | /* |
4790 | * Only show locks if all tasks are dumped: | |
4791 | */ | |
93335a21 | 4792 | if (!state_filter) |
e59e2ae2 | 4793 | debug_show_all_locks(); |
1da177e4 LT |
4794 | } |
4795 | ||
1df21055 IM |
4796 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
4797 | { | |
dd41f596 | 4798 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
4799 | } |
4800 | ||
f340c0d1 IM |
4801 | /** |
4802 | * init_idle - set up an idle thread for a given CPU | |
4803 | * @idle: task in question | |
4804 | * @cpu: cpu the idle task belongs to | |
4805 | * | |
4806 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
4807 | * flag, to make booting more robust. | |
4808 | */ | |
5c1e1767 | 4809 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 4810 | { |
70b97a7f | 4811 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
4812 | unsigned long flags; |
4813 | ||
05fa785c | 4814 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 4815 | |
dd41f596 | 4816 | __sched_fork(idle); |
06b83b5f | 4817 | idle->state = TASK_RUNNING; |
dd41f596 IM |
4818 | idle->se.exec_start = sched_clock(); |
4819 | ||
1e1b6c51 | 4820 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
4821 | /* |
4822 | * We're having a chicken and egg problem, even though we are | |
4823 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
4824 | * lockdep check in task_group() will fail. | |
4825 | * | |
4826 | * Similar case to sched_fork(). / Alternatively we could | |
4827 | * use task_rq_lock() here and obtain the other rq->lock. | |
4828 | * | |
4829 | * Silence PROVE_RCU | |
4830 | */ | |
4831 | rcu_read_lock(); | |
dd41f596 | 4832 | __set_task_cpu(idle, cpu); |
6506cf6c | 4833 | rcu_read_unlock(); |
1da177e4 | 4834 | |
1da177e4 | 4835 | rq->curr = rq->idle = idle; |
3ca7a440 PZ |
4836 | #if defined(CONFIG_SMP) |
4837 | idle->on_cpu = 1; | |
4866cde0 | 4838 | #endif |
05fa785c | 4839 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
4840 | |
4841 | /* Set the preempt count _outside_ the spinlocks! */ | |
a1261f54 | 4842 | task_thread_info(idle)->preempt_count = 0; |
625f2a37 | 4843 | |
dd41f596 IM |
4844 | /* |
4845 | * The idle tasks have their own, simple scheduling class: | |
4846 | */ | |
4847 | idle->sched_class = &idle_sched_class; | |
868baf07 | 4848 | ftrace_graph_init_idle_task(idle, cpu); |
f1c6f1a7 CE |
4849 | #if defined(CONFIG_SMP) |
4850 | sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); | |
4851 | #endif | |
1da177e4 LT |
4852 | } |
4853 | ||
1da177e4 | 4854 | #ifdef CONFIG_SMP |
1e1b6c51 KM |
4855 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
4856 | { | |
4857 | if (p->sched_class && p->sched_class->set_cpus_allowed) | |
4858 | p->sched_class->set_cpus_allowed(p, new_mask); | |
4939602a PZ |
4859 | |
4860 | cpumask_copy(&p->cpus_allowed, new_mask); | |
4861 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
1e1b6c51 KM |
4862 | } |
4863 | ||
1da177e4 LT |
4864 | /* |
4865 | * This is how migration works: | |
4866 | * | |
969c7921 TH |
4867 | * 1) we invoke migration_cpu_stop() on the target CPU using |
4868 | * stop_one_cpu(). | |
4869 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
4870 | * off the CPU) | |
4871 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
4872 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 4873 | * it and puts it into the right queue. |
969c7921 TH |
4874 | * 5) stopper completes and stop_one_cpu() returns and the migration |
4875 | * is done. | |
1da177e4 LT |
4876 | */ |
4877 | ||
4878 | /* | |
4879 | * Change a given task's CPU affinity. Migrate the thread to a | |
4880 | * proper CPU and schedule it away if the CPU it's executing on | |
4881 | * is removed from the allowed bitmask. | |
4882 | * | |
4883 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 4884 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
4885 | * call is not atomic; no spinlocks may be held. |
4886 | */ | |
96f874e2 | 4887 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
4888 | { |
4889 | unsigned long flags; | |
70b97a7f | 4890 | struct rq *rq; |
969c7921 | 4891 | unsigned int dest_cpu; |
48f24c4d | 4892 | int ret = 0; |
1da177e4 LT |
4893 | |
4894 | rq = task_rq_lock(p, &flags); | |
e2912009 | 4895 | |
db44fc01 YZ |
4896 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
4897 | goto out; | |
4898 | ||
6ad4c188 | 4899 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
4900 | ret = -EINVAL; |
4901 | goto out; | |
4902 | } | |
4903 | ||
db44fc01 | 4904 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { |
9985b0ba DR |
4905 | ret = -EINVAL; |
4906 | goto out; | |
4907 | } | |
4908 | ||
1e1b6c51 | 4909 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 4910 | |
1da177e4 | 4911 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 4912 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
4913 | goto out; |
4914 | ||
969c7921 | 4915 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 4916 | if (p->on_rq) { |
969c7921 | 4917 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 4918 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 4919 | task_rq_unlock(rq, p, &flags); |
969c7921 | 4920 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
4921 | tlb_migrate_finish(p->mm); |
4922 | return 0; | |
4923 | } | |
4924 | out: | |
0122ec5b | 4925 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 4926 | |
1da177e4 LT |
4927 | return ret; |
4928 | } | |
cd8ba7cd | 4929 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
4930 | |
4931 | /* | |
41a2d6cf | 4932 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
4933 | * this because either it can't run here any more (set_cpus_allowed() |
4934 | * away from this CPU, or CPU going down), or because we're | |
4935 | * attempting to rebalance this task on exec (sched_exec). | |
4936 | * | |
4937 | * So we race with normal scheduler movements, but that's OK, as long | |
4938 | * as the task is no longer on this CPU. | |
efc30814 KK |
4939 | * |
4940 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 4941 | */ |
efc30814 | 4942 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 4943 | { |
70b97a7f | 4944 | struct rq *rq_dest, *rq_src; |
e2912009 | 4945 | int ret = 0; |
1da177e4 | 4946 | |
e761b772 | 4947 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 4948 | return ret; |
1da177e4 LT |
4949 | |
4950 | rq_src = cpu_rq(src_cpu); | |
4951 | rq_dest = cpu_rq(dest_cpu); | |
4952 | ||
0122ec5b | 4953 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
4954 | double_rq_lock(rq_src, rq_dest); |
4955 | /* Already moved. */ | |
4956 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 4957 | goto done; |
1da177e4 | 4958 | /* Affinity changed (again). */ |
fa17b507 | 4959 | if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
b1e38734 | 4960 | goto fail; |
1da177e4 | 4961 | |
e2912009 PZ |
4962 | /* |
4963 | * If we're not on a rq, the next wake-up will ensure we're | |
4964 | * placed properly. | |
4965 | */ | |
fd2f4419 | 4966 | if (p->on_rq) { |
2e1cb74a | 4967 | deactivate_task(rq_src, p, 0); |
e2912009 | 4968 | set_task_cpu(p, dest_cpu); |
dd41f596 | 4969 | activate_task(rq_dest, p, 0); |
15afe09b | 4970 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 4971 | } |
b1e38734 | 4972 | done: |
efc30814 | 4973 | ret = 1; |
b1e38734 | 4974 | fail: |
1da177e4 | 4975 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 4976 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 4977 | return ret; |
1da177e4 LT |
4978 | } |
4979 | ||
4980 | /* | |
969c7921 TH |
4981 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
4982 | * and performs thread migration by bumping thread off CPU then | |
4983 | * 'pushing' onto another runqueue. | |
1da177e4 | 4984 | */ |
969c7921 | 4985 | static int migration_cpu_stop(void *data) |
1da177e4 | 4986 | { |
969c7921 | 4987 | struct migration_arg *arg = data; |
f7b4cddc | 4988 | |
969c7921 TH |
4989 | /* |
4990 | * The original target cpu might have gone down and we might | |
4991 | * be on another cpu but it doesn't matter. | |
4992 | */ | |
f7b4cddc | 4993 | local_irq_disable(); |
969c7921 | 4994 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 4995 | local_irq_enable(); |
1da177e4 | 4996 | return 0; |
f7b4cddc ON |
4997 | } |
4998 | ||
1da177e4 | 4999 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 5000 | |
054b9108 | 5001 | /* |
48c5ccae PZ |
5002 | * Ensures that the idle task is using init_mm right before its cpu goes |
5003 | * offline. | |
054b9108 | 5004 | */ |
48c5ccae | 5005 | void idle_task_exit(void) |
1da177e4 | 5006 | { |
48c5ccae | 5007 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 5008 | |
48c5ccae | 5009 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 5010 | |
48c5ccae PZ |
5011 | if (mm != &init_mm) |
5012 | switch_mm(mm, &init_mm, current); | |
5013 | mmdrop(mm); | |
1da177e4 LT |
5014 | } |
5015 | ||
5016 | /* | |
5017 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
5018 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
5019 | * for performance reasons the counter is not stricly tracking tasks to | |
5020 | * their home CPUs. So we just add the counter to another CPU's counter, | |
5021 | * to keep the global sum constant after CPU-down: | |
5022 | */ | |
70b97a7f | 5023 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 5024 | { |
6ad4c188 | 5025 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 | 5026 | |
1da177e4 LT |
5027 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; |
5028 | rq_src->nr_uninterruptible = 0; | |
1da177e4 LT |
5029 | } |
5030 | ||
dd41f596 | 5031 | /* |
48c5ccae | 5032 | * remove the tasks which were accounted by rq from calc_load_tasks. |
1da177e4 | 5033 | */ |
48c5ccae | 5034 | static void calc_global_load_remove(struct rq *rq) |
1da177e4 | 5035 | { |
48c5ccae PZ |
5036 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); |
5037 | rq->calc_load_active = 0; | |
1da177e4 LT |
5038 | } |
5039 | ||
48f24c4d | 5040 | /* |
48c5ccae PZ |
5041 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
5042 | * try_to_wake_up()->select_task_rq(). | |
5043 | * | |
5044 | * Called with rq->lock held even though we'er in stop_machine() and | |
5045 | * there's no concurrency possible, we hold the required locks anyway | |
5046 | * because of lock validation efforts. | |
1da177e4 | 5047 | */ |
48c5ccae | 5048 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 5049 | { |
70b97a7f | 5050 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
5051 | struct task_struct *next, *stop = rq->stop; |
5052 | int dest_cpu; | |
1da177e4 LT |
5053 | |
5054 | /* | |
48c5ccae PZ |
5055 | * Fudge the rq selection such that the below task selection loop |
5056 | * doesn't get stuck on the currently eligible stop task. | |
5057 | * | |
5058 | * We're currently inside stop_machine() and the rq is either stuck | |
5059 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
5060 | * either way we should never end up calling schedule() until we're | |
5061 | * done here. | |
1da177e4 | 5062 | */ |
48c5ccae | 5063 | rq->stop = NULL; |
48f24c4d | 5064 | |
8cb120d3 PT |
5065 | /* Ensure any throttled groups are reachable by pick_next_task */ |
5066 | unthrottle_offline_cfs_rqs(rq); | |
5067 | ||
dd41f596 | 5068 | for ( ; ; ) { |
48c5ccae PZ |
5069 | /* |
5070 | * There's this thread running, bail when that's the only | |
5071 | * remaining thread. | |
5072 | */ | |
5073 | if (rq->nr_running == 1) | |
dd41f596 | 5074 | break; |
48c5ccae | 5075 | |
b67802ea | 5076 | next = pick_next_task(rq); |
48c5ccae | 5077 | BUG_ON(!next); |
79c53799 | 5078 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 5079 | |
48c5ccae PZ |
5080 | /* Find suitable destination for @next, with force if needed. */ |
5081 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
5082 | raw_spin_unlock(&rq->lock); | |
5083 | ||
5084 | __migrate_task(next, dead_cpu, dest_cpu); | |
5085 | ||
5086 | raw_spin_lock(&rq->lock); | |
1da177e4 | 5087 | } |
dce48a84 | 5088 | |
48c5ccae | 5089 | rq->stop = stop; |
dce48a84 | 5090 | } |
48c5ccae | 5091 | |
1da177e4 LT |
5092 | #endif /* CONFIG_HOTPLUG_CPU */ |
5093 | ||
e692ab53 NP |
5094 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
5095 | ||
5096 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
5097 | { |
5098 | .procname = "sched_domain", | |
c57baf1e | 5099 | .mode = 0555, |
e0361851 | 5100 | }, |
56992309 | 5101 | {} |
e692ab53 NP |
5102 | }; |
5103 | ||
5104 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
5105 | { |
5106 | .procname = "kernel", | |
c57baf1e | 5107 | .mode = 0555, |
e0361851 AD |
5108 | .child = sd_ctl_dir, |
5109 | }, | |
56992309 | 5110 | {} |
e692ab53 NP |
5111 | }; |
5112 | ||
5113 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
5114 | { | |
5115 | struct ctl_table *entry = | |
5cf9f062 | 5116 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 5117 | |
e692ab53 NP |
5118 | return entry; |
5119 | } | |
5120 | ||
6382bc90 MM |
5121 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
5122 | { | |
cd790076 | 5123 | struct ctl_table *entry; |
6382bc90 | 5124 | |
cd790076 MM |
5125 | /* |
5126 | * In the intermediate directories, both the child directory and | |
5127 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 5128 | * will always be set. In the lowest directory the names are |
cd790076 MM |
5129 | * static strings and all have proc handlers. |
5130 | */ | |
5131 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
5132 | if (entry->child) |
5133 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
5134 | if (entry->proc_handler == NULL) |
5135 | kfree(entry->procname); | |
5136 | } | |
6382bc90 MM |
5137 | |
5138 | kfree(*tablep); | |
5139 | *tablep = NULL; | |
5140 | } | |
5141 | ||
e692ab53 | 5142 | static void |
e0361851 | 5143 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
5144 | const char *procname, void *data, int maxlen, |
5145 | mode_t mode, proc_handler *proc_handler) | |
5146 | { | |
e692ab53 NP |
5147 | entry->procname = procname; |
5148 | entry->data = data; | |
5149 | entry->maxlen = maxlen; | |
5150 | entry->mode = mode; | |
5151 | entry->proc_handler = proc_handler; | |
5152 | } | |
5153 | ||
5154 | static struct ctl_table * | |
5155 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
5156 | { | |
a5d8c348 | 5157 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 5158 | |
ad1cdc1d MM |
5159 | if (table == NULL) |
5160 | return NULL; | |
5161 | ||
e0361851 | 5162 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 5163 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5164 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 5165 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5166 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 5167 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5168 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 5169 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5170 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 5171 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5172 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 5173 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5174 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 5175 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5176 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 5177 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5178 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 5179 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 5180 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
5181 | &sd->cache_nice_tries, |
5182 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 5183 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 5184 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
5185 | set_table_entry(&table[11], "name", sd->name, |
5186 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
5187 | /* &table[12] is terminator */ | |
e692ab53 NP |
5188 | |
5189 | return table; | |
5190 | } | |
5191 | ||
9a4e7159 | 5192 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
5193 | { |
5194 | struct ctl_table *entry, *table; | |
5195 | struct sched_domain *sd; | |
5196 | int domain_num = 0, i; | |
5197 | char buf[32]; | |
5198 | ||
5199 | for_each_domain(cpu, sd) | |
5200 | domain_num++; | |
5201 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5202 | if (table == NULL) |
5203 | return NULL; | |
e692ab53 NP |
5204 | |
5205 | i = 0; | |
5206 | for_each_domain(cpu, sd) { | |
5207 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5208 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5209 | entry->mode = 0555; |
e692ab53 NP |
5210 | entry->child = sd_alloc_ctl_domain_table(sd); |
5211 | entry++; | |
5212 | i++; | |
5213 | } | |
5214 | return table; | |
5215 | } | |
5216 | ||
5217 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5218 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5219 | { |
6ad4c188 | 5220 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5221 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5222 | char buf[32]; | |
5223 | ||
7378547f MM |
5224 | WARN_ON(sd_ctl_dir[0].child); |
5225 | sd_ctl_dir[0].child = entry; | |
5226 | ||
ad1cdc1d MM |
5227 | if (entry == NULL) |
5228 | return; | |
5229 | ||
6ad4c188 | 5230 | for_each_possible_cpu(i) { |
e692ab53 | 5231 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5232 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5233 | entry->mode = 0555; |
e692ab53 | 5234 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5235 | entry++; |
e692ab53 | 5236 | } |
7378547f MM |
5237 | |
5238 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5239 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5240 | } | |
6382bc90 | 5241 | |
7378547f | 5242 | /* may be called multiple times per register */ |
6382bc90 MM |
5243 | static void unregister_sched_domain_sysctl(void) |
5244 | { | |
7378547f MM |
5245 | if (sd_sysctl_header) |
5246 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5247 | sd_sysctl_header = NULL; |
7378547f MM |
5248 | if (sd_ctl_dir[0].child) |
5249 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5250 | } |
e692ab53 | 5251 | #else |
6382bc90 MM |
5252 | static void register_sched_domain_sysctl(void) |
5253 | { | |
5254 | } | |
5255 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5256 | { |
5257 | } | |
5258 | #endif | |
5259 | ||
1f11eb6a GH |
5260 | static void set_rq_online(struct rq *rq) |
5261 | { | |
5262 | if (!rq->online) { | |
5263 | const struct sched_class *class; | |
5264 | ||
c6c4927b | 5265 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5266 | rq->online = 1; |
5267 | ||
5268 | for_each_class(class) { | |
5269 | if (class->rq_online) | |
5270 | class->rq_online(rq); | |
5271 | } | |
5272 | } | |
5273 | } | |
5274 | ||
5275 | static void set_rq_offline(struct rq *rq) | |
5276 | { | |
5277 | if (rq->online) { | |
5278 | const struct sched_class *class; | |
5279 | ||
5280 | for_each_class(class) { | |
5281 | if (class->rq_offline) | |
5282 | class->rq_offline(rq); | |
5283 | } | |
5284 | ||
c6c4927b | 5285 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5286 | rq->online = 0; |
5287 | } | |
5288 | } | |
5289 | ||
1da177e4 LT |
5290 | /* |
5291 | * migration_call - callback that gets triggered when a CPU is added. | |
5292 | * Here we can start up the necessary migration thread for the new CPU. | |
5293 | */ | |
48f24c4d IM |
5294 | static int __cpuinit |
5295 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 5296 | { |
48f24c4d | 5297 | int cpu = (long)hcpu; |
1da177e4 | 5298 | unsigned long flags; |
969c7921 | 5299 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 5300 | |
48c5ccae | 5301 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 5302 | |
1da177e4 | 5303 | case CPU_UP_PREPARE: |
a468d389 | 5304 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5305 | break; |
48f24c4d | 5306 | |
1da177e4 | 5307 | case CPU_ONLINE: |
1f94ef59 | 5308 | /* Update our root-domain */ |
05fa785c | 5309 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5310 | if (rq->rd) { |
c6c4927b | 5311 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5312 | |
5313 | set_rq_online(rq); | |
1f94ef59 | 5314 | } |
05fa785c | 5315 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5316 | break; |
48f24c4d | 5317 | |
1da177e4 | 5318 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 5319 | case CPU_DYING: |
317f3941 | 5320 | sched_ttwu_pending(); |
57d885fe | 5321 | /* Update our root-domain */ |
05fa785c | 5322 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5323 | if (rq->rd) { |
c6c4927b | 5324 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5325 | set_rq_offline(rq); |
57d885fe | 5326 | } |
48c5ccae PZ |
5327 | migrate_tasks(cpu); |
5328 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 5329 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
48c5ccae PZ |
5330 | |
5331 | migrate_nr_uninterruptible(rq); | |
5332 | calc_global_load_remove(rq); | |
57d885fe | 5333 | break; |
1da177e4 LT |
5334 | #endif |
5335 | } | |
49c022e6 PZ |
5336 | |
5337 | update_max_interval(); | |
5338 | ||
1da177e4 LT |
5339 | return NOTIFY_OK; |
5340 | } | |
5341 | ||
f38b0820 PM |
5342 | /* |
5343 | * Register at high priority so that task migration (migrate_all_tasks) | |
5344 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5345 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5346 | */ |
26c2143b | 5347 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 | 5348 | .notifier_call = migration_call, |
50a323b7 | 5349 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
5350 | }; |
5351 | ||
3a101d05 TH |
5352 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, |
5353 | unsigned long action, void *hcpu) | |
5354 | { | |
5355 | switch (action & ~CPU_TASKS_FROZEN) { | |
5356 | case CPU_ONLINE: | |
5357 | case CPU_DOWN_FAILED: | |
5358 | set_cpu_active((long)hcpu, true); | |
5359 | return NOTIFY_OK; | |
5360 | default: | |
5361 | return NOTIFY_DONE; | |
5362 | } | |
5363 | } | |
5364 | ||
5365 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | |
5366 | unsigned long action, void *hcpu) | |
5367 | { | |
5368 | switch (action & ~CPU_TASKS_FROZEN) { | |
5369 | case CPU_DOWN_PREPARE: | |
5370 | set_cpu_active((long)hcpu, false); | |
5371 | return NOTIFY_OK; | |
5372 | default: | |
5373 | return NOTIFY_DONE; | |
5374 | } | |
5375 | } | |
5376 | ||
7babe8db | 5377 | static int __init migration_init(void) |
1da177e4 LT |
5378 | { |
5379 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5380 | int err; |
48f24c4d | 5381 | |
3a101d05 | 5382 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
5383 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5384 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5385 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5386 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5387 | |
3a101d05 TH |
5388 | /* Register cpu active notifiers */ |
5389 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
5390 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
5391 | ||
a004cd42 | 5392 | return 0; |
1da177e4 | 5393 | } |
7babe8db | 5394 | early_initcall(migration_init); |
1da177e4 LT |
5395 | #endif |
5396 | ||
5397 | #ifdef CONFIG_SMP | |
476f3534 | 5398 | |
4cb98839 PZ |
5399 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
5400 | ||
3e9830dc | 5401 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5402 | |
f6630114 MT |
5403 | static __read_mostly int sched_domain_debug_enabled; |
5404 | ||
5405 | static int __init sched_domain_debug_setup(char *str) | |
5406 | { | |
5407 | sched_domain_debug_enabled = 1; | |
5408 | ||
5409 | return 0; | |
5410 | } | |
5411 | early_param("sched_debug", sched_domain_debug_setup); | |
5412 | ||
7c16ec58 | 5413 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5414 | struct cpumask *groupmask) |
1da177e4 | 5415 | { |
4dcf6aff | 5416 | struct sched_group *group = sd->groups; |
434d53b0 | 5417 | char str[256]; |
1da177e4 | 5418 | |
968ea6d8 | 5419 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5420 | cpumask_clear(groupmask); |
4dcf6aff IM |
5421 | |
5422 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5423 | ||
5424 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5425 | printk("does not load-balance\n"); |
4dcf6aff | 5426 | if (sd->parent) |
3df0fc5b PZ |
5427 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5428 | " has parent"); | |
4dcf6aff | 5429 | return -1; |
41c7ce9a NP |
5430 | } |
5431 | ||
3df0fc5b | 5432 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5433 | |
758b2cdc | 5434 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5435 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5436 | "CPU%d\n", cpu); | |
4dcf6aff | 5437 | } |
758b2cdc | 5438 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5439 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5440 | " CPU%d\n", cpu); | |
4dcf6aff | 5441 | } |
1da177e4 | 5442 | |
4dcf6aff | 5443 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5444 | do { |
4dcf6aff | 5445 | if (!group) { |
3df0fc5b PZ |
5446 | printk("\n"); |
5447 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5448 | break; |
5449 | } | |
5450 | ||
9c3f75cb | 5451 | if (!group->sgp->power) { |
3df0fc5b PZ |
5452 | printk(KERN_CONT "\n"); |
5453 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
5454 | "set\n"); | |
4dcf6aff IM |
5455 | break; |
5456 | } | |
1da177e4 | 5457 | |
758b2cdc | 5458 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5459 | printk(KERN_CONT "\n"); |
5460 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5461 | break; |
5462 | } | |
1da177e4 | 5463 | |
758b2cdc | 5464 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
5465 | printk(KERN_CONT "\n"); |
5466 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5467 | break; |
5468 | } | |
1da177e4 | 5469 | |
758b2cdc | 5470 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5471 | |
968ea6d8 | 5472 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5473 | |
3df0fc5b | 5474 | printk(KERN_CONT " %s", str); |
9c3f75cb | 5475 | if (group->sgp->power != SCHED_POWER_SCALE) { |
3df0fc5b | 5476 | printk(KERN_CONT " (cpu_power = %d)", |
9c3f75cb | 5477 | group->sgp->power); |
381512cf | 5478 | } |
1da177e4 | 5479 | |
4dcf6aff IM |
5480 | group = group->next; |
5481 | } while (group != sd->groups); | |
3df0fc5b | 5482 | printk(KERN_CONT "\n"); |
1da177e4 | 5483 | |
758b2cdc | 5484 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 5485 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 5486 | |
758b2cdc RR |
5487 | if (sd->parent && |
5488 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
5489 | printk(KERN_ERR "ERROR: parent span is not a superset " |
5490 | "of domain->span\n"); | |
4dcf6aff IM |
5491 | return 0; |
5492 | } | |
1da177e4 | 5493 | |
4dcf6aff IM |
5494 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
5495 | { | |
5496 | int level = 0; | |
1da177e4 | 5497 | |
f6630114 MT |
5498 | if (!sched_domain_debug_enabled) |
5499 | return; | |
5500 | ||
4dcf6aff IM |
5501 | if (!sd) { |
5502 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
5503 | return; | |
5504 | } | |
1da177e4 | 5505 | |
4dcf6aff IM |
5506 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
5507 | ||
5508 | for (;;) { | |
4cb98839 | 5509 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 5510 | break; |
1da177e4 LT |
5511 | level++; |
5512 | sd = sd->parent; | |
33859f7f | 5513 | if (!sd) |
4dcf6aff IM |
5514 | break; |
5515 | } | |
1da177e4 | 5516 | } |
6d6bc0ad | 5517 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 5518 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 5519 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 5520 | |
1a20ff27 | 5521 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 5522 | { |
758b2cdc | 5523 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
5524 | return 1; |
5525 | ||
5526 | /* Following flags need at least 2 groups */ | |
5527 | if (sd->flags & (SD_LOAD_BALANCE | | |
5528 | SD_BALANCE_NEWIDLE | | |
5529 | SD_BALANCE_FORK | | |
89c4710e SS |
5530 | SD_BALANCE_EXEC | |
5531 | SD_SHARE_CPUPOWER | | |
5532 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
5533 | if (sd->groups != sd->groups->next) |
5534 | return 0; | |
5535 | } | |
5536 | ||
5537 | /* Following flags don't use groups */ | |
c88d5910 | 5538 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
5539 | return 0; |
5540 | ||
5541 | return 1; | |
5542 | } | |
5543 | ||
48f24c4d IM |
5544 | static int |
5545 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
5546 | { |
5547 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
5548 | ||
5549 | if (sd_degenerate(parent)) | |
5550 | return 1; | |
5551 | ||
758b2cdc | 5552 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
5553 | return 0; |
5554 | ||
245af2c7 SS |
5555 | /* Flags needing groups don't count if only 1 group in parent */ |
5556 | if (parent->groups == parent->groups->next) { | |
5557 | pflags &= ~(SD_LOAD_BALANCE | | |
5558 | SD_BALANCE_NEWIDLE | | |
5559 | SD_BALANCE_FORK | | |
89c4710e SS |
5560 | SD_BALANCE_EXEC | |
5561 | SD_SHARE_CPUPOWER | | |
5562 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
5563 | if (nr_node_ids == 1) |
5564 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
5565 | } |
5566 | if (~cflags & pflags) | |
5567 | return 0; | |
5568 | ||
5569 | return 1; | |
5570 | } | |
5571 | ||
dce840a0 | 5572 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 5573 | { |
dce840a0 | 5574 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 5575 | |
68e74568 | 5576 | cpupri_cleanup(&rd->cpupri); |
c6c4927b RR |
5577 | free_cpumask_var(rd->rto_mask); |
5578 | free_cpumask_var(rd->online); | |
5579 | free_cpumask_var(rd->span); | |
5580 | kfree(rd); | |
5581 | } | |
5582 | ||
57d885fe GH |
5583 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
5584 | { | |
a0490fa3 | 5585 | struct root_domain *old_rd = NULL; |
57d885fe | 5586 | unsigned long flags; |
57d885fe | 5587 | |
05fa785c | 5588 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
5589 | |
5590 | if (rq->rd) { | |
a0490fa3 | 5591 | old_rd = rq->rd; |
57d885fe | 5592 | |
c6c4927b | 5593 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 5594 | set_rq_offline(rq); |
57d885fe | 5595 | |
c6c4927b | 5596 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 5597 | |
a0490fa3 IM |
5598 | /* |
5599 | * If we dont want to free the old_rt yet then | |
5600 | * set old_rd to NULL to skip the freeing later | |
5601 | * in this function: | |
5602 | */ | |
5603 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
5604 | old_rd = NULL; | |
57d885fe GH |
5605 | } |
5606 | ||
5607 | atomic_inc(&rd->refcount); | |
5608 | rq->rd = rd; | |
5609 | ||
c6c4927b | 5610 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 5611 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 5612 | set_rq_online(rq); |
57d885fe | 5613 | |
05fa785c | 5614 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
5615 | |
5616 | if (old_rd) | |
dce840a0 | 5617 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
5618 | } |
5619 | ||
68c38fc3 | 5620 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
5621 | { |
5622 | memset(rd, 0, sizeof(*rd)); | |
5623 | ||
68c38fc3 | 5624 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 5625 | goto out; |
68c38fc3 | 5626 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 5627 | goto free_span; |
68c38fc3 | 5628 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
c6c4927b | 5629 | goto free_online; |
6e0534f2 | 5630 | |
68c38fc3 | 5631 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 5632 | goto free_rto_mask; |
c6c4927b | 5633 | return 0; |
6e0534f2 | 5634 | |
68e74568 RR |
5635 | free_rto_mask: |
5636 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
5637 | free_online: |
5638 | free_cpumask_var(rd->online); | |
5639 | free_span: | |
5640 | free_cpumask_var(rd->span); | |
0c910d28 | 5641 | out: |
c6c4927b | 5642 | return -ENOMEM; |
57d885fe GH |
5643 | } |
5644 | ||
029632fb PZ |
5645 | /* |
5646 | * By default the system creates a single root-domain with all cpus as | |
5647 | * members (mimicking the global state we have today). | |
5648 | */ | |
5649 | struct root_domain def_root_domain; | |
5650 | ||
57d885fe GH |
5651 | static void init_defrootdomain(void) |
5652 | { | |
68c38fc3 | 5653 | init_rootdomain(&def_root_domain); |
c6c4927b | 5654 | |
57d885fe GH |
5655 | atomic_set(&def_root_domain.refcount, 1); |
5656 | } | |
5657 | ||
dc938520 | 5658 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
5659 | { |
5660 | struct root_domain *rd; | |
5661 | ||
5662 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
5663 | if (!rd) | |
5664 | return NULL; | |
5665 | ||
68c38fc3 | 5666 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
5667 | kfree(rd); |
5668 | return NULL; | |
5669 | } | |
57d885fe GH |
5670 | |
5671 | return rd; | |
5672 | } | |
5673 | ||
e3589f6c PZ |
5674 | static void free_sched_groups(struct sched_group *sg, int free_sgp) |
5675 | { | |
5676 | struct sched_group *tmp, *first; | |
5677 | ||
5678 | if (!sg) | |
5679 | return; | |
5680 | ||
5681 | first = sg; | |
5682 | do { | |
5683 | tmp = sg->next; | |
5684 | ||
5685 | if (free_sgp && atomic_dec_and_test(&sg->sgp->ref)) | |
5686 | kfree(sg->sgp); | |
5687 | ||
5688 | kfree(sg); | |
5689 | sg = tmp; | |
5690 | } while (sg != first); | |
5691 | } | |
5692 | ||
dce840a0 PZ |
5693 | static void free_sched_domain(struct rcu_head *rcu) |
5694 | { | |
5695 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
5696 | |
5697 | /* | |
5698 | * If its an overlapping domain it has private groups, iterate and | |
5699 | * nuke them all. | |
5700 | */ | |
5701 | if (sd->flags & SD_OVERLAP) { | |
5702 | free_sched_groups(sd->groups, 1); | |
5703 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
9c3f75cb | 5704 | kfree(sd->groups->sgp); |
dce840a0 | 5705 | kfree(sd->groups); |
9c3f75cb | 5706 | } |
dce840a0 PZ |
5707 | kfree(sd); |
5708 | } | |
5709 | ||
5710 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
5711 | { | |
5712 | call_rcu(&sd->rcu, free_sched_domain); | |
5713 | } | |
5714 | ||
5715 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
5716 | { | |
5717 | for (; sd; sd = sd->parent) | |
5718 | destroy_sched_domain(sd, cpu); | |
5719 | } | |
5720 | ||
1da177e4 | 5721 | /* |
0eab9146 | 5722 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
5723 | * hold the hotplug lock. |
5724 | */ | |
0eab9146 IM |
5725 | static void |
5726 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 5727 | { |
70b97a7f | 5728 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
5729 | struct sched_domain *tmp; |
5730 | ||
5731 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 5732 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
5733 | struct sched_domain *parent = tmp->parent; |
5734 | if (!parent) | |
5735 | break; | |
f29c9b1c | 5736 | |
1a848870 | 5737 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 5738 | tmp->parent = parent->parent; |
1a848870 SS |
5739 | if (parent->parent) |
5740 | parent->parent->child = tmp; | |
dce840a0 | 5741 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
5742 | } else |
5743 | tmp = tmp->parent; | |
245af2c7 SS |
5744 | } |
5745 | ||
1a848870 | 5746 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 5747 | tmp = sd; |
245af2c7 | 5748 | sd = sd->parent; |
dce840a0 | 5749 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
5750 | if (sd) |
5751 | sd->child = NULL; | |
5752 | } | |
1da177e4 | 5753 | |
4cb98839 | 5754 | sched_domain_debug(sd, cpu); |
1da177e4 | 5755 | |
57d885fe | 5756 | rq_attach_root(rq, rd); |
dce840a0 | 5757 | tmp = rq->sd; |
674311d5 | 5758 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 5759 | destroy_sched_domains(tmp, cpu); |
1da177e4 LT |
5760 | } |
5761 | ||
5762 | /* cpus with isolated domains */ | |
dcc30a35 | 5763 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
5764 | |
5765 | /* Setup the mask of cpus configured for isolated domains */ | |
5766 | static int __init isolated_cpu_setup(char *str) | |
5767 | { | |
bdddd296 | 5768 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 5769 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
5770 | return 1; |
5771 | } | |
5772 | ||
8927f494 | 5773 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 5774 | |
9c1cfda2 | 5775 | #ifdef CONFIG_NUMA |
198e2f18 | 5776 | |
9c1cfda2 JH |
5777 | /** |
5778 | * find_next_best_node - find the next node to include in a sched_domain | |
5779 | * @node: node whose sched_domain we're building | |
5780 | * @used_nodes: nodes already in the sched_domain | |
5781 | * | |
41a2d6cf | 5782 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
5783 | * finds the closest node not already in the @used_nodes map. |
5784 | * | |
5785 | * Should use nodemask_t. | |
5786 | */ | |
c5f59f08 | 5787 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 | 5788 | { |
7142d17e | 5789 | int i, n, val, min_val, best_node = -1; |
9c1cfda2 JH |
5790 | |
5791 | min_val = INT_MAX; | |
5792 | ||
076ac2af | 5793 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 5794 | /* Start at @node */ |
076ac2af | 5795 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
5796 | |
5797 | if (!nr_cpus_node(n)) | |
5798 | continue; | |
5799 | ||
5800 | /* Skip already used nodes */ | |
c5f59f08 | 5801 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
5802 | continue; |
5803 | ||
5804 | /* Simple min distance search */ | |
5805 | val = node_distance(node, n); | |
5806 | ||
5807 | if (val < min_val) { | |
5808 | min_val = val; | |
5809 | best_node = n; | |
5810 | } | |
5811 | } | |
5812 | ||
7142d17e HD |
5813 | if (best_node != -1) |
5814 | node_set(best_node, *used_nodes); | |
9c1cfda2 JH |
5815 | return best_node; |
5816 | } | |
5817 | ||
5818 | /** | |
5819 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
5820 | * @node: node whose cpumask we're constructing | |
73486722 | 5821 | * @span: resulting cpumask |
9c1cfda2 | 5822 | * |
41a2d6cf | 5823 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
5824 | * should be one that prevents unnecessary balancing, but also spreads tasks |
5825 | * out optimally. | |
5826 | */ | |
96f874e2 | 5827 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 5828 | { |
c5f59f08 | 5829 | nodemask_t used_nodes; |
48f24c4d | 5830 | int i; |
9c1cfda2 | 5831 | |
6ca09dfc | 5832 | cpumask_clear(span); |
c5f59f08 | 5833 | nodes_clear(used_nodes); |
9c1cfda2 | 5834 | |
6ca09dfc | 5835 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 5836 | node_set(node, used_nodes); |
9c1cfda2 JH |
5837 | |
5838 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 5839 | int next_node = find_next_best_node(node, &used_nodes); |
7142d17e HD |
5840 | if (next_node < 0) |
5841 | break; | |
6ca09dfc | 5842 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 5843 | } |
9c1cfda2 | 5844 | } |
d3081f52 PZ |
5845 | |
5846 | static const struct cpumask *cpu_node_mask(int cpu) | |
5847 | { | |
5848 | lockdep_assert_held(&sched_domains_mutex); | |
5849 | ||
5850 | sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask); | |
5851 | ||
5852 | return sched_domains_tmpmask; | |
5853 | } | |
2c402dc3 PZ |
5854 | |
5855 | static const struct cpumask *cpu_allnodes_mask(int cpu) | |
5856 | { | |
5857 | return cpu_possible_mask; | |
5858 | } | |
6d6bc0ad | 5859 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 5860 | |
d3081f52 PZ |
5861 | static const struct cpumask *cpu_cpu_mask(int cpu) |
5862 | { | |
5863 | return cpumask_of_node(cpu_to_node(cpu)); | |
5864 | } | |
5865 | ||
5c45bf27 | 5866 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 5867 | |
dce840a0 PZ |
5868 | struct sd_data { |
5869 | struct sched_domain **__percpu sd; | |
5870 | struct sched_group **__percpu sg; | |
9c3f75cb | 5871 | struct sched_group_power **__percpu sgp; |
dce840a0 PZ |
5872 | }; |
5873 | ||
49a02c51 | 5874 | struct s_data { |
21d42ccf | 5875 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
5876 | struct root_domain *rd; |
5877 | }; | |
5878 | ||
2109b99e | 5879 | enum s_alloc { |
2109b99e | 5880 | sa_rootdomain, |
21d42ccf | 5881 | sa_sd, |
dce840a0 | 5882 | sa_sd_storage, |
2109b99e AH |
5883 | sa_none, |
5884 | }; | |
5885 | ||
54ab4ff4 PZ |
5886 | struct sched_domain_topology_level; |
5887 | ||
5888 | typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu); | |
eb7a74e6 PZ |
5889 | typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); |
5890 | ||
e3589f6c PZ |
5891 | #define SDTL_OVERLAP 0x01 |
5892 | ||
eb7a74e6 | 5893 | struct sched_domain_topology_level { |
2c402dc3 PZ |
5894 | sched_domain_init_f init; |
5895 | sched_domain_mask_f mask; | |
e3589f6c | 5896 | int flags; |
54ab4ff4 | 5897 | struct sd_data data; |
eb7a74e6 PZ |
5898 | }; |
5899 | ||
e3589f6c PZ |
5900 | static int |
5901 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
5902 | { | |
5903 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
5904 | const struct cpumask *span = sched_domain_span(sd); | |
5905 | struct cpumask *covered = sched_domains_tmpmask; | |
5906 | struct sd_data *sdd = sd->private; | |
5907 | struct sched_domain *child; | |
5908 | int i; | |
5909 | ||
5910 | cpumask_clear(covered); | |
5911 | ||
5912 | for_each_cpu(i, span) { | |
5913 | struct cpumask *sg_span; | |
5914 | ||
5915 | if (cpumask_test_cpu(i, covered)) | |
5916 | continue; | |
5917 | ||
5918 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
4d78a223 | 5919 | GFP_KERNEL, cpu_to_node(cpu)); |
e3589f6c PZ |
5920 | |
5921 | if (!sg) | |
5922 | goto fail; | |
5923 | ||
5924 | sg_span = sched_group_cpus(sg); | |
5925 | ||
5926 | child = *per_cpu_ptr(sdd->sd, i); | |
5927 | if (child->child) { | |
5928 | child = child->child; | |
5929 | cpumask_copy(sg_span, sched_domain_span(child)); | |
5930 | } else | |
5931 | cpumask_set_cpu(i, sg_span); | |
5932 | ||
5933 | cpumask_or(covered, covered, sg_span); | |
5934 | ||
5935 | sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span)); | |
5936 | atomic_inc(&sg->sgp->ref); | |
5937 | ||
5938 | if (cpumask_test_cpu(cpu, sg_span)) | |
5939 | groups = sg; | |
5940 | ||
5941 | if (!first) | |
5942 | first = sg; | |
5943 | if (last) | |
5944 | last->next = sg; | |
5945 | last = sg; | |
5946 | last->next = first; | |
5947 | } | |
5948 | sd->groups = groups; | |
5949 | ||
5950 | return 0; | |
5951 | ||
5952 | fail: | |
5953 | free_sched_groups(first, 0); | |
5954 | ||
5955 | return -ENOMEM; | |
5956 | } | |
5957 | ||
dce840a0 | 5958 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 5959 | { |
dce840a0 PZ |
5960 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
5961 | struct sched_domain *child = sd->child; | |
1da177e4 | 5962 | |
dce840a0 PZ |
5963 | if (child) |
5964 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 5965 | |
9c3f75cb | 5966 | if (sg) { |
dce840a0 | 5967 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
9c3f75cb | 5968 | (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu); |
e3589f6c | 5969 | atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */ |
9c3f75cb | 5970 | } |
dce840a0 PZ |
5971 | |
5972 | return cpu; | |
1e9f28fa | 5973 | } |
1e9f28fa | 5974 | |
01a08546 | 5975 | /* |
dce840a0 PZ |
5976 | * build_sched_groups will build a circular linked list of the groups |
5977 | * covered by the given span, and will set each group's ->cpumask correctly, | |
5978 | * and ->cpu_power to 0. | |
e3589f6c PZ |
5979 | * |
5980 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 5981 | */ |
e3589f6c PZ |
5982 | static int |
5983 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 5984 | { |
dce840a0 PZ |
5985 | struct sched_group *first = NULL, *last = NULL; |
5986 | struct sd_data *sdd = sd->private; | |
5987 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 5988 | struct cpumask *covered; |
dce840a0 | 5989 | int i; |
9c1cfda2 | 5990 | |
e3589f6c PZ |
5991 | get_group(cpu, sdd, &sd->groups); |
5992 | atomic_inc(&sd->groups->ref); | |
5993 | ||
5994 | if (cpu != cpumask_first(sched_domain_span(sd))) | |
5995 | return 0; | |
5996 | ||
f96225fd PZ |
5997 | lockdep_assert_held(&sched_domains_mutex); |
5998 | covered = sched_domains_tmpmask; | |
5999 | ||
dce840a0 | 6000 | cpumask_clear(covered); |
6711cab4 | 6001 | |
dce840a0 PZ |
6002 | for_each_cpu(i, span) { |
6003 | struct sched_group *sg; | |
6004 | int group = get_group(i, sdd, &sg); | |
6005 | int j; | |
6711cab4 | 6006 | |
dce840a0 PZ |
6007 | if (cpumask_test_cpu(i, covered)) |
6008 | continue; | |
6711cab4 | 6009 | |
dce840a0 | 6010 | cpumask_clear(sched_group_cpus(sg)); |
9c3f75cb | 6011 | sg->sgp->power = 0; |
0601a88d | 6012 | |
dce840a0 PZ |
6013 | for_each_cpu(j, span) { |
6014 | if (get_group(j, sdd, NULL) != group) | |
6015 | continue; | |
0601a88d | 6016 | |
dce840a0 PZ |
6017 | cpumask_set_cpu(j, covered); |
6018 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
6019 | } | |
0601a88d | 6020 | |
dce840a0 PZ |
6021 | if (!first) |
6022 | first = sg; | |
6023 | if (last) | |
6024 | last->next = sg; | |
6025 | last = sg; | |
6026 | } | |
6027 | last->next = first; | |
e3589f6c PZ |
6028 | |
6029 | return 0; | |
0601a88d | 6030 | } |
51888ca2 | 6031 | |
89c4710e SS |
6032 | /* |
6033 | * Initialize sched groups cpu_power. | |
6034 | * | |
6035 | * cpu_power indicates the capacity of sched group, which is used while | |
6036 | * distributing the load between different sched groups in a sched domain. | |
6037 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
6038 | * there are asymmetries in the topology. If there are asymmetries, group | |
6039 | * having more cpu_power will pickup more load compared to the group having | |
6040 | * less cpu_power. | |
89c4710e SS |
6041 | */ |
6042 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
6043 | { | |
e3589f6c | 6044 | struct sched_group *sg = sd->groups; |
89c4710e | 6045 | |
e3589f6c PZ |
6046 | WARN_ON(!sd || !sg); |
6047 | ||
6048 | do { | |
6049 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
6050 | sg = sg->next; | |
6051 | } while (sg != sd->groups); | |
89c4710e | 6052 | |
e3589f6c PZ |
6053 | if (cpu != group_first_cpu(sg)) |
6054 | return; | |
aae6d3dd | 6055 | |
d274cb30 | 6056 | update_group_power(sd, cpu); |
69e1e811 | 6057 | atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight); |
89c4710e SS |
6058 | } |
6059 | ||
029632fb PZ |
6060 | int __weak arch_sd_sibling_asym_packing(void) |
6061 | { | |
6062 | return 0*SD_ASYM_PACKING; | |
6063 | } | |
6064 | ||
7c16ec58 MT |
6065 | /* |
6066 | * Initializers for schedule domains | |
6067 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
6068 | */ | |
6069 | ||
a5d8c348 IM |
6070 | #ifdef CONFIG_SCHED_DEBUG |
6071 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
6072 | #else | |
6073 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
6074 | #endif | |
6075 | ||
54ab4ff4 PZ |
6076 | #define SD_INIT_FUNC(type) \ |
6077 | static noinline struct sched_domain * \ | |
6078 | sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \ | |
6079 | { \ | |
6080 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \ | |
6081 | *sd = SD_##type##_INIT; \ | |
54ab4ff4 PZ |
6082 | SD_INIT_NAME(sd, type); \ |
6083 | sd->private = &tl->data; \ | |
6084 | return sd; \ | |
7c16ec58 MT |
6085 | } |
6086 | ||
6087 | SD_INIT_FUNC(CPU) | |
6088 | #ifdef CONFIG_NUMA | |
6089 | SD_INIT_FUNC(ALLNODES) | |
6090 | SD_INIT_FUNC(NODE) | |
6091 | #endif | |
6092 | #ifdef CONFIG_SCHED_SMT | |
6093 | SD_INIT_FUNC(SIBLING) | |
6094 | #endif | |
6095 | #ifdef CONFIG_SCHED_MC | |
6096 | SD_INIT_FUNC(MC) | |
6097 | #endif | |
01a08546 HC |
6098 | #ifdef CONFIG_SCHED_BOOK |
6099 | SD_INIT_FUNC(BOOK) | |
6100 | #endif | |
7c16ec58 | 6101 | |
1d3504fc | 6102 | static int default_relax_domain_level = -1; |
60495e77 | 6103 | int sched_domain_level_max; |
1d3504fc HS |
6104 | |
6105 | static int __init setup_relax_domain_level(char *str) | |
6106 | { | |
30e0e178 LZ |
6107 | unsigned long val; |
6108 | ||
6109 | val = simple_strtoul(str, NULL, 0); | |
60495e77 | 6110 | if (val < sched_domain_level_max) |
30e0e178 LZ |
6111 | default_relax_domain_level = val; |
6112 | ||
1d3504fc HS |
6113 | return 1; |
6114 | } | |
6115 | __setup("relax_domain_level=", setup_relax_domain_level); | |
6116 | ||
6117 | static void set_domain_attribute(struct sched_domain *sd, | |
6118 | struct sched_domain_attr *attr) | |
6119 | { | |
6120 | int request; | |
6121 | ||
6122 | if (!attr || attr->relax_domain_level < 0) { | |
6123 | if (default_relax_domain_level < 0) | |
6124 | return; | |
6125 | else | |
6126 | request = default_relax_domain_level; | |
6127 | } else | |
6128 | request = attr->relax_domain_level; | |
6129 | if (request < sd->level) { | |
6130 | /* turn off idle balance on this domain */ | |
c88d5910 | 6131 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6132 | } else { |
6133 | /* turn on idle balance on this domain */ | |
c88d5910 | 6134 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6135 | } |
6136 | } | |
6137 | ||
54ab4ff4 PZ |
6138 | static void __sdt_free(const struct cpumask *cpu_map); |
6139 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
6140 | ||
2109b99e AH |
6141 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
6142 | const struct cpumask *cpu_map) | |
6143 | { | |
6144 | switch (what) { | |
2109b99e | 6145 | case sa_rootdomain: |
822ff793 PZ |
6146 | if (!atomic_read(&d->rd->refcount)) |
6147 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
6148 | case sa_sd: |
6149 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 6150 | case sa_sd_storage: |
54ab4ff4 | 6151 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
6152 | case sa_none: |
6153 | break; | |
6154 | } | |
6155 | } | |
3404c8d9 | 6156 | |
2109b99e AH |
6157 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
6158 | const struct cpumask *cpu_map) | |
6159 | { | |
dce840a0 PZ |
6160 | memset(d, 0, sizeof(*d)); |
6161 | ||
54ab4ff4 PZ |
6162 | if (__sdt_alloc(cpu_map)) |
6163 | return sa_sd_storage; | |
dce840a0 PZ |
6164 | d->sd = alloc_percpu(struct sched_domain *); |
6165 | if (!d->sd) | |
6166 | return sa_sd_storage; | |
2109b99e | 6167 | d->rd = alloc_rootdomain(); |
dce840a0 | 6168 | if (!d->rd) |
21d42ccf | 6169 | return sa_sd; |
2109b99e AH |
6170 | return sa_rootdomain; |
6171 | } | |
57d885fe | 6172 | |
dce840a0 PZ |
6173 | /* |
6174 | * NULL the sd_data elements we've used to build the sched_domain and | |
6175 | * sched_group structure so that the subsequent __free_domain_allocs() | |
6176 | * will not free the data we're using. | |
6177 | */ | |
6178 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
6179 | { | |
6180 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
6181 | |
6182 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
6183 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
6184 | ||
e3589f6c | 6185 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 6186 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c PZ |
6187 | |
6188 | if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref)) | |
9c3f75cb | 6189 | *per_cpu_ptr(sdd->sgp, cpu) = NULL; |
dce840a0 PZ |
6190 | } |
6191 | ||
2c402dc3 PZ |
6192 | #ifdef CONFIG_SCHED_SMT |
6193 | static const struct cpumask *cpu_smt_mask(int cpu) | |
7f4588f3 | 6194 | { |
2c402dc3 | 6195 | return topology_thread_cpumask(cpu); |
3bd65a80 | 6196 | } |
2c402dc3 | 6197 | #endif |
7f4588f3 | 6198 | |
d069b916 PZ |
6199 | /* |
6200 | * Topology list, bottom-up. | |
6201 | */ | |
2c402dc3 | 6202 | static struct sched_domain_topology_level default_topology[] = { |
d069b916 PZ |
6203 | #ifdef CONFIG_SCHED_SMT |
6204 | { sd_init_SIBLING, cpu_smt_mask, }, | |
01a08546 | 6205 | #endif |
1e9f28fa | 6206 | #ifdef CONFIG_SCHED_MC |
2c402dc3 | 6207 | { sd_init_MC, cpu_coregroup_mask, }, |
1e9f28fa | 6208 | #endif |
d069b916 PZ |
6209 | #ifdef CONFIG_SCHED_BOOK |
6210 | { sd_init_BOOK, cpu_book_mask, }, | |
6211 | #endif | |
6212 | { sd_init_CPU, cpu_cpu_mask, }, | |
6213 | #ifdef CONFIG_NUMA | |
e3589f6c | 6214 | { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, }, |
d069b916 | 6215 | { sd_init_ALLNODES, cpu_allnodes_mask, }, |
1da177e4 | 6216 | #endif |
eb7a74e6 PZ |
6217 | { NULL, }, |
6218 | }; | |
6219 | ||
6220 | static struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
6221 | ||
54ab4ff4 PZ |
6222 | static int __sdt_alloc(const struct cpumask *cpu_map) |
6223 | { | |
6224 | struct sched_domain_topology_level *tl; | |
6225 | int j; | |
6226 | ||
6227 | for (tl = sched_domain_topology; tl->init; tl++) { | |
6228 | struct sd_data *sdd = &tl->data; | |
6229 | ||
6230 | sdd->sd = alloc_percpu(struct sched_domain *); | |
6231 | if (!sdd->sd) | |
6232 | return -ENOMEM; | |
6233 | ||
6234 | sdd->sg = alloc_percpu(struct sched_group *); | |
6235 | if (!sdd->sg) | |
6236 | return -ENOMEM; | |
6237 | ||
9c3f75cb PZ |
6238 | sdd->sgp = alloc_percpu(struct sched_group_power *); |
6239 | if (!sdd->sgp) | |
6240 | return -ENOMEM; | |
6241 | ||
54ab4ff4 PZ |
6242 | for_each_cpu(j, cpu_map) { |
6243 | struct sched_domain *sd; | |
6244 | struct sched_group *sg; | |
9c3f75cb | 6245 | struct sched_group_power *sgp; |
54ab4ff4 PZ |
6246 | |
6247 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
6248 | GFP_KERNEL, cpu_to_node(j)); | |
6249 | if (!sd) | |
6250 | return -ENOMEM; | |
6251 | ||
6252 | *per_cpu_ptr(sdd->sd, j) = sd; | |
6253 | ||
6254 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6255 | GFP_KERNEL, cpu_to_node(j)); | |
6256 | if (!sg) | |
6257 | return -ENOMEM; | |
6258 | ||
6259 | *per_cpu_ptr(sdd->sg, j) = sg; | |
9c3f75cb PZ |
6260 | |
6261 | sgp = kzalloc_node(sizeof(struct sched_group_power), | |
6262 | GFP_KERNEL, cpu_to_node(j)); | |
6263 | if (!sgp) | |
6264 | return -ENOMEM; | |
6265 | ||
6266 | *per_cpu_ptr(sdd->sgp, j) = sgp; | |
54ab4ff4 PZ |
6267 | } |
6268 | } | |
6269 | ||
6270 | return 0; | |
6271 | } | |
6272 | ||
6273 | static void __sdt_free(const struct cpumask *cpu_map) | |
6274 | { | |
6275 | struct sched_domain_topology_level *tl; | |
6276 | int j; | |
6277 | ||
6278 | for (tl = sched_domain_topology; tl->init; tl++) { | |
6279 | struct sd_data *sdd = &tl->data; | |
6280 | ||
6281 | for_each_cpu(j, cpu_map) { | |
e3589f6c PZ |
6282 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j); |
6283 | if (sd && (sd->flags & SD_OVERLAP)) | |
6284 | free_sched_groups(sd->groups, 0); | |
feff8fa0 | 6285 | kfree(*per_cpu_ptr(sdd->sd, j)); |
54ab4ff4 | 6286 | kfree(*per_cpu_ptr(sdd->sg, j)); |
9c3f75cb | 6287 | kfree(*per_cpu_ptr(sdd->sgp, j)); |
54ab4ff4 PZ |
6288 | } |
6289 | free_percpu(sdd->sd); | |
6290 | free_percpu(sdd->sg); | |
9c3f75cb | 6291 | free_percpu(sdd->sgp); |
54ab4ff4 PZ |
6292 | } |
6293 | } | |
6294 | ||
2c402dc3 PZ |
6295 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
6296 | struct s_data *d, const struct cpumask *cpu_map, | |
d069b916 | 6297 | struct sched_domain_attr *attr, struct sched_domain *child, |
2c402dc3 PZ |
6298 | int cpu) |
6299 | { | |
54ab4ff4 | 6300 | struct sched_domain *sd = tl->init(tl, cpu); |
2c402dc3 | 6301 | if (!sd) |
d069b916 | 6302 | return child; |
2c402dc3 PZ |
6303 | |
6304 | set_domain_attribute(sd, attr); | |
6305 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); | |
60495e77 PZ |
6306 | if (child) { |
6307 | sd->level = child->level + 1; | |
6308 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 6309 | child->parent = sd; |
60495e77 | 6310 | } |
d069b916 | 6311 | sd->child = child; |
2c402dc3 PZ |
6312 | |
6313 | return sd; | |
6314 | } | |
6315 | ||
2109b99e AH |
6316 | /* |
6317 | * Build sched domains for a given set of cpus and attach the sched domains | |
6318 | * to the individual cpus | |
6319 | */ | |
dce840a0 PZ |
6320 | static int build_sched_domains(const struct cpumask *cpu_map, |
6321 | struct sched_domain_attr *attr) | |
2109b99e AH |
6322 | { |
6323 | enum s_alloc alloc_state = sa_none; | |
dce840a0 | 6324 | struct sched_domain *sd; |
2109b99e | 6325 | struct s_data d; |
822ff793 | 6326 | int i, ret = -ENOMEM; |
9c1cfda2 | 6327 | |
2109b99e AH |
6328 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6329 | if (alloc_state != sa_rootdomain) | |
6330 | goto error; | |
9c1cfda2 | 6331 | |
dce840a0 | 6332 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 6333 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
6334 | struct sched_domain_topology_level *tl; |
6335 | ||
3bd65a80 | 6336 | sd = NULL; |
e3589f6c | 6337 | for (tl = sched_domain_topology; tl->init; tl++) { |
2c402dc3 | 6338 | sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i); |
e3589f6c PZ |
6339 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
6340 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
6341 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
6342 | break; | |
e3589f6c | 6343 | } |
d274cb30 | 6344 | |
d069b916 PZ |
6345 | while (sd->child) |
6346 | sd = sd->child; | |
6347 | ||
21d42ccf | 6348 | *per_cpu_ptr(d.sd, i) = sd; |
dce840a0 PZ |
6349 | } |
6350 | ||
6351 | /* Build the groups for the domains */ | |
6352 | for_each_cpu(i, cpu_map) { | |
6353 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
6354 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
6355 | if (sd->flags & SD_OVERLAP) { |
6356 | if (build_overlap_sched_groups(sd, i)) | |
6357 | goto error; | |
6358 | } else { | |
6359 | if (build_sched_groups(sd, i)) | |
6360 | goto error; | |
6361 | } | |
1cf51902 | 6362 | } |
a06dadbe | 6363 | } |
9c1cfda2 | 6364 | |
1da177e4 | 6365 | /* Calculate CPU power for physical packages and nodes */ |
a9c9a9b6 PZ |
6366 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
6367 | if (!cpumask_test_cpu(i, cpu_map)) | |
6368 | continue; | |
9c1cfda2 | 6369 | |
dce840a0 PZ |
6370 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
6371 | claim_allocations(i, sd); | |
cd4ea6ae | 6372 | init_sched_groups_power(i, sd); |
dce840a0 | 6373 | } |
f712c0c7 | 6374 | } |
9c1cfda2 | 6375 | |
1da177e4 | 6376 | /* Attach the domains */ |
dce840a0 | 6377 | rcu_read_lock(); |
abcd083a | 6378 | for_each_cpu(i, cpu_map) { |
21d42ccf | 6379 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 6380 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 6381 | } |
dce840a0 | 6382 | rcu_read_unlock(); |
51888ca2 | 6383 | |
822ff793 | 6384 | ret = 0; |
51888ca2 | 6385 | error: |
2109b99e | 6386 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 6387 | return ret; |
1da177e4 | 6388 | } |
029190c5 | 6389 | |
acc3f5d7 | 6390 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 6391 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
6392 | static struct sched_domain_attr *dattr_cur; |
6393 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
6394 | |
6395 | /* | |
6396 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
6397 | * cpumask) fails, then fallback to a single sched domain, |
6398 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 6399 | */ |
4212823f | 6400 | static cpumask_var_t fallback_doms; |
029190c5 | 6401 | |
ee79d1bd HC |
6402 | /* |
6403 | * arch_update_cpu_topology lets virtualized architectures update the | |
6404 | * cpu core maps. It is supposed to return 1 if the topology changed | |
6405 | * or 0 if it stayed the same. | |
6406 | */ | |
6407 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 6408 | { |
ee79d1bd | 6409 | return 0; |
22e52b07 HC |
6410 | } |
6411 | ||
acc3f5d7 RR |
6412 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
6413 | { | |
6414 | int i; | |
6415 | cpumask_var_t *doms; | |
6416 | ||
6417 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
6418 | if (!doms) | |
6419 | return NULL; | |
6420 | for (i = 0; i < ndoms; i++) { | |
6421 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
6422 | free_sched_domains(doms, i); | |
6423 | return NULL; | |
6424 | } | |
6425 | } | |
6426 | return doms; | |
6427 | } | |
6428 | ||
6429 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
6430 | { | |
6431 | unsigned int i; | |
6432 | for (i = 0; i < ndoms; i++) | |
6433 | free_cpumask_var(doms[i]); | |
6434 | kfree(doms); | |
6435 | } | |
6436 | ||
1a20ff27 | 6437 | /* |
41a2d6cf | 6438 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
6439 | * For now this just excludes isolated cpus, but could be used to |
6440 | * exclude other special cases in the future. | |
1a20ff27 | 6441 | */ |
c4a8849a | 6442 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 6443 | { |
7378547f MM |
6444 | int err; |
6445 | ||
22e52b07 | 6446 | arch_update_cpu_topology(); |
029190c5 | 6447 | ndoms_cur = 1; |
acc3f5d7 | 6448 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 6449 | if (!doms_cur) |
acc3f5d7 RR |
6450 | doms_cur = &fallback_doms; |
6451 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 6452 | dattr_cur = NULL; |
dce840a0 | 6453 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 6454 | register_sched_domain_sysctl(); |
7378547f MM |
6455 | |
6456 | return err; | |
1a20ff27 DG |
6457 | } |
6458 | ||
1a20ff27 DG |
6459 | /* |
6460 | * Detach sched domains from a group of cpus specified in cpu_map | |
6461 | * These cpus will now be attached to the NULL domain | |
6462 | */ | |
96f874e2 | 6463 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
6464 | { |
6465 | int i; | |
6466 | ||
dce840a0 | 6467 | rcu_read_lock(); |
abcd083a | 6468 | for_each_cpu(i, cpu_map) |
57d885fe | 6469 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 6470 | rcu_read_unlock(); |
1a20ff27 DG |
6471 | } |
6472 | ||
1d3504fc HS |
6473 | /* handle null as "default" */ |
6474 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
6475 | struct sched_domain_attr *new, int idx_new) | |
6476 | { | |
6477 | struct sched_domain_attr tmp; | |
6478 | ||
6479 | /* fast path */ | |
6480 | if (!new && !cur) | |
6481 | return 1; | |
6482 | ||
6483 | tmp = SD_ATTR_INIT; | |
6484 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
6485 | new ? (new + idx_new) : &tmp, | |
6486 | sizeof(struct sched_domain_attr)); | |
6487 | } | |
6488 | ||
029190c5 PJ |
6489 | /* |
6490 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 6491 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
6492 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
6493 | * It destroys each deleted domain and builds each new domain. | |
6494 | * | |
acc3f5d7 | 6495 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
6496 | * The masks don't intersect (don't overlap.) We should setup one |
6497 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
6498 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
6499 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
6500 | * it as it is. | |
6501 | * | |
acc3f5d7 RR |
6502 | * The passed in 'doms_new' should be allocated using |
6503 | * alloc_sched_domains. This routine takes ownership of it and will | |
6504 | * free_sched_domains it when done with it. If the caller failed the | |
6505 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
6506 | * and partition_sched_domains() will fallback to the single partition | |
6507 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 6508 | * |
96f874e2 | 6509 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
6510 | * ndoms_new == 0 is a special case for destroying existing domains, |
6511 | * and it will not create the default domain. | |
dfb512ec | 6512 | * |
029190c5 PJ |
6513 | * Call with hotplug lock held |
6514 | */ | |
acc3f5d7 | 6515 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 6516 | struct sched_domain_attr *dattr_new) |
029190c5 | 6517 | { |
dfb512ec | 6518 | int i, j, n; |
d65bd5ec | 6519 | int new_topology; |
029190c5 | 6520 | |
712555ee | 6521 | mutex_lock(&sched_domains_mutex); |
a1835615 | 6522 | |
7378547f MM |
6523 | /* always unregister in case we don't destroy any domains */ |
6524 | unregister_sched_domain_sysctl(); | |
6525 | ||
d65bd5ec HC |
6526 | /* Let architecture update cpu core mappings. */ |
6527 | new_topology = arch_update_cpu_topology(); | |
6528 | ||
dfb512ec | 6529 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
6530 | |
6531 | /* Destroy deleted domains */ | |
6532 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 6533 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6534 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 6535 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
6536 | goto match1; |
6537 | } | |
6538 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 6539 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
6540 | match1: |
6541 | ; | |
6542 | } | |
6543 | ||
e761b772 MK |
6544 | if (doms_new == NULL) { |
6545 | ndoms_cur = 0; | |
acc3f5d7 | 6546 | doms_new = &fallback_doms; |
6ad4c188 | 6547 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 6548 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
6549 | } |
6550 | ||
029190c5 PJ |
6551 | /* Build new domains */ |
6552 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 6553 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 6554 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 6555 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
6556 | goto match2; |
6557 | } | |
6558 | /* no match - add a new doms_new */ | |
dce840a0 | 6559 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
6560 | match2: |
6561 | ; | |
6562 | } | |
6563 | ||
6564 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
6565 | if (doms_cur != &fallback_doms) |
6566 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 6567 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 6568 | doms_cur = doms_new; |
1d3504fc | 6569 | dattr_cur = dattr_new; |
029190c5 | 6570 | ndoms_cur = ndoms_new; |
7378547f MM |
6571 | |
6572 | register_sched_domain_sysctl(); | |
a1835615 | 6573 | |
712555ee | 6574 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
6575 | } |
6576 | ||
5c45bf27 | 6577 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c4a8849a | 6578 | static void reinit_sched_domains(void) |
5c45bf27 | 6579 | { |
95402b38 | 6580 | get_online_cpus(); |
dfb512ec MK |
6581 | |
6582 | /* Destroy domains first to force the rebuild */ | |
6583 | partition_sched_domains(0, NULL, NULL); | |
6584 | ||
e761b772 | 6585 | rebuild_sched_domains(); |
95402b38 | 6586 | put_online_cpus(); |
5c45bf27 SS |
6587 | } |
6588 | ||
6589 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
6590 | { | |
afb8a9b7 | 6591 | unsigned int level = 0; |
5c45bf27 | 6592 | |
afb8a9b7 GS |
6593 | if (sscanf(buf, "%u", &level) != 1) |
6594 | return -EINVAL; | |
6595 | ||
6596 | /* | |
6597 | * level is always be positive so don't check for | |
6598 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
6599 | * What happens on 0 or 1 byte write, | |
6600 | * need to check for count as well? | |
6601 | */ | |
6602 | ||
6603 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
6604 | return -EINVAL; |
6605 | ||
6606 | if (smt) | |
afb8a9b7 | 6607 | sched_smt_power_savings = level; |
5c45bf27 | 6608 | else |
afb8a9b7 | 6609 | sched_mc_power_savings = level; |
5c45bf27 | 6610 | |
c4a8849a | 6611 | reinit_sched_domains(); |
5c45bf27 | 6612 | |
c70f22d2 | 6613 | return count; |
5c45bf27 SS |
6614 | } |
6615 | ||
5c45bf27 | 6616 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 6617 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 6618 | struct sysdev_class_attribute *attr, |
f718cd4a | 6619 | char *page) |
5c45bf27 SS |
6620 | { |
6621 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
6622 | } | |
f718cd4a | 6623 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 6624 | struct sysdev_class_attribute *attr, |
48f24c4d | 6625 | const char *buf, size_t count) |
5c45bf27 SS |
6626 | { |
6627 | return sched_power_savings_store(buf, count, 0); | |
6628 | } | |
f718cd4a AK |
6629 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
6630 | sched_mc_power_savings_show, | |
6631 | sched_mc_power_savings_store); | |
5c45bf27 SS |
6632 | #endif |
6633 | ||
6634 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 6635 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 6636 | struct sysdev_class_attribute *attr, |
f718cd4a | 6637 | char *page) |
5c45bf27 SS |
6638 | { |
6639 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
6640 | } | |
f718cd4a | 6641 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 6642 | struct sysdev_class_attribute *attr, |
48f24c4d | 6643 | const char *buf, size_t count) |
5c45bf27 SS |
6644 | { |
6645 | return sched_power_savings_store(buf, count, 1); | |
6646 | } | |
f718cd4a AK |
6647 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
6648 | sched_smt_power_savings_show, | |
6707de00 AB |
6649 | sched_smt_power_savings_store); |
6650 | #endif | |
6651 | ||
39aac648 | 6652 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
6653 | { |
6654 | int err = 0; | |
6655 | ||
6656 | #ifdef CONFIG_SCHED_SMT | |
6657 | if (smt_capable()) | |
6658 | err = sysfs_create_file(&cls->kset.kobj, | |
6659 | &attr_sched_smt_power_savings.attr); | |
6660 | #endif | |
6661 | #ifdef CONFIG_SCHED_MC | |
6662 | if (!err && mc_capable()) | |
6663 | err = sysfs_create_file(&cls->kset.kobj, | |
6664 | &attr_sched_mc_power_savings.attr); | |
6665 | #endif | |
6666 | return err; | |
6667 | } | |
6d6bc0ad | 6668 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 6669 | |
1da177e4 | 6670 | /* |
3a101d05 TH |
6671 | * Update cpusets according to cpu_active mask. If cpusets are |
6672 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
6673 | * around partition_sched_domains(). | |
1da177e4 | 6674 | */ |
0b2e918a TH |
6675 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
6676 | void *hcpu) | |
e761b772 | 6677 | { |
3a101d05 | 6678 | switch (action & ~CPU_TASKS_FROZEN) { |
e761b772 | 6679 | case CPU_ONLINE: |
6ad4c188 | 6680 | case CPU_DOWN_FAILED: |
3a101d05 | 6681 | cpuset_update_active_cpus(); |
e761b772 | 6682 | return NOTIFY_OK; |
3a101d05 TH |
6683 | default: |
6684 | return NOTIFY_DONE; | |
6685 | } | |
6686 | } | |
e761b772 | 6687 | |
0b2e918a TH |
6688 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
6689 | void *hcpu) | |
3a101d05 TH |
6690 | { |
6691 | switch (action & ~CPU_TASKS_FROZEN) { | |
6692 | case CPU_DOWN_PREPARE: | |
6693 | cpuset_update_active_cpus(); | |
6694 | return NOTIFY_OK; | |
e761b772 MK |
6695 | default: |
6696 | return NOTIFY_DONE; | |
6697 | } | |
6698 | } | |
e761b772 | 6699 | |
1da177e4 LT |
6700 | void __init sched_init_smp(void) |
6701 | { | |
dcc30a35 RR |
6702 | cpumask_var_t non_isolated_cpus; |
6703 | ||
6704 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 6705 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 6706 | |
95402b38 | 6707 | get_online_cpus(); |
712555ee | 6708 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 6709 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
6710 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
6711 | if (cpumask_empty(non_isolated_cpus)) | |
6712 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 6713 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 6714 | put_online_cpus(); |
e761b772 | 6715 | |
3a101d05 TH |
6716 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
6717 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 MK |
6718 | |
6719 | /* RT runtime code needs to handle some hotplug events */ | |
6720 | hotcpu_notifier(update_runtime, 0); | |
6721 | ||
b328ca18 | 6722 | init_hrtick(); |
5c1e1767 NP |
6723 | |
6724 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 6725 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 6726 | BUG(); |
19978ca6 | 6727 | sched_init_granularity(); |
dcc30a35 | 6728 | free_cpumask_var(non_isolated_cpus); |
4212823f | 6729 | |
0e3900e6 | 6730 | init_sched_rt_class(); |
1da177e4 LT |
6731 | } |
6732 | #else | |
6733 | void __init sched_init_smp(void) | |
6734 | { | |
19978ca6 | 6735 | sched_init_granularity(); |
1da177e4 LT |
6736 | } |
6737 | #endif /* CONFIG_SMP */ | |
6738 | ||
cd1bb94b AB |
6739 | const_debug unsigned int sysctl_timer_migration = 1; |
6740 | ||
1da177e4 LT |
6741 | int in_sched_functions(unsigned long addr) |
6742 | { | |
1da177e4 LT |
6743 | return in_lock_functions(addr) || |
6744 | (addr >= (unsigned long)__sched_text_start | |
6745 | && addr < (unsigned long)__sched_text_end); | |
6746 | } | |
6747 | ||
029632fb PZ |
6748 | #ifdef CONFIG_CGROUP_SCHED |
6749 | struct task_group root_task_group; | |
052f1dc7 | 6750 | #endif |
6f505b16 | 6751 | |
029632fb | 6752 | DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask); |
6f505b16 | 6753 | |
1da177e4 LT |
6754 | void __init sched_init(void) |
6755 | { | |
dd41f596 | 6756 | int i, j; |
434d53b0 MT |
6757 | unsigned long alloc_size = 0, ptr; |
6758 | ||
6759 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
6760 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
6761 | #endif | |
6762 | #ifdef CONFIG_RT_GROUP_SCHED | |
6763 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 6764 | #endif |
df7c8e84 | 6765 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 6766 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 6767 | #endif |
434d53b0 | 6768 | if (alloc_size) { |
36b7b6d4 | 6769 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
6770 | |
6771 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 6772 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
6773 | ptr += nr_cpu_ids * sizeof(void **); |
6774 | ||
07e06b01 | 6775 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 6776 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 6777 | |
6d6bc0ad | 6778 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 6779 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6780 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
6781 | ptr += nr_cpu_ids * sizeof(void **); |
6782 | ||
07e06b01 | 6783 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
6784 | ptr += nr_cpu_ids * sizeof(void **); |
6785 | ||
6d6bc0ad | 6786 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
6787 | #ifdef CONFIG_CPUMASK_OFFSTACK |
6788 | for_each_possible_cpu(i) { | |
6789 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
6790 | ptr += cpumask_size(); | |
6791 | } | |
6792 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 6793 | } |
dd41f596 | 6794 | |
57d885fe GH |
6795 | #ifdef CONFIG_SMP |
6796 | init_defrootdomain(); | |
6797 | #endif | |
6798 | ||
d0b27fa7 PZ |
6799 | init_rt_bandwidth(&def_rt_bandwidth, |
6800 | global_rt_period(), global_rt_runtime()); | |
6801 | ||
6802 | #ifdef CONFIG_RT_GROUP_SCHED | |
07e06b01 | 6803 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 6804 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 6805 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 6806 | |
7c941438 | 6807 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
6808 | list_add(&root_task_group.list, &task_groups); |
6809 | INIT_LIST_HEAD(&root_task_group.children); | |
f4d6f6c2 | 6810 | INIT_LIST_HEAD(&root_task_group.siblings); |
5091faa4 | 6811 | autogroup_init(&init_task); |
54c707e9 | 6812 | |
7c941438 | 6813 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 6814 | |
54c707e9 GC |
6815 | #ifdef CONFIG_CGROUP_CPUACCT |
6816 | root_cpuacct.cpustat = &kernel_cpustat; | |
6817 | root_cpuacct.cpuusage = alloc_percpu(u64); | |
6818 | /* Too early, not expected to fail */ | |
6819 | BUG_ON(!root_cpuacct.cpuusage); | |
6820 | #endif | |
0a945022 | 6821 | for_each_possible_cpu(i) { |
70b97a7f | 6822 | struct rq *rq; |
1da177e4 LT |
6823 | |
6824 | rq = cpu_rq(i); | |
05fa785c | 6825 | raw_spin_lock_init(&rq->lock); |
7897986b | 6826 | rq->nr_running = 0; |
dce48a84 TG |
6827 | rq->calc_load_active = 0; |
6828 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 6829 | init_cfs_rq(&rq->cfs); |
6f505b16 | 6830 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 6831 | #ifdef CONFIG_FAIR_GROUP_SCHED |
029632fb | 6832 | root_task_group.shares = ROOT_TASK_GROUP_LOAD; |
6f505b16 | 6833 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 6834 | /* |
07e06b01 | 6835 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
6836 | * |
6837 | * In case of task-groups formed thr' the cgroup filesystem, it | |
6838 | * gets 100% of the cpu resources in the system. This overall | |
6839 | * system cpu resource is divided among the tasks of | |
07e06b01 | 6840 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
6841 | * based on each entity's (task or task-group's) weight |
6842 | * (se->load.weight). | |
6843 | * | |
07e06b01 | 6844 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
6845 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
6846 | * then A0's share of the cpu resource is: | |
6847 | * | |
0d905bca | 6848 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 6849 | * |
07e06b01 YZ |
6850 | * We achieve this by letting root_task_group's tasks sit |
6851 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 6852 | */ |
ab84d31e | 6853 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 6854 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
6855 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
6856 | ||
6857 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 6858 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 6859 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
07e06b01 | 6860 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 6861 | #endif |
1da177e4 | 6862 | |
dd41f596 IM |
6863 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
6864 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
6865 | |
6866 | rq->last_load_update_tick = jiffies; | |
6867 | ||
1da177e4 | 6868 | #ifdef CONFIG_SMP |
41c7ce9a | 6869 | rq->sd = NULL; |
57d885fe | 6870 | rq->rd = NULL; |
1399fa78 | 6871 | rq->cpu_power = SCHED_POWER_SCALE; |
3f029d3c | 6872 | rq->post_schedule = 0; |
1da177e4 | 6873 | rq->active_balance = 0; |
dd41f596 | 6874 | rq->next_balance = jiffies; |
1da177e4 | 6875 | rq->push_cpu = 0; |
0a2966b4 | 6876 | rq->cpu = i; |
1f11eb6a | 6877 | rq->online = 0; |
eae0c9df MG |
6878 | rq->idle_stamp = 0; |
6879 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
dc938520 | 6880 | rq_attach_root(rq, &def_root_domain); |
83cd4fe2 | 6881 | #ifdef CONFIG_NO_HZ |
1c792db7 | 6882 | rq->nohz_flags = 0; |
83cd4fe2 | 6883 | #endif |
1da177e4 | 6884 | #endif |
8f4d37ec | 6885 | init_rq_hrtick(rq); |
1da177e4 | 6886 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
6887 | } |
6888 | ||
2dd73a4f | 6889 | set_load_weight(&init_task); |
b50f60ce | 6890 | |
e107be36 AK |
6891 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
6892 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
6893 | #endif | |
6894 | ||
b50f60ce | 6895 | #ifdef CONFIG_RT_MUTEXES |
732375c6 | 6896 | plist_head_init(&init_task.pi_waiters); |
b50f60ce HC |
6897 | #endif |
6898 | ||
1da177e4 LT |
6899 | /* |
6900 | * The boot idle thread does lazy MMU switching as well: | |
6901 | */ | |
6902 | atomic_inc(&init_mm.mm_count); | |
6903 | enter_lazy_tlb(&init_mm, current); | |
6904 | ||
6905 | /* | |
6906 | * Make us the idle thread. Technically, schedule() should not be | |
6907 | * called from this thread, however somewhere below it might be, | |
6908 | * but because we are the idle thread, we just pick up running again | |
6909 | * when this runqueue becomes "idle". | |
6910 | */ | |
6911 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
6912 | |
6913 | calc_load_update = jiffies + LOAD_FREQ; | |
6914 | ||
dd41f596 IM |
6915 | /* |
6916 | * During early bootup we pretend to be a normal task: | |
6917 | */ | |
6918 | current->sched_class = &fair_sched_class; | |
6892b75e | 6919 | |
bf4d83f6 | 6920 | #ifdef CONFIG_SMP |
4cb98839 | 6921 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
bdddd296 RR |
6922 | /* May be allocated at isolcpus cmdline parse time */ |
6923 | if (cpu_isolated_map == NULL) | |
6924 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
029632fb PZ |
6925 | #endif |
6926 | init_sched_fair_class(); | |
6a7b3dc3 | 6927 | |
6892b75e | 6928 | scheduler_running = 1; |
1da177e4 LT |
6929 | } |
6930 | ||
d902db1e | 6931 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
6932 | static inline int preempt_count_equals(int preempt_offset) |
6933 | { | |
234da7bc | 6934 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 6935 | |
4ba8216c | 6936 | return (nested == preempt_offset); |
e4aafea2 FW |
6937 | } |
6938 | ||
d894837f | 6939 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 6940 | { |
1da177e4 LT |
6941 | static unsigned long prev_jiffy; /* ratelimiting */ |
6942 | ||
b3fbab05 | 6943 | rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */ |
e4aafea2 FW |
6944 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
6945 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
6946 | return; |
6947 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
6948 | return; | |
6949 | prev_jiffy = jiffies; | |
6950 | ||
3df0fc5b PZ |
6951 | printk(KERN_ERR |
6952 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
6953 | file, line); | |
6954 | printk(KERN_ERR | |
6955 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
6956 | in_atomic(), irqs_disabled(), | |
6957 | current->pid, current->comm); | |
aef745fc IM |
6958 | |
6959 | debug_show_held_locks(current); | |
6960 | if (irqs_disabled()) | |
6961 | print_irqtrace_events(current); | |
6962 | dump_stack(); | |
1da177e4 LT |
6963 | } |
6964 | EXPORT_SYMBOL(__might_sleep); | |
6965 | #endif | |
6966 | ||
6967 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
6968 | static void normalize_task(struct rq *rq, struct task_struct *p) |
6969 | { | |
da7a735e PZ |
6970 | const struct sched_class *prev_class = p->sched_class; |
6971 | int old_prio = p->prio; | |
3a5e4dc1 | 6972 | int on_rq; |
3e51f33f | 6973 | |
fd2f4419 | 6974 | on_rq = p->on_rq; |
3a5e4dc1 AK |
6975 | if (on_rq) |
6976 | deactivate_task(rq, p, 0); | |
6977 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
6978 | if (on_rq) { | |
6979 | activate_task(rq, p, 0); | |
6980 | resched_task(rq->curr); | |
6981 | } | |
da7a735e PZ |
6982 | |
6983 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
6984 | } |
6985 | ||
1da177e4 LT |
6986 | void normalize_rt_tasks(void) |
6987 | { | |
a0f98a1c | 6988 | struct task_struct *g, *p; |
1da177e4 | 6989 | unsigned long flags; |
70b97a7f | 6990 | struct rq *rq; |
1da177e4 | 6991 | |
4cf5d77a | 6992 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 6993 | do_each_thread(g, p) { |
178be793 IM |
6994 | /* |
6995 | * Only normalize user tasks: | |
6996 | */ | |
6997 | if (!p->mm) | |
6998 | continue; | |
6999 | ||
6cfb0d5d | 7000 | p->se.exec_start = 0; |
6cfb0d5d | 7001 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7002 | p->se.statistics.wait_start = 0; |
7003 | p->se.statistics.sleep_start = 0; | |
7004 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7005 | #endif |
dd41f596 IM |
7006 | |
7007 | if (!rt_task(p)) { | |
7008 | /* | |
7009 | * Renice negative nice level userspace | |
7010 | * tasks back to 0: | |
7011 | */ | |
7012 | if (TASK_NICE(p) < 0 && p->mm) | |
7013 | set_user_nice(p, 0); | |
1da177e4 | 7014 | continue; |
dd41f596 | 7015 | } |
1da177e4 | 7016 | |
1d615482 | 7017 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7018 | rq = __task_rq_lock(p); |
1da177e4 | 7019 | |
178be793 | 7020 | normalize_task(rq, p); |
3a5e4dc1 | 7021 | |
b29739f9 | 7022 | __task_rq_unlock(rq); |
1d615482 | 7023 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7024 | } while_each_thread(g, p); |
7025 | ||
4cf5d77a | 7026 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7027 | } |
7028 | ||
7029 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7030 | |
67fc4e0c | 7031 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7032 | /* |
67fc4e0c | 7033 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7034 | * |
7035 | * They can only be called when the whole system has been | |
7036 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7037 | * activity can take place. Using them for anything else would | |
7038 | * be a serious bug, and as a result, they aren't even visible | |
7039 | * under any other configuration. | |
7040 | */ | |
7041 | ||
7042 | /** | |
7043 | * curr_task - return the current task for a given cpu. | |
7044 | * @cpu: the processor in question. | |
7045 | * | |
7046 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7047 | */ | |
36c8b586 | 7048 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7049 | { |
7050 | return cpu_curr(cpu); | |
7051 | } | |
7052 | ||
67fc4e0c JW |
7053 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7054 | ||
7055 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7056 | /** |
7057 | * set_curr_task - set the current task for a given cpu. | |
7058 | * @cpu: the processor in question. | |
7059 | * @p: the task pointer to set. | |
7060 | * | |
7061 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7062 | * are serviced on a separate stack. It allows the architecture to switch the |
7063 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7064 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7065 | * and caller must save the original value of the current task (see | |
7066 | * curr_task() above) and restore that value before reenabling interrupts and | |
7067 | * re-starting the system. | |
7068 | * | |
7069 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7070 | */ | |
36c8b586 | 7071 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7072 | { |
7073 | cpu_curr(cpu) = p; | |
7074 | } | |
7075 | ||
7076 | #endif | |
29f59db3 | 7077 | |
052f1dc7 | 7078 | #ifdef CONFIG_RT_GROUP_SCHED |
6d6bc0ad | 7079 | #else /* !CONFIG_RT_GROUP_SCHED */ |
6d6bc0ad | 7080 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 7081 | |
7c941438 | 7082 | #ifdef CONFIG_CGROUP_SCHED |
029632fb PZ |
7083 | /* task_group_lock serializes the addition/removal of task groups */ |
7084 | static DEFINE_SPINLOCK(task_group_lock); | |
7085 | ||
bccbe08a PZ |
7086 | static void free_sched_group(struct task_group *tg) |
7087 | { | |
7088 | free_fair_sched_group(tg); | |
7089 | free_rt_sched_group(tg); | |
e9aa1dd1 | 7090 | autogroup_free(tg); |
bccbe08a PZ |
7091 | kfree(tg); |
7092 | } | |
7093 | ||
7094 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 7095 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
7096 | { |
7097 | struct task_group *tg; | |
7098 | unsigned long flags; | |
bccbe08a PZ |
7099 | |
7100 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
7101 | if (!tg) | |
7102 | return ERR_PTR(-ENOMEM); | |
7103 | ||
ec7dc8ac | 7104 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
7105 | goto err; |
7106 | ||
ec7dc8ac | 7107 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
7108 | goto err; |
7109 | ||
8ed36996 | 7110 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 7111 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
7112 | |
7113 | WARN_ON(!parent); /* root should already exist */ | |
7114 | ||
7115 | tg->parent = parent; | |
f473aa5e | 7116 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 7117 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 7118 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 7119 | |
9b5b7751 | 7120 | return tg; |
29f59db3 SV |
7121 | |
7122 | err: | |
6f505b16 | 7123 | free_sched_group(tg); |
29f59db3 SV |
7124 | return ERR_PTR(-ENOMEM); |
7125 | } | |
7126 | ||
9b5b7751 | 7127 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 7128 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 7129 | { |
29f59db3 | 7130 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 7131 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
7132 | } |
7133 | ||
9b5b7751 | 7134 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 7135 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 7136 | { |
8ed36996 | 7137 | unsigned long flags; |
9b5b7751 | 7138 | int i; |
29f59db3 | 7139 | |
3d4b47b4 PZ |
7140 | /* end participation in shares distribution */ |
7141 | for_each_possible_cpu(i) | |
bccbe08a | 7142 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
7143 | |
7144 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 7145 | list_del_rcu(&tg->list); |
f473aa5e | 7146 | list_del_rcu(&tg->siblings); |
8ed36996 | 7147 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 7148 | |
9b5b7751 | 7149 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 7150 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
7151 | } |
7152 | ||
9b5b7751 | 7153 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
7154 | * The caller of this function should have put the task in its new group |
7155 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
7156 | * reflect its new group. | |
9b5b7751 SV |
7157 | */ |
7158 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
7159 | { |
7160 | int on_rq, running; | |
7161 | unsigned long flags; | |
7162 | struct rq *rq; | |
7163 | ||
7164 | rq = task_rq_lock(tsk, &flags); | |
7165 | ||
051a1d1a | 7166 | running = task_current(rq, tsk); |
fd2f4419 | 7167 | on_rq = tsk->on_rq; |
29f59db3 | 7168 | |
0e1f3483 | 7169 | if (on_rq) |
29f59db3 | 7170 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
7171 | if (unlikely(running)) |
7172 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 7173 | |
810b3817 | 7174 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
7175 | if (tsk->sched_class->task_move_group) |
7176 | tsk->sched_class->task_move_group(tsk, on_rq); | |
7177 | else | |
810b3817 | 7178 | #endif |
b2b5ce02 | 7179 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 7180 | |
0e1f3483 HS |
7181 | if (unlikely(running)) |
7182 | tsk->sched_class->set_curr_task(rq); | |
7183 | if (on_rq) | |
371fd7e7 | 7184 | enqueue_task(rq, tsk, 0); |
29f59db3 | 7185 | |
0122ec5b | 7186 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 7187 | } |
7c941438 | 7188 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 7189 | |
052f1dc7 | 7190 | #ifdef CONFIG_FAIR_GROUP_SCHED |
052f1dc7 | 7191 | #endif |
5cb350ba | 7192 | |
a790de99 | 7193 | #if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH) |
9f0c1e56 PZ |
7194 | static unsigned long to_ratio(u64 period, u64 runtime) |
7195 | { | |
7196 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 7197 | return 1ULL << 20; |
9f0c1e56 | 7198 | |
9a7e0b18 | 7199 | return div64_u64(runtime << 20, period); |
9f0c1e56 | 7200 | } |
a790de99 PT |
7201 | #endif |
7202 | ||
7203 | #ifdef CONFIG_RT_GROUP_SCHED | |
7204 | /* | |
7205 | * Ensure that the real time constraints are schedulable. | |
7206 | */ | |
7207 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 7208 | |
9a7e0b18 PZ |
7209 | /* Must be called with tasklist_lock held */ |
7210 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 7211 | { |
9a7e0b18 | 7212 | struct task_struct *g, *p; |
b40b2e8e | 7213 | |
9a7e0b18 | 7214 | do_each_thread(g, p) { |
029632fb | 7215 | if (rt_task(p) && task_rq(p)->rt.tg == tg) |
9a7e0b18 PZ |
7216 | return 1; |
7217 | } while_each_thread(g, p); | |
b40b2e8e | 7218 | |
9a7e0b18 PZ |
7219 | return 0; |
7220 | } | |
b40b2e8e | 7221 | |
9a7e0b18 PZ |
7222 | struct rt_schedulable_data { |
7223 | struct task_group *tg; | |
7224 | u64 rt_period; | |
7225 | u64 rt_runtime; | |
7226 | }; | |
b40b2e8e | 7227 | |
a790de99 | 7228 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
7229 | { |
7230 | struct rt_schedulable_data *d = data; | |
7231 | struct task_group *child; | |
7232 | unsigned long total, sum = 0; | |
7233 | u64 period, runtime; | |
b40b2e8e | 7234 | |
9a7e0b18 PZ |
7235 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
7236 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 7237 | |
9a7e0b18 PZ |
7238 | if (tg == d->tg) { |
7239 | period = d->rt_period; | |
7240 | runtime = d->rt_runtime; | |
b40b2e8e | 7241 | } |
b40b2e8e | 7242 | |
4653f803 PZ |
7243 | /* |
7244 | * Cannot have more runtime than the period. | |
7245 | */ | |
7246 | if (runtime > period && runtime != RUNTIME_INF) | |
7247 | return -EINVAL; | |
6f505b16 | 7248 | |
4653f803 PZ |
7249 | /* |
7250 | * Ensure we don't starve existing RT tasks. | |
7251 | */ | |
9a7e0b18 PZ |
7252 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
7253 | return -EBUSY; | |
6f505b16 | 7254 | |
9a7e0b18 | 7255 | total = to_ratio(period, runtime); |
6f505b16 | 7256 | |
4653f803 PZ |
7257 | /* |
7258 | * Nobody can have more than the global setting allows. | |
7259 | */ | |
7260 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
7261 | return -EINVAL; | |
6f505b16 | 7262 | |
4653f803 PZ |
7263 | /* |
7264 | * The sum of our children's runtime should not exceed our own. | |
7265 | */ | |
9a7e0b18 PZ |
7266 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
7267 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
7268 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 7269 | |
9a7e0b18 PZ |
7270 | if (child == d->tg) { |
7271 | period = d->rt_period; | |
7272 | runtime = d->rt_runtime; | |
7273 | } | |
6f505b16 | 7274 | |
9a7e0b18 | 7275 | sum += to_ratio(period, runtime); |
9f0c1e56 | 7276 | } |
6f505b16 | 7277 | |
9a7e0b18 PZ |
7278 | if (sum > total) |
7279 | return -EINVAL; | |
7280 | ||
7281 | return 0; | |
6f505b16 PZ |
7282 | } |
7283 | ||
9a7e0b18 | 7284 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 7285 | { |
8277434e PT |
7286 | int ret; |
7287 | ||
9a7e0b18 PZ |
7288 | struct rt_schedulable_data data = { |
7289 | .tg = tg, | |
7290 | .rt_period = period, | |
7291 | .rt_runtime = runtime, | |
7292 | }; | |
7293 | ||
8277434e PT |
7294 | rcu_read_lock(); |
7295 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
7296 | rcu_read_unlock(); | |
7297 | ||
7298 | return ret; | |
521f1a24 DG |
7299 | } |
7300 | ||
ab84d31e | 7301 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 7302 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 7303 | { |
ac086bc2 | 7304 | int i, err = 0; |
9f0c1e56 | 7305 | |
9f0c1e56 | 7306 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 7307 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
7308 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
7309 | if (err) | |
9f0c1e56 | 7310 | goto unlock; |
ac086bc2 | 7311 | |
0986b11b | 7312 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
7313 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
7314 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
7315 | |
7316 | for_each_possible_cpu(i) { | |
7317 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
7318 | ||
0986b11b | 7319 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7320 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 7321 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7322 | } |
0986b11b | 7323 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 7324 | unlock: |
521f1a24 | 7325 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
7326 | mutex_unlock(&rt_constraints_mutex); |
7327 | ||
7328 | return err; | |
6f505b16 PZ |
7329 | } |
7330 | ||
d0b27fa7 PZ |
7331 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
7332 | { | |
7333 | u64 rt_runtime, rt_period; | |
7334 | ||
7335 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7336 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
7337 | if (rt_runtime_us < 0) | |
7338 | rt_runtime = RUNTIME_INF; | |
7339 | ||
ab84d31e | 7340 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7341 | } |
7342 | ||
9f0c1e56 PZ |
7343 | long sched_group_rt_runtime(struct task_group *tg) |
7344 | { | |
7345 | u64 rt_runtime_us; | |
7346 | ||
d0b27fa7 | 7347 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
7348 | return -1; |
7349 | ||
d0b27fa7 | 7350 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
7351 | do_div(rt_runtime_us, NSEC_PER_USEC); |
7352 | return rt_runtime_us; | |
7353 | } | |
d0b27fa7 PZ |
7354 | |
7355 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
7356 | { | |
7357 | u64 rt_runtime, rt_period; | |
7358 | ||
7359 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
7360 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
7361 | ||
619b0488 R |
7362 | if (rt_period == 0) |
7363 | return -EINVAL; | |
7364 | ||
ab84d31e | 7365 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7366 | } |
7367 | ||
7368 | long sched_group_rt_period(struct task_group *tg) | |
7369 | { | |
7370 | u64 rt_period_us; | |
7371 | ||
7372 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7373 | do_div(rt_period_us, NSEC_PER_USEC); | |
7374 | return rt_period_us; | |
7375 | } | |
7376 | ||
7377 | static int sched_rt_global_constraints(void) | |
7378 | { | |
4653f803 | 7379 | u64 runtime, period; |
d0b27fa7 PZ |
7380 | int ret = 0; |
7381 | ||
ec5d4989 HS |
7382 | if (sysctl_sched_rt_period <= 0) |
7383 | return -EINVAL; | |
7384 | ||
4653f803 PZ |
7385 | runtime = global_rt_runtime(); |
7386 | period = global_rt_period(); | |
7387 | ||
7388 | /* | |
7389 | * Sanity check on the sysctl variables. | |
7390 | */ | |
7391 | if (runtime > period && runtime != RUNTIME_INF) | |
7392 | return -EINVAL; | |
10b612f4 | 7393 | |
d0b27fa7 | 7394 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 7395 | read_lock(&tasklist_lock); |
4653f803 | 7396 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 7397 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
7398 | mutex_unlock(&rt_constraints_mutex); |
7399 | ||
7400 | return ret; | |
7401 | } | |
54e99124 DG |
7402 | |
7403 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
7404 | { | |
7405 | /* Don't accept realtime tasks when there is no way for them to run */ | |
7406 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
7407 | return 0; | |
7408 | ||
7409 | return 1; | |
7410 | } | |
7411 | ||
6d6bc0ad | 7412 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7413 | static int sched_rt_global_constraints(void) |
7414 | { | |
ac086bc2 PZ |
7415 | unsigned long flags; |
7416 | int i; | |
7417 | ||
ec5d4989 HS |
7418 | if (sysctl_sched_rt_period <= 0) |
7419 | return -EINVAL; | |
7420 | ||
60aa605d PZ |
7421 | /* |
7422 | * There's always some RT tasks in the root group | |
7423 | * -- migration, kstopmachine etc.. | |
7424 | */ | |
7425 | if (sysctl_sched_rt_runtime == 0) | |
7426 | return -EBUSY; | |
7427 | ||
0986b11b | 7428 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
7429 | for_each_possible_cpu(i) { |
7430 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
7431 | ||
0986b11b | 7432 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7433 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 7434 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7435 | } |
0986b11b | 7436 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 7437 | |
d0b27fa7 PZ |
7438 | return 0; |
7439 | } | |
6d6bc0ad | 7440 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7441 | |
7442 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 7443 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
7444 | loff_t *ppos) |
7445 | { | |
7446 | int ret; | |
7447 | int old_period, old_runtime; | |
7448 | static DEFINE_MUTEX(mutex); | |
7449 | ||
7450 | mutex_lock(&mutex); | |
7451 | old_period = sysctl_sched_rt_period; | |
7452 | old_runtime = sysctl_sched_rt_runtime; | |
7453 | ||
8d65af78 | 7454 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
7455 | |
7456 | if (!ret && write) { | |
7457 | ret = sched_rt_global_constraints(); | |
7458 | if (ret) { | |
7459 | sysctl_sched_rt_period = old_period; | |
7460 | sysctl_sched_rt_runtime = old_runtime; | |
7461 | } else { | |
7462 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
7463 | def_rt_bandwidth.rt_period = | |
7464 | ns_to_ktime(global_rt_period()); | |
7465 | } | |
7466 | } | |
7467 | mutex_unlock(&mutex); | |
7468 | ||
7469 | return ret; | |
7470 | } | |
68318b8e | 7471 | |
052f1dc7 | 7472 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
7473 | |
7474 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 7475 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 7476 | { |
2b01dfe3 PM |
7477 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
7478 | struct task_group, css); | |
68318b8e SV |
7479 | } |
7480 | ||
7481 | static struct cgroup_subsys_state * | |
2b01dfe3 | 7482 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 7483 | { |
ec7dc8ac | 7484 | struct task_group *tg, *parent; |
68318b8e | 7485 | |
2b01dfe3 | 7486 | if (!cgrp->parent) { |
68318b8e | 7487 | /* This is early initialization for the top cgroup */ |
07e06b01 | 7488 | return &root_task_group.css; |
68318b8e SV |
7489 | } |
7490 | ||
ec7dc8ac DG |
7491 | parent = cgroup_tg(cgrp->parent); |
7492 | tg = sched_create_group(parent); | |
68318b8e SV |
7493 | if (IS_ERR(tg)) |
7494 | return ERR_PTR(-ENOMEM); | |
7495 | ||
68318b8e SV |
7496 | return &tg->css; |
7497 | } | |
7498 | ||
41a2d6cf IM |
7499 | static void |
7500 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 7501 | { |
2b01dfe3 | 7502 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
7503 | |
7504 | sched_destroy_group(tg); | |
7505 | } | |
7506 | ||
41a2d6cf | 7507 | static int |
be367d09 | 7508 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 7509 | { |
b68aa230 | 7510 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 7511 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
7512 | return -EINVAL; |
7513 | #else | |
68318b8e SV |
7514 | /* We don't support RT-tasks being in separate groups */ |
7515 | if (tsk->sched_class != &fair_sched_class) | |
7516 | return -EINVAL; | |
b68aa230 | 7517 | #endif |
be367d09 BB |
7518 | return 0; |
7519 | } | |
68318b8e | 7520 | |
68318b8e | 7521 | static void |
f780bdb7 | 7522 | cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e SV |
7523 | { |
7524 | sched_move_task(tsk); | |
7525 | } | |
7526 | ||
068c5cc5 | 7527 | static void |
d41d5a01 PZ |
7528 | cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, |
7529 | struct cgroup *old_cgrp, struct task_struct *task) | |
068c5cc5 PZ |
7530 | { |
7531 | /* | |
7532 | * cgroup_exit() is called in the copy_process() failure path. | |
7533 | * Ignore this case since the task hasn't ran yet, this avoids | |
7534 | * trying to poke a half freed task state from generic code. | |
7535 | */ | |
7536 | if (!(task->flags & PF_EXITING)) | |
7537 | return; | |
7538 | ||
7539 | sched_move_task(task); | |
7540 | } | |
7541 | ||
052f1dc7 | 7542 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 7543 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 7544 | u64 shareval) |
68318b8e | 7545 | { |
c8b28116 | 7546 | return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval)); |
68318b8e SV |
7547 | } |
7548 | ||
f4c753b7 | 7549 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 7550 | { |
2b01dfe3 | 7551 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e | 7552 | |
c8b28116 | 7553 | return (u64) scale_load_down(tg->shares); |
68318b8e | 7554 | } |
ab84d31e PT |
7555 | |
7556 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
7557 | static DEFINE_MUTEX(cfs_constraints_mutex); |
7558 | ||
ab84d31e PT |
7559 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
7560 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
7561 | ||
a790de99 PT |
7562 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
7563 | ||
ab84d31e PT |
7564 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
7565 | { | |
56f570e5 | 7566 | int i, ret = 0, runtime_enabled, runtime_was_enabled; |
029632fb | 7567 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
ab84d31e PT |
7568 | |
7569 | if (tg == &root_task_group) | |
7570 | return -EINVAL; | |
7571 | ||
7572 | /* | |
7573 | * Ensure we have at some amount of bandwidth every period. This is | |
7574 | * to prevent reaching a state of large arrears when throttled via | |
7575 | * entity_tick() resulting in prolonged exit starvation. | |
7576 | */ | |
7577 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
7578 | return -EINVAL; | |
7579 | ||
7580 | /* | |
7581 | * Likewise, bound things on the otherside by preventing insane quota | |
7582 | * periods. This also allows us to normalize in computing quota | |
7583 | * feasibility. | |
7584 | */ | |
7585 | if (period > max_cfs_quota_period) | |
7586 | return -EINVAL; | |
7587 | ||
a790de99 PT |
7588 | mutex_lock(&cfs_constraints_mutex); |
7589 | ret = __cfs_schedulable(tg, period, quota); | |
7590 | if (ret) | |
7591 | goto out_unlock; | |
7592 | ||
58088ad0 | 7593 | runtime_enabled = quota != RUNTIME_INF; |
56f570e5 PT |
7594 | runtime_was_enabled = cfs_b->quota != RUNTIME_INF; |
7595 | account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled); | |
ab84d31e PT |
7596 | raw_spin_lock_irq(&cfs_b->lock); |
7597 | cfs_b->period = ns_to_ktime(period); | |
7598 | cfs_b->quota = quota; | |
58088ad0 | 7599 | |
a9cf55b2 | 7600 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
7601 | /* restart the period timer (if active) to handle new period expiry */ |
7602 | if (runtime_enabled && cfs_b->timer_active) { | |
7603 | /* force a reprogram */ | |
7604 | cfs_b->timer_active = 0; | |
7605 | __start_cfs_bandwidth(cfs_b); | |
7606 | } | |
ab84d31e PT |
7607 | raw_spin_unlock_irq(&cfs_b->lock); |
7608 | ||
7609 | for_each_possible_cpu(i) { | |
7610 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; | |
029632fb | 7611 | struct rq *rq = cfs_rq->rq; |
ab84d31e PT |
7612 | |
7613 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 7614 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 7615 | cfs_rq->runtime_remaining = 0; |
671fd9da | 7616 | |
029632fb | 7617 | if (cfs_rq->throttled) |
671fd9da | 7618 | unthrottle_cfs_rq(cfs_rq); |
ab84d31e PT |
7619 | raw_spin_unlock_irq(&rq->lock); |
7620 | } | |
a790de99 PT |
7621 | out_unlock: |
7622 | mutex_unlock(&cfs_constraints_mutex); | |
ab84d31e | 7623 | |
a790de99 | 7624 | return ret; |
ab84d31e PT |
7625 | } |
7626 | ||
7627 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
7628 | { | |
7629 | u64 quota, period; | |
7630 | ||
029632fb | 7631 | period = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7632 | if (cfs_quota_us < 0) |
7633 | quota = RUNTIME_INF; | |
7634 | else | |
7635 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
7636 | ||
7637 | return tg_set_cfs_bandwidth(tg, period, quota); | |
7638 | } | |
7639 | ||
7640 | long tg_get_cfs_quota(struct task_group *tg) | |
7641 | { | |
7642 | u64 quota_us; | |
7643 | ||
029632fb | 7644 | if (tg->cfs_bandwidth.quota == RUNTIME_INF) |
ab84d31e PT |
7645 | return -1; |
7646 | ||
029632fb | 7647 | quota_us = tg->cfs_bandwidth.quota; |
ab84d31e PT |
7648 | do_div(quota_us, NSEC_PER_USEC); |
7649 | ||
7650 | return quota_us; | |
7651 | } | |
7652 | ||
7653 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
7654 | { | |
7655 | u64 quota, period; | |
7656 | ||
7657 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
029632fb | 7658 | quota = tg->cfs_bandwidth.quota; |
ab84d31e PT |
7659 | |
7660 | if (period <= 0) | |
7661 | return -EINVAL; | |
7662 | ||
7663 | return tg_set_cfs_bandwidth(tg, period, quota); | |
7664 | } | |
7665 | ||
7666 | long tg_get_cfs_period(struct task_group *tg) | |
7667 | { | |
7668 | u64 cfs_period_us; | |
7669 | ||
029632fb | 7670 | cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7671 | do_div(cfs_period_us, NSEC_PER_USEC); |
7672 | ||
7673 | return cfs_period_us; | |
7674 | } | |
7675 | ||
7676 | static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft) | |
7677 | { | |
7678 | return tg_get_cfs_quota(cgroup_tg(cgrp)); | |
7679 | } | |
7680 | ||
7681 | static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype, | |
7682 | s64 cfs_quota_us) | |
7683 | { | |
7684 | return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us); | |
7685 | } | |
7686 | ||
7687 | static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft) | |
7688 | { | |
7689 | return tg_get_cfs_period(cgroup_tg(cgrp)); | |
7690 | } | |
7691 | ||
7692 | static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype, | |
7693 | u64 cfs_period_us) | |
7694 | { | |
7695 | return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us); | |
7696 | } | |
7697 | ||
a790de99 PT |
7698 | struct cfs_schedulable_data { |
7699 | struct task_group *tg; | |
7700 | u64 period, quota; | |
7701 | }; | |
7702 | ||
7703 | /* | |
7704 | * normalize group quota/period to be quota/max_period | |
7705 | * note: units are usecs | |
7706 | */ | |
7707 | static u64 normalize_cfs_quota(struct task_group *tg, | |
7708 | struct cfs_schedulable_data *d) | |
7709 | { | |
7710 | u64 quota, period; | |
7711 | ||
7712 | if (tg == d->tg) { | |
7713 | period = d->period; | |
7714 | quota = d->quota; | |
7715 | } else { | |
7716 | period = tg_get_cfs_period(tg); | |
7717 | quota = tg_get_cfs_quota(tg); | |
7718 | } | |
7719 | ||
7720 | /* note: these should typically be equivalent */ | |
7721 | if (quota == RUNTIME_INF || quota == -1) | |
7722 | return RUNTIME_INF; | |
7723 | ||
7724 | return to_ratio(period, quota); | |
7725 | } | |
7726 | ||
7727 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
7728 | { | |
7729 | struct cfs_schedulable_data *d = data; | |
029632fb | 7730 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
a790de99 PT |
7731 | s64 quota = 0, parent_quota = -1; |
7732 | ||
7733 | if (!tg->parent) { | |
7734 | quota = RUNTIME_INF; | |
7735 | } else { | |
029632fb | 7736 | struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth; |
a790de99 PT |
7737 | |
7738 | quota = normalize_cfs_quota(tg, d); | |
7739 | parent_quota = parent_b->hierarchal_quota; | |
7740 | ||
7741 | /* | |
7742 | * ensure max(child_quota) <= parent_quota, inherit when no | |
7743 | * limit is set | |
7744 | */ | |
7745 | if (quota == RUNTIME_INF) | |
7746 | quota = parent_quota; | |
7747 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
7748 | return -EINVAL; | |
7749 | } | |
7750 | cfs_b->hierarchal_quota = quota; | |
7751 | ||
7752 | return 0; | |
7753 | } | |
7754 | ||
7755 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
7756 | { | |
8277434e | 7757 | int ret; |
a790de99 PT |
7758 | struct cfs_schedulable_data data = { |
7759 | .tg = tg, | |
7760 | .period = period, | |
7761 | .quota = quota, | |
7762 | }; | |
7763 | ||
7764 | if (quota != RUNTIME_INF) { | |
7765 | do_div(data.period, NSEC_PER_USEC); | |
7766 | do_div(data.quota, NSEC_PER_USEC); | |
7767 | } | |
7768 | ||
8277434e PT |
7769 | rcu_read_lock(); |
7770 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
7771 | rcu_read_unlock(); | |
7772 | ||
7773 | return ret; | |
a790de99 | 7774 | } |
e8da1b18 NR |
7775 | |
7776 | static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
7777 | struct cgroup_map_cb *cb) | |
7778 | { | |
7779 | struct task_group *tg = cgroup_tg(cgrp); | |
029632fb | 7780 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
e8da1b18 NR |
7781 | |
7782 | cb->fill(cb, "nr_periods", cfs_b->nr_periods); | |
7783 | cb->fill(cb, "nr_throttled", cfs_b->nr_throttled); | |
7784 | cb->fill(cb, "throttled_time", cfs_b->throttled_time); | |
7785 | ||
7786 | return 0; | |
7787 | } | |
ab84d31e | 7788 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 7789 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 7790 | |
052f1dc7 | 7791 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 7792 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 7793 | s64 val) |
6f505b16 | 7794 | { |
06ecb27c | 7795 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
7796 | } |
7797 | ||
06ecb27c | 7798 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 7799 | { |
06ecb27c | 7800 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 7801 | } |
d0b27fa7 PZ |
7802 | |
7803 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
7804 | u64 rt_period_us) | |
7805 | { | |
7806 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
7807 | } | |
7808 | ||
7809 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
7810 | { | |
7811 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
7812 | } | |
6d6bc0ad | 7813 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 7814 | |
fe5c7cc2 | 7815 | static struct cftype cpu_files[] = { |
052f1dc7 | 7816 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
7817 | { |
7818 | .name = "shares", | |
f4c753b7 PM |
7819 | .read_u64 = cpu_shares_read_u64, |
7820 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 7821 | }, |
052f1dc7 | 7822 | #endif |
ab84d31e PT |
7823 | #ifdef CONFIG_CFS_BANDWIDTH |
7824 | { | |
7825 | .name = "cfs_quota_us", | |
7826 | .read_s64 = cpu_cfs_quota_read_s64, | |
7827 | .write_s64 = cpu_cfs_quota_write_s64, | |
7828 | }, | |
7829 | { | |
7830 | .name = "cfs_period_us", | |
7831 | .read_u64 = cpu_cfs_period_read_u64, | |
7832 | .write_u64 = cpu_cfs_period_write_u64, | |
7833 | }, | |
e8da1b18 NR |
7834 | { |
7835 | .name = "stat", | |
7836 | .read_map = cpu_stats_show, | |
7837 | }, | |
ab84d31e | 7838 | #endif |
052f1dc7 | 7839 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 7840 | { |
9f0c1e56 | 7841 | .name = "rt_runtime_us", |
06ecb27c PM |
7842 | .read_s64 = cpu_rt_runtime_read, |
7843 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 7844 | }, |
d0b27fa7 PZ |
7845 | { |
7846 | .name = "rt_period_us", | |
f4c753b7 PM |
7847 | .read_u64 = cpu_rt_period_read_uint, |
7848 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 7849 | }, |
052f1dc7 | 7850 | #endif |
68318b8e SV |
7851 | }; |
7852 | ||
7853 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
7854 | { | |
fe5c7cc2 | 7855 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
7856 | } |
7857 | ||
7858 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
7859 | .name = "cpu", |
7860 | .create = cpu_cgroup_create, | |
7861 | .destroy = cpu_cgroup_destroy, | |
f780bdb7 BB |
7862 | .can_attach_task = cpu_cgroup_can_attach_task, |
7863 | .attach_task = cpu_cgroup_attach_task, | |
068c5cc5 | 7864 | .exit = cpu_cgroup_exit, |
38605cae IM |
7865 | .populate = cpu_cgroup_populate, |
7866 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
7867 | .early_init = 1, |
7868 | }; | |
7869 | ||
052f1dc7 | 7870 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
7871 | |
7872 | #ifdef CONFIG_CGROUP_CPUACCT | |
7873 | ||
7874 | /* | |
7875 | * CPU accounting code for task groups. | |
7876 | * | |
7877 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
7878 | * (balbir@in.ibm.com). | |
7879 | */ | |
7880 | ||
d842de87 SV |
7881 | /* create a new cpu accounting group */ |
7882 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 7883 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 7884 | { |
54c707e9 | 7885 | struct cpuacct *ca; |
d842de87 | 7886 | |
54c707e9 GC |
7887 | if (!cgrp->parent) |
7888 | return &root_cpuacct.css; | |
7889 | ||
7890 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
d842de87 | 7891 | if (!ca) |
ef12fefa | 7892 | goto out; |
d842de87 SV |
7893 | |
7894 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
7895 | if (!ca->cpuusage) |
7896 | goto out_free_ca; | |
7897 | ||
54c707e9 GC |
7898 | ca->cpustat = alloc_percpu(struct kernel_cpustat); |
7899 | if (!ca->cpustat) | |
7900 | goto out_free_cpuusage; | |
d842de87 SV |
7901 | |
7902 | return &ca->css; | |
ef12fefa | 7903 | |
54c707e9 | 7904 | out_free_cpuusage: |
ef12fefa BR |
7905 | free_percpu(ca->cpuusage); |
7906 | out_free_ca: | |
7907 | kfree(ca); | |
7908 | out: | |
7909 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
7910 | } |
7911 | ||
7912 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 7913 | static void |
32cd756a | 7914 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 7915 | { |
32cd756a | 7916 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 | 7917 | |
54c707e9 | 7918 | free_percpu(ca->cpustat); |
d842de87 SV |
7919 | free_percpu(ca->cpuusage); |
7920 | kfree(ca); | |
7921 | } | |
7922 | ||
720f5498 KC |
7923 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
7924 | { | |
b36128c8 | 7925 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
7926 | u64 data; |
7927 | ||
7928 | #ifndef CONFIG_64BIT | |
7929 | /* | |
7930 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
7931 | */ | |
05fa785c | 7932 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 7933 | data = *cpuusage; |
05fa785c | 7934 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
7935 | #else |
7936 | data = *cpuusage; | |
7937 | #endif | |
7938 | ||
7939 | return data; | |
7940 | } | |
7941 | ||
7942 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
7943 | { | |
b36128c8 | 7944 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
7945 | |
7946 | #ifndef CONFIG_64BIT | |
7947 | /* | |
7948 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
7949 | */ | |
05fa785c | 7950 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 7951 | *cpuusage = val; |
05fa785c | 7952 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
7953 | #else |
7954 | *cpuusage = val; | |
7955 | #endif | |
7956 | } | |
7957 | ||
d842de87 | 7958 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 7959 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 7960 | { |
32cd756a | 7961 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
7962 | u64 totalcpuusage = 0; |
7963 | int i; | |
7964 | ||
720f5498 KC |
7965 | for_each_present_cpu(i) |
7966 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
7967 | |
7968 | return totalcpuusage; | |
7969 | } | |
7970 | ||
0297b803 DG |
7971 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
7972 | u64 reset) | |
7973 | { | |
7974 | struct cpuacct *ca = cgroup_ca(cgrp); | |
7975 | int err = 0; | |
7976 | int i; | |
7977 | ||
7978 | if (reset) { | |
7979 | err = -EINVAL; | |
7980 | goto out; | |
7981 | } | |
7982 | ||
720f5498 KC |
7983 | for_each_present_cpu(i) |
7984 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 7985 | |
0297b803 DG |
7986 | out: |
7987 | return err; | |
7988 | } | |
7989 | ||
e9515c3c KC |
7990 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
7991 | struct seq_file *m) | |
7992 | { | |
7993 | struct cpuacct *ca = cgroup_ca(cgroup); | |
7994 | u64 percpu; | |
7995 | int i; | |
7996 | ||
7997 | for_each_present_cpu(i) { | |
7998 | percpu = cpuacct_cpuusage_read(ca, i); | |
7999 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
8000 | } | |
8001 | seq_printf(m, "\n"); | |
8002 | return 0; | |
8003 | } | |
8004 | ||
ef12fefa BR |
8005 | static const char *cpuacct_stat_desc[] = { |
8006 | [CPUACCT_STAT_USER] = "user", | |
8007 | [CPUACCT_STAT_SYSTEM] = "system", | |
8008 | }; | |
8009 | ||
8010 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
54c707e9 | 8011 | struct cgroup_map_cb *cb) |
ef12fefa BR |
8012 | { |
8013 | struct cpuacct *ca = cgroup_ca(cgrp); | |
54c707e9 GC |
8014 | int cpu; |
8015 | s64 val = 0; | |
ef12fefa | 8016 | |
54c707e9 GC |
8017 | for_each_online_cpu(cpu) { |
8018 | struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); | |
8019 | val += kcpustat->cpustat[CPUTIME_USER]; | |
8020 | val += kcpustat->cpustat[CPUTIME_NICE]; | |
ef12fefa | 8021 | } |
54c707e9 GC |
8022 | val = cputime64_to_clock_t(val); |
8023 | cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val); | |
8024 | ||
8025 | val = 0; | |
8026 | for_each_online_cpu(cpu) { | |
8027 | struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); | |
8028 | val += kcpustat->cpustat[CPUTIME_SYSTEM]; | |
8029 | val += kcpustat->cpustat[CPUTIME_IRQ]; | |
8030 | val += kcpustat->cpustat[CPUTIME_SOFTIRQ]; | |
8031 | } | |
8032 | ||
8033 | val = cputime64_to_clock_t(val); | |
8034 | cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val); | |
8035 | ||
ef12fefa BR |
8036 | return 0; |
8037 | } | |
8038 | ||
d842de87 SV |
8039 | static struct cftype files[] = { |
8040 | { | |
8041 | .name = "usage", | |
f4c753b7 PM |
8042 | .read_u64 = cpuusage_read, |
8043 | .write_u64 = cpuusage_write, | |
d842de87 | 8044 | }, |
e9515c3c KC |
8045 | { |
8046 | .name = "usage_percpu", | |
8047 | .read_seq_string = cpuacct_percpu_seq_read, | |
8048 | }, | |
ef12fefa BR |
8049 | { |
8050 | .name = "stat", | |
8051 | .read_map = cpuacct_stats_show, | |
8052 | }, | |
d842de87 SV |
8053 | }; |
8054 | ||
32cd756a | 8055 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8056 | { |
32cd756a | 8057 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
8058 | } |
8059 | ||
8060 | /* | |
8061 | * charge this task's execution time to its accounting group. | |
8062 | * | |
8063 | * called with rq->lock held. | |
8064 | */ | |
029632fb | 8065 | void cpuacct_charge(struct task_struct *tsk, u64 cputime) |
d842de87 SV |
8066 | { |
8067 | struct cpuacct *ca; | |
934352f2 | 8068 | int cpu; |
d842de87 | 8069 | |
c40c6f85 | 8070 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
8071 | return; |
8072 | ||
934352f2 | 8073 | cpu = task_cpu(tsk); |
a18b83b7 BR |
8074 | |
8075 | rcu_read_lock(); | |
8076 | ||
d842de87 | 8077 | ca = task_ca(tsk); |
d842de87 | 8078 | |
44252e42 | 8079 | for (; ca; ca = parent_ca(ca)) { |
b36128c8 | 8080 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
8081 | *cpuusage += cputime; |
8082 | } | |
a18b83b7 BR |
8083 | |
8084 | rcu_read_unlock(); | |
d842de87 SV |
8085 | } |
8086 | ||
8087 | struct cgroup_subsys cpuacct_subsys = { | |
8088 | .name = "cpuacct", | |
8089 | .create = cpuacct_create, | |
8090 | .destroy = cpuacct_destroy, | |
8091 | .populate = cpuacct_populate, | |
8092 | .subsys_id = cpuacct_subsys_id, | |
8093 | }; | |
8094 | #endif /* CONFIG_CGROUP_CPUACCT */ |