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Commit | Line | Data |
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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> |
40401530 | 74 | #include <linux/binfmts.h> |
1da177e4 | 75 | |
96f951ed | 76 | #include <asm/switch_to.h> |
5517d86b | 77 | #include <asm/tlb.h> |
838225b4 | 78 | #include <asm/irq_regs.h> |
db7e527d | 79 | #include <asm/mutex.h> |
e6e6685a GC |
80 | #ifdef CONFIG_PARAVIRT |
81 | #include <asm/paravirt.h> | |
82 | #endif | |
1da177e4 | 83 | |
029632fb | 84 | #include "sched.h" |
391e43da | 85 | #include "../workqueue_sched.h" |
29d5e047 | 86 | #include "../smpboot.h" |
6e0534f2 | 87 | |
a8d154b0 | 88 | #define CREATE_TRACE_POINTS |
ad8d75ff | 89 | #include <trace/events/sched.h> |
a8d154b0 | 90 | |
029632fb | 91 | void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) |
d0b27fa7 | 92 | { |
58088ad0 PT |
93 | unsigned long delta; |
94 | ktime_t soft, hard, now; | |
d0b27fa7 | 95 | |
58088ad0 PT |
96 | for (;;) { |
97 | if (hrtimer_active(period_timer)) | |
98 | break; | |
99 | ||
100 | now = hrtimer_cb_get_time(period_timer); | |
101 | hrtimer_forward(period_timer, now, period); | |
d0b27fa7 | 102 | |
58088ad0 PT |
103 | soft = hrtimer_get_softexpires(period_timer); |
104 | hard = hrtimer_get_expires(period_timer); | |
105 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
106 | __hrtimer_start_range_ns(period_timer, soft, delta, | |
107 | HRTIMER_MODE_ABS_PINNED, 0); | |
108 | } | |
109 | } | |
110 | ||
029632fb PZ |
111 | DEFINE_MUTEX(sched_domains_mutex); |
112 | DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); | |
dc61b1d6 | 113 | |
fe44d621 | 114 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 115 | |
029632fb | 116 | void update_rq_clock(struct rq *rq) |
3e51f33f | 117 | { |
fe44d621 | 118 | s64 delta; |
305e6835 | 119 | |
61eadef6 | 120 | if (rq->skip_clock_update > 0) |
f26f9aff | 121 | return; |
aa483808 | 122 | |
fe44d621 PZ |
123 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
124 | rq->clock += delta; | |
125 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
126 | } |
127 | ||
bf5c91ba IM |
128 | /* |
129 | * Debugging: various feature bits | |
130 | */ | |
f00b45c1 | 131 | |
f00b45c1 PZ |
132 | #define SCHED_FEAT(name, enabled) \ |
133 | (1UL << __SCHED_FEAT_##name) * enabled | | |
134 | ||
bf5c91ba | 135 | const_debug unsigned int sysctl_sched_features = |
391e43da | 136 | #include "features.h" |
f00b45c1 PZ |
137 | 0; |
138 | ||
139 | #undef SCHED_FEAT | |
140 | ||
141 | #ifdef CONFIG_SCHED_DEBUG | |
142 | #define SCHED_FEAT(name, enabled) \ | |
143 | #name , | |
144 | ||
1292531f | 145 | static const char * const sched_feat_names[] = { |
391e43da | 146 | #include "features.h" |
f00b45c1 PZ |
147 | }; |
148 | ||
149 | #undef SCHED_FEAT | |
150 | ||
34f3a814 | 151 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 152 | { |
f00b45c1 PZ |
153 | int i; |
154 | ||
f8b6d1cc | 155 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
34f3a814 LZ |
156 | if (!(sysctl_sched_features & (1UL << i))) |
157 | seq_puts(m, "NO_"); | |
158 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 159 | } |
34f3a814 | 160 | seq_puts(m, "\n"); |
f00b45c1 | 161 | |
34f3a814 | 162 | return 0; |
f00b45c1 PZ |
163 | } |
164 | ||
f8b6d1cc PZ |
165 | #ifdef HAVE_JUMP_LABEL |
166 | ||
c5905afb IM |
167 | #define jump_label_key__true STATIC_KEY_INIT_TRUE |
168 | #define jump_label_key__false STATIC_KEY_INIT_FALSE | |
f8b6d1cc PZ |
169 | |
170 | #define SCHED_FEAT(name, enabled) \ | |
171 | jump_label_key__##enabled , | |
172 | ||
c5905afb | 173 | struct static_key sched_feat_keys[__SCHED_FEAT_NR] = { |
f8b6d1cc PZ |
174 | #include "features.h" |
175 | }; | |
176 | ||
177 | #undef SCHED_FEAT | |
178 | ||
179 | static void sched_feat_disable(int i) | |
180 | { | |
c5905afb IM |
181 | if (static_key_enabled(&sched_feat_keys[i])) |
182 | static_key_slow_dec(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
183 | } |
184 | ||
185 | static void sched_feat_enable(int i) | |
186 | { | |
c5905afb IM |
187 | if (!static_key_enabled(&sched_feat_keys[i])) |
188 | static_key_slow_inc(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
189 | } |
190 | #else | |
191 | static void sched_feat_disable(int i) { }; | |
192 | static void sched_feat_enable(int i) { }; | |
193 | #endif /* HAVE_JUMP_LABEL */ | |
194 | ||
f00b45c1 PZ |
195 | static ssize_t |
196 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
197 | size_t cnt, loff_t *ppos) | |
198 | { | |
199 | char buf[64]; | |
7740191c | 200 | char *cmp; |
f00b45c1 PZ |
201 | int neg = 0; |
202 | int i; | |
203 | ||
204 | if (cnt > 63) | |
205 | cnt = 63; | |
206 | ||
207 | if (copy_from_user(&buf, ubuf, cnt)) | |
208 | return -EFAULT; | |
209 | ||
210 | buf[cnt] = 0; | |
7740191c | 211 | cmp = strstrip(buf); |
f00b45c1 | 212 | |
524429c3 | 213 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
214 | neg = 1; |
215 | cmp += 3; | |
216 | } | |
217 | ||
f8b6d1cc | 218 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
7740191c | 219 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f8b6d1cc | 220 | if (neg) { |
f00b45c1 | 221 | sysctl_sched_features &= ~(1UL << i); |
f8b6d1cc PZ |
222 | sched_feat_disable(i); |
223 | } else { | |
f00b45c1 | 224 | sysctl_sched_features |= (1UL << i); |
f8b6d1cc PZ |
225 | sched_feat_enable(i); |
226 | } | |
f00b45c1 PZ |
227 | break; |
228 | } | |
229 | } | |
230 | ||
f8b6d1cc | 231 | if (i == __SCHED_FEAT_NR) |
f00b45c1 PZ |
232 | return -EINVAL; |
233 | ||
42994724 | 234 | *ppos += cnt; |
f00b45c1 PZ |
235 | |
236 | return cnt; | |
237 | } | |
238 | ||
34f3a814 LZ |
239 | static int sched_feat_open(struct inode *inode, struct file *filp) |
240 | { | |
241 | return single_open(filp, sched_feat_show, NULL); | |
242 | } | |
243 | ||
828c0950 | 244 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
245 | .open = sched_feat_open, |
246 | .write = sched_feat_write, | |
247 | .read = seq_read, | |
248 | .llseek = seq_lseek, | |
249 | .release = single_release, | |
f00b45c1 PZ |
250 | }; |
251 | ||
252 | static __init int sched_init_debug(void) | |
253 | { | |
f00b45c1 PZ |
254 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
255 | &sched_feat_fops); | |
256 | ||
257 | return 0; | |
258 | } | |
259 | late_initcall(sched_init_debug); | |
f8b6d1cc | 260 | #endif /* CONFIG_SCHED_DEBUG */ |
bf5c91ba | 261 | |
b82d9fdd PZ |
262 | /* |
263 | * Number of tasks to iterate in a single balance run. | |
264 | * Limited because this is done with IRQs disabled. | |
265 | */ | |
266 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
267 | ||
e9e9250b PZ |
268 | /* |
269 | * period over which we average the RT time consumption, measured | |
270 | * in ms. | |
271 | * | |
272 | * default: 1s | |
273 | */ | |
274 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
275 | ||
fa85ae24 | 276 | /* |
9f0c1e56 | 277 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
278 | * default: 1s |
279 | */ | |
9f0c1e56 | 280 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 281 | |
029632fb | 282 | __read_mostly int scheduler_running; |
6892b75e | 283 | |
9f0c1e56 PZ |
284 | /* |
285 | * part of the period that we allow rt tasks to run in us. | |
286 | * default: 0.95s | |
287 | */ | |
288 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 289 | |
fa85ae24 | 290 | |
1da177e4 | 291 | |
0970d299 | 292 | /* |
0122ec5b | 293 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 294 | */ |
70b97a7f | 295 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
296 | __acquires(rq->lock) |
297 | { | |
0970d299 PZ |
298 | struct rq *rq; |
299 | ||
0122ec5b PZ |
300 | lockdep_assert_held(&p->pi_lock); |
301 | ||
3a5c359a | 302 | for (;;) { |
0970d299 | 303 | rq = task_rq(p); |
05fa785c | 304 | raw_spin_lock(&rq->lock); |
65cc8e48 | 305 | if (likely(rq == task_rq(p))) |
3a5c359a | 306 | return rq; |
05fa785c | 307 | raw_spin_unlock(&rq->lock); |
b29739f9 | 308 | } |
b29739f9 IM |
309 | } |
310 | ||
1da177e4 | 311 | /* |
0122ec5b | 312 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 313 | */ |
70b97a7f | 314 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 315 | __acquires(p->pi_lock) |
1da177e4 LT |
316 | __acquires(rq->lock) |
317 | { | |
70b97a7f | 318 | struct rq *rq; |
1da177e4 | 319 | |
3a5c359a | 320 | for (;;) { |
0122ec5b | 321 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 322 | rq = task_rq(p); |
05fa785c | 323 | raw_spin_lock(&rq->lock); |
65cc8e48 | 324 | if (likely(rq == task_rq(p))) |
3a5c359a | 325 | return rq; |
0122ec5b PZ |
326 | raw_spin_unlock(&rq->lock); |
327 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 328 | } |
1da177e4 LT |
329 | } |
330 | ||
a9957449 | 331 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
332 | __releases(rq->lock) |
333 | { | |
05fa785c | 334 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
335 | } |
336 | ||
0122ec5b PZ |
337 | static inline void |
338 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 339 | __releases(rq->lock) |
0122ec5b | 340 | __releases(p->pi_lock) |
1da177e4 | 341 | { |
0122ec5b PZ |
342 | raw_spin_unlock(&rq->lock); |
343 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
344 | } |
345 | ||
1da177e4 | 346 | /* |
cc2a73b5 | 347 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 348 | */ |
a9957449 | 349 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
350 | __acquires(rq->lock) |
351 | { | |
70b97a7f | 352 | struct rq *rq; |
1da177e4 LT |
353 | |
354 | local_irq_disable(); | |
355 | rq = this_rq(); | |
05fa785c | 356 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
357 | |
358 | return rq; | |
359 | } | |
360 | ||
8f4d37ec PZ |
361 | #ifdef CONFIG_SCHED_HRTICK |
362 | /* | |
363 | * Use HR-timers to deliver accurate preemption points. | |
364 | * | |
365 | * Its all a bit involved since we cannot program an hrt while holding the | |
366 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
367 | * reschedule event. | |
368 | * | |
369 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
370 | * rq->lock. | |
371 | */ | |
8f4d37ec | 372 | |
8f4d37ec PZ |
373 | static void hrtick_clear(struct rq *rq) |
374 | { | |
375 | if (hrtimer_active(&rq->hrtick_timer)) | |
376 | hrtimer_cancel(&rq->hrtick_timer); | |
377 | } | |
378 | ||
8f4d37ec PZ |
379 | /* |
380 | * High-resolution timer tick. | |
381 | * Runs from hardirq context with interrupts disabled. | |
382 | */ | |
383 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
384 | { | |
385 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
386 | ||
387 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
388 | ||
05fa785c | 389 | raw_spin_lock(&rq->lock); |
3e51f33f | 390 | update_rq_clock(rq); |
8f4d37ec | 391 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 392 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
393 | |
394 | return HRTIMER_NORESTART; | |
395 | } | |
396 | ||
95e904c7 | 397 | #ifdef CONFIG_SMP |
31656519 PZ |
398 | /* |
399 | * called from hardirq (IPI) context | |
400 | */ | |
401 | static void __hrtick_start(void *arg) | |
b328ca18 | 402 | { |
31656519 | 403 | struct rq *rq = arg; |
b328ca18 | 404 | |
05fa785c | 405 | raw_spin_lock(&rq->lock); |
31656519 PZ |
406 | hrtimer_restart(&rq->hrtick_timer); |
407 | rq->hrtick_csd_pending = 0; | |
05fa785c | 408 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
409 | } |
410 | ||
31656519 PZ |
411 | /* |
412 | * Called to set the hrtick timer state. | |
413 | * | |
414 | * called with rq->lock held and irqs disabled | |
415 | */ | |
029632fb | 416 | void hrtick_start(struct rq *rq, u64 delay) |
b328ca18 | 417 | { |
31656519 PZ |
418 | struct hrtimer *timer = &rq->hrtick_timer; |
419 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 420 | |
cc584b21 | 421 | hrtimer_set_expires(timer, time); |
31656519 PZ |
422 | |
423 | if (rq == this_rq()) { | |
424 | hrtimer_restart(timer); | |
425 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 426 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
427 | rq->hrtick_csd_pending = 1; |
428 | } | |
b328ca18 PZ |
429 | } |
430 | ||
431 | static int | |
432 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
433 | { | |
434 | int cpu = (int)(long)hcpu; | |
435 | ||
436 | switch (action) { | |
437 | case CPU_UP_CANCELED: | |
438 | case CPU_UP_CANCELED_FROZEN: | |
439 | case CPU_DOWN_PREPARE: | |
440 | case CPU_DOWN_PREPARE_FROZEN: | |
441 | case CPU_DEAD: | |
442 | case CPU_DEAD_FROZEN: | |
31656519 | 443 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
444 | return NOTIFY_OK; |
445 | } | |
446 | ||
447 | return NOTIFY_DONE; | |
448 | } | |
449 | ||
fa748203 | 450 | static __init void init_hrtick(void) |
b328ca18 PZ |
451 | { |
452 | hotcpu_notifier(hotplug_hrtick, 0); | |
453 | } | |
31656519 PZ |
454 | #else |
455 | /* | |
456 | * Called to set the hrtick timer state. | |
457 | * | |
458 | * called with rq->lock held and irqs disabled | |
459 | */ | |
029632fb | 460 | void hrtick_start(struct rq *rq, u64 delay) |
31656519 | 461 | { |
7f1e2ca9 | 462 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 463 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 464 | } |
b328ca18 | 465 | |
006c75f1 | 466 | static inline void init_hrtick(void) |
8f4d37ec | 467 | { |
8f4d37ec | 468 | } |
31656519 | 469 | #endif /* CONFIG_SMP */ |
8f4d37ec | 470 | |
31656519 | 471 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 472 | { |
31656519 PZ |
473 | #ifdef CONFIG_SMP |
474 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 475 | |
31656519 PZ |
476 | rq->hrtick_csd.flags = 0; |
477 | rq->hrtick_csd.func = __hrtick_start; | |
478 | rq->hrtick_csd.info = rq; | |
479 | #endif | |
8f4d37ec | 480 | |
31656519 PZ |
481 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
482 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 483 | } |
006c75f1 | 484 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
485 | static inline void hrtick_clear(struct rq *rq) |
486 | { | |
487 | } | |
488 | ||
8f4d37ec PZ |
489 | static inline void init_rq_hrtick(struct rq *rq) |
490 | { | |
491 | } | |
492 | ||
b328ca18 PZ |
493 | static inline void init_hrtick(void) |
494 | { | |
495 | } | |
006c75f1 | 496 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 497 | |
c24d20db IM |
498 | /* |
499 | * resched_task - mark a task 'to be rescheduled now'. | |
500 | * | |
501 | * On UP this means the setting of the need_resched flag, on SMP it | |
502 | * might also involve a cross-CPU call to trigger the scheduler on | |
503 | * the target CPU. | |
504 | */ | |
505 | #ifdef CONFIG_SMP | |
506 | ||
507 | #ifndef tsk_is_polling | |
16a80163 | 508 | #define tsk_is_polling(t) 0 |
c24d20db IM |
509 | #endif |
510 | ||
029632fb | 511 | void resched_task(struct task_struct *p) |
c24d20db IM |
512 | { |
513 | int cpu; | |
514 | ||
05fa785c | 515 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 516 | |
5ed0cec0 | 517 | if (test_tsk_need_resched(p)) |
c24d20db IM |
518 | return; |
519 | ||
5ed0cec0 | 520 | set_tsk_need_resched(p); |
c24d20db IM |
521 | |
522 | cpu = task_cpu(p); | |
523 | if (cpu == smp_processor_id()) | |
524 | return; | |
525 | ||
526 | /* NEED_RESCHED must be visible before we test polling */ | |
527 | smp_mb(); | |
528 | if (!tsk_is_polling(p)) | |
529 | smp_send_reschedule(cpu); | |
530 | } | |
531 | ||
029632fb | 532 | void resched_cpu(int cpu) |
c24d20db IM |
533 | { |
534 | struct rq *rq = cpu_rq(cpu); | |
535 | unsigned long flags; | |
536 | ||
05fa785c | 537 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
538 | return; |
539 | resched_task(cpu_curr(cpu)); | |
05fa785c | 540 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 541 | } |
06d8308c TG |
542 | |
543 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
544 | /* |
545 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
546 | * from an idle cpu. This is good for power-savings. | |
547 | * | |
548 | * We don't do similar optimization for completely idle system, as | |
549 | * selecting an idle cpu will add more delays to the timers than intended | |
550 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
551 | */ | |
552 | int get_nohz_timer_target(void) | |
553 | { | |
554 | int cpu = smp_processor_id(); | |
555 | int i; | |
556 | struct sched_domain *sd; | |
557 | ||
057f3fad | 558 | rcu_read_lock(); |
83cd4fe2 | 559 | for_each_domain(cpu, sd) { |
057f3fad PZ |
560 | for_each_cpu(i, sched_domain_span(sd)) { |
561 | if (!idle_cpu(i)) { | |
562 | cpu = i; | |
563 | goto unlock; | |
564 | } | |
565 | } | |
83cd4fe2 | 566 | } |
057f3fad PZ |
567 | unlock: |
568 | rcu_read_unlock(); | |
83cd4fe2 VP |
569 | return cpu; |
570 | } | |
06d8308c TG |
571 | /* |
572 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
573 | * idle CPU then this timer might expire before the next timer event | |
574 | * which is scheduled to wake up that CPU. In case of a completely | |
575 | * idle system the next event might even be infinite time into the | |
576 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
577 | * leaves the inner idle loop so the newly added timer is taken into | |
578 | * account when the CPU goes back to idle and evaluates the timer | |
579 | * wheel for the next timer event. | |
580 | */ | |
581 | void wake_up_idle_cpu(int cpu) | |
582 | { | |
583 | struct rq *rq = cpu_rq(cpu); | |
584 | ||
585 | if (cpu == smp_processor_id()) | |
586 | return; | |
587 | ||
588 | /* | |
589 | * This is safe, as this function is called with the timer | |
590 | * wheel base lock of (cpu) held. When the CPU is on the way | |
591 | * to idle and has not yet set rq->curr to idle then it will | |
592 | * be serialized on the timer wheel base lock and take the new | |
593 | * timer into account automatically. | |
594 | */ | |
595 | if (rq->curr != rq->idle) | |
596 | return; | |
45bf76df | 597 | |
45bf76df | 598 | /* |
06d8308c TG |
599 | * We can set TIF_RESCHED on the idle task of the other CPU |
600 | * lockless. The worst case is that the other CPU runs the | |
601 | * idle task through an additional NOOP schedule() | |
45bf76df | 602 | */ |
5ed0cec0 | 603 | set_tsk_need_resched(rq->idle); |
45bf76df | 604 | |
06d8308c TG |
605 | /* NEED_RESCHED must be visible before we test polling */ |
606 | smp_mb(); | |
607 | if (!tsk_is_polling(rq->idle)) | |
608 | smp_send_reschedule(cpu); | |
45bf76df IM |
609 | } |
610 | ||
ca38062e | 611 | static inline bool got_nohz_idle_kick(void) |
45bf76df | 612 | { |
1c792db7 SS |
613 | int cpu = smp_processor_id(); |
614 | return idle_cpu(cpu) && test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)); | |
45bf76df IM |
615 | } |
616 | ||
ca38062e | 617 | #else /* CONFIG_NO_HZ */ |
45bf76df | 618 | |
ca38062e | 619 | static inline bool got_nohz_idle_kick(void) |
2069dd75 | 620 | { |
ca38062e | 621 | return false; |
2069dd75 PZ |
622 | } |
623 | ||
6d6bc0ad | 624 | #endif /* CONFIG_NO_HZ */ |
d842de87 | 625 | |
029632fb | 626 | void sched_avg_update(struct rq *rq) |
18d95a28 | 627 | { |
e9e9250b PZ |
628 | s64 period = sched_avg_period(); |
629 | ||
630 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
0d98bb26 WD |
631 | /* |
632 | * Inline assembly required to prevent the compiler | |
633 | * optimising this loop into a divmod call. | |
634 | * See __iter_div_u64_rem() for another example of this. | |
635 | */ | |
636 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
637 | rq->age_stamp += period; |
638 | rq->rt_avg /= 2; | |
639 | } | |
18d95a28 PZ |
640 | } |
641 | ||
6d6bc0ad | 642 | #else /* !CONFIG_SMP */ |
029632fb | 643 | void resched_task(struct task_struct *p) |
18d95a28 | 644 | { |
05fa785c | 645 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 646 | set_tsk_need_resched(p); |
18d95a28 | 647 | } |
6d6bc0ad | 648 | #endif /* CONFIG_SMP */ |
18d95a28 | 649 | |
a790de99 PT |
650 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
651 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
c09595f6 | 652 | /* |
8277434e PT |
653 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
654 | * node and @up when leaving it for the final time. | |
655 | * | |
656 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 657 | */ |
029632fb | 658 | int walk_tg_tree_from(struct task_group *from, |
8277434e | 659 | tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
660 | { |
661 | struct task_group *parent, *child; | |
eb755805 | 662 | int ret; |
c09595f6 | 663 | |
8277434e PT |
664 | parent = from; |
665 | ||
c09595f6 | 666 | down: |
eb755805 PZ |
667 | ret = (*down)(parent, data); |
668 | if (ret) | |
8277434e | 669 | goto out; |
c09595f6 PZ |
670 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
671 | parent = child; | |
672 | goto down; | |
673 | ||
674 | up: | |
675 | continue; | |
676 | } | |
eb755805 | 677 | ret = (*up)(parent, data); |
8277434e PT |
678 | if (ret || parent == from) |
679 | goto out; | |
c09595f6 PZ |
680 | |
681 | child = parent; | |
682 | parent = parent->parent; | |
683 | if (parent) | |
684 | goto up; | |
8277434e | 685 | out: |
eb755805 | 686 | return ret; |
c09595f6 PZ |
687 | } |
688 | ||
029632fb | 689 | int tg_nop(struct task_group *tg, void *data) |
eb755805 | 690 | { |
e2b245f8 | 691 | return 0; |
eb755805 | 692 | } |
18d95a28 PZ |
693 | #endif |
694 | ||
45bf76df IM |
695 | static void set_load_weight(struct task_struct *p) |
696 | { | |
f05998d4 NR |
697 | int prio = p->static_prio - MAX_RT_PRIO; |
698 | struct load_weight *load = &p->se.load; | |
699 | ||
dd41f596 IM |
700 | /* |
701 | * SCHED_IDLE tasks get minimal weight: | |
702 | */ | |
703 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 704 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 705 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
706 | return; |
707 | } | |
71f8bd46 | 708 | |
c8b28116 | 709 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 710 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
711 | } |
712 | ||
371fd7e7 | 713 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 714 | { |
a64692a3 | 715 | update_rq_clock(rq); |
dd41f596 | 716 | sched_info_queued(p); |
371fd7e7 | 717 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
718 | } |
719 | ||
371fd7e7 | 720 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 721 | { |
a64692a3 | 722 | update_rq_clock(rq); |
46ac22ba | 723 | sched_info_dequeued(p); |
371fd7e7 | 724 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
725 | } |
726 | ||
029632fb | 727 | void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
728 | { |
729 | if (task_contributes_to_load(p)) | |
730 | rq->nr_uninterruptible--; | |
731 | ||
371fd7e7 | 732 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
733 | } |
734 | ||
029632fb | 735 | void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
736 | { |
737 | if (task_contributes_to_load(p)) | |
738 | rq->nr_uninterruptible++; | |
739 | ||
371fd7e7 | 740 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
741 | } |
742 | ||
fe44d621 | 743 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 744 | { |
095c0aa8 GC |
745 | /* |
746 | * In theory, the compile should just see 0 here, and optimize out the call | |
747 | * to sched_rt_avg_update. But I don't trust it... | |
748 | */ | |
749 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
750 | s64 steal = 0, irq_delta = 0; | |
751 | #endif | |
752 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 753 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
754 | |
755 | /* | |
756 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
757 | * this case when a previous update_rq_clock() happened inside a | |
758 | * {soft,}irq region. | |
759 | * | |
760 | * When this happens, we stop ->clock_task and only update the | |
761 | * prev_irq_time stamp to account for the part that fit, so that a next | |
762 | * update will consume the rest. This ensures ->clock_task is | |
763 | * monotonic. | |
764 | * | |
765 | * It does however cause some slight miss-attribution of {soft,}irq | |
766 | * time, a more accurate solution would be to update the irq_time using | |
767 | * the current rq->clock timestamp, except that would require using | |
768 | * atomic ops. | |
769 | */ | |
770 | if (irq_delta > delta) | |
771 | irq_delta = delta; | |
772 | ||
773 | rq->prev_irq_time += irq_delta; | |
774 | delta -= irq_delta; | |
095c0aa8 GC |
775 | #endif |
776 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
c5905afb | 777 | if (static_key_false((¶virt_steal_rq_enabled))) { |
095c0aa8 GC |
778 | u64 st; |
779 | ||
780 | steal = paravirt_steal_clock(cpu_of(rq)); | |
781 | steal -= rq->prev_steal_time_rq; | |
782 | ||
783 | if (unlikely(steal > delta)) | |
784 | steal = delta; | |
785 | ||
786 | st = steal_ticks(steal); | |
787 | steal = st * TICK_NSEC; | |
788 | ||
789 | rq->prev_steal_time_rq += steal; | |
790 | ||
791 | delta -= steal; | |
792 | } | |
793 | #endif | |
794 | ||
fe44d621 PZ |
795 | rq->clock_task += delta; |
796 | ||
095c0aa8 GC |
797 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
798 | if ((irq_delta + steal) && sched_feat(NONTASK_POWER)) | |
799 | sched_rt_avg_update(rq, irq_delta + steal); | |
800 | #endif | |
aa483808 VP |
801 | } |
802 | ||
34f971f6 PZ |
803 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
804 | { | |
805 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
806 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
807 | ||
808 | if (stop) { | |
809 | /* | |
810 | * Make it appear like a SCHED_FIFO task, its something | |
811 | * userspace knows about and won't get confused about. | |
812 | * | |
813 | * Also, it will make PI more or less work without too | |
814 | * much confusion -- but then, stop work should not | |
815 | * rely on PI working anyway. | |
816 | */ | |
817 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
818 | ||
819 | stop->sched_class = &stop_sched_class; | |
820 | } | |
821 | ||
822 | cpu_rq(cpu)->stop = stop; | |
823 | ||
824 | if (old_stop) { | |
825 | /* | |
826 | * Reset it back to a normal scheduling class so that | |
827 | * it can die in pieces. | |
828 | */ | |
829 | old_stop->sched_class = &rt_sched_class; | |
830 | } | |
831 | } | |
832 | ||
14531189 | 833 | /* |
dd41f596 | 834 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 835 | */ |
14531189 IM |
836 | static inline int __normal_prio(struct task_struct *p) |
837 | { | |
dd41f596 | 838 | return p->static_prio; |
14531189 IM |
839 | } |
840 | ||
b29739f9 IM |
841 | /* |
842 | * Calculate the expected normal priority: i.e. priority | |
843 | * without taking RT-inheritance into account. Might be | |
844 | * boosted by interactivity modifiers. Changes upon fork, | |
845 | * setprio syscalls, and whenever the interactivity | |
846 | * estimator recalculates. | |
847 | */ | |
36c8b586 | 848 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
849 | { |
850 | int prio; | |
851 | ||
e05606d3 | 852 | if (task_has_rt_policy(p)) |
b29739f9 IM |
853 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
854 | else | |
855 | prio = __normal_prio(p); | |
856 | return prio; | |
857 | } | |
858 | ||
859 | /* | |
860 | * Calculate the current priority, i.e. the priority | |
861 | * taken into account by the scheduler. This value might | |
862 | * be boosted by RT tasks, or might be boosted by | |
863 | * interactivity modifiers. Will be RT if the task got | |
864 | * RT-boosted. If not then it returns p->normal_prio. | |
865 | */ | |
36c8b586 | 866 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
867 | { |
868 | p->normal_prio = normal_prio(p); | |
869 | /* | |
870 | * If we are RT tasks or we were boosted to RT priority, | |
871 | * keep the priority unchanged. Otherwise, update priority | |
872 | * to the normal priority: | |
873 | */ | |
874 | if (!rt_prio(p->prio)) | |
875 | return p->normal_prio; | |
876 | return p->prio; | |
877 | } | |
878 | ||
1da177e4 LT |
879 | /** |
880 | * task_curr - is this task currently executing on a CPU? | |
881 | * @p: the task in question. | |
882 | */ | |
36c8b586 | 883 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
884 | { |
885 | return cpu_curr(task_cpu(p)) == p; | |
886 | } | |
887 | ||
cb469845 SR |
888 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
889 | const struct sched_class *prev_class, | |
da7a735e | 890 | int oldprio) |
cb469845 SR |
891 | { |
892 | if (prev_class != p->sched_class) { | |
893 | if (prev_class->switched_from) | |
da7a735e PZ |
894 | prev_class->switched_from(rq, p); |
895 | p->sched_class->switched_to(rq, p); | |
896 | } else if (oldprio != p->prio) | |
897 | p->sched_class->prio_changed(rq, p, oldprio); | |
cb469845 SR |
898 | } |
899 | ||
029632fb | 900 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
1e5a7405 PZ |
901 | { |
902 | const struct sched_class *class; | |
903 | ||
904 | if (p->sched_class == rq->curr->sched_class) { | |
905 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
906 | } else { | |
907 | for_each_class(class) { | |
908 | if (class == rq->curr->sched_class) | |
909 | break; | |
910 | if (class == p->sched_class) { | |
911 | resched_task(rq->curr); | |
912 | break; | |
913 | } | |
914 | } | |
915 | } | |
916 | ||
917 | /* | |
918 | * A queue event has occurred, and we're going to schedule. In | |
919 | * this case, we can save a useless back to back clock update. | |
920 | */ | |
fd2f4419 | 921 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
922 | rq->skip_clock_update = 1; |
923 | } | |
924 | ||
1da177e4 | 925 | #ifdef CONFIG_SMP |
dd41f596 | 926 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 927 | { |
e2912009 PZ |
928 | #ifdef CONFIG_SCHED_DEBUG |
929 | /* | |
930 | * We should never call set_task_cpu() on a blocked task, | |
931 | * ttwu() will sort out the placement. | |
932 | */ | |
077614ee PZ |
933 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
934 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
0122ec5b PZ |
935 | |
936 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
937 | /* |
938 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
939 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
940 | * | |
941 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
8323f26c | 942 | * see task_group(). |
6c6c54e1 PZ |
943 | * |
944 | * Furthermore, all task_rq users should acquire both locks, see | |
945 | * task_rq_lock(). | |
946 | */ | |
0122ec5b PZ |
947 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
948 | lockdep_is_held(&task_rq(p)->lock))); | |
949 | #endif | |
e2912009 PZ |
950 | #endif |
951 | ||
de1d7286 | 952 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 953 | |
0c69774e PZ |
954 | if (task_cpu(p) != new_cpu) { |
955 | p->se.nr_migrations++; | |
a8b0ca17 | 956 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 957 | } |
dd41f596 IM |
958 | |
959 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
960 | } |
961 | ||
969c7921 | 962 | struct migration_arg { |
36c8b586 | 963 | struct task_struct *task; |
1da177e4 | 964 | int dest_cpu; |
70b97a7f | 965 | }; |
1da177e4 | 966 | |
969c7921 TH |
967 | static int migration_cpu_stop(void *data); |
968 | ||
1da177e4 LT |
969 | /* |
970 | * wait_task_inactive - wait for a thread to unschedule. | |
971 | * | |
85ba2d86 RM |
972 | * If @match_state is nonzero, it's the @p->state value just checked and |
973 | * not expected to change. If it changes, i.e. @p might have woken up, | |
974 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
975 | * we return a positive number (its total switch count). If a second call | |
976 | * a short while later returns the same number, the caller can be sure that | |
977 | * @p has remained unscheduled the whole time. | |
978 | * | |
1da177e4 LT |
979 | * The caller must ensure that the task *will* unschedule sometime soon, |
980 | * else this function might spin for a *long* time. This function can't | |
981 | * be called with interrupts off, or it may introduce deadlock with | |
982 | * smp_call_function() if an IPI is sent by the same process we are | |
983 | * waiting to become inactive. | |
984 | */ | |
85ba2d86 | 985 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
986 | { |
987 | unsigned long flags; | |
dd41f596 | 988 | int running, on_rq; |
85ba2d86 | 989 | unsigned long ncsw; |
70b97a7f | 990 | struct rq *rq; |
1da177e4 | 991 | |
3a5c359a AK |
992 | for (;;) { |
993 | /* | |
994 | * We do the initial early heuristics without holding | |
995 | * any task-queue locks at all. We'll only try to get | |
996 | * the runqueue lock when things look like they will | |
997 | * work out! | |
998 | */ | |
999 | rq = task_rq(p); | |
fa490cfd | 1000 | |
3a5c359a AK |
1001 | /* |
1002 | * If the task is actively running on another CPU | |
1003 | * still, just relax and busy-wait without holding | |
1004 | * any locks. | |
1005 | * | |
1006 | * NOTE! Since we don't hold any locks, it's not | |
1007 | * even sure that "rq" stays as the right runqueue! | |
1008 | * But we don't care, since "task_running()" will | |
1009 | * return false if the runqueue has changed and p | |
1010 | * is actually now running somewhere else! | |
1011 | */ | |
85ba2d86 RM |
1012 | while (task_running(rq, p)) { |
1013 | if (match_state && unlikely(p->state != match_state)) | |
1014 | return 0; | |
3a5c359a | 1015 | cpu_relax(); |
85ba2d86 | 1016 | } |
fa490cfd | 1017 | |
3a5c359a AK |
1018 | /* |
1019 | * Ok, time to look more closely! We need the rq | |
1020 | * lock now, to be *sure*. If we're wrong, we'll | |
1021 | * just go back and repeat. | |
1022 | */ | |
1023 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 1024 | trace_sched_wait_task(p); |
3a5c359a | 1025 | running = task_running(rq, p); |
fd2f4419 | 1026 | on_rq = p->on_rq; |
85ba2d86 | 1027 | ncsw = 0; |
f31e11d8 | 1028 | if (!match_state || p->state == match_state) |
93dcf55f | 1029 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 1030 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 1031 | |
85ba2d86 RM |
1032 | /* |
1033 | * If it changed from the expected state, bail out now. | |
1034 | */ | |
1035 | if (unlikely(!ncsw)) | |
1036 | break; | |
1037 | ||
3a5c359a AK |
1038 | /* |
1039 | * Was it really running after all now that we | |
1040 | * checked with the proper locks actually held? | |
1041 | * | |
1042 | * Oops. Go back and try again.. | |
1043 | */ | |
1044 | if (unlikely(running)) { | |
1045 | cpu_relax(); | |
1046 | continue; | |
1047 | } | |
fa490cfd | 1048 | |
3a5c359a AK |
1049 | /* |
1050 | * It's not enough that it's not actively running, | |
1051 | * it must be off the runqueue _entirely_, and not | |
1052 | * preempted! | |
1053 | * | |
80dd99b3 | 1054 | * So if it was still runnable (but just not actively |
3a5c359a AK |
1055 | * running right now), it's preempted, and we should |
1056 | * yield - it could be a while. | |
1057 | */ | |
1058 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
1059 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
1060 | ||
1061 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1062 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
1063 | continue; |
1064 | } | |
fa490cfd | 1065 | |
3a5c359a AK |
1066 | /* |
1067 | * Ahh, all good. It wasn't running, and it wasn't | |
1068 | * runnable, which means that it will never become | |
1069 | * running in the future either. We're all done! | |
1070 | */ | |
1071 | break; | |
1072 | } | |
85ba2d86 RM |
1073 | |
1074 | return ncsw; | |
1da177e4 LT |
1075 | } |
1076 | ||
1077 | /*** | |
1078 | * kick_process - kick a running thread to enter/exit the kernel | |
1079 | * @p: the to-be-kicked thread | |
1080 | * | |
1081 | * Cause a process which is running on another CPU to enter | |
1082 | * kernel-mode, without any delay. (to get signals handled.) | |
1083 | * | |
25985edc | 1084 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
1085 | * because all it wants to ensure is that the remote task enters |
1086 | * the kernel. If the IPI races and the task has been migrated | |
1087 | * to another CPU then no harm is done and the purpose has been | |
1088 | * achieved as well. | |
1089 | */ | |
36c8b586 | 1090 | void kick_process(struct task_struct *p) |
1da177e4 LT |
1091 | { |
1092 | int cpu; | |
1093 | ||
1094 | preempt_disable(); | |
1095 | cpu = task_cpu(p); | |
1096 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
1097 | smp_send_reschedule(cpu); | |
1098 | preempt_enable(); | |
1099 | } | |
b43e3521 | 1100 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 1101 | #endif /* CONFIG_SMP */ |
1da177e4 | 1102 | |
970b13ba | 1103 | #ifdef CONFIG_SMP |
30da688e | 1104 | /* |
013fdb80 | 1105 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 1106 | */ |
5da9a0fb PZ |
1107 | static int select_fallback_rq(int cpu, struct task_struct *p) |
1108 | { | |
5da9a0fb | 1109 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); |
2baab4e9 PZ |
1110 | enum { cpuset, possible, fail } state = cpuset; |
1111 | int dest_cpu; | |
5da9a0fb PZ |
1112 | |
1113 | /* Look for allowed, online CPU in same node. */ | |
e3831edd | 1114 | for_each_cpu(dest_cpu, nodemask) { |
2baab4e9 PZ |
1115 | if (!cpu_online(dest_cpu)) |
1116 | continue; | |
1117 | if (!cpu_active(dest_cpu)) | |
1118 | continue; | |
fa17b507 | 1119 | if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
5da9a0fb | 1120 | return dest_cpu; |
2baab4e9 | 1121 | } |
5da9a0fb | 1122 | |
2baab4e9 PZ |
1123 | for (;;) { |
1124 | /* Any allowed, online CPU? */ | |
e3831edd | 1125 | for_each_cpu(dest_cpu, tsk_cpus_allowed(p)) { |
2baab4e9 PZ |
1126 | if (!cpu_online(dest_cpu)) |
1127 | continue; | |
1128 | if (!cpu_active(dest_cpu)) | |
1129 | continue; | |
1130 | goto out; | |
1131 | } | |
5da9a0fb | 1132 | |
2baab4e9 PZ |
1133 | switch (state) { |
1134 | case cpuset: | |
1135 | /* No more Mr. Nice Guy. */ | |
1136 | cpuset_cpus_allowed_fallback(p); | |
1137 | state = possible; | |
1138 | break; | |
1139 | ||
1140 | case possible: | |
1141 | do_set_cpus_allowed(p, cpu_possible_mask); | |
1142 | state = fail; | |
1143 | break; | |
1144 | ||
1145 | case fail: | |
1146 | BUG(); | |
1147 | break; | |
1148 | } | |
1149 | } | |
1150 | ||
1151 | out: | |
1152 | if (state != cpuset) { | |
1153 | /* | |
1154 | * Don't tell them about moving exiting tasks or | |
1155 | * kernel threads (both mm NULL), since they never | |
1156 | * leave kernel. | |
1157 | */ | |
1158 | if (p->mm && printk_ratelimit()) { | |
1159 | printk_sched("process %d (%s) no longer affine to cpu%d\n", | |
1160 | task_pid_nr(p), p->comm, cpu); | |
1161 | } | |
5da9a0fb PZ |
1162 | } |
1163 | ||
1164 | return dest_cpu; | |
1165 | } | |
1166 | ||
e2912009 | 1167 | /* |
013fdb80 | 1168 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 1169 | */ |
970b13ba | 1170 | static inline |
7608dec2 | 1171 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 1172 | { |
7608dec2 | 1173 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
e2912009 PZ |
1174 | |
1175 | /* | |
1176 | * In order not to call set_task_cpu() on a blocking task we need | |
1177 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
1178 | * cpu. | |
1179 | * | |
1180 | * Since this is common to all placement strategies, this lives here. | |
1181 | * | |
1182 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
1183 | * not worry about this generic constraint ] | |
1184 | */ | |
fa17b507 | 1185 | if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || |
70f11205 | 1186 | !cpu_online(cpu))) |
5da9a0fb | 1187 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
1188 | |
1189 | return cpu; | |
970b13ba | 1190 | } |
09a40af5 MG |
1191 | |
1192 | static void update_avg(u64 *avg, u64 sample) | |
1193 | { | |
1194 | s64 diff = sample - *avg; | |
1195 | *avg += diff >> 3; | |
1196 | } | |
970b13ba PZ |
1197 | #endif |
1198 | ||
d7c01d27 | 1199 | static void |
b84cb5df | 1200 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 1201 | { |
d7c01d27 | 1202 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
1203 | struct rq *rq = this_rq(); |
1204 | ||
d7c01d27 PZ |
1205 | #ifdef CONFIG_SMP |
1206 | int this_cpu = smp_processor_id(); | |
1207 | ||
1208 | if (cpu == this_cpu) { | |
1209 | schedstat_inc(rq, ttwu_local); | |
1210 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
1211 | } else { | |
1212 | struct sched_domain *sd; | |
1213 | ||
1214 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 1215 | rcu_read_lock(); |
d7c01d27 PZ |
1216 | for_each_domain(this_cpu, sd) { |
1217 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
1218 | schedstat_inc(sd, ttwu_wake_remote); | |
1219 | break; | |
1220 | } | |
1221 | } | |
057f3fad | 1222 | rcu_read_unlock(); |
d7c01d27 | 1223 | } |
f339b9dc PZ |
1224 | |
1225 | if (wake_flags & WF_MIGRATED) | |
1226 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
1227 | ||
d7c01d27 PZ |
1228 | #endif /* CONFIG_SMP */ |
1229 | ||
1230 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 1231 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
1232 | |
1233 | if (wake_flags & WF_SYNC) | |
9ed3811a | 1234 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 1235 | |
d7c01d27 PZ |
1236 | #endif /* CONFIG_SCHEDSTATS */ |
1237 | } | |
1238 | ||
1239 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
1240 | { | |
9ed3811a | 1241 | activate_task(rq, p, en_flags); |
fd2f4419 | 1242 | p->on_rq = 1; |
c2f7115e PZ |
1243 | |
1244 | /* if a worker is waking up, notify workqueue */ | |
1245 | if (p->flags & PF_WQ_WORKER) | |
1246 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
1247 | } |
1248 | ||
23f41eeb PZ |
1249 | /* |
1250 | * Mark the task runnable and perform wakeup-preemption. | |
1251 | */ | |
89363381 | 1252 | static void |
23f41eeb | 1253 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 1254 | { |
89363381 | 1255 | trace_sched_wakeup(p, true); |
9ed3811a TH |
1256 | check_preempt_curr(rq, p, wake_flags); |
1257 | ||
1258 | p->state = TASK_RUNNING; | |
1259 | #ifdef CONFIG_SMP | |
1260 | if (p->sched_class->task_woken) | |
1261 | p->sched_class->task_woken(rq, p); | |
1262 | ||
e69c6341 | 1263 | if (rq->idle_stamp) { |
9ed3811a TH |
1264 | u64 delta = rq->clock - rq->idle_stamp; |
1265 | u64 max = 2*sysctl_sched_migration_cost; | |
1266 | ||
1267 | if (delta > max) | |
1268 | rq->avg_idle = max; | |
1269 | else | |
1270 | update_avg(&rq->avg_idle, delta); | |
1271 | rq->idle_stamp = 0; | |
1272 | } | |
1273 | #endif | |
1274 | } | |
1275 | ||
c05fbafb PZ |
1276 | static void |
1277 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
1278 | { | |
1279 | #ifdef CONFIG_SMP | |
1280 | if (p->sched_contributes_to_load) | |
1281 | rq->nr_uninterruptible--; | |
1282 | #endif | |
1283 | ||
1284 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
1285 | ttwu_do_wakeup(rq, p, wake_flags); | |
1286 | } | |
1287 | ||
1288 | /* | |
1289 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
1290 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
1291 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
1292 | * the task is still ->on_rq. | |
1293 | */ | |
1294 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
1295 | { | |
1296 | struct rq *rq; | |
1297 | int ret = 0; | |
1298 | ||
1299 | rq = __task_rq_lock(p); | |
1300 | if (p->on_rq) { | |
1301 | ttwu_do_wakeup(rq, p, wake_flags); | |
1302 | ret = 1; | |
1303 | } | |
1304 | __task_rq_unlock(rq); | |
1305 | ||
1306 | return ret; | |
1307 | } | |
1308 | ||
317f3941 | 1309 | #ifdef CONFIG_SMP |
fa14ff4a | 1310 | static void sched_ttwu_pending(void) |
317f3941 PZ |
1311 | { |
1312 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
1313 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
1314 | struct task_struct *p; | |
317f3941 PZ |
1315 | |
1316 | raw_spin_lock(&rq->lock); | |
1317 | ||
fa14ff4a PZ |
1318 | while (llist) { |
1319 | p = llist_entry(llist, struct task_struct, wake_entry); | |
1320 | llist = llist_next(llist); | |
317f3941 PZ |
1321 | ttwu_do_activate(rq, p, 0); |
1322 | } | |
1323 | ||
1324 | raw_spin_unlock(&rq->lock); | |
1325 | } | |
1326 | ||
1327 | void scheduler_ipi(void) | |
1328 | { | |
ca38062e | 1329 | if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) |
c5d753a5 PZ |
1330 | return; |
1331 | ||
1332 | /* | |
1333 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
1334 | * traditionally all their work was done from the interrupt return | |
1335 | * path. Now that we actually do some work, we need to make sure | |
1336 | * we do call them. | |
1337 | * | |
1338 | * Some archs already do call them, luckily irq_enter/exit nest | |
1339 | * properly. | |
1340 | * | |
1341 | * Arguably we should visit all archs and update all handlers, | |
1342 | * however a fair share of IPIs are still resched only so this would | |
1343 | * somewhat pessimize the simple resched case. | |
1344 | */ | |
1345 | irq_enter(); | |
fa14ff4a | 1346 | sched_ttwu_pending(); |
ca38062e SS |
1347 | |
1348 | /* | |
1349 | * Check if someone kicked us for doing the nohz idle load balance. | |
1350 | */ | |
6eb57e0d SS |
1351 | if (unlikely(got_nohz_idle_kick() && !need_resched())) { |
1352 | this_rq()->idle_balance = 1; | |
ca38062e | 1353 | raise_softirq_irqoff(SCHED_SOFTIRQ); |
6eb57e0d | 1354 | } |
c5d753a5 | 1355 | irq_exit(); |
317f3941 PZ |
1356 | } |
1357 | ||
1358 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
1359 | { | |
fa14ff4a | 1360 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) |
317f3941 PZ |
1361 | smp_send_reschedule(cpu); |
1362 | } | |
d6aa8f85 | 1363 | |
39be3501 | 1364 | bool cpus_share_cache(int this_cpu, int that_cpu) |
518cd623 PZ |
1365 | { |
1366 | return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); | |
1367 | } | |
d6aa8f85 | 1368 | #endif /* CONFIG_SMP */ |
317f3941 | 1369 | |
c05fbafb PZ |
1370 | static void ttwu_queue(struct task_struct *p, int cpu) |
1371 | { | |
1372 | struct rq *rq = cpu_rq(cpu); | |
1373 | ||
17d9f311 | 1374 | #if defined(CONFIG_SMP) |
39be3501 | 1375 | if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) { |
f01114cb | 1376 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
1377 | ttwu_queue_remote(p, cpu); |
1378 | return; | |
1379 | } | |
1380 | #endif | |
1381 | ||
c05fbafb PZ |
1382 | raw_spin_lock(&rq->lock); |
1383 | ttwu_do_activate(rq, p, 0); | |
1384 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
1385 | } |
1386 | ||
1387 | /** | |
1da177e4 | 1388 | * try_to_wake_up - wake up a thread |
9ed3811a | 1389 | * @p: the thread to be awakened |
1da177e4 | 1390 | * @state: the mask of task states that can be woken |
9ed3811a | 1391 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
1392 | * |
1393 | * Put it on the run-queue if it's not already there. The "current" | |
1394 | * thread is always on the run-queue (except when the actual | |
1395 | * re-schedule is in progress), and as such you're allowed to do | |
1396 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
1397 | * runnable without the overhead of this. | |
1398 | * | |
9ed3811a TH |
1399 | * Returns %true if @p was woken up, %false if it was already running |
1400 | * or @state didn't match @p's state. | |
1da177e4 | 1401 | */ |
e4a52bcb PZ |
1402 | static int |
1403 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 1404 | { |
1da177e4 | 1405 | unsigned long flags; |
c05fbafb | 1406 | int cpu, success = 0; |
2398f2c6 | 1407 | |
04e2f174 | 1408 | smp_wmb(); |
013fdb80 | 1409 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 1410 | if (!(p->state & state)) |
1da177e4 LT |
1411 | goto out; |
1412 | ||
c05fbafb | 1413 | success = 1; /* we're going to change ->state */ |
1da177e4 | 1414 | cpu = task_cpu(p); |
1da177e4 | 1415 | |
c05fbafb PZ |
1416 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
1417 | goto stat; | |
1da177e4 | 1418 | |
1da177e4 | 1419 | #ifdef CONFIG_SMP |
e9c84311 | 1420 | /* |
c05fbafb PZ |
1421 | * If the owning (remote) cpu is still in the middle of schedule() with |
1422 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 1423 | */ |
f3e94786 | 1424 | while (p->on_cpu) |
e4a52bcb | 1425 | cpu_relax(); |
0970d299 | 1426 | /* |
e4a52bcb | 1427 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 1428 | */ |
e4a52bcb | 1429 | smp_rmb(); |
1da177e4 | 1430 | |
a8e4f2ea | 1431 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 1432 | p->state = TASK_WAKING; |
e7693a36 | 1433 | |
e4a52bcb | 1434 | if (p->sched_class->task_waking) |
74f8e4b2 | 1435 | p->sched_class->task_waking(p); |
efbbd05a | 1436 | |
7608dec2 | 1437 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
1438 | if (task_cpu(p) != cpu) { |
1439 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 1440 | set_task_cpu(p, cpu); |
f339b9dc | 1441 | } |
1da177e4 | 1442 | #endif /* CONFIG_SMP */ |
1da177e4 | 1443 | |
c05fbafb PZ |
1444 | ttwu_queue(p, cpu); |
1445 | stat: | |
b84cb5df | 1446 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 1447 | out: |
013fdb80 | 1448 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
1449 | |
1450 | return success; | |
1451 | } | |
1452 | ||
21aa9af0 TH |
1453 | /** |
1454 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
1455 | * @p: the thread to be awakened | |
1456 | * | |
2acca55e | 1457 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 1458 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 1459 | * the current task. |
21aa9af0 TH |
1460 | */ |
1461 | static void try_to_wake_up_local(struct task_struct *p) | |
1462 | { | |
1463 | struct rq *rq = task_rq(p); | |
21aa9af0 TH |
1464 | |
1465 | BUG_ON(rq != this_rq()); | |
1466 | BUG_ON(p == current); | |
1467 | lockdep_assert_held(&rq->lock); | |
1468 | ||
2acca55e PZ |
1469 | if (!raw_spin_trylock(&p->pi_lock)) { |
1470 | raw_spin_unlock(&rq->lock); | |
1471 | raw_spin_lock(&p->pi_lock); | |
1472 | raw_spin_lock(&rq->lock); | |
1473 | } | |
1474 | ||
21aa9af0 | 1475 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 1476 | goto out; |
21aa9af0 | 1477 | |
fd2f4419 | 1478 | if (!p->on_rq) |
d7c01d27 PZ |
1479 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
1480 | ||
23f41eeb | 1481 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 1482 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
1483 | out: |
1484 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
1485 | } |
1486 | ||
50fa610a DH |
1487 | /** |
1488 | * wake_up_process - Wake up a specific process | |
1489 | * @p: The process to be woken up. | |
1490 | * | |
1491 | * Attempt to wake up the nominated process and move it to the set of runnable | |
1492 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
1493 | * running. | |
1494 | * | |
1495 | * It may be assumed that this function implies a write memory barrier before | |
1496 | * changing the task state if and only if any tasks are woken up. | |
1497 | */ | |
7ad5b3a5 | 1498 | int wake_up_process(struct task_struct *p) |
1da177e4 | 1499 | { |
d9514f6c | 1500 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 1501 | } |
1da177e4 LT |
1502 | EXPORT_SYMBOL(wake_up_process); |
1503 | ||
7ad5b3a5 | 1504 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
1505 | { |
1506 | return try_to_wake_up(p, state, 0); | |
1507 | } | |
1508 | ||
1da177e4 LT |
1509 | /* |
1510 | * Perform scheduler related setup for a newly forked process p. | |
1511 | * p is forked by current. | |
dd41f596 IM |
1512 | * |
1513 | * __sched_fork() is basic setup used by init_idle() too: | |
1514 | */ | |
1515 | static void __sched_fork(struct task_struct *p) | |
1516 | { | |
fd2f4419 PZ |
1517 | p->on_rq = 0; |
1518 | ||
1519 | p->se.on_rq = 0; | |
dd41f596 IM |
1520 | p->se.exec_start = 0; |
1521 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 1522 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 1523 | p->se.nr_migrations = 0; |
da7a735e | 1524 | p->se.vruntime = 0; |
fd2f4419 | 1525 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
1526 | |
1527 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 1528 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 1529 | #endif |
476d139c | 1530 | |
fa717060 | 1531 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 1532 | |
e107be36 AK |
1533 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1534 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
1535 | #endif | |
dd41f596 IM |
1536 | } |
1537 | ||
1538 | /* | |
1539 | * fork()/clone()-time setup: | |
1540 | */ | |
3e51e3ed | 1541 | void sched_fork(struct task_struct *p) |
dd41f596 | 1542 | { |
0122ec5b | 1543 | unsigned long flags; |
dd41f596 IM |
1544 | int cpu = get_cpu(); |
1545 | ||
1546 | __sched_fork(p); | |
06b83b5f | 1547 | /* |
0017d735 | 1548 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
1549 | * nobody will actually run it, and a signal or other external |
1550 | * event cannot wake it up and insert it on the runqueue either. | |
1551 | */ | |
0017d735 | 1552 | p->state = TASK_RUNNING; |
dd41f596 | 1553 | |
c350a04e MG |
1554 | /* |
1555 | * Make sure we do not leak PI boosting priority to the child. | |
1556 | */ | |
1557 | p->prio = current->normal_prio; | |
1558 | ||
b9dc29e7 MG |
1559 | /* |
1560 | * Revert to default priority/policy on fork if requested. | |
1561 | */ | |
1562 | if (unlikely(p->sched_reset_on_fork)) { | |
c350a04e | 1563 | if (task_has_rt_policy(p)) { |
b9dc29e7 | 1564 | p->policy = SCHED_NORMAL; |
6c697bdf | 1565 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
1566 | p->rt_priority = 0; |
1567 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
1568 | p->static_prio = NICE_TO_PRIO(0); | |
1569 | ||
1570 | p->prio = p->normal_prio = __normal_prio(p); | |
1571 | set_load_weight(p); | |
6c697bdf | 1572 | |
b9dc29e7 MG |
1573 | /* |
1574 | * We don't need the reset flag anymore after the fork. It has | |
1575 | * fulfilled its duty: | |
1576 | */ | |
1577 | p->sched_reset_on_fork = 0; | |
1578 | } | |
ca94c442 | 1579 | |
2ddbf952 HS |
1580 | if (!rt_prio(p->prio)) |
1581 | p->sched_class = &fair_sched_class; | |
b29739f9 | 1582 | |
cd29fe6f PZ |
1583 | if (p->sched_class->task_fork) |
1584 | p->sched_class->task_fork(p); | |
1585 | ||
86951599 PZ |
1586 | /* |
1587 | * The child is not yet in the pid-hash so no cgroup attach races, | |
1588 | * and the cgroup is pinned to this child due to cgroup_fork() | |
1589 | * is ran before sched_fork(). | |
1590 | * | |
1591 | * Silence PROVE_RCU. | |
1592 | */ | |
0122ec5b | 1593 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 1594 | set_task_cpu(p, cpu); |
0122ec5b | 1595 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 1596 | |
52f17b6c | 1597 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 1598 | if (likely(sched_info_on())) |
52f17b6c | 1599 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 1600 | #endif |
3ca7a440 PZ |
1601 | #if defined(CONFIG_SMP) |
1602 | p->on_cpu = 0; | |
4866cde0 | 1603 | #endif |
bdd4e85d | 1604 | #ifdef CONFIG_PREEMPT_COUNT |
4866cde0 | 1605 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 1606 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 1607 | #endif |
806c09a7 | 1608 | #ifdef CONFIG_SMP |
917b627d | 1609 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
806c09a7 | 1610 | #endif |
917b627d | 1611 | |
476d139c | 1612 | put_cpu(); |
1da177e4 LT |
1613 | } |
1614 | ||
1615 | /* | |
1616 | * wake_up_new_task - wake up a newly created task for the first time. | |
1617 | * | |
1618 | * This function will do some initial scheduler statistics housekeeping | |
1619 | * that must be done for every newly created context, then puts the task | |
1620 | * on the runqueue and wakes it. | |
1621 | */ | |
3e51e3ed | 1622 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
1623 | { |
1624 | unsigned long flags; | |
dd41f596 | 1625 | struct rq *rq; |
fabf318e | 1626 | |
ab2515c4 | 1627 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
1628 | #ifdef CONFIG_SMP |
1629 | /* | |
1630 | * Fork balancing, do it here and not earlier because: | |
1631 | * - cpus_allowed can change in the fork path | |
1632 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 1633 | */ |
ab2515c4 | 1634 | set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); |
0017d735 PZ |
1635 | #endif |
1636 | ||
ab2515c4 | 1637 | rq = __task_rq_lock(p); |
cd29fe6f | 1638 | activate_task(rq, p, 0); |
fd2f4419 | 1639 | p->on_rq = 1; |
89363381 | 1640 | trace_sched_wakeup_new(p, true); |
a7558e01 | 1641 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 1642 | #ifdef CONFIG_SMP |
efbbd05a PZ |
1643 | if (p->sched_class->task_woken) |
1644 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 1645 | #endif |
0122ec5b | 1646 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
1647 | } |
1648 | ||
e107be36 AK |
1649 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1650 | ||
1651 | /** | |
80dd99b3 | 1652 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 1653 | * @notifier: notifier struct to register |
e107be36 AK |
1654 | */ |
1655 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
1656 | { | |
1657 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
1658 | } | |
1659 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
1660 | ||
1661 | /** | |
1662 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 1663 | * @notifier: notifier struct to unregister |
e107be36 AK |
1664 | * |
1665 | * This is safe to call from within a preemption notifier. | |
1666 | */ | |
1667 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
1668 | { | |
1669 | hlist_del(¬ifier->link); | |
1670 | } | |
1671 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
1672 | ||
1673 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
1674 | { | |
1675 | struct preempt_notifier *notifier; | |
1676 | struct hlist_node *node; | |
1677 | ||
1678 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
1679 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
1680 | } | |
1681 | ||
1682 | static void | |
1683 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
1684 | struct task_struct *next) | |
1685 | { | |
1686 | struct preempt_notifier *notifier; | |
1687 | struct hlist_node *node; | |
1688 | ||
1689 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
1690 | notifier->ops->sched_out(notifier, next); | |
1691 | } | |
1692 | ||
6d6bc0ad | 1693 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
1694 | |
1695 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
1696 | { | |
1697 | } | |
1698 | ||
1699 | static void | |
1700 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
1701 | struct task_struct *next) | |
1702 | { | |
1703 | } | |
1704 | ||
6d6bc0ad | 1705 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 1706 | |
4866cde0 NP |
1707 | /** |
1708 | * prepare_task_switch - prepare to switch tasks | |
1709 | * @rq: the runqueue preparing to switch | |
421cee29 | 1710 | * @prev: the current task that is being switched out |
4866cde0 NP |
1711 | * @next: the task we are going to switch to. |
1712 | * | |
1713 | * This is called with the rq lock held and interrupts off. It must | |
1714 | * be paired with a subsequent finish_task_switch after the context | |
1715 | * switch. | |
1716 | * | |
1717 | * prepare_task_switch sets up locking and calls architecture specific | |
1718 | * hooks. | |
1719 | */ | |
e107be36 AK |
1720 | static inline void |
1721 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
1722 | struct task_struct *next) | |
4866cde0 | 1723 | { |
895dd92c | 1724 | trace_sched_switch(prev, next); |
fe4b04fa PZ |
1725 | sched_info_switch(prev, next); |
1726 | perf_event_task_sched_out(prev, next); | |
e107be36 | 1727 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
1728 | prepare_lock_switch(rq, next); |
1729 | prepare_arch_switch(next); | |
1730 | } | |
1731 | ||
1da177e4 LT |
1732 | /** |
1733 | * finish_task_switch - clean up after a task-switch | |
344babaa | 1734 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
1735 | * @prev: the thread we just switched away from. |
1736 | * | |
4866cde0 NP |
1737 | * finish_task_switch must be called after the context switch, paired |
1738 | * with a prepare_task_switch call before the context switch. | |
1739 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
1740 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
1741 | * |
1742 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 1743 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
1744 | * with the lock held can cause deadlocks; see schedule() for |
1745 | * details.) | |
1746 | */ | |
a9957449 | 1747 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
1748 | __releases(rq->lock) |
1749 | { | |
1da177e4 | 1750 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 1751 | long prev_state; |
1da177e4 LT |
1752 | |
1753 | rq->prev_mm = NULL; | |
1754 | ||
1755 | /* | |
1756 | * A task struct has one reference for the use as "current". | |
c394cc9f | 1757 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
1758 | * schedule one last time. The schedule call will never return, and |
1759 | * the scheduled task must drop that reference. | |
c394cc9f | 1760 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
1761 | * still held, otherwise prev could be scheduled on another cpu, die |
1762 | * there before we look at prev->state, and then the reference would | |
1763 | * be dropped twice. | |
1764 | * Manfred Spraul <manfred@colorfullife.com> | |
1765 | */ | |
55a101f8 | 1766 | prev_state = prev->state; |
bf9fae9f | 1767 | vtime_task_switch(prev); |
4866cde0 | 1768 | finish_arch_switch(prev); |
a8d757ef | 1769 | perf_event_task_sched_in(prev, current); |
4866cde0 | 1770 | finish_lock_switch(rq, prev); |
01f23e16 | 1771 | finish_arch_post_lock_switch(); |
e8fa1362 | 1772 | |
e107be36 | 1773 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
1774 | if (mm) |
1775 | mmdrop(mm); | |
c394cc9f | 1776 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 1777 | /* |
1778 | * Remove function-return probe instances associated with this | |
1779 | * task and put them back on the free list. | |
9761eea8 | 1780 | */ |
c6fd91f0 | 1781 | kprobe_flush_task(prev); |
1da177e4 | 1782 | put_task_struct(prev); |
c6fd91f0 | 1783 | } |
1da177e4 LT |
1784 | } |
1785 | ||
3f029d3c GH |
1786 | #ifdef CONFIG_SMP |
1787 | ||
1788 | /* assumes rq->lock is held */ | |
1789 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
1790 | { | |
1791 | if (prev->sched_class->pre_schedule) | |
1792 | prev->sched_class->pre_schedule(rq, prev); | |
1793 | } | |
1794 | ||
1795 | /* rq->lock is NOT held, but preemption is disabled */ | |
1796 | static inline void post_schedule(struct rq *rq) | |
1797 | { | |
1798 | if (rq->post_schedule) { | |
1799 | unsigned long flags; | |
1800 | ||
05fa785c | 1801 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
1802 | if (rq->curr->sched_class->post_schedule) |
1803 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 1804 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
1805 | |
1806 | rq->post_schedule = 0; | |
1807 | } | |
1808 | } | |
1809 | ||
1810 | #else | |
da19ab51 | 1811 | |
3f029d3c GH |
1812 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
1813 | { | |
1814 | } | |
1815 | ||
1816 | static inline void post_schedule(struct rq *rq) | |
1817 | { | |
1da177e4 LT |
1818 | } |
1819 | ||
3f029d3c GH |
1820 | #endif |
1821 | ||
1da177e4 LT |
1822 | /** |
1823 | * schedule_tail - first thing a freshly forked thread must call. | |
1824 | * @prev: the thread we just switched away from. | |
1825 | */ | |
36c8b586 | 1826 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
1827 | __releases(rq->lock) |
1828 | { | |
70b97a7f IM |
1829 | struct rq *rq = this_rq(); |
1830 | ||
4866cde0 | 1831 | finish_task_switch(rq, prev); |
da19ab51 | 1832 | |
3f029d3c GH |
1833 | /* |
1834 | * FIXME: do we need to worry about rq being invalidated by the | |
1835 | * task_switch? | |
1836 | */ | |
1837 | post_schedule(rq); | |
70b97a7f | 1838 | |
4866cde0 NP |
1839 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
1840 | /* In this case, finish_task_switch does not reenable preemption */ | |
1841 | preempt_enable(); | |
1842 | #endif | |
1da177e4 | 1843 | if (current->set_child_tid) |
b488893a | 1844 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
1845 | } |
1846 | ||
1847 | /* | |
1848 | * context_switch - switch to the new MM and the new | |
1849 | * thread's register state. | |
1850 | */ | |
dd41f596 | 1851 | static inline void |
70b97a7f | 1852 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 1853 | struct task_struct *next) |
1da177e4 | 1854 | { |
dd41f596 | 1855 | struct mm_struct *mm, *oldmm; |
1da177e4 | 1856 | |
e107be36 | 1857 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 1858 | |
dd41f596 IM |
1859 | mm = next->mm; |
1860 | oldmm = prev->active_mm; | |
9226d125 ZA |
1861 | /* |
1862 | * For paravirt, this is coupled with an exit in switch_to to | |
1863 | * combine the page table reload and the switch backend into | |
1864 | * one hypercall. | |
1865 | */ | |
224101ed | 1866 | arch_start_context_switch(prev); |
9226d125 | 1867 | |
31915ab4 | 1868 | if (!mm) { |
1da177e4 LT |
1869 | next->active_mm = oldmm; |
1870 | atomic_inc(&oldmm->mm_count); | |
1871 | enter_lazy_tlb(oldmm, next); | |
1872 | } else | |
1873 | switch_mm(oldmm, mm, next); | |
1874 | ||
31915ab4 | 1875 | if (!prev->mm) { |
1da177e4 | 1876 | prev->active_mm = NULL; |
1da177e4 LT |
1877 | rq->prev_mm = oldmm; |
1878 | } | |
3a5f5e48 IM |
1879 | /* |
1880 | * Since the runqueue lock will be released by the next | |
1881 | * task (which is an invalid locking op but in the case | |
1882 | * of the scheduler it's an obvious special-case), so we | |
1883 | * do an early lockdep release here: | |
1884 | */ | |
1885 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 1886 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 1887 | #endif |
1da177e4 LT |
1888 | |
1889 | /* Here we just switch the register state and the stack. */ | |
04e7e951 | 1890 | rcu_switch(prev, next); |
1da177e4 LT |
1891 | switch_to(prev, next, prev); |
1892 | ||
dd41f596 IM |
1893 | barrier(); |
1894 | /* | |
1895 | * this_rq must be evaluated again because prev may have moved | |
1896 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
1897 | * frame will be invalid. | |
1898 | */ | |
1899 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
1900 | } |
1901 | ||
1902 | /* | |
1903 | * nr_running, nr_uninterruptible and nr_context_switches: | |
1904 | * | |
1905 | * externally visible scheduler statistics: current number of runnable | |
1906 | * threads, current number of uninterruptible-sleeping threads, total | |
1907 | * number of context switches performed since bootup. | |
1908 | */ | |
1909 | unsigned long nr_running(void) | |
1910 | { | |
1911 | unsigned long i, sum = 0; | |
1912 | ||
1913 | for_each_online_cpu(i) | |
1914 | sum += cpu_rq(i)->nr_running; | |
1915 | ||
1916 | return sum; | |
f711f609 | 1917 | } |
1da177e4 LT |
1918 | |
1919 | unsigned long nr_uninterruptible(void) | |
f711f609 | 1920 | { |
1da177e4 | 1921 | unsigned long i, sum = 0; |
f711f609 | 1922 | |
0a945022 | 1923 | for_each_possible_cpu(i) |
1da177e4 | 1924 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
1925 | |
1926 | /* | |
1da177e4 LT |
1927 | * Since we read the counters lockless, it might be slightly |
1928 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 1929 | */ |
1da177e4 LT |
1930 | if (unlikely((long)sum < 0)) |
1931 | sum = 0; | |
f711f609 | 1932 | |
1da177e4 | 1933 | return sum; |
f711f609 | 1934 | } |
f711f609 | 1935 | |
1da177e4 | 1936 | unsigned long long nr_context_switches(void) |
46cb4b7c | 1937 | { |
cc94abfc SR |
1938 | int i; |
1939 | unsigned long long sum = 0; | |
46cb4b7c | 1940 | |
0a945022 | 1941 | for_each_possible_cpu(i) |
1da177e4 | 1942 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 1943 | |
1da177e4 LT |
1944 | return sum; |
1945 | } | |
483b4ee6 | 1946 | |
1da177e4 LT |
1947 | unsigned long nr_iowait(void) |
1948 | { | |
1949 | unsigned long i, sum = 0; | |
483b4ee6 | 1950 | |
0a945022 | 1951 | for_each_possible_cpu(i) |
1da177e4 | 1952 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 1953 | |
1da177e4 LT |
1954 | return sum; |
1955 | } | |
483b4ee6 | 1956 | |
8c215bd3 | 1957 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 1958 | { |
8c215bd3 | 1959 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
1960 | return atomic_read(&this->nr_iowait); |
1961 | } | |
46cb4b7c | 1962 | |
69d25870 AV |
1963 | unsigned long this_cpu_load(void) |
1964 | { | |
1965 | struct rq *this = this_rq(); | |
1966 | return this->cpu_load[0]; | |
1967 | } | |
e790fb0b | 1968 | |
46cb4b7c | 1969 | |
5167e8d5 PZ |
1970 | /* |
1971 | * Global load-average calculations | |
1972 | * | |
1973 | * We take a distributed and async approach to calculating the global load-avg | |
1974 | * in order to minimize overhead. | |
1975 | * | |
1976 | * The global load average is an exponentially decaying average of nr_running + | |
1977 | * nr_uninterruptible. | |
1978 | * | |
1979 | * Once every LOAD_FREQ: | |
1980 | * | |
1981 | * nr_active = 0; | |
1982 | * for_each_possible_cpu(cpu) | |
1983 | * nr_active += cpu_of(cpu)->nr_running + cpu_of(cpu)->nr_uninterruptible; | |
1984 | * | |
1985 | * avenrun[n] = avenrun[0] * exp_n + nr_active * (1 - exp_n) | |
1986 | * | |
1987 | * Due to a number of reasons the above turns in the mess below: | |
1988 | * | |
1989 | * - for_each_possible_cpu() is prohibitively expensive on machines with | |
1990 | * serious number of cpus, therefore we need to take a distributed approach | |
1991 | * to calculating nr_active. | |
1992 | * | |
1993 | * \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0 | |
1994 | * = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) } | |
1995 | * | |
1996 | * So assuming nr_active := 0 when we start out -- true per definition, we | |
1997 | * can simply take per-cpu deltas and fold those into a global accumulate | |
1998 | * to obtain the same result. See calc_load_fold_active(). | |
1999 | * | |
2000 | * Furthermore, in order to avoid synchronizing all per-cpu delta folding | |
2001 | * across the machine, we assume 10 ticks is sufficient time for every | |
2002 | * cpu to have completed this task. | |
2003 | * | |
2004 | * This places an upper-bound on the IRQ-off latency of the machine. Then | |
2005 | * again, being late doesn't loose the delta, just wrecks the sample. | |
2006 | * | |
2007 | * - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because | |
2008 | * this would add another cross-cpu cacheline miss and atomic operation | |
2009 | * to the wakeup path. Instead we increment on whatever cpu the task ran | |
2010 | * when it went into uninterruptible state and decrement on whatever cpu | |
2011 | * did the wakeup. This means that only the sum of nr_uninterruptible over | |
2012 | * all cpus yields the correct result. | |
2013 | * | |
2014 | * This covers the NO_HZ=n code, for extra head-aches, see the comment below. | |
2015 | */ | |
2016 | ||
dce48a84 TG |
2017 | /* Variables and functions for calc_load */ |
2018 | static atomic_long_t calc_load_tasks; | |
2019 | static unsigned long calc_load_update; | |
2020 | unsigned long avenrun[3]; | |
5167e8d5 PZ |
2021 | EXPORT_SYMBOL(avenrun); /* should be removed */ |
2022 | ||
2023 | /** | |
2024 | * get_avenrun - get the load average array | |
2025 | * @loads: pointer to dest load array | |
2026 | * @offset: offset to add | |
2027 | * @shift: shift count to shift the result left | |
2028 | * | |
2029 | * These values are estimates at best, so no need for locking. | |
2030 | */ | |
2031 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
2032 | { | |
2033 | loads[0] = (avenrun[0] + offset) << shift; | |
2034 | loads[1] = (avenrun[1] + offset) << shift; | |
2035 | loads[2] = (avenrun[2] + offset) << shift; | |
2036 | } | |
46cb4b7c | 2037 | |
74f5187a PZ |
2038 | static long calc_load_fold_active(struct rq *this_rq) |
2039 | { | |
2040 | long nr_active, delta = 0; | |
2041 | ||
2042 | nr_active = this_rq->nr_running; | |
2043 | nr_active += (long) this_rq->nr_uninterruptible; | |
2044 | ||
2045 | if (nr_active != this_rq->calc_load_active) { | |
2046 | delta = nr_active - this_rq->calc_load_active; | |
2047 | this_rq->calc_load_active = nr_active; | |
2048 | } | |
2049 | ||
2050 | return delta; | |
2051 | } | |
2052 | ||
5167e8d5 PZ |
2053 | /* |
2054 | * a1 = a0 * e + a * (1 - e) | |
2055 | */ | |
0f004f5a PZ |
2056 | static unsigned long |
2057 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
2058 | { | |
2059 | load *= exp; | |
2060 | load += active * (FIXED_1 - exp); | |
2061 | load += 1UL << (FSHIFT - 1); | |
2062 | return load >> FSHIFT; | |
2063 | } | |
2064 | ||
74f5187a PZ |
2065 | #ifdef CONFIG_NO_HZ |
2066 | /* | |
5167e8d5 PZ |
2067 | * Handle NO_HZ for the global load-average. |
2068 | * | |
2069 | * Since the above described distributed algorithm to compute the global | |
2070 | * load-average relies on per-cpu sampling from the tick, it is affected by | |
2071 | * NO_HZ. | |
2072 | * | |
2073 | * The basic idea is to fold the nr_active delta into a global idle-delta upon | |
2074 | * entering NO_HZ state such that we can include this as an 'extra' cpu delta | |
2075 | * when we read the global state. | |
2076 | * | |
2077 | * Obviously reality has to ruin such a delightfully simple scheme: | |
2078 | * | |
2079 | * - When we go NO_HZ idle during the window, we can negate our sample | |
2080 | * contribution, causing under-accounting. | |
2081 | * | |
2082 | * We avoid this by keeping two idle-delta counters and flipping them | |
2083 | * when the window starts, thus separating old and new NO_HZ load. | |
2084 | * | |
2085 | * The only trick is the slight shift in index flip for read vs write. | |
2086 | * | |
2087 | * 0s 5s 10s 15s | |
2088 | * +10 +10 +10 +10 | |
2089 | * |-|-----------|-|-----------|-|-----------|-| | |
2090 | * r:0 0 1 1 0 0 1 1 0 | |
2091 | * w:0 1 1 0 0 1 1 0 0 | |
2092 | * | |
2093 | * This ensures we'll fold the old idle contribution in this window while | |
2094 | * accumlating the new one. | |
2095 | * | |
2096 | * - When we wake up from NO_HZ idle during the window, we push up our | |
2097 | * contribution, since we effectively move our sample point to a known | |
2098 | * busy state. | |
2099 | * | |
2100 | * This is solved by pushing the window forward, and thus skipping the | |
2101 | * sample, for this cpu (effectively using the idle-delta for this cpu which | |
2102 | * was in effect at the time the window opened). This also solves the issue | |
2103 | * of having to deal with a cpu having been in NOHZ idle for multiple | |
2104 | * LOAD_FREQ intervals. | |
74f5187a PZ |
2105 | * |
2106 | * When making the ILB scale, we should try to pull this in as well. | |
2107 | */ | |
5167e8d5 PZ |
2108 | static atomic_long_t calc_load_idle[2]; |
2109 | static int calc_load_idx; | |
74f5187a | 2110 | |
5167e8d5 | 2111 | static inline int calc_load_write_idx(void) |
74f5187a | 2112 | { |
5167e8d5 PZ |
2113 | int idx = calc_load_idx; |
2114 | ||
2115 | /* | |
2116 | * See calc_global_nohz(), if we observe the new index, we also | |
2117 | * need to observe the new update time. | |
2118 | */ | |
2119 | smp_rmb(); | |
2120 | ||
2121 | /* | |
2122 | * If the folding window started, make sure we start writing in the | |
2123 | * next idle-delta. | |
2124 | */ | |
2125 | if (!time_before(jiffies, calc_load_update)) | |
2126 | idx++; | |
2127 | ||
2128 | return idx & 1; | |
2129 | } | |
2130 | ||
2131 | static inline int calc_load_read_idx(void) | |
2132 | { | |
2133 | return calc_load_idx & 1; | |
2134 | } | |
2135 | ||
2136 | void calc_load_enter_idle(void) | |
2137 | { | |
2138 | struct rq *this_rq = this_rq(); | |
74f5187a PZ |
2139 | long delta; |
2140 | ||
5167e8d5 PZ |
2141 | /* |
2142 | * We're going into NOHZ mode, if there's any pending delta, fold it | |
2143 | * into the pending idle delta. | |
2144 | */ | |
74f5187a | 2145 | delta = calc_load_fold_active(this_rq); |
5167e8d5 PZ |
2146 | if (delta) { |
2147 | int idx = calc_load_write_idx(); | |
2148 | atomic_long_add(delta, &calc_load_idle[idx]); | |
2149 | } | |
74f5187a PZ |
2150 | } |
2151 | ||
5167e8d5 | 2152 | void calc_load_exit_idle(void) |
74f5187a | 2153 | { |
5167e8d5 PZ |
2154 | struct rq *this_rq = this_rq(); |
2155 | ||
2156 | /* | |
2157 | * If we're still before the sample window, we're done. | |
2158 | */ | |
2159 | if (time_before(jiffies, this_rq->calc_load_update)) | |
2160 | return; | |
74f5187a PZ |
2161 | |
2162 | /* | |
5167e8d5 PZ |
2163 | * We woke inside or after the sample window, this means we're already |
2164 | * accounted through the nohz accounting, so skip the entire deal and | |
2165 | * sync up for the next window. | |
74f5187a | 2166 | */ |
5167e8d5 PZ |
2167 | this_rq->calc_load_update = calc_load_update; |
2168 | if (time_before(jiffies, this_rq->calc_load_update + 10)) | |
2169 | this_rq->calc_load_update += LOAD_FREQ; | |
2170 | } | |
2171 | ||
2172 | static long calc_load_fold_idle(void) | |
2173 | { | |
2174 | int idx = calc_load_read_idx(); | |
2175 | long delta = 0; | |
2176 | ||
2177 | if (atomic_long_read(&calc_load_idle[idx])) | |
2178 | delta = atomic_long_xchg(&calc_load_idle[idx], 0); | |
74f5187a PZ |
2179 | |
2180 | return delta; | |
2181 | } | |
0f004f5a PZ |
2182 | |
2183 | /** | |
2184 | * fixed_power_int - compute: x^n, in O(log n) time | |
2185 | * | |
2186 | * @x: base of the power | |
2187 | * @frac_bits: fractional bits of @x | |
2188 | * @n: power to raise @x to. | |
2189 | * | |
2190 | * By exploiting the relation between the definition of the natural power | |
2191 | * function: x^n := x*x*...*x (x multiplied by itself for n times), and | |
2192 | * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i, | |
2193 | * (where: n_i \elem {0, 1}, the binary vector representing n), | |
2194 | * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is | |
2195 | * of course trivially computable in O(log_2 n), the length of our binary | |
2196 | * vector. | |
2197 | */ | |
2198 | static unsigned long | |
2199 | fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n) | |
2200 | { | |
2201 | unsigned long result = 1UL << frac_bits; | |
2202 | ||
2203 | if (n) for (;;) { | |
2204 | if (n & 1) { | |
2205 | result *= x; | |
2206 | result += 1UL << (frac_bits - 1); | |
2207 | result >>= frac_bits; | |
2208 | } | |
2209 | n >>= 1; | |
2210 | if (!n) | |
2211 | break; | |
2212 | x *= x; | |
2213 | x += 1UL << (frac_bits - 1); | |
2214 | x >>= frac_bits; | |
2215 | } | |
2216 | ||
2217 | return result; | |
2218 | } | |
2219 | ||
2220 | /* | |
2221 | * a1 = a0 * e + a * (1 - e) | |
2222 | * | |
2223 | * a2 = a1 * e + a * (1 - e) | |
2224 | * = (a0 * e + a * (1 - e)) * e + a * (1 - e) | |
2225 | * = a0 * e^2 + a * (1 - e) * (1 + e) | |
2226 | * | |
2227 | * a3 = a2 * e + a * (1 - e) | |
2228 | * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e) | |
2229 | * = a0 * e^3 + a * (1 - e) * (1 + e + e^2) | |
2230 | * | |
2231 | * ... | |
2232 | * | |
2233 | * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1] | |
2234 | * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e) | |
2235 | * = a0 * e^n + a * (1 - e^n) | |
2236 | * | |
2237 | * [1] application of the geometric series: | |
2238 | * | |
2239 | * n 1 - x^(n+1) | |
2240 | * S_n := \Sum x^i = ------------- | |
2241 | * i=0 1 - x | |
2242 | */ | |
2243 | static unsigned long | |
2244 | calc_load_n(unsigned long load, unsigned long exp, | |
2245 | unsigned long active, unsigned int n) | |
2246 | { | |
2247 | ||
2248 | return calc_load(load, fixed_power_int(exp, FSHIFT, n), active); | |
2249 | } | |
2250 | ||
2251 | /* | |
2252 | * NO_HZ can leave us missing all per-cpu ticks calling | |
2253 | * calc_load_account_active(), but since an idle CPU folds its delta into | |
2254 | * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold | |
2255 | * in the pending idle delta if our idle period crossed a load cycle boundary. | |
2256 | * | |
2257 | * Once we've updated the global active value, we need to apply the exponential | |
2258 | * weights adjusted to the number of cycles missed. | |
2259 | */ | |
c308b56b | 2260 | static void calc_global_nohz(void) |
0f004f5a PZ |
2261 | { |
2262 | long delta, active, n; | |
2263 | ||
5167e8d5 PZ |
2264 | if (!time_before(jiffies, calc_load_update + 10)) { |
2265 | /* | |
2266 | * Catch-up, fold however many we are behind still | |
2267 | */ | |
2268 | delta = jiffies - calc_load_update - 10; | |
2269 | n = 1 + (delta / LOAD_FREQ); | |
0f004f5a | 2270 | |
5167e8d5 PZ |
2271 | active = atomic_long_read(&calc_load_tasks); |
2272 | active = active > 0 ? active * FIXED_1 : 0; | |
0f004f5a | 2273 | |
5167e8d5 PZ |
2274 | avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n); |
2275 | avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n); | |
2276 | avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n); | |
0f004f5a | 2277 | |
5167e8d5 PZ |
2278 | calc_load_update += n * LOAD_FREQ; |
2279 | } | |
74f5187a | 2280 | |
5167e8d5 PZ |
2281 | /* |
2282 | * Flip the idle index... | |
2283 | * | |
2284 | * Make sure we first write the new time then flip the index, so that | |
2285 | * calc_load_write_idx() will see the new time when it reads the new | |
2286 | * index, this avoids a double flip messing things up. | |
2287 | */ | |
2288 | smp_wmb(); | |
2289 | calc_load_idx++; | |
74f5187a | 2290 | } |
5167e8d5 | 2291 | #else /* !CONFIG_NO_HZ */ |
0f004f5a | 2292 | |
5167e8d5 PZ |
2293 | static inline long calc_load_fold_idle(void) { return 0; } |
2294 | static inline void calc_global_nohz(void) { } | |
74f5187a | 2295 | |
5167e8d5 | 2296 | #endif /* CONFIG_NO_HZ */ |
46cb4b7c | 2297 | |
46cb4b7c | 2298 | /* |
dce48a84 TG |
2299 | * calc_load - update the avenrun load estimates 10 ticks after the |
2300 | * CPUs have updated calc_load_tasks. | |
7835b98b | 2301 | */ |
0f004f5a | 2302 | void calc_global_load(unsigned long ticks) |
7835b98b | 2303 | { |
5167e8d5 | 2304 | long active, delta; |
1da177e4 | 2305 | |
0f004f5a | 2306 | if (time_before(jiffies, calc_load_update + 10)) |
dce48a84 | 2307 | return; |
1da177e4 | 2308 | |
5167e8d5 PZ |
2309 | /* |
2310 | * Fold the 'old' idle-delta to include all NO_HZ cpus. | |
2311 | */ | |
2312 | delta = calc_load_fold_idle(); | |
2313 | if (delta) | |
2314 | atomic_long_add(delta, &calc_load_tasks); | |
2315 | ||
dce48a84 TG |
2316 | active = atomic_long_read(&calc_load_tasks); |
2317 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 2318 | |
dce48a84 TG |
2319 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
2320 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
2321 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 2322 | |
dce48a84 | 2323 | calc_load_update += LOAD_FREQ; |
c308b56b PZ |
2324 | |
2325 | /* | |
5167e8d5 | 2326 | * In case we idled for multiple LOAD_FREQ intervals, catch up in bulk. |
c308b56b PZ |
2327 | */ |
2328 | calc_global_nohz(); | |
dce48a84 | 2329 | } |
1da177e4 | 2330 | |
dce48a84 | 2331 | /* |
74f5187a PZ |
2332 | * Called from update_cpu_load() to periodically update this CPU's |
2333 | * active count. | |
dce48a84 TG |
2334 | */ |
2335 | static void calc_load_account_active(struct rq *this_rq) | |
2336 | { | |
74f5187a | 2337 | long delta; |
08c183f3 | 2338 | |
74f5187a PZ |
2339 | if (time_before(jiffies, this_rq->calc_load_update)) |
2340 | return; | |
783609c6 | 2341 | |
74f5187a | 2342 | delta = calc_load_fold_active(this_rq); |
74f5187a | 2343 | if (delta) |
dce48a84 | 2344 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
2345 | |
2346 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
2347 | } |
2348 | ||
5167e8d5 PZ |
2349 | /* |
2350 | * End of global load-average stuff | |
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 | */ |
556061b0 PZ |
2425 | static void __update_cpu_load(struct rq *this_rq, unsigned long this_load, |
2426 | unsigned long pending_updates) | |
46cb4b7c | 2427 | { |
dd41f596 | 2428 | int i, scale; |
46cb4b7c | 2429 | |
dd41f596 | 2430 | this_rq->nr_load_updates++; |
46cb4b7c | 2431 | |
dd41f596 | 2432 | /* Update our load: */ |
fdf3e95d VP |
2433 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
2434 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
dd41f596 | 2435 | unsigned long old_load, new_load; |
7d1e6a9b | 2436 | |
dd41f596 | 2437 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 2438 | |
dd41f596 | 2439 | old_load = this_rq->cpu_load[i]; |
fdf3e95d | 2440 | old_load = decay_load_missed(old_load, pending_updates - 1, i); |
dd41f596 | 2441 | new_load = this_load; |
a25707f3 IM |
2442 | /* |
2443 | * Round up the averaging division if load is increasing. This | |
2444 | * prevents us from getting stuck on 9 if the load is 10, for | |
2445 | * example. | |
2446 | */ | |
2447 | if (new_load > old_load) | |
fdf3e95d VP |
2448 | new_load += scale - 1; |
2449 | ||
2450 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | |
dd41f596 | 2451 | } |
da2b71ed SS |
2452 | |
2453 | sched_avg_update(this_rq); | |
fdf3e95d VP |
2454 | } |
2455 | ||
5aaa0b7a PZ |
2456 | #ifdef CONFIG_NO_HZ |
2457 | /* | |
2458 | * There is no sane way to deal with nohz on smp when using jiffies because the | |
2459 | * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading | |
2460 | * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}. | |
2461 | * | |
2462 | * Therefore we cannot use the delta approach from the regular tick since that | |
2463 | * would seriously skew the load calculation. However we'll make do for those | |
2464 | * updates happening while idle (nohz_idle_balance) or coming out of idle | |
2465 | * (tick_nohz_idle_exit). | |
2466 | * | |
2467 | * This means we might still be one tick off for nohz periods. | |
2468 | */ | |
2469 | ||
556061b0 PZ |
2470 | /* |
2471 | * Called from nohz_idle_balance() to update the load ratings before doing the | |
2472 | * idle balance. | |
2473 | */ | |
2474 | void update_idle_cpu_load(struct rq *this_rq) | |
2475 | { | |
5aaa0b7a | 2476 | unsigned long curr_jiffies = ACCESS_ONCE(jiffies); |
556061b0 PZ |
2477 | unsigned long load = this_rq->load.weight; |
2478 | unsigned long pending_updates; | |
2479 | ||
2480 | /* | |
5aaa0b7a | 2481 | * bail if there's load or we're actually up-to-date. |
556061b0 PZ |
2482 | */ |
2483 | if (load || curr_jiffies == this_rq->last_load_update_tick) | |
2484 | return; | |
2485 | ||
2486 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
2487 | this_rq->last_load_update_tick = curr_jiffies; | |
2488 | ||
2489 | __update_cpu_load(this_rq, load, pending_updates); | |
2490 | } | |
2491 | ||
5aaa0b7a PZ |
2492 | /* |
2493 | * Called from tick_nohz_idle_exit() -- try and fix up the ticks we missed. | |
2494 | */ | |
2495 | void update_cpu_load_nohz(void) | |
2496 | { | |
2497 | struct rq *this_rq = this_rq(); | |
2498 | unsigned long curr_jiffies = ACCESS_ONCE(jiffies); | |
2499 | unsigned long pending_updates; | |
2500 | ||
2501 | if (curr_jiffies == this_rq->last_load_update_tick) | |
2502 | return; | |
2503 | ||
2504 | raw_spin_lock(&this_rq->lock); | |
2505 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
2506 | if (pending_updates) { | |
2507 | this_rq->last_load_update_tick = curr_jiffies; | |
2508 | /* | |
2509 | * We were idle, this means load 0, the current load might be | |
2510 | * !0 due to remote wakeups and the sort. | |
2511 | */ | |
2512 | __update_cpu_load(this_rq, 0, pending_updates); | |
2513 | } | |
2514 | raw_spin_unlock(&this_rq->lock); | |
2515 | } | |
2516 | #endif /* CONFIG_NO_HZ */ | |
2517 | ||
556061b0 PZ |
2518 | /* |
2519 | * Called from scheduler_tick() | |
2520 | */ | |
fdf3e95d VP |
2521 | static void update_cpu_load_active(struct rq *this_rq) |
2522 | { | |
556061b0 | 2523 | /* |
5aaa0b7a | 2524 | * See the mess around update_idle_cpu_load() / update_cpu_load_nohz(). |
556061b0 PZ |
2525 | */ |
2526 | this_rq->last_load_update_tick = jiffies; | |
2527 | __update_cpu_load(this_rq, this_rq->load.weight, 1); | |
46cb4b7c | 2528 | |
74f5187a | 2529 | calc_load_account_active(this_rq); |
46cb4b7c SS |
2530 | } |
2531 | ||
dd41f596 | 2532 | #ifdef CONFIG_SMP |
8a0be9ef | 2533 | |
46cb4b7c | 2534 | /* |
38022906 PZ |
2535 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2536 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 2537 | */ |
38022906 | 2538 | void sched_exec(void) |
46cb4b7c | 2539 | { |
38022906 | 2540 | struct task_struct *p = current; |
1da177e4 | 2541 | unsigned long flags; |
0017d735 | 2542 | int dest_cpu; |
46cb4b7c | 2543 | |
8f42ced9 | 2544 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
7608dec2 | 2545 | dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); |
0017d735 PZ |
2546 | if (dest_cpu == smp_processor_id()) |
2547 | goto unlock; | |
38022906 | 2548 | |
8f42ced9 | 2549 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 2550 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 2551 | |
8f42ced9 PZ |
2552 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2553 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
2554 | return; |
2555 | } | |
0017d735 | 2556 | unlock: |
8f42ced9 | 2557 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 2558 | } |
dd41f596 | 2559 | |
1da177e4 LT |
2560 | #endif |
2561 | ||
1da177e4 | 2562 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3292beb3 | 2563 | DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); |
1da177e4 LT |
2564 | |
2565 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3292beb3 | 2566 | EXPORT_PER_CPU_SYMBOL(kernel_cpustat); |
1da177e4 LT |
2567 | |
2568 | /* | |
c5f8d995 | 2569 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 2570 | * @p in case that task is currently running. |
c5f8d995 HS |
2571 | * |
2572 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 2573 | */ |
c5f8d995 HS |
2574 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
2575 | { | |
2576 | u64 ns = 0; | |
2577 | ||
2578 | if (task_current(rq, p)) { | |
2579 | update_rq_clock(rq); | |
305e6835 | 2580 | ns = rq->clock_task - p->se.exec_start; |
c5f8d995 HS |
2581 | if ((s64)ns < 0) |
2582 | ns = 0; | |
2583 | } | |
2584 | ||
2585 | return ns; | |
2586 | } | |
2587 | ||
bb34d92f | 2588 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 2589 | { |
1da177e4 | 2590 | unsigned long flags; |
41b86e9c | 2591 | struct rq *rq; |
bb34d92f | 2592 | u64 ns = 0; |
48f24c4d | 2593 | |
41b86e9c | 2594 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 2595 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 2596 | task_rq_unlock(rq, p, &flags); |
1508487e | 2597 | |
c5f8d995 HS |
2598 | return ns; |
2599 | } | |
f06febc9 | 2600 | |
c5f8d995 HS |
2601 | /* |
2602 | * Return accounted runtime for the task. | |
2603 | * In case the task is currently running, return the runtime plus current's | |
2604 | * pending runtime that have not been accounted yet. | |
2605 | */ | |
2606 | unsigned long long task_sched_runtime(struct task_struct *p) | |
2607 | { | |
2608 | unsigned long flags; | |
2609 | struct rq *rq; | |
2610 | u64 ns = 0; | |
2611 | ||
2612 | rq = task_rq_lock(p, &flags); | |
2613 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 2614 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
2615 | |
2616 | return ns; | |
2617 | } | |
48f24c4d | 2618 | |
7835b98b CL |
2619 | /* |
2620 | * This function gets called by the timer code, with HZ frequency. | |
2621 | * We call it with interrupts disabled. | |
7835b98b CL |
2622 | */ |
2623 | void scheduler_tick(void) | |
2624 | { | |
7835b98b CL |
2625 | int cpu = smp_processor_id(); |
2626 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 2627 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
2628 | |
2629 | sched_clock_tick(); | |
dd41f596 | 2630 | |
05fa785c | 2631 | raw_spin_lock(&rq->lock); |
3e51f33f | 2632 | update_rq_clock(rq); |
fdf3e95d | 2633 | update_cpu_load_active(rq); |
fa85ae24 | 2634 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 2635 | raw_spin_unlock(&rq->lock); |
7835b98b | 2636 | |
e9d2b064 | 2637 | perf_event_task_tick(); |
e220d2dc | 2638 | |
e418e1c2 | 2639 | #ifdef CONFIG_SMP |
6eb57e0d | 2640 | rq->idle_balance = idle_cpu(cpu); |
dd41f596 | 2641 | trigger_load_balance(rq, cpu); |
e418e1c2 | 2642 | #endif |
1da177e4 LT |
2643 | } |
2644 | ||
132380a0 | 2645 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
2646 | { |
2647 | if (in_lock_functions(addr)) { | |
2648 | addr = CALLER_ADDR2; | |
2649 | if (in_lock_functions(addr)) | |
2650 | addr = CALLER_ADDR3; | |
2651 | } | |
2652 | return addr; | |
2653 | } | |
1da177e4 | 2654 | |
7e49fcce SR |
2655 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
2656 | defined(CONFIG_PREEMPT_TRACER)) | |
2657 | ||
43627582 | 2658 | void __kprobes add_preempt_count(int val) |
1da177e4 | 2659 | { |
6cd8a4bb | 2660 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2661 | /* |
2662 | * Underflow? | |
2663 | */ | |
9a11b49a IM |
2664 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
2665 | return; | |
6cd8a4bb | 2666 | #endif |
1da177e4 | 2667 | preempt_count() += val; |
6cd8a4bb | 2668 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2669 | /* |
2670 | * Spinlock count overflowing soon? | |
2671 | */ | |
33859f7f MOS |
2672 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
2673 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
2674 | #endif |
2675 | if (preempt_count() == val) | |
2676 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
2677 | } |
2678 | EXPORT_SYMBOL(add_preempt_count); | |
2679 | ||
43627582 | 2680 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 2681 | { |
6cd8a4bb | 2682 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2683 | /* |
2684 | * Underflow? | |
2685 | */ | |
01e3eb82 | 2686 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 2687 | return; |
1da177e4 LT |
2688 | /* |
2689 | * Is the spinlock portion underflowing? | |
2690 | */ | |
9a11b49a IM |
2691 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
2692 | !(preempt_count() & PREEMPT_MASK))) | |
2693 | return; | |
6cd8a4bb | 2694 | #endif |
9a11b49a | 2695 | |
6cd8a4bb SR |
2696 | if (preempt_count() == val) |
2697 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
2698 | preempt_count() -= val; |
2699 | } | |
2700 | EXPORT_SYMBOL(sub_preempt_count); | |
2701 | ||
2702 | #endif | |
2703 | ||
2704 | /* | |
dd41f596 | 2705 | * Print scheduling while atomic bug: |
1da177e4 | 2706 | */ |
dd41f596 | 2707 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 2708 | { |
664dfa65 DJ |
2709 | if (oops_in_progress) |
2710 | return; | |
2711 | ||
3df0fc5b PZ |
2712 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
2713 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 2714 | |
dd41f596 | 2715 | debug_show_held_locks(prev); |
e21f5b15 | 2716 | print_modules(); |
dd41f596 IM |
2717 | if (irqs_disabled()) |
2718 | print_irqtrace_events(prev); | |
6135fc1e | 2719 | dump_stack(); |
1c2927f1 | 2720 | add_taint(TAINT_WARN); |
dd41f596 | 2721 | } |
1da177e4 | 2722 | |
dd41f596 IM |
2723 | /* |
2724 | * Various schedule()-time debugging checks and statistics: | |
2725 | */ | |
2726 | static inline void schedule_debug(struct task_struct *prev) | |
2727 | { | |
1da177e4 | 2728 | /* |
41a2d6cf | 2729 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
2730 | * schedule() atomically, we ignore that path for now. |
2731 | * Otherwise, whine if we are scheduling when we should not be. | |
2732 | */ | |
3f33a7ce | 2733 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 | 2734 | __schedule_bug(prev); |
b3fbab05 | 2735 | rcu_sleep_check(); |
dd41f596 | 2736 | |
1da177e4 LT |
2737 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
2738 | ||
2d72376b | 2739 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
2740 | } |
2741 | ||
6cecd084 | 2742 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 2743 | { |
61eadef6 | 2744 | if (prev->on_rq || rq->skip_clock_update < 0) |
a64692a3 | 2745 | update_rq_clock(rq); |
6cecd084 | 2746 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
2747 | } |
2748 | ||
dd41f596 IM |
2749 | /* |
2750 | * Pick up the highest-prio task: | |
2751 | */ | |
2752 | static inline struct task_struct * | |
b67802ea | 2753 | pick_next_task(struct rq *rq) |
dd41f596 | 2754 | { |
5522d5d5 | 2755 | const struct sched_class *class; |
dd41f596 | 2756 | struct task_struct *p; |
1da177e4 LT |
2757 | |
2758 | /* | |
dd41f596 IM |
2759 | * Optimization: we know that if all tasks are in |
2760 | * the fair class we can call that function directly: | |
1da177e4 | 2761 | */ |
953bfcd1 | 2762 | if (likely(rq->nr_running == rq->cfs.h_nr_running)) { |
fb8d4724 | 2763 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
2764 | if (likely(p)) |
2765 | return p; | |
1da177e4 LT |
2766 | } |
2767 | ||
34f971f6 | 2768 | for_each_class(class) { |
fb8d4724 | 2769 | p = class->pick_next_task(rq); |
dd41f596 IM |
2770 | if (p) |
2771 | return p; | |
dd41f596 | 2772 | } |
34f971f6 PZ |
2773 | |
2774 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 2775 | } |
1da177e4 | 2776 | |
dd41f596 | 2777 | /* |
c259e01a | 2778 | * __schedule() is the main scheduler function. |
edde96ea PE |
2779 | * |
2780 | * The main means of driving the scheduler and thus entering this function are: | |
2781 | * | |
2782 | * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. | |
2783 | * | |
2784 | * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return | |
2785 | * paths. For example, see arch/x86/entry_64.S. | |
2786 | * | |
2787 | * To drive preemption between tasks, the scheduler sets the flag in timer | |
2788 | * interrupt handler scheduler_tick(). | |
2789 | * | |
2790 | * 3. Wakeups don't really cause entry into schedule(). They add a | |
2791 | * task to the run-queue and that's it. | |
2792 | * | |
2793 | * Now, if the new task added to the run-queue preempts the current | |
2794 | * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets | |
2795 | * called on the nearest possible occasion: | |
2796 | * | |
2797 | * - If the kernel is preemptible (CONFIG_PREEMPT=y): | |
2798 | * | |
2799 | * - in syscall or exception context, at the next outmost | |
2800 | * preempt_enable(). (this might be as soon as the wake_up()'s | |
2801 | * spin_unlock()!) | |
2802 | * | |
2803 | * - in IRQ context, return from interrupt-handler to | |
2804 | * preemptible context | |
2805 | * | |
2806 | * - If the kernel is not preemptible (CONFIG_PREEMPT is not set) | |
2807 | * then at the next: | |
2808 | * | |
2809 | * - cond_resched() call | |
2810 | * - explicit schedule() call | |
2811 | * - return from syscall or exception to user-space | |
2812 | * - return from interrupt-handler to user-space | |
dd41f596 | 2813 | */ |
c259e01a | 2814 | static void __sched __schedule(void) |
dd41f596 IM |
2815 | { |
2816 | struct task_struct *prev, *next; | |
67ca7bde | 2817 | unsigned long *switch_count; |
dd41f596 | 2818 | struct rq *rq; |
31656519 | 2819 | int cpu; |
dd41f596 | 2820 | |
ff743345 PZ |
2821 | need_resched: |
2822 | preempt_disable(); | |
dd41f596 IM |
2823 | cpu = smp_processor_id(); |
2824 | rq = cpu_rq(cpu); | |
25502a6c | 2825 | rcu_note_context_switch(cpu); |
dd41f596 | 2826 | prev = rq->curr; |
dd41f596 | 2827 | |
dd41f596 | 2828 | schedule_debug(prev); |
1da177e4 | 2829 | |
31656519 | 2830 | if (sched_feat(HRTICK)) |
f333fdc9 | 2831 | hrtick_clear(rq); |
8f4d37ec | 2832 | |
05fa785c | 2833 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 2834 | |
246d86b5 | 2835 | switch_count = &prev->nivcsw; |
1da177e4 | 2836 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 2837 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 2838 | prev->state = TASK_RUNNING; |
21aa9af0 | 2839 | } else { |
2acca55e PZ |
2840 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
2841 | prev->on_rq = 0; | |
2842 | ||
21aa9af0 | 2843 | /* |
2acca55e PZ |
2844 | * If a worker went to sleep, notify and ask workqueue |
2845 | * whether it wants to wake up a task to maintain | |
2846 | * concurrency. | |
21aa9af0 TH |
2847 | */ |
2848 | if (prev->flags & PF_WQ_WORKER) { | |
2849 | struct task_struct *to_wakeup; | |
2850 | ||
2851 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
2852 | if (to_wakeup) | |
2853 | try_to_wake_up_local(to_wakeup); | |
2854 | } | |
21aa9af0 | 2855 | } |
dd41f596 | 2856 | switch_count = &prev->nvcsw; |
1da177e4 LT |
2857 | } |
2858 | ||
3f029d3c | 2859 | pre_schedule(rq, prev); |
f65eda4f | 2860 | |
dd41f596 | 2861 | if (unlikely(!rq->nr_running)) |
1da177e4 | 2862 | idle_balance(cpu, rq); |
1da177e4 | 2863 | |
df1c99d4 | 2864 | put_prev_task(rq, prev); |
b67802ea | 2865 | next = pick_next_task(rq); |
f26f9aff MG |
2866 | clear_tsk_need_resched(prev); |
2867 | rq->skip_clock_update = 0; | |
1da177e4 | 2868 | |
1da177e4 | 2869 | if (likely(prev != next)) { |
1da177e4 LT |
2870 | rq->nr_switches++; |
2871 | rq->curr = next; | |
2872 | ++*switch_count; | |
2873 | ||
dd41f596 | 2874 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 2875 | /* |
246d86b5 ON |
2876 | * The context switch have flipped the stack from under us |
2877 | * and restored the local variables which were saved when | |
2878 | * this task called schedule() in the past. prev == current | |
2879 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
2880 | */ |
2881 | cpu = smp_processor_id(); | |
2882 | rq = cpu_rq(cpu); | |
1da177e4 | 2883 | } else |
05fa785c | 2884 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 2885 | |
3f029d3c | 2886 | post_schedule(rq); |
1da177e4 | 2887 | |
ba74c144 | 2888 | sched_preempt_enable_no_resched(); |
ff743345 | 2889 | if (need_resched()) |
1da177e4 LT |
2890 | goto need_resched; |
2891 | } | |
c259e01a | 2892 | |
9c40cef2 TG |
2893 | static inline void sched_submit_work(struct task_struct *tsk) |
2894 | { | |
3c7d5184 | 2895 | if (!tsk->state || tsk_is_pi_blocked(tsk)) |
9c40cef2 TG |
2896 | return; |
2897 | /* | |
2898 | * If we are going to sleep and we have plugged IO queued, | |
2899 | * make sure to submit it to avoid deadlocks. | |
2900 | */ | |
2901 | if (blk_needs_flush_plug(tsk)) | |
2902 | blk_schedule_flush_plug(tsk); | |
2903 | } | |
2904 | ||
6ebbe7a0 | 2905 | asmlinkage void __sched schedule(void) |
c259e01a | 2906 | { |
9c40cef2 TG |
2907 | struct task_struct *tsk = current; |
2908 | ||
2909 | sched_submit_work(tsk); | |
c259e01a TG |
2910 | __schedule(); |
2911 | } | |
1da177e4 LT |
2912 | EXPORT_SYMBOL(schedule); |
2913 | ||
20ab65e3 FW |
2914 | #ifdef CONFIG_RCU_USER_QS |
2915 | asmlinkage void __sched schedule_user(void) | |
2916 | { | |
2917 | /* | |
2918 | * If we come here after a random call to set_need_resched(), | |
2919 | * or we have been woken up remotely but the IPI has not yet arrived, | |
2920 | * we haven't yet exited the RCU idle mode. Do it here manually until | |
2921 | * we find a better solution. | |
2922 | */ | |
2923 | rcu_user_exit(); | |
2924 | schedule(); | |
2925 | rcu_user_enter(); | |
2926 | } | |
2927 | #endif | |
2928 | ||
c5491ea7 TG |
2929 | /** |
2930 | * schedule_preempt_disabled - called with preemption disabled | |
2931 | * | |
2932 | * Returns with preemption disabled. Note: preempt_count must be 1 | |
2933 | */ | |
2934 | void __sched schedule_preempt_disabled(void) | |
2935 | { | |
ba74c144 | 2936 | sched_preempt_enable_no_resched(); |
c5491ea7 TG |
2937 | schedule(); |
2938 | preempt_disable(); | |
2939 | } | |
2940 | ||
c08f7829 | 2941 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d | 2942 | |
c6eb3dda PZ |
2943 | static inline bool owner_running(struct mutex *lock, struct task_struct *owner) |
2944 | { | |
c6eb3dda | 2945 | if (lock->owner != owner) |
307bf980 | 2946 | return false; |
0d66bf6d PZ |
2947 | |
2948 | /* | |
c6eb3dda PZ |
2949 | * Ensure we emit the owner->on_cpu, dereference _after_ checking |
2950 | * lock->owner still matches owner, if that fails, owner might | |
2951 | * point to free()d memory, if it still matches, the rcu_read_lock() | |
2952 | * ensures the memory stays valid. | |
0d66bf6d | 2953 | */ |
c6eb3dda | 2954 | barrier(); |
0d66bf6d | 2955 | |
307bf980 | 2956 | return owner->on_cpu; |
c6eb3dda | 2957 | } |
0d66bf6d | 2958 | |
c6eb3dda PZ |
2959 | /* |
2960 | * Look out! "owner" is an entirely speculative pointer | |
2961 | * access and not reliable. | |
2962 | */ | |
2963 | int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) | |
2964 | { | |
2965 | if (!sched_feat(OWNER_SPIN)) | |
2966 | return 0; | |
0d66bf6d | 2967 | |
307bf980 | 2968 | rcu_read_lock(); |
c6eb3dda PZ |
2969 | while (owner_running(lock, owner)) { |
2970 | if (need_resched()) | |
307bf980 | 2971 | break; |
0d66bf6d | 2972 | |
335d7afb | 2973 | arch_mutex_cpu_relax(); |
0d66bf6d | 2974 | } |
307bf980 | 2975 | rcu_read_unlock(); |
4b402210 | 2976 | |
c6eb3dda | 2977 | /* |
307bf980 TG |
2978 | * We break out the loop above on need_resched() and when the |
2979 | * owner changed, which is a sign for heavy contention. Return | |
2980 | * success only when lock->owner is NULL. | |
c6eb3dda | 2981 | */ |
307bf980 | 2982 | return lock->owner == NULL; |
0d66bf6d PZ |
2983 | } |
2984 | #endif | |
2985 | ||
1da177e4 LT |
2986 | #ifdef CONFIG_PREEMPT |
2987 | /* | |
2ed6e34f | 2988 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 2989 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
2990 | * occur there and call schedule directly. |
2991 | */ | |
d1f74e20 | 2992 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
2993 | { |
2994 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 2995 | |
1da177e4 LT |
2996 | /* |
2997 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 2998 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 2999 | */ |
beed33a8 | 3000 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
3001 | return; |
3002 | ||
3a5c359a | 3003 | do { |
d1f74e20 | 3004 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
c259e01a | 3005 | __schedule(); |
d1f74e20 | 3006 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 3007 | |
3a5c359a AK |
3008 | /* |
3009 | * Check again in case we missed a preemption opportunity | |
3010 | * between schedule and now. | |
3011 | */ | |
3012 | barrier(); | |
5ed0cec0 | 3013 | } while (need_resched()); |
1da177e4 | 3014 | } |
1da177e4 LT |
3015 | EXPORT_SYMBOL(preempt_schedule); |
3016 | ||
3017 | /* | |
2ed6e34f | 3018 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
3019 | * off of irq context. |
3020 | * Note, that this is called and return with irqs disabled. This will | |
3021 | * protect us against recursive calling from irq. | |
3022 | */ | |
3023 | asmlinkage void __sched preempt_schedule_irq(void) | |
3024 | { | |
3025 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3026 | |
2ed6e34f | 3027 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
3028 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
3029 | ||
90a340ed | 3030 | rcu_user_exit(); |
3a5c359a AK |
3031 | do { |
3032 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 3033 | local_irq_enable(); |
c259e01a | 3034 | __schedule(); |
3a5c359a | 3035 | local_irq_disable(); |
3a5c359a | 3036 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3037 | |
3a5c359a AK |
3038 | /* |
3039 | * Check again in case we missed a preemption opportunity | |
3040 | * between schedule and now. | |
3041 | */ | |
3042 | barrier(); | |
5ed0cec0 | 3043 | } while (need_resched()); |
1da177e4 LT |
3044 | } |
3045 | ||
3046 | #endif /* CONFIG_PREEMPT */ | |
3047 | ||
63859d4f | 3048 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3049 | void *key) |
1da177e4 | 3050 | { |
63859d4f | 3051 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3052 | } |
1da177e4 LT |
3053 | EXPORT_SYMBOL(default_wake_function); |
3054 | ||
3055 | /* | |
41a2d6cf IM |
3056 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
3057 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
3058 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
3059 | * | |
3060 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 3061 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
3062 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
3063 | */ | |
78ddb08f | 3064 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 3065 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 3066 | { |
2e45874c | 3067 | wait_queue_t *curr, *next; |
1da177e4 | 3068 | |
2e45874c | 3069 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
3070 | unsigned flags = curr->flags; |
3071 | ||
63859d4f | 3072 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 3073 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
3074 | break; |
3075 | } | |
3076 | } | |
3077 | ||
3078 | /** | |
3079 | * __wake_up - wake up threads blocked on a waitqueue. | |
3080 | * @q: the waitqueue | |
3081 | * @mode: which threads | |
3082 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 3083 | * @key: is directly passed to the wakeup function |
50fa610a DH |
3084 | * |
3085 | * It may be assumed that this function implies a write memory barrier before | |
3086 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3087 | */ |
7ad5b3a5 | 3088 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 3089 | int nr_exclusive, void *key) |
1da177e4 LT |
3090 | { |
3091 | unsigned long flags; | |
3092 | ||
3093 | spin_lock_irqsave(&q->lock, flags); | |
3094 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
3095 | spin_unlock_irqrestore(&q->lock, flags); | |
3096 | } | |
1da177e4 LT |
3097 | EXPORT_SYMBOL(__wake_up); |
3098 | ||
3099 | /* | |
3100 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
3101 | */ | |
63b20011 | 3102 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr) |
1da177e4 | 3103 | { |
63b20011 | 3104 | __wake_up_common(q, mode, nr, 0, NULL); |
1da177e4 | 3105 | } |
22c43c81 | 3106 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 3107 | |
4ede816a DL |
3108 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
3109 | { | |
3110 | __wake_up_common(q, mode, 1, 0, key); | |
3111 | } | |
bf294b41 | 3112 | EXPORT_SYMBOL_GPL(__wake_up_locked_key); |
4ede816a | 3113 | |
1da177e4 | 3114 | /** |
4ede816a | 3115 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
3116 | * @q: the waitqueue |
3117 | * @mode: which threads | |
3118 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 3119 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
3120 | * |
3121 | * The sync wakeup differs that the waker knows that it will schedule | |
3122 | * away soon, so while the target thread will be woken up, it will not | |
3123 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
3124 | * with each other. This can prevent needless bouncing between CPUs. | |
3125 | * | |
3126 | * On UP it can prevent extra preemption. | |
50fa610a DH |
3127 | * |
3128 | * It may be assumed that this function implies a write memory barrier before | |
3129 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3130 | */ |
4ede816a DL |
3131 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
3132 | int nr_exclusive, void *key) | |
1da177e4 LT |
3133 | { |
3134 | unsigned long flags; | |
7d478721 | 3135 | int wake_flags = WF_SYNC; |
1da177e4 LT |
3136 | |
3137 | if (unlikely(!q)) | |
3138 | return; | |
3139 | ||
3140 | if (unlikely(!nr_exclusive)) | |
7d478721 | 3141 | wake_flags = 0; |
1da177e4 LT |
3142 | |
3143 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 3144 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
3145 | spin_unlock_irqrestore(&q->lock, flags); |
3146 | } | |
4ede816a DL |
3147 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
3148 | ||
3149 | /* | |
3150 | * __wake_up_sync - see __wake_up_sync_key() | |
3151 | */ | |
3152 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
3153 | { | |
3154 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
3155 | } | |
1da177e4 LT |
3156 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
3157 | ||
65eb3dc6 KD |
3158 | /** |
3159 | * complete: - signals a single thread waiting on this completion | |
3160 | * @x: holds the state of this particular completion | |
3161 | * | |
3162 | * This will wake up a single thread waiting on this completion. Threads will be | |
3163 | * awakened in the same order in which they were queued. | |
3164 | * | |
3165 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
3166 | * |
3167 | * It may be assumed that this function implies a write memory barrier before | |
3168 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3169 | */ |
b15136e9 | 3170 | void complete(struct completion *x) |
1da177e4 LT |
3171 | { |
3172 | unsigned long flags; | |
3173 | ||
3174 | spin_lock_irqsave(&x->wait.lock, flags); | |
3175 | x->done++; | |
d9514f6c | 3176 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
3177 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3178 | } | |
3179 | EXPORT_SYMBOL(complete); | |
3180 | ||
65eb3dc6 KD |
3181 | /** |
3182 | * complete_all: - signals all threads waiting on this completion | |
3183 | * @x: holds the state of this particular completion | |
3184 | * | |
3185 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
3186 | * |
3187 | * It may be assumed that this function implies a write memory barrier before | |
3188 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 3189 | */ |
b15136e9 | 3190 | void complete_all(struct completion *x) |
1da177e4 LT |
3191 | { |
3192 | unsigned long flags; | |
3193 | ||
3194 | spin_lock_irqsave(&x->wait.lock, flags); | |
3195 | x->done += UINT_MAX/2; | |
d9514f6c | 3196 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
3197 | spin_unlock_irqrestore(&x->wait.lock, flags); |
3198 | } | |
3199 | EXPORT_SYMBOL(complete_all); | |
3200 | ||
8cbbe86d AK |
3201 | static inline long __sched |
3202 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3203 | { |
1da177e4 LT |
3204 | if (!x->done) { |
3205 | DECLARE_WAITQUEUE(wait, current); | |
3206 | ||
a93d2f17 | 3207 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 3208 | do { |
94d3d824 | 3209 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
3210 | timeout = -ERESTARTSYS; |
3211 | break; | |
8cbbe86d AK |
3212 | } |
3213 | __set_current_state(state); | |
1da177e4 LT |
3214 | spin_unlock_irq(&x->wait.lock); |
3215 | timeout = schedule_timeout(timeout); | |
3216 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 3217 | } while (!x->done && timeout); |
1da177e4 | 3218 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
3219 | if (!x->done) |
3220 | return timeout; | |
1da177e4 LT |
3221 | } |
3222 | x->done--; | |
ea71a546 | 3223 | return timeout ?: 1; |
1da177e4 | 3224 | } |
1da177e4 | 3225 | |
8cbbe86d AK |
3226 | static long __sched |
3227 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 3228 | { |
1da177e4 LT |
3229 | might_sleep(); |
3230 | ||
3231 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 3232 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 3233 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
3234 | return timeout; |
3235 | } | |
1da177e4 | 3236 | |
65eb3dc6 KD |
3237 | /** |
3238 | * wait_for_completion: - waits for completion of a task | |
3239 | * @x: holds the state of this particular completion | |
3240 | * | |
3241 | * This waits to be signaled for completion of a specific task. It is NOT | |
3242 | * interruptible and there is no timeout. | |
3243 | * | |
3244 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
3245 | * and interrupt capability. Also see complete(). | |
3246 | */ | |
b15136e9 | 3247 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
3248 | { |
3249 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 3250 | } |
8cbbe86d | 3251 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 3252 | |
65eb3dc6 KD |
3253 | /** |
3254 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
3255 | * @x: holds the state of this particular completion | |
3256 | * @timeout: timeout value in jiffies | |
3257 | * | |
3258 | * This waits for either a completion of a specific task to be signaled or for a | |
3259 | * specified timeout to expire. The timeout is in jiffies. It is not | |
3260 | * interruptible. | |
c6dc7f05 BF |
3261 | * |
3262 | * The return value is 0 if timed out, and positive (at least 1, or number of | |
3263 | * jiffies left till timeout) if completed. | |
65eb3dc6 | 3264 | */ |
b15136e9 | 3265 | unsigned long __sched |
8cbbe86d | 3266 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 3267 | { |
8cbbe86d | 3268 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 3269 | } |
8cbbe86d | 3270 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 3271 | |
65eb3dc6 KD |
3272 | /** |
3273 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
3274 | * @x: holds the state of this particular completion | |
3275 | * | |
3276 | * This waits for completion of a specific task to be signaled. It is | |
3277 | * interruptible. | |
c6dc7f05 BF |
3278 | * |
3279 | * The return value is -ERESTARTSYS if interrupted, 0 if completed. | |
65eb3dc6 | 3280 | */ |
8cbbe86d | 3281 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 3282 | { |
51e97990 AK |
3283 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
3284 | if (t == -ERESTARTSYS) | |
3285 | return t; | |
3286 | return 0; | |
0fec171c | 3287 | } |
8cbbe86d | 3288 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 3289 | |
65eb3dc6 KD |
3290 | /** |
3291 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
3292 | * @x: holds the state of this particular completion | |
3293 | * @timeout: timeout value in jiffies | |
3294 | * | |
3295 | * This waits for either a completion of a specific task to be signaled or for a | |
3296 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
c6dc7f05 BF |
3297 | * |
3298 | * The return value is -ERESTARTSYS if interrupted, 0 if timed out, | |
3299 | * positive (at least 1, or number of jiffies left till timeout) if completed. | |
65eb3dc6 | 3300 | */ |
6bf41237 | 3301 | long __sched |
8cbbe86d AK |
3302 | wait_for_completion_interruptible_timeout(struct completion *x, |
3303 | unsigned long timeout) | |
0fec171c | 3304 | { |
8cbbe86d | 3305 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 3306 | } |
8cbbe86d | 3307 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 3308 | |
65eb3dc6 KD |
3309 | /** |
3310 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
3311 | * @x: holds the state of this particular completion | |
3312 | * | |
3313 | * This waits to be signaled for completion of a specific task. It can be | |
3314 | * interrupted by a kill signal. | |
c6dc7f05 BF |
3315 | * |
3316 | * The return value is -ERESTARTSYS if interrupted, 0 if completed. | |
65eb3dc6 | 3317 | */ |
009e577e MW |
3318 | int __sched wait_for_completion_killable(struct completion *x) |
3319 | { | |
3320 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
3321 | if (t == -ERESTARTSYS) | |
3322 | return t; | |
3323 | return 0; | |
3324 | } | |
3325 | EXPORT_SYMBOL(wait_for_completion_killable); | |
3326 | ||
0aa12fb4 SW |
3327 | /** |
3328 | * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) | |
3329 | * @x: holds the state of this particular completion | |
3330 | * @timeout: timeout value in jiffies | |
3331 | * | |
3332 | * This waits for either a completion of a specific task to be | |
3333 | * signaled or for a specified timeout to expire. It can be | |
3334 | * interrupted by a kill signal. The timeout is in jiffies. | |
c6dc7f05 BF |
3335 | * |
3336 | * The return value is -ERESTARTSYS if interrupted, 0 if timed out, | |
3337 | * positive (at least 1, or number of jiffies left till timeout) if completed. | |
0aa12fb4 | 3338 | */ |
6bf41237 | 3339 | long __sched |
0aa12fb4 SW |
3340 | wait_for_completion_killable_timeout(struct completion *x, |
3341 | unsigned long timeout) | |
3342 | { | |
3343 | return wait_for_common(x, timeout, TASK_KILLABLE); | |
3344 | } | |
3345 | EXPORT_SYMBOL(wait_for_completion_killable_timeout); | |
3346 | ||
be4de352 DC |
3347 | /** |
3348 | * try_wait_for_completion - try to decrement a completion without blocking | |
3349 | * @x: completion structure | |
3350 | * | |
3351 | * Returns: 0 if a decrement cannot be done without blocking | |
3352 | * 1 if a decrement succeeded. | |
3353 | * | |
3354 | * If a completion is being used as a counting completion, | |
3355 | * attempt to decrement the counter without blocking. This | |
3356 | * enables us to avoid waiting if the resource the completion | |
3357 | * is protecting is not available. | |
3358 | */ | |
3359 | bool try_wait_for_completion(struct completion *x) | |
3360 | { | |
7539a3b3 | 3361 | unsigned long flags; |
be4de352 DC |
3362 | int ret = 1; |
3363 | ||
7539a3b3 | 3364 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
3365 | if (!x->done) |
3366 | ret = 0; | |
3367 | else | |
3368 | x->done--; | |
7539a3b3 | 3369 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
3370 | return ret; |
3371 | } | |
3372 | EXPORT_SYMBOL(try_wait_for_completion); | |
3373 | ||
3374 | /** | |
3375 | * completion_done - Test to see if a completion has any waiters | |
3376 | * @x: completion structure | |
3377 | * | |
3378 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
3379 | * 1 if there are no waiters. | |
3380 | * | |
3381 | */ | |
3382 | bool completion_done(struct completion *x) | |
3383 | { | |
7539a3b3 | 3384 | unsigned long flags; |
be4de352 DC |
3385 | int ret = 1; |
3386 | ||
7539a3b3 | 3387 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
3388 | if (!x->done) |
3389 | ret = 0; | |
7539a3b3 | 3390 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
3391 | return ret; |
3392 | } | |
3393 | EXPORT_SYMBOL(completion_done); | |
3394 | ||
8cbbe86d AK |
3395 | static long __sched |
3396 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 3397 | { |
0fec171c IM |
3398 | unsigned long flags; |
3399 | wait_queue_t wait; | |
3400 | ||
3401 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 3402 | |
8cbbe86d | 3403 | __set_current_state(state); |
1da177e4 | 3404 | |
8cbbe86d AK |
3405 | spin_lock_irqsave(&q->lock, flags); |
3406 | __add_wait_queue(q, &wait); | |
3407 | spin_unlock(&q->lock); | |
3408 | timeout = schedule_timeout(timeout); | |
3409 | spin_lock_irq(&q->lock); | |
3410 | __remove_wait_queue(q, &wait); | |
3411 | spin_unlock_irqrestore(&q->lock, flags); | |
3412 | ||
3413 | return timeout; | |
3414 | } | |
3415 | ||
3416 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
3417 | { | |
3418 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 3419 | } |
1da177e4 LT |
3420 | EXPORT_SYMBOL(interruptible_sleep_on); |
3421 | ||
0fec171c | 3422 | long __sched |
95cdf3b7 | 3423 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 3424 | { |
8cbbe86d | 3425 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 3426 | } |
1da177e4 LT |
3427 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
3428 | ||
0fec171c | 3429 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 3430 | { |
8cbbe86d | 3431 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 3432 | } |
1da177e4 LT |
3433 | EXPORT_SYMBOL(sleep_on); |
3434 | ||
0fec171c | 3435 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 3436 | { |
8cbbe86d | 3437 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 3438 | } |
1da177e4 LT |
3439 | EXPORT_SYMBOL(sleep_on_timeout); |
3440 | ||
b29739f9 IM |
3441 | #ifdef CONFIG_RT_MUTEXES |
3442 | ||
3443 | /* | |
3444 | * rt_mutex_setprio - set the current priority of a task | |
3445 | * @p: task | |
3446 | * @prio: prio value (kernel-internal form) | |
3447 | * | |
3448 | * This function changes the 'effective' priority of a task. It does | |
3449 | * not touch ->normal_prio like __setscheduler(). | |
3450 | * | |
3451 | * Used by the rt_mutex code to implement priority inheritance logic. | |
3452 | */ | |
36c8b586 | 3453 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 3454 | { |
83b699ed | 3455 | int oldprio, on_rq, running; |
70b97a7f | 3456 | struct rq *rq; |
83ab0aa0 | 3457 | const struct sched_class *prev_class; |
b29739f9 IM |
3458 | |
3459 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
3460 | ||
0122ec5b | 3461 | rq = __task_rq_lock(p); |
b29739f9 | 3462 | |
1c4dd99b TG |
3463 | /* |
3464 | * Idle task boosting is a nono in general. There is one | |
3465 | * exception, when PREEMPT_RT and NOHZ is active: | |
3466 | * | |
3467 | * The idle task calls get_next_timer_interrupt() and holds | |
3468 | * the timer wheel base->lock on the CPU and another CPU wants | |
3469 | * to access the timer (probably to cancel it). We can safely | |
3470 | * ignore the boosting request, as the idle CPU runs this code | |
3471 | * with interrupts disabled and will complete the lock | |
3472 | * protected section without being interrupted. So there is no | |
3473 | * real need to boost. | |
3474 | */ | |
3475 | if (unlikely(p == rq->idle)) { | |
3476 | WARN_ON(p != rq->curr); | |
3477 | WARN_ON(p->pi_blocked_on); | |
3478 | goto out_unlock; | |
3479 | } | |
3480 | ||
a8027073 | 3481 | trace_sched_pi_setprio(p, prio); |
d5f9f942 | 3482 | oldprio = p->prio; |
83ab0aa0 | 3483 | prev_class = p->sched_class; |
fd2f4419 | 3484 | on_rq = p->on_rq; |
051a1d1a | 3485 | running = task_current(rq, p); |
0e1f3483 | 3486 | if (on_rq) |
69be72c1 | 3487 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
3488 | if (running) |
3489 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
3490 | |
3491 | if (rt_prio(prio)) | |
3492 | p->sched_class = &rt_sched_class; | |
3493 | else | |
3494 | p->sched_class = &fair_sched_class; | |
3495 | ||
b29739f9 IM |
3496 | p->prio = prio; |
3497 | ||
0e1f3483 HS |
3498 | if (running) |
3499 | p->sched_class->set_curr_task(rq); | |
da7a735e | 3500 | if (on_rq) |
371fd7e7 | 3501 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 | 3502 | |
da7a735e | 3503 | check_class_changed(rq, p, prev_class, oldprio); |
1c4dd99b | 3504 | out_unlock: |
0122ec5b | 3505 | __task_rq_unlock(rq); |
b29739f9 | 3506 | } |
b29739f9 | 3507 | #endif |
36c8b586 | 3508 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 3509 | { |
dd41f596 | 3510 | int old_prio, delta, on_rq; |
1da177e4 | 3511 | unsigned long flags; |
70b97a7f | 3512 | struct rq *rq; |
1da177e4 LT |
3513 | |
3514 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
3515 | return; | |
3516 | /* | |
3517 | * We have to be careful, if called from sys_setpriority(), | |
3518 | * the task might be in the middle of scheduling on another CPU. | |
3519 | */ | |
3520 | rq = task_rq_lock(p, &flags); | |
3521 | /* | |
3522 | * The RT priorities are set via sched_setscheduler(), but we still | |
3523 | * allow the 'normal' nice value to be set - but as expected | |
3524 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 3525 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 3526 | */ |
e05606d3 | 3527 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
3528 | p->static_prio = NICE_TO_PRIO(nice); |
3529 | goto out_unlock; | |
3530 | } | |
fd2f4419 | 3531 | on_rq = p->on_rq; |
c09595f6 | 3532 | if (on_rq) |
69be72c1 | 3533 | dequeue_task(rq, p, 0); |
1da177e4 | 3534 | |
1da177e4 | 3535 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 3536 | set_load_weight(p); |
b29739f9 IM |
3537 | old_prio = p->prio; |
3538 | p->prio = effective_prio(p); | |
3539 | delta = p->prio - old_prio; | |
1da177e4 | 3540 | |
dd41f596 | 3541 | if (on_rq) { |
371fd7e7 | 3542 | enqueue_task(rq, p, 0); |
1da177e4 | 3543 | /* |
d5f9f942 AM |
3544 | * If the task increased its priority or is running and |
3545 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 3546 | */ |
d5f9f942 | 3547 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
3548 | resched_task(rq->curr); |
3549 | } | |
3550 | out_unlock: | |
0122ec5b | 3551 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 3552 | } |
1da177e4 LT |
3553 | EXPORT_SYMBOL(set_user_nice); |
3554 | ||
e43379f1 MM |
3555 | /* |
3556 | * can_nice - check if a task can reduce its nice value | |
3557 | * @p: task | |
3558 | * @nice: nice value | |
3559 | */ | |
36c8b586 | 3560 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 3561 | { |
024f4747 MM |
3562 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
3563 | int nice_rlim = 20 - nice; | |
48f24c4d | 3564 | |
78d7d407 | 3565 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
3566 | capable(CAP_SYS_NICE)); |
3567 | } | |
3568 | ||
1da177e4 LT |
3569 | #ifdef __ARCH_WANT_SYS_NICE |
3570 | ||
3571 | /* | |
3572 | * sys_nice - change the priority of the current process. | |
3573 | * @increment: priority increment | |
3574 | * | |
3575 | * sys_setpriority is a more generic, but much slower function that | |
3576 | * does similar things. | |
3577 | */ | |
5add95d4 | 3578 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 3579 | { |
48f24c4d | 3580 | long nice, retval; |
1da177e4 LT |
3581 | |
3582 | /* | |
3583 | * Setpriority might change our priority at the same moment. | |
3584 | * We don't have to worry. Conceptually one call occurs first | |
3585 | * and we have a single winner. | |
3586 | */ | |
e43379f1 MM |
3587 | if (increment < -40) |
3588 | increment = -40; | |
1da177e4 LT |
3589 | if (increment > 40) |
3590 | increment = 40; | |
3591 | ||
2b8f836f | 3592 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
3593 | if (nice < -20) |
3594 | nice = -20; | |
3595 | if (nice > 19) | |
3596 | nice = 19; | |
3597 | ||
e43379f1 MM |
3598 | if (increment < 0 && !can_nice(current, nice)) |
3599 | return -EPERM; | |
3600 | ||
1da177e4 LT |
3601 | retval = security_task_setnice(current, nice); |
3602 | if (retval) | |
3603 | return retval; | |
3604 | ||
3605 | set_user_nice(current, nice); | |
3606 | return 0; | |
3607 | } | |
3608 | ||
3609 | #endif | |
3610 | ||
3611 | /** | |
3612 | * task_prio - return the priority value of a given task. | |
3613 | * @p: the task in question. | |
3614 | * | |
3615 | * This is the priority value as seen by users in /proc. | |
3616 | * RT tasks are offset by -200. Normal tasks are centered | |
3617 | * around 0, value goes from -16 to +15. | |
3618 | */ | |
36c8b586 | 3619 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
3620 | { |
3621 | return p->prio - MAX_RT_PRIO; | |
3622 | } | |
3623 | ||
3624 | /** | |
3625 | * task_nice - return the nice value of a given task. | |
3626 | * @p: the task in question. | |
3627 | */ | |
36c8b586 | 3628 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
3629 | { |
3630 | return TASK_NICE(p); | |
3631 | } | |
150d8bed | 3632 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
3633 | |
3634 | /** | |
3635 | * idle_cpu - is a given cpu idle currently? | |
3636 | * @cpu: the processor in question. | |
3637 | */ | |
3638 | int idle_cpu(int cpu) | |
3639 | { | |
908a3283 TG |
3640 | struct rq *rq = cpu_rq(cpu); |
3641 | ||
3642 | if (rq->curr != rq->idle) | |
3643 | return 0; | |
3644 | ||
3645 | if (rq->nr_running) | |
3646 | return 0; | |
3647 | ||
3648 | #ifdef CONFIG_SMP | |
3649 | if (!llist_empty(&rq->wake_list)) | |
3650 | return 0; | |
3651 | #endif | |
3652 | ||
3653 | return 1; | |
1da177e4 LT |
3654 | } |
3655 | ||
1da177e4 LT |
3656 | /** |
3657 | * idle_task - return the idle task for a given cpu. | |
3658 | * @cpu: the processor in question. | |
3659 | */ | |
36c8b586 | 3660 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
3661 | { |
3662 | return cpu_rq(cpu)->idle; | |
3663 | } | |
3664 | ||
3665 | /** | |
3666 | * find_process_by_pid - find a process with a matching PID value. | |
3667 | * @pid: the pid in question. | |
3668 | */ | |
a9957449 | 3669 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 3670 | { |
228ebcbe | 3671 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
3672 | } |
3673 | ||
3674 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
3675 | static void |
3676 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 3677 | { |
1da177e4 LT |
3678 | p->policy = policy; |
3679 | p->rt_priority = prio; | |
b29739f9 IM |
3680 | p->normal_prio = normal_prio(p); |
3681 | /* we are holding p->pi_lock already */ | |
3682 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
3683 | if (rt_prio(p->prio)) |
3684 | p->sched_class = &rt_sched_class; | |
3685 | else | |
3686 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 3687 | set_load_weight(p); |
1da177e4 LT |
3688 | } |
3689 | ||
c69e8d9c DH |
3690 | /* |
3691 | * check the target process has a UID that matches the current process's | |
3692 | */ | |
3693 | static bool check_same_owner(struct task_struct *p) | |
3694 | { | |
3695 | const struct cred *cred = current_cred(), *pcred; | |
3696 | bool match; | |
3697 | ||
3698 | rcu_read_lock(); | |
3699 | pcred = __task_cred(p); | |
9c806aa0 EB |
3700 | match = (uid_eq(cred->euid, pcred->euid) || |
3701 | uid_eq(cred->euid, pcred->uid)); | |
c69e8d9c DH |
3702 | rcu_read_unlock(); |
3703 | return match; | |
3704 | } | |
3705 | ||
961ccddd | 3706 | static int __sched_setscheduler(struct task_struct *p, int policy, |
fe7de49f | 3707 | const struct sched_param *param, bool user) |
1da177e4 | 3708 | { |
83b699ed | 3709 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 3710 | unsigned long flags; |
83ab0aa0 | 3711 | const struct sched_class *prev_class; |
70b97a7f | 3712 | struct rq *rq; |
ca94c442 | 3713 | int reset_on_fork; |
1da177e4 | 3714 | |
66e5393a SR |
3715 | /* may grab non-irq protected spin_locks */ |
3716 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
3717 | recheck: |
3718 | /* double check policy once rq lock held */ | |
ca94c442 LP |
3719 | if (policy < 0) { |
3720 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 3721 | policy = oldpolicy = p->policy; |
ca94c442 LP |
3722 | } else { |
3723 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
3724 | policy &= ~SCHED_RESET_ON_FORK; | |
3725 | ||
3726 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
3727 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
3728 | policy != SCHED_IDLE) | |
3729 | return -EINVAL; | |
3730 | } | |
3731 | ||
1da177e4 LT |
3732 | /* |
3733 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
3734 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
3735 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
3736 | */ |
3737 | if (param->sched_priority < 0 || | |
95cdf3b7 | 3738 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 3739 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 3740 | return -EINVAL; |
e05606d3 | 3741 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
3742 | return -EINVAL; |
3743 | ||
37e4ab3f OC |
3744 | /* |
3745 | * Allow unprivileged RT tasks to decrease priority: | |
3746 | */ | |
961ccddd | 3747 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 3748 | if (rt_policy(policy)) { |
a44702e8 ON |
3749 | unsigned long rlim_rtprio = |
3750 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
3751 | |
3752 | /* can't set/change the rt policy */ | |
3753 | if (policy != p->policy && !rlim_rtprio) | |
3754 | return -EPERM; | |
3755 | ||
3756 | /* can't increase priority */ | |
3757 | if (param->sched_priority > p->rt_priority && | |
3758 | param->sched_priority > rlim_rtprio) | |
3759 | return -EPERM; | |
3760 | } | |
c02aa73b | 3761 | |
dd41f596 | 3762 | /* |
c02aa73b DH |
3763 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
3764 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 3765 | */ |
c02aa73b DH |
3766 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
3767 | if (!can_nice(p, TASK_NICE(p))) | |
3768 | return -EPERM; | |
3769 | } | |
5fe1d75f | 3770 | |
37e4ab3f | 3771 | /* can't change other user's priorities */ |
c69e8d9c | 3772 | if (!check_same_owner(p)) |
37e4ab3f | 3773 | return -EPERM; |
ca94c442 LP |
3774 | |
3775 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
3776 | if (p->sched_reset_on_fork && !reset_on_fork) | |
3777 | return -EPERM; | |
37e4ab3f | 3778 | } |
1da177e4 | 3779 | |
725aad24 | 3780 | if (user) { |
b0ae1981 | 3781 | retval = security_task_setscheduler(p); |
725aad24 JF |
3782 | if (retval) |
3783 | return retval; | |
3784 | } | |
3785 | ||
b29739f9 IM |
3786 | /* |
3787 | * make sure no PI-waiters arrive (or leave) while we are | |
3788 | * changing the priority of the task: | |
0122ec5b | 3789 | * |
25985edc | 3790 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
3791 | * runqueue lock must be held. |
3792 | */ | |
0122ec5b | 3793 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 3794 | |
34f971f6 PZ |
3795 | /* |
3796 | * Changing the policy of the stop threads its a very bad idea | |
3797 | */ | |
3798 | if (p == rq->stop) { | |
0122ec5b | 3799 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
3800 | return -EINVAL; |
3801 | } | |
3802 | ||
a51e9198 DF |
3803 | /* |
3804 | * If not changing anything there's no need to proceed further: | |
3805 | */ | |
3806 | if (unlikely(policy == p->policy && (!rt_policy(policy) || | |
3807 | param->sched_priority == p->rt_priority))) { | |
45afb173 | 3808 | task_rq_unlock(rq, p, &flags); |
a51e9198 DF |
3809 | return 0; |
3810 | } | |
3811 | ||
dc61b1d6 PZ |
3812 | #ifdef CONFIG_RT_GROUP_SCHED |
3813 | if (user) { | |
3814 | /* | |
3815 | * Do not allow realtime tasks into groups that have no runtime | |
3816 | * assigned. | |
3817 | */ | |
3818 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
3819 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
3820 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 3821 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
3822 | return -EPERM; |
3823 | } | |
3824 | } | |
3825 | #endif | |
3826 | ||
1da177e4 LT |
3827 | /* recheck policy now with rq lock held */ |
3828 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
3829 | policy = oldpolicy = -1; | |
0122ec5b | 3830 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
3831 | goto recheck; |
3832 | } | |
fd2f4419 | 3833 | on_rq = p->on_rq; |
051a1d1a | 3834 | running = task_current(rq, p); |
0e1f3483 | 3835 | if (on_rq) |
4ca9b72b | 3836 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
3837 | if (running) |
3838 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 3839 | |
ca94c442 LP |
3840 | p->sched_reset_on_fork = reset_on_fork; |
3841 | ||
1da177e4 | 3842 | oldprio = p->prio; |
83ab0aa0 | 3843 | prev_class = p->sched_class; |
dd41f596 | 3844 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 3845 | |
0e1f3483 HS |
3846 | if (running) |
3847 | p->sched_class->set_curr_task(rq); | |
da7a735e | 3848 | if (on_rq) |
4ca9b72b | 3849 | enqueue_task(rq, p, 0); |
cb469845 | 3850 | |
da7a735e | 3851 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 3852 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 3853 | |
95e02ca9 TG |
3854 | rt_mutex_adjust_pi(p); |
3855 | ||
1da177e4 LT |
3856 | return 0; |
3857 | } | |
961ccddd RR |
3858 | |
3859 | /** | |
3860 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
3861 | * @p: the task in question. | |
3862 | * @policy: new policy. | |
3863 | * @param: structure containing the new RT priority. | |
3864 | * | |
3865 | * NOTE that the task may be already dead. | |
3866 | */ | |
3867 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 3868 | const struct sched_param *param) |
961ccddd RR |
3869 | { |
3870 | return __sched_setscheduler(p, policy, param, true); | |
3871 | } | |
1da177e4 LT |
3872 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
3873 | ||
961ccddd RR |
3874 | /** |
3875 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
3876 | * @p: the task in question. | |
3877 | * @policy: new policy. | |
3878 | * @param: structure containing the new RT priority. | |
3879 | * | |
3880 | * Just like sched_setscheduler, only don't bother checking if the | |
3881 | * current context has permission. For example, this is needed in | |
3882 | * stop_machine(): we create temporary high priority worker threads, | |
3883 | * but our caller might not have that capability. | |
3884 | */ | |
3885 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 3886 | const struct sched_param *param) |
961ccddd RR |
3887 | { |
3888 | return __sched_setscheduler(p, policy, param, false); | |
3889 | } | |
3890 | ||
95cdf3b7 IM |
3891 | static int |
3892 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 3893 | { |
1da177e4 LT |
3894 | struct sched_param lparam; |
3895 | struct task_struct *p; | |
36c8b586 | 3896 | int retval; |
1da177e4 LT |
3897 | |
3898 | if (!param || pid < 0) | |
3899 | return -EINVAL; | |
3900 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
3901 | return -EFAULT; | |
5fe1d75f ON |
3902 | |
3903 | rcu_read_lock(); | |
3904 | retval = -ESRCH; | |
1da177e4 | 3905 | p = find_process_by_pid(pid); |
5fe1d75f ON |
3906 | if (p != NULL) |
3907 | retval = sched_setscheduler(p, policy, &lparam); | |
3908 | rcu_read_unlock(); | |
36c8b586 | 3909 | |
1da177e4 LT |
3910 | return retval; |
3911 | } | |
3912 | ||
3913 | /** | |
3914 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
3915 | * @pid: the pid in question. | |
3916 | * @policy: new policy. | |
3917 | * @param: structure containing the new RT priority. | |
3918 | */ | |
5add95d4 HC |
3919 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
3920 | struct sched_param __user *, param) | |
1da177e4 | 3921 | { |
c21761f1 JB |
3922 | /* negative values for policy are not valid */ |
3923 | if (policy < 0) | |
3924 | return -EINVAL; | |
3925 | ||
1da177e4 LT |
3926 | return do_sched_setscheduler(pid, policy, param); |
3927 | } | |
3928 | ||
3929 | /** | |
3930 | * sys_sched_setparam - set/change the RT priority of a thread | |
3931 | * @pid: the pid in question. | |
3932 | * @param: structure containing the new RT priority. | |
3933 | */ | |
5add95d4 | 3934 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
3935 | { |
3936 | return do_sched_setscheduler(pid, -1, param); | |
3937 | } | |
3938 | ||
3939 | /** | |
3940 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
3941 | * @pid: the pid in question. | |
3942 | */ | |
5add95d4 | 3943 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 3944 | { |
36c8b586 | 3945 | struct task_struct *p; |
3a5c359a | 3946 | int retval; |
1da177e4 LT |
3947 | |
3948 | if (pid < 0) | |
3a5c359a | 3949 | return -EINVAL; |
1da177e4 LT |
3950 | |
3951 | retval = -ESRCH; | |
5fe85be0 | 3952 | rcu_read_lock(); |
1da177e4 LT |
3953 | p = find_process_by_pid(pid); |
3954 | if (p) { | |
3955 | retval = security_task_getscheduler(p); | |
3956 | if (!retval) | |
ca94c442 LP |
3957 | retval = p->policy |
3958 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 3959 | } |
5fe85be0 | 3960 | rcu_read_unlock(); |
1da177e4 LT |
3961 | return retval; |
3962 | } | |
3963 | ||
3964 | /** | |
ca94c442 | 3965 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
3966 | * @pid: the pid in question. |
3967 | * @param: structure containing the RT priority. | |
3968 | */ | |
5add95d4 | 3969 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
3970 | { |
3971 | struct sched_param lp; | |
36c8b586 | 3972 | struct task_struct *p; |
3a5c359a | 3973 | int retval; |
1da177e4 LT |
3974 | |
3975 | if (!param || pid < 0) | |
3a5c359a | 3976 | return -EINVAL; |
1da177e4 | 3977 | |
5fe85be0 | 3978 | rcu_read_lock(); |
1da177e4 LT |
3979 | p = find_process_by_pid(pid); |
3980 | retval = -ESRCH; | |
3981 | if (!p) | |
3982 | goto out_unlock; | |
3983 | ||
3984 | retval = security_task_getscheduler(p); | |
3985 | if (retval) | |
3986 | goto out_unlock; | |
3987 | ||
3988 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 3989 | rcu_read_unlock(); |
1da177e4 LT |
3990 | |
3991 | /* | |
3992 | * This one might sleep, we cannot do it with a spinlock held ... | |
3993 | */ | |
3994 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
3995 | ||
1da177e4 LT |
3996 | return retval; |
3997 | ||
3998 | out_unlock: | |
5fe85be0 | 3999 | rcu_read_unlock(); |
1da177e4 LT |
4000 | return retval; |
4001 | } | |
4002 | ||
96f874e2 | 4003 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4004 | { |
5a16f3d3 | 4005 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4006 | struct task_struct *p; |
4007 | int retval; | |
1da177e4 | 4008 | |
95402b38 | 4009 | get_online_cpus(); |
23f5d142 | 4010 | rcu_read_lock(); |
1da177e4 LT |
4011 | |
4012 | p = find_process_by_pid(pid); | |
4013 | if (!p) { | |
23f5d142 | 4014 | rcu_read_unlock(); |
95402b38 | 4015 | put_online_cpus(); |
1da177e4 LT |
4016 | return -ESRCH; |
4017 | } | |
4018 | ||
23f5d142 | 4019 | /* Prevent p going away */ |
1da177e4 | 4020 | get_task_struct(p); |
23f5d142 | 4021 | rcu_read_unlock(); |
1da177e4 | 4022 | |
5a16f3d3 RR |
4023 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4024 | retval = -ENOMEM; | |
4025 | goto out_put_task; | |
4026 | } | |
4027 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4028 | retval = -ENOMEM; | |
4029 | goto out_free_cpus_allowed; | |
4030 | } | |
1da177e4 | 4031 | retval = -EPERM; |
f1c84dae | 4032 | if (!check_same_owner(p) && !ns_capable(task_user_ns(p), CAP_SYS_NICE)) |
1da177e4 LT |
4033 | goto out_unlock; |
4034 | ||
b0ae1981 | 4035 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
4036 | if (retval) |
4037 | goto out_unlock; | |
4038 | ||
5a16f3d3 RR |
4039 | cpuset_cpus_allowed(p, cpus_allowed); |
4040 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
49246274 | 4041 | again: |
5a16f3d3 | 4042 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4043 | |
8707d8b8 | 4044 | if (!retval) { |
5a16f3d3 RR |
4045 | cpuset_cpus_allowed(p, cpus_allowed); |
4046 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4047 | /* |
4048 | * We must have raced with a concurrent cpuset | |
4049 | * update. Just reset the cpus_allowed to the | |
4050 | * cpuset's cpus_allowed | |
4051 | */ | |
5a16f3d3 | 4052 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4053 | goto again; |
4054 | } | |
4055 | } | |
1da177e4 | 4056 | out_unlock: |
5a16f3d3 RR |
4057 | free_cpumask_var(new_mask); |
4058 | out_free_cpus_allowed: | |
4059 | free_cpumask_var(cpus_allowed); | |
4060 | out_put_task: | |
1da177e4 | 4061 | put_task_struct(p); |
95402b38 | 4062 | put_online_cpus(); |
1da177e4 LT |
4063 | return retval; |
4064 | } | |
4065 | ||
4066 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4067 | struct cpumask *new_mask) |
1da177e4 | 4068 | { |
96f874e2 RR |
4069 | if (len < cpumask_size()) |
4070 | cpumask_clear(new_mask); | |
4071 | else if (len > cpumask_size()) | |
4072 | len = cpumask_size(); | |
4073 | ||
1da177e4 LT |
4074 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4075 | } | |
4076 | ||
4077 | /** | |
4078 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4079 | * @pid: pid of the process | |
4080 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4081 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
4082 | */ | |
5add95d4 HC |
4083 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4084 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4085 | { |
5a16f3d3 | 4086 | cpumask_var_t new_mask; |
1da177e4 LT |
4087 | int retval; |
4088 | ||
5a16f3d3 RR |
4089 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4090 | return -ENOMEM; | |
1da177e4 | 4091 | |
5a16f3d3 RR |
4092 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4093 | if (retval == 0) | |
4094 | retval = sched_setaffinity(pid, new_mask); | |
4095 | free_cpumask_var(new_mask); | |
4096 | return retval; | |
1da177e4 LT |
4097 | } |
4098 | ||
96f874e2 | 4099 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4100 | { |
36c8b586 | 4101 | struct task_struct *p; |
31605683 | 4102 | unsigned long flags; |
1da177e4 | 4103 | int retval; |
1da177e4 | 4104 | |
95402b38 | 4105 | get_online_cpus(); |
23f5d142 | 4106 | rcu_read_lock(); |
1da177e4 LT |
4107 | |
4108 | retval = -ESRCH; | |
4109 | p = find_process_by_pid(pid); | |
4110 | if (!p) | |
4111 | goto out_unlock; | |
4112 | ||
e7834f8f DQ |
4113 | retval = security_task_getscheduler(p); |
4114 | if (retval) | |
4115 | goto out_unlock; | |
4116 | ||
013fdb80 | 4117 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
96f874e2 | 4118 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
013fdb80 | 4119 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4120 | |
4121 | out_unlock: | |
23f5d142 | 4122 | rcu_read_unlock(); |
95402b38 | 4123 | put_online_cpus(); |
1da177e4 | 4124 | |
9531b62f | 4125 | return retval; |
1da177e4 LT |
4126 | } |
4127 | ||
4128 | /** | |
4129 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4130 | * @pid: pid of the process | |
4131 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4132 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
4133 | */ | |
5add95d4 HC |
4134 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4135 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4136 | { |
4137 | int ret; | |
f17c8607 | 4138 | cpumask_var_t mask; |
1da177e4 | 4139 | |
84fba5ec | 4140 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4141 | return -EINVAL; |
4142 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4143 | return -EINVAL; |
4144 | ||
f17c8607 RR |
4145 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4146 | return -ENOMEM; | |
1da177e4 | 4147 | |
f17c8607 RR |
4148 | ret = sched_getaffinity(pid, mask); |
4149 | if (ret == 0) { | |
8bc037fb | 4150 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4151 | |
4152 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4153 | ret = -EFAULT; |
4154 | else | |
cd3d8031 | 4155 | ret = retlen; |
f17c8607 RR |
4156 | } |
4157 | free_cpumask_var(mask); | |
1da177e4 | 4158 | |
f17c8607 | 4159 | return ret; |
1da177e4 LT |
4160 | } |
4161 | ||
4162 | /** | |
4163 | * sys_sched_yield - yield the current processor to other threads. | |
4164 | * | |
dd41f596 IM |
4165 | * This function yields the current CPU to other tasks. If there are no |
4166 | * other threads running on this CPU then this function will return. | |
1da177e4 | 4167 | */ |
5add95d4 | 4168 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4169 | { |
70b97a7f | 4170 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4171 | |
2d72376b | 4172 | schedstat_inc(rq, yld_count); |
4530d7ab | 4173 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4174 | |
4175 | /* | |
4176 | * Since we are going to call schedule() anyway, there's | |
4177 | * no need to preempt or enable interrupts: | |
4178 | */ | |
4179 | __release(rq->lock); | |
8a25d5de | 4180 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4181 | do_raw_spin_unlock(&rq->lock); |
ba74c144 | 4182 | sched_preempt_enable_no_resched(); |
1da177e4 LT |
4183 | |
4184 | schedule(); | |
4185 | ||
4186 | return 0; | |
4187 | } | |
4188 | ||
d86ee480 PZ |
4189 | static inline int should_resched(void) |
4190 | { | |
4191 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
4192 | } | |
4193 | ||
e7b38404 | 4194 | static void __cond_resched(void) |
1da177e4 | 4195 | { |
e7aaaa69 | 4196 | add_preempt_count(PREEMPT_ACTIVE); |
c259e01a | 4197 | __schedule(); |
e7aaaa69 | 4198 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 LT |
4199 | } |
4200 | ||
02b67cc3 | 4201 | int __sched _cond_resched(void) |
1da177e4 | 4202 | { |
d86ee480 | 4203 | if (should_resched()) { |
1da177e4 LT |
4204 | __cond_resched(); |
4205 | return 1; | |
4206 | } | |
4207 | return 0; | |
4208 | } | |
02b67cc3 | 4209 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4210 | |
4211 | /* | |
613afbf8 | 4212 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4213 | * call schedule, and on return reacquire the lock. |
4214 | * | |
41a2d6cf | 4215 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4216 | * operations here to prevent schedule() from being called twice (once via |
4217 | * spin_unlock(), once by hand). | |
4218 | */ | |
613afbf8 | 4219 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4220 | { |
d86ee480 | 4221 | int resched = should_resched(); |
6df3cecb JK |
4222 | int ret = 0; |
4223 | ||
f607c668 PZ |
4224 | lockdep_assert_held(lock); |
4225 | ||
95c354fe | 4226 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 4227 | spin_unlock(lock); |
d86ee480 | 4228 | if (resched) |
95c354fe NP |
4229 | __cond_resched(); |
4230 | else | |
4231 | cpu_relax(); | |
6df3cecb | 4232 | ret = 1; |
1da177e4 | 4233 | spin_lock(lock); |
1da177e4 | 4234 | } |
6df3cecb | 4235 | return ret; |
1da177e4 | 4236 | } |
613afbf8 | 4237 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4238 | |
613afbf8 | 4239 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4240 | { |
4241 | BUG_ON(!in_softirq()); | |
4242 | ||
d86ee480 | 4243 | if (should_resched()) { |
98d82567 | 4244 | local_bh_enable(); |
1da177e4 LT |
4245 | __cond_resched(); |
4246 | local_bh_disable(); | |
4247 | return 1; | |
4248 | } | |
4249 | return 0; | |
4250 | } | |
613afbf8 | 4251 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4252 | |
1da177e4 LT |
4253 | /** |
4254 | * yield - yield the current processor to other threads. | |
4255 | * | |
8e3fabfd PZ |
4256 | * Do not ever use this function, there's a 99% chance you're doing it wrong. |
4257 | * | |
4258 | * The scheduler is at all times free to pick the calling task as the most | |
4259 | * eligible task to run, if removing the yield() call from your code breaks | |
4260 | * it, its already broken. | |
4261 | * | |
4262 | * Typical broken usage is: | |
4263 | * | |
4264 | * while (!event) | |
4265 | * yield(); | |
4266 | * | |
4267 | * where one assumes that yield() will let 'the other' process run that will | |
4268 | * make event true. If the current task is a SCHED_FIFO task that will never | |
4269 | * happen. Never use yield() as a progress guarantee!! | |
4270 | * | |
4271 | * If you want to use yield() to wait for something, use wait_event(). | |
4272 | * If you want to use yield() to be 'nice' for others, use cond_resched(). | |
4273 | * If you still want to use yield(), do not! | |
1da177e4 LT |
4274 | */ |
4275 | void __sched yield(void) | |
4276 | { | |
4277 | set_current_state(TASK_RUNNING); | |
4278 | sys_sched_yield(); | |
4279 | } | |
1da177e4 LT |
4280 | EXPORT_SYMBOL(yield); |
4281 | ||
d95f4122 MG |
4282 | /** |
4283 | * yield_to - yield the current processor to another thread in | |
4284 | * your thread group, or accelerate that thread toward the | |
4285 | * processor it's on. | |
16addf95 RD |
4286 | * @p: target task |
4287 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
4288 | * |
4289 | * It's the caller's job to ensure that the target task struct | |
4290 | * can't go away on us before we can do any checks. | |
4291 | * | |
4292 | * Returns true if we indeed boosted the target task. | |
4293 | */ | |
4294 | bool __sched yield_to(struct task_struct *p, bool preempt) | |
4295 | { | |
4296 | struct task_struct *curr = current; | |
4297 | struct rq *rq, *p_rq; | |
4298 | unsigned long flags; | |
4299 | bool yielded = 0; | |
4300 | ||
4301 | local_irq_save(flags); | |
4302 | rq = this_rq(); | |
4303 | ||
4304 | again: | |
4305 | p_rq = task_rq(p); | |
4306 | double_rq_lock(rq, p_rq); | |
4307 | while (task_rq(p) != p_rq) { | |
4308 | double_rq_unlock(rq, p_rq); | |
4309 | goto again; | |
4310 | } | |
4311 | ||
4312 | if (!curr->sched_class->yield_to_task) | |
4313 | goto out; | |
4314 | ||
4315 | if (curr->sched_class != p->sched_class) | |
4316 | goto out; | |
4317 | ||
4318 | if (task_running(p_rq, p) || p->state) | |
4319 | goto out; | |
4320 | ||
4321 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 4322 | if (yielded) { |
d95f4122 | 4323 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
4324 | /* |
4325 | * Make p's CPU reschedule; pick_next_entity takes care of | |
4326 | * fairness. | |
4327 | */ | |
4328 | if (preempt && rq != p_rq) | |
4329 | resched_task(p_rq->curr); | |
4330 | } | |
d95f4122 MG |
4331 | |
4332 | out: | |
4333 | double_rq_unlock(rq, p_rq); | |
4334 | local_irq_restore(flags); | |
4335 | ||
4336 | if (yielded) | |
4337 | schedule(); | |
4338 | ||
4339 | return yielded; | |
4340 | } | |
4341 | EXPORT_SYMBOL_GPL(yield_to); | |
4342 | ||
1da177e4 | 4343 | /* |
41a2d6cf | 4344 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4345 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4346 | */ |
4347 | void __sched io_schedule(void) | |
4348 | { | |
54d35f29 | 4349 | struct rq *rq = raw_rq(); |
1da177e4 | 4350 | |
0ff92245 | 4351 | delayacct_blkio_start(); |
1da177e4 | 4352 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4353 | blk_flush_plug(current); |
8f0dfc34 | 4354 | current->in_iowait = 1; |
1da177e4 | 4355 | schedule(); |
8f0dfc34 | 4356 | current->in_iowait = 0; |
1da177e4 | 4357 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4358 | delayacct_blkio_end(); |
1da177e4 | 4359 | } |
1da177e4 LT |
4360 | EXPORT_SYMBOL(io_schedule); |
4361 | ||
4362 | long __sched io_schedule_timeout(long timeout) | |
4363 | { | |
54d35f29 | 4364 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4365 | long ret; |
4366 | ||
0ff92245 | 4367 | delayacct_blkio_start(); |
1da177e4 | 4368 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4369 | blk_flush_plug(current); |
8f0dfc34 | 4370 | current->in_iowait = 1; |
1da177e4 | 4371 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4372 | current->in_iowait = 0; |
1da177e4 | 4373 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4374 | delayacct_blkio_end(); |
1da177e4 LT |
4375 | return ret; |
4376 | } | |
4377 | ||
4378 | /** | |
4379 | * sys_sched_get_priority_max - return maximum RT priority. | |
4380 | * @policy: scheduling class. | |
4381 | * | |
4382 | * this syscall returns the maximum rt_priority that can be used | |
4383 | * by a given scheduling class. | |
4384 | */ | |
5add95d4 | 4385 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4386 | { |
4387 | int ret = -EINVAL; | |
4388 | ||
4389 | switch (policy) { | |
4390 | case SCHED_FIFO: | |
4391 | case SCHED_RR: | |
4392 | ret = MAX_USER_RT_PRIO-1; | |
4393 | break; | |
4394 | case SCHED_NORMAL: | |
b0a9499c | 4395 | case SCHED_BATCH: |
dd41f596 | 4396 | case SCHED_IDLE: |
1da177e4 LT |
4397 | ret = 0; |
4398 | break; | |
4399 | } | |
4400 | return ret; | |
4401 | } | |
4402 | ||
4403 | /** | |
4404 | * sys_sched_get_priority_min - return minimum RT priority. | |
4405 | * @policy: scheduling class. | |
4406 | * | |
4407 | * this syscall returns the minimum rt_priority that can be used | |
4408 | * by a given scheduling class. | |
4409 | */ | |
5add95d4 | 4410 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
4411 | { |
4412 | int ret = -EINVAL; | |
4413 | ||
4414 | switch (policy) { | |
4415 | case SCHED_FIFO: | |
4416 | case SCHED_RR: | |
4417 | ret = 1; | |
4418 | break; | |
4419 | case SCHED_NORMAL: | |
b0a9499c | 4420 | case SCHED_BATCH: |
dd41f596 | 4421 | case SCHED_IDLE: |
1da177e4 LT |
4422 | ret = 0; |
4423 | } | |
4424 | return ret; | |
4425 | } | |
4426 | ||
4427 | /** | |
4428 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
4429 | * @pid: pid of the process. | |
4430 | * @interval: userspace pointer to the timeslice value. | |
4431 | * | |
4432 | * this syscall writes the default timeslice value of a given process | |
4433 | * into the user-space timespec buffer. A value of '0' means infinity. | |
4434 | */ | |
17da2bd9 | 4435 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 4436 | struct timespec __user *, interval) |
1da177e4 | 4437 | { |
36c8b586 | 4438 | struct task_struct *p; |
a4ec24b4 | 4439 | unsigned int time_slice; |
dba091b9 TG |
4440 | unsigned long flags; |
4441 | struct rq *rq; | |
3a5c359a | 4442 | int retval; |
1da177e4 | 4443 | struct timespec t; |
1da177e4 LT |
4444 | |
4445 | if (pid < 0) | |
3a5c359a | 4446 | return -EINVAL; |
1da177e4 LT |
4447 | |
4448 | retval = -ESRCH; | |
1a551ae7 | 4449 | rcu_read_lock(); |
1da177e4 LT |
4450 | p = find_process_by_pid(pid); |
4451 | if (!p) | |
4452 | goto out_unlock; | |
4453 | ||
4454 | retval = security_task_getscheduler(p); | |
4455 | if (retval) | |
4456 | goto out_unlock; | |
4457 | ||
dba091b9 TG |
4458 | rq = task_rq_lock(p, &flags); |
4459 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 4460 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 4461 | |
1a551ae7 | 4462 | rcu_read_unlock(); |
a4ec24b4 | 4463 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 4464 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 4465 | return retval; |
3a5c359a | 4466 | |
1da177e4 | 4467 | out_unlock: |
1a551ae7 | 4468 | rcu_read_unlock(); |
1da177e4 LT |
4469 | return retval; |
4470 | } | |
4471 | ||
7c731e0a | 4472 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 4473 | |
82a1fcb9 | 4474 | void sched_show_task(struct task_struct *p) |
1da177e4 | 4475 | { |
1da177e4 | 4476 | unsigned long free = 0; |
36c8b586 | 4477 | unsigned state; |
1da177e4 | 4478 | |
1da177e4 | 4479 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 4480 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 4481 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 4482 | #if BITS_PER_LONG == 32 |
1da177e4 | 4483 | if (state == TASK_RUNNING) |
3df0fc5b | 4484 | printk(KERN_CONT " running "); |
1da177e4 | 4485 | else |
3df0fc5b | 4486 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
4487 | #else |
4488 | if (state == TASK_RUNNING) | |
3df0fc5b | 4489 | printk(KERN_CONT " running task "); |
1da177e4 | 4490 | else |
3df0fc5b | 4491 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
4492 | #endif |
4493 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 4494 | free = stack_not_used(p); |
1da177e4 | 4495 | #endif |
3df0fc5b | 4496 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
07cde260 | 4497 | task_pid_nr(p), task_pid_nr(rcu_dereference(p->real_parent)), |
aa47b7e0 | 4498 | (unsigned long)task_thread_info(p)->flags); |
1da177e4 | 4499 | |
5fb5e6de | 4500 | show_stack(p, NULL); |
1da177e4 LT |
4501 | } |
4502 | ||
e59e2ae2 | 4503 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 4504 | { |
36c8b586 | 4505 | struct task_struct *g, *p; |
1da177e4 | 4506 | |
4bd77321 | 4507 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
4508 | printk(KERN_INFO |
4509 | " task PC stack pid father\n"); | |
1da177e4 | 4510 | #else |
3df0fc5b PZ |
4511 | printk(KERN_INFO |
4512 | " task PC stack pid father\n"); | |
1da177e4 | 4513 | #endif |
510f5acc | 4514 | rcu_read_lock(); |
1da177e4 LT |
4515 | do_each_thread(g, p) { |
4516 | /* | |
4517 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 4518 | * console might take a lot of time: |
1da177e4 LT |
4519 | */ |
4520 | touch_nmi_watchdog(); | |
39bc89fd | 4521 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 4522 | sched_show_task(p); |
1da177e4 LT |
4523 | } while_each_thread(g, p); |
4524 | ||
04c9167f JF |
4525 | touch_all_softlockup_watchdogs(); |
4526 | ||
dd41f596 IM |
4527 | #ifdef CONFIG_SCHED_DEBUG |
4528 | sysrq_sched_debug_show(); | |
4529 | #endif | |
510f5acc | 4530 | rcu_read_unlock(); |
e59e2ae2 IM |
4531 | /* |
4532 | * Only show locks if all tasks are dumped: | |
4533 | */ | |
93335a21 | 4534 | if (!state_filter) |
e59e2ae2 | 4535 | debug_show_all_locks(); |
1da177e4 LT |
4536 | } |
4537 | ||
1df21055 IM |
4538 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
4539 | { | |
dd41f596 | 4540 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
4541 | } |
4542 | ||
f340c0d1 IM |
4543 | /** |
4544 | * init_idle - set up an idle thread for a given CPU | |
4545 | * @idle: task in question | |
4546 | * @cpu: cpu the idle task belongs to | |
4547 | * | |
4548 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
4549 | * flag, to make booting more robust. | |
4550 | */ | |
5c1e1767 | 4551 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 4552 | { |
70b97a7f | 4553 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
4554 | unsigned long flags; |
4555 | ||
05fa785c | 4556 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 4557 | |
dd41f596 | 4558 | __sched_fork(idle); |
06b83b5f | 4559 | idle->state = TASK_RUNNING; |
dd41f596 IM |
4560 | idle->se.exec_start = sched_clock(); |
4561 | ||
1e1b6c51 | 4562 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
4563 | /* |
4564 | * We're having a chicken and egg problem, even though we are | |
4565 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
4566 | * lockdep check in task_group() will fail. | |
4567 | * | |
4568 | * Similar case to sched_fork(). / Alternatively we could | |
4569 | * use task_rq_lock() here and obtain the other rq->lock. | |
4570 | * | |
4571 | * Silence PROVE_RCU | |
4572 | */ | |
4573 | rcu_read_lock(); | |
dd41f596 | 4574 | __set_task_cpu(idle, cpu); |
6506cf6c | 4575 | rcu_read_unlock(); |
1da177e4 | 4576 | |
1da177e4 | 4577 | rq->curr = rq->idle = idle; |
3ca7a440 PZ |
4578 | #if defined(CONFIG_SMP) |
4579 | idle->on_cpu = 1; | |
4866cde0 | 4580 | #endif |
05fa785c | 4581 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
4582 | |
4583 | /* Set the preempt count _outside_ the spinlocks! */ | |
a1261f54 | 4584 | task_thread_info(idle)->preempt_count = 0; |
55cd5340 | 4585 | |
dd41f596 IM |
4586 | /* |
4587 | * The idle tasks have their own, simple scheduling class: | |
4588 | */ | |
4589 | idle->sched_class = &idle_sched_class; | |
868baf07 | 4590 | ftrace_graph_init_idle_task(idle, cpu); |
f1c6f1a7 CE |
4591 | #if defined(CONFIG_SMP) |
4592 | sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); | |
4593 | #endif | |
19978ca6 IM |
4594 | } |
4595 | ||
1da177e4 | 4596 | #ifdef CONFIG_SMP |
1e1b6c51 KM |
4597 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
4598 | { | |
4599 | if (p->sched_class && p->sched_class->set_cpus_allowed) | |
4600 | p->sched_class->set_cpus_allowed(p, new_mask); | |
4939602a PZ |
4601 | |
4602 | cpumask_copy(&p->cpus_allowed, new_mask); | |
29baa747 | 4603 | p->nr_cpus_allowed = cpumask_weight(new_mask); |
1e1b6c51 KM |
4604 | } |
4605 | ||
1da177e4 LT |
4606 | /* |
4607 | * This is how migration works: | |
4608 | * | |
969c7921 TH |
4609 | * 1) we invoke migration_cpu_stop() on the target CPU using |
4610 | * stop_one_cpu(). | |
4611 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
4612 | * off the CPU) | |
4613 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
4614 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 4615 | * it and puts it into the right queue. |
969c7921 TH |
4616 | * 5) stopper completes and stop_one_cpu() returns and the migration |
4617 | * is done. | |
1da177e4 LT |
4618 | */ |
4619 | ||
4620 | /* | |
4621 | * Change a given task's CPU affinity. Migrate the thread to a | |
4622 | * proper CPU and schedule it away if the CPU it's executing on | |
4623 | * is removed from the allowed bitmask. | |
4624 | * | |
4625 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 4626 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
4627 | * call is not atomic; no spinlocks may be held. |
4628 | */ | |
96f874e2 | 4629 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
4630 | { |
4631 | unsigned long flags; | |
70b97a7f | 4632 | struct rq *rq; |
969c7921 | 4633 | unsigned int dest_cpu; |
48f24c4d | 4634 | int ret = 0; |
1da177e4 LT |
4635 | |
4636 | rq = task_rq_lock(p, &flags); | |
e2912009 | 4637 | |
db44fc01 YZ |
4638 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
4639 | goto out; | |
4640 | ||
6ad4c188 | 4641 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
4642 | ret = -EINVAL; |
4643 | goto out; | |
4644 | } | |
4645 | ||
db44fc01 | 4646 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { |
9985b0ba DR |
4647 | ret = -EINVAL; |
4648 | goto out; | |
4649 | } | |
4650 | ||
1e1b6c51 | 4651 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 4652 | |
1da177e4 | 4653 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 4654 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
4655 | goto out; |
4656 | ||
969c7921 | 4657 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 4658 | if (p->on_rq) { |
969c7921 | 4659 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 4660 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 4661 | task_rq_unlock(rq, p, &flags); |
969c7921 | 4662 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
4663 | tlb_migrate_finish(p->mm); |
4664 | return 0; | |
4665 | } | |
4666 | out: | |
0122ec5b | 4667 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 4668 | |
1da177e4 LT |
4669 | return ret; |
4670 | } | |
cd8ba7cd | 4671 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
4672 | |
4673 | /* | |
41a2d6cf | 4674 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
4675 | * this because either it can't run here any more (set_cpus_allowed() |
4676 | * away from this CPU, or CPU going down), or because we're | |
4677 | * attempting to rebalance this task on exec (sched_exec). | |
4678 | * | |
4679 | * So we race with normal scheduler movements, but that's OK, as long | |
4680 | * as the task is no longer on this CPU. | |
efc30814 KK |
4681 | * |
4682 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 4683 | */ |
efc30814 | 4684 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 4685 | { |
70b97a7f | 4686 | struct rq *rq_dest, *rq_src; |
e2912009 | 4687 | int ret = 0; |
1da177e4 | 4688 | |
e761b772 | 4689 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 4690 | return ret; |
1da177e4 LT |
4691 | |
4692 | rq_src = cpu_rq(src_cpu); | |
4693 | rq_dest = cpu_rq(dest_cpu); | |
4694 | ||
0122ec5b | 4695 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
4696 | double_rq_lock(rq_src, rq_dest); |
4697 | /* Already moved. */ | |
4698 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 4699 | goto done; |
1da177e4 | 4700 | /* Affinity changed (again). */ |
fa17b507 | 4701 | if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
b1e38734 | 4702 | goto fail; |
1da177e4 | 4703 | |
e2912009 PZ |
4704 | /* |
4705 | * If we're not on a rq, the next wake-up will ensure we're | |
4706 | * placed properly. | |
4707 | */ | |
fd2f4419 | 4708 | if (p->on_rq) { |
4ca9b72b | 4709 | dequeue_task(rq_src, p, 0); |
e2912009 | 4710 | set_task_cpu(p, dest_cpu); |
4ca9b72b | 4711 | enqueue_task(rq_dest, p, 0); |
15afe09b | 4712 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 4713 | } |
b1e38734 | 4714 | done: |
efc30814 | 4715 | ret = 1; |
b1e38734 | 4716 | fail: |
1da177e4 | 4717 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 4718 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 4719 | return ret; |
1da177e4 LT |
4720 | } |
4721 | ||
4722 | /* | |
969c7921 TH |
4723 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
4724 | * and performs thread migration by bumping thread off CPU then | |
4725 | * 'pushing' onto another runqueue. | |
1da177e4 | 4726 | */ |
969c7921 | 4727 | static int migration_cpu_stop(void *data) |
1da177e4 | 4728 | { |
969c7921 | 4729 | struct migration_arg *arg = data; |
f7b4cddc | 4730 | |
969c7921 TH |
4731 | /* |
4732 | * The original target cpu might have gone down and we might | |
4733 | * be on another cpu but it doesn't matter. | |
4734 | */ | |
f7b4cddc | 4735 | local_irq_disable(); |
969c7921 | 4736 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 4737 | local_irq_enable(); |
1da177e4 | 4738 | return 0; |
f7b4cddc ON |
4739 | } |
4740 | ||
1da177e4 | 4741 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 4742 | |
054b9108 | 4743 | /* |
48c5ccae PZ |
4744 | * Ensures that the idle task is using init_mm right before its cpu goes |
4745 | * offline. | |
054b9108 | 4746 | */ |
48c5ccae | 4747 | void idle_task_exit(void) |
1da177e4 | 4748 | { |
48c5ccae | 4749 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 4750 | |
48c5ccae | 4751 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 4752 | |
48c5ccae PZ |
4753 | if (mm != &init_mm) |
4754 | switch_mm(mm, &init_mm, current); | |
4755 | mmdrop(mm); | |
1da177e4 LT |
4756 | } |
4757 | ||
4758 | /* | |
5d180232 PZ |
4759 | * Since this CPU is going 'away' for a while, fold any nr_active delta |
4760 | * we might have. Assumes we're called after migrate_tasks() so that the | |
4761 | * nr_active count is stable. | |
4762 | * | |
4763 | * Also see the comment "Global load-average calculations". | |
1da177e4 | 4764 | */ |
5d180232 | 4765 | static void calc_load_migrate(struct rq *rq) |
1da177e4 | 4766 | { |
5d180232 PZ |
4767 | long delta = calc_load_fold_active(rq); |
4768 | if (delta) | |
4769 | atomic_long_add(delta, &calc_load_tasks); | |
1da177e4 LT |
4770 | } |
4771 | ||
48f24c4d | 4772 | /* |
48c5ccae PZ |
4773 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
4774 | * try_to_wake_up()->select_task_rq(). | |
4775 | * | |
4776 | * Called with rq->lock held even though we'er in stop_machine() and | |
4777 | * there's no concurrency possible, we hold the required locks anyway | |
4778 | * because of lock validation efforts. | |
1da177e4 | 4779 | */ |
48c5ccae | 4780 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 4781 | { |
70b97a7f | 4782 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
4783 | struct task_struct *next, *stop = rq->stop; |
4784 | int dest_cpu; | |
1da177e4 LT |
4785 | |
4786 | /* | |
48c5ccae PZ |
4787 | * Fudge the rq selection such that the below task selection loop |
4788 | * doesn't get stuck on the currently eligible stop task. | |
4789 | * | |
4790 | * We're currently inside stop_machine() and the rq is either stuck | |
4791 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
4792 | * either way we should never end up calling schedule() until we're | |
4793 | * done here. | |
1da177e4 | 4794 | */ |
48c5ccae | 4795 | rq->stop = NULL; |
48f24c4d | 4796 | |
dd41f596 | 4797 | for ( ; ; ) { |
48c5ccae PZ |
4798 | /* |
4799 | * There's this thread running, bail when that's the only | |
4800 | * remaining thread. | |
4801 | */ | |
4802 | if (rq->nr_running == 1) | |
dd41f596 | 4803 | break; |
48c5ccae | 4804 | |
b67802ea | 4805 | next = pick_next_task(rq); |
48c5ccae | 4806 | BUG_ON(!next); |
79c53799 | 4807 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 4808 | |
48c5ccae PZ |
4809 | /* Find suitable destination for @next, with force if needed. */ |
4810 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
4811 | raw_spin_unlock(&rq->lock); | |
4812 | ||
4813 | __migrate_task(next, dead_cpu, dest_cpu); | |
4814 | ||
4815 | raw_spin_lock(&rq->lock); | |
1da177e4 | 4816 | } |
dce48a84 | 4817 | |
48c5ccae | 4818 | rq->stop = stop; |
dce48a84 | 4819 | } |
48c5ccae | 4820 | |
1da177e4 LT |
4821 | #endif /* CONFIG_HOTPLUG_CPU */ |
4822 | ||
e692ab53 NP |
4823 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
4824 | ||
4825 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
4826 | { |
4827 | .procname = "sched_domain", | |
c57baf1e | 4828 | .mode = 0555, |
e0361851 | 4829 | }, |
56992309 | 4830 | {} |
e692ab53 NP |
4831 | }; |
4832 | ||
4833 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
4834 | { |
4835 | .procname = "kernel", | |
c57baf1e | 4836 | .mode = 0555, |
e0361851 AD |
4837 | .child = sd_ctl_dir, |
4838 | }, | |
56992309 | 4839 | {} |
e692ab53 NP |
4840 | }; |
4841 | ||
4842 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
4843 | { | |
4844 | struct ctl_table *entry = | |
5cf9f062 | 4845 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 4846 | |
e692ab53 NP |
4847 | return entry; |
4848 | } | |
4849 | ||
6382bc90 MM |
4850 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
4851 | { | |
cd790076 | 4852 | struct ctl_table *entry; |
6382bc90 | 4853 | |
cd790076 MM |
4854 | /* |
4855 | * In the intermediate directories, both the child directory and | |
4856 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 4857 | * will always be set. In the lowest directory the names are |
cd790076 MM |
4858 | * static strings and all have proc handlers. |
4859 | */ | |
4860 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
4861 | if (entry->child) |
4862 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
4863 | if (entry->proc_handler == NULL) |
4864 | kfree(entry->procname); | |
4865 | } | |
6382bc90 MM |
4866 | |
4867 | kfree(*tablep); | |
4868 | *tablep = NULL; | |
4869 | } | |
4870 | ||
201c373e NK |
4871 | static int min_load_idx = 0; |
4872 | static int max_load_idx = CPU_LOAD_IDX_MAX; | |
4873 | ||
e692ab53 | 4874 | static void |
e0361851 | 4875 | set_table_entry(struct ctl_table *entry, |
e692ab53 | 4876 | const char *procname, void *data, int maxlen, |
201c373e NK |
4877 | umode_t mode, proc_handler *proc_handler, |
4878 | bool load_idx) | |
e692ab53 | 4879 | { |
e692ab53 NP |
4880 | entry->procname = procname; |
4881 | entry->data = data; | |
4882 | entry->maxlen = maxlen; | |
4883 | entry->mode = mode; | |
4884 | entry->proc_handler = proc_handler; | |
201c373e NK |
4885 | |
4886 | if (load_idx) { | |
4887 | entry->extra1 = &min_load_idx; | |
4888 | entry->extra2 = &max_load_idx; | |
4889 | } | |
e692ab53 NP |
4890 | } |
4891 | ||
4892 | static struct ctl_table * | |
4893 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
4894 | { | |
a5d8c348 | 4895 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 4896 | |
ad1cdc1d MM |
4897 | if (table == NULL) |
4898 | return NULL; | |
4899 | ||
e0361851 | 4900 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
201c373e | 4901 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 4902 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
201c373e | 4903 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 4904 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
201c373e | 4905 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4906 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
201c373e | 4907 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4908 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
201c373e | 4909 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4910 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
201c373e | 4911 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4912 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
201c373e | 4913 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4914 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
201c373e | 4915 | sizeof(int), 0644, proc_dointvec_minmax, false); |
e0361851 | 4916 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
201c373e | 4917 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 4918 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 | 4919 | &sd->cache_nice_tries, |
201c373e | 4920 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 4921 | set_table_entry(&table[10], "flags", &sd->flags, |
201c373e | 4922 | sizeof(int), 0644, proc_dointvec_minmax, false); |
a5d8c348 | 4923 | set_table_entry(&table[11], "name", sd->name, |
201c373e | 4924 | CORENAME_MAX_SIZE, 0444, proc_dostring, false); |
a5d8c348 | 4925 | /* &table[12] is terminator */ |
e692ab53 NP |
4926 | |
4927 | return table; | |
4928 | } | |
4929 | ||
9a4e7159 | 4930 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
4931 | { |
4932 | struct ctl_table *entry, *table; | |
4933 | struct sched_domain *sd; | |
4934 | int domain_num = 0, i; | |
4935 | char buf[32]; | |
4936 | ||
4937 | for_each_domain(cpu, sd) | |
4938 | domain_num++; | |
4939 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
4940 | if (table == NULL) |
4941 | return NULL; | |
e692ab53 NP |
4942 | |
4943 | i = 0; | |
4944 | for_each_domain(cpu, sd) { | |
4945 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 4946 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 4947 | entry->mode = 0555; |
e692ab53 NP |
4948 | entry->child = sd_alloc_ctl_domain_table(sd); |
4949 | entry++; | |
4950 | i++; | |
4951 | } | |
4952 | return table; | |
4953 | } | |
4954 | ||
4955 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 4956 | static void register_sched_domain_sysctl(void) |
e692ab53 | 4957 | { |
6ad4c188 | 4958 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
4959 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
4960 | char buf[32]; | |
4961 | ||
7378547f MM |
4962 | WARN_ON(sd_ctl_dir[0].child); |
4963 | sd_ctl_dir[0].child = entry; | |
4964 | ||
ad1cdc1d MM |
4965 | if (entry == NULL) |
4966 | return; | |
4967 | ||
6ad4c188 | 4968 | for_each_possible_cpu(i) { |
e692ab53 | 4969 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 4970 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 4971 | entry->mode = 0555; |
e692ab53 | 4972 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 4973 | entry++; |
e692ab53 | 4974 | } |
7378547f MM |
4975 | |
4976 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
4977 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
4978 | } | |
6382bc90 | 4979 | |
7378547f | 4980 | /* may be called multiple times per register */ |
6382bc90 MM |
4981 | static void unregister_sched_domain_sysctl(void) |
4982 | { | |
7378547f MM |
4983 | if (sd_sysctl_header) |
4984 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 4985 | sd_sysctl_header = NULL; |
7378547f MM |
4986 | if (sd_ctl_dir[0].child) |
4987 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 4988 | } |
e692ab53 | 4989 | #else |
6382bc90 MM |
4990 | static void register_sched_domain_sysctl(void) |
4991 | { | |
4992 | } | |
4993 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
4994 | { |
4995 | } | |
4996 | #endif | |
4997 | ||
1f11eb6a GH |
4998 | static void set_rq_online(struct rq *rq) |
4999 | { | |
5000 | if (!rq->online) { | |
5001 | const struct sched_class *class; | |
5002 | ||
c6c4927b | 5003 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5004 | rq->online = 1; |
5005 | ||
5006 | for_each_class(class) { | |
5007 | if (class->rq_online) | |
5008 | class->rq_online(rq); | |
5009 | } | |
5010 | } | |
5011 | } | |
5012 | ||
5013 | static void set_rq_offline(struct rq *rq) | |
5014 | { | |
5015 | if (rq->online) { | |
5016 | const struct sched_class *class; | |
5017 | ||
5018 | for_each_class(class) { | |
5019 | if (class->rq_offline) | |
5020 | class->rq_offline(rq); | |
5021 | } | |
5022 | ||
c6c4927b | 5023 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5024 | rq->online = 0; |
5025 | } | |
5026 | } | |
5027 | ||
1da177e4 LT |
5028 | /* |
5029 | * migration_call - callback that gets triggered when a CPU is added. | |
5030 | * Here we can start up the necessary migration thread for the new CPU. | |
5031 | */ | |
48f24c4d IM |
5032 | static int __cpuinit |
5033 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 5034 | { |
48f24c4d | 5035 | int cpu = (long)hcpu; |
1da177e4 | 5036 | unsigned long flags; |
969c7921 | 5037 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 5038 | |
48c5ccae | 5039 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 5040 | |
1da177e4 | 5041 | case CPU_UP_PREPARE: |
a468d389 | 5042 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5043 | break; |
48f24c4d | 5044 | |
1da177e4 | 5045 | case CPU_ONLINE: |
1f94ef59 | 5046 | /* Update our root-domain */ |
05fa785c | 5047 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5048 | if (rq->rd) { |
c6c4927b | 5049 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5050 | |
5051 | set_rq_online(rq); | |
1f94ef59 | 5052 | } |
05fa785c | 5053 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5054 | break; |
48f24c4d | 5055 | |
1da177e4 | 5056 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 5057 | case CPU_DYING: |
317f3941 | 5058 | sched_ttwu_pending(); |
57d885fe | 5059 | /* Update our root-domain */ |
05fa785c | 5060 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5061 | if (rq->rd) { |
c6c4927b | 5062 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5063 | set_rq_offline(rq); |
57d885fe | 5064 | } |
48c5ccae PZ |
5065 | migrate_tasks(cpu); |
5066 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 5067 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
5d180232 | 5068 | break; |
48c5ccae | 5069 | |
5d180232 | 5070 | case CPU_DEAD: |
f319da0c | 5071 | calc_load_migrate(rq); |
57d885fe | 5072 | break; |
1da177e4 LT |
5073 | #endif |
5074 | } | |
49c022e6 PZ |
5075 | |
5076 | update_max_interval(); | |
5077 | ||
1da177e4 LT |
5078 | return NOTIFY_OK; |
5079 | } | |
5080 | ||
f38b0820 PM |
5081 | /* |
5082 | * Register at high priority so that task migration (migrate_all_tasks) | |
5083 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5084 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5085 | */ |
26c2143b | 5086 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 | 5087 | .notifier_call = migration_call, |
50a323b7 | 5088 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
5089 | }; |
5090 | ||
3a101d05 TH |
5091 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, |
5092 | unsigned long action, void *hcpu) | |
5093 | { | |
5094 | switch (action & ~CPU_TASKS_FROZEN) { | |
5fbd036b | 5095 | case CPU_STARTING: |
3a101d05 TH |
5096 | case CPU_DOWN_FAILED: |
5097 | set_cpu_active((long)hcpu, true); | |
5098 | return NOTIFY_OK; | |
5099 | default: | |
5100 | return NOTIFY_DONE; | |
5101 | } | |
5102 | } | |
5103 | ||
5104 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | |
5105 | unsigned long action, void *hcpu) | |
5106 | { | |
5107 | switch (action & ~CPU_TASKS_FROZEN) { | |
5108 | case CPU_DOWN_PREPARE: | |
5109 | set_cpu_active((long)hcpu, false); | |
5110 | return NOTIFY_OK; | |
5111 | default: | |
5112 | return NOTIFY_DONE; | |
5113 | } | |
5114 | } | |
5115 | ||
7babe8db | 5116 | static int __init migration_init(void) |
1da177e4 LT |
5117 | { |
5118 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5119 | int err; |
48f24c4d | 5120 | |
3a101d05 | 5121 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
5122 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5123 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5124 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5125 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5126 | |
3a101d05 TH |
5127 | /* Register cpu active notifiers */ |
5128 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
5129 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
5130 | ||
a004cd42 | 5131 | return 0; |
1da177e4 | 5132 | } |
7babe8db | 5133 | early_initcall(migration_init); |
1da177e4 LT |
5134 | #endif |
5135 | ||
5136 | #ifdef CONFIG_SMP | |
476f3534 | 5137 | |
4cb98839 PZ |
5138 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
5139 | ||
3e9830dc | 5140 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5141 | |
d039ac60 | 5142 | static __read_mostly int sched_debug_enabled; |
f6630114 | 5143 | |
d039ac60 | 5144 | static int __init sched_debug_setup(char *str) |
f6630114 | 5145 | { |
d039ac60 | 5146 | sched_debug_enabled = 1; |
f6630114 MT |
5147 | |
5148 | return 0; | |
5149 | } | |
d039ac60 PZ |
5150 | early_param("sched_debug", sched_debug_setup); |
5151 | ||
5152 | static inline bool sched_debug(void) | |
5153 | { | |
5154 | return sched_debug_enabled; | |
5155 | } | |
f6630114 | 5156 | |
7c16ec58 | 5157 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5158 | struct cpumask *groupmask) |
1da177e4 | 5159 | { |
4dcf6aff | 5160 | struct sched_group *group = sd->groups; |
434d53b0 | 5161 | char str[256]; |
1da177e4 | 5162 | |
968ea6d8 | 5163 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5164 | cpumask_clear(groupmask); |
4dcf6aff IM |
5165 | |
5166 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5167 | ||
5168 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5169 | printk("does not load-balance\n"); |
4dcf6aff | 5170 | if (sd->parent) |
3df0fc5b PZ |
5171 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5172 | " has parent"); | |
4dcf6aff | 5173 | return -1; |
41c7ce9a NP |
5174 | } |
5175 | ||
3df0fc5b | 5176 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5177 | |
758b2cdc | 5178 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5179 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5180 | "CPU%d\n", cpu); | |
4dcf6aff | 5181 | } |
758b2cdc | 5182 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5183 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5184 | " CPU%d\n", cpu); | |
4dcf6aff | 5185 | } |
1da177e4 | 5186 | |
4dcf6aff | 5187 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5188 | do { |
4dcf6aff | 5189 | if (!group) { |
3df0fc5b PZ |
5190 | printk("\n"); |
5191 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5192 | break; |
5193 | } | |
5194 | ||
c3decf0d PZ |
5195 | /* |
5196 | * Even though we initialize ->power to something semi-sane, | |
5197 | * we leave power_orig unset. This allows us to detect if | |
5198 | * domain iteration is still funny without causing /0 traps. | |
5199 | */ | |
5200 | if (!group->sgp->power_orig) { | |
3df0fc5b PZ |
5201 | printk(KERN_CONT "\n"); |
5202 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
5203 | "set\n"); | |
4dcf6aff IM |
5204 | break; |
5205 | } | |
1da177e4 | 5206 | |
758b2cdc | 5207 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5208 | printk(KERN_CONT "\n"); |
5209 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5210 | break; |
5211 | } | |
1da177e4 | 5212 | |
cb83b629 PZ |
5213 | if (!(sd->flags & SD_OVERLAP) && |
5214 | cpumask_intersects(groupmask, sched_group_cpus(group))) { | |
3df0fc5b PZ |
5215 | printk(KERN_CONT "\n"); |
5216 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5217 | break; |
5218 | } | |
1da177e4 | 5219 | |
758b2cdc | 5220 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5221 | |
968ea6d8 | 5222 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5223 | |
3df0fc5b | 5224 | printk(KERN_CONT " %s", str); |
9c3f75cb | 5225 | if (group->sgp->power != SCHED_POWER_SCALE) { |
3df0fc5b | 5226 | printk(KERN_CONT " (cpu_power = %d)", |
9c3f75cb | 5227 | group->sgp->power); |
381512cf | 5228 | } |
1da177e4 | 5229 | |
4dcf6aff IM |
5230 | group = group->next; |
5231 | } while (group != sd->groups); | |
3df0fc5b | 5232 | printk(KERN_CONT "\n"); |
1da177e4 | 5233 | |
758b2cdc | 5234 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 5235 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 5236 | |
758b2cdc RR |
5237 | if (sd->parent && |
5238 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
5239 | printk(KERN_ERR "ERROR: parent span is not a superset " |
5240 | "of domain->span\n"); | |
4dcf6aff IM |
5241 | return 0; |
5242 | } | |
1da177e4 | 5243 | |
4dcf6aff IM |
5244 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
5245 | { | |
5246 | int level = 0; | |
1da177e4 | 5247 | |
d039ac60 | 5248 | if (!sched_debug_enabled) |
f6630114 MT |
5249 | return; |
5250 | ||
4dcf6aff IM |
5251 | if (!sd) { |
5252 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
5253 | return; | |
5254 | } | |
1da177e4 | 5255 | |
4dcf6aff IM |
5256 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
5257 | ||
5258 | for (;;) { | |
4cb98839 | 5259 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 5260 | break; |
1da177e4 LT |
5261 | level++; |
5262 | sd = sd->parent; | |
33859f7f | 5263 | if (!sd) |
4dcf6aff IM |
5264 | break; |
5265 | } | |
1da177e4 | 5266 | } |
6d6bc0ad | 5267 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 5268 | # define sched_domain_debug(sd, cpu) do { } while (0) |
d039ac60 PZ |
5269 | static inline bool sched_debug(void) |
5270 | { | |
5271 | return false; | |
5272 | } | |
6d6bc0ad | 5273 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 5274 | |
1a20ff27 | 5275 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 5276 | { |
758b2cdc | 5277 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
5278 | return 1; |
5279 | ||
5280 | /* Following flags need at least 2 groups */ | |
5281 | if (sd->flags & (SD_LOAD_BALANCE | | |
5282 | SD_BALANCE_NEWIDLE | | |
5283 | SD_BALANCE_FORK | | |
89c4710e SS |
5284 | SD_BALANCE_EXEC | |
5285 | SD_SHARE_CPUPOWER | | |
5286 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
5287 | if (sd->groups != sd->groups->next) |
5288 | return 0; | |
5289 | } | |
5290 | ||
5291 | /* Following flags don't use groups */ | |
c88d5910 | 5292 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
5293 | return 0; |
5294 | ||
5295 | return 1; | |
5296 | } | |
5297 | ||
48f24c4d IM |
5298 | static int |
5299 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
5300 | { |
5301 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
5302 | ||
5303 | if (sd_degenerate(parent)) | |
5304 | return 1; | |
5305 | ||
758b2cdc | 5306 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
5307 | return 0; |
5308 | ||
245af2c7 SS |
5309 | /* Flags needing groups don't count if only 1 group in parent */ |
5310 | if (parent->groups == parent->groups->next) { | |
5311 | pflags &= ~(SD_LOAD_BALANCE | | |
5312 | SD_BALANCE_NEWIDLE | | |
5313 | SD_BALANCE_FORK | | |
89c4710e SS |
5314 | SD_BALANCE_EXEC | |
5315 | SD_SHARE_CPUPOWER | | |
5316 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
5317 | if (nr_node_ids == 1) |
5318 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
5319 | } |
5320 | if (~cflags & pflags) | |
5321 | return 0; | |
5322 | ||
5323 | return 1; | |
5324 | } | |
5325 | ||
dce840a0 | 5326 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 5327 | { |
dce840a0 | 5328 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 5329 | |
68e74568 | 5330 | cpupri_cleanup(&rd->cpupri); |
c6c4927b RR |
5331 | free_cpumask_var(rd->rto_mask); |
5332 | free_cpumask_var(rd->online); | |
5333 | free_cpumask_var(rd->span); | |
5334 | kfree(rd); | |
5335 | } | |
5336 | ||
57d885fe GH |
5337 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
5338 | { | |
a0490fa3 | 5339 | struct root_domain *old_rd = NULL; |
57d885fe | 5340 | unsigned long flags; |
57d885fe | 5341 | |
05fa785c | 5342 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
5343 | |
5344 | if (rq->rd) { | |
a0490fa3 | 5345 | old_rd = rq->rd; |
57d885fe | 5346 | |
c6c4927b | 5347 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 5348 | set_rq_offline(rq); |
57d885fe | 5349 | |
c6c4927b | 5350 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 5351 | |
a0490fa3 IM |
5352 | /* |
5353 | * If we dont want to free the old_rt yet then | |
5354 | * set old_rd to NULL to skip the freeing later | |
5355 | * in this function: | |
5356 | */ | |
5357 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
5358 | old_rd = NULL; | |
57d885fe GH |
5359 | } |
5360 | ||
5361 | atomic_inc(&rd->refcount); | |
5362 | rq->rd = rd; | |
5363 | ||
c6c4927b | 5364 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 5365 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 5366 | set_rq_online(rq); |
57d885fe | 5367 | |
05fa785c | 5368 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
5369 | |
5370 | if (old_rd) | |
dce840a0 | 5371 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
5372 | } |
5373 | ||
68c38fc3 | 5374 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
5375 | { |
5376 | memset(rd, 0, sizeof(*rd)); | |
5377 | ||
68c38fc3 | 5378 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 5379 | goto out; |
68c38fc3 | 5380 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 5381 | goto free_span; |
68c38fc3 | 5382 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
c6c4927b | 5383 | goto free_online; |
6e0534f2 | 5384 | |
68c38fc3 | 5385 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 5386 | goto free_rto_mask; |
c6c4927b | 5387 | return 0; |
6e0534f2 | 5388 | |
68e74568 RR |
5389 | free_rto_mask: |
5390 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
5391 | free_online: |
5392 | free_cpumask_var(rd->online); | |
5393 | free_span: | |
5394 | free_cpumask_var(rd->span); | |
0c910d28 | 5395 | out: |
c6c4927b | 5396 | return -ENOMEM; |
57d885fe GH |
5397 | } |
5398 | ||
029632fb PZ |
5399 | /* |
5400 | * By default the system creates a single root-domain with all cpus as | |
5401 | * members (mimicking the global state we have today). | |
5402 | */ | |
5403 | struct root_domain def_root_domain; | |
5404 | ||
57d885fe GH |
5405 | static void init_defrootdomain(void) |
5406 | { | |
68c38fc3 | 5407 | init_rootdomain(&def_root_domain); |
c6c4927b | 5408 | |
57d885fe GH |
5409 | atomic_set(&def_root_domain.refcount, 1); |
5410 | } | |
5411 | ||
dc938520 | 5412 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
5413 | { |
5414 | struct root_domain *rd; | |
5415 | ||
5416 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
5417 | if (!rd) | |
5418 | return NULL; | |
5419 | ||
68c38fc3 | 5420 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
5421 | kfree(rd); |
5422 | return NULL; | |
5423 | } | |
57d885fe GH |
5424 | |
5425 | return rd; | |
5426 | } | |
5427 | ||
e3589f6c PZ |
5428 | static void free_sched_groups(struct sched_group *sg, int free_sgp) |
5429 | { | |
5430 | struct sched_group *tmp, *first; | |
5431 | ||
5432 | if (!sg) | |
5433 | return; | |
5434 | ||
5435 | first = sg; | |
5436 | do { | |
5437 | tmp = sg->next; | |
5438 | ||
5439 | if (free_sgp && atomic_dec_and_test(&sg->sgp->ref)) | |
5440 | kfree(sg->sgp); | |
5441 | ||
5442 | kfree(sg); | |
5443 | sg = tmp; | |
5444 | } while (sg != first); | |
5445 | } | |
5446 | ||
dce840a0 PZ |
5447 | static void free_sched_domain(struct rcu_head *rcu) |
5448 | { | |
5449 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
5450 | |
5451 | /* | |
5452 | * If its an overlapping domain it has private groups, iterate and | |
5453 | * nuke them all. | |
5454 | */ | |
5455 | if (sd->flags & SD_OVERLAP) { | |
5456 | free_sched_groups(sd->groups, 1); | |
5457 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
9c3f75cb | 5458 | kfree(sd->groups->sgp); |
dce840a0 | 5459 | kfree(sd->groups); |
9c3f75cb | 5460 | } |
dce840a0 PZ |
5461 | kfree(sd); |
5462 | } | |
5463 | ||
5464 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
5465 | { | |
5466 | call_rcu(&sd->rcu, free_sched_domain); | |
5467 | } | |
5468 | ||
5469 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
5470 | { | |
5471 | for (; sd; sd = sd->parent) | |
5472 | destroy_sched_domain(sd, cpu); | |
5473 | } | |
5474 | ||
518cd623 PZ |
5475 | /* |
5476 | * Keep a special pointer to the highest sched_domain that has | |
5477 | * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this | |
5478 | * allows us to avoid some pointer chasing select_idle_sibling(). | |
5479 | * | |
5480 | * Also keep a unique ID per domain (we use the first cpu number in | |
5481 | * the cpumask of the domain), this allows us to quickly tell if | |
39be3501 | 5482 | * two cpus are in the same cache domain, see cpus_share_cache(). |
518cd623 PZ |
5483 | */ |
5484 | DEFINE_PER_CPU(struct sched_domain *, sd_llc); | |
5485 | DEFINE_PER_CPU(int, sd_llc_id); | |
5486 | ||
5487 | static void update_top_cache_domain(int cpu) | |
5488 | { | |
5489 | struct sched_domain *sd; | |
5490 | int id = cpu; | |
5491 | ||
5492 | sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); | |
37407ea7 | 5493 | if (sd) |
518cd623 PZ |
5494 | id = cpumask_first(sched_domain_span(sd)); |
5495 | ||
5496 | rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); | |
5497 | per_cpu(sd_llc_id, cpu) = id; | |
5498 | } | |
5499 | ||
1da177e4 | 5500 | /* |
0eab9146 | 5501 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
5502 | * hold the hotplug lock. |
5503 | */ | |
0eab9146 IM |
5504 | static void |
5505 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 5506 | { |
70b97a7f | 5507 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
5508 | struct sched_domain *tmp; |
5509 | ||
5510 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 5511 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
5512 | struct sched_domain *parent = tmp->parent; |
5513 | if (!parent) | |
5514 | break; | |
f29c9b1c | 5515 | |
1a848870 | 5516 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 5517 | tmp->parent = parent->parent; |
1a848870 SS |
5518 | if (parent->parent) |
5519 | parent->parent->child = tmp; | |
dce840a0 | 5520 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
5521 | } else |
5522 | tmp = tmp->parent; | |
245af2c7 SS |
5523 | } |
5524 | ||
1a848870 | 5525 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 5526 | tmp = sd; |
245af2c7 | 5527 | sd = sd->parent; |
dce840a0 | 5528 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
5529 | if (sd) |
5530 | sd->child = NULL; | |
5531 | } | |
1da177e4 | 5532 | |
4cb98839 | 5533 | sched_domain_debug(sd, cpu); |
1da177e4 | 5534 | |
57d885fe | 5535 | rq_attach_root(rq, rd); |
dce840a0 | 5536 | tmp = rq->sd; |
674311d5 | 5537 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 5538 | destroy_sched_domains(tmp, cpu); |
518cd623 PZ |
5539 | |
5540 | update_top_cache_domain(cpu); | |
1da177e4 LT |
5541 | } |
5542 | ||
5543 | /* cpus with isolated domains */ | |
dcc30a35 | 5544 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
5545 | |
5546 | /* Setup the mask of cpus configured for isolated domains */ | |
5547 | static int __init isolated_cpu_setup(char *str) | |
5548 | { | |
bdddd296 | 5549 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 5550 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
5551 | return 1; |
5552 | } | |
5553 | ||
8927f494 | 5554 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 5555 | |
d3081f52 PZ |
5556 | static const struct cpumask *cpu_cpu_mask(int cpu) |
5557 | { | |
5558 | return cpumask_of_node(cpu_to_node(cpu)); | |
5559 | } | |
5560 | ||
dce840a0 PZ |
5561 | struct sd_data { |
5562 | struct sched_domain **__percpu sd; | |
5563 | struct sched_group **__percpu sg; | |
9c3f75cb | 5564 | struct sched_group_power **__percpu sgp; |
dce840a0 PZ |
5565 | }; |
5566 | ||
49a02c51 | 5567 | struct s_data { |
21d42ccf | 5568 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
5569 | struct root_domain *rd; |
5570 | }; | |
5571 | ||
2109b99e | 5572 | enum s_alloc { |
2109b99e | 5573 | sa_rootdomain, |
21d42ccf | 5574 | sa_sd, |
dce840a0 | 5575 | sa_sd_storage, |
2109b99e AH |
5576 | sa_none, |
5577 | }; | |
5578 | ||
54ab4ff4 PZ |
5579 | struct sched_domain_topology_level; |
5580 | ||
5581 | typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu); | |
eb7a74e6 PZ |
5582 | typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); |
5583 | ||
e3589f6c PZ |
5584 | #define SDTL_OVERLAP 0x01 |
5585 | ||
eb7a74e6 | 5586 | struct sched_domain_topology_level { |
2c402dc3 PZ |
5587 | sched_domain_init_f init; |
5588 | sched_domain_mask_f mask; | |
e3589f6c | 5589 | int flags; |
cb83b629 | 5590 | int numa_level; |
54ab4ff4 | 5591 | struct sd_data data; |
eb7a74e6 PZ |
5592 | }; |
5593 | ||
c1174876 PZ |
5594 | /* |
5595 | * Build an iteration mask that can exclude certain CPUs from the upwards | |
5596 | * domain traversal. | |
5597 | * | |
5598 | * Asymmetric node setups can result in situations where the domain tree is of | |
5599 | * unequal depth, make sure to skip domains that already cover the entire | |
5600 | * range. | |
5601 | * | |
5602 | * In that case build_sched_domains() will have terminated the iteration early | |
5603 | * and our sibling sd spans will be empty. Domains should always include the | |
5604 | * cpu they're built on, so check that. | |
5605 | * | |
5606 | */ | |
5607 | static void build_group_mask(struct sched_domain *sd, struct sched_group *sg) | |
5608 | { | |
5609 | const struct cpumask *span = sched_domain_span(sd); | |
5610 | struct sd_data *sdd = sd->private; | |
5611 | struct sched_domain *sibling; | |
5612 | int i; | |
5613 | ||
5614 | for_each_cpu(i, span) { | |
5615 | sibling = *per_cpu_ptr(sdd->sd, i); | |
5616 | if (!cpumask_test_cpu(i, sched_domain_span(sibling))) | |
5617 | continue; | |
5618 | ||
5619 | cpumask_set_cpu(i, sched_group_mask(sg)); | |
5620 | } | |
5621 | } | |
5622 | ||
5623 | /* | |
5624 | * Return the canonical balance cpu for this group, this is the first cpu | |
5625 | * of this group that's also in the iteration mask. | |
5626 | */ | |
5627 | int group_balance_cpu(struct sched_group *sg) | |
5628 | { | |
5629 | return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg)); | |
5630 | } | |
5631 | ||
e3589f6c PZ |
5632 | static int |
5633 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
5634 | { | |
5635 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
5636 | const struct cpumask *span = sched_domain_span(sd); | |
5637 | struct cpumask *covered = sched_domains_tmpmask; | |
5638 | struct sd_data *sdd = sd->private; | |
5639 | struct sched_domain *child; | |
5640 | int i; | |
5641 | ||
5642 | cpumask_clear(covered); | |
5643 | ||
5644 | for_each_cpu(i, span) { | |
5645 | struct cpumask *sg_span; | |
5646 | ||
5647 | if (cpumask_test_cpu(i, covered)) | |
5648 | continue; | |
5649 | ||
c1174876 PZ |
5650 | child = *per_cpu_ptr(sdd->sd, i); |
5651 | ||
5652 | /* See the comment near build_group_mask(). */ | |
5653 | if (!cpumask_test_cpu(i, sched_domain_span(child))) | |
5654 | continue; | |
5655 | ||
e3589f6c | 5656 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), |
4d78a223 | 5657 | GFP_KERNEL, cpu_to_node(cpu)); |
e3589f6c PZ |
5658 | |
5659 | if (!sg) | |
5660 | goto fail; | |
5661 | ||
5662 | sg_span = sched_group_cpus(sg); | |
e3589f6c PZ |
5663 | if (child->child) { |
5664 | child = child->child; | |
5665 | cpumask_copy(sg_span, sched_domain_span(child)); | |
5666 | } else | |
5667 | cpumask_set_cpu(i, sg_span); | |
5668 | ||
5669 | cpumask_or(covered, covered, sg_span); | |
5670 | ||
74a5ce20 | 5671 | sg->sgp = *per_cpu_ptr(sdd->sgp, i); |
c1174876 PZ |
5672 | if (atomic_inc_return(&sg->sgp->ref) == 1) |
5673 | build_group_mask(sd, sg); | |
5674 | ||
c3decf0d PZ |
5675 | /* |
5676 | * Initialize sgp->power such that even if we mess up the | |
5677 | * domains and no possible iteration will get us here, we won't | |
5678 | * die on a /0 trap. | |
5679 | */ | |
5680 | sg->sgp->power = SCHED_POWER_SCALE * cpumask_weight(sg_span); | |
e3589f6c | 5681 | |
c1174876 PZ |
5682 | /* |
5683 | * Make sure the first group of this domain contains the | |
5684 | * canonical balance cpu. Otherwise the sched_domain iteration | |
5685 | * breaks. See update_sg_lb_stats(). | |
5686 | */ | |
74a5ce20 | 5687 | if ((!groups && cpumask_test_cpu(cpu, sg_span)) || |
c1174876 | 5688 | group_balance_cpu(sg) == cpu) |
e3589f6c PZ |
5689 | groups = sg; |
5690 | ||
5691 | if (!first) | |
5692 | first = sg; | |
5693 | if (last) | |
5694 | last->next = sg; | |
5695 | last = sg; | |
5696 | last->next = first; | |
5697 | } | |
5698 | sd->groups = groups; | |
5699 | ||
5700 | return 0; | |
5701 | ||
5702 | fail: | |
5703 | free_sched_groups(first, 0); | |
5704 | ||
5705 | return -ENOMEM; | |
5706 | } | |
5707 | ||
dce840a0 | 5708 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 5709 | { |
dce840a0 PZ |
5710 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
5711 | struct sched_domain *child = sd->child; | |
1da177e4 | 5712 | |
dce840a0 PZ |
5713 | if (child) |
5714 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 5715 | |
9c3f75cb | 5716 | if (sg) { |
dce840a0 | 5717 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
9c3f75cb | 5718 | (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu); |
e3589f6c | 5719 | atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */ |
9c3f75cb | 5720 | } |
dce840a0 PZ |
5721 | |
5722 | return cpu; | |
1e9f28fa | 5723 | } |
1e9f28fa | 5724 | |
01a08546 | 5725 | /* |
dce840a0 PZ |
5726 | * build_sched_groups will build a circular linked list of the groups |
5727 | * covered by the given span, and will set each group's ->cpumask correctly, | |
5728 | * and ->cpu_power to 0. | |
e3589f6c PZ |
5729 | * |
5730 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 5731 | */ |
e3589f6c PZ |
5732 | static int |
5733 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 5734 | { |
dce840a0 PZ |
5735 | struct sched_group *first = NULL, *last = NULL; |
5736 | struct sd_data *sdd = sd->private; | |
5737 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 5738 | struct cpumask *covered; |
dce840a0 | 5739 | int i; |
9c1cfda2 | 5740 | |
e3589f6c PZ |
5741 | get_group(cpu, sdd, &sd->groups); |
5742 | atomic_inc(&sd->groups->ref); | |
5743 | ||
5744 | if (cpu != cpumask_first(sched_domain_span(sd))) | |
5745 | return 0; | |
5746 | ||
f96225fd PZ |
5747 | lockdep_assert_held(&sched_domains_mutex); |
5748 | covered = sched_domains_tmpmask; | |
5749 | ||
dce840a0 | 5750 | cpumask_clear(covered); |
6711cab4 | 5751 | |
dce840a0 PZ |
5752 | for_each_cpu(i, span) { |
5753 | struct sched_group *sg; | |
5754 | int group = get_group(i, sdd, &sg); | |
5755 | int j; | |
6711cab4 | 5756 | |
dce840a0 PZ |
5757 | if (cpumask_test_cpu(i, covered)) |
5758 | continue; | |
6711cab4 | 5759 | |
dce840a0 | 5760 | cpumask_clear(sched_group_cpus(sg)); |
9c3f75cb | 5761 | sg->sgp->power = 0; |
c1174876 | 5762 | cpumask_setall(sched_group_mask(sg)); |
0601a88d | 5763 | |
dce840a0 PZ |
5764 | for_each_cpu(j, span) { |
5765 | if (get_group(j, sdd, NULL) != group) | |
5766 | continue; | |
0601a88d | 5767 | |
dce840a0 PZ |
5768 | cpumask_set_cpu(j, covered); |
5769 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
5770 | } | |
0601a88d | 5771 | |
dce840a0 PZ |
5772 | if (!first) |
5773 | first = sg; | |
5774 | if (last) | |
5775 | last->next = sg; | |
5776 | last = sg; | |
5777 | } | |
5778 | last->next = first; | |
e3589f6c PZ |
5779 | |
5780 | return 0; | |
0601a88d | 5781 | } |
51888ca2 | 5782 | |
89c4710e SS |
5783 | /* |
5784 | * Initialize sched groups cpu_power. | |
5785 | * | |
5786 | * cpu_power indicates the capacity of sched group, which is used while | |
5787 | * distributing the load between different sched groups in a sched domain. | |
5788 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
5789 | * there are asymmetries in the topology. If there are asymmetries, group | |
5790 | * having more cpu_power will pickup more load compared to the group having | |
5791 | * less cpu_power. | |
89c4710e SS |
5792 | */ |
5793 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
5794 | { | |
e3589f6c | 5795 | struct sched_group *sg = sd->groups; |
89c4710e | 5796 | |
e3589f6c PZ |
5797 | WARN_ON(!sd || !sg); |
5798 | ||
5799 | do { | |
5800 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
5801 | sg = sg->next; | |
5802 | } while (sg != sd->groups); | |
89c4710e | 5803 | |
c1174876 | 5804 | if (cpu != group_balance_cpu(sg)) |
e3589f6c | 5805 | return; |
aae6d3dd | 5806 | |
d274cb30 | 5807 | update_group_power(sd, cpu); |
69e1e811 | 5808 | atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight); |
89c4710e SS |
5809 | } |
5810 | ||
029632fb PZ |
5811 | int __weak arch_sd_sibling_asym_packing(void) |
5812 | { | |
5813 | return 0*SD_ASYM_PACKING; | |
89c4710e SS |
5814 | } |
5815 | ||
7c16ec58 MT |
5816 | /* |
5817 | * Initializers for schedule domains | |
5818 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
5819 | */ | |
5820 | ||
a5d8c348 IM |
5821 | #ifdef CONFIG_SCHED_DEBUG |
5822 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
5823 | #else | |
5824 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
5825 | #endif | |
5826 | ||
54ab4ff4 PZ |
5827 | #define SD_INIT_FUNC(type) \ |
5828 | static noinline struct sched_domain * \ | |
5829 | sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \ | |
5830 | { \ | |
5831 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \ | |
5832 | *sd = SD_##type##_INIT; \ | |
54ab4ff4 PZ |
5833 | SD_INIT_NAME(sd, type); \ |
5834 | sd->private = &tl->data; \ | |
5835 | return sd; \ | |
7c16ec58 MT |
5836 | } |
5837 | ||
5838 | SD_INIT_FUNC(CPU) | |
7c16ec58 MT |
5839 | #ifdef CONFIG_SCHED_SMT |
5840 | SD_INIT_FUNC(SIBLING) | |
5841 | #endif | |
5842 | #ifdef CONFIG_SCHED_MC | |
5843 | SD_INIT_FUNC(MC) | |
5844 | #endif | |
01a08546 HC |
5845 | #ifdef CONFIG_SCHED_BOOK |
5846 | SD_INIT_FUNC(BOOK) | |
5847 | #endif | |
7c16ec58 | 5848 | |
1d3504fc | 5849 | static int default_relax_domain_level = -1; |
60495e77 | 5850 | int sched_domain_level_max; |
1d3504fc HS |
5851 | |
5852 | static int __init setup_relax_domain_level(char *str) | |
5853 | { | |
a841f8ce DS |
5854 | if (kstrtoint(str, 0, &default_relax_domain_level)) |
5855 | pr_warn("Unable to set relax_domain_level\n"); | |
30e0e178 | 5856 | |
1d3504fc HS |
5857 | return 1; |
5858 | } | |
5859 | __setup("relax_domain_level=", setup_relax_domain_level); | |
5860 | ||
5861 | static void set_domain_attribute(struct sched_domain *sd, | |
5862 | struct sched_domain_attr *attr) | |
5863 | { | |
5864 | int request; | |
5865 | ||
5866 | if (!attr || attr->relax_domain_level < 0) { | |
5867 | if (default_relax_domain_level < 0) | |
5868 | return; | |
5869 | else | |
5870 | request = default_relax_domain_level; | |
5871 | } else | |
5872 | request = attr->relax_domain_level; | |
5873 | if (request < sd->level) { | |
5874 | /* turn off idle balance on this domain */ | |
c88d5910 | 5875 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
5876 | } else { |
5877 | /* turn on idle balance on this domain */ | |
c88d5910 | 5878 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
5879 | } |
5880 | } | |
5881 | ||
54ab4ff4 PZ |
5882 | static void __sdt_free(const struct cpumask *cpu_map); |
5883 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
5884 | ||
2109b99e AH |
5885 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
5886 | const struct cpumask *cpu_map) | |
5887 | { | |
5888 | switch (what) { | |
2109b99e | 5889 | case sa_rootdomain: |
822ff793 PZ |
5890 | if (!atomic_read(&d->rd->refcount)) |
5891 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
5892 | case sa_sd: |
5893 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 5894 | case sa_sd_storage: |
54ab4ff4 | 5895 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
5896 | case sa_none: |
5897 | break; | |
5898 | } | |
5899 | } | |
3404c8d9 | 5900 | |
2109b99e AH |
5901 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
5902 | const struct cpumask *cpu_map) | |
5903 | { | |
dce840a0 PZ |
5904 | memset(d, 0, sizeof(*d)); |
5905 | ||
54ab4ff4 PZ |
5906 | if (__sdt_alloc(cpu_map)) |
5907 | return sa_sd_storage; | |
dce840a0 PZ |
5908 | d->sd = alloc_percpu(struct sched_domain *); |
5909 | if (!d->sd) | |
5910 | return sa_sd_storage; | |
2109b99e | 5911 | d->rd = alloc_rootdomain(); |
dce840a0 | 5912 | if (!d->rd) |
21d42ccf | 5913 | return sa_sd; |
2109b99e AH |
5914 | return sa_rootdomain; |
5915 | } | |
57d885fe | 5916 | |
dce840a0 PZ |
5917 | /* |
5918 | * NULL the sd_data elements we've used to build the sched_domain and | |
5919 | * sched_group structure so that the subsequent __free_domain_allocs() | |
5920 | * will not free the data we're using. | |
5921 | */ | |
5922 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
5923 | { | |
5924 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
5925 | |
5926 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
5927 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
5928 | ||
e3589f6c | 5929 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 5930 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c PZ |
5931 | |
5932 | if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref)) | |
9c3f75cb | 5933 | *per_cpu_ptr(sdd->sgp, cpu) = NULL; |
dce840a0 PZ |
5934 | } |
5935 | ||
2c402dc3 PZ |
5936 | #ifdef CONFIG_SCHED_SMT |
5937 | static const struct cpumask *cpu_smt_mask(int cpu) | |
7f4588f3 | 5938 | { |
2c402dc3 | 5939 | return topology_thread_cpumask(cpu); |
3bd65a80 | 5940 | } |
2c402dc3 | 5941 | #endif |
7f4588f3 | 5942 | |
d069b916 PZ |
5943 | /* |
5944 | * Topology list, bottom-up. | |
5945 | */ | |
2c402dc3 | 5946 | static struct sched_domain_topology_level default_topology[] = { |
d069b916 PZ |
5947 | #ifdef CONFIG_SCHED_SMT |
5948 | { sd_init_SIBLING, cpu_smt_mask, }, | |
01a08546 | 5949 | #endif |
1e9f28fa | 5950 | #ifdef CONFIG_SCHED_MC |
2c402dc3 | 5951 | { sd_init_MC, cpu_coregroup_mask, }, |
1e9f28fa | 5952 | #endif |
d069b916 PZ |
5953 | #ifdef CONFIG_SCHED_BOOK |
5954 | { sd_init_BOOK, cpu_book_mask, }, | |
5955 | #endif | |
5956 | { sd_init_CPU, cpu_cpu_mask, }, | |
eb7a74e6 PZ |
5957 | { NULL, }, |
5958 | }; | |
5959 | ||
5960 | static struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
5961 | ||
cb83b629 PZ |
5962 | #ifdef CONFIG_NUMA |
5963 | ||
5964 | static int sched_domains_numa_levels; | |
cb83b629 PZ |
5965 | static int *sched_domains_numa_distance; |
5966 | static struct cpumask ***sched_domains_numa_masks; | |
5967 | static int sched_domains_curr_level; | |
5968 | ||
cb83b629 PZ |
5969 | static inline int sd_local_flags(int level) |
5970 | { | |
10717dcd | 5971 | if (sched_domains_numa_distance[level] > RECLAIM_DISTANCE) |
cb83b629 PZ |
5972 | return 0; |
5973 | ||
5974 | return SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE; | |
5975 | } | |
5976 | ||
5977 | static struct sched_domain * | |
5978 | sd_numa_init(struct sched_domain_topology_level *tl, int cpu) | |
5979 | { | |
5980 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); | |
5981 | int level = tl->numa_level; | |
5982 | int sd_weight = cpumask_weight( | |
5983 | sched_domains_numa_masks[level][cpu_to_node(cpu)]); | |
5984 | ||
5985 | *sd = (struct sched_domain){ | |
5986 | .min_interval = sd_weight, | |
5987 | .max_interval = 2*sd_weight, | |
5988 | .busy_factor = 32, | |
870a0bb5 | 5989 | .imbalance_pct = 125, |
cb83b629 PZ |
5990 | .cache_nice_tries = 2, |
5991 | .busy_idx = 3, | |
5992 | .idle_idx = 2, | |
5993 | .newidle_idx = 0, | |
5994 | .wake_idx = 0, | |
5995 | .forkexec_idx = 0, | |
5996 | ||
5997 | .flags = 1*SD_LOAD_BALANCE | |
5998 | | 1*SD_BALANCE_NEWIDLE | |
5999 | | 0*SD_BALANCE_EXEC | |
6000 | | 0*SD_BALANCE_FORK | |
6001 | | 0*SD_BALANCE_WAKE | |
6002 | | 0*SD_WAKE_AFFINE | |
cb83b629 | 6003 | | 0*SD_SHARE_CPUPOWER |
cb83b629 PZ |
6004 | | 0*SD_SHARE_PKG_RESOURCES |
6005 | | 1*SD_SERIALIZE | |
6006 | | 0*SD_PREFER_SIBLING | |
6007 | | sd_local_flags(level) | |
6008 | , | |
6009 | .last_balance = jiffies, | |
6010 | .balance_interval = sd_weight, | |
6011 | }; | |
6012 | SD_INIT_NAME(sd, NUMA); | |
6013 | sd->private = &tl->data; | |
6014 | ||
6015 | /* | |
6016 | * Ugly hack to pass state to sd_numa_mask()... | |
6017 | */ | |
6018 | sched_domains_curr_level = tl->numa_level; | |
6019 | ||
6020 | return sd; | |
6021 | } | |
6022 | ||
6023 | static const struct cpumask *sd_numa_mask(int cpu) | |
6024 | { | |
6025 | return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; | |
6026 | } | |
6027 | ||
d039ac60 PZ |
6028 | static void sched_numa_warn(const char *str) |
6029 | { | |
6030 | static int done = false; | |
6031 | int i,j; | |
6032 | ||
6033 | if (done) | |
6034 | return; | |
6035 | ||
6036 | done = true; | |
6037 | ||
6038 | printk(KERN_WARNING "ERROR: %s\n\n", str); | |
6039 | ||
6040 | for (i = 0; i < nr_node_ids; i++) { | |
6041 | printk(KERN_WARNING " "); | |
6042 | for (j = 0; j < nr_node_ids; j++) | |
6043 | printk(KERN_CONT "%02d ", node_distance(i,j)); | |
6044 | printk(KERN_CONT "\n"); | |
6045 | } | |
6046 | printk(KERN_WARNING "\n"); | |
6047 | } | |
6048 | ||
6049 | static bool find_numa_distance(int distance) | |
6050 | { | |
6051 | int i; | |
6052 | ||
6053 | if (distance == node_distance(0, 0)) | |
6054 | return true; | |
6055 | ||
6056 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6057 | if (sched_domains_numa_distance[i] == distance) | |
6058 | return true; | |
6059 | } | |
6060 | ||
6061 | return false; | |
6062 | } | |
6063 | ||
cb83b629 PZ |
6064 | static void sched_init_numa(void) |
6065 | { | |
6066 | int next_distance, curr_distance = node_distance(0, 0); | |
6067 | struct sched_domain_topology_level *tl; | |
6068 | int level = 0; | |
6069 | int i, j, k; | |
6070 | ||
cb83b629 PZ |
6071 | sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL); |
6072 | if (!sched_domains_numa_distance) | |
6073 | return; | |
6074 | ||
6075 | /* | |
6076 | * O(nr_nodes^2) deduplicating selection sort -- in order to find the | |
6077 | * unique distances in the node_distance() table. | |
6078 | * | |
6079 | * Assumes node_distance(0,j) includes all distances in | |
6080 | * node_distance(i,j) in order to avoid cubic time. | |
cb83b629 PZ |
6081 | */ |
6082 | next_distance = curr_distance; | |
6083 | for (i = 0; i < nr_node_ids; i++) { | |
6084 | for (j = 0; j < nr_node_ids; j++) { | |
d039ac60 PZ |
6085 | for (k = 0; k < nr_node_ids; k++) { |
6086 | int distance = node_distance(i, k); | |
6087 | ||
6088 | if (distance > curr_distance && | |
6089 | (distance < next_distance || | |
6090 | next_distance == curr_distance)) | |
6091 | next_distance = distance; | |
6092 | ||
6093 | /* | |
6094 | * While not a strong assumption it would be nice to know | |
6095 | * about cases where if node A is connected to B, B is not | |
6096 | * equally connected to A. | |
6097 | */ | |
6098 | if (sched_debug() && node_distance(k, i) != distance) | |
6099 | sched_numa_warn("Node-distance not symmetric"); | |
6100 | ||
6101 | if (sched_debug() && i && !find_numa_distance(distance)) | |
6102 | sched_numa_warn("Node-0 not representative"); | |
6103 | } | |
6104 | if (next_distance != curr_distance) { | |
6105 | sched_domains_numa_distance[level++] = next_distance; | |
6106 | sched_domains_numa_levels = level; | |
6107 | curr_distance = next_distance; | |
6108 | } else break; | |
cb83b629 | 6109 | } |
d039ac60 PZ |
6110 | |
6111 | /* | |
6112 | * In case of sched_debug() we verify the above assumption. | |
6113 | */ | |
6114 | if (!sched_debug()) | |
6115 | break; | |
cb83b629 PZ |
6116 | } |
6117 | /* | |
6118 | * 'level' contains the number of unique distances, excluding the | |
6119 | * identity distance node_distance(i,i). | |
6120 | * | |
6121 | * The sched_domains_nume_distance[] array includes the actual distance | |
6122 | * numbers. | |
6123 | */ | |
6124 | ||
5f7865f3 TC |
6125 | /* |
6126 | * Here, we should temporarily reset sched_domains_numa_levels to 0. | |
6127 | * If it fails to allocate memory for array sched_domains_numa_masks[][], | |
6128 | * the array will contain less then 'level' members. This could be | |
6129 | * dangerous when we use it to iterate array sched_domains_numa_masks[][] | |
6130 | * in other functions. | |
6131 | * | |
6132 | * We reset it to 'level' at the end of this function. | |
6133 | */ | |
6134 | sched_domains_numa_levels = 0; | |
6135 | ||
cb83b629 PZ |
6136 | sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); |
6137 | if (!sched_domains_numa_masks) | |
6138 | return; | |
6139 | ||
6140 | /* | |
6141 | * Now for each level, construct a mask per node which contains all | |
6142 | * cpus of nodes that are that many hops away from us. | |
6143 | */ | |
6144 | for (i = 0; i < level; i++) { | |
6145 | sched_domains_numa_masks[i] = | |
6146 | kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); | |
6147 | if (!sched_domains_numa_masks[i]) | |
6148 | return; | |
6149 | ||
6150 | for (j = 0; j < nr_node_ids; j++) { | |
2ea45800 | 6151 | struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); |
cb83b629 PZ |
6152 | if (!mask) |
6153 | return; | |
6154 | ||
6155 | sched_domains_numa_masks[i][j] = mask; | |
6156 | ||
6157 | for (k = 0; k < nr_node_ids; k++) { | |
dd7d8634 | 6158 | if (node_distance(j, k) > sched_domains_numa_distance[i]) |
cb83b629 PZ |
6159 | continue; |
6160 | ||
6161 | cpumask_or(mask, mask, cpumask_of_node(k)); | |
6162 | } | |
6163 | } | |
6164 | } | |
6165 | ||
6166 | tl = kzalloc((ARRAY_SIZE(default_topology) + level) * | |
6167 | sizeof(struct sched_domain_topology_level), GFP_KERNEL); | |
6168 | if (!tl) | |
6169 | return; | |
6170 | ||
6171 | /* | |
6172 | * Copy the default topology bits.. | |
6173 | */ | |
6174 | for (i = 0; default_topology[i].init; i++) | |
6175 | tl[i] = default_topology[i]; | |
6176 | ||
6177 | /* | |
6178 | * .. and append 'j' levels of NUMA goodness. | |
6179 | */ | |
6180 | for (j = 0; j < level; i++, j++) { | |
6181 | tl[i] = (struct sched_domain_topology_level){ | |
6182 | .init = sd_numa_init, | |
6183 | .mask = sd_numa_mask, | |
6184 | .flags = SDTL_OVERLAP, | |
6185 | .numa_level = j, | |
6186 | }; | |
6187 | } | |
6188 | ||
6189 | sched_domain_topology = tl; | |
5f7865f3 TC |
6190 | |
6191 | sched_domains_numa_levels = level; | |
cb83b629 | 6192 | } |
301a5cba TC |
6193 | |
6194 | static void sched_domains_numa_masks_set(int cpu) | |
6195 | { | |
6196 | int i, j; | |
6197 | int node = cpu_to_node(cpu); | |
6198 | ||
6199 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6200 | for (j = 0; j < nr_node_ids; j++) { | |
6201 | if (node_distance(j, node) <= sched_domains_numa_distance[i]) | |
6202 | cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6203 | } | |
6204 | } | |
6205 | } | |
6206 | ||
6207 | static void sched_domains_numa_masks_clear(int cpu) | |
6208 | { | |
6209 | int i, j; | |
6210 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6211 | for (j = 0; j < nr_node_ids; j++) | |
6212 | cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6213 | } | |
6214 | } | |
6215 | ||
6216 | /* | |
6217 | * Update sched_domains_numa_masks[level][node] array when new cpus | |
6218 | * are onlined. | |
6219 | */ | |
6220 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6221 | unsigned long action, | |
6222 | void *hcpu) | |
6223 | { | |
6224 | int cpu = (long)hcpu; | |
6225 | ||
6226 | switch (action & ~CPU_TASKS_FROZEN) { | |
6227 | case CPU_ONLINE: | |
6228 | sched_domains_numa_masks_set(cpu); | |
6229 | break; | |
6230 | ||
6231 | case CPU_DEAD: | |
6232 | sched_domains_numa_masks_clear(cpu); | |
6233 | break; | |
6234 | ||
6235 | default: | |
6236 | return NOTIFY_DONE; | |
6237 | } | |
6238 | ||
6239 | return NOTIFY_OK; | |
cb83b629 PZ |
6240 | } |
6241 | #else | |
6242 | static inline void sched_init_numa(void) | |
6243 | { | |
6244 | } | |
301a5cba TC |
6245 | |
6246 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6247 | unsigned long action, | |
6248 | void *hcpu) | |
6249 | { | |
6250 | return 0; | |
6251 | } | |
cb83b629 PZ |
6252 | #endif /* CONFIG_NUMA */ |
6253 | ||
54ab4ff4 PZ |
6254 | static int __sdt_alloc(const struct cpumask *cpu_map) |
6255 | { | |
6256 | struct sched_domain_topology_level *tl; | |
6257 | int j; | |
6258 | ||
6259 | for (tl = sched_domain_topology; tl->init; tl++) { | |
6260 | struct sd_data *sdd = &tl->data; | |
6261 | ||
6262 | sdd->sd = alloc_percpu(struct sched_domain *); | |
6263 | if (!sdd->sd) | |
6264 | return -ENOMEM; | |
6265 | ||
6266 | sdd->sg = alloc_percpu(struct sched_group *); | |
6267 | if (!sdd->sg) | |
6268 | return -ENOMEM; | |
6269 | ||
9c3f75cb PZ |
6270 | sdd->sgp = alloc_percpu(struct sched_group_power *); |
6271 | if (!sdd->sgp) | |
6272 | return -ENOMEM; | |
6273 | ||
54ab4ff4 PZ |
6274 | for_each_cpu(j, cpu_map) { |
6275 | struct sched_domain *sd; | |
6276 | struct sched_group *sg; | |
9c3f75cb | 6277 | struct sched_group_power *sgp; |
54ab4ff4 PZ |
6278 | |
6279 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
6280 | GFP_KERNEL, cpu_to_node(j)); | |
6281 | if (!sd) | |
6282 | return -ENOMEM; | |
6283 | ||
6284 | *per_cpu_ptr(sdd->sd, j) = sd; | |
6285 | ||
6286 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6287 | GFP_KERNEL, cpu_to_node(j)); | |
6288 | if (!sg) | |
6289 | return -ENOMEM; | |
6290 | ||
30b4e9eb IM |
6291 | sg->next = sg; |
6292 | ||
54ab4ff4 | 6293 | *per_cpu_ptr(sdd->sg, j) = sg; |
9c3f75cb | 6294 | |
c1174876 | 6295 | sgp = kzalloc_node(sizeof(struct sched_group_power) + cpumask_size(), |
9c3f75cb PZ |
6296 | GFP_KERNEL, cpu_to_node(j)); |
6297 | if (!sgp) | |
6298 | return -ENOMEM; | |
6299 | ||
6300 | *per_cpu_ptr(sdd->sgp, j) = sgp; | |
54ab4ff4 PZ |
6301 | } |
6302 | } | |
6303 | ||
6304 | return 0; | |
6305 | } | |
6306 | ||
6307 | static void __sdt_free(const struct cpumask *cpu_map) | |
6308 | { | |
6309 | struct sched_domain_topology_level *tl; | |
6310 | int j; | |
6311 | ||
6312 | for (tl = sched_domain_topology; tl->init; tl++) { | |
6313 | struct sd_data *sdd = &tl->data; | |
6314 | ||
6315 | for_each_cpu(j, cpu_map) { | |
fb2cf2c6 | 6316 | struct sched_domain *sd; |
6317 | ||
6318 | if (sdd->sd) { | |
6319 | sd = *per_cpu_ptr(sdd->sd, j); | |
6320 | if (sd && (sd->flags & SD_OVERLAP)) | |
6321 | free_sched_groups(sd->groups, 0); | |
6322 | kfree(*per_cpu_ptr(sdd->sd, j)); | |
6323 | } | |
6324 | ||
6325 | if (sdd->sg) | |
6326 | kfree(*per_cpu_ptr(sdd->sg, j)); | |
6327 | if (sdd->sgp) | |
6328 | kfree(*per_cpu_ptr(sdd->sgp, j)); | |
54ab4ff4 PZ |
6329 | } |
6330 | free_percpu(sdd->sd); | |
fb2cf2c6 | 6331 | sdd->sd = NULL; |
54ab4ff4 | 6332 | free_percpu(sdd->sg); |
fb2cf2c6 | 6333 | sdd->sg = NULL; |
9c3f75cb | 6334 | free_percpu(sdd->sgp); |
fb2cf2c6 | 6335 | sdd->sgp = NULL; |
54ab4ff4 PZ |
6336 | } |
6337 | } | |
6338 | ||
2c402dc3 PZ |
6339 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
6340 | struct s_data *d, const struct cpumask *cpu_map, | |
d069b916 | 6341 | struct sched_domain_attr *attr, struct sched_domain *child, |
2c402dc3 PZ |
6342 | int cpu) |
6343 | { | |
54ab4ff4 | 6344 | struct sched_domain *sd = tl->init(tl, cpu); |
2c402dc3 | 6345 | if (!sd) |
d069b916 | 6346 | return child; |
2c402dc3 | 6347 | |
2c402dc3 | 6348 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); |
60495e77 PZ |
6349 | if (child) { |
6350 | sd->level = child->level + 1; | |
6351 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 6352 | child->parent = sd; |
60495e77 | 6353 | } |
d069b916 | 6354 | sd->child = child; |
a841f8ce | 6355 | set_domain_attribute(sd, attr); |
2c402dc3 PZ |
6356 | |
6357 | return sd; | |
6358 | } | |
6359 | ||
2109b99e AH |
6360 | /* |
6361 | * Build sched domains for a given set of cpus and attach the sched domains | |
6362 | * to the individual cpus | |
6363 | */ | |
dce840a0 PZ |
6364 | static int build_sched_domains(const struct cpumask *cpu_map, |
6365 | struct sched_domain_attr *attr) | |
2109b99e AH |
6366 | { |
6367 | enum s_alloc alloc_state = sa_none; | |
dce840a0 | 6368 | struct sched_domain *sd; |
2109b99e | 6369 | struct s_data d; |
822ff793 | 6370 | int i, ret = -ENOMEM; |
9c1cfda2 | 6371 | |
2109b99e AH |
6372 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6373 | if (alloc_state != sa_rootdomain) | |
6374 | goto error; | |
9c1cfda2 | 6375 | |
dce840a0 | 6376 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 6377 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
6378 | struct sched_domain_topology_level *tl; |
6379 | ||
3bd65a80 | 6380 | sd = NULL; |
e3589f6c | 6381 | for (tl = sched_domain_topology; tl->init; tl++) { |
2c402dc3 | 6382 | sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i); |
e3589f6c PZ |
6383 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
6384 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
6385 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
6386 | break; | |
e3589f6c | 6387 | } |
d274cb30 | 6388 | |
d069b916 PZ |
6389 | while (sd->child) |
6390 | sd = sd->child; | |
6391 | ||
21d42ccf | 6392 | *per_cpu_ptr(d.sd, i) = sd; |
dce840a0 PZ |
6393 | } |
6394 | ||
6395 | /* Build the groups for the domains */ | |
6396 | for_each_cpu(i, cpu_map) { | |
6397 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
6398 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
6399 | if (sd->flags & SD_OVERLAP) { |
6400 | if (build_overlap_sched_groups(sd, i)) | |
6401 | goto error; | |
6402 | } else { | |
6403 | if (build_sched_groups(sd, i)) | |
6404 | goto error; | |
6405 | } | |
1cf51902 | 6406 | } |
a06dadbe | 6407 | } |
9c1cfda2 | 6408 | |
1da177e4 | 6409 | /* Calculate CPU power for physical packages and nodes */ |
a9c9a9b6 PZ |
6410 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
6411 | if (!cpumask_test_cpu(i, cpu_map)) | |
6412 | continue; | |
9c1cfda2 | 6413 | |
dce840a0 PZ |
6414 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
6415 | claim_allocations(i, sd); | |
cd4ea6ae | 6416 | init_sched_groups_power(i, sd); |
dce840a0 | 6417 | } |
f712c0c7 | 6418 | } |
9c1cfda2 | 6419 | |
1da177e4 | 6420 | /* Attach the domains */ |
dce840a0 | 6421 | rcu_read_lock(); |
abcd083a | 6422 | for_each_cpu(i, cpu_map) { |
21d42ccf | 6423 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 6424 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 6425 | } |
dce840a0 | 6426 | rcu_read_unlock(); |
51888ca2 | 6427 | |
822ff793 | 6428 | ret = 0; |
51888ca2 | 6429 | error: |
2109b99e | 6430 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 6431 | return ret; |
1da177e4 | 6432 | } |
029190c5 | 6433 | |
acc3f5d7 | 6434 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 6435 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
6436 | static struct sched_domain_attr *dattr_cur; |
6437 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
6438 | |
6439 | /* | |
6440 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
6441 | * cpumask) fails, then fallback to a single sched domain, |
6442 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 6443 | */ |
4212823f | 6444 | static cpumask_var_t fallback_doms; |
029190c5 | 6445 | |
ee79d1bd HC |
6446 | /* |
6447 | * arch_update_cpu_topology lets virtualized architectures update the | |
6448 | * cpu core maps. It is supposed to return 1 if the topology changed | |
6449 | * or 0 if it stayed the same. | |
6450 | */ | |
6451 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 6452 | { |
ee79d1bd | 6453 | return 0; |
22e52b07 HC |
6454 | } |
6455 | ||
acc3f5d7 RR |
6456 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
6457 | { | |
6458 | int i; | |
6459 | cpumask_var_t *doms; | |
6460 | ||
6461 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
6462 | if (!doms) | |
6463 | return NULL; | |
6464 | for (i = 0; i < ndoms; i++) { | |
6465 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
6466 | free_sched_domains(doms, i); | |
6467 | return NULL; | |
6468 | } | |
6469 | } | |
6470 | return doms; | |
6471 | } | |
6472 | ||
6473 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
6474 | { | |
6475 | unsigned int i; | |
6476 | for (i = 0; i < ndoms; i++) | |
6477 | free_cpumask_var(doms[i]); | |
6478 | kfree(doms); | |
6479 | } | |
6480 | ||
1a20ff27 | 6481 | /* |
41a2d6cf | 6482 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
6483 | * For now this just excludes isolated cpus, but could be used to |
6484 | * exclude other special cases in the future. | |
1a20ff27 | 6485 | */ |
c4a8849a | 6486 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 6487 | { |
7378547f MM |
6488 | int err; |
6489 | ||
22e52b07 | 6490 | arch_update_cpu_topology(); |
029190c5 | 6491 | ndoms_cur = 1; |
acc3f5d7 | 6492 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 6493 | if (!doms_cur) |
acc3f5d7 RR |
6494 | doms_cur = &fallback_doms; |
6495 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
dce840a0 | 6496 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 6497 | register_sched_domain_sysctl(); |
7378547f MM |
6498 | |
6499 | return err; | |
1a20ff27 DG |
6500 | } |
6501 | ||
1a20ff27 DG |
6502 | /* |
6503 | * Detach sched domains from a group of cpus specified in cpu_map | |
6504 | * These cpus will now be attached to the NULL domain | |
6505 | */ | |
96f874e2 | 6506 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
6507 | { |
6508 | int i; | |
6509 | ||
dce840a0 | 6510 | rcu_read_lock(); |
abcd083a | 6511 | for_each_cpu(i, cpu_map) |
57d885fe | 6512 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 6513 | rcu_read_unlock(); |
1a20ff27 DG |
6514 | } |
6515 | ||
1d3504fc HS |
6516 | /* handle null as "default" */ |
6517 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
6518 | struct sched_domain_attr *new, int idx_new) | |
6519 | { | |
6520 | struct sched_domain_attr tmp; | |
6521 | ||
6522 | /* fast path */ | |
6523 | if (!new && !cur) | |
6524 | return 1; | |
6525 | ||
6526 | tmp = SD_ATTR_INIT; | |
6527 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
6528 | new ? (new + idx_new) : &tmp, | |
6529 | sizeof(struct sched_domain_attr)); | |
6530 | } | |
6531 | ||
029190c5 PJ |
6532 | /* |
6533 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 6534 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
6535 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
6536 | * It destroys each deleted domain and builds each new domain. | |
6537 | * | |
acc3f5d7 | 6538 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
6539 | * The masks don't intersect (don't overlap.) We should setup one |
6540 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
6541 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
6542 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
6543 | * it as it is. | |
6544 | * | |
acc3f5d7 RR |
6545 | * The passed in 'doms_new' should be allocated using |
6546 | * alloc_sched_domains. This routine takes ownership of it and will | |
6547 | * free_sched_domains it when done with it. If the caller failed the | |
6548 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
6549 | * and partition_sched_domains() will fallback to the single partition | |
6550 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 6551 | * |
96f874e2 | 6552 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
6553 | * ndoms_new == 0 is a special case for destroying existing domains, |
6554 | * and it will not create the default domain. | |
dfb512ec | 6555 | * |
029190c5 PJ |
6556 | * Call with hotplug lock held |
6557 | */ | |
acc3f5d7 | 6558 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 6559 | struct sched_domain_attr *dattr_new) |
029190c5 | 6560 | { |
dfb512ec | 6561 | int i, j, n; |
d65bd5ec | 6562 | int new_topology; |
029190c5 | 6563 | |
712555ee | 6564 | mutex_lock(&sched_domains_mutex); |
a1835615 | 6565 | |
7378547f MM |
6566 | /* always unregister in case we don't destroy any domains */ |
6567 | unregister_sched_domain_sysctl(); | |
6568 | ||
d65bd5ec HC |
6569 | /* Let architecture update cpu core mappings. */ |
6570 | new_topology = arch_update_cpu_topology(); | |
6571 | ||
dfb512ec | 6572 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
6573 | |
6574 | /* Destroy deleted domains */ | |
6575 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 6576 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6577 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 6578 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
6579 | goto match1; |
6580 | } | |
6581 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 6582 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
6583 | match1: |
6584 | ; | |
6585 | } | |
6586 | ||
e761b772 MK |
6587 | if (doms_new == NULL) { |
6588 | ndoms_cur = 0; | |
acc3f5d7 | 6589 | doms_new = &fallback_doms; |
6ad4c188 | 6590 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 6591 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
6592 | } |
6593 | ||
029190c5 PJ |
6594 | /* Build new domains */ |
6595 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 6596 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 6597 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 6598 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
6599 | goto match2; |
6600 | } | |
6601 | /* no match - add a new doms_new */ | |
dce840a0 | 6602 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
6603 | match2: |
6604 | ; | |
6605 | } | |
6606 | ||
6607 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
6608 | if (doms_cur != &fallback_doms) |
6609 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 6610 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 6611 | doms_cur = doms_new; |
1d3504fc | 6612 | dattr_cur = dattr_new; |
029190c5 | 6613 | ndoms_cur = ndoms_new; |
7378547f MM |
6614 | |
6615 | register_sched_domain_sysctl(); | |
a1835615 | 6616 | |
712555ee | 6617 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
6618 | } |
6619 | ||
d35be8ba SB |
6620 | static int num_cpus_frozen; /* used to mark begin/end of suspend/resume */ |
6621 | ||
1da177e4 | 6622 | /* |
3a101d05 TH |
6623 | * Update cpusets according to cpu_active mask. If cpusets are |
6624 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
6625 | * around partition_sched_domains(). | |
d35be8ba SB |
6626 | * |
6627 | * If we come here as part of a suspend/resume, don't touch cpusets because we | |
6628 | * want to restore it back to its original state upon resume anyway. | |
1da177e4 | 6629 | */ |
0b2e918a TH |
6630 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
6631 | void *hcpu) | |
e761b772 | 6632 | { |
d35be8ba SB |
6633 | switch (action) { |
6634 | case CPU_ONLINE_FROZEN: | |
6635 | case CPU_DOWN_FAILED_FROZEN: | |
6636 | ||
6637 | /* | |
6638 | * num_cpus_frozen tracks how many CPUs are involved in suspend | |
6639 | * resume sequence. As long as this is not the last online | |
6640 | * operation in the resume sequence, just build a single sched | |
6641 | * domain, ignoring cpusets. | |
6642 | */ | |
6643 | num_cpus_frozen--; | |
6644 | if (likely(num_cpus_frozen)) { | |
6645 | partition_sched_domains(1, NULL, NULL); | |
6646 | break; | |
6647 | } | |
6648 | ||
6649 | /* | |
6650 | * This is the last CPU online operation. So fall through and | |
6651 | * restore the original sched domains by considering the | |
6652 | * cpuset configurations. | |
6653 | */ | |
6654 | ||
e761b772 | 6655 | case CPU_ONLINE: |
6ad4c188 | 6656 | case CPU_DOWN_FAILED: |
7ddf96b0 | 6657 | cpuset_update_active_cpus(true); |
d35be8ba | 6658 | break; |
3a101d05 TH |
6659 | default: |
6660 | return NOTIFY_DONE; | |
6661 | } | |
d35be8ba | 6662 | return NOTIFY_OK; |
3a101d05 | 6663 | } |
e761b772 | 6664 | |
0b2e918a TH |
6665 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
6666 | void *hcpu) | |
3a101d05 | 6667 | { |
d35be8ba | 6668 | switch (action) { |
3a101d05 | 6669 | case CPU_DOWN_PREPARE: |
7ddf96b0 | 6670 | cpuset_update_active_cpus(false); |
d35be8ba SB |
6671 | break; |
6672 | case CPU_DOWN_PREPARE_FROZEN: | |
6673 | num_cpus_frozen++; | |
6674 | partition_sched_domains(1, NULL, NULL); | |
6675 | break; | |
e761b772 MK |
6676 | default: |
6677 | return NOTIFY_DONE; | |
6678 | } | |
d35be8ba | 6679 | return NOTIFY_OK; |
e761b772 | 6680 | } |
e761b772 | 6681 | |
1da177e4 LT |
6682 | void __init sched_init_smp(void) |
6683 | { | |
dcc30a35 RR |
6684 | cpumask_var_t non_isolated_cpus; |
6685 | ||
6686 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 6687 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 6688 | |
cb83b629 PZ |
6689 | sched_init_numa(); |
6690 | ||
95402b38 | 6691 | get_online_cpus(); |
712555ee | 6692 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 6693 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
6694 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
6695 | if (cpumask_empty(non_isolated_cpus)) | |
6696 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 6697 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 6698 | put_online_cpus(); |
e761b772 | 6699 | |
301a5cba | 6700 | hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE); |
3a101d05 TH |
6701 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
6702 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 MK |
6703 | |
6704 | /* RT runtime code needs to handle some hotplug events */ | |
6705 | hotcpu_notifier(update_runtime, 0); | |
6706 | ||
b328ca18 | 6707 | init_hrtick(); |
5c1e1767 NP |
6708 | |
6709 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 6710 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 6711 | BUG(); |
19978ca6 | 6712 | sched_init_granularity(); |
dcc30a35 | 6713 | free_cpumask_var(non_isolated_cpus); |
4212823f | 6714 | |
0e3900e6 | 6715 | init_sched_rt_class(); |
1da177e4 LT |
6716 | } |
6717 | #else | |
6718 | void __init sched_init_smp(void) | |
6719 | { | |
19978ca6 | 6720 | sched_init_granularity(); |
1da177e4 LT |
6721 | } |
6722 | #endif /* CONFIG_SMP */ | |
6723 | ||
cd1bb94b AB |
6724 | const_debug unsigned int sysctl_timer_migration = 1; |
6725 | ||
1da177e4 LT |
6726 | int in_sched_functions(unsigned long addr) |
6727 | { | |
1da177e4 LT |
6728 | return in_lock_functions(addr) || |
6729 | (addr >= (unsigned long)__sched_text_start | |
6730 | && addr < (unsigned long)__sched_text_end); | |
6731 | } | |
6732 | ||
029632fb PZ |
6733 | #ifdef CONFIG_CGROUP_SCHED |
6734 | struct task_group root_task_group; | |
35cf4e50 | 6735 | LIST_HEAD(task_groups); |
052f1dc7 | 6736 | #endif |
6f505b16 | 6737 | |
029632fb | 6738 | DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask); |
6f505b16 | 6739 | |
1da177e4 LT |
6740 | void __init sched_init(void) |
6741 | { | |
dd41f596 | 6742 | int i, j; |
434d53b0 MT |
6743 | unsigned long alloc_size = 0, ptr; |
6744 | ||
6745 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
6746 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
6747 | #endif | |
6748 | #ifdef CONFIG_RT_GROUP_SCHED | |
6749 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 6750 | #endif |
df7c8e84 | 6751 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 6752 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 6753 | #endif |
434d53b0 | 6754 | if (alloc_size) { |
36b7b6d4 | 6755 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
6756 | |
6757 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 6758 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
6759 | ptr += nr_cpu_ids * sizeof(void **); |
6760 | ||
07e06b01 | 6761 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 6762 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 6763 | |
6d6bc0ad | 6764 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 6765 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6766 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
6767 | ptr += nr_cpu_ids * sizeof(void **); |
6768 | ||
07e06b01 | 6769 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
6770 | ptr += nr_cpu_ids * sizeof(void **); |
6771 | ||
6d6bc0ad | 6772 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
6773 | #ifdef CONFIG_CPUMASK_OFFSTACK |
6774 | for_each_possible_cpu(i) { | |
6775 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
6776 | ptr += cpumask_size(); | |
6777 | } | |
6778 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 6779 | } |
dd41f596 | 6780 | |
57d885fe GH |
6781 | #ifdef CONFIG_SMP |
6782 | init_defrootdomain(); | |
6783 | #endif | |
6784 | ||
d0b27fa7 PZ |
6785 | init_rt_bandwidth(&def_rt_bandwidth, |
6786 | global_rt_period(), global_rt_runtime()); | |
6787 | ||
6788 | #ifdef CONFIG_RT_GROUP_SCHED | |
07e06b01 | 6789 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 6790 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 6791 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 6792 | |
7c941438 | 6793 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
6794 | list_add(&root_task_group.list, &task_groups); |
6795 | INIT_LIST_HEAD(&root_task_group.children); | |
f4d6f6c2 | 6796 | INIT_LIST_HEAD(&root_task_group.siblings); |
5091faa4 | 6797 | autogroup_init(&init_task); |
54c707e9 | 6798 | |
7c941438 | 6799 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 6800 | |
54c707e9 GC |
6801 | #ifdef CONFIG_CGROUP_CPUACCT |
6802 | root_cpuacct.cpustat = &kernel_cpustat; | |
6803 | root_cpuacct.cpuusage = alloc_percpu(u64); | |
6804 | /* Too early, not expected to fail */ | |
6805 | BUG_ON(!root_cpuacct.cpuusage); | |
6806 | #endif | |
0a945022 | 6807 | for_each_possible_cpu(i) { |
70b97a7f | 6808 | struct rq *rq; |
1da177e4 LT |
6809 | |
6810 | rq = cpu_rq(i); | |
05fa785c | 6811 | raw_spin_lock_init(&rq->lock); |
7897986b | 6812 | rq->nr_running = 0; |
dce48a84 TG |
6813 | rq->calc_load_active = 0; |
6814 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 6815 | init_cfs_rq(&rq->cfs); |
6f505b16 | 6816 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 6817 | #ifdef CONFIG_FAIR_GROUP_SCHED |
029632fb | 6818 | root_task_group.shares = ROOT_TASK_GROUP_LOAD; |
6f505b16 | 6819 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 6820 | /* |
07e06b01 | 6821 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
6822 | * |
6823 | * In case of task-groups formed thr' the cgroup filesystem, it | |
6824 | * gets 100% of the cpu resources in the system. This overall | |
6825 | * system cpu resource is divided among the tasks of | |
07e06b01 | 6826 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
6827 | * based on each entity's (task or task-group's) weight |
6828 | * (se->load.weight). | |
6829 | * | |
07e06b01 | 6830 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
6831 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
6832 | * then A0's share of the cpu resource is: | |
6833 | * | |
0d905bca | 6834 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 6835 | * |
07e06b01 YZ |
6836 | * We achieve this by letting root_task_group's tasks sit |
6837 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 6838 | */ |
ab84d31e | 6839 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 6840 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
6841 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
6842 | ||
6843 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 6844 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 6845 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
07e06b01 | 6846 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 6847 | #endif |
1da177e4 | 6848 | |
dd41f596 IM |
6849 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
6850 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
6851 | |
6852 | rq->last_load_update_tick = jiffies; | |
6853 | ||
1da177e4 | 6854 | #ifdef CONFIG_SMP |
41c7ce9a | 6855 | rq->sd = NULL; |
57d885fe | 6856 | rq->rd = NULL; |
1399fa78 | 6857 | rq->cpu_power = SCHED_POWER_SCALE; |
3f029d3c | 6858 | rq->post_schedule = 0; |
1da177e4 | 6859 | rq->active_balance = 0; |
dd41f596 | 6860 | rq->next_balance = jiffies; |
1da177e4 | 6861 | rq->push_cpu = 0; |
0a2966b4 | 6862 | rq->cpu = i; |
1f11eb6a | 6863 | rq->online = 0; |
eae0c9df MG |
6864 | rq->idle_stamp = 0; |
6865 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
367456c7 PZ |
6866 | |
6867 | INIT_LIST_HEAD(&rq->cfs_tasks); | |
6868 | ||
dc938520 | 6869 | rq_attach_root(rq, &def_root_domain); |
83cd4fe2 | 6870 | #ifdef CONFIG_NO_HZ |
1c792db7 | 6871 | rq->nohz_flags = 0; |
83cd4fe2 | 6872 | #endif |
1da177e4 | 6873 | #endif |
8f4d37ec | 6874 | init_rq_hrtick(rq); |
1da177e4 | 6875 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
6876 | } |
6877 | ||
2dd73a4f | 6878 | set_load_weight(&init_task); |
b50f60ce | 6879 | |
e107be36 AK |
6880 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
6881 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
6882 | #endif | |
6883 | ||
b50f60ce | 6884 | #ifdef CONFIG_RT_MUTEXES |
732375c6 | 6885 | plist_head_init(&init_task.pi_waiters); |
b50f60ce HC |
6886 | #endif |
6887 | ||
1da177e4 LT |
6888 | /* |
6889 | * The boot idle thread does lazy MMU switching as well: | |
6890 | */ | |
6891 | atomic_inc(&init_mm.mm_count); | |
6892 | enter_lazy_tlb(&init_mm, current); | |
6893 | ||
6894 | /* | |
6895 | * Make us the idle thread. Technically, schedule() should not be | |
6896 | * called from this thread, however somewhere below it might be, | |
6897 | * but because we are the idle thread, we just pick up running again | |
6898 | * when this runqueue becomes "idle". | |
6899 | */ | |
6900 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
6901 | |
6902 | calc_load_update = jiffies + LOAD_FREQ; | |
6903 | ||
dd41f596 IM |
6904 | /* |
6905 | * During early bootup we pretend to be a normal task: | |
6906 | */ | |
6907 | current->sched_class = &fair_sched_class; | |
6892b75e | 6908 | |
bf4d83f6 | 6909 | #ifdef CONFIG_SMP |
4cb98839 | 6910 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
bdddd296 RR |
6911 | /* May be allocated at isolcpus cmdline parse time */ |
6912 | if (cpu_isolated_map == NULL) | |
6913 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
29d5e047 | 6914 | idle_thread_set_boot_cpu(); |
029632fb PZ |
6915 | #endif |
6916 | init_sched_fair_class(); | |
6a7b3dc3 | 6917 | |
6892b75e | 6918 | scheduler_running = 1; |
1da177e4 LT |
6919 | } |
6920 | ||
d902db1e | 6921 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
6922 | static inline int preempt_count_equals(int preempt_offset) |
6923 | { | |
234da7bc | 6924 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 6925 | |
4ba8216c | 6926 | return (nested == preempt_offset); |
e4aafea2 FW |
6927 | } |
6928 | ||
d894837f | 6929 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 6930 | { |
1da177e4 LT |
6931 | static unsigned long prev_jiffy; /* ratelimiting */ |
6932 | ||
b3fbab05 | 6933 | rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */ |
e4aafea2 FW |
6934 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
6935 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
6936 | return; |
6937 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
6938 | return; | |
6939 | prev_jiffy = jiffies; | |
6940 | ||
3df0fc5b PZ |
6941 | printk(KERN_ERR |
6942 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
6943 | file, line); | |
6944 | printk(KERN_ERR | |
6945 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
6946 | in_atomic(), irqs_disabled(), | |
6947 | current->pid, current->comm); | |
aef745fc IM |
6948 | |
6949 | debug_show_held_locks(current); | |
6950 | if (irqs_disabled()) | |
6951 | print_irqtrace_events(current); | |
6952 | dump_stack(); | |
1da177e4 LT |
6953 | } |
6954 | EXPORT_SYMBOL(__might_sleep); | |
6955 | #endif | |
6956 | ||
6957 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
6958 | static void normalize_task(struct rq *rq, struct task_struct *p) |
6959 | { | |
da7a735e PZ |
6960 | const struct sched_class *prev_class = p->sched_class; |
6961 | int old_prio = p->prio; | |
3a5e4dc1 | 6962 | int on_rq; |
3e51f33f | 6963 | |
fd2f4419 | 6964 | on_rq = p->on_rq; |
3a5e4dc1 | 6965 | if (on_rq) |
4ca9b72b | 6966 | dequeue_task(rq, p, 0); |
3a5e4dc1 AK |
6967 | __setscheduler(rq, p, SCHED_NORMAL, 0); |
6968 | if (on_rq) { | |
4ca9b72b | 6969 | enqueue_task(rq, p, 0); |
3a5e4dc1 AK |
6970 | resched_task(rq->curr); |
6971 | } | |
da7a735e PZ |
6972 | |
6973 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
6974 | } |
6975 | ||
1da177e4 LT |
6976 | void normalize_rt_tasks(void) |
6977 | { | |
a0f98a1c | 6978 | struct task_struct *g, *p; |
1da177e4 | 6979 | unsigned long flags; |
70b97a7f | 6980 | struct rq *rq; |
1da177e4 | 6981 | |
4cf5d77a | 6982 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 6983 | do_each_thread(g, p) { |
178be793 IM |
6984 | /* |
6985 | * Only normalize user tasks: | |
6986 | */ | |
6987 | if (!p->mm) | |
6988 | continue; | |
6989 | ||
6cfb0d5d | 6990 | p->se.exec_start = 0; |
6cfb0d5d | 6991 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
6992 | p->se.statistics.wait_start = 0; |
6993 | p->se.statistics.sleep_start = 0; | |
6994 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 6995 | #endif |
dd41f596 IM |
6996 | |
6997 | if (!rt_task(p)) { | |
6998 | /* | |
6999 | * Renice negative nice level userspace | |
7000 | * tasks back to 0: | |
7001 | */ | |
7002 | if (TASK_NICE(p) < 0 && p->mm) | |
7003 | set_user_nice(p, 0); | |
1da177e4 | 7004 | continue; |
dd41f596 | 7005 | } |
1da177e4 | 7006 | |
1d615482 | 7007 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7008 | rq = __task_rq_lock(p); |
1da177e4 | 7009 | |
178be793 | 7010 | normalize_task(rq, p); |
3a5e4dc1 | 7011 | |
b29739f9 | 7012 | __task_rq_unlock(rq); |
1d615482 | 7013 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7014 | } while_each_thread(g, p); |
7015 | ||
4cf5d77a | 7016 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7017 | } |
7018 | ||
7019 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7020 | |
67fc4e0c | 7021 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7022 | /* |
67fc4e0c | 7023 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7024 | * |
7025 | * They can only be called when the whole system has been | |
7026 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7027 | * activity can take place. Using them for anything else would | |
7028 | * be a serious bug, and as a result, they aren't even visible | |
7029 | * under any other configuration. | |
7030 | */ | |
7031 | ||
7032 | /** | |
7033 | * curr_task - return the current task for a given cpu. | |
7034 | * @cpu: the processor in question. | |
7035 | * | |
7036 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7037 | */ | |
36c8b586 | 7038 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7039 | { |
7040 | return cpu_curr(cpu); | |
7041 | } | |
7042 | ||
67fc4e0c JW |
7043 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7044 | ||
7045 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7046 | /** |
7047 | * set_curr_task - set the current task for a given cpu. | |
7048 | * @cpu: the processor in question. | |
7049 | * @p: the task pointer to set. | |
7050 | * | |
7051 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7052 | * are serviced on a separate stack. It allows the architecture to switch the |
7053 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7054 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7055 | * and caller must save the original value of the current task (see | |
7056 | * curr_task() above) and restore that value before reenabling interrupts and | |
7057 | * re-starting the system. | |
7058 | * | |
7059 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7060 | */ | |
36c8b586 | 7061 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7062 | { |
7063 | cpu_curr(cpu) = p; | |
7064 | } | |
7065 | ||
7066 | #endif | |
29f59db3 | 7067 | |
7c941438 | 7068 | #ifdef CONFIG_CGROUP_SCHED |
029632fb PZ |
7069 | /* task_group_lock serializes the addition/removal of task groups */ |
7070 | static DEFINE_SPINLOCK(task_group_lock); | |
7071 | ||
bccbe08a PZ |
7072 | static void free_sched_group(struct task_group *tg) |
7073 | { | |
7074 | free_fair_sched_group(tg); | |
7075 | free_rt_sched_group(tg); | |
e9aa1dd1 | 7076 | autogroup_free(tg); |
bccbe08a PZ |
7077 | kfree(tg); |
7078 | } | |
7079 | ||
7080 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 7081 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
7082 | { |
7083 | struct task_group *tg; | |
7084 | unsigned long flags; | |
bccbe08a PZ |
7085 | |
7086 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
7087 | if (!tg) | |
7088 | return ERR_PTR(-ENOMEM); | |
7089 | ||
ec7dc8ac | 7090 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
7091 | goto err; |
7092 | ||
ec7dc8ac | 7093 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
7094 | goto err; |
7095 | ||
8ed36996 | 7096 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 7097 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
7098 | |
7099 | WARN_ON(!parent); /* root should already exist */ | |
7100 | ||
7101 | tg->parent = parent; | |
f473aa5e | 7102 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 7103 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 7104 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 7105 | |
9b5b7751 | 7106 | return tg; |
29f59db3 SV |
7107 | |
7108 | err: | |
6f505b16 | 7109 | free_sched_group(tg); |
29f59db3 SV |
7110 | return ERR_PTR(-ENOMEM); |
7111 | } | |
7112 | ||
9b5b7751 | 7113 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 7114 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 7115 | { |
29f59db3 | 7116 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 7117 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
7118 | } |
7119 | ||
9b5b7751 | 7120 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 7121 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 7122 | { |
8ed36996 | 7123 | unsigned long flags; |
9b5b7751 | 7124 | int i; |
29f59db3 | 7125 | |
3d4b47b4 PZ |
7126 | /* end participation in shares distribution */ |
7127 | for_each_possible_cpu(i) | |
bccbe08a | 7128 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
7129 | |
7130 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 7131 | list_del_rcu(&tg->list); |
f473aa5e | 7132 | list_del_rcu(&tg->siblings); |
8ed36996 | 7133 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 7134 | |
9b5b7751 | 7135 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 7136 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
7137 | } |
7138 | ||
9b5b7751 | 7139 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
7140 | * The caller of this function should have put the task in its new group |
7141 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
7142 | * reflect its new group. | |
9b5b7751 SV |
7143 | */ |
7144 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 | 7145 | { |
8323f26c | 7146 | struct task_group *tg; |
29f59db3 SV |
7147 | int on_rq, running; |
7148 | unsigned long flags; | |
7149 | struct rq *rq; | |
7150 | ||
7151 | rq = task_rq_lock(tsk, &flags); | |
7152 | ||
051a1d1a | 7153 | running = task_current(rq, tsk); |
fd2f4419 | 7154 | on_rq = tsk->on_rq; |
29f59db3 | 7155 | |
0e1f3483 | 7156 | if (on_rq) |
29f59db3 | 7157 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
7158 | if (unlikely(running)) |
7159 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 7160 | |
8323f26c PZ |
7161 | tg = container_of(task_subsys_state_check(tsk, cpu_cgroup_subsys_id, |
7162 | lockdep_is_held(&tsk->sighand->siglock)), | |
7163 | struct task_group, css); | |
7164 | tg = autogroup_task_group(tsk, tg); | |
7165 | tsk->sched_task_group = tg; | |
7166 | ||
810b3817 | 7167 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
7168 | if (tsk->sched_class->task_move_group) |
7169 | tsk->sched_class->task_move_group(tsk, on_rq); | |
7170 | else | |
810b3817 | 7171 | #endif |
b2b5ce02 | 7172 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 7173 | |
0e1f3483 HS |
7174 | if (unlikely(running)) |
7175 | tsk->sched_class->set_curr_task(rq); | |
7176 | if (on_rq) | |
371fd7e7 | 7177 | enqueue_task(rq, tsk, 0); |
29f59db3 | 7178 | |
0122ec5b | 7179 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 7180 | } |
7c941438 | 7181 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 7182 | |
a790de99 | 7183 | #if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH) |
9f0c1e56 PZ |
7184 | static unsigned long to_ratio(u64 period, u64 runtime) |
7185 | { | |
7186 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 7187 | return 1ULL << 20; |
9f0c1e56 | 7188 | |
9a7e0b18 | 7189 | return div64_u64(runtime << 20, period); |
9f0c1e56 | 7190 | } |
a790de99 PT |
7191 | #endif |
7192 | ||
7193 | #ifdef CONFIG_RT_GROUP_SCHED | |
7194 | /* | |
7195 | * Ensure that the real time constraints are schedulable. | |
7196 | */ | |
7197 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 7198 | |
9a7e0b18 PZ |
7199 | /* Must be called with tasklist_lock held */ |
7200 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 7201 | { |
9a7e0b18 | 7202 | struct task_struct *g, *p; |
b40b2e8e | 7203 | |
9a7e0b18 | 7204 | do_each_thread(g, p) { |
029632fb | 7205 | if (rt_task(p) && task_rq(p)->rt.tg == tg) |
9a7e0b18 PZ |
7206 | return 1; |
7207 | } while_each_thread(g, p); | |
b40b2e8e | 7208 | |
9a7e0b18 PZ |
7209 | return 0; |
7210 | } | |
b40b2e8e | 7211 | |
9a7e0b18 PZ |
7212 | struct rt_schedulable_data { |
7213 | struct task_group *tg; | |
7214 | u64 rt_period; | |
7215 | u64 rt_runtime; | |
7216 | }; | |
b40b2e8e | 7217 | |
a790de99 | 7218 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
7219 | { |
7220 | struct rt_schedulable_data *d = data; | |
7221 | struct task_group *child; | |
7222 | unsigned long total, sum = 0; | |
7223 | u64 period, runtime; | |
b40b2e8e | 7224 | |
9a7e0b18 PZ |
7225 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
7226 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 7227 | |
9a7e0b18 PZ |
7228 | if (tg == d->tg) { |
7229 | period = d->rt_period; | |
7230 | runtime = d->rt_runtime; | |
b40b2e8e | 7231 | } |
b40b2e8e | 7232 | |
4653f803 PZ |
7233 | /* |
7234 | * Cannot have more runtime than the period. | |
7235 | */ | |
7236 | if (runtime > period && runtime != RUNTIME_INF) | |
7237 | return -EINVAL; | |
6f505b16 | 7238 | |
4653f803 PZ |
7239 | /* |
7240 | * Ensure we don't starve existing RT tasks. | |
7241 | */ | |
9a7e0b18 PZ |
7242 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
7243 | return -EBUSY; | |
6f505b16 | 7244 | |
9a7e0b18 | 7245 | total = to_ratio(period, runtime); |
6f505b16 | 7246 | |
4653f803 PZ |
7247 | /* |
7248 | * Nobody can have more than the global setting allows. | |
7249 | */ | |
7250 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
7251 | return -EINVAL; | |
6f505b16 | 7252 | |
4653f803 PZ |
7253 | /* |
7254 | * The sum of our children's runtime should not exceed our own. | |
7255 | */ | |
9a7e0b18 PZ |
7256 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
7257 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
7258 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 7259 | |
9a7e0b18 PZ |
7260 | if (child == d->tg) { |
7261 | period = d->rt_period; | |
7262 | runtime = d->rt_runtime; | |
7263 | } | |
6f505b16 | 7264 | |
9a7e0b18 | 7265 | sum += to_ratio(period, runtime); |
9f0c1e56 | 7266 | } |
6f505b16 | 7267 | |
9a7e0b18 PZ |
7268 | if (sum > total) |
7269 | return -EINVAL; | |
7270 | ||
7271 | return 0; | |
6f505b16 PZ |
7272 | } |
7273 | ||
9a7e0b18 | 7274 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 7275 | { |
8277434e PT |
7276 | int ret; |
7277 | ||
9a7e0b18 PZ |
7278 | struct rt_schedulable_data data = { |
7279 | .tg = tg, | |
7280 | .rt_period = period, | |
7281 | .rt_runtime = runtime, | |
7282 | }; | |
7283 | ||
8277434e PT |
7284 | rcu_read_lock(); |
7285 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
7286 | rcu_read_unlock(); | |
7287 | ||
7288 | return ret; | |
521f1a24 DG |
7289 | } |
7290 | ||
ab84d31e | 7291 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 7292 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 7293 | { |
ac086bc2 | 7294 | int i, err = 0; |
9f0c1e56 | 7295 | |
9f0c1e56 | 7296 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 7297 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
7298 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
7299 | if (err) | |
9f0c1e56 | 7300 | goto unlock; |
ac086bc2 | 7301 | |
0986b11b | 7302 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
7303 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
7304 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
7305 | |
7306 | for_each_possible_cpu(i) { | |
7307 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
7308 | ||
0986b11b | 7309 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7310 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 7311 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7312 | } |
0986b11b | 7313 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 7314 | unlock: |
521f1a24 | 7315 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
7316 | mutex_unlock(&rt_constraints_mutex); |
7317 | ||
7318 | return err; | |
6f505b16 PZ |
7319 | } |
7320 | ||
d0b27fa7 PZ |
7321 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
7322 | { | |
7323 | u64 rt_runtime, rt_period; | |
7324 | ||
7325 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7326 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
7327 | if (rt_runtime_us < 0) | |
7328 | rt_runtime = RUNTIME_INF; | |
7329 | ||
ab84d31e | 7330 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7331 | } |
7332 | ||
9f0c1e56 PZ |
7333 | long sched_group_rt_runtime(struct task_group *tg) |
7334 | { | |
7335 | u64 rt_runtime_us; | |
7336 | ||
d0b27fa7 | 7337 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
7338 | return -1; |
7339 | ||
d0b27fa7 | 7340 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
7341 | do_div(rt_runtime_us, NSEC_PER_USEC); |
7342 | return rt_runtime_us; | |
7343 | } | |
d0b27fa7 PZ |
7344 | |
7345 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
7346 | { | |
7347 | u64 rt_runtime, rt_period; | |
7348 | ||
7349 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
7350 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
7351 | ||
619b0488 R |
7352 | if (rt_period == 0) |
7353 | return -EINVAL; | |
7354 | ||
ab84d31e | 7355 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7356 | } |
7357 | ||
7358 | long sched_group_rt_period(struct task_group *tg) | |
7359 | { | |
7360 | u64 rt_period_us; | |
7361 | ||
7362 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7363 | do_div(rt_period_us, NSEC_PER_USEC); | |
7364 | return rt_period_us; | |
7365 | } | |
7366 | ||
7367 | static int sched_rt_global_constraints(void) | |
7368 | { | |
4653f803 | 7369 | u64 runtime, period; |
d0b27fa7 PZ |
7370 | int ret = 0; |
7371 | ||
ec5d4989 HS |
7372 | if (sysctl_sched_rt_period <= 0) |
7373 | return -EINVAL; | |
7374 | ||
4653f803 PZ |
7375 | runtime = global_rt_runtime(); |
7376 | period = global_rt_period(); | |
7377 | ||
7378 | /* | |
7379 | * Sanity check on the sysctl variables. | |
7380 | */ | |
7381 | if (runtime > period && runtime != RUNTIME_INF) | |
7382 | return -EINVAL; | |
10b612f4 | 7383 | |
d0b27fa7 | 7384 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 7385 | read_lock(&tasklist_lock); |
4653f803 | 7386 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 7387 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
7388 | mutex_unlock(&rt_constraints_mutex); |
7389 | ||
7390 | return ret; | |
7391 | } | |
54e99124 DG |
7392 | |
7393 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
7394 | { | |
7395 | /* Don't accept realtime tasks when there is no way for them to run */ | |
7396 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
7397 | return 0; | |
7398 | ||
7399 | return 1; | |
7400 | } | |
7401 | ||
6d6bc0ad | 7402 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7403 | static int sched_rt_global_constraints(void) |
7404 | { | |
ac086bc2 PZ |
7405 | unsigned long flags; |
7406 | int i; | |
7407 | ||
ec5d4989 HS |
7408 | if (sysctl_sched_rt_period <= 0) |
7409 | return -EINVAL; | |
7410 | ||
60aa605d PZ |
7411 | /* |
7412 | * There's always some RT tasks in the root group | |
7413 | * -- migration, kstopmachine etc.. | |
7414 | */ | |
7415 | if (sysctl_sched_rt_runtime == 0) | |
7416 | return -EBUSY; | |
7417 | ||
0986b11b | 7418 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
7419 | for_each_possible_cpu(i) { |
7420 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
7421 | ||
0986b11b | 7422 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7423 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 7424 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7425 | } |
0986b11b | 7426 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 7427 | |
d0b27fa7 PZ |
7428 | return 0; |
7429 | } | |
6d6bc0ad | 7430 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7431 | |
7432 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 7433 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
7434 | loff_t *ppos) |
7435 | { | |
7436 | int ret; | |
7437 | int old_period, old_runtime; | |
7438 | static DEFINE_MUTEX(mutex); | |
7439 | ||
7440 | mutex_lock(&mutex); | |
7441 | old_period = sysctl_sched_rt_period; | |
7442 | old_runtime = sysctl_sched_rt_runtime; | |
7443 | ||
8d65af78 | 7444 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
7445 | |
7446 | if (!ret && write) { | |
7447 | ret = sched_rt_global_constraints(); | |
7448 | if (ret) { | |
7449 | sysctl_sched_rt_period = old_period; | |
7450 | sysctl_sched_rt_runtime = old_runtime; | |
7451 | } else { | |
7452 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
7453 | def_rt_bandwidth.rt_period = | |
7454 | ns_to_ktime(global_rt_period()); | |
7455 | } | |
7456 | } | |
7457 | mutex_unlock(&mutex); | |
7458 | ||
7459 | return ret; | |
7460 | } | |
68318b8e | 7461 | |
052f1dc7 | 7462 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
7463 | |
7464 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 7465 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 7466 | { |
2b01dfe3 PM |
7467 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
7468 | struct task_group, css); | |
68318b8e SV |
7469 | } |
7470 | ||
761b3ef5 | 7471 | static struct cgroup_subsys_state *cpu_cgroup_create(struct cgroup *cgrp) |
68318b8e | 7472 | { |
ec7dc8ac | 7473 | struct task_group *tg, *parent; |
68318b8e | 7474 | |
2b01dfe3 | 7475 | if (!cgrp->parent) { |
68318b8e | 7476 | /* This is early initialization for the top cgroup */ |
07e06b01 | 7477 | return &root_task_group.css; |
68318b8e SV |
7478 | } |
7479 | ||
ec7dc8ac DG |
7480 | parent = cgroup_tg(cgrp->parent); |
7481 | tg = sched_create_group(parent); | |
68318b8e SV |
7482 | if (IS_ERR(tg)) |
7483 | return ERR_PTR(-ENOMEM); | |
7484 | ||
68318b8e SV |
7485 | return &tg->css; |
7486 | } | |
7487 | ||
761b3ef5 | 7488 | static void cpu_cgroup_destroy(struct cgroup *cgrp) |
68318b8e | 7489 | { |
2b01dfe3 | 7490 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
7491 | |
7492 | sched_destroy_group(tg); | |
7493 | } | |
7494 | ||
761b3ef5 | 7495 | static int cpu_cgroup_can_attach(struct cgroup *cgrp, |
bb9d97b6 | 7496 | struct cgroup_taskset *tset) |
68318b8e | 7497 | { |
bb9d97b6 TH |
7498 | struct task_struct *task; |
7499 | ||
7500 | cgroup_taskset_for_each(task, cgrp, tset) { | |
b68aa230 | 7501 | #ifdef CONFIG_RT_GROUP_SCHED |
bb9d97b6 TH |
7502 | if (!sched_rt_can_attach(cgroup_tg(cgrp), task)) |
7503 | return -EINVAL; | |
b68aa230 | 7504 | #else |
bb9d97b6 TH |
7505 | /* We don't support RT-tasks being in separate groups */ |
7506 | if (task->sched_class != &fair_sched_class) | |
7507 | return -EINVAL; | |
b68aa230 | 7508 | #endif |
bb9d97b6 | 7509 | } |
be367d09 BB |
7510 | return 0; |
7511 | } | |
68318b8e | 7512 | |
761b3ef5 | 7513 | static void cpu_cgroup_attach(struct cgroup *cgrp, |
bb9d97b6 | 7514 | struct cgroup_taskset *tset) |
68318b8e | 7515 | { |
bb9d97b6 TH |
7516 | struct task_struct *task; |
7517 | ||
7518 | cgroup_taskset_for_each(task, cgrp, tset) | |
7519 | sched_move_task(task); | |
68318b8e SV |
7520 | } |
7521 | ||
068c5cc5 | 7522 | static void |
761b3ef5 LZ |
7523 | cpu_cgroup_exit(struct cgroup *cgrp, struct cgroup *old_cgrp, |
7524 | struct task_struct *task) | |
068c5cc5 PZ |
7525 | { |
7526 | /* | |
7527 | * cgroup_exit() is called in the copy_process() failure path. | |
7528 | * Ignore this case since the task hasn't ran yet, this avoids | |
7529 | * trying to poke a half freed task state from generic code. | |
7530 | */ | |
7531 | if (!(task->flags & PF_EXITING)) | |
7532 | return; | |
7533 | ||
7534 | sched_move_task(task); | |
7535 | } | |
7536 | ||
052f1dc7 | 7537 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 7538 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 7539 | u64 shareval) |
68318b8e | 7540 | { |
c8b28116 | 7541 | return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval)); |
68318b8e SV |
7542 | } |
7543 | ||
f4c753b7 | 7544 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 7545 | { |
2b01dfe3 | 7546 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e | 7547 | |
c8b28116 | 7548 | return (u64) scale_load_down(tg->shares); |
68318b8e | 7549 | } |
ab84d31e PT |
7550 | |
7551 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
7552 | static DEFINE_MUTEX(cfs_constraints_mutex); |
7553 | ||
ab84d31e PT |
7554 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
7555 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
7556 | ||
a790de99 PT |
7557 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
7558 | ||
ab84d31e PT |
7559 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
7560 | { | |
56f570e5 | 7561 | int i, ret = 0, runtime_enabled, runtime_was_enabled; |
029632fb | 7562 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
ab84d31e PT |
7563 | |
7564 | if (tg == &root_task_group) | |
7565 | return -EINVAL; | |
7566 | ||
7567 | /* | |
7568 | * Ensure we have at some amount of bandwidth every period. This is | |
7569 | * to prevent reaching a state of large arrears when throttled via | |
7570 | * entity_tick() resulting in prolonged exit starvation. | |
7571 | */ | |
7572 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
7573 | return -EINVAL; | |
7574 | ||
7575 | /* | |
7576 | * Likewise, bound things on the otherside by preventing insane quota | |
7577 | * periods. This also allows us to normalize in computing quota | |
7578 | * feasibility. | |
7579 | */ | |
7580 | if (period > max_cfs_quota_period) | |
7581 | return -EINVAL; | |
7582 | ||
a790de99 PT |
7583 | mutex_lock(&cfs_constraints_mutex); |
7584 | ret = __cfs_schedulable(tg, period, quota); | |
7585 | if (ret) | |
7586 | goto out_unlock; | |
7587 | ||
58088ad0 | 7588 | runtime_enabled = quota != RUNTIME_INF; |
56f570e5 PT |
7589 | runtime_was_enabled = cfs_b->quota != RUNTIME_INF; |
7590 | account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled); | |
ab84d31e PT |
7591 | raw_spin_lock_irq(&cfs_b->lock); |
7592 | cfs_b->period = ns_to_ktime(period); | |
7593 | cfs_b->quota = quota; | |
58088ad0 | 7594 | |
a9cf55b2 | 7595 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
7596 | /* restart the period timer (if active) to handle new period expiry */ |
7597 | if (runtime_enabled && cfs_b->timer_active) { | |
7598 | /* force a reprogram */ | |
7599 | cfs_b->timer_active = 0; | |
7600 | __start_cfs_bandwidth(cfs_b); | |
7601 | } | |
ab84d31e PT |
7602 | raw_spin_unlock_irq(&cfs_b->lock); |
7603 | ||
7604 | for_each_possible_cpu(i) { | |
7605 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; | |
029632fb | 7606 | struct rq *rq = cfs_rq->rq; |
ab84d31e PT |
7607 | |
7608 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 7609 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 7610 | cfs_rq->runtime_remaining = 0; |
671fd9da | 7611 | |
029632fb | 7612 | if (cfs_rq->throttled) |
671fd9da | 7613 | unthrottle_cfs_rq(cfs_rq); |
ab84d31e PT |
7614 | raw_spin_unlock_irq(&rq->lock); |
7615 | } | |
a790de99 PT |
7616 | out_unlock: |
7617 | mutex_unlock(&cfs_constraints_mutex); | |
ab84d31e | 7618 | |
a790de99 | 7619 | return ret; |
ab84d31e PT |
7620 | } |
7621 | ||
7622 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
7623 | { | |
7624 | u64 quota, period; | |
7625 | ||
029632fb | 7626 | period = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7627 | if (cfs_quota_us < 0) |
7628 | quota = RUNTIME_INF; | |
7629 | else | |
7630 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
7631 | ||
7632 | return tg_set_cfs_bandwidth(tg, period, quota); | |
7633 | } | |
7634 | ||
7635 | long tg_get_cfs_quota(struct task_group *tg) | |
7636 | { | |
7637 | u64 quota_us; | |
7638 | ||
029632fb | 7639 | if (tg->cfs_bandwidth.quota == RUNTIME_INF) |
ab84d31e PT |
7640 | return -1; |
7641 | ||
029632fb | 7642 | quota_us = tg->cfs_bandwidth.quota; |
ab84d31e PT |
7643 | do_div(quota_us, NSEC_PER_USEC); |
7644 | ||
7645 | return quota_us; | |
7646 | } | |
7647 | ||
7648 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
7649 | { | |
7650 | u64 quota, period; | |
7651 | ||
7652 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
029632fb | 7653 | quota = tg->cfs_bandwidth.quota; |
ab84d31e | 7654 | |
ab84d31e PT |
7655 | return tg_set_cfs_bandwidth(tg, period, quota); |
7656 | } | |
7657 | ||
7658 | long tg_get_cfs_period(struct task_group *tg) | |
7659 | { | |
7660 | u64 cfs_period_us; | |
7661 | ||
029632fb | 7662 | cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7663 | do_div(cfs_period_us, NSEC_PER_USEC); |
7664 | ||
7665 | return cfs_period_us; | |
7666 | } | |
7667 | ||
7668 | static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft) | |
7669 | { | |
7670 | return tg_get_cfs_quota(cgroup_tg(cgrp)); | |
7671 | } | |
7672 | ||
7673 | static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype, | |
7674 | s64 cfs_quota_us) | |
7675 | { | |
7676 | return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us); | |
7677 | } | |
7678 | ||
7679 | static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft) | |
7680 | { | |
7681 | return tg_get_cfs_period(cgroup_tg(cgrp)); | |
7682 | } | |
7683 | ||
7684 | static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype, | |
7685 | u64 cfs_period_us) | |
7686 | { | |
7687 | return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us); | |
7688 | } | |
7689 | ||
a790de99 PT |
7690 | struct cfs_schedulable_data { |
7691 | struct task_group *tg; | |
7692 | u64 period, quota; | |
7693 | }; | |
7694 | ||
7695 | /* | |
7696 | * normalize group quota/period to be quota/max_period | |
7697 | * note: units are usecs | |
7698 | */ | |
7699 | static u64 normalize_cfs_quota(struct task_group *tg, | |
7700 | struct cfs_schedulable_data *d) | |
7701 | { | |
7702 | u64 quota, period; | |
7703 | ||
7704 | if (tg == d->tg) { | |
7705 | period = d->period; | |
7706 | quota = d->quota; | |
7707 | } else { | |
7708 | period = tg_get_cfs_period(tg); | |
7709 | quota = tg_get_cfs_quota(tg); | |
7710 | } | |
7711 | ||
7712 | /* note: these should typically be equivalent */ | |
7713 | if (quota == RUNTIME_INF || quota == -1) | |
7714 | return RUNTIME_INF; | |
7715 | ||
7716 | return to_ratio(period, quota); | |
7717 | } | |
7718 | ||
7719 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
7720 | { | |
7721 | struct cfs_schedulable_data *d = data; | |
029632fb | 7722 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
a790de99 PT |
7723 | s64 quota = 0, parent_quota = -1; |
7724 | ||
7725 | if (!tg->parent) { | |
7726 | quota = RUNTIME_INF; | |
7727 | } else { | |
029632fb | 7728 | struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth; |
a790de99 PT |
7729 | |
7730 | quota = normalize_cfs_quota(tg, d); | |
7731 | parent_quota = parent_b->hierarchal_quota; | |
7732 | ||
7733 | /* | |
7734 | * ensure max(child_quota) <= parent_quota, inherit when no | |
7735 | * limit is set | |
7736 | */ | |
7737 | if (quota == RUNTIME_INF) | |
7738 | quota = parent_quota; | |
7739 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
7740 | return -EINVAL; | |
7741 | } | |
7742 | cfs_b->hierarchal_quota = quota; | |
7743 | ||
7744 | return 0; | |
7745 | } | |
7746 | ||
7747 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
7748 | { | |
8277434e | 7749 | int ret; |
a790de99 PT |
7750 | struct cfs_schedulable_data data = { |
7751 | .tg = tg, | |
7752 | .period = period, | |
7753 | .quota = quota, | |
7754 | }; | |
7755 | ||
7756 | if (quota != RUNTIME_INF) { | |
7757 | do_div(data.period, NSEC_PER_USEC); | |
7758 | do_div(data.quota, NSEC_PER_USEC); | |
7759 | } | |
7760 | ||
8277434e PT |
7761 | rcu_read_lock(); |
7762 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
7763 | rcu_read_unlock(); | |
7764 | ||
7765 | return ret; | |
a790de99 | 7766 | } |
e8da1b18 NR |
7767 | |
7768 | static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
7769 | struct cgroup_map_cb *cb) | |
7770 | { | |
7771 | struct task_group *tg = cgroup_tg(cgrp); | |
029632fb | 7772 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
e8da1b18 NR |
7773 | |
7774 | cb->fill(cb, "nr_periods", cfs_b->nr_periods); | |
7775 | cb->fill(cb, "nr_throttled", cfs_b->nr_throttled); | |
7776 | cb->fill(cb, "throttled_time", cfs_b->throttled_time); | |
7777 | ||
7778 | return 0; | |
7779 | } | |
ab84d31e | 7780 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 7781 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 7782 | |
052f1dc7 | 7783 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 7784 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 7785 | s64 val) |
6f505b16 | 7786 | { |
06ecb27c | 7787 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
7788 | } |
7789 | ||
06ecb27c | 7790 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 7791 | { |
06ecb27c | 7792 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 7793 | } |
d0b27fa7 PZ |
7794 | |
7795 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
7796 | u64 rt_period_us) | |
7797 | { | |
7798 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
7799 | } | |
7800 | ||
7801 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
7802 | { | |
7803 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
7804 | } | |
6d6bc0ad | 7805 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 7806 | |
fe5c7cc2 | 7807 | static struct cftype cpu_files[] = { |
052f1dc7 | 7808 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
7809 | { |
7810 | .name = "shares", | |
f4c753b7 PM |
7811 | .read_u64 = cpu_shares_read_u64, |
7812 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 7813 | }, |
052f1dc7 | 7814 | #endif |
ab84d31e PT |
7815 | #ifdef CONFIG_CFS_BANDWIDTH |
7816 | { | |
7817 | .name = "cfs_quota_us", | |
7818 | .read_s64 = cpu_cfs_quota_read_s64, | |
7819 | .write_s64 = cpu_cfs_quota_write_s64, | |
7820 | }, | |
7821 | { | |
7822 | .name = "cfs_period_us", | |
7823 | .read_u64 = cpu_cfs_period_read_u64, | |
7824 | .write_u64 = cpu_cfs_period_write_u64, | |
7825 | }, | |
e8da1b18 NR |
7826 | { |
7827 | .name = "stat", | |
7828 | .read_map = cpu_stats_show, | |
7829 | }, | |
ab84d31e | 7830 | #endif |
052f1dc7 | 7831 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 7832 | { |
9f0c1e56 | 7833 | .name = "rt_runtime_us", |
06ecb27c PM |
7834 | .read_s64 = cpu_rt_runtime_read, |
7835 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 7836 | }, |
d0b27fa7 PZ |
7837 | { |
7838 | .name = "rt_period_us", | |
f4c753b7 PM |
7839 | .read_u64 = cpu_rt_period_read_uint, |
7840 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 7841 | }, |
052f1dc7 | 7842 | #endif |
4baf6e33 | 7843 | { } /* terminate */ |
68318b8e SV |
7844 | }; |
7845 | ||
68318b8e | 7846 | struct cgroup_subsys cpu_cgroup_subsys = { |
38605cae IM |
7847 | .name = "cpu", |
7848 | .create = cpu_cgroup_create, | |
7849 | .destroy = cpu_cgroup_destroy, | |
bb9d97b6 TH |
7850 | .can_attach = cpu_cgroup_can_attach, |
7851 | .attach = cpu_cgroup_attach, | |
068c5cc5 | 7852 | .exit = cpu_cgroup_exit, |
38605cae | 7853 | .subsys_id = cpu_cgroup_subsys_id, |
4baf6e33 | 7854 | .base_cftypes = cpu_files, |
68318b8e SV |
7855 | .early_init = 1, |
7856 | }; | |
7857 | ||
052f1dc7 | 7858 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
7859 | |
7860 | #ifdef CONFIG_CGROUP_CPUACCT | |
7861 | ||
7862 | /* | |
7863 | * CPU accounting code for task groups. | |
7864 | * | |
7865 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
7866 | * (balbir@in.ibm.com). | |
7867 | */ | |
7868 | ||
73fbec60 FW |
7869 | struct cpuacct root_cpuacct; |
7870 | ||
d842de87 | 7871 | /* create a new cpu accounting group */ |
761b3ef5 | 7872 | static struct cgroup_subsys_state *cpuacct_create(struct cgroup *cgrp) |
d842de87 | 7873 | { |
54c707e9 | 7874 | struct cpuacct *ca; |
d842de87 | 7875 | |
54c707e9 GC |
7876 | if (!cgrp->parent) |
7877 | return &root_cpuacct.css; | |
7878 | ||
7879 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
d842de87 | 7880 | if (!ca) |
ef12fefa | 7881 | goto out; |
d842de87 SV |
7882 | |
7883 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
7884 | if (!ca->cpuusage) |
7885 | goto out_free_ca; | |
7886 | ||
54c707e9 GC |
7887 | ca->cpustat = alloc_percpu(struct kernel_cpustat); |
7888 | if (!ca->cpustat) | |
7889 | goto out_free_cpuusage; | |
934352f2 | 7890 | |
d842de87 | 7891 | return &ca->css; |
ef12fefa | 7892 | |
54c707e9 | 7893 | out_free_cpuusage: |
ef12fefa BR |
7894 | free_percpu(ca->cpuusage); |
7895 | out_free_ca: | |
7896 | kfree(ca); | |
7897 | out: | |
7898 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
7899 | } |
7900 | ||
7901 | /* destroy an existing cpu accounting group */ | |
761b3ef5 | 7902 | static void cpuacct_destroy(struct cgroup *cgrp) |
d842de87 | 7903 | { |
32cd756a | 7904 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 | 7905 | |
54c707e9 | 7906 | free_percpu(ca->cpustat); |
d842de87 SV |
7907 | free_percpu(ca->cpuusage); |
7908 | kfree(ca); | |
7909 | } | |
7910 | ||
720f5498 KC |
7911 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
7912 | { | |
b36128c8 | 7913 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
7914 | u64 data; |
7915 | ||
7916 | #ifndef CONFIG_64BIT | |
7917 | /* | |
7918 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
7919 | */ | |
05fa785c | 7920 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 7921 | data = *cpuusage; |
05fa785c | 7922 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
7923 | #else |
7924 | data = *cpuusage; | |
7925 | #endif | |
7926 | ||
7927 | return data; | |
7928 | } | |
7929 | ||
7930 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
7931 | { | |
b36128c8 | 7932 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
7933 | |
7934 | #ifndef CONFIG_64BIT | |
7935 | /* | |
7936 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
7937 | */ | |
05fa785c | 7938 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 7939 | *cpuusage = val; |
05fa785c | 7940 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
7941 | #else |
7942 | *cpuusage = val; | |
7943 | #endif | |
7944 | } | |
7945 | ||
d842de87 | 7946 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 7947 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 7948 | { |
32cd756a | 7949 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
7950 | u64 totalcpuusage = 0; |
7951 | int i; | |
7952 | ||
720f5498 KC |
7953 | for_each_present_cpu(i) |
7954 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
7955 | |
7956 | return totalcpuusage; | |
7957 | } | |
7958 | ||
0297b803 DG |
7959 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
7960 | u64 reset) | |
7961 | { | |
7962 | struct cpuacct *ca = cgroup_ca(cgrp); | |
7963 | int err = 0; | |
7964 | int i; | |
7965 | ||
7966 | if (reset) { | |
7967 | err = -EINVAL; | |
7968 | goto out; | |
7969 | } | |
7970 | ||
720f5498 KC |
7971 | for_each_present_cpu(i) |
7972 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 7973 | |
0297b803 DG |
7974 | out: |
7975 | return err; | |
7976 | } | |
7977 | ||
e9515c3c KC |
7978 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
7979 | struct seq_file *m) | |
7980 | { | |
7981 | struct cpuacct *ca = cgroup_ca(cgroup); | |
7982 | u64 percpu; | |
7983 | int i; | |
7984 | ||
7985 | for_each_present_cpu(i) { | |
7986 | percpu = cpuacct_cpuusage_read(ca, i); | |
7987 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
7988 | } | |
7989 | seq_printf(m, "\n"); | |
7990 | return 0; | |
7991 | } | |
7992 | ||
ef12fefa BR |
7993 | static const char *cpuacct_stat_desc[] = { |
7994 | [CPUACCT_STAT_USER] = "user", | |
7995 | [CPUACCT_STAT_SYSTEM] = "system", | |
7996 | }; | |
7997 | ||
7998 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
54c707e9 | 7999 | struct cgroup_map_cb *cb) |
ef12fefa BR |
8000 | { |
8001 | struct cpuacct *ca = cgroup_ca(cgrp); | |
54c707e9 GC |
8002 | int cpu; |
8003 | s64 val = 0; | |
ef12fefa | 8004 | |
54c707e9 GC |
8005 | for_each_online_cpu(cpu) { |
8006 | struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); | |
8007 | val += kcpustat->cpustat[CPUTIME_USER]; | |
8008 | val += kcpustat->cpustat[CPUTIME_NICE]; | |
ef12fefa | 8009 | } |
54c707e9 GC |
8010 | val = cputime64_to_clock_t(val); |
8011 | cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val); | |
ef12fefa | 8012 | |
54c707e9 GC |
8013 | val = 0; |
8014 | for_each_online_cpu(cpu) { | |
8015 | struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu); | |
8016 | val += kcpustat->cpustat[CPUTIME_SYSTEM]; | |
8017 | val += kcpustat->cpustat[CPUTIME_IRQ]; | |
8018 | val += kcpustat->cpustat[CPUTIME_SOFTIRQ]; | |
ef12fefa | 8019 | } |
54c707e9 GC |
8020 | |
8021 | val = cputime64_to_clock_t(val); | |
8022 | cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val); | |
8023 | ||
ef12fefa BR |
8024 | return 0; |
8025 | } | |
8026 | ||
d842de87 SV |
8027 | static struct cftype files[] = { |
8028 | { | |
8029 | .name = "usage", | |
f4c753b7 PM |
8030 | .read_u64 = cpuusage_read, |
8031 | .write_u64 = cpuusage_write, | |
d842de87 | 8032 | }, |
e9515c3c KC |
8033 | { |
8034 | .name = "usage_percpu", | |
8035 | .read_seq_string = cpuacct_percpu_seq_read, | |
8036 | }, | |
ef12fefa BR |
8037 | { |
8038 | .name = "stat", | |
8039 | .read_map = cpuacct_stats_show, | |
8040 | }, | |
4baf6e33 | 8041 | { } /* terminate */ |
d842de87 SV |
8042 | }; |
8043 | ||
d842de87 SV |
8044 | /* |
8045 | * charge this task's execution time to its accounting group. | |
8046 | * | |
8047 | * called with rq->lock held. | |
8048 | */ | |
029632fb | 8049 | void cpuacct_charge(struct task_struct *tsk, u64 cputime) |
d842de87 SV |
8050 | { |
8051 | struct cpuacct *ca; | |
934352f2 | 8052 | int cpu; |
d842de87 | 8053 | |
c40c6f85 | 8054 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
8055 | return; |
8056 | ||
934352f2 | 8057 | cpu = task_cpu(tsk); |
a18b83b7 BR |
8058 | |
8059 | rcu_read_lock(); | |
8060 | ||
d842de87 | 8061 | ca = task_ca(tsk); |
d842de87 | 8062 | |
44252e42 | 8063 | for (; ca; ca = parent_ca(ca)) { |
b36128c8 | 8064 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
8065 | *cpuusage += cputime; |
8066 | } | |
a18b83b7 BR |
8067 | |
8068 | rcu_read_unlock(); | |
d842de87 SV |
8069 | } |
8070 | ||
8071 | struct cgroup_subsys cpuacct_subsys = { | |
8072 | .name = "cpuacct", | |
8073 | .create = cpuacct_create, | |
8074 | .destroy = cpuacct_destroy, | |
d842de87 | 8075 | .subsys_id = cpuacct_subsys_id, |
4baf6e33 | 8076 | .base_cftypes = files, |
d842de87 SV |
8077 | }; |
8078 | #endif /* CONFIG_CGROUP_CPUACCT */ |