1
2
3
4
5
6#include "sched.h"
7
8#include <linux/slab.h>
9#include <linux/irq_work.h>
10
11int sched_rr_timeslice = RR_TIMESLICE;
12
13static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
14
15struct rt_bandwidth def_rt_bandwidth;
16
17static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)
18{
19 struct rt_bandwidth *rt_b =
20 container_of(timer, struct rt_bandwidth, rt_period_timer);
21 int idle = 0;
22 int overrun;
23
24 raw_spin_lock(&rt_b->rt_runtime_lock);
25 for (;;) {
26 overrun = hrtimer_forward_now(timer, rt_b->rt_period);
27 if (!overrun)
28 break;
29
30 raw_spin_unlock(&rt_b->rt_runtime_lock);
31 idle = do_sched_rt_period_timer(rt_b, overrun);
32 raw_spin_lock(&rt_b->rt_runtime_lock);
33 }
34 if (idle)
35 rt_b->rt_period_active = 0;
36 raw_spin_unlock(&rt_b->rt_runtime_lock);
37
38 return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
39}
40
41void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
42{
43 rt_b->rt_period = ns_to_ktime(period);
44 rt_b->rt_runtime = runtime;
45
46 raw_spin_lock_init(&rt_b->rt_runtime_lock);
47
48 hrtimer_init(&rt_b->rt_period_timer,
49 CLOCK_MONOTONIC, HRTIMER_MODE_REL);
50 rt_b->rt_period_timer.function = sched_rt_period_timer;
51}
52
53static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
54{
55 if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
56 return;
57
58 raw_spin_lock(&rt_b->rt_runtime_lock);
59 if (!rt_b->rt_period_active) {
60 rt_b->rt_period_active = 1;
61
62
63
64
65
66
67
68
69 hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0));
70 hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED);
71 }
72 raw_spin_unlock(&rt_b->rt_runtime_lock);
73}
74
75#if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI)
76static void push_irq_work_func(struct irq_work *work);
77#endif
78
79void init_rt_rq(struct rt_rq *rt_rq)
80{
81 struct rt_prio_array *array;
82 int i;
83
84 array = &rt_rq->active;
85 for (i = 0; i < MAX_RT_PRIO; i++) {
86 INIT_LIST_HEAD(array->queue + i);
87 __clear_bit(i, array->bitmap);
88 }
89
90 __set_bit(MAX_RT_PRIO, array->bitmap);
91
92#if defined CONFIG_SMP
93 rt_rq->highest_prio.curr = MAX_RT_PRIO;
94 rt_rq->highest_prio.next = MAX_RT_PRIO;
95 rt_rq->rt_nr_migratory = 0;
96 rt_rq->overloaded = 0;
97 plist_head_init(&rt_rq->pushable_tasks);
98
99#ifdef HAVE_RT_PUSH_IPI
100 rt_rq->push_flags = 0;
101 rt_rq->push_cpu = nr_cpu_ids;
102 raw_spin_lock_init(&rt_rq->push_lock);
103 init_irq_work(&rt_rq->push_work, push_irq_work_func);
104#endif
105#endif
106
107 rt_rq->rt_queued = 0;
108
109 rt_rq->rt_time = 0;
110 rt_rq->rt_throttled = 0;
111 rt_rq->rt_runtime = 0;
112 raw_spin_lock_init(&rt_rq->rt_runtime_lock);
113}
114
115#ifdef CONFIG_RT_GROUP_SCHED
116static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
117{
118 hrtimer_cancel(&rt_b->rt_period_timer);
119}
120
121#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
122
123static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
124{
125#ifdef CONFIG_SCHED_DEBUG
126 WARN_ON_ONCE(!rt_entity_is_task(rt_se));
127#endif
128 return container_of(rt_se, struct task_struct, rt);
129}
130
131static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
132{
133 return rt_rq->rq;
134}
135
136static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
137{
138 return rt_se->rt_rq;
139}
140
141static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
142{
143 struct rt_rq *rt_rq = rt_se->rt_rq;
144
145 return rt_rq->rq;
146}
147
148void free_rt_sched_group(struct task_group *tg)
149{
150 int i;
151
152 if (tg->rt_se)
153 destroy_rt_bandwidth(&tg->rt_bandwidth);
154
155 for_each_possible_cpu(i) {
156 if (tg->rt_rq)
157 kfree(tg->rt_rq[i]);
158 if (tg->rt_se)
159 kfree(tg->rt_se[i]);
160 }
161
162 kfree(tg->rt_rq);
163 kfree(tg->rt_se);
164}
165
166void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
167 struct sched_rt_entity *rt_se, int cpu,
168 struct sched_rt_entity *parent)
169{
170 struct rq *rq = cpu_rq(cpu);
171
172 rt_rq->highest_prio.curr = MAX_RT_PRIO;
173 rt_rq->rt_nr_boosted = 0;
174 rt_rq->rq = rq;
175 rt_rq->tg = tg;
176
177 tg->rt_rq[cpu] = rt_rq;
178 tg->rt_se[cpu] = rt_se;
179
180 if (!rt_se)
181 return;
182
183 if (!parent)
184 rt_se->rt_rq = &rq->rt;
185 else
186 rt_se->rt_rq = parent->my_q;
187
188 rt_se->my_q = rt_rq;
189 rt_se->parent = parent;
190 INIT_LIST_HEAD(&rt_se->run_list);
191}
192
193int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
194{
195 struct rt_rq *rt_rq;
196 struct sched_rt_entity *rt_se;
197 int i;
198
199 tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
200 if (!tg->rt_rq)
201 goto err;
202 tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
203 if (!tg->rt_se)
204 goto err;
205
206 init_rt_bandwidth(&tg->rt_bandwidth,
207 ktime_to_ns(def_rt_bandwidth.rt_period), 0);
208
209 for_each_possible_cpu(i) {
210 rt_rq = kzalloc_node(sizeof(struct rt_rq),
211 GFP_KERNEL, cpu_to_node(i));
212 if (!rt_rq)
213 goto err;
214
215 rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
216 GFP_KERNEL, cpu_to_node(i));
217 if (!rt_se)
218 goto err_free_rq;
219
220 init_rt_rq(rt_rq);
221 rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
222 init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);
223 }
224
225 return 1;
226
227err_free_rq:
228 kfree(rt_rq);
229err:
230 return 0;
231}
232
233#else
234
235#define rt_entity_is_task(rt_se) (1)
236
237static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
238{
239 return container_of(rt_se, struct task_struct, rt);
240}
241
242static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
243{
244 return container_of(rt_rq, struct rq, rt);
245}
246
247static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
248{
249 struct task_struct *p = rt_task_of(rt_se);
250
251 return task_rq(p);
252}
253
254static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
255{
256 struct rq *rq = rq_of_rt_se(rt_se);
257
258 return &rq->rt;
259}
260
261void free_rt_sched_group(struct task_group *tg) { }
262
263int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
264{
265 return 1;
266}
267#endif
268
269#ifdef CONFIG_SMP
270
271static void pull_rt_task(struct rq *this_rq);
272
273static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
274{
275
276 return rq->rt.highest_prio.curr > prev->prio;
277}
278
279static inline int rt_overloaded(struct rq *rq)
280{
281 return atomic_read(&rq->rd->rto_count);
282}
283
284static inline void rt_set_overload(struct rq *rq)
285{
286 if (!rq->online)
287 return;
288
289 cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);
290
291
292
293
294
295
296
297
298
299 smp_wmb();
300 atomic_inc(&rq->rd->rto_count);
301}
302
303static inline void rt_clear_overload(struct rq *rq)
304{
305 if (!rq->online)
306 return;
307
308
309 atomic_dec(&rq->rd->rto_count);
310 cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
311}
312
313static void update_rt_migration(struct rt_rq *rt_rq)
314{
315 if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) {
316 if (!rt_rq->overloaded) {
317 rt_set_overload(rq_of_rt_rq(rt_rq));
318 rt_rq->overloaded = 1;
319 }
320 } else if (rt_rq->overloaded) {
321 rt_clear_overload(rq_of_rt_rq(rt_rq));
322 rt_rq->overloaded = 0;
323 }
324}
325
326static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
327{
328 struct task_struct *p;
329
330 if (!rt_entity_is_task(rt_se))
331 return;
332
333 p = rt_task_of(rt_se);
334 rt_rq = &rq_of_rt_rq(rt_rq)->rt;
335
336 rt_rq->rt_nr_total++;
337 if (p->nr_cpus_allowed > 1)
338 rt_rq->rt_nr_migratory++;
339
340 update_rt_migration(rt_rq);
341}
342
343static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
344{
345 struct task_struct *p;
346
347 if (!rt_entity_is_task(rt_se))
348 return;
349
350 p = rt_task_of(rt_se);
351 rt_rq = &rq_of_rt_rq(rt_rq)->rt;
352
353 rt_rq->rt_nr_total--;
354 if (p->nr_cpus_allowed > 1)
355 rt_rq->rt_nr_migratory--;
356
357 update_rt_migration(rt_rq);
358}
359
360static inline int has_pushable_tasks(struct rq *rq)
361{
362 return !plist_head_empty(&rq->rt.pushable_tasks);
363}
364
365static DEFINE_PER_CPU(struct callback_head, rt_push_head);
366static DEFINE_PER_CPU(struct callback_head, rt_pull_head);
367
368static void push_rt_tasks(struct rq *);
369static void pull_rt_task(struct rq *);
370
371static inline void queue_push_tasks(struct rq *rq)
372{
373 if (!has_pushable_tasks(rq))
374 return;
375
376 queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks);
377}
378
379static inline void queue_pull_task(struct rq *rq)
380{
381 queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task);
382}
383
384static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
385{
386 plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
387 plist_node_init(&p->pushable_tasks, p->prio);
388 plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks);
389
390
391 if (p->prio < rq->rt.highest_prio.next)
392 rq->rt.highest_prio.next = p->prio;
393}
394
395static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
396{
397 plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
398
399
400 if (has_pushable_tasks(rq)) {
401 p = plist_first_entry(&rq->rt.pushable_tasks,
402 struct task_struct, pushable_tasks);
403 rq->rt.highest_prio.next = p->prio;
404 } else
405 rq->rt.highest_prio.next = MAX_RT_PRIO;
406}
407
408#else
409
410static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
411{
412}
413
414static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
415{
416}
417
418static inline
419void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
420{
421}
422
423static inline
424void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
425{
426}
427
428static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev)
429{
430 return false;
431}
432
433static inline void pull_rt_task(struct rq *this_rq)
434{
435}
436
437static inline void queue_push_tasks(struct rq *rq)
438{
439}
440#endif
441
442static void enqueue_top_rt_rq(struct rt_rq *rt_rq);
443static void dequeue_top_rt_rq(struct rt_rq *rt_rq);
444
445static inline int on_rt_rq(struct sched_rt_entity *rt_se)
446{
447 return rt_se->on_rq;
448}
449
450#ifdef CONFIG_RT_GROUP_SCHED
451
452static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
453{
454 if (!rt_rq->tg)
455 return RUNTIME_INF;
456
457 return rt_rq->rt_runtime;
458}
459
460static inline u64 sched_rt_period(struct rt_rq *rt_rq)
461{
462 return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);
463}
464
465typedef struct task_group *rt_rq_iter_t;
466
467static inline struct task_group *next_task_group(struct task_group *tg)
468{
469 do {
470 tg = list_entry_rcu(tg->list.next,
471 typeof(struct task_group), list);
472 } while (&tg->list != &task_groups && task_group_is_autogroup(tg));
473
474 if (&tg->list == &task_groups)
475 tg = NULL;
476
477 return tg;
478}
479
480#define for_each_rt_rq(rt_rq, iter, rq) \
481 for (iter = container_of(&task_groups, typeof(*iter), list); \
482 (iter = next_task_group(iter)) && \
483 (rt_rq = iter->rt_rq[cpu_of(rq)]);)
484
485#define for_each_sched_rt_entity(rt_se) \
486 for (; rt_se; rt_se = rt_se->parent)
487
488static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
489{
490 return rt_se->my_q;
491}
492
493static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
494static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
495
496static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
497{
498 struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
499 struct rq *rq = rq_of_rt_rq(rt_rq);
500 struct sched_rt_entity *rt_se;
501
502 int cpu = cpu_of(rq);
503
504 rt_se = rt_rq->tg->rt_se[cpu];
505
506 if (rt_rq->rt_nr_running) {
507 if (!rt_se)
508 enqueue_top_rt_rq(rt_rq);
509 else if (!on_rt_rq(rt_se))
510 enqueue_rt_entity(rt_se, 0);
511
512 if (rt_rq->highest_prio.curr < curr->prio)
513 resched_curr(rq);
514 }
515}
516
517static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
518{
519 struct sched_rt_entity *rt_se;
520 int cpu = cpu_of(rq_of_rt_rq(rt_rq));
521
522 rt_se = rt_rq->tg->rt_se[cpu];
523
524 if (!rt_se)
525 dequeue_top_rt_rq(rt_rq);
526 else if (on_rt_rq(rt_se))
527 dequeue_rt_entity(rt_se, 0);
528}
529
530static inline int rt_rq_throttled(struct rt_rq *rt_rq)
531{
532 return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
533}
534
535static int rt_se_boosted(struct sched_rt_entity *rt_se)
536{
537 struct rt_rq *rt_rq = group_rt_rq(rt_se);
538 struct task_struct *p;
539
540 if (rt_rq)
541 return !!rt_rq->rt_nr_boosted;
542
543 p = rt_task_of(rt_se);
544 return p->prio != p->normal_prio;
545}
546
547#ifdef CONFIG_SMP
548static inline const struct cpumask *sched_rt_period_mask(void)
549{
550 return this_rq()->rd->span;
551}
552#else
553static inline const struct cpumask *sched_rt_period_mask(void)
554{
555 return cpu_online_mask;
556}
557#endif
558
559static inline
560struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
561{
562 return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
563}
564
565static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
566{
567 return &rt_rq->tg->rt_bandwidth;
568}
569
570#else
571
572static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
573{
574 return rt_rq->rt_runtime;
575}
576
577static inline u64 sched_rt_period(struct rt_rq *rt_rq)
578{
579 return ktime_to_ns(def_rt_bandwidth.rt_period);
580}
581
582typedef struct rt_rq *rt_rq_iter_t;
583
584#define for_each_rt_rq(rt_rq, iter, rq) \
585 for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
586
587#define for_each_sched_rt_entity(rt_se) \
588 for (; rt_se; rt_se = NULL)
589
590static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
591{
592 return NULL;
593}
594
595static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
596{
597 struct rq *rq = rq_of_rt_rq(rt_rq);
598
599 if (!rt_rq->rt_nr_running)
600 return;
601
602 enqueue_top_rt_rq(rt_rq);
603 resched_curr(rq);
604}
605
606static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
607{
608 dequeue_top_rt_rq(rt_rq);
609}
610
611static inline int rt_rq_throttled(struct rt_rq *rt_rq)
612{
613 return rt_rq->rt_throttled;
614}
615
616static inline const struct cpumask *sched_rt_period_mask(void)
617{
618 return cpu_online_mask;
619}
620
621static inline
622struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
623{
624 return &cpu_rq(cpu)->rt;
625}
626
627static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
628{
629 return &def_rt_bandwidth;
630}
631
632#endif
633
634bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
635{
636 struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
637
638 return (hrtimer_active(&rt_b->rt_period_timer) ||
639 rt_rq->rt_time < rt_b->rt_runtime);
640}
641
642#ifdef CONFIG_SMP
643
644
645
646static void do_balance_runtime(struct rt_rq *rt_rq)
647{
648 struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
649 struct root_domain *rd = rq_of_rt_rq(rt_rq)->rd;
650 int i, weight;
651 u64 rt_period;
652
653 weight = cpumask_weight(rd->span);
654
655 raw_spin_lock(&rt_b->rt_runtime_lock);
656 rt_period = ktime_to_ns(rt_b->rt_period);
657 for_each_cpu(i, rd->span) {
658 struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
659 s64 diff;
660
661 if (iter == rt_rq)
662 continue;
663
664 raw_spin_lock(&iter->rt_runtime_lock);
665
666
667
668
669
670 if (iter->rt_runtime == RUNTIME_INF)
671 goto next;
672
673
674
675
676
677 diff = iter->rt_runtime - iter->rt_time;
678 if (diff > 0) {
679 diff = div_u64((u64)diff, weight);
680 if (rt_rq->rt_runtime + diff > rt_period)
681 diff = rt_period - rt_rq->rt_runtime;
682 iter->rt_runtime -= diff;
683 rt_rq->rt_runtime += diff;
684 if (rt_rq->rt_runtime == rt_period) {
685 raw_spin_unlock(&iter->rt_runtime_lock);
686 break;
687 }
688 }
689next:
690 raw_spin_unlock(&iter->rt_runtime_lock);
691 }
692 raw_spin_unlock(&rt_b->rt_runtime_lock);
693}
694
695
696
697
698static void __disable_runtime(struct rq *rq)
699{
700 struct root_domain *rd = rq->rd;
701 rt_rq_iter_t iter;
702 struct rt_rq *rt_rq;
703
704 if (unlikely(!scheduler_running))
705 return;
706
707 for_each_rt_rq(rt_rq, iter, rq) {
708 struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
709 s64 want;
710 int i;
711
712 raw_spin_lock(&rt_b->rt_runtime_lock);
713 raw_spin_lock(&rt_rq->rt_runtime_lock);
714
715
716
717
718
719 if (rt_rq->rt_runtime == RUNTIME_INF ||
720 rt_rq->rt_runtime == rt_b->rt_runtime)
721 goto balanced;
722 raw_spin_unlock(&rt_rq->rt_runtime_lock);
723
724
725
726
727
728
729 want = rt_b->rt_runtime - rt_rq->rt_runtime;
730
731
732
733
734 for_each_cpu(i, rd->span) {
735 struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
736 s64 diff;
737
738
739
740
741 if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
742 continue;
743
744 raw_spin_lock(&iter->rt_runtime_lock);
745 if (want > 0) {
746 diff = min_t(s64, iter->rt_runtime, want);
747 iter->rt_runtime -= diff;
748 want -= diff;
749 } else {
750 iter->rt_runtime -= want;
751 want -= want;
752 }
753 raw_spin_unlock(&iter->rt_runtime_lock);
754
755 if (!want)
756 break;
757 }
758
759 raw_spin_lock(&rt_rq->rt_runtime_lock);
760
761
762
763
764 BUG_ON(want);
765balanced:
766
767
768
769
770 rt_rq->rt_runtime = RUNTIME_INF;
771 rt_rq->rt_throttled = 0;
772 raw_spin_unlock(&rt_rq->rt_runtime_lock);
773 raw_spin_unlock(&rt_b->rt_runtime_lock);
774
775
776 sched_rt_rq_enqueue(rt_rq);
777 }
778}
779
780static void __enable_runtime(struct rq *rq)
781{
782 rt_rq_iter_t iter;
783 struct rt_rq *rt_rq;
784
785 if (unlikely(!scheduler_running))
786 return;
787
788
789
790
791 for_each_rt_rq(rt_rq, iter, rq) {
792 struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
793
794 raw_spin_lock(&rt_b->rt_runtime_lock);
795 raw_spin_lock(&rt_rq->rt_runtime_lock);
796 rt_rq->rt_runtime = rt_b->rt_runtime;
797 rt_rq->rt_time = 0;
798 rt_rq->rt_throttled = 0;
799 raw_spin_unlock(&rt_rq->rt_runtime_lock);
800 raw_spin_unlock(&rt_b->rt_runtime_lock);
801 }
802}
803
804static void balance_runtime(struct rt_rq *rt_rq)
805{
806 if (!sched_feat(RT_RUNTIME_SHARE))
807 return;
808
809 if (rt_rq->rt_time > rt_rq->rt_runtime) {
810 raw_spin_unlock(&rt_rq->rt_runtime_lock);
811 do_balance_runtime(rt_rq);
812 raw_spin_lock(&rt_rq->rt_runtime_lock);
813 }
814}
815#else
816static inline void balance_runtime(struct rt_rq *rt_rq) {}
817#endif
818
819static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
820{
821 int i, idle = 1, throttled = 0;
822 const struct cpumask *span;
823
824 span = sched_rt_period_mask();
825#ifdef CONFIG_RT_GROUP_SCHED
826
827
828
829
830
831
832
833
834
835 if (rt_b == &root_task_group.rt_bandwidth)
836 span = cpu_online_mask;
837#endif
838 for_each_cpu(i, span) {
839 int enqueue = 0;
840 struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
841 struct rq *rq = rq_of_rt_rq(rt_rq);
842
843 raw_spin_lock(&rq->lock);
844 if (rt_rq->rt_time) {
845 u64 runtime;
846
847 raw_spin_lock(&rt_rq->rt_runtime_lock);
848 if (rt_rq->rt_throttled)
849 balance_runtime(rt_rq);
850 runtime = rt_rq->rt_runtime;
851 rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
852 if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
853 rt_rq->rt_throttled = 0;
854 enqueue = 1;
855
856
857
858
859
860
861
862
863 if (rt_rq->rt_nr_running && rq->curr == rq->idle)
864 rq_clock_skip_update(rq, false);
865 }
866 if (rt_rq->rt_time || rt_rq->rt_nr_running)
867 idle = 0;
868 raw_spin_unlock(&rt_rq->rt_runtime_lock);
869 } else if (rt_rq->rt_nr_running) {
870 idle = 0;
871 if (!rt_rq_throttled(rt_rq))
872 enqueue = 1;
873 }
874 if (rt_rq->rt_throttled)
875 throttled = 1;
876
877 if (enqueue)
878 sched_rt_rq_enqueue(rt_rq);
879 raw_spin_unlock(&rq->lock);
880 }
881
882 if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))
883 return 1;
884
885 return idle;
886}
887
888static inline int rt_se_prio(struct sched_rt_entity *rt_se)
889{
890#ifdef CONFIG_RT_GROUP_SCHED
891 struct rt_rq *rt_rq = group_rt_rq(rt_se);
892
893 if (rt_rq)
894 return rt_rq->highest_prio.curr;
895#endif
896
897 return rt_task_of(rt_se)->prio;
898}
899
900static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
901{
902 u64 runtime = sched_rt_runtime(rt_rq);
903
904 if (rt_rq->rt_throttled)
905 return rt_rq_throttled(rt_rq);
906
907 if (runtime >= sched_rt_period(rt_rq))
908 return 0;
909
910 balance_runtime(rt_rq);
911 runtime = sched_rt_runtime(rt_rq);
912 if (runtime == RUNTIME_INF)
913 return 0;
914
915 if (rt_rq->rt_time > runtime) {
916 struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
917
918
919
920
921
922 if (likely(rt_b->rt_runtime)) {
923 rt_rq->rt_throttled = 1;
924 printk_deferred_once("sched: RT throttling activated\n");
925 } else {
926
927
928
929
930
931 rt_rq->rt_time = 0;
932 }
933
934 if (rt_rq_throttled(rt_rq)) {
935 sched_rt_rq_dequeue(rt_rq);
936 return 1;
937 }
938 }
939
940 return 0;
941}
942
943
944
945
946
947static void update_curr_rt(struct rq *rq)
948{
949 struct task_struct *curr = rq->curr;
950 struct sched_rt_entity *rt_se = &curr->rt;
951 u64 delta_exec;
952
953 if (curr->sched_class != &rt_sched_class)
954 return;
955
956
957 if (cpu_of(rq) == smp_processor_id())
958 cpufreq_trigger_update(rq_clock(rq));
959
960 delta_exec = rq_clock_task(rq) - curr->se.exec_start;
961 if (unlikely((s64)delta_exec <= 0))
962 return;
963
964 schedstat_set(curr->se.statistics.exec_max,
965 max(curr->se.statistics.exec_max, delta_exec));
966
967 curr->se.sum_exec_runtime += delta_exec;
968 account_group_exec_runtime(curr, delta_exec);
969
970 curr->se.exec_start = rq_clock_task(rq);
971 cpuacct_charge(curr, delta_exec);
972
973 sched_rt_avg_update(rq, delta_exec);
974
975 if (!rt_bandwidth_enabled())
976 return;
977
978 for_each_sched_rt_entity(rt_se) {
979 struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
980
981 if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
982 raw_spin_lock(&rt_rq->rt_runtime_lock);
983 rt_rq->rt_time += delta_exec;
984 if (sched_rt_runtime_exceeded(rt_rq))
985 resched_curr(rq);
986 raw_spin_unlock(&rt_rq->rt_runtime_lock);
987 }
988 }
989}
990
991static void
992dequeue_top_rt_rq(struct rt_rq *rt_rq)
993{
994 struct rq *rq = rq_of_rt_rq(rt_rq);
995
996 BUG_ON(&rq->rt != rt_rq);
997
998 if (!rt_rq->rt_queued)
999 return;
1000
1001 BUG_ON(!rq->nr_running);
1002
1003 sub_nr_running(rq, rt_rq->rt_nr_running);
1004 rt_rq->rt_queued = 0;
1005}
1006
1007static void
1008enqueue_top_rt_rq(struct rt_rq *rt_rq)
1009{
1010 struct rq *rq = rq_of_rt_rq(rt_rq);
1011
1012 BUG_ON(&rq->rt != rt_rq);
1013
1014 if (rt_rq->rt_queued)
1015 return;
1016 if (rt_rq_throttled(rt_rq) || !rt_rq->rt_nr_running)
1017 return;
1018
1019 add_nr_running(rq, rt_rq->rt_nr_running);
1020 rt_rq->rt_queued = 1;
1021}
1022
1023#if defined CONFIG_SMP
1024
1025static void
1026inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
1027{
1028 struct rq *rq = rq_of_rt_rq(rt_rq);
1029
1030#ifdef CONFIG_RT_GROUP_SCHED
1031
1032
1033
1034 if (&rq->rt != rt_rq)
1035 return;
1036#endif
1037 if (rq->online && prio < prev_prio)
1038 cpupri_set(&rq->rd->cpupri, rq->cpu, prio);
1039}
1040
1041static void
1042dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
1043{
1044 struct rq *rq = rq_of_rt_rq(rt_rq);
1045
1046#ifdef CONFIG_RT_GROUP_SCHED
1047
1048
1049
1050 if (&rq->rt != rt_rq)
1051 return;
1052#endif
1053 if (rq->online && rt_rq->highest_prio.curr != prev_prio)
1054 cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
1055}
1056
1057#else
1058
1059static inline
1060void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
1061static inline
1062void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
1063
1064#endif
1065
1066#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
1067static void
1068inc_rt_prio(struct rt_rq *rt_rq, int prio)
1069{
1070 int prev_prio = rt_rq->highest_prio.curr;
1071
1072 if (prio < prev_prio)
1073 rt_rq->highest_prio.curr = prio;
1074
1075 inc_rt_prio_smp(rt_rq, prio, prev_prio);
1076}
1077
1078static void
1079dec_rt_prio(struct rt_rq *rt_rq, int prio)
1080{
1081 int prev_prio = rt_rq->highest_prio.curr;
1082
1083 if (rt_rq->rt_nr_running) {
1084
1085 WARN_ON(prio < prev_prio);
1086
1087
1088
1089
1090
1091 if (prio == prev_prio) {
1092 struct rt_prio_array *array = &rt_rq->active;
1093
1094 rt_rq->highest_prio.curr =
1095 sched_find_first_bit(array->bitmap);
1096 }
1097
1098 } else
1099 rt_rq->highest_prio.curr = MAX_RT_PRIO;
1100
1101 dec_rt_prio_smp(rt_rq, prio, prev_prio);
1102}
1103
1104#else
1105
1106static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
1107static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
1108
1109#endif
1110
1111#ifdef CONFIG_RT_GROUP_SCHED
1112
1113static void
1114inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
1115{
1116 if (rt_se_boosted(rt_se))
1117 rt_rq->rt_nr_boosted++;
1118
1119 if (rt_rq->tg)
1120 start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
1121}
1122
1123static void
1124dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
1125{
1126 if (rt_se_boosted(rt_se))
1127 rt_rq->rt_nr_boosted--;
1128
1129 WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);
1130}
1131
1132#else
1133
1134static void
1135inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
1136{
1137 start_rt_bandwidth(&def_rt_bandwidth);
1138}
1139
1140static inline
1141void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
1142
1143#endif
1144
1145static inline
1146unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
1147{
1148 struct rt_rq *group_rq = group_rt_rq(rt_se);
1149
1150 if (group_rq)
1151 return group_rq->rt_nr_running;
1152 else
1153 return 1;
1154}
1155
1156static inline
1157unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se)
1158{
1159 struct rt_rq *group_rq = group_rt_rq(rt_se);
1160 struct task_struct *tsk;
1161
1162 if (group_rq)
1163 return group_rq->rr_nr_running;
1164
1165 tsk = rt_task_of(rt_se);
1166
1167 return (tsk->policy == SCHED_RR) ? 1 : 0;
1168}
1169
1170static inline
1171void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
1172{
1173 int prio = rt_se_prio(rt_se);
1174
1175 WARN_ON(!rt_prio(prio));
1176 rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
1177 rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se);
1178
1179 inc_rt_prio(rt_rq, prio);
1180 inc_rt_migration(rt_se, rt_rq);
1181 inc_rt_group(rt_se, rt_rq);
1182}
1183
1184static inline
1185void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
1186{
1187 WARN_ON(!rt_prio(rt_se_prio(rt_se)));
1188 WARN_ON(!rt_rq->rt_nr_running);
1189 rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
1190 rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se);
1191
1192 dec_rt_prio(rt_rq, rt_se_prio(rt_se));
1193 dec_rt_migration(rt_se, rt_rq);
1194 dec_rt_group(rt_se, rt_rq);
1195}
1196
1197
1198
1199
1200
1201
1202static inline bool move_entity(unsigned int flags)
1203{
1204 if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE)
1205 return false;
1206
1207 return true;
1208}
1209
1210static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array)
1211{
1212 list_del_init(&rt_se->run_list);
1213
1214 if (list_empty(array->queue + rt_se_prio(rt_se)))
1215 __clear_bit(rt_se_prio(rt_se), array->bitmap);
1216
1217 rt_se->on_list = 0;
1218}
1219
1220static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
1221{
1222 struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
1223 struct rt_prio_array *array = &rt_rq->active;
1224 struct rt_rq *group_rq = group_rt_rq(rt_se);
1225 struct list_head *queue = array->queue + rt_se_prio(rt_se);
1226
1227
1228
1229
1230
1231
1232
1233 if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) {
1234 if (rt_se->on_list)
1235 __delist_rt_entity(rt_se, array);
1236 return;
1237 }
1238
1239 if (move_entity(flags)) {
1240 WARN_ON_ONCE(rt_se->on_list);
1241 if (flags & ENQUEUE_HEAD)
1242 list_add(&rt_se->run_list, queue);
1243 else
1244 list_add_tail(&rt_se->run_list, queue);
1245
1246 __set_bit(rt_se_prio(rt_se), array->bitmap);
1247 rt_se->on_list = 1;
1248 }
1249 rt_se->on_rq = 1;
1250
1251 inc_rt_tasks(rt_se, rt_rq);
1252}
1253
1254static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
1255{
1256 struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
1257 struct rt_prio_array *array = &rt_rq->active;
1258
1259 if (move_entity(flags)) {
1260 WARN_ON_ONCE(!rt_se->on_list);
1261 __delist_rt_entity(rt_se, array);
1262 }
1263 rt_se->on_rq = 0;
1264
1265 dec_rt_tasks(rt_se, rt_rq);
1266}
1267
1268
1269
1270
1271
1272static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags)
1273{
1274 struct sched_rt_entity *back = NULL;
1275
1276 for_each_sched_rt_entity(rt_se) {
1277 rt_se->back = back;
1278 back = rt_se;
1279 }
1280
1281 dequeue_top_rt_rq(rt_rq_of_se(back));
1282
1283 for (rt_se = back; rt_se; rt_se = rt_se->back) {
1284 if (on_rt_rq(rt_se))
1285 __dequeue_rt_entity(rt_se, flags);
1286 }
1287}
1288
1289static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
1290{
1291 struct rq *rq = rq_of_rt_se(rt_se);
1292
1293 dequeue_rt_stack(rt_se, flags);
1294 for_each_sched_rt_entity(rt_se)
1295 __enqueue_rt_entity(rt_se, flags);
1296 enqueue_top_rt_rq(&rq->rt);
1297}
1298
1299static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
1300{
1301 struct rq *rq = rq_of_rt_se(rt_se);
1302
1303 dequeue_rt_stack(rt_se, flags);
1304
1305 for_each_sched_rt_entity(rt_se) {
1306 struct rt_rq *rt_rq = group_rt_rq(rt_se);
1307
1308 if (rt_rq && rt_rq->rt_nr_running)
1309 __enqueue_rt_entity(rt_se, flags);
1310 }
1311 enqueue_top_rt_rq(&rq->rt);
1312}
1313
1314
1315
1316
1317static void
1318enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
1319{
1320 struct sched_rt_entity *rt_se = &p->rt;
1321
1322 if (flags & ENQUEUE_WAKEUP)
1323 rt_se->timeout = 0;
1324
1325 enqueue_rt_entity(rt_se, flags);
1326
1327 if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
1328 enqueue_pushable_task(rq, p);
1329}
1330
1331static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
1332{
1333 struct sched_rt_entity *rt_se = &p->rt;
1334
1335 update_curr_rt(rq);
1336 dequeue_rt_entity(rt_se, flags);
1337
1338 dequeue_pushable_task(rq, p);
1339}
1340
1341
1342
1343
1344
1345static void
1346requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)
1347{
1348 if (on_rt_rq(rt_se)) {
1349 struct rt_prio_array *array = &rt_rq->active;
1350 struct list_head *queue = array->queue + rt_se_prio(rt_se);
1351
1352 if (head)
1353 list_move(&rt_se->run_list, queue);
1354 else
1355 list_move_tail(&rt_se->run_list, queue);
1356 }
1357}
1358
1359static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
1360{
1361 struct sched_rt_entity *rt_se = &p->rt;
1362 struct rt_rq *rt_rq;
1363
1364 for_each_sched_rt_entity(rt_se) {
1365 rt_rq = rt_rq_of_se(rt_se);
1366 requeue_rt_entity(rt_rq, rt_se, head);
1367 }
1368}
1369
1370static void yield_task_rt(struct rq *rq)
1371{
1372 requeue_task_rt(rq, rq->curr, 0);
1373}
1374
1375#ifdef CONFIG_SMP
1376static int find_lowest_rq(struct task_struct *task);
1377
1378static int
1379select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
1380{
1381 struct task_struct *curr;
1382 struct rq *rq;
1383
1384
1385 if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
1386 goto out;
1387
1388 rq = cpu_rq(cpu);
1389
1390 rcu_read_lock();
1391 curr = READ_ONCE(rq->curr);
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415 if (curr && unlikely(rt_task(curr)) &&
1416 (curr->nr_cpus_allowed < 2 ||
1417 curr->prio <= p->prio)) {
1418 int target = find_lowest_rq(p);
1419
1420
1421
1422
1423
1424 if (target != -1 &&
1425 p->prio < cpu_rq(target)->rt.highest_prio.curr)
1426 cpu = target;
1427 }
1428 rcu_read_unlock();
1429
1430out:
1431 return cpu;
1432}
1433
1434static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
1435{
1436
1437
1438
1439
1440 if (rq->curr->nr_cpus_allowed == 1 ||
1441 !cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
1442 return;
1443
1444
1445
1446
1447
1448 if (p->nr_cpus_allowed != 1
1449 && cpupri_find(&rq->rd->cpupri, p, NULL))
1450 return;
1451
1452
1453
1454
1455
1456
1457 requeue_task_rt(rq, p, 1);
1458 resched_curr(rq);
1459}
1460
1461#endif
1462
1463
1464
1465
1466static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
1467{
1468 if (p->prio < rq->curr->prio) {
1469 resched_curr(rq);
1470 return;
1471 }
1472
1473#ifdef CONFIG_SMP
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486 if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))
1487 check_preempt_equal_prio(rq, p);
1488#endif
1489}
1490
1491static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
1492 struct rt_rq *rt_rq)
1493{
1494 struct rt_prio_array *array = &rt_rq->active;
1495 struct sched_rt_entity *next = NULL;
1496 struct list_head *queue;
1497 int idx;
1498
1499 idx = sched_find_first_bit(array->bitmap);
1500 BUG_ON(idx >= MAX_RT_PRIO);
1501
1502 queue = array->queue + idx;
1503 next = list_entry(queue->next, struct sched_rt_entity, run_list);
1504
1505 return next;
1506}
1507
1508static struct task_struct *_pick_next_task_rt(struct rq *rq)
1509{
1510 struct sched_rt_entity *rt_se;
1511 struct task_struct *p;
1512 struct rt_rq *rt_rq = &rq->rt;
1513
1514 do {
1515 rt_se = pick_next_rt_entity(rq, rt_rq);
1516 BUG_ON(!rt_se);
1517 rt_rq = group_rt_rq(rt_se);
1518 } while (rt_rq);
1519
1520 p = rt_task_of(rt_se);
1521 p->se.exec_start = rq_clock_task(rq);
1522
1523 return p;
1524}
1525
1526static struct task_struct *
1527pick_next_task_rt(struct rq *rq, struct task_struct *prev)
1528{
1529 struct task_struct *p;
1530 struct rt_rq *rt_rq = &rq->rt;
1531
1532 if (need_pull_rt_task(rq, prev)) {
1533
1534
1535
1536
1537
1538
1539 lockdep_unpin_lock(&rq->lock);
1540 pull_rt_task(rq);
1541 lockdep_pin_lock(&rq->lock);
1542
1543
1544
1545
1546
1547 if (unlikely((rq->stop && task_on_rq_queued(rq->stop)) ||
1548 rq->dl.dl_nr_running))
1549 return RETRY_TASK;
1550 }
1551
1552
1553
1554
1555
1556 if (prev->sched_class == &rt_sched_class)
1557 update_curr_rt(rq);
1558
1559 if (!rt_rq->rt_queued)
1560 return NULL;
1561
1562 put_prev_task(rq, prev);
1563
1564 p = _pick_next_task_rt(rq);
1565
1566
1567 dequeue_pushable_task(rq, p);
1568
1569 queue_push_tasks(rq);
1570
1571 return p;
1572}
1573
1574static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
1575{
1576 update_curr_rt(rq);
1577
1578
1579
1580
1581
1582 if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)
1583 enqueue_pushable_task(rq, p);
1584}
1585
1586#ifdef CONFIG_SMP
1587
1588
1589#define RT_MAX_TRIES 3
1590
1591static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
1592{
1593 if (!task_running(rq, p) &&
1594 cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
1595 return 1;
1596 return 0;
1597}
1598
1599
1600
1601
1602
1603static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu)
1604{
1605 struct plist_head *head = &rq->rt.pushable_tasks;
1606 struct task_struct *p;
1607
1608 if (!has_pushable_tasks(rq))
1609 return NULL;
1610
1611 plist_for_each_entry(p, head, pushable_tasks) {
1612 if (pick_rt_task(rq, p, cpu))
1613 return p;
1614 }
1615
1616 return NULL;
1617}
1618
1619static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
1620
1621static int find_lowest_rq(struct task_struct *task)
1622{
1623 struct sched_domain *sd;
1624 struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask);
1625 int this_cpu = smp_processor_id();
1626 int cpu = task_cpu(task);
1627
1628
1629 if (unlikely(!lowest_mask))
1630 return -1;
1631
1632 if (task->nr_cpus_allowed == 1)
1633 return -1;
1634
1635 if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
1636 return -1;
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646 if (cpumask_test_cpu(cpu, lowest_mask))
1647 return cpu;
1648
1649
1650
1651
1652
1653 if (!cpumask_test_cpu(this_cpu, lowest_mask))
1654 this_cpu = -1;
1655
1656 rcu_read_lock();
1657 for_each_domain(cpu, sd) {
1658 if (sd->flags & SD_WAKE_AFFINE) {
1659 int best_cpu;
1660
1661
1662
1663
1664
1665 if (this_cpu != -1 &&
1666 cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {
1667 rcu_read_unlock();
1668 return this_cpu;
1669 }
1670
1671 best_cpu = cpumask_first_and(lowest_mask,
1672 sched_domain_span(sd));
1673 if (best_cpu < nr_cpu_ids) {
1674 rcu_read_unlock();
1675 return best_cpu;
1676 }
1677 }
1678 }
1679 rcu_read_unlock();
1680
1681
1682
1683
1684
1685
1686 if (this_cpu != -1)
1687 return this_cpu;
1688
1689 cpu = cpumask_any(lowest_mask);
1690 if (cpu < nr_cpu_ids)
1691 return cpu;
1692 return -1;
1693}
1694
1695
1696static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
1697{
1698 struct rq *lowest_rq = NULL;
1699 int tries;
1700 int cpu;
1701
1702 for (tries = 0; tries < RT_MAX_TRIES; tries++) {
1703 cpu = find_lowest_rq(task);
1704
1705 if ((cpu == -1) || (cpu == rq->cpu))
1706 break;
1707
1708 lowest_rq = cpu_rq(cpu);
1709
1710 if (lowest_rq->rt.highest_prio.curr <= task->prio) {
1711
1712
1713
1714
1715
1716 lowest_rq = NULL;
1717 break;
1718 }
1719
1720
1721 if (double_lock_balance(rq, lowest_rq)) {
1722
1723
1724
1725
1726
1727
1728 if (unlikely(task_rq(task) != rq ||
1729 !cpumask_test_cpu(lowest_rq->cpu,
1730 tsk_cpus_allowed(task)) ||
1731 task_running(rq, task) ||
1732 !rt_task(task) ||
1733 !task_on_rq_queued(task))) {
1734
1735 double_unlock_balance(rq, lowest_rq);
1736 lowest_rq = NULL;
1737 break;
1738 }
1739 }
1740
1741
1742 if (lowest_rq->rt.highest_prio.curr > task->prio)
1743 break;
1744
1745
1746 double_unlock_balance(rq, lowest_rq);
1747 lowest_rq = NULL;
1748 }
1749
1750 return lowest_rq;
1751}
1752
1753static struct task_struct *pick_next_pushable_task(struct rq *rq)
1754{
1755 struct task_struct *p;
1756
1757 if (!has_pushable_tasks(rq))
1758 return NULL;
1759
1760 p = plist_first_entry(&rq->rt.pushable_tasks,
1761 struct task_struct, pushable_tasks);
1762
1763 BUG_ON(rq->cpu != task_cpu(p));
1764 BUG_ON(task_current(rq, p));
1765 BUG_ON(p->nr_cpus_allowed <= 1);
1766
1767 BUG_ON(!task_on_rq_queued(p));
1768 BUG_ON(!rt_task(p));
1769
1770 return p;
1771}
1772
1773
1774
1775
1776
1777
1778static int push_rt_task(struct rq *rq)
1779{
1780 struct task_struct *next_task;
1781 struct rq *lowest_rq;
1782 int ret = 0;
1783
1784 if (!rq->rt.overloaded)
1785 return 0;
1786
1787 next_task = pick_next_pushable_task(rq);
1788 if (!next_task)
1789 return 0;
1790
1791retry:
1792 if (unlikely(next_task == rq->curr)) {
1793 WARN_ON(1);
1794 return 0;
1795 }
1796
1797
1798
1799
1800
1801
1802 if (unlikely(next_task->prio < rq->curr->prio)) {
1803 resched_curr(rq);
1804 return 0;
1805 }
1806
1807
1808 get_task_struct(next_task);
1809
1810
1811 lowest_rq = find_lock_lowest_rq(next_task, rq);
1812 if (!lowest_rq) {
1813 struct task_struct *task;
1814
1815
1816
1817
1818
1819
1820
1821
1822 task = pick_next_pushable_task(rq);
1823 if (task_cpu(next_task) == rq->cpu && task == next_task) {
1824
1825
1826
1827
1828
1829
1830 goto out;
1831 }
1832
1833 if (!task)
1834
1835 goto out;
1836
1837
1838
1839
1840 put_task_struct(next_task);
1841 next_task = task;
1842 goto retry;
1843 }
1844
1845 deactivate_task(rq, next_task, 0);
1846 set_task_cpu(next_task, lowest_rq->cpu);
1847 activate_task(lowest_rq, next_task, 0);
1848 ret = 1;
1849
1850 resched_curr(lowest_rq);
1851
1852 double_unlock_balance(rq, lowest_rq);
1853
1854out:
1855 put_task_struct(next_task);
1856
1857 return ret;
1858}
1859
1860static void push_rt_tasks(struct rq *rq)
1861{
1862
1863 while (push_rt_task(rq))
1864 ;
1865}
1866
1867#ifdef HAVE_RT_PUSH_IPI
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877static int rto_next_cpu(struct rq *rq)
1878{
1879 int prev_cpu = rq->rt.push_cpu;
1880 int cpu;
1881
1882 cpu = cpumask_next(prev_cpu, rq->rd->rto_mask);
1883
1884
1885
1886
1887
1888
1889 if (prev_cpu < rq->cpu) {
1890 if (cpu >= rq->cpu)
1891 return nr_cpu_ids;
1892
1893 } else if (cpu >= nr_cpu_ids) {
1894
1895
1896
1897
1898
1899 cpu = cpumask_first(rq->rd->rto_mask);
1900 if (cpu >= rq->cpu)
1901 return nr_cpu_ids;
1902 }
1903 rq->rt.push_cpu = cpu;
1904
1905
1906 return cpu;
1907}
1908
1909static int find_next_push_cpu(struct rq *rq)
1910{
1911 struct rq *next_rq;
1912 int cpu;
1913
1914 while (1) {
1915 cpu = rto_next_cpu(rq);
1916 if (cpu >= nr_cpu_ids)
1917 break;
1918 next_rq = cpu_rq(cpu);
1919
1920
1921 if (next_rq->rt.highest_prio.next < rq->rt.highest_prio.curr)
1922 break;
1923 }
1924
1925 return cpu;
1926}
1927
1928#define RT_PUSH_IPI_EXECUTING 1
1929#define RT_PUSH_IPI_RESTART 2
1930
1931static void tell_cpu_to_push(struct rq *rq)
1932{
1933 int cpu;
1934
1935 if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) {
1936 raw_spin_lock(&rq->rt.push_lock);
1937
1938 if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) {
1939
1940
1941
1942
1943 rq->rt.push_flags |= RT_PUSH_IPI_RESTART;
1944 raw_spin_unlock(&rq->rt.push_lock);
1945 return;
1946 }
1947 raw_spin_unlock(&rq->rt.push_lock);
1948 }
1949
1950
1951
1952 rq->rt.push_cpu = rq->cpu;
1953 cpu = find_next_push_cpu(rq);
1954 if (cpu >= nr_cpu_ids)
1955 return;
1956
1957 rq->rt.push_flags = RT_PUSH_IPI_EXECUTING;
1958
1959 irq_work_queue_on(&rq->rt.push_work, cpu);
1960}
1961
1962
1963static void try_to_push_tasks(void *arg)
1964{
1965 struct rt_rq *rt_rq = arg;
1966 struct rq *rq, *src_rq;
1967 int this_cpu;
1968 int cpu;
1969
1970 this_cpu = rt_rq->push_cpu;
1971
1972
1973 BUG_ON(this_cpu != smp_processor_id());
1974
1975 rq = cpu_rq(this_cpu);
1976 src_rq = rq_of_rt_rq(rt_rq);
1977
1978again:
1979 if (has_pushable_tasks(rq)) {
1980 raw_spin_lock(&rq->lock);
1981 push_rt_task(rq);
1982 raw_spin_unlock(&rq->lock);
1983 }
1984
1985
1986 raw_spin_lock(&rt_rq->push_lock);
1987
1988
1989
1990
1991 if (rt_rq->push_flags & RT_PUSH_IPI_RESTART) {
1992 rt_rq->push_flags &= ~RT_PUSH_IPI_RESTART;
1993 rt_rq->push_cpu = src_rq->cpu;
1994 }
1995
1996 cpu = find_next_push_cpu(src_rq);
1997
1998 if (cpu >= nr_cpu_ids)
1999 rt_rq->push_flags &= ~RT_PUSH_IPI_EXECUTING;
2000 raw_spin_unlock(&rt_rq->push_lock);
2001
2002 if (cpu >= nr_cpu_ids)
2003 return;
2004
2005
2006
2007
2008
2009
2010 if (unlikely(cpu == rq->cpu))
2011 goto again;
2012
2013
2014 irq_work_queue_on(&rt_rq->push_work, cpu);
2015}
2016
2017static void push_irq_work_func(struct irq_work *work)
2018{
2019 struct rt_rq *rt_rq = container_of(work, struct rt_rq, push_work);
2020
2021 try_to_push_tasks(rt_rq);
2022}
2023#endif
2024
2025static void pull_rt_task(struct rq *this_rq)
2026{
2027 int this_cpu = this_rq->cpu, cpu;
2028 bool resched = false;
2029 struct task_struct *p;
2030 struct rq *src_rq;
2031
2032 if (likely(!rt_overloaded(this_rq)))
2033 return;
2034
2035
2036
2037
2038
2039 smp_rmb();
2040
2041#ifdef HAVE_RT_PUSH_IPI
2042 if (sched_feat(RT_PUSH_IPI)) {
2043 tell_cpu_to_push(this_rq);
2044 return;
2045 }
2046#endif
2047
2048 for_each_cpu(cpu, this_rq->rd->rto_mask) {
2049 if (this_cpu == cpu)
2050 continue;
2051
2052 src_rq = cpu_rq(cpu);
2053
2054
2055
2056
2057
2058
2059
2060
2061 if (src_rq->rt.highest_prio.next >=
2062 this_rq->rt.highest_prio.curr)
2063 continue;
2064
2065
2066
2067
2068
2069
2070 double_lock_balance(this_rq, src_rq);
2071
2072
2073
2074
2075
2076 p = pick_highest_pushable_task(src_rq, this_cpu);
2077
2078
2079
2080
2081
2082 if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
2083 WARN_ON(p == src_rq->curr);
2084 WARN_ON(!task_on_rq_queued(p));
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094 if (p->prio < src_rq->curr->prio)
2095 goto skip;
2096
2097 resched = true;
2098
2099 deactivate_task(src_rq, p, 0);
2100 set_task_cpu(p, this_cpu);
2101 activate_task(this_rq, p, 0);
2102
2103
2104
2105
2106
2107
2108 }
2109skip:
2110 double_unlock_balance(this_rq, src_rq);
2111 }
2112
2113 if (resched)
2114 resched_curr(this_rq);
2115}
2116
2117
2118
2119
2120
2121static void task_woken_rt(struct rq *rq, struct task_struct *p)
2122{
2123 if (!task_running(rq, p) &&
2124 !test_tsk_need_resched(rq->curr) &&
2125 p->nr_cpus_allowed > 1 &&
2126 (dl_task(rq->curr) || rt_task(rq->curr)) &&
2127 (rq->curr->nr_cpus_allowed < 2 ||
2128 rq->curr->prio <= p->prio))
2129 push_rt_tasks(rq);
2130}
2131
2132
2133static void rq_online_rt(struct rq *rq)
2134{
2135 if (rq->rt.overloaded)
2136 rt_set_overload(rq);
2137
2138 __enable_runtime(rq);
2139
2140 cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);
2141}
2142
2143
2144static void rq_offline_rt(struct rq *rq)
2145{
2146 if (rq->rt.overloaded)
2147 rt_clear_overload(rq);
2148
2149 __disable_runtime(rq);
2150
2151 cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
2152}
2153
2154
2155
2156
2157
2158static void switched_from_rt(struct rq *rq, struct task_struct *p)
2159{
2160
2161
2162
2163
2164
2165
2166
2167 if (!task_on_rq_queued(p) || rq->rt.rt_nr_running)
2168 return;
2169
2170 queue_pull_task(rq);
2171}
2172
2173void __init init_sched_rt_class(void)
2174{
2175 unsigned int i;
2176
2177 for_each_possible_cpu(i) {
2178 zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
2179 GFP_KERNEL, cpu_to_node(i));
2180 }
2181}
2182#endif
2183
2184
2185
2186
2187
2188
2189static void switched_to_rt(struct rq *rq, struct task_struct *p)
2190{
2191
2192
2193
2194
2195
2196
2197
2198 if (task_on_rq_queued(p) && rq->curr != p) {
2199#ifdef CONFIG_SMP
2200 if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
2201 queue_push_tasks(rq);
2202#else
2203 if (p->prio < rq->curr->prio)
2204 resched_curr(rq);
2205#endif
2206 }
2207}
2208
2209
2210
2211
2212
2213static void
2214prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
2215{
2216 if (!task_on_rq_queued(p))
2217 return;
2218
2219 if (rq->curr == p) {
2220#ifdef CONFIG_SMP
2221
2222
2223
2224
2225 if (oldprio < p->prio)
2226 queue_pull_task(rq);
2227
2228
2229
2230
2231
2232 if (p->prio > rq->rt.highest_prio.curr)
2233 resched_curr(rq);
2234#else
2235
2236 if (oldprio < p->prio)
2237 resched_curr(rq);
2238#endif
2239 } else {
2240
2241
2242
2243
2244
2245 if (p->prio < rq->curr->prio)
2246 resched_curr(rq);
2247 }
2248}
2249
2250static void watchdog(struct rq *rq, struct task_struct *p)
2251{
2252 unsigned long soft, hard;
2253
2254
2255 soft = task_rlimit(p, RLIMIT_RTTIME);
2256 hard = task_rlimit_max(p, RLIMIT_RTTIME);
2257
2258 if (soft != RLIM_INFINITY) {
2259 unsigned long next;
2260
2261 if (p->rt.watchdog_stamp != jiffies) {
2262 p->rt.timeout++;
2263 p->rt.watchdog_stamp = jiffies;
2264 }
2265
2266 next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
2267 if (p->rt.timeout > next)
2268 p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
2269 }
2270}
2271
2272static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
2273{
2274 struct sched_rt_entity *rt_se = &p->rt;
2275
2276 update_curr_rt(rq);
2277
2278 watchdog(rq, p);
2279
2280
2281
2282
2283
2284 if (p->policy != SCHED_RR)
2285 return;
2286
2287 if (--p->rt.time_slice)
2288 return;
2289
2290 p->rt.time_slice = sched_rr_timeslice;
2291
2292
2293
2294
2295
2296 for_each_sched_rt_entity(rt_se) {
2297 if (rt_se->run_list.prev != rt_se->run_list.next) {
2298 requeue_task_rt(rq, p, 0);
2299 resched_curr(rq);
2300 return;
2301 }
2302 }
2303}
2304
2305static void set_curr_task_rt(struct rq *rq)
2306{
2307 struct task_struct *p = rq->curr;
2308
2309 p->se.exec_start = rq_clock_task(rq);
2310
2311
2312 dequeue_pushable_task(rq, p);
2313}
2314
2315static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
2316{
2317
2318
2319
2320 if (task->policy == SCHED_RR)
2321 return sched_rr_timeslice;
2322 else
2323 return 0;
2324}
2325
2326const struct sched_class rt_sched_class = {
2327 .next = &fair_sched_class,
2328 .enqueue_task = enqueue_task_rt,
2329 .dequeue_task = dequeue_task_rt,
2330 .yield_task = yield_task_rt,
2331
2332 .check_preempt_curr = check_preempt_curr_rt,
2333
2334 .pick_next_task = pick_next_task_rt,
2335 .put_prev_task = put_prev_task_rt,
2336
2337#ifdef CONFIG_SMP
2338 .select_task_rq = select_task_rq_rt,
2339
2340 .set_cpus_allowed = set_cpus_allowed_common,
2341 .rq_online = rq_online_rt,
2342 .rq_offline = rq_offline_rt,
2343 .task_woken = task_woken_rt,
2344 .switched_from = switched_from_rt,
2345#endif
2346
2347 .set_curr_task = set_curr_task_rt,
2348 .task_tick = task_tick_rt,
2349
2350 .get_rr_interval = get_rr_interval_rt,
2351
2352 .prio_changed = prio_changed_rt,
2353 .switched_to = switched_to_rt,
2354
2355 .update_curr = update_curr_rt,
2356};
2357
2358#ifdef CONFIG_SCHED_DEBUG
2359extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
2360
2361void print_rt_stats(struct seq_file *m, int cpu)
2362{
2363 rt_rq_iter_t iter;
2364 struct rt_rq *rt_rq;
2365
2366 rcu_read_lock();
2367 for_each_rt_rq(rt_rq, iter, cpu_rq(cpu))
2368 print_rt_rq(m, cpu, rt_rq);
2369 rcu_read_unlock();
2370}
2371#endif
2372