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Commit | Line | Data |
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1 | /* | |
2 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR | |
3 | * policies) | |
4 | */ | |
5 | ||
6 | #include "sched.h" | |
7 | ||
8 | #include <linux/slab.h> | |
9 | #include <linux/irq_work.h> | |
10 | ||
11 | int sched_rr_timeslice = RR_TIMESLICE; | |
12 | ||
13 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
14 | ||
15 | struct rt_bandwidth def_rt_bandwidth; | |
16 | ||
17 | static 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 | ||
41 | void 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 | ||
53 | static 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 | * SCHED_DEADLINE updates the bandwidth, as a run away | |
63 | * RT task with a DL task could hog a CPU. But DL does | |
64 | * not reset the period. If a deadline task was running | |
65 | * without an RT task running, it can cause RT tasks to | |
66 | * throttle when they start up. Kick the timer right away | |
67 | * to update the period. | |
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) | |
76 | static void push_irq_work_func(struct irq_work *work); | |
77 | #endif | |
78 | ||
79 | void 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 | /* delimiter for bitsearch: */ | |
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 /* CONFIG_SMP */ | |
106 | /* We start is dequeued state, because no RT tasks are queued */ | |
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 | |
116 | static 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 | ||
123 | static 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 | ||
131 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) | |
132 | { | |
133 | return rt_rq->rq; | |
134 | } | |
135 | ||
136 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
137 | { | |
138 | return rt_se->rt_rq; | |
139 | } | |
140 | ||
141 | static 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 | ||
148 | void 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 | ||
166 | void 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 | ||
193 | int 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 | ||
227 | err_free_rq: | |
228 | kfree(rt_rq); | |
229 | err: | |
230 | return 0; | |
231 | } | |
232 | ||
233 | #else /* CONFIG_RT_GROUP_SCHED */ | |
234 | ||
235 | #define rt_entity_is_task(rt_se) (1) | |
236 | ||
237 | static 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 | ||
242 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) | |
243 | { | |
244 | return container_of(rt_rq, struct rq, rt); | |
245 | } | |
246 | ||
247 | static 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 | ||
254 | static 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 | ||
261 | void free_rt_sched_group(struct task_group *tg) { } | |
262 | ||
263 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
264 | { | |
265 | return 1; | |
266 | } | |
267 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
268 | ||
269 | #ifdef CONFIG_SMP | |
270 | ||
271 | static void pull_rt_task(struct rq *this_rq); | |
272 | ||
273 | static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) | |
274 | { | |
275 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
276 | return rq->rt.highest_prio.curr > prev->prio; | |
277 | } | |
278 | ||
279 | static inline int rt_overloaded(struct rq *rq) | |
280 | { | |
281 | return atomic_read(&rq->rd->rto_count); | |
282 | } | |
283 | ||
284 | static 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 | * Make sure the mask is visible before we set | |
292 | * the overload count. That is checked to determine | |
293 | * if we should look at the mask. It would be a shame | |
294 | * if we looked at the mask, but the mask was not | |
295 | * updated yet. | |
296 | * | |
297 | * Matched by the barrier in pull_rt_task(). | |
298 | */ | |
299 | smp_wmb(); | |
300 | atomic_inc(&rq->rd->rto_count); | |
301 | } | |
302 | ||
303 | static inline void rt_clear_overload(struct rq *rq) | |
304 | { | |
305 | if (!rq->online) | |
306 | return; | |
307 | ||
308 | /* the order here really doesn't matter */ | |
309 | atomic_dec(&rq->rd->rto_count); | |
310 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); | |
311 | } | |
312 | ||
313 | static 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 | ||
326 | static 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 (tsk_nr_cpus_allowed(p) > 1) | |
338 | rt_rq->rt_nr_migratory++; | |
339 | ||
340 | update_rt_migration(rt_rq); | |
341 | } | |
342 | ||
343 | static 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 (tsk_nr_cpus_allowed(p) > 1) | |
355 | rt_rq->rt_nr_migratory--; | |
356 | ||
357 | update_rt_migration(rt_rq); | |
358 | } | |
359 | ||
360 | static inline int has_pushable_tasks(struct rq *rq) | |
361 | { | |
362 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
363 | } | |
364 | ||
365 | static DEFINE_PER_CPU(struct callback_head, rt_push_head); | |
366 | static DEFINE_PER_CPU(struct callback_head, rt_pull_head); | |
367 | ||
368 | static void push_rt_tasks(struct rq *); | |
369 | static void pull_rt_task(struct rq *); | |
370 | ||
371 | static 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 | ||
379 | static 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 | ||
384 | static 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 | /* Update the highest prio pushable task */ | |
391 | if (p->prio < rq->rt.highest_prio.next) | |
392 | rq->rt.highest_prio.next = p->prio; | |
393 | } | |
394 | ||
395 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
396 | { | |
397 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
398 | ||
399 | /* Update the new highest prio pushable task */ | |
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 | ||
410 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) | |
411 | { | |
412 | } | |
413 | ||
414 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
415 | { | |
416 | } | |
417 | ||
418 | static inline | |
419 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
420 | { | |
421 | } | |
422 | ||
423 | static inline | |
424 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
425 | { | |
426 | } | |
427 | ||
428 | static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) | |
429 | { | |
430 | return false; | |
431 | } | |
432 | ||
433 | static inline void pull_rt_task(struct rq *this_rq) | |
434 | { | |
435 | } | |
436 | ||
437 | static inline void queue_push_tasks(struct rq *rq) | |
438 | { | |
439 | } | |
440 | #endif /* CONFIG_SMP */ | |
441 | ||
442 | static void enqueue_top_rt_rq(struct rt_rq *rt_rq); | |
443 | static void dequeue_top_rt_rq(struct rt_rq *rt_rq); | |
444 | ||
445 | static 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 | ||
452 | static 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 | ||
460 | static 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 | ||
465 | typedef struct task_group *rt_rq_iter_t; | |
466 | ||
467 | static 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 | ||
488 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
489 | { | |
490 | return rt_se->my_q; | |
491 | } | |
492 | ||
493 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); | |
494 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); | |
495 | ||
496 | static 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 | ||
517 | static 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 | ||
530 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) | |
531 | { | |
532 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
533 | } | |
534 | ||
535 | static 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 | |
548 | static inline const struct cpumask *sched_rt_period_mask(void) | |
549 | { | |
550 | return this_rq()->rd->span; | |
551 | } | |
552 | #else | |
553 | static inline const struct cpumask *sched_rt_period_mask(void) | |
554 | { | |
555 | return cpu_online_mask; | |
556 | } | |
557 | #endif | |
558 | ||
559 | static inline | |
560 | struct 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 | ||
565 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) | |
566 | { | |
567 | return &rt_rq->tg->rt_bandwidth; | |
568 | } | |
569 | ||
570 | #else /* !CONFIG_RT_GROUP_SCHED */ | |
571 | ||
572 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
573 | { | |
574 | return rt_rq->rt_runtime; | |
575 | } | |
576 | ||
577 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
578 | { | |
579 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
580 | } | |
581 | ||
582 | typedef 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 | ||
590 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
591 | { | |
592 | return NULL; | |
593 | } | |
594 | ||
595 | static 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 | ||
606 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) | |
607 | { | |
608 | dequeue_top_rt_rq(rt_rq); | |
609 | } | |
610 | ||
611 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) | |
612 | { | |
613 | return rt_rq->rt_throttled; | |
614 | } | |
615 | ||
616 | static inline const struct cpumask *sched_rt_period_mask(void) | |
617 | { | |
618 | return cpu_online_mask; | |
619 | } | |
620 | ||
621 | static inline | |
622 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
623 | { | |
624 | return &cpu_rq(cpu)->rt; | |
625 | } | |
626 | ||
627 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) | |
628 | { | |
629 | return &def_rt_bandwidth; | |
630 | } | |
631 | ||
632 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
633 | ||
634 | bool 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 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
645 | */ | |
646 | static 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 | * Either all rqs have inf runtime and there's nothing to steal | |
667 | * or __disable_runtime() below sets a specific rq to inf to | |
668 | * indicate its been disabled and disalow stealing. | |
669 | */ | |
670 | if (iter->rt_runtime == RUNTIME_INF) | |
671 | goto next; | |
672 | ||
673 | /* | |
674 | * From runqueues with spare time, take 1/n part of their | |
675 | * spare time, but no more than our period. | |
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 | } | |
689 | next: | |
690 | raw_spin_unlock(&iter->rt_runtime_lock); | |
691 | } | |
692 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
693 | } | |
694 | ||
695 | /* | |
696 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
697 | */ | |
698 | static 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 | * Either we're all inf and nobody needs to borrow, or we're | |
716 | * already disabled and thus have nothing to do, or we have | |
717 | * exactly the right amount of runtime to take out. | |
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 | * Calculate the difference between what we started out with | |
726 | * and what we current have, that's the amount of runtime | |
727 | * we lend and now have to reclaim. | |
728 | */ | |
729 | want = rt_b->rt_runtime - rt_rq->rt_runtime; | |
730 | ||
731 | /* | |
732 | * Greedy reclaim, take back as much as we can. | |
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 | * Can't reclaim from ourselves or disabled runqueues. | |
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 | * We cannot be left wanting - that would mean some runtime | |
762 | * leaked out of the system. | |
763 | */ | |
764 | BUG_ON(want); | |
765 | balanced: | |
766 | /* | |
767 | * Disable all the borrow logic by pretending we have inf | |
768 | * runtime - in which case borrowing doesn't make sense. | |
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 | /* Make rt_rq available for pick_next_task() */ | |
776 | sched_rt_rq_enqueue(rt_rq); | |
777 | } | |
778 | } | |
779 | ||
780 | static 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 | * Reset each runqueue's bandwidth settings | |
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 | ||
804 | static 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 /* !CONFIG_SMP */ | |
816 | static inline void balance_runtime(struct rt_rq *rt_rq) {} | |
817 | #endif /* CONFIG_SMP */ | |
818 | ||
819 | static 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 | * FIXME: isolated CPUs should really leave the root task group, | |
828 | * whether they are isolcpus or were isolated via cpusets, lest | |
829 | * the timer run on a CPU which does not service all runqueues, | |
830 | * potentially leaving other CPUs indefinitely throttled. If | |
831 | * isolation is really required, the user will turn the throttle | |
832 | * off to kill the perturbations it causes anyway. Meanwhile, | |
833 | * this maintains functionality for boot and/or troubleshooting. | |
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 | * When we're idle and a woken (rt) task is | |
858 | * throttled check_preempt_curr() will set | |
859 | * skip_update and the time between the wakeup | |
860 | * and this unthrottle will get accounted as | |
861 | * 'runtime'. | |
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 | ||
888 | static 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 | ||
900 | static 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 | * Don't actually throttle groups that have no runtime assigned | |
920 | * but accrue some time due to boosting. | |
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 | * In case we did anyway, make it go away, | |
928 | * replenishment is a joke, since it will replenish us | |
929 | * with exactly 0 ns. | |
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 | * Update the current task's runtime statistics. Skip current tasks that | |
945 | * are not in our scheduling class. | |
946 | */ | |
947 | static 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 | delta_exec = rq_clock_task(rq) - curr->se.exec_start; | |
957 | if (unlikely((s64)delta_exec <= 0)) | |
958 | return; | |
959 | ||
960 | /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ | |
961 | cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT); | |
962 | ||
963 | schedstat_set(curr->se.statistics.exec_max, | |
964 | max(curr->se.statistics.exec_max, delta_exec)); | |
965 | ||
966 | curr->se.sum_exec_runtime += delta_exec; | |
967 | account_group_exec_runtime(curr, delta_exec); | |
968 | ||
969 | curr->se.exec_start = rq_clock_task(rq); | |
970 | cpuacct_charge(curr, delta_exec); | |
971 | ||
972 | sched_rt_avg_update(rq, delta_exec); | |
973 | ||
974 | if (!rt_bandwidth_enabled()) | |
975 | return; | |
976 | ||
977 | for_each_sched_rt_entity(rt_se) { | |
978 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
979 | ||
980 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { | |
981 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
982 | rt_rq->rt_time += delta_exec; | |
983 | if (sched_rt_runtime_exceeded(rt_rq)) | |
984 | resched_curr(rq); | |
985 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
986 | } | |
987 | } | |
988 | } | |
989 | ||
990 | static void | |
991 | dequeue_top_rt_rq(struct rt_rq *rt_rq) | |
992 | { | |
993 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
994 | ||
995 | BUG_ON(&rq->rt != rt_rq); | |
996 | ||
997 | if (!rt_rq->rt_queued) | |
998 | return; | |
999 | ||
1000 | BUG_ON(!rq->nr_running); | |
1001 | ||
1002 | sub_nr_running(rq, rt_rq->rt_nr_running); | |
1003 | rt_rq->rt_queued = 0; | |
1004 | } | |
1005 | ||
1006 | static void | |
1007 | enqueue_top_rt_rq(struct rt_rq *rt_rq) | |
1008 | { | |
1009 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1010 | ||
1011 | BUG_ON(&rq->rt != rt_rq); | |
1012 | ||
1013 | if (rt_rq->rt_queued) | |
1014 | return; | |
1015 | if (rt_rq_throttled(rt_rq) || !rt_rq->rt_nr_running) | |
1016 | return; | |
1017 | ||
1018 | add_nr_running(rq, rt_rq->rt_nr_running); | |
1019 | rt_rq->rt_queued = 1; | |
1020 | } | |
1021 | ||
1022 | #if defined CONFIG_SMP | |
1023 | ||
1024 | static void | |
1025 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
1026 | { | |
1027 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1028 | ||
1029 | #ifdef CONFIG_RT_GROUP_SCHED | |
1030 | /* | |
1031 | * Change rq's cpupri only if rt_rq is the top queue. | |
1032 | */ | |
1033 | if (&rq->rt != rt_rq) | |
1034 | return; | |
1035 | #endif | |
1036 | if (rq->online && prio < prev_prio) | |
1037 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); | |
1038 | } | |
1039 | ||
1040 | static void | |
1041 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
1042 | { | |
1043 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1044 | ||
1045 | #ifdef CONFIG_RT_GROUP_SCHED | |
1046 | /* | |
1047 | * Change rq's cpupri only if rt_rq is the top queue. | |
1048 | */ | |
1049 | if (&rq->rt != rt_rq) | |
1050 | return; | |
1051 | #endif | |
1052 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) | |
1053 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
1054 | } | |
1055 | ||
1056 | #else /* CONFIG_SMP */ | |
1057 | ||
1058 | static inline | |
1059 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
1060 | static inline | |
1061 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
1062 | ||
1063 | #endif /* CONFIG_SMP */ | |
1064 | ||
1065 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED | |
1066 | static void | |
1067 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
1068 | { | |
1069 | int prev_prio = rt_rq->highest_prio.curr; | |
1070 | ||
1071 | if (prio < prev_prio) | |
1072 | rt_rq->highest_prio.curr = prio; | |
1073 | ||
1074 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
1075 | } | |
1076 | ||
1077 | static void | |
1078 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
1079 | { | |
1080 | int prev_prio = rt_rq->highest_prio.curr; | |
1081 | ||
1082 | if (rt_rq->rt_nr_running) { | |
1083 | ||
1084 | WARN_ON(prio < prev_prio); | |
1085 | ||
1086 | /* | |
1087 | * This may have been our highest task, and therefore | |
1088 | * we may have some recomputation to do | |
1089 | */ | |
1090 | if (prio == prev_prio) { | |
1091 | struct rt_prio_array *array = &rt_rq->active; | |
1092 | ||
1093 | rt_rq->highest_prio.curr = | |
1094 | sched_find_first_bit(array->bitmap); | |
1095 | } | |
1096 | ||
1097 | } else | |
1098 | rt_rq->highest_prio.curr = MAX_RT_PRIO; | |
1099 | ||
1100 | dec_rt_prio_smp(rt_rq, prio, prev_prio); | |
1101 | } | |
1102 | ||
1103 | #else | |
1104 | ||
1105 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1106 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1107 | ||
1108 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
1109 | ||
1110 | #ifdef CONFIG_RT_GROUP_SCHED | |
1111 | ||
1112 | static void | |
1113 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1114 | { | |
1115 | if (rt_se_boosted(rt_se)) | |
1116 | rt_rq->rt_nr_boosted++; | |
1117 | ||
1118 | if (rt_rq->tg) | |
1119 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
1120 | } | |
1121 | ||
1122 | static void | |
1123 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1124 | { | |
1125 | if (rt_se_boosted(rt_se)) | |
1126 | rt_rq->rt_nr_boosted--; | |
1127 | ||
1128 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
1129 | } | |
1130 | ||
1131 | #else /* CONFIG_RT_GROUP_SCHED */ | |
1132 | ||
1133 | static void | |
1134 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1135 | { | |
1136 | start_rt_bandwidth(&def_rt_bandwidth); | |
1137 | } | |
1138 | ||
1139 | static inline | |
1140 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
1141 | ||
1142 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
1143 | ||
1144 | static inline | |
1145 | unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se) | |
1146 | { | |
1147 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1148 | ||
1149 | if (group_rq) | |
1150 | return group_rq->rt_nr_running; | |
1151 | else | |
1152 | return 1; | |
1153 | } | |
1154 | ||
1155 | static inline | |
1156 | unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se) | |
1157 | { | |
1158 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1159 | struct task_struct *tsk; | |
1160 | ||
1161 | if (group_rq) | |
1162 | return group_rq->rr_nr_running; | |
1163 | ||
1164 | tsk = rt_task_of(rt_se); | |
1165 | ||
1166 | return (tsk->policy == SCHED_RR) ? 1 : 0; | |
1167 | } | |
1168 | ||
1169 | static inline | |
1170 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1171 | { | |
1172 | int prio = rt_se_prio(rt_se); | |
1173 | ||
1174 | WARN_ON(!rt_prio(prio)); | |
1175 | rt_rq->rt_nr_running += rt_se_nr_running(rt_se); | |
1176 | rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se); | |
1177 | ||
1178 | inc_rt_prio(rt_rq, prio); | |
1179 | inc_rt_migration(rt_se, rt_rq); | |
1180 | inc_rt_group(rt_se, rt_rq); | |
1181 | } | |
1182 | ||
1183 | static inline | |
1184 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1185 | { | |
1186 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
1187 | WARN_ON(!rt_rq->rt_nr_running); | |
1188 | rt_rq->rt_nr_running -= rt_se_nr_running(rt_se); | |
1189 | rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se); | |
1190 | ||
1191 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
1192 | dec_rt_migration(rt_se, rt_rq); | |
1193 | dec_rt_group(rt_se, rt_rq); | |
1194 | } | |
1195 | ||
1196 | /* | |
1197 | * Change rt_se->run_list location unless SAVE && !MOVE | |
1198 | * | |
1199 | * assumes ENQUEUE/DEQUEUE flags match | |
1200 | */ | |
1201 | static inline bool move_entity(unsigned int flags) | |
1202 | { | |
1203 | if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE) | |
1204 | return false; | |
1205 | ||
1206 | return true; | |
1207 | } | |
1208 | ||
1209 | static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array) | |
1210 | { | |
1211 | list_del_init(&rt_se->run_list); | |
1212 | ||
1213 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
1214 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
1215 | ||
1216 | rt_se->on_list = 0; | |
1217 | } | |
1218 | ||
1219 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) | |
1220 | { | |
1221 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
1222 | struct rt_prio_array *array = &rt_rq->active; | |
1223 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1224 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
1225 | ||
1226 | /* | |
1227 | * Don't enqueue the group if its throttled, or when empty. | |
1228 | * The latter is a consequence of the former when a child group | |
1229 | * get throttled and the current group doesn't have any other | |
1230 | * active members. | |
1231 | */ | |
1232 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) { | |
1233 | if (rt_se->on_list) | |
1234 | __delist_rt_entity(rt_se, array); | |
1235 | return; | |
1236 | } | |
1237 | ||
1238 | if (move_entity(flags)) { | |
1239 | WARN_ON_ONCE(rt_se->on_list); | |
1240 | if (flags & ENQUEUE_HEAD) | |
1241 | list_add(&rt_se->run_list, queue); | |
1242 | else | |
1243 | list_add_tail(&rt_se->run_list, queue); | |
1244 | ||
1245 | __set_bit(rt_se_prio(rt_se), array->bitmap); | |
1246 | rt_se->on_list = 1; | |
1247 | } | |
1248 | rt_se->on_rq = 1; | |
1249 | ||
1250 | inc_rt_tasks(rt_se, rt_rq); | |
1251 | } | |
1252 | ||
1253 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) | |
1254 | { | |
1255 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
1256 | struct rt_prio_array *array = &rt_rq->active; | |
1257 | ||
1258 | if (move_entity(flags)) { | |
1259 | WARN_ON_ONCE(!rt_se->on_list); | |
1260 | __delist_rt_entity(rt_se, array); | |
1261 | } | |
1262 | rt_se->on_rq = 0; | |
1263 | ||
1264 | dec_rt_tasks(rt_se, rt_rq); | |
1265 | } | |
1266 | ||
1267 | /* | |
1268 | * Because the prio of an upper entry depends on the lower | |
1269 | * entries, we must remove entries top - down. | |
1270 | */ | |
1271 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags) | |
1272 | { | |
1273 | struct sched_rt_entity *back = NULL; | |
1274 | ||
1275 | for_each_sched_rt_entity(rt_se) { | |
1276 | rt_se->back = back; | |
1277 | back = rt_se; | |
1278 | } | |
1279 | ||
1280 | dequeue_top_rt_rq(rt_rq_of_se(back)); | |
1281 | ||
1282 | for (rt_se = back; rt_se; rt_se = rt_se->back) { | |
1283 | if (on_rt_rq(rt_se)) | |
1284 | __dequeue_rt_entity(rt_se, flags); | |
1285 | } | |
1286 | } | |
1287 | ||
1288 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) | |
1289 | { | |
1290 | struct rq *rq = rq_of_rt_se(rt_se); | |
1291 | ||
1292 | dequeue_rt_stack(rt_se, flags); | |
1293 | for_each_sched_rt_entity(rt_se) | |
1294 | __enqueue_rt_entity(rt_se, flags); | |
1295 | enqueue_top_rt_rq(&rq->rt); | |
1296 | } | |
1297 | ||
1298 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) | |
1299 | { | |
1300 | struct rq *rq = rq_of_rt_se(rt_se); | |
1301 | ||
1302 | dequeue_rt_stack(rt_se, flags); | |
1303 | ||
1304 | for_each_sched_rt_entity(rt_se) { | |
1305 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
1306 | ||
1307 | if (rt_rq && rt_rq->rt_nr_running) | |
1308 | __enqueue_rt_entity(rt_se, flags); | |
1309 | } | |
1310 | enqueue_top_rt_rq(&rq->rt); | |
1311 | } | |
1312 | ||
1313 | /* | |
1314 | * Adding/removing a task to/from a priority array: | |
1315 | */ | |
1316 | static void | |
1317 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) | |
1318 | { | |
1319 | struct sched_rt_entity *rt_se = &p->rt; | |
1320 | ||
1321 | if (flags & ENQUEUE_WAKEUP) | |
1322 | rt_se->timeout = 0; | |
1323 | ||
1324 | enqueue_rt_entity(rt_se, flags); | |
1325 | ||
1326 | if (!task_current(rq, p) && tsk_nr_cpus_allowed(p) > 1) | |
1327 | enqueue_pushable_task(rq, p); | |
1328 | } | |
1329 | ||
1330 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) | |
1331 | { | |
1332 | struct sched_rt_entity *rt_se = &p->rt; | |
1333 | ||
1334 | update_curr_rt(rq); | |
1335 | dequeue_rt_entity(rt_se, flags); | |
1336 | ||
1337 | dequeue_pushable_task(rq, p); | |
1338 | } | |
1339 | ||
1340 | /* | |
1341 | * Put task to the head or the end of the run list without the overhead of | |
1342 | * dequeue followed by enqueue. | |
1343 | */ | |
1344 | static void | |
1345 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
1346 | { | |
1347 | if (on_rt_rq(rt_se)) { | |
1348 | struct rt_prio_array *array = &rt_rq->active; | |
1349 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
1350 | ||
1351 | if (head) | |
1352 | list_move(&rt_se->run_list, queue); | |
1353 | else | |
1354 | list_move_tail(&rt_se->run_list, queue); | |
1355 | } | |
1356 | } | |
1357 | ||
1358 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) | |
1359 | { | |
1360 | struct sched_rt_entity *rt_se = &p->rt; | |
1361 | struct rt_rq *rt_rq; | |
1362 | ||
1363 | for_each_sched_rt_entity(rt_se) { | |
1364 | rt_rq = rt_rq_of_se(rt_se); | |
1365 | requeue_rt_entity(rt_rq, rt_se, head); | |
1366 | } | |
1367 | } | |
1368 | ||
1369 | static void yield_task_rt(struct rq *rq) | |
1370 | { | |
1371 | requeue_task_rt(rq, rq->curr, 0); | |
1372 | } | |
1373 | ||
1374 | #ifdef CONFIG_SMP | |
1375 | static int find_lowest_rq(struct task_struct *task); | |
1376 | ||
1377 | static int | |
1378 | select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags) | |
1379 | { | |
1380 | struct task_struct *curr; | |
1381 | struct rq *rq; | |
1382 | ||
1383 | /* For anything but wake ups, just return the task_cpu */ | |
1384 | if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK) | |
1385 | goto out; | |
1386 | ||
1387 | rq = cpu_rq(cpu); | |
1388 | ||
1389 | rcu_read_lock(); | |
1390 | curr = READ_ONCE(rq->curr); /* unlocked access */ | |
1391 | ||
1392 | /* | |
1393 | * If the current task on @p's runqueue is an RT task, then | |
1394 | * try to see if we can wake this RT task up on another | |
1395 | * runqueue. Otherwise simply start this RT task | |
1396 | * on its current runqueue. | |
1397 | * | |
1398 | * We want to avoid overloading runqueues. If the woken | |
1399 | * task is a higher priority, then it will stay on this CPU | |
1400 | * and the lower prio task should be moved to another CPU. | |
1401 | * Even though this will probably make the lower prio task | |
1402 | * lose its cache, we do not want to bounce a higher task | |
1403 | * around just because it gave up its CPU, perhaps for a | |
1404 | * lock? | |
1405 | * | |
1406 | * For equal prio tasks, we just let the scheduler sort it out. | |
1407 | * | |
1408 | * Otherwise, just let it ride on the affined RQ and the | |
1409 | * post-schedule router will push the preempted task away | |
1410 | * | |
1411 | * This test is optimistic, if we get it wrong the load-balancer | |
1412 | * will have to sort it out. | |
1413 | */ | |
1414 | if (curr && unlikely(rt_task(curr)) && | |
1415 | (tsk_nr_cpus_allowed(curr) < 2 || | |
1416 | curr->prio <= p->prio)) { | |
1417 | int target = find_lowest_rq(p); | |
1418 | ||
1419 | /* | |
1420 | * Don't bother moving it if the destination CPU is | |
1421 | * not running a lower priority task. | |
1422 | */ | |
1423 | if (target != -1 && | |
1424 | p->prio < cpu_rq(target)->rt.highest_prio.curr) | |
1425 | cpu = target; | |
1426 | } | |
1427 | rcu_read_unlock(); | |
1428 | ||
1429 | out: | |
1430 | return cpu; | |
1431 | } | |
1432 | ||
1433 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1434 | { | |
1435 | /* | |
1436 | * Current can't be migrated, useless to reschedule, | |
1437 | * let's hope p can move out. | |
1438 | */ | |
1439 | if (tsk_nr_cpus_allowed(rq->curr) == 1 || | |
1440 | !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) | |
1441 | return; | |
1442 | ||
1443 | /* | |
1444 | * p is migratable, so let's not schedule it and | |
1445 | * see if it is pushed or pulled somewhere else. | |
1446 | */ | |
1447 | if (tsk_nr_cpus_allowed(p) != 1 | |
1448 | && cpupri_find(&rq->rd->cpupri, p, NULL)) | |
1449 | return; | |
1450 | ||
1451 | /* | |
1452 | * There appears to be other cpus that can accept | |
1453 | * current and none to run 'p', so lets reschedule | |
1454 | * to try and push current away: | |
1455 | */ | |
1456 | requeue_task_rt(rq, p, 1); | |
1457 | resched_curr(rq); | |
1458 | } | |
1459 | ||
1460 | #endif /* CONFIG_SMP */ | |
1461 | ||
1462 | /* | |
1463 | * Preempt the current task with a newly woken task if needed: | |
1464 | */ | |
1465 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) | |
1466 | { | |
1467 | if (p->prio < rq->curr->prio) { | |
1468 | resched_curr(rq); | |
1469 | return; | |
1470 | } | |
1471 | ||
1472 | #ifdef CONFIG_SMP | |
1473 | /* | |
1474 | * If: | |
1475 | * | |
1476 | * - the newly woken task is of equal priority to the current task | |
1477 | * - the newly woken task is non-migratable while current is migratable | |
1478 | * - current will be preempted on the next reschedule | |
1479 | * | |
1480 | * we should check to see if current can readily move to a different | |
1481 | * cpu. If so, we will reschedule to allow the push logic to try | |
1482 | * to move current somewhere else, making room for our non-migratable | |
1483 | * task. | |
1484 | */ | |
1485 | if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) | |
1486 | check_preempt_equal_prio(rq, p); | |
1487 | #endif | |
1488 | } | |
1489 | ||
1490 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, | |
1491 | struct rt_rq *rt_rq) | |
1492 | { | |
1493 | struct rt_prio_array *array = &rt_rq->active; | |
1494 | struct sched_rt_entity *next = NULL; | |
1495 | struct list_head *queue; | |
1496 | int idx; | |
1497 | ||
1498 | idx = sched_find_first_bit(array->bitmap); | |
1499 | BUG_ON(idx >= MAX_RT_PRIO); | |
1500 | ||
1501 | queue = array->queue + idx; | |
1502 | next = list_entry(queue->next, struct sched_rt_entity, run_list); | |
1503 | ||
1504 | return next; | |
1505 | } | |
1506 | ||
1507 | static struct task_struct *_pick_next_task_rt(struct rq *rq) | |
1508 | { | |
1509 | struct sched_rt_entity *rt_se; | |
1510 | struct task_struct *p; | |
1511 | struct rt_rq *rt_rq = &rq->rt; | |
1512 | ||
1513 | do { | |
1514 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
1515 | BUG_ON(!rt_se); | |
1516 | rt_rq = group_rt_rq(rt_se); | |
1517 | } while (rt_rq); | |
1518 | ||
1519 | p = rt_task_of(rt_se); | |
1520 | p->se.exec_start = rq_clock_task(rq); | |
1521 | ||
1522 | return p; | |
1523 | } | |
1524 | ||
1525 | static struct task_struct * | |
1526 | pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct pin_cookie cookie) | |
1527 | { | |
1528 | struct task_struct *p; | |
1529 | struct rt_rq *rt_rq = &rq->rt; | |
1530 | ||
1531 | if (need_pull_rt_task(rq, prev)) { | |
1532 | /* | |
1533 | * This is OK, because current is on_cpu, which avoids it being | |
1534 | * picked for load-balance and preemption/IRQs are still | |
1535 | * disabled avoiding further scheduler activity on it and we're | |
1536 | * being very careful to re-start the picking loop. | |
1537 | */ | |
1538 | lockdep_unpin_lock(&rq->lock, cookie); | |
1539 | pull_rt_task(rq); | |
1540 | lockdep_repin_lock(&rq->lock, cookie); | |
1541 | /* | |
1542 | * pull_rt_task() can drop (and re-acquire) rq->lock; this | |
1543 | * means a dl or stop task can slip in, in which case we need | |
1544 | * to re-start task selection. | |
1545 | */ | |
1546 | if (unlikely((rq->stop && task_on_rq_queued(rq->stop)) || | |
1547 | rq->dl.dl_nr_running)) | |
1548 | return RETRY_TASK; | |
1549 | } | |
1550 | ||
1551 | /* | |
1552 | * We may dequeue prev's rt_rq in put_prev_task(). | |
1553 | * So, we update time before rt_nr_running check. | |
1554 | */ | |
1555 | if (prev->sched_class == &rt_sched_class) | |
1556 | update_curr_rt(rq); | |
1557 | ||
1558 | if (!rt_rq->rt_queued) | |
1559 | return NULL; | |
1560 | ||
1561 | put_prev_task(rq, prev); | |
1562 | ||
1563 | p = _pick_next_task_rt(rq); | |
1564 | ||
1565 | /* The running task is never eligible for pushing */ | |
1566 | dequeue_pushable_task(rq, p); | |
1567 | ||
1568 | queue_push_tasks(rq); | |
1569 | ||
1570 | return p; | |
1571 | } | |
1572 | ||
1573 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) | |
1574 | { | |
1575 | update_curr_rt(rq); | |
1576 | ||
1577 | /* | |
1578 | * The previous task needs to be made eligible for pushing | |
1579 | * if it is still active | |
1580 | */ | |
1581 | if (on_rt_rq(&p->rt) && tsk_nr_cpus_allowed(p) > 1) | |
1582 | enqueue_pushable_task(rq, p); | |
1583 | } | |
1584 | ||
1585 | #ifdef CONFIG_SMP | |
1586 | ||
1587 | /* Only try algorithms three times */ | |
1588 | #define RT_MAX_TRIES 3 | |
1589 | ||
1590 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) | |
1591 | { | |
1592 | if (!task_running(rq, p) && | |
1593 | cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) | |
1594 | return 1; | |
1595 | return 0; | |
1596 | } | |
1597 | ||
1598 | /* | |
1599 | * Return the highest pushable rq's task, which is suitable to be executed | |
1600 | * on the cpu, NULL otherwise | |
1601 | */ | |
1602 | static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu) | |
1603 | { | |
1604 | struct plist_head *head = &rq->rt.pushable_tasks; | |
1605 | struct task_struct *p; | |
1606 | ||
1607 | if (!has_pushable_tasks(rq)) | |
1608 | return NULL; | |
1609 | ||
1610 | plist_for_each_entry(p, head, pushable_tasks) { | |
1611 | if (pick_rt_task(rq, p, cpu)) | |
1612 | return p; | |
1613 | } | |
1614 | ||
1615 | return NULL; | |
1616 | } | |
1617 | ||
1618 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); | |
1619 | ||
1620 | static int find_lowest_rq(struct task_struct *task) | |
1621 | { | |
1622 | struct sched_domain *sd; | |
1623 | struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask); | |
1624 | int this_cpu = smp_processor_id(); | |
1625 | int cpu = task_cpu(task); | |
1626 | ||
1627 | /* Make sure the mask is initialized first */ | |
1628 | if (unlikely(!lowest_mask)) | |
1629 | return -1; | |
1630 | ||
1631 | if (tsk_nr_cpus_allowed(task) == 1) | |
1632 | return -1; /* No other targets possible */ | |
1633 | ||
1634 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) | |
1635 | return -1; /* No targets found */ | |
1636 | ||
1637 | /* | |
1638 | * At this point we have built a mask of cpus representing the | |
1639 | * lowest priority tasks in the system. Now we want to elect | |
1640 | * the best one based on our affinity and topology. | |
1641 | * | |
1642 | * We prioritize the last cpu that the task executed on since | |
1643 | * it is most likely cache-hot in that location. | |
1644 | */ | |
1645 | if (cpumask_test_cpu(cpu, lowest_mask)) | |
1646 | return cpu; | |
1647 | ||
1648 | /* | |
1649 | * Otherwise, we consult the sched_domains span maps to figure | |
1650 | * out which cpu is logically closest to our hot cache data. | |
1651 | */ | |
1652 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) | |
1653 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
1654 | ||
1655 | rcu_read_lock(); | |
1656 | for_each_domain(cpu, sd) { | |
1657 | if (sd->flags & SD_WAKE_AFFINE) { | |
1658 | int best_cpu; | |
1659 | ||
1660 | /* | |
1661 | * "this_cpu" is cheaper to preempt than a | |
1662 | * remote processor. | |
1663 | */ | |
1664 | if (this_cpu != -1 && | |
1665 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { | |
1666 | rcu_read_unlock(); | |
1667 | return this_cpu; | |
1668 | } | |
1669 | ||
1670 | best_cpu = cpumask_first_and(lowest_mask, | |
1671 | sched_domain_span(sd)); | |
1672 | if (best_cpu < nr_cpu_ids) { | |
1673 | rcu_read_unlock(); | |
1674 | return best_cpu; | |
1675 | } | |
1676 | } | |
1677 | } | |
1678 | rcu_read_unlock(); | |
1679 | ||
1680 | /* | |
1681 | * And finally, if there were no matches within the domains | |
1682 | * just give the caller *something* to work with from the compatible | |
1683 | * locations. | |
1684 | */ | |
1685 | if (this_cpu != -1) | |
1686 | return this_cpu; | |
1687 | ||
1688 | cpu = cpumask_any(lowest_mask); | |
1689 | if (cpu < nr_cpu_ids) | |
1690 | return cpu; | |
1691 | return -1; | |
1692 | } | |
1693 | ||
1694 | /* Will lock the rq it finds */ | |
1695 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) | |
1696 | { | |
1697 | struct rq *lowest_rq = NULL; | |
1698 | int tries; | |
1699 | int cpu; | |
1700 | ||
1701 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { | |
1702 | cpu = find_lowest_rq(task); | |
1703 | ||
1704 | if ((cpu == -1) || (cpu == rq->cpu)) | |
1705 | break; | |
1706 | ||
1707 | lowest_rq = cpu_rq(cpu); | |
1708 | ||
1709 | if (lowest_rq->rt.highest_prio.curr <= task->prio) { | |
1710 | /* | |
1711 | * Target rq has tasks of equal or higher priority, | |
1712 | * retrying does not release any lock and is unlikely | |
1713 | * to yield a different result. | |
1714 | */ | |
1715 | lowest_rq = NULL; | |
1716 | break; | |
1717 | } | |
1718 | ||
1719 | /* if the prio of this runqueue changed, try again */ | |
1720 | if (double_lock_balance(rq, lowest_rq)) { | |
1721 | /* | |
1722 | * We had to unlock the run queue. In | |
1723 | * the mean time, task could have | |
1724 | * migrated already or had its affinity changed. | |
1725 | * Also make sure that it wasn't scheduled on its rq. | |
1726 | */ | |
1727 | if (unlikely(task_rq(task) != rq || | |
1728 | !cpumask_test_cpu(lowest_rq->cpu, | |
1729 | tsk_cpus_allowed(task)) || | |
1730 | task_running(rq, task) || | |
1731 | !rt_task(task) || | |
1732 | !task_on_rq_queued(task))) { | |
1733 | ||
1734 | double_unlock_balance(rq, lowest_rq); | |
1735 | lowest_rq = NULL; | |
1736 | break; | |
1737 | } | |
1738 | } | |
1739 | ||
1740 | /* If this rq is still suitable use it. */ | |
1741 | if (lowest_rq->rt.highest_prio.curr > task->prio) | |
1742 | break; | |
1743 | ||
1744 | /* try again */ | |
1745 | double_unlock_balance(rq, lowest_rq); | |
1746 | lowest_rq = NULL; | |
1747 | } | |
1748 | ||
1749 | return lowest_rq; | |
1750 | } | |
1751 | ||
1752 | static struct task_struct *pick_next_pushable_task(struct rq *rq) | |
1753 | { | |
1754 | struct task_struct *p; | |
1755 | ||
1756 | if (!has_pushable_tasks(rq)) | |
1757 | return NULL; | |
1758 | ||
1759 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1760 | struct task_struct, pushable_tasks); | |
1761 | ||
1762 | BUG_ON(rq->cpu != task_cpu(p)); | |
1763 | BUG_ON(task_current(rq, p)); | |
1764 | BUG_ON(tsk_nr_cpus_allowed(p) <= 1); | |
1765 | ||
1766 | BUG_ON(!task_on_rq_queued(p)); | |
1767 | BUG_ON(!rt_task(p)); | |
1768 | ||
1769 | return p; | |
1770 | } | |
1771 | ||
1772 | /* | |
1773 | * If the current CPU has more than one RT task, see if the non | |
1774 | * running task can migrate over to a CPU that is running a task | |
1775 | * of lesser priority. | |
1776 | */ | |
1777 | static int push_rt_task(struct rq *rq) | |
1778 | { | |
1779 | struct task_struct *next_task; | |
1780 | struct rq *lowest_rq; | |
1781 | int ret = 0; | |
1782 | ||
1783 | if (!rq->rt.overloaded) | |
1784 | return 0; | |
1785 | ||
1786 | next_task = pick_next_pushable_task(rq); | |
1787 | if (!next_task) | |
1788 | return 0; | |
1789 | ||
1790 | retry: | |
1791 | if (unlikely(next_task == rq->curr)) { | |
1792 | WARN_ON(1); | |
1793 | return 0; | |
1794 | } | |
1795 | ||
1796 | /* | |
1797 | * It's possible that the next_task slipped in of | |
1798 | * higher priority than current. If that's the case | |
1799 | * just reschedule current. | |
1800 | */ | |
1801 | if (unlikely(next_task->prio < rq->curr->prio)) { | |
1802 | resched_curr(rq); | |
1803 | return 0; | |
1804 | } | |
1805 | ||
1806 | /* We might release rq lock */ | |
1807 | get_task_struct(next_task); | |
1808 | ||
1809 | /* find_lock_lowest_rq locks the rq if found */ | |
1810 | lowest_rq = find_lock_lowest_rq(next_task, rq); | |
1811 | if (!lowest_rq) { | |
1812 | struct task_struct *task; | |
1813 | /* | |
1814 | * find_lock_lowest_rq releases rq->lock | |
1815 | * so it is possible that next_task has migrated. | |
1816 | * | |
1817 | * We need to make sure that the task is still on the same | |
1818 | * run-queue and is also still the next task eligible for | |
1819 | * pushing. | |
1820 | */ | |
1821 | task = pick_next_pushable_task(rq); | |
1822 | if (task_cpu(next_task) == rq->cpu && task == next_task) { | |
1823 | /* | |
1824 | * The task hasn't migrated, and is still the next | |
1825 | * eligible task, but we failed to find a run-queue | |
1826 | * to push it to. Do not retry in this case, since | |
1827 | * other cpus will pull from us when ready. | |
1828 | */ | |
1829 | goto out; | |
1830 | } | |
1831 | ||
1832 | if (!task) | |
1833 | /* No more tasks, just exit */ | |
1834 | goto out; | |
1835 | ||
1836 | /* | |
1837 | * Something has shifted, try again. | |
1838 | */ | |
1839 | put_task_struct(next_task); | |
1840 | next_task = task; | |
1841 | goto retry; | |
1842 | } | |
1843 | ||
1844 | deactivate_task(rq, next_task, 0); | |
1845 | set_task_cpu(next_task, lowest_rq->cpu); | |
1846 | activate_task(lowest_rq, next_task, 0); | |
1847 | ret = 1; | |
1848 | ||
1849 | resched_curr(lowest_rq); | |
1850 | ||
1851 | double_unlock_balance(rq, lowest_rq); | |
1852 | ||
1853 | out: | |
1854 | put_task_struct(next_task); | |
1855 | ||
1856 | return ret; | |
1857 | } | |
1858 | ||
1859 | static void push_rt_tasks(struct rq *rq) | |
1860 | { | |
1861 | /* push_rt_task will return true if it moved an RT */ | |
1862 | while (push_rt_task(rq)) | |
1863 | ; | |
1864 | } | |
1865 | ||
1866 | #ifdef HAVE_RT_PUSH_IPI | |
1867 | /* | |
1868 | * The search for the next cpu always starts at rq->cpu and ends | |
1869 | * when we reach rq->cpu again. It will never return rq->cpu. | |
1870 | * This returns the next cpu to check, or nr_cpu_ids if the loop | |
1871 | * is complete. | |
1872 | * | |
1873 | * rq->rt.push_cpu holds the last cpu returned by this function, | |
1874 | * or if this is the first instance, it must hold rq->cpu. | |
1875 | */ | |
1876 | static int rto_next_cpu(struct rq *rq) | |
1877 | { | |
1878 | int prev_cpu = rq->rt.push_cpu; | |
1879 | int cpu; | |
1880 | ||
1881 | cpu = cpumask_next(prev_cpu, rq->rd->rto_mask); | |
1882 | ||
1883 | /* | |
1884 | * If the previous cpu is less than the rq's CPU, then it already | |
1885 | * passed the end of the mask, and has started from the beginning. | |
1886 | * We end if the next CPU is greater or equal to rq's CPU. | |
1887 | */ | |
1888 | if (prev_cpu < rq->cpu) { | |
1889 | if (cpu >= rq->cpu) | |
1890 | return nr_cpu_ids; | |
1891 | ||
1892 | } else if (cpu >= nr_cpu_ids) { | |
1893 | /* | |
1894 | * We passed the end of the mask, start at the beginning. | |
1895 | * If the result is greater or equal to the rq's CPU, then | |
1896 | * the loop is finished. | |
1897 | */ | |
1898 | cpu = cpumask_first(rq->rd->rto_mask); | |
1899 | if (cpu >= rq->cpu) | |
1900 | return nr_cpu_ids; | |
1901 | } | |
1902 | rq->rt.push_cpu = cpu; | |
1903 | ||
1904 | /* Return cpu to let the caller know if the loop is finished or not */ | |
1905 | return cpu; | |
1906 | } | |
1907 | ||
1908 | static int find_next_push_cpu(struct rq *rq) | |
1909 | { | |
1910 | struct rq *next_rq; | |
1911 | int cpu; | |
1912 | ||
1913 | while (1) { | |
1914 | cpu = rto_next_cpu(rq); | |
1915 | if (cpu >= nr_cpu_ids) | |
1916 | break; | |
1917 | next_rq = cpu_rq(cpu); | |
1918 | ||
1919 | /* Make sure the next rq can push to this rq */ | |
1920 | if (next_rq->rt.highest_prio.next < rq->rt.highest_prio.curr) | |
1921 | break; | |
1922 | } | |
1923 | ||
1924 | return cpu; | |
1925 | } | |
1926 | ||
1927 | #define RT_PUSH_IPI_EXECUTING 1 | |
1928 | #define RT_PUSH_IPI_RESTART 2 | |
1929 | ||
1930 | static void tell_cpu_to_push(struct rq *rq) | |
1931 | { | |
1932 | int cpu; | |
1933 | ||
1934 | if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) { | |
1935 | raw_spin_lock(&rq->rt.push_lock); | |
1936 | /* Make sure it's still executing */ | |
1937 | if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) { | |
1938 | /* | |
1939 | * Tell the IPI to restart the loop as things have | |
1940 | * changed since it started. | |
1941 | */ | |
1942 | rq->rt.push_flags |= RT_PUSH_IPI_RESTART; | |
1943 | raw_spin_unlock(&rq->rt.push_lock); | |
1944 | return; | |
1945 | } | |
1946 | raw_spin_unlock(&rq->rt.push_lock); | |
1947 | } | |
1948 | ||
1949 | /* When here, there's no IPI going around */ | |
1950 | ||
1951 | rq->rt.push_cpu = rq->cpu; | |
1952 | cpu = find_next_push_cpu(rq); | |
1953 | if (cpu >= nr_cpu_ids) | |
1954 | return; | |
1955 | ||
1956 | rq->rt.push_flags = RT_PUSH_IPI_EXECUTING; | |
1957 | ||
1958 | irq_work_queue_on(&rq->rt.push_work, cpu); | |
1959 | } | |
1960 | ||
1961 | /* Called from hardirq context */ | |
1962 | static void try_to_push_tasks(void *arg) | |
1963 | { | |
1964 | struct rt_rq *rt_rq = arg; | |
1965 | struct rq *rq, *src_rq; | |
1966 | int this_cpu; | |
1967 | int cpu; | |
1968 | ||
1969 | this_cpu = rt_rq->push_cpu; | |
1970 | ||
1971 | /* Paranoid check */ | |
1972 | BUG_ON(this_cpu != smp_processor_id()); | |
1973 | ||
1974 | rq = cpu_rq(this_cpu); | |
1975 | src_rq = rq_of_rt_rq(rt_rq); | |
1976 | ||
1977 | again: | |
1978 | if (has_pushable_tasks(rq)) { | |
1979 | raw_spin_lock(&rq->lock); | |
1980 | push_rt_task(rq); | |
1981 | raw_spin_unlock(&rq->lock); | |
1982 | } | |
1983 | ||
1984 | /* Pass the IPI to the next rt overloaded queue */ | |
1985 | raw_spin_lock(&rt_rq->push_lock); | |
1986 | /* | |
1987 | * If the source queue changed since the IPI went out, | |
1988 | * we need to restart the search from that CPU again. | |
1989 | */ | |
1990 | if (rt_rq->push_flags & RT_PUSH_IPI_RESTART) { | |
1991 | rt_rq->push_flags &= ~RT_PUSH_IPI_RESTART; | |
1992 | rt_rq->push_cpu = src_rq->cpu; | |
1993 | } | |
1994 | ||
1995 | cpu = find_next_push_cpu(src_rq); | |
1996 | ||
1997 | if (cpu >= nr_cpu_ids) | |
1998 | rt_rq->push_flags &= ~RT_PUSH_IPI_EXECUTING; | |
1999 | raw_spin_unlock(&rt_rq->push_lock); | |
2000 | ||
2001 | if (cpu >= nr_cpu_ids) | |
2002 | return; | |
2003 | ||
2004 | /* | |
2005 | * It is possible that a restart caused this CPU to be | |
2006 | * chosen again. Don't bother with an IPI, just see if we | |
2007 | * have more to push. | |
2008 | */ | |
2009 | if (unlikely(cpu == rq->cpu)) | |
2010 | goto again; | |
2011 | ||
2012 | /* Try the next RT overloaded CPU */ | |
2013 | irq_work_queue_on(&rt_rq->push_work, cpu); | |
2014 | } | |
2015 | ||
2016 | static void push_irq_work_func(struct irq_work *work) | |
2017 | { | |
2018 | struct rt_rq *rt_rq = container_of(work, struct rt_rq, push_work); | |
2019 | ||
2020 | try_to_push_tasks(rt_rq); | |
2021 | } | |
2022 | #endif /* HAVE_RT_PUSH_IPI */ | |
2023 | ||
2024 | static void pull_rt_task(struct rq *this_rq) | |
2025 | { | |
2026 | int this_cpu = this_rq->cpu, cpu; | |
2027 | bool resched = false; | |
2028 | struct task_struct *p; | |
2029 | struct rq *src_rq; | |
2030 | ||
2031 | if (likely(!rt_overloaded(this_rq))) | |
2032 | return; | |
2033 | ||
2034 | /* | |
2035 | * Match the barrier from rt_set_overloaded; this guarantees that if we | |
2036 | * see overloaded we must also see the rto_mask bit. | |
2037 | */ | |
2038 | smp_rmb(); | |
2039 | ||
2040 | #ifdef HAVE_RT_PUSH_IPI | |
2041 | if (sched_feat(RT_PUSH_IPI)) { | |
2042 | tell_cpu_to_push(this_rq); | |
2043 | return; | |
2044 | } | |
2045 | #endif | |
2046 | ||
2047 | for_each_cpu(cpu, this_rq->rd->rto_mask) { | |
2048 | if (this_cpu == cpu) | |
2049 | continue; | |
2050 | ||
2051 | src_rq = cpu_rq(cpu); | |
2052 | ||
2053 | /* | |
2054 | * Don't bother taking the src_rq->lock if the next highest | |
2055 | * task is known to be lower-priority than our current task. | |
2056 | * This may look racy, but if this value is about to go | |
2057 | * logically higher, the src_rq will push this task away. | |
2058 | * And if its going logically lower, we do not care | |
2059 | */ | |
2060 | if (src_rq->rt.highest_prio.next >= | |
2061 | this_rq->rt.highest_prio.curr) | |
2062 | continue; | |
2063 | ||
2064 | /* | |
2065 | * We can potentially drop this_rq's lock in | |
2066 | * double_lock_balance, and another CPU could | |
2067 | * alter this_rq | |
2068 | */ | |
2069 | double_lock_balance(this_rq, src_rq); | |
2070 | ||
2071 | /* | |
2072 | * We can pull only a task, which is pushable | |
2073 | * on its rq, and no others. | |
2074 | */ | |
2075 | p = pick_highest_pushable_task(src_rq, this_cpu); | |
2076 | ||
2077 | /* | |
2078 | * Do we have an RT task that preempts | |
2079 | * the to-be-scheduled task? | |
2080 | */ | |
2081 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { | |
2082 | WARN_ON(p == src_rq->curr); | |
2083 | WARN_ON(!task_on_rq_queued(p)); | |
2084 | ||
2085 | /* | |
2086 | * There's a chance that p is higher in priority | |
2087 | * than what's currently running on its cpu. | |
2088 | * This is just that p is wakeing up and hasn't | |
2089 | * had a chance to schedule. We only pull | |
2090 | * p if it is lower in priority than the | |
2091 | * current task on the run queue | |
2092 | */ | |
2093 | if (p->prio < src_rq->curr->prio) | |
2094 | goto skip; | |
2095 | ||
2096 | resched = true; | |
2097 | ||
2098 | deactivate_task(src_rq, p, 0); | |
2099 | set_task_cpu(p, this_cpu); | |
2100 | activate_task(this_rq, p, 0); | |
2101 | /* | |
2102 | * We continue with the search, just in | |
2103 | * case there's an even higher prio task | |
2104 | * in another runqueue. (low likelihood | |
2105 | * but possible) | |
2106 | */ | |
2107 | } | |
2108 | skip: | |
2109 | double_unlock_balance(this_rq, src_rq); | |
2110 | } | |
2111 | ||
2112 | if (resched) | |
2113 | resched_curr(this_rq); | |
2114 | } | |
2115 | ||
2116 | /* | |
2117 | * If we are not running and we are not going to reschedule soon, we should | |
2118 | * try to push tasks away now | |
2119 | */ | |
2120 | static void task_woken_rt(struct rq *rq, struct task_struct *p) | |
2121 | { | |
2122 | if (!task_running(rq, p) && | |
2123 | !test_tsk_need_resched(rq->curr) && | |
2124 | tsk_nr_cpus_allowed(p) > 1 && | |
2125 | (dl_task(rq->curr) || rt_task(rq->curr)) && | |
2126 | (tsk_nr_cpus_allowed(rq->curr) < 2 || | |
2127 | rq->curr->prio <= p->prio)) | |
2128 | push_rt_tasks(rq); | |
2129 | } | |
2130 | ||
2131 | /* Assumes rq->lock is held */ | |
2132 | static void rq_online_rt(struct rq *rq) | |
2133 | { | |
2134 | if (rq->rt.overloaded) | |
2135 | rt_set_overload(rq); | |
2136 | ||
2137 | __enable_runtime(rq); | |
2138 | ||
2139 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); | |
2140 | } | |
2141 | ||
2142 | /* Assumes rq->lock is held */ | |
2143 | static void rq_offline_rt(struct rq *rq) | |
2144 | { | |
2145 | if (rq->rt.overloaded) | |
2146 | rt_clear_overload(rq); | |
2147 | ||
2148 | __disable_runtime(rq); | |
2149 | ||
2150 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); | |
2151 | } | |
2152 | ||
2153 | /* | |
2154 | * When switch from the rt queue, we bring ourselves to a position | |
2155 | * that we might want to pull RT tasks from other runqueues. | |
2156 | */ | |
2157 | static void switched_from_rt(struct rq *rq, struct task_struct *p) | |
2158 | { | |
2159 | /* | |
2160 | * If there are other RT tasks then we will reschedule | |
2161 | * and the scheduling of the other RT tasks will handle | |
2162 | * the balancing. But if we are the last RT task | |
2163 | * we may need to handle the pulling of RT tasks | |
2164 | * now. | |
2165 | */ | |
2166 | if (!task_on_rq_queued(p) || rq->rt.rt_nr_running) | |
2167 | return; | |
2168 | ||
2169 | queue_pull_task(rq); | |
2170 | } | |
2171 | ||
2172 | void __init init_sched_rt_class(void) | |
2173 | { | |
2174 | unsigned int i; | |
2175 | ||
2176 | for_each_possible_cpu(i) { | |
2177 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), | |
2178 | GFP_KERNEL, cpu_to_node(i)); | |
2179 | } | |
2180 | } | |
2181 | #endif /* CONFIG_SMP */ | |
2182 | ||
2183 | /* | |
2184 | * When switching a task to RT, we may overload the runqueue | |
2185 | * with RT tasks. In this case we try to push them off to | |
2186 | * other runqueues. | |
2187 | */ | |
2188 | static void switched_to_rt(struct rq *rq, struct task_struct *p) | |
2189 | { | |
2190 | /* | |
2191 | * If we are already running, then there's nothing | |
2192 | * that needs to be done. But if we are not running | |
2193 | * we may need to preempt the current running task. | |
2194 | * If that current running task is also an RT task | |
2195 | * then see if we can move to another run queue. | |
2196 | */ | |
2197 | if (task_on_rq_queued(p) && rq->curr != p) { | |
2198 | #ifdef CONFIG_SMP | |
2199 | if (tsk_nr_cpus_allowed(p) > 1 && rq->rt.overloaded) | |
2200 | queue_push_tasks(rq); | |
2201 | #endif /* CONFIG_SMP */ | |
2202 | if (p->prio < rq->curr->prio) | |
2203 | resched_curr(rq); | |
2204 | } | |
2205 | } | |
2206 | ||
2207 | /* | |
2208 | * Priority of the task has changed. This may cause | |
2209 | * us to initiate a push or pull. | |
2210 | */ | |
2211 | static void | |
2212 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
2213 | { | |
2214 | if (!task_on_rq_queued(p)) | |
2215 | return; | |
2216 | ||
2217 | if (rq->curr == p) { | |
2218 | #ifdef CONFIG_SMP | |
2219 | /* | |
2220 | * If our priority decreases while running, we | |
2221 | * may need to pull tasks to this runqueue. | |
2222 | */ | |
2223 | if (oldprio < p->prio) | |
2224 | queue_pull_task(rq); | |
2225 | ||
2226 | /* | |
2227 | * If there's a higher priority task waiting to run | |
2228 | * then reschedule. | |
2229 | */ | |
2230 | if (p->prio > rq->rt.highest_prio.curr) | |
2231 | resched_curr(rq); | |
2232 | #else | |
2233 | /* For UP simply resched on drop of prio */ | |
2234 | if (oldprio < p->prio) | |
2235 | resched_curr(rq); | |
2236 | #endif /* CONFIG_SMP */ | |
2237 | } else { | |
2238 | /* | |
2239 | * This task is not running, but if it is | |
2240 | * greater than the current running task | |
2241 | * then reschedule. | |
2242 | */ | |
2243 | if (p->prio < rq->curr->prio) | |
2244 | resched_curr(rq); | |
2245 | } | |
2246 | } | |
2247 | ||
2248 | static void watchdog(struct rq *rq, struct task_struct *p) | |
2249 | { | |
2250 | unsigned long soft, hard; | |
2251 | ||
2252 | /* max may change after cur was read, this will be fixed next tick */ | |
2253 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
2254 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
2255 | ||
2256 | if (soft != RLIM_INFINITY) { | |
2257 | unsigned long next; | |
2258 | ||
2259 | if (p->rt.watchdog_stamp != jiffies) { | |
2260 | p->rt.timeout++; | |
2261 | p->rt.watchdog_stamp = jiffies; | |
2262 | } | |
2263 | ||
2264 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); | |
2265 | if (p->rt.timeout > next) | |
2266 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; | |
2267 | } | |
2268 | } | |
2269 | ||
2270 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) | |
2271 | { | |
2272 | struct sched_rt_entity *rt_se = &p->rt; | |
2273 | ||
2274 | update_curr_rt(rq); | |
2275 | ||
2276 | watchdog(rq, p); | |
2277 | ||
2278 | /* | |
2279 | * RR tasks need a special form of timeslice management. | |
2280 | * FIFO tasks have no timeslices. | |
2281 | */ | |
2282 | if (p->policy != SCHED_RR) | |
2283 | return; | |
2284 | ||
2285 | if (--p->rt.time_slice) | |
2286 | return; | |
2287 | ||
2288 | p->rt.time_slice = sched_rr_timeslice; | |
2289 | ||
2290 | /* | |
2291 | * Requeue to the end of queue if we (and all of our ancestors) are not | |
2292 | * the only element on the queue | |
2293 | */ | |
2294 | for_each_sched_rt_entity(rt_se) { | |
2295 | if (rt_se->run_list.prev != rt_se->run_list.next) { | |
2296 | requeue_task_rt(rq, p, 0); | |
2297 | resched_curr(rq); | |
2298 | return; | |
2299 | } | |
2300 | } | |
2301 | } | |
2302 | ||
2303 | static void set_curr_task_rt(struct rq *rq) | |
2304 | { | |
2305 | struct task_struct *p = rq->curr; | |
2306 | ||
2307 | p->se.exec_start = rq_clock_task(rq); | |
2308 | ||
2309 | /* The running task is never eligible for pushing */ | |
2310 | dequeue_pushable_task(rq, p); | |
2311 | } | |
2312 | ||
2313 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) | |
2314 | { | |
2315 | /* | |
2316 | * Time slice is 0 for SCHED_FIFO tasks | |
2317 | */ | |
2318 | if (task->policy == SCHED_RR) | |
2319 | return sched_rr_timeslice; | |
2320 | else | |
2321 | return 0; | |
2322 | } | |
2323 | ||
2324 | const struct sched_class rt_sched_class = { | |
2325 | .next = &fair_sched_class, | |
2326 | .enqueue_task = enqueue_task_rt, | |
2327 | .dequeue_task = dequeue_task_rt, | |
2328 | .yield_task = yield_task_rt, | |
2329 | ||
2330 | .check_preempt_curr = check_preempt_curr_rt, | |
2331 | ||
2332 | .pick_next_task = pick_next_task_rt, | |
2333 | .put_prev_task = put_prev_task_rt, | |
2334 | ||
2335 | #ifdef CONFIG_SMP | |
2336 | .select_task_rq = select_task_rq_rt, | |
2337 | ||
2338 | .set_cpus_allowed = set_cpus_allowed_common, | |
2339 | .rq_online = rq_online_rt, | |
2340 | .rq_offline = rq_offline_rt, | |
2341 | .task_woken = task_woken_rt, | |
2342 | .switched_from = switched_from_rt, | |
2343 | #endif | |
2344 | ||
2345 | .set_curr_task = set_curr_task_rt, | |
2346 | .task_tick = task_tick_rt, | |
2347 | ||
2348 | .get_rr_interval = get_rr_interval_rt, | |
2349 | ||
2350 | .prio_changed = prio_changed_rt, | |
2351 | .switched_to = switched_to_rt, | |
2352 | ||
2353 | .update_curr = update_curr_rt, | |
2354 | }; | |
2355 | ||
2356 | #ifdef CONFIG_SCHED_DEBUG | |
2357 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
2358 | ||
2359 | void print_rt_stats(struct seq_file *m, int cpu) | |
2360 | { | |
2361 | rt_rq_iter_t iter; | |
2362 | struct rt_rq *rt_rq; | |
2363 | ||
2364 | rcu_read_lock(); | |
2365 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) | |
2366 | print_rt_rq(m, cpu, rt_rq); | |
2367 | rcu_read_unlock(); | |
2368 | } | |
2369 | #endif /* CONFIG_SCHED_DEBUG */ |