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Commit | Line | Data |
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bb44e5d1 IM |
1 | /* |
2 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR | |
3 | * policies) | |
4 | */ | |
5 | ||
029632fb PZ |
6 | #include "sched.h" |
7 | ||
8 | #include <linux/slab.h> | |
b6366f04 | 9 | #include <linux/irq_work.h> |
029632fb | 10 | |
ce0dbbbb | 11 | int sched_rr_timeslice = RR_TIMESLICE; |
975e155e | 12 | int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE; |
ce0dbbbb | 13 | |
029632fb PZ |
14 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); |
15 | ||
16 | struct rt_bandwidth def_rt_bandwidth; | |
17 | ||
18 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
19 | { | |
20 | struct rt_bandwidth *rt_b = | |
21 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
029632fb | 22 | int idle = 0; |
77a4d1a1 | 23 | int overrun; |
029632fb | 24 | |
77a4d1a1 | 25 | raw_spin_lock(&rt_b->rt_runtime_lock); |
029632fb | 26 | for (;;) { |
77a4d1a1 | 27 | overrun = hrtimer_forward_now(timer, rt_b->rt_period); |
029632fb PZ |
28 | if (!overrun) |
29 | break; | |
30 | ||
77a4d1a1 | 31 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
029632fb | 32 | idle = do_sched_rt_period_timer(rt_b, overrun); |
77a4d1a1 | 33 | raw_spin_lock(&rt_b->rt_runtime_lock); |
029632fb | 34 | } |
4cfafd30 PZ |
35 | if (idle) |
36 | rt_b->rt_period_active = 0; | |
77a4d1a1 | 37 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
029632fb PZ |
38 | |
39 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
40 | } | |
41 | ||
42 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
43 | { | |
44 | rt_b->rt_period = ns_to_ktime(period); | |
45 | rt_b->rt_runtime = runtime; | |
46 | ||
47 | raw_spin_lock_init(&rt_b->rt_runtime_lock); | |
48 | ||
49 | hrtimer_init(&rt_b->rt_period_timer, | |
50 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
51 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
52 | } | |
53 | ||
54 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
55 | { | |
56 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) | |
57 | return; | |
58 | ||
029632fb | 59 | raw_spin_lock(&rt_b->rt_runtime_lock); |
4cfafd30 PZ |
60 | if (!rt_b->rt_period_active) { |
61 | rt_b->rt_period_active = 1; | |
c3a990dc SR |
62 | /* |
63 | * SCHED_DEADLINE updates the bandwidth, as a run away | |
64 | * RT task with a DL task could hog a CPU. But DL does | |
65 | * not reset the period. If a deadline task was running | |
66 | * without an RT task running, it can cause RT tasks to | |
67 | * throttle when they start up. Kick the timer right away | |
68 | * to update the period. | |
69 | */ | |
70 | hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0)); | |
4cfafd30 PZ |
71 | hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED); |
72 | } | |
029632fb PZ |
73 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
74 | } | |
75 | ||
89b41108 | 76 | #if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI) |
b6366f04 SR |
77 | static void push_irq_work_func(struct irq_work *work); |
78 | #endif | |
79 | ||
07c54f7a | 80 | void init_rt_rq(struct rt_rq *rt_rq) |
029632fb PZ |
81 | { |
82 | struct rt_prio_array *array; | |
83 | int i; | |
84 | ||
85 | array = &rt_rq->active; | |
86 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
87 | INIT_LIST_HEAD(array->queue + i); | |
88 | __clear_bit(i, array->bitmap); | |
89 | } | |
90 | /* delimiter for bitsearch: */ | |
91 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
92 | ||
93 | #if defined CONFIG_SMP | |
94 | rt_rq->highest_prio.curr = MAX_RT_PRIO; | |
95 | rt_rq->highest_prio.next = MAX_RT_PRIO; | |
96 | rt_rq->rt_nr_migratory = 0; | |
97 | rt_rq->overloaded = 0; | |
98 | plist_head_init(&rt_rq->pushable_tasks); | |
b6366f04 SR |
99 | |
100 | #ifdef HAVE_RT_PUSH_IPI | |
101 | rt_rq->push_flags = 0; | |
102 | rt_rq->push_cpu = nr_cpu_ids; | |
103 | raw_spin_lock_init(&rt_rq->push_lock); | |
104 | init_irq_work(&rt_rq->push_work, push_irq_work_func); | |
029632fb | 105 | #endif |
b6366f04 | 106 | #endif /* CONFIG_SMP */ |
f4ebcbc0 KT |
107 | /* We start is dequeued state, because no RT tasks are queued */ |
108 | rt_rq->rt_queued = 0; | |
029632fb PZ |
109 | |
110 | rt_rq->rt_time = 0; | |
111 | rt_rq->rt_throttled = 0; | |
112 | rt_rq->rt_runtime = 0; | |
113 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); | |
114 | } | |
115 | ||
8f48894f | 116 | #ifdef CONFIG_RT_GROUP_SCHED |
029632fb PZ |
117 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) |
118 | { | |
119 | hrtimer_cancel(&rt_b->rt_period_timer); | |
120 | } | |
8f48894f PZ |
121 | |
122 | #define rt_entity_is_task(rt_se) (!(rt_se)->my_q) | |
123 | ||
398a153b GH |
124 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
125 | { | |
8f48894f PZ |
126 | #ifdef CONFIG_SCHED_DEBUG |
127 | WARN_ON_ONCE(!rt_entity_is_task(rt_se)); | |
128 | #endif | |
398a153b GH |
129 | return container_of(rt_se, struct task_struct, rt); |
130 | } | |
131 | ||
398a153b GH |
132 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
133 | { | |
134 | return rt_rq->rq; | |
135 | } | |
136 | ||
137 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
138 | { | |
139 | return rt_se->rt_rq; | |
140 | } | |
141 | ||
653d07a6 KT |
142 | static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) |
143 | { | |
144 | struct rt_rq *rt_rq = rt_se->rt_rq; | |
145 | ||
146 | return rt_rq->rq; | |
147 | } | |
148 | ||
029632fb PZ |
149 | void free_rt_sched_group(struct task_group *tg) |
150 | { | |
151 | int i; | |
152 | ||
153 | if (tg->rt_se) | |
154 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
155 | ||
156 | for_each_possible_cpu(i) { | |
157 | if (tg->rt_rq) | |
158 | kfree(tg->rt_rq[i]); | |
159 | if (tg->rt_se) | |
160 | kfree(tg->rt_se[i]); | |
161 | } | |
162 | ||
163 | kfree(tg->rt_rq); | |
164 | kfree(tg->rt_se); | |
165 | } | |
166 | ||
167 | void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, | |
168 | struct sched_rt_entity *rt_se, int cpu, | |
169 | struct sched_rt_entity *parent) | |
170 | { | |
171 | struct rq *rq = cpu_rq(cpu); | |
172 | ||
173 | rt_rq->highest_prio.curr = MAX_RT_PRIO; | |
174 | rt_rq->rt_nr_boosted = 0; | |
175 | rt_rq->rq = rq; | |
176 | rt_rq->tg = tg; | |
177 | ||
178 | tg->rt_rq[cpu] = rt_rq; | |
179 | tg->rt_se[cpu] = rt_se; | |
180 | ||
181 | if (!rt_se) | |
182 | return; | |
183 | ||
184 | if (!parent) | |
185 | rt_se->rt_rq = &rq->rt; | |
186 | else | |
187 | rt_se->rt_rq = parent->my_q; | |
188 | ||
189 | rt_se->my_q = rt_rq; | |
190 | rt_se->parent = parent; | |
191 | INIT_LIST_HEAD(&rt_se->run_list); | |
192 | } | |
193 | ||
194 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
195 | { | |
196 | struct rt_rq *rt_rq; | |
197 | struct sched_rt_entity *rt_se; | |
198 | int i; | |
199 | ||
200 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); | |
201 | if (!tg->rt_rq) | |
202 | goto err; | |
203 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); | |
204 | if (!tg->rt_se) | |
205 | goto err; | |
206 | ||
207 | init_rt_bandwidth(&tg->rt_bandwidth, | |
208 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
209 | ||
210 | for_each_possible_cpu(i) { | |
211 | rt_rq = kzalloc_node(sizeof(struct rt_rq), | |
212 | GFP_KERNEL, cpu_to_node(i)); | |
213 | if (!rt_rq) | |
214 | goto err; | |
215 | ||
216 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), | |
217 | GFP_KERNEL, cpu_to_node(i)); | |
218 | if (!rt_se) | |
219 | goto err_free_rq; | |
220 | ||
07c54f7a | 221 | init_rt_rq(rt_rq); |
029632fb PZ |
222 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
223 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); | |
224 | } | |
225 | ||
226 | return 1; | |
227 | ||
228 | err_free_rq: | |
229 | kfree(rt_rq); | |
230 | err: | |
231 | return 0; | |
232 | } | |
233 | ||
398a153b GH |
234 | #else /* CONFIG_RT_GROUP_SCHED */ |
235 | ||
a1ba4d8b PZ |
236 | #define rt_entity_is_task(rt_se) (1) |
237 | ||
8f48894f PZ |
238 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
239 | { | |
240 | return container_of(rt_se, struct task_struct, rt); | |
241 | } | |
242 | ||
398a153b GH |
243 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
244 | { | |
245 | return container_of(rt_rq, struct rq, rt); | |
246 | } | |
247 | ||
653d07a6 | 248 | static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) |
398a153b GH |
249 | { |
250 | struct task_struct *p = rt_task_of(rt_se); | |
653d07a6 KT |
251 | |
252 | return task_rq(p); | |
253 | } | |
254 | ||
255 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
256 | { | |
257 | struct rq *rq = rq_of_rt_se(rt_se); | |
398a153b GH |
258 | |
259 | return &rq->rt; | |
260 | } | |
261 | ||
029632fb PZ |
262 | void free_rt_sched_group(struct task_group *tg) { } |
263 | ||
264 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
265 | { | |
266 | return 1; | |
267 | } | |
398a153b GH |
268 | #endif /* CONFIG_RT_GROUP_SCHED */ |
269 | ||
4fd29176 | 270 | #ifdef CONFIG_SMP |
84de4274 | 271 | |
8046d680 | 272 | static void pull_rt_task(struct rq *this_rq); |
38033c37 | 273 | |
dc877341 PZ |
274 | static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) |
275 | { | |
276 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
277 | return rq->rt.highest_prio.curr > prev->prio; | |
278 | } | |
279 | ||
637f5085 | 280 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 281 | { |
637f5085 | 282 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 283 | } |
84de4274 | 284 | |
4fd29176 SR |
285 | static inline void rt_set_overload(struct rq *rq) |
286 | { | |
1f11eb6a GH |
287 | if (!rq->online) |
288 | return; | |
289 | ||
c6c4927b | 290 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
291 | /* |
292 | * Make sure the mask is visible before we set | |
293 | * the overload count. That is checked to determine | |
294 | * if we should look at the mask. It would be a shame | |
295 | * if we looked at the mask, but the mask was not | |
296 | * updated yet. | |
7c3f2ab7 PZ |
297 | * |
298 | * Matched by the barrier in pull_rt_task(). | |
4fd29176 | 299 | */ |
7c3f2ab7 | 300 | smp_wmb(); |
637f5085 | 301 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 302 | } |
84de4274 | 303 | |
4fd29176 SR |
304 | static inline void rt_clear_overload(struct rq *rq) |
305 | { | |
1f11eb6a GH |
306 | if (!rq->online) |
307 | return; | |
308 | ||
4fd29176 | 309 | /* the order here really doesn't matter */ |
637f5085 | 310 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 311 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 312 | } |
73fe6aae | 313 | |
398a153b | 314 | static void update_rt_migration(struct rt_rq *rt_rq) |
73fe6aae | 315 | { |
a1ba4d8b | 316 | if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) { |
398a153b GH |
317 | if (!rt_rq->overloaded) { |
318 | rt_set_overload(rq_of_rt_rq(rt_rq)); | |
319 | rt_rq->overloaded = 1; | |
cdc8eb98 | 320 | } |
398a153b GH |
321 | } else if (rt_rq->overloaded) { |
322 | rt_clear_overload(rq_of_rt_rq(rt_rq)); | |
323 | rt_rq->overloaded = 0; | |
637f5085 | 324 | } |
73fe6aae | 325 | } |
4fd29176 | 326 | |
398a153b GH |
327 | static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
328 | { | |
29baa747 PZ |
329 | struct task_struct *p; |
330 | ||
a1ba4d8b PZ |
331 | if (!rt_entity_is_task(rt_se)) |
332 | return; | |
333 | ||
29baa747 | 334 | p = rt_task_of(rt_se); |
a1ba4d8b PZ |
335 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; |
336 | ||
337 | rt_rq->rt_nr_total++; | |
4b53a341 | 338 | if (p->nr_cpus_allowed > 1) |
398a153b GH |
339 | rt_rq->rt_nr_migratory++; |
340 | ||
341 | update_rt_migration(rt_rq); | |
342 | } | |
343 | ||
344 | static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
345 | { | |
29baa747 PZ |
346 | struct task_struct *p; |
347 | ||
a1ba4d8b PZ |
348 | if (!rt_entity_is_task(rt_se)) |
349 | return; | |
350 | ||
29baa747 | 351 | p = rt_task_of(rt_se); |
a1ba4d8b PZ |
352 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; |
353 | ||
354 | rt_rq->rt_nr_total--; | |
4b53a341 | 355 | if (p->nr_cpus_allowed > 1) |
398a153b GH |
356 | rt_rq->rt_nr_migratory--; |
357 | ||
358 | update_rt_migration(rt_rq); | |
359 | } | |
360 | ||
5181f4a4 SR |
361 | static inline int has_pushable_tasks(struct rq *rq) |
362 | { | |
363 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
364 | } | |
365 | ||
fd7a4bed PZ |
366 | static DEFINE_PER_CPU(struct callback_head, rt_push_head); |
367 | static DEFINE_PER_CPU(struct callback_head, rt_pull_head); | |
e3fca9e7 PZ |
368 | |
369 | static void push_rt_tasks(struct rq *); | |
fd7a4bed | 370 | static void pull_rt_task(struct rq *); |
e3fca9e7 PZ |
371 | |
372 | static inline void queue_push_tasks(struct rq *rq) | |
dc877341 | 373 | { |
e3fca9e7 PZ |
374 | if (!has_pushable_tasks(rq)) |
375 | return; | |
376 | ||
fd7a4bed PZ |
377 | queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks); |
378 | } | |
379 | ||
380 | static inline void queue_pull_task(struct rq *rq) | |
381 | { | |
382 | queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task); | |
dc877341 PZ |
383 | } |
384 | ||
917b627d GH |
385 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
386 | { | |
387 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
388 | plist_node_init(&p->pushable_tasks, p->prio); | |
389 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
5181f4a4 SR |
390 | |
391 | /* Update the highest prio pushable task */ | |
392 | if (p->prio < rq->rt.highest_prio.next) | |
393 | rq->rt.highest_prio.next = p->prio; | |
917b627d GH |
394 | } |
395 | ||
396 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
397 | { | |
398 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
917b627d | 399 | |
5181f4a4 SR |
400 | /* Update the new highest prio pushable task */ |
401 | if (has_pushable_tasks(rq)) { | |
402 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
403 | struct task_struct, pushable_tasks); | |
404 | rq->rt.highest_prio.next = p->prio; | |
405 | } else | |
406 | rq->rt.highest_prio.next = MAX_RT_PRIO; | |
bcf08df3 IM |
407 | } |
408 | ||
917b627d GH |
409 | #else |
410 | ||
ceacc2c1 | 411 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
fa85ae24 | 412 | { |
6f505b16 PZ |
413 | } |
414 | ||
ceacc2c1 PZ |
415 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
416 | { | |
417 | } | |
418 | ||
b07430ac | 419 | static inline |
ceacc2c1 PZ |
420 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
421 | { | |
422 | } | |
423 | ||
398a153b | 424 | static inline |
ceacc2c1 PZ |
425 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
426 | { | |
427 | } | |
917b627d | 428 | |
dc877341 PZ |
429 | static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) |
430 | { | |
431 | return false; | |
432 | } | |
433 | ||
8046d680 | 434 | static inline void pull_rt_task(struct rq *this_rq) |
dc877341 | 435 | { |
dc877341 PZ |
436 | } |
437 | ||
e3fca9e7 | 438 | static inline void queue_push_tasks(struct rq *rq) |
dc877341 PZ |
439 | { |
440 | } | |
4fd29176 SR |
441 | #endif /* CONFIG_SMP */ |
442 | ||
f4ebcbc0 KT |
443 | static void enqueue_top_rt_rq(struct rt_rq *rt_rq); |
444 | static void dequeue_top_rt_rq(struct rt_rq *rt_rq); | |
445 | ||
6f505b16 PZ |
446 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
447 | { | |
ff77e468 | 448 | return rt_se->on_rq; |
6f505b16 PZ |
449 | } |
450 | ||
052f1dc7 | 451 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 452 | |
9f0c1e56 | 453 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
454 | { |
455 | if (!rt_rq->tg) | |
9f0c1e56 | 456 | return RUNTIME_INF; |
6f505b16 | 457 | |
ac086bc2 PZ |
458 | return rt_rq->rt_runtime; |
459 | } | |
460 | ||
461 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
462 | { | |
463 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
464 | } |
465 | ||
ec514c48 CX |
466 | typedef struct task_group *rt_rq_iter_t; |
467 | ||
1c09ab0d YZ |
468 | static inline struct task_group *next_task_group(struct task_group *tg) |
469 | { | |
470 | do { | |
471 | tg = list_entry_rcu(tg->list.next, | |
472 | typeof(struct task_group), list); | |
473 | } while (&tg->list != &task_groups && task_group_is_autogroup(tg)); | |
474 | ||
475 | if (&tg->list == &task_groups) | |
476 | tg = NULL; | |
477 | ||
478 | return tg; | |
479 | } | |
480 | ||
481 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
482 | for (iter = container_of(&task_groups, typeof(*iter), list); \ | |
483 | (iter = next_task_group(iter)) && \ | |
484 | (rt_rq = iter->rt_rq[cpu_of(rq)]);) | |
ec514c48 | 485 | |
6f505b16 PZ |
486 | #define for_each_sched_rt_entity(rt_se) \ |
487 | for (; rt_se; rt_se = rt_se->parent) | |
488 | ||
489 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
490 | { | |
491 | return rt_se->my_q; | |
492 | } | |
493 | ||
ff77e468 PZ |
494 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); |
495 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); | |
6f505b16 | 496 | |
9f0c1e56 | 497 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 498 | { |
f6121f4f | 499 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
8875125e | 500 | struct rq *rq = rq_of_rt_rq(rt_rq); |
74b7eb58 YZ |
501 | struct sched_rt_entity *rt_se; |
502 | ||
8875125e | 503 | int cpu = cpu_of(rq); |
0c3b9168 BS |
504 | |
505 | rt_se = rt_rq->tg->rt_se[cpu]; | |
6f505b16 | 506 | |
f6121f4f | 507 | if (rt_rq->rt_nr_running) { |
f4ebcbc0 KT |
508 | if (!rt_se) |
509 | enqueue_top_rt_rq(rt_rq); | |
510 | else if (!on_rt_rq(rt_se)) | |
ff77e468 | 511 | enqueue_rt_entity(rt_se, 0); |
f4ebcbc0 | 512 | |
e864c499 | 513 | if (rt_rq->highest_prio.curr < curr->prio) |
8875125e | 514 | resched_curr(rq); |
6f505b16 PZ |
515 | } |
516 | } | |
517 | ||
9f0c1e56 | 518 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 519 | { |
74b7eb58 | 520 | struct sched_rt_entity *rt_se; |
0c3b9168 | 521 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
74b7eb58 | 522 | |
0c3b9168 | 523 | rt_se = rt_rq->tg->rt_se[cpu]; |
6f505b16 | 524 | |
f4ebcbc0 KT |
525 | if (!rt_se) |
526 | dequeue_top_rt_rq(rt_rq); | |
527 | else if (on_rt_rq(rt_se)) | |
ff77e468 | 528 | dequeue_rt_entity(rt_se, 0); |
6f505b16 PZ |
529 | } |
530 | ||
46383648 KT |
531 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
532 | { | |
533 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
534 | } | |
535 | ||
23b0fdfc PZ |
536 | static int rt_se_boosted(struct sched_rt_entity *rt_se) |
537 | { | |
538 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
539 | struct task_struct *p; | |
540 | ||
541 | if (rt_rq) | |
542 | return !!rt_rq->rt_nr_boosted; | |
543 | ||
544 | p = rt_task_of(rt_se); | |
545 | return p->prio != p->normal_prio; | |
546 | } | |
547 | ||
d0b27fa7 | 548 | #ifdef CONFIG_SMP |
c6c4927b | 549 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 550 | { |
424c93fe | 551 | return this_rq()->rd->span; |
d0b27fa7 | 552 | } |
6f505b16 | 553 | #else |
c6c4927b | 554 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 555 | { |
c6c4927b | 556 | return cpu_online_mask; |
d0b27fa7 PZ |
557 | } |
558 | #endif | |
6f505b16 | 559 | |
d0b27fa7 PZ |
560 | static inline |
561 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 562 | { |
d0b27fa7 PZ |
563 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
564 | } | |
9f0c1e56 | 565 | |
ac086bc2 PZ |
566 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
567 | { | |
568 | return &rt_rq->tg->rt_bandwidth; | |
569 | } | |
570 | ||
55e12e5e | 571 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
572 | |
573 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
574 | { | |
ac086bc2 PZ |
575 | return rt_rq->rt_runtime; |
576 | } | |
577 | ||
578 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
579 | { | |
580 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
581 | } |
582 | ||
ec514c48 CX |
583 | typedef struct rt_rq *rt_rq_iter_t; |
584 | ||
585 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
586 | for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
587 | ||
6f505b16 PZ |
588 | #define for_each_sched_rt_entity(rt_se) \ |
589 | for (; rt_se; rt_se = NULL) | |
590 | ||
591 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
592 | { | |
593 | return NULL; | |
594 | } | |
595 | ||
9f0c1e56 | 596 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 597 | { |
f4ebcbc0 KT |
598 | struct rq *rq = rq_of_rt_rq(rt_rq); |
599 | ||
600 | if (!rt_rq->rt_nr_running) | |
601 | return; | |
602 | ||
603 | enqueue_top_rt_rq(rt_rq); | |
8875125e | 604 | resched_curr(rq); |
6f505b16 PZ |
605 | } |
606 | ||
9f0c1e56 | 607 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 608 | { |
f4ebcbc0 | 609 | dequeue_top_rt_rq(rt_rq); |
6f505b16 PZ |
610 | } |
611 | ||
46383648 KT |
612 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
613 | { | |
614 | return rt_rq->rt_throttled; | |
615 | } | |
616 | ||
c6c4927b | 617 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 618 | { |
c6c4927b | 619 | return cpu_online_mask; |
d0b27fa7 PZ |
620 | } |
621 | ||
622 | static inline | |
623 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
624 | { | |
625 | return &cpu_rq(cpu)->rt; | |
626 | } | |
627 | ||
ac086bc2 PZ |
628 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
629 | { | |
630 | return &def_rt_bandwidth; | |
631 | } | |
632 | ||
55e12e5e | 633 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 634 | |
faa59937 JL |
635 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) |
636 | { | |
637 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
638 | ||
639 | return (hrtimer_active(&rt_b->rt_period_timer) || | |
640 | rt_rq->rt_time < rt_b->rt_runtime); | |
641 | } | |
642 | ||
ac086bc2 | 643 | #ifdef CONFIG_SMP |
78333cdd PZ |
644 | /* |
645 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
646 | */ | |
269b26a5 | 647 | static void do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
648 | { |
649 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
aa7f6730 | 650 | struct root_domain *rd = rq_of_rt_rq(rt_rq)->rd; |
269b26a5 | 651 | int i, weight; |
ac086bc2 PZ |
652 | u64 rt_period; |
653 | ||
c6c4927b | 654 | weight = cpumask_weight(rd->span); |
ac086bc2 | 655 | |
0986b11b | 656 | raw_spin_lock(&rt_b->rt_runtime_lock); |
ac086bc2 | 657 | rt_period = ktime_to_ns(rt_b->rt_period); |
c6c4927b | 658 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
659 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
660 | s64 diff; | |
661 | ||
662 | if (iter == rt_rq) | |
663 | continue; | |
664 | ||
0986b11b | 665 | raw_spin_lock(&iter->rt_runtime_lock); |
78333cdd PZ |
666 | /* |
667 | * Either all rqs have inf runtime and there's nothing to steal | |
668 | * or __disable_runtime() below sets a specific rq to inf to | |
669 | * indicate its been disabled and disalow stealing. | |
670 | */ | |
7def2be1 PZ |
671 | if (iter->rt_runtime == RUNTIME_INF) |
672 | goto next; | |
673 | ||
78333cdd PZ |
674 | /* |
675 | * From runqueues with spare time, take 1/n part of their | |
676 | * spare time, but no more than our period. | |
677 | */ | |
ac086bc2 PZ |
678 | diff = iter->rt_runtime - iter->rt_time; |
679 | if (diff > 0) { | |
58838cf3 | 680 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
681 | if (rt_rq->rt_runtime + diff > rt_period) |
682 | diff = rt_period - rt_rq->rt_runtime; | |
683 | iter->rt_runtime -= diff; | |
684 | rt_rq->rt_runtime += diff; | |
ac086bc2 | 685 | if (rt_rq->rt_runtime == rt_period) { |
0986b11b | 686 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 PZ |
687 | break; |
688 | } | |
689 | } | |
7def2be1 | 690 | next: |
0986b11b | 691 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 | 692 | } |
0986b11b | 693 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
ac086bc2 | 694 | } |
7def2be1 | 695 | |
78333cdd PZ |
696 | /* |
697 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
698 | */ | |
7def2be1 PZ |
699 | static void __disable_runtime(struct rq *rq) |
700 | { | |
701 | struct root_domain *rd = rq->rd; | |
ec514c48 | 702 | rt_rq_iter_t iter; |
7def2be1 PZ |
703 | struct rt_rq *rt_rq; |
704 | ||
705 | if (unlikely(!scheduler_running)) | |
706 | return; | |
707 | ||
ec514c48 | 708 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
709 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
710 | s64 want; | |
711 | int i; | |
712 | ||
0986b11b TG |
713 | raw_spin_lock(&rt_b->rt_runtime_lock); |
714 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
715 | /* |
716 | * Either we're all inf and nobody needs to borrow, or we're | |
717 | * already disabled and thus have nothing to do, or we have | |
718 | * exactly the right amount of runtime to take out. | |
719 | */ | |
7def2be1 PZ |
720 | if (rt_rq->rt_runtime == RUNTIME_INF || |
721 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
722 | goto balanced; | |
0986b11b | 723 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
7def2be1 | 724 | |
78333cdd PZ |
725 | /* |
726 | * Calculate the difference between what we started out with | |
727 | * and what we current have, that's the amount of runtime | |
728 | * we lend and now have to reclaim. | |
729 | */ | |
7def2be1 PZ |
730 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
731 | ||
78333cdd PZ |
732 | /* |
733 | * Greedy reclaim, take back as much as we can. | |
734 | */ | |
c6c4927b | 735 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
736 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
737 | s64 diff; | |
738 | ||
78333cdd PZ |
739 | /* |
740 | * Can't reclaim from ourselves or disabled runqueues. | |
741 | */ | |
f1679d08 | 742 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
743 | continue; |
744 | ||
0986b11b | 745 | raw_spin_lock(&iter->rt_runtime_lock); |
7def2be1 PZ |
746 | if (want > 0) { |
747 | diff = min_t(s64, iter->rt_runtime, want); | |
748 | iter->rt_runtime -= diff; | |
749 | want -= diff; | |
750 | } else { | |
751 | iter->rt_runtime -= want; | |
752 | want -= want; | |
753 | } | |
0986b11b | 754 | raw_spin_unlock(&iter->rt_runtime_lock); |
7def2be1 PZ |
755 | |
756 | if (!want) | |
757 | break; | |
758 | } | |
759 | ||
0986b11b | 760 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
78333cdd PZ |
761 | /* |
762 | * We cannot be left wanting - that would mean some runtime | |
763 | * leaked out of the system. | |
764 | */ | |
7def2be1 PZ |
765 | BUG_ON(want); |
766 | balanced: | |
78333cdd PZ |
767 | /* |
768 | * Disable all the borrow logic by pretending we have inf | |
769 | * runtime - in which case borrowing doesn't make sense. | |
770 | */ | |
7def2be1 | 771 | rt_rq->rt_runtime = RUNTIME_INF; |
a4c96ae3 | 772 | rt_rq->rt_throttled = 0; |
0986b11b TG |
773 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
774 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
99b62567 KT |
775 | |
776 | /* Make rt_rq available for pick_next_task() */ | |
777 | sched_rt_rq_enqueue(rt_rq); | |
7def2be1 PZ |
778 | } |
779 | } | |
780 | ||
7def2be1 PZ |
781 | static void __enable_runtime(struct rq *rq) |
782 | { | |
ec514c48 | 783 | rt_rq_iter_t iter; |
7def2be1 PZ |
784 | struct rt_rq *rt_rq; |
785 | ||
786 | if (unlikely(!scheduler_running)) | |
787 | return; | |
788 | ||
78333cdd PZ |
789 | /* |
790 | * Reset each runqueue's bandwidth settings | |
791 | */ | |
ec514c48 | 792 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
793 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
794 | ||
0986b11b TG |
795 | raw_spin_lock(&rt_b->rt_runtime_lock); |
796 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
7def2be1 PZ |
797 | rt_rq->rt_runtime = rt_b->rt_runtime; |
798 | rt_rq->rt_time = 0; | |
baf25731 | 799 | rt_rq->rt_throttled = 0; |
0986b11b TG |
800 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
801 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
802 | } |
803 | } | |
804 | ||
269b26a5 | 805 | static void balance_runtime(struct rt_rq *rt_rq) |
eff6549b | 806 | { |
4a6184ce | 807 | if (!sched_feat(RT_RUNTIME_SHARE)) |
269b26a5 | 808 | return; |
4a6184ce | 809 | |
eff6549b | 810 | if (rt_rq->rt_time > rt_rq->rt_runtime) { |
0986b11b | 811 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
269b26a5 | 812 | do_balance_runtime(rt_rq); |
0986b11b | 813 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b | 814 | } |
eff6549b | 815 | } |
55e12e5e | 816 | #else /* !CONFIG_SMP */ |
269b26a5 | 817 | static inline void balance_runtime(struct rt_rq *rt_rq) {} |
55e12e5e | 818 | #endif /* CONFIG_SMP */ |
ac086bc2 | 819 | |
eff6549b PZ |
820 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
821 | { | |
42c62a58 | 822 | int i, idle = 1, throttled = 0; |
c6c4927b | 823 | const struct cpumask *span; |
eff6549b | 824 | |
eff6549b | 825 | span = sched_rt_period_mask(); |
e221d028 MG |
826 | #ifdef CONFIG_RT_GROUP_SCHED |
827 | /* | |
828 | * FIXME: isolated CPUs should really leave the root task group, | |
829 | * whether they are isolcpus or were isolated via cpusets, lest | |
830 | * the timer run on a CPU which does not service all runqueues, | |
831 | * potentially leaving other CPUs indefinitely throttled. If | |
832 | * isolation is really required, the user will turn the throttle | |
833 | * off to kill the perturbations it causes anyway. Meanwhile, | |
834 | * this maintains functionality for boot and/or troubleshooting. | |
835 | */ | |
836 | if (rt_b == &root_task_group.rt_bandwidth) | |
837 | span = cpu_online_mask; | |
838 | #endif | |
c6c4927b | 839 | for_each_cpu(i, span) { |
eff6549b PZ |
840 | int enqueue = 0; |
841 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
842 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
843 | ||
05fa785c | 844 | raw_spin_lock(&rq->lock); |
eff6549b PZ |
845 | if (rt_rq->rt_time) { |
846 | u64 runtime; | |
847 | ||
0986b11b | 848 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
849 | if (rt_rq->rt_throttled) |
850 | balance_runtime(rt_rq); | |
851 | runtime = rt_rq->rt_runtime; | |
852 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
853 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
854 | rt_rq->rt_throttled = 0; | |
855 | enqueue = 1; | |
61eadef6 MG |
856 | |
857 | /* | |
9edfbfed PZ |
858 | * When we're idle and a woken (rt) task is |
859 | * throttled check_preempt_curr() will set | |
860 | * skip_update and the time between the wakeup | |
861 | * and this unthrottle will get accounted as | |
862 | * 'runtime'. | |
61eadef6 MG |
863 | */ |
864 | if (rt_rq->rt_nr_running && rq->curr == rq->idle) | |
9edfbfed | 865 | rq_clock_skip_update(rq, false); |
eff6549b PZ |
866 | } |
867 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
868 | idle = 0; | |
0986b11b | 869 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
0c3b9168 | 870 | } else if (rt_rq->rt_nr_running) { |
6c3df255 | 871 | idle = 0; |
0c3b9168 BS |
872 | if (!rt_rq_throttled(rt_rq)) |
873 | enqueue = 1; | |
874 | } | |
42c62a58 PZ |
875 | if (rt_rq->rt_throttled) |
876 | throttled = 1; | |
eff6549b PZ |
877 | |
878 | if (enqueue) | |
879 | sched_rt_rq_enqueue(rt_rq); | |
05fa785c | 880 | raw_spin_unlock(&rq->lock); |
eff6549b PZ |
881 | } |
882 | ||
42c62a58 PZ |
883 | if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) |
884 | return 1; | |
885 | ||
eff6549b PZ |
886 | return idle; |
887 | } | |
ac086bc2 | 888 | |
6f505b16 PZ |
889 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
890 | { | |
052f1dc7 | 891 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
892 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
893 | ||
894 | if (rt_rq) | |
e864c499 | 895 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
896 | #endif |
897 | ||
898 | return rt_task_of(rt_se)->prio; | |
899 | } | |
900 | ||
9f0c1e56 | 901 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 902 | { |
9f0c1e56 | 903 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 904 | |
fa85ae24 | 905 | if (rt_rq->rt_throttled) |
23b0fdfc | 906 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 907 | |
5b680fd6 | 908 | if (runtime >= sched_rt_period(rt_rq)) |
ac086bc2 PZ |
909 | return 0; |
910 | ||
b79f3833 PZ |
911 | balance_runtime(rt_rq); |
912 | runtime = sched_rt_runtime(rt_rq); | |
913 | if (runtime == RUNTIME_INF) | |
914 | return 0; | |
ac086bc2 | 915 | |
9f0c1e56 | 916 | if (rt_rq->rt_time > runtime) { |
7abc63b1 PZ |
917 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
918 | ||
919 | /* | |
920 | * Don't actually throttle groups that have no runtime assigned | |
921 | * but accrue some time due to boosting. | |
922 | */ | |
923 | if (likely(rt_b->rt_runtime)) { | |
924 | rt_rq->rt_throttled = 1; | |
c224815d | 925 | printk_deferred_once("sched: RT throttling activated\n"); |
7abc63b1 PZ |
926 | } else { |
927 | /* | |
928 | * In case we did anyway, make it go away, | |
929 | * replenishment is a joke, since it will replenish us | |
930 | * with exactly 0 ns. | |
931 | */ | |
932 | rt_rq->rt_time = 0; | |
933 | } | |
934 | ||
23b0fdfc | 935 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 936 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
937 | return 1; |
938 | } | |
fa85ae24 PZ |
939 | } |
940 | ||
941 | return 0; | |
942 | } | |
943 | ||
bb44e5d1 IM |
944 | /* |
945 | * Update the current task's runtime statistics. Skip current tasks that | |
946 | * are not in our scheduling class. | |
947 | */ | |
a9957449 | 948 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
949 | { |
950 | struct task_struct *curr = rq->curr; | |
6f505b16 | 951 | struct sched_rt_entity *rt_se = &curr->rt; |
bb44e5d1 IM |
952 | u64 delta_exec; |
953 | ||
06c3bc65 | 954 | if (curr->sched_class != &rt_sched_class) |
bb44e5d1 IM |
955 | return; |
956 | ||
78becc27 | 957 | delta_exec = rq_clock_task(rq) - curr->se.exec_start; |
fc79e240 KT |
958 | if (unlikely((s64)delta_exec <= 0)) |
959 | return; | |
6cfb0d5d | 960 | |
58919e83 | 961 | /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ |
12bde33d | 962 | cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT); |
594dd290 | 963 | |
42c62a58 PZ |
964 | schedstat_set(curr->se.statistics.exec_max, |
965 | max(curr->se.statistics.exec_max, delta_exec)); | |
bb44e5d1 IM |
966 | |
967 | curr->se.sum_exec_runtime += delta_exec; | |
f06febc9 FM |
968 | account_group_exec_runtime(curr, delta_exec); |
969 | ||
78becc27 | 970 | curr->se.exec_start = rq_clock_task(rq); |
d842de87 | 971 | cpuacct_charge(curr, delta_exec); |
fa85ae24 | 972 | |
e9e9250b PZ |
973 | sched_rt_avg_update(rq, delta_exec); |
974 | ||
0b148fa0 PZ |
975 | if (!rt_bandwidth_enabled()) |
976 | return; | |
977 | ||
354d60c2 | 978 | for_each_sched_rt_entity(rt_se) { |
0b07939c | 979 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
354d60c2 | 980 | |
cc2991cf | 981 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
0986b11b | 982 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf PZ |
983 | rt_rq->rt_time += delta_exec; |
984 | if (sched_rt_runtime_exceeded(rt_rq)) | |
8875125e | 985 | resched_curr(rq); |
0986b11b | 986 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
cc2991cf | 987 | } |
354d60c2 | 988 | } |
bb44e5d1 IM |
989 | } |
990 | ||
f4ebcbc0 KT |
991 | static void |
992 | dequeue_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 | ||
72465447 | 1003 | sub_nr_running(rq, rt_rq->rt_nr_running); |
f4ebcbc0 KT |
1004 | rt_rq->rt_queued = 0; |
1005 | } | |
1006 | ||
1007 | static void | |
1008 | enqueue_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 | ||
72465447 | 1019 | add_nr_running(rq, rt_rq->rt_nr_running); |
f4ebcbc0 KT |
1020 | rt_rq->rt_queued = 1; |
1021 | } | |
1022 | ||
398a153b | 1023 | #if defined CONFIG_SMP |
e864c499 | 1024 | |
398a153b GH |
1025 | static void |
1026 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 1027 | { |
4d984277 | 1028 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 1029 | |
757dfcaa KT |
1030 | #ifdef CONFIG_RT_GROUP_SCHED |
1031 | /* | |
1032 | * Change rq's cpupri only if rt_rq is the top queue. | |
1033 | */ | |
1034 | if (&rq->rt != rt_rq) | |
1035 | return; | |
1036 | #endif | |
5181f4a4 SR |
1037 | if (rq->online && prio < prev_prio) |
1038 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); | |
398a153b | 1039 | } |
73fe6aae | 1040 | |
398a153b GH |
1041 | static void |
1042 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
1043 | { | |
1044 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 1045 | |
757dfcaa KT |
1046 | #ifdef CONFIG_RT_GROUP_SCHED |
1047 | /* | |
1048 | * Change rq's cpupri only if rt_rq is the top queue. | |
1049 | */ | |
1050 | if (&rq->rt != rt_rq) | |
1051 | return; | |
1052 | #endif | |
398a153b GH |
1053 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) |
1054 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
1055 | } |
1056 | ||
398a153b GH |
1057 | #else /* CONFIG_SMP */ |
1058 | ||
6f505b16 | 1059 | static inline |
398a153b GH |
1060 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
1061 | static inline | |
1062 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
1063 | ||
1064 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 1065 | |
052f1dc7 | 1066 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
1067 | static void |
1068 | inc_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 | ||
1078 | static void | |
1079 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
1080 | { | |
1081 | int prev_prio = rt_rq->highest_prio.curr; | |
1082 | ||
6f505b16 | 1083 | if (rt_rq->rt_nr_running) { |
764a9d6f | 1084 | |
398a153b | 1085 | WARN_ON(prio < prev_prio); |
764a9d6f | 1086 | |
e864c499 | 1087 | /* |
398a153b GH |
1088 | * This may have been our highest task, and therefore |
1089 | * we may have some recomputation to do | |
e864c499 | 1090 | */ |
398a153b | 1091 | if (prio == prev_prio) { |
e864c499 GH |
1092 | struct rt_prio_array *array = &rt_rq->active; |
1093 | ||
1094 | rt_rq->highest_prio.curr = | |
764a9d6f | 1095 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
1096 | } |
1097 | ||
764a9d6f | 1098 | } else |
e864c499 | 1099 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
73fe6aae | 1100 | |
398a153b GH |
1101 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
1102 | } | |
1f11eb6a | 1103 | |
398a153b GH |
1104 | #else |
1105 | ||
1106 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1107 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1108 | ||
1109 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 1110 | |
052f1dc7 | 1111 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
1112 | |
1113 | static void | |
1114 | inc_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 | ||
1123 | static void | |
1124 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1125 | { | |
23b0fdfc PZ |
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); | |
398a153b GH |
1130 | } |
1131 | ||
1132 | #else /* CONFIG_RT_GROUP_SCHED */ | |
1133 | ||
1134 | static void | |
1135 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1136 | { | |
1137 | start_rt_bandwidth(&def_rt_bandwidth); | |
1138 | } | |
1139 | ||
1140 | static inline | |
1141 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
1142 | ||
1143 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
1144 | ||
22abdef3 KT |
1145 | static inline |
1146 | unsigned 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 | ||
01d36d0a FW |
1156 | static inline |
1157 | unsigned 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 | ||
398a153b GH |
1170 | static inline |
1171 | void 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)); | |
22abdef3 | 1176 | rt_rq->rt_nr_running += rt_se_nr_running(rt_se); |
01d36d0a | 1177 | rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se); |
398a153b GH |
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 | ||
1184 | static inline | |
1185 | void 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); | |
22abdef3 | 1189 | rt_rq->rt_nr_running -= rt_se_nr_running(rt_se); |
01d36d0a | 1190 | rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se); |
398a153b GH |
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); | |
63489e45 SR |
1195 | } |
1196 | ||
ff77e468 PZ |
1197 | /* |
1198 | * Change rt_se->run_list location unless SAVE && !MOVE | |
1199 | * | |
1200 | * assumes ENQUEUE/DEQUEUE flags match | |
1201 | */ | |
1202 | static 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 | ||
1210 | static 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 | ||
1220 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) | |
bb44e5d1 | 1221 | { |
6f505b16 PZ |
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); | |
20b6331b | 1225 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 1226 | |
ad2a3f13 PZ |
1227 | /* |
1228 | * Don't enqueue the group if its throttled, or when empty. | |
1229 | * The latter is a consequence of the former when a child group | |
1230 | * get throttled and the current group doesn't have any other | |
1231 | * active members. | |
1232 | */ | |
ff77e468 PZ |
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); | |
6f505b16 | 1236 | return; |
ff77e468 | 1237 | } |
63489e45 | 1238 | |
ff77e468 PZ |
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; | |
78f2c7db | 1250 | |
6f505b16 PZ |
1251 | inc_rt_tasks(rt_se, rt_rq); |
1252 | } | |
1253 | ||
ff77e468 | 1254 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
6f505b16 PZ |
1255 | { |
1256 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
1257 | struct rt_prio_array *array = &rt_rq->active; | |
1258 | ||
ff77e468 PZ |
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; | |
6f505b16 PZ |
1264 | |
1265 | dec_rt_tasks(rt_se, rt_rq); | |
1266 | } | |
1267 | ||
1268 | /* | |
1269 | * Because the prio of an upper entry depends on the lower | |
1270 | * entries, we must remove entries top - down. | |
6f505b16 | 1271 | */ |
ff77e468 | 1272 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags) |
6f505b16 | 1273 | { |
ad2a3f13 | 1274 | struct sched_rt_entity *back = NULL; |
6f505b16 | 1275 | |
58d6c2d7 PZ |
1276 | for_each_sched_rt_entity(rt_se) { |
1277 | rt_se->back = back; | |
1278 | back = rt_se; | |
1279 | } | |
1280 | ||
f4ebcbc0 KT |
1281 | dequeue_top_rt_rq(rt_rq_of_se(back)); |
1282 | ||
58d6c2d7 PZ |
1283 | for (rt_se = back; rt_se; rt_se = rt_se->back) { |
1284 | if (on_rt_rq(rt_se)) | |
ff77e468 | 1285 | __dequeue_rt_entity(rt_se, flags); |
ad2a3f13 PZ |
1286 | } |
1287 | } | |
1288 | ||
ff77e468 | 1289 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
ad2a3f13 | 1290 | { |
f4ebcbc0 KT |
1291 | struct rq *rq = rq_of_rt_se(rt_se); |
1292 | ||
ff77e468 | 1293 | dequeue_rt_stack(rt_se, flags); |
ad2a3f13 | 1294 | for_each_sched_rt_entity(rt_se) |
ff77e468 | 1295 | __enqueue_rt_entity(rt_se, flags); |
f4ebcbc0 | 1296 | enqueue_top_rt_rq(&rq->rt); |
ad2a3f13 PZ |
1297 | } |
1298 | ||
ff77e468 | 1299 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
ad2a3f13 | 1300 | { |
f4ebcbc0 KT |
1301 | struct rq *rq = rq_of_rt_se(rt_se); |
1302 | ||
ff77e468 | 1303 | dequeue_rt_stack(rt_se, flags); |
ad2a3f13 PZ |
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) | |
ff77e468 | 1309 | __enqueue_rt_entity(rt_se, flags); |
58d6c2d7 | 1310 | } |
f4ebcbc0 | 1311 | enqueue_top_rt_rq(&rq->rt); |
bb44e5d1 IM |
1312 | } |
1313 | ||
1314 | /* | |
1315 | * Adding/removing a task to/from a priority array: | |
1316 | */ | |
ea87bb78 | 1317 | static void |
371fd7e7 | 1318 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
6f505b16 PZ |
1319 | { |
1320 | struct sched_rt_entity *rt_se = &p->rt; | |
1321 | ||
371fd7e7 | 1322 | if (flags & ENQUEUE_WAKEUP) |
6f505b16 PZ |
1323 | rt_se->timeout = 0; |
1324 | ||
ff77e468 | 1325 | enqueue_rt_entity(rt_se, flags); |
c09595f6 | 1326 | |
4b53a341 | 1327 | if (!task_current(rq, p) && p->nr_cpus_allowed > 1) |
917b627d | 1328 | enqueue_pushable_task(rq, p); |
6f505b16 PZ |
1329 | } |
1330 | ||
371fd7e7 | 1331 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1332 | { |
6f505b16 | 1333 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 1334 | |
f1e14ef6 | 1335 | update_curr_rt(rq); |
ff77e468 | 1336 | dequeue_rt_entity(rt_se, flags); |
c09595f6 | 1337 | |
917b627d | 1338 | dequeue_pushable_task(rq, p); |
bb44e5d1 IM |
1339 | } |
1340 | ||
1341 | /* | |
60686317 RW |
1342 | * Put task to the head or the end of the run list without the overhead of |
1343 | * dequeue followed by enqueue. | |
bb44e5d1 | 1344 | */ |
7ebefa8c DA |
1345 | static void |
1346 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 1347 | { |
1cdad715 | 1348 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
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); | |
1cdad715 | 1356 | } |
6f505b16 PZ |
1357 | } |
1358 | ||
7ebefa8c | 1359 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 1360 | { |
6f505b16 PZ |
1361 | struct sched_rt_entity *rt_se = &p->rt; |
1362 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1363 | |
6f505b16 PZ |
1364 | for_each_sched_rt_entity(rt_se) { |
1365 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 1366 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 1367 | } |
bb44e5d1 IM |
1368 | } |
1369 | ||
6f505b16 | 1370 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 1371 | { |
7ebefa8c | 1372 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
1373 | } |
1374 | ||
e7693a36 | 1375 | #ifdef CONFIG_SMP |
318e0893 GH |
1376 | static int find_lowest_rq(struct task_struct *task); |
1377 | ||
0017d735 | 1378 | static int |
ac66f547 | 1379 | select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags) |
e7693a36 | 1380 | { |
7608dec2 PZ |
1381 | struct task_struct *curr; |
1382 | struct rq *rq; | |
c37495fd SR |
1383 | |
1384 | /* For anything but wake ups, just return the task_cpu */ | |
1385 | if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK) | |
1386 | goto out; | |
1387 | ||
7608dec2 PZ |
1388 | rq = cpu_rq(cpu); |
1389 | ||
1390 | rcu_read_lock(); | |
316c1608 | 1391 | curr = READ_ONCE(rq->curr); /* unlocked access */ |
7608dec2 | 1392 | |
318e0893 | 1393 | /* |
7608dec2 | 1394 | * If the current task on @p's runqueue is an RT task, then |
e1f47d89 SR |
1395 | * try to see if we can wake this RT task up on another |
1396 | * runqueue. Otherwise simply start this RT task | |
1397 | * on its current runqueue. | |
1398 | * | |
43fa5460 SR |
1399 | * We want to avoid overloading runqueues. If the woken |
1400 | * task is a higher priority, then it will stay on this CPU | |
1401 | * and the lower prio task should be moved to another CPU. | |
1402 | * Even though this will probably make the lower prio task | |
1403 | * lose its cache, we do not want to bounce a higher task | |
1404 | * around just because it gave up its CPU, perhaps for a | |
1405 | * lock? | |
1406 | * | |
1407 | * For equal prio tasks, we just let the scheduler sort it out. | |
7608dec2 PZ |
1408 | * |
1409 | * Otherwise, just let it ride on the affined RQ and the | |
1410 | * post-schedule router will push the preempted task away | |
1411 | * | |
1412 | * This test is optimistic, if we get it wrong the load-balancer | |
1413 | * will have to sort it out. | |
318e0893 | 1414 | */ |
7608dec2 | 1415 | if (curr && unlikely(rt_task(curr)) && |
4b53a341 | 1416 | (curr->nr_cpus_allowed < 2 || |
6bfa687c | 1417 | curr->prio <= p->prio)) { |
7608dec2 | 1418 | int target = find_lowest_rq(p); |
318e0893 | 1419 | |
80e3d87b TC |
1420 | /* |
1421 | * Don't bother moving it if the destination CPU is | |
1422 | * not running a lower priority task. | |
1423 | */ | |
1424 | if (target != -1 && | |
1425 | p->prio < cpu_rq(target)->rt.highest_prio.curr) | |
7608dec2 | 1426 | cpu = target; |
318e0893 | 1427 | } |
7608dec2 | 1428 | rcu_read_unlock(); |
318e0893 | 1429 | |
c37495fd | 1430 | out: |
7608dec2 | 1431 | return cpu; |
e7693a36 | 1432 | } |
7ebefa8c DA |
1433 | |
1434 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1435 | { | |
308a623a WL |
1436 | /* |
1437 | * Current can't be migrated, useless to reschedule, | |
1438 | * let's hope p can move out. | |
1439 | */ | |
4b53a341 | 1440 | if (rq->curr->nr_cpus_allowed == 1 || |
308a623a | 1441 | !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) |
7ebefa8c DA |
1442 | return; |
1443 | ||
308a623a WL |
1444 | /* |
1445 | * p is migratable, so let's not schedule it and | |
1446 | * see if it is pushed or pulled somewhere else. | |
1447 | */ | |
4b53a341 | 1448 | if (p->nr_cpus_allowed != 1 |
13b8bd0a RR |
1449 | && cpupri_find(&rq->rd->cpupri, p, NULL)) |
1450 | return; | |
24600ce8 | 1451 | |
7ebefa8c DA |
1452 | /* |
1453 | * There appears to be other cpus that can accept | |
1454 | * current and none to run 'p', so lets reschedule | |
1455 | * to try and push current away: | |
1456 | */ | |
1457 | requeue_task_rt(rq, p, 1); | |
8875125e | 1458 | resched_curr(rq); |
7ebefa8c DA |
1459 | } |
1460 | ||
e7693a36 GH |
1461 | #endif /* CONFIG_SMP */ |
1462 | ||
bb44e5d1 IM |
1463 | /* |
1464 | * Preempt the current task with a newly woken task if needed: | |
1465 | */ | |
7d478721 | 1466 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1467 | { |
45c01e82 | 1468 | if (p->prio < rq->curr->prio) { |
8875125e | 1469 | resched_curr(rq); |
45c01e82 GH |
1470 | return; |
1471 | } | |
1472 | ||
1473 | #ifdef CONFIG_SMP | |
1474 | /* | |
1475 | * If: | |
1476 | * | |
1477 | * - the newly woken task is of equal priority to the current task | |
1478 | * - the newly woken task is non-migratable while current is migratable | |
1479 | * - current will be preempted on the next reschedule | |
1480 | * | |
1481 | * we should check to see if current can readily move to a different | |
1482 | * cpu. If so, we will reschedule to allow the push logic to try | |
1483 | * to move current somewhere else, making room for our non-migratable | |
1484 | * task. | |
1485 | */ | |
8dd0de8b | 1486 | if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) |
7ebefa8c | 1487 | check_preempt_equal_prio(rq, p); |
45c01e82 | 1488 | #endif |
bb44e5d1 IM |
1489 | } |
1490 | ||
6f505b16 PZ |
1491 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
1492 | struct rt_rq *rt_rq) | |
bb44e5d1 | 1493 | { |
6f505b16 PZ |
1494 | struct rt_prio_array *array = &rt_rq->active; |
1495 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1496 | struct list_head *queue; |
1497 | int idx; | |
1498 | ||
1499 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1500 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1501 | |
1502 | queue = array->queue + idx; | |
6f505b16 | 1503 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1504 | |
6f505b16 PZ |
1505 | return next; |
1506 | } | |
bb44e5d1 | 1507 | |
917b627d | 1508 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1509 | { |
1510 | struct sched_rt_entity *rt_se; | |
1511 | struct task_struct *p; | |
606dba2e | 1512 | struct rt_rq *rt_rq = &rq->rt; |
6f505b16 PZ |
1513 | |
1514 | do { | |
1515 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
326587b8 | 1516 | BUG_ON(!rt_se); |
6f505b16 PZ |
1517 | rt_rq = group_rt_rq(rt_se); |
1518 | } while (rt_rq); | |
1519 | ||
1520 | p = rt_task_of(rt_se); | |
78becc27 | 1521 | p->se.exec_start = rq_clock_task(rq); |
917b627d GH |
1522 | |
1523 | return p; | |
1524 | } | |
1525 | ||
606dba2e | 1526 | static struct task_struct * |
d8ac8971 | 1527 | pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) |
917b627d | 1528 | { |
606dba2e PZ |
1529 | struct task_struct *p; |
1530 | struct rt_rq *rt_rq = &rq->rt; | |
1531 | ||
37e117c0 | 1532 | if (need_pull_rt_task(rq, prev)) { |
cbce1a68 PZ |
1533 | /* |
1534 | * This is OK, because current is on_cpu, which avoids it being | |
1535 | * picked for load-balance and preemption/IRQs are still | |
1536 | * disabled avoiding further scheduler activity on it and we're | |
1537 | * being very careful to re-start the picking loop. | |
1538 | */ | |
d8ac8971 | 1539 | rq_unpin_lock(rq, rf); |
38033c37 | 1540 | pull_rt_task(rq); |
d8ac8971 | 1541 | rq_repin_lock(rq, rf); |
37e117c0 PZ |
1542 | /* |
1543 | * pull_rt_task() can drop (and re-acquire) rq->lock; this | |
a1d9a323 KT |
1544 | * means a dl or stop task can slip in, in which case we need |
1545 | * to re-start task selection. | |
37e117c0 | 1546 | */ |
da0c1e65 | 1547 | if (unlikely((rq->stop && task_on_rq_queued(rq->stop)) || |
a1d9a323 | 1548 | rq->dl.dl_nr_running)) |
37e117c0 PZ |
1549 | return RETRY_TASK; |
1550 | } | |
38033c37 | 1551 | |
734ff2a7 KT |
1552 | /* |
1553 | * We may dequeue prev's rt_rq in put_prev_task(). | |
1554 | * So, we update time before rt_nr_running check. | |
1555 | */ | |
1556 | if (prev->sched_class == &rt_sched_class) | |
1557 | update_curr_rt(rq); | |
1558 | ||
f4ebcbc0 | 1559 | if (!rt_rq->rt_queued) |
606dba2e PZ |
1560 | return NULL; |
1561 | ||
3f1d2a31 | 1562 | put_prev_task(rq, prev); |
606dba2e PZ |
1563 | |
1564 | p = _pick_next_task_rt(rq); | |
917b627d GH |
1565 | |
1566 | /* The running task is never eligible for pushing */ | |
f3f1768f | 1567 | dequeue_pushable_task(rq, p); |
917b627d | 1568 | |
e3fca9e7 | 1569 | queue_push_tasks(rq); |
3f029d3c | 1570 | |
6f505b16 | 1571 | return p; |
bb44e5d1 IM |
1572 | } |
1573 | ||
31ee529c | 1574 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1575 | { |
f1e14ef6 | 1576 | update_curr_rt(rq); |
917b627d GH |
1577 | |
1578 | /* | |
1579 | * The previous task needs to be made eligible for pushing | |
1580 | * if it is still active | |
1581 | */ | |
4b53a341 | 1582 | if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1) |
917b627d | 1583 | enqueue_pushable_task(rq, p); |
bb44e5d1 IM |
1584 | } |
1585 | ||
681f3e68 | 1586 | #ifdef CONFIG_SMP |
6f505b16 | 1587 | |
e8fa1362 SR |
1588 | /* Only try algorithms three times */ |
1589 | #define RT_MAX_TRIES 3 | |
1590 | ||
f65eda4f SR |
1591 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1592 | { | |
1593 | if (!task_running(rq, p) && | |
0c98d344 | 1594 | cpumask_test_cpu(cpu, &p->cpus_allowed)) |
f65eda4f SR |
1595 | return 1; |
1596 | return 0; | |
1597 | } | |
1598 | ||
e23ee747 KT |
1599 | /* |
1600 | * Return the highest pushable rq's task, which is suitable to be executed | |
1601 | * on the cpu, NULL otherwise | |
1602 | */ | |
1603 | static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu) | |
e8fa1362 | 1604 | { |
e23ee747 KT |
1605 | struct plist_head *head = &rq->rt.pushable_tasks; |
1606 | struct task_struct *p; | |
3d07467b | 1607 | |
e23ee747 KT |
1608 | if (!has_pushable_tasks(rq)) |
1609 | return NULL; | |
3d07467b | 1610 | |
e23ee747 KT |
1611 | plist_for_each_entry(p, head, pushable_tasks) { |
1612 | if (pick_rt_task(rq, p, cpu)) | |
1613 | return p; | |
f65eda4f SR |
1614 | } |
1615 | ||
e23ee747 | 1616 | return NULL; |
e8fa1362 SR |
1617 | } |
1618 | ||
0e3900e6 | 1619 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1620 | |
6e1254d2 GH |
1621 | static int find_lowest_rq(struct task_struct *task) |
1622 | { | |
1623 | struct sched_domain *sd; | |
4ba29684 | 1624 | struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask); |
6e1254d2 GH |
1625 | int this_cpu = smp_processor_id(); |
1626 | int cpu = task_cpu(task); | |
06f90dbd | 1627 | |
0da938c4 SR |
1628 | /* Make sure the mask is initialized first */ |
1629 | if (unlikely(!lowest_mask)) | |
1630 | return -1; | |
1631 | ||
4b53a341 | 1632 | if (task->nr_cpus_allowed == 1) |
6e0534f2 | 1633 | return -1; /* No other targets possible */ |
6e1254d2 | 1634 | |
6e0534f2 GH |
1635 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
1636 | return -1; /* No targets found */ | |
6e1254d2 GH |
1637 | |
1638 | /* | |
1639 | * At this point we have built a mask of cpus representing the | |
1640 | * lowest priority tasks in the system. Now we want to elect | |
1641 | * the best one based on our affinity and topology. | |
1642 | * | |
1643 | * We prioritize the last cpu that the task executed on since | |
1644 | * it is most likely cache-hot in that location. | |
1645 | */ | |
96f874e2 | 1646 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1647 | return cpu; |
1648 | ||
1649 | /* | |
1650 | * Otherwise, we consult the sched_domains span maps to figure | |
1651 | * out which cpu is logically closest to our hot cache data. | |
1652 | */ | |
e2c88063 RR |
1653 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) |
1654 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
6e1254d2 | 1655 | |
cd4ae6ad | 1656 | rcu_read_lock(); |
e2c88063 RR |
1657 | for_each_domain(cpu, sd) { |
1658 | if (sd->flags & SD_WAKE_AFFINE) { | |
1659 | int best_cpu; | |
6e1254d2 | 1660 | |
e2c88063 RR |
1661 | /* |
1662 | * "this_cpu" is cheaper to preempt than a | |
1663 | * remote processor. | |
1664 | */ | |
1665 | if (this_cpu != -1 && | |
cd4ae6ad XF |
1666 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { |
1667 | rcu_read_unlock(); | |
e2c88063 | 1668 | return this_cpu; |
cd4ae6ad | 1669 | } |
e2c88063 RR |
1670 | |
1671 | best_cpu = cpumask_first_and(lowest_mask, | |
1672 | sched_domain_span(sd)); | |
cd4ae6ad XF |
1673 | if (best_cpu < nr_cpu_ids) { |
1674 | rcu_read_unlock(); | |
e2c88063 | 1675 | return best_cpu; |
cd4ae6ad | 1676 | } |
6e1254d2 GH |
1677 | } |
1678 | } | |
cd4ae6ad | 1679 | rcu_read_unlock(); |
6e1254d2 GH |
1680 | |
1681 | /* | |
1682 | * And finally, if there were no matches within the domains | |
1683 | * just give the caller *something* to work with from the compatible | |
1684 | * locations. | |
1685 | */ | |
e2c88063 RR |
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; | |
07b4032c GH |
1693 | } |
1694 | ||
1695 | /* Will lock the rq it finds */ | |
4df64c0b | 1696 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1697 | { |
1698 | struct rq *lowest_rq = NULL; | |
07b4032c | 1699 | int tries; |
4df64c0b | 1700 | int cpu; |
e8fa1362 | 1701 | |
07b4032c GH |
1702 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1703 | cpu = find_lowest_rq(task); | |
1704 | ||
2de0b463 | 1705 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1706 | break; |
1707 | ||
07b4032c GH |
1708 | lowest_rq = cpu_rq(cpu); |
1709 | ||
80e3d87b TC |
1710 | if (lowest_rq->rt.highest_prio.curr <= task->prio) { |
1711 | /* | |
1712 | * Target rq has tasks of equal or higher priority, | |
1713 | * retrying does not release any lock and is unlikely | |
1714 | * to yield a different result. | |
1715 | */ | |
1716 | lowest_rq = NULL; | |
1717 | break; | |
1718 | } | |
1719 | ||
e8fa1362 | 1720 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1721 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1722 | /* |
1723 | * We had to unlock the run queue. In | |
1724 | * the mean time, task could have | |
1725 | * migrated already or had its affinity changed. | |
1726 | * Also make sure that it wasn't scheduled on its rq. | |
1727 | */ | |
07b4032c | 1728 | if (unlikely(task_rq(task) != rq || |
0c98d344 | 1729 | !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_allowed) || |
07b4032c | 1730 | task_running(rq, task) || |
13b5ab02 | 1731 | !rt_task(task) || |
da0c1e65 | 1732 | !task_on_rq_queued(task))) { |
4df64c0b | 1733 | |
7f1b4393 | 1734 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1735 | lowest_rq = NULL; |
1736 | break; | |
1737 | } | |
1738 | } | |
1739 | ||
1740 | /* If this rq is still suitable use it. */ | |
e864c499 | 1741 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1742 | break; |
1743 | ||
1744 | /* try again */ | |
1b12bbc7 | 1745 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1746 | lowest_rq = NULL; |
1747 | } | |
1748 | ||
1749 | return lowest_rq; | |
1750 | } | |
1751 | ||
917b627d GH |
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)); | |
4b53a341 | 1764 | BUG_ON(p->nr_cpus_allowed <= 1); |
917b627d | 1765 | |
da0c1e65 | 1766 | BUG_ON(!task_on_rq_queued(p)); |
917b627d GH |
1767 | BUG_ON(!rt_task(p)); |
1768 | ||
1769 | return p; | |
1770 | } | |
1771 | ||
e8fa1362 SR |
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 | */ | |
697f0a48 | 1777 | static int push_rt_task(struct rq *rq) |
e8fa1362 SR |
1778 | { |
1779 | struct task_struct *next_task; | |
1780 | struct rq *lowest_rq; | |
311e800e | 1781 | int ret = 0; |
e8fa1362 | 1782 | |
a22d7fc1 GH |
1783 | if (!rq->rt.overloaded) |
1784 | return 0; | |
1785 | ||
917b627d | 1786 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
1787 | if (!next_task) |
1788 | return 0; | |
1789 | ||
49246274 | 1790 | retry: |
697f0a48 | 1791 | if (unlikely(next_task == rq->curr)) { |
f65eda4f | 1792 | WARN_ON(1); |
e8fa1362 | 1793 | return 0; |
f65eda4f | 1794 | } |
e8fa1362 SR |
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 | */ | |
697f0a48 | 1801 | if (unlikely(next_task->prio < rq->curr->prio)) { |
8875125e | 1802 | resched_curr(rq); |
e8fa1362 SR |
1803 | return 0; |
1804 | } | |
1805 | ||
697f0a48 | 1806 | /* We might release rq lock */ |
e8fa1362 SR |
1807 | get_task_struct(next_task); |
1808 | ||
1809 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 1810 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
1811 | if (!lowest_rq) { |
1812 | struct task_struct *task; | |
1813 | /* | |
311e800e | 1814 | * find_lock_lowest_rq releases rq->lock |
1563513d GH |
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. | |
e8fa1362 | 1820 | */ |
917b627d | 1821 | task = pick_next_pushable_task(rq); |
1563513d GH |
1822 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
1823 | /* | |
311e800e HD |
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. | |
1563513d | 1828 | */ |
1563513d | 1829 | goto out; |
e8fa1362 | 1830 | } |
917b627d | 1831 | |
1563513d GH |
1832 | if (!task) |
1833 | /* No more tasks, just exit */ | |
1834 | goto out; | |
1835 | ||
917b627d | 1836 | /* |
1563513d | 1837 | * Something has shifted, try again. |
917b627d | 1838 | */ |
1563513d GH |
1839 | put_task_struct(next_task); |
1840 | next_task = task; | |
1841 | goto retry; | |
e8fa1362 SR |
1842 | } |
1843 | ||
697f0a48 | 1844 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
1845 | set_task_cpu(next_task, lowest_rq->cpu); |
1846 | activate_task(lowest_rq, next_task, 0); | |
311e800e | 1847 | ret = 1; |
e8fa1362 | 1848 | |
8875125e | 1849 | resched_curr(lowest_rq); |
e8fa1362 | 1850 | |
1b12bbc7 | 1851 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 | 1852 | |
e8fa1362 SR |
1853 | out: |
1854 | put_task_struct(next_task); | |
1855 | ||
311e800e | 1856 | return ret; |
e8fa1362 SR |
1857 | } |
1858 | ||
e8fa1362 SR |
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 | ||
b6366f04 SR |
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 | ||
3e777f99 SRV |
1930 | /* |
1931 | * When a high priority task schedules out from a CPU and a lower priority | |
1932 | * task is scheduled in, a check is made to see if there's any RT tasks | |
1933 | * on other CPUs that are waiting to run because a higher priority RT task | |
1934 | * is currently running on its CPU. In this case, the CPU with multiple RT | |
1935 | * tasks queued on it (overloaded) needs to be notified that a CPU has opened | |
1936 | * up that may be able to run one of its non-running queued RT tasks. | |
1937 | * | |
1938 | * On large CPU boxes, there's the case that several CPUs could schedule | |
1939 | * a lower priority task at the same time, in which case it will look for | |
1940 | * any overloaded CPUs that it could pull a task from. To do this, the runqueue | |
1941 | * lock must be taken from that overloaded CPU. Having 10s of CPUs all fighting | |
1942 | * for a single overloaded CPU's runqueue lock can produce a large latency. | |
1943 | * (This has actually been observed on large boxes running cyclictest). | |
1944 | * Instead of taking the runqueue lock of the overloaded CPU, each of the | |
1945 | * CPUs that scheduled a lower priority task simply sends an IPI to the | |
1946 | * overloaded CPU. An IPI is much cheaper than taking an runqueue lock with | |
1947 | * lots of contention. The overloaded CPU will look to push its non-running | |
1948 | * RT task off, and if it does, it can then ignore the other IPIs coming | |
1949 | * in, and just pass those IPIs off to any other overloaded CPU. | |
1950 | * | |
1951 | * When a CPU schedules a lower priority task, it only sends an IPI to | |
1952 | * the "next" CPU that has overloaded RT tasks. This prevents IPI storms, | |
1953 | * as having 10 CPUs scheduling lower priority tasks and 10 CPUs with | |
1954 | * RT overloaded tasks, would cause 100 IPIs to go out at once. | |
1955 | * | |
1956 | * The overloaded RT CPU, when receiving an IPI, will try to push off its | |
1957 | * overloaded RT tasks and then send an IPI to the next CPU that has | |
1958 | * overloaded RT tasks. This stops when all CPUs with overloaded RT tasks | |
1959 | * have completed. Just because a CPU may have pushed off its own overloaded | |
1960 | * RT task does not mean it should stop sending the IPI around to other | |
1961 | * overloaded CPUs. There may be another RT task waiting to run on one of | |
1962 | * those CPUs that are of higher priority than the one that was just | |
1963 | * pushed. | |
1964 | * | |
1965 | * An optimization that could possibly be made is to make a CPU array similar | |
1966 | * to the cpupri array mask of all running RT tasks, but for the overloaded | |
1967 | * case, then the IPI could be sent to only the CPU with the highest priority | |
1968 | * RT task waiting, and that CPU could send off further IPIs to the CPU with | |
1969 | * the next highest waiting task. Since the overloaded case is much less likely | |
1970 | * to happen, the complexity of this implementation may not be worth it. | |
1971 | * Instead, just send an IPI around to all overloaded CPUs. | |
1972 | * | |
1973 | * The rq->rt.push_flags holds the status of the IPI that is going around. | |
1974 | * A run queue can only send out a single IPI at a time. The possible flags | |
1975 | * for rq->rt.push_flags are: | |
1976 | * | |
1977 | * (None or zero): No IPI is going around for the current rq | |
1978 | * RT_PUSH_IPI_EXECUTING: An IPI for the rq is being passed around | |
1979 | * RT_PUSH_IPI_RESTART: The priority of the running task for the rq | |
1980 | * has changed, and the IPI should restart | |
1981 | * circulating the overloaded CPUs again. | |
1982 | * | |
1983 | * rq->rt.push_cpu contains the CPU that is being sent the IPI. It is updated | |
1984 | * before sending to the next CPU. | |
1985 | * | |
1986 | * Instead of having all CPUs that schedule a lower priority task send | |
1987 | * an IPI to the same "first" CPU in the RT overload mask, they send it | |
1988 | * to the next overloaded CPU after their own CPU. This helps distribute | |
1989 | * the work when there's more than one overloaded CPU and multiple CPUs | |
1990 | * scheduling in lower priority tasks. | |
1991 | * | |
1992 | * When a rq schedules a lower priority task than what was currently | |
1993 | * running, the next CPU with overloaded RT tasks is examined first. | |
1994 | * That is, if CPU 1 and 5 are overloaded, and CPU 3 schedules a lower | |
1995 | * priority task, it will send an IPI first to CPU 5, then CPU 5 will | |
1996 | * send to CPU 1 if it is still overloaded. CPU 1 will clear the | |
1997 | * rq->rt.push_flags if RT_PUSH_IPI_RESTART is not set. | |
1998 | * | |
1999 | * The first CPU to notice IPI_RESTART is set, will clear that flag and then | |
2000 | * send an IPI to the next overloaded CPU after the rq->cpu and not the next | |
2001 | * CPU after push_cpu. That is, if CPU 1, 4 and 5 are overloaded when CPU 3 | |
2002 | * schedules a lower priority task, and the IPI_RESTART gets set while the | |
2003 | * handling is being done on CPU 5, it will clear the flag and send it back to | |
2004 | * CPU 4 instead of CPU 1. | |
2005 | * | |
2006 | * Note, the above logic can be disabled by turning off the sched_feature | |
2007 | * RT_PUSH_IPI. Then the rq lock of the overloaded CPU will simply be | |
2008 | * taken by the CPU requesting a pull and the waiting RT task will be pulled | |
2009 | * by that CPU. This may be fine for machines with few CPUs. | |
2010 | */ | |
b6366f04 SR |
2011 | static void tell_cpu_to_push(struct rq *rq) |
2012 | { | |
2013 | int cpu; | |
2014 | ||
2015 | if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) { | |
2016 | raw_spin_lock(&rq->rt.push_lock); | |
2017 | /* Make sure it's still executing */ | |
2018 | if (rq->rt.push_flags & RT_PUSH_IPI_EXECUTING) { | |
2019 | /* | |
2020 | * Tell the IPI to restart the loop as things have | |
2021 | * changed since it started. | |
2022 | */ | |
2023 | rq->rt.push_flags |= RT_PUSH_IPI_RESTART; | |
2024 | raw_spin_unlock(&rq->rt.push_lock); | |
2025 | return; | |
2026 | } | |
2027 | raw_spin_unlock(&rq->rt.push_lock); | |
2028 | } | |
2029 | ||
2030 | /* When here, there's no IPI going around */ | |
2031 | ||
2032 | rq->rt.push_cpu = rq->cpu; | |
2033 | cpu = find_next_push_cpu(rq); | |
2034 | if (cpu >= nr_cpu_ids) | |
2035 | return; | |
2036 | ||
2037 | rq->rt.push_flags = RT_PUSH_IPI_EXECUTING; | |
2038 | ||
2039 | irq_work_queue_on(&rq->rt.push_work, cpu); | |
2040 | } | |
2041 | ||
2042 | /* Called from hardirq context */ | |
2043 | static void try_to_push_tasks(void *arg) | |
2044 | { | |
2045 | struct rt_rq *rt_rq = arg; | |
2046 | struct rq *rq, *src_rq; | |
2047 | int this_cpu; | |
2048 | int cpu; | |
2049 | ||
2050 | this_cpu = rt_rq->push_cpu; | |
2051 | ||
2052 | /* Paranoid check */ | |
2053 | BUG_ON(this_cpu != smp_processor_id()); | |
2054 | ||
2055 | rq = cpu_rq(this_cpu); | |
2056 | src_rq = rq_of_rt_rq(rt_rq); | |
2057 | ||
2058 | again: | |
2059 | if (has_pushable_tasks(rq)) { | |
2060 | raw_spin_lock(&rq->lock); | |
2061 | push_rt_task(rq); | |
2062 | raw_spin_unlock(&rq->lock); | |
2063 | } | |
2064 | ||
2065 | /* Pass the IPI to the next rt overloaded queue */ | |
2066 | raw_spin_lock(&rt_rq->push_lock); | |
2067 | /* | |
2068 | * If the source queue changed since the IPI went out, | |
2069 | * we need to restart the search from that CPU again. | |
2070 | */ | |
2071 | if (rt_rq->push_flags & RT_PUSH_IPI_RESTART) { | |
2072 | rt_rq->push_flags &= ~RT_PUSH_IPI_RESTART; | |
2073 | rt_rq->push_cpu = src_rq->cpu; | |
2074 | } | |
2075 | ||
2076 | cpu = find_next_push_cpu(src_rq); | |
2077 | ||
2078 | if (cpu >= nr_cpu_ids) | |
2079 | rt_rq->push_flags &= ~RT_PUSH_IPI_EXECUTING; | |
2080 | raw_spin_unlock(&rt_rq->push_lock); | |
2081 | ||
2082 | if (cpu >= nr_cpu_ids) | |
2083 | return; | |
2084 | ||
2085 | /* | |
2086 | * It is possible that a restart caused this CPU to be | |
2087 | * chosen again. Don't bother with an IPI, just see if we | |
2088 | * have more to push. | |
2089 | */ | |
2090 | if (unlikely(cpu == rq->cpu)) | |
2091 | goto again; | |
2092 | ||
2093 | /* Try the next RT overloaded CPU */ | |
2094 | irq_work_queue_on(&rt_rq->push_work, cpu); | |
2095 | } | |
2096 | ||
2097 | static void push_irq_work_func(struct irq_work *work) | |
2098 | { | |
2099 | struct rt_rq *rt_rq = container_of(work, struct rt_rq, push_work); | |
2100 | ||
2101 | try_to_push_tasks(rt_rq); | |
2102 | } | |
2103 | #endif /* HAVE_RT_PUSH_IPI */ | |
2104 | ||
8046d680 | 2105 | static void pull_rt_task(struct rq *this_rq) |
f65eda4f | 2106 | { |
8046d680 PZ |
2107 | int this_cpu = this_rq->cpu, cpu; |
2108 | bool resched = false; | |
a8728944 | 2109 | struct task_struct *p; |
f65eda4f | 2110 | struct rq *src_rq; |
f65eda4f | 2111 | |
637f5085 | 2112 | if (likely(!rt_overloaded(this_rq))) |
8046d680 | 2113 | return; |
f65eda4f | 2114 | |
7c3f2ab7 PZ |
2115 | /* |
2116 | * Match the barrier from rt_set_overloaded; this guarantees that if we | |
2117 | * see overloaded we must also see the rto_mask bit. | |
2118 | */ | |
2119 | smp_rmb(); | |
2120 | ||
b6366f04 SR |
2121 | #ifdef HAVE_RT_PUSH_IPI |
2122 | if (sched_feat(RT_PUSH_IPI)) { | |
2123 | tell_cpu_to_push(this_rq); | |
8046d680 | 2124 | return; |
b6366f04 SR |
2125 | } |
2126 | #endif | |
2127 | ||
c6c4927b | 2128 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
2129 | if (this_cpu == cpu) |
2130 | continue; | |
2131 | ||
2132 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
2133 | |
2134 | /* | |
2135 | * Don't bother taking the src_rq->lock if the next highest | |
2136 | * task is known to be lower-priority than our current task. | |
2137 | * This may look racy, but if this value is about to go | |
2138 | * logically higher, the src_rq will push this task away. | |
2139 | * And if its going logically lower, we do not care | |
2140 | */ | |
2141 | if (src_rq->rt.highest_prio.next >= | |
2142 | this_rq->rt.highest_prio.curr) | |
2143 | continue; | |
2144 | ||
f65eda4f SR |
2145 | /* |
2146 | * We can potentially drop this_rq's lock in | |
2147 | * double_lock_balance, and another CPU could | |
a8728944 | 2148 | * alter this_rq |
f65eda4f | 2149 | */ |
a8728944 | 2150 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
2151 | |
2152 | /* | |
e23ee747 KT |
2153 | * We can pull only a task, which is pushable |
2154 | * on its rq, and no others. | |
f65eda4f | 2155 | */ |
e23ee747 | 2156 | p = pick_highest_pushable_task(src_rq, this_cpu); |
f65eda4f SR |
2157 | |
2158 | /* | |
2159 | * Do we have an RT task that preempts | |
2160 | * the to-be-scheduled task? | |
2161 | */ | |
a8728944 | 2162 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f | 2163 | WARN_ON(p == src_rq->curr); |
da0c1e65 | 2164 | WARN_ON(!task_on_rq_queued(p)); |
f65eda4f SR |
2165 | |
2166 | /* | |
2167 | * There's a chance that p is higher in priority | |
2168 | * than what's currently running on its cpu. | |
2169 | * This is just that p is wakeing up and hasn't | |
2170 | * had a chance to schedule. We only pull | |
2171 | * p if it is lower in priority than the | |
a8728944 | 2172 | * current task on the run queue |
f65eda4f | 2173 | */ |
a8728944 | 2174 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 2175 | goto skip; |
f65eda4f | 2176 | |
8046d680 | 2177 | resched = true; |
f65eda4f SR |
2178 | |
2179 | deactivate_task(src_rq, p, 0); | |
2180 | set_task_cpu(p, this_cpu); | |
2181 | activate_task(this_rq, p, 0); | |
2182 | /* | |
2183 | * We continue with the search, just in | |
2184 | * case there's an even higher prio task | |
25985edc | 2185 | * in another runqueue. (low likelihood |
f65eda4f | 2186 | * but possible) |
f65eda4f | 2187 | */ |
f65eda4f | 2188 | } |
49246274 | 2189 | skip: |
1b12bbc7 | 2190 | double_unlock_balance(this_rq, src_rq); |
f65eda4f SR |
2191 | } |
2192 | ||
8046d680 PZ |
2193 | if (resched) |
2194 | resched_curr(this_rq); | |
f65eda4f SR |
2195 | } |
2196 | ||
8ae121ac GH |
2197 | /* |
2198 | * If we are not running and we are not going to reschedule soon, we should | |
2199 | * try to push tasks away now | |
2200 | */ | |
efbbd05a | 2201 | static void task_woken_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 2202 | { |
9a897c5a | 2203 | if (!task_running(rq, p) && |
8ae121ac | 2204 | !test_tsk_need_resched(rq->curr) && |
4b53a341 | 2205 | p->nr_cpus_allowed > 1 && |
1baca4ce | 2206 | (dl_task(rq->curr) || rt_task(rq->curr)) && |
4b53a341 | 2207 | (rq->curr->nr_cpus_allowed < 2 || |
3be209a8 | 2208 | rq->curr->prio <= p->prio)) |
4642dafd SR |
2209 | push_rt_tasks(rq); |
2210 | } | |
2211 | ||
bdd7c81b | 2212 | /* Assumes rq->lock is held */ |
1f11eb6a | 2213 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
2214 | { |
2215 | if (rq->rt.overloaded) | |
2216 | rt_set_overload(rq); | |
6e0534f2 | 2217 | |
7def2be1 PZ |
2218 | __enable_runtime(rq); |
2219 | ||
e864c499 | 2220 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
2221 | } |
2222 | ||
2223 | /* Assumes rq->lock is held */ | |
1f11eb6a | 2224 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
2225 | { |
2226 | if (rq->rt.overloaded) | |
2227 | rt_clear_overload(rq); | |
6e0534f2 | 2228 | |
7def2be1 PZ |
2229 | __disable_runtime(rq); |
2230 | ||
6e0534f2 | 2231 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 2232 | } |
cb469845 SR |
2233 | |
2234 | /* | |
2235 | * When switch from the rt queue, we bring ourselves to a position | |
2236 | * that we might want to pull RT tasks from other runqueues. | |
2237 | */ | |
da7a735e | 2238 | static void switched_from_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
2239 | { |
2240 | /* | |
2241 | * If there are other RT tasks then we will reschedule | |
2242 | * and the scheduling of the other RT tasks will handle | |
2243 | * the balancing. But if we are the last RT task | |
2244 | * we may need to handle the pulling of RT tasks | |
2245 | * now. | |
2246 | */ | |
da0c1e65 | 2247 | if (!task_on_rq_queued(p) || rq->rt.rt_nr_running) |
1158ddb5 KT |
2248 | return; |
2249 | ||
fd7a4bed | 2250 | queue_pull_task(rq); |
cb469845 | 2251 | } |
3d8cbdf8 | 2252 | |
11c785b7 | 2253 | void __init init_sched_rt_class(void) |
3d8cbdf8 RR |
2254 | { |
2255 | unsigned int i; | |
2256 | ||
029632fb | 2257 | for_each_possible_cpu(i) { |
eaa95840 | 2258 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
6ca09dfc | 2259 | GFP_KERNEL, cpu_to_node(i)); |
029632fb | 2260 | } |
3d8cbdf8 | 2261 | } |
cb469845 SR |
2262 | #endif /* CONFIG_SMP */ |
2263 | ||
2264 | /* | |
2265 | * When switching a task to RT, we may overload the runqueue | |
2266 | * with RT tasks. In this case we try to push them off to | |
2267 | * other runqueues. | |
2268 | */ | |
da7a735e | 2269 | static void switched_to_rt(struct rq *rq, struct task_struct *p) |
cb469845 | 2270 | { |
cb469845 SR |
2271 | /* |
2272 | * If we are already running, then there's nothing | |
2273 | * that needs to be done. But if we are not running | |
2274 | * we may need to preempt the current running task. | |
2275 | * If that current running task is also an RT task | |
2276 | * then see if we can move to another run queue. | |
2277 | */ | |
da0c1e65 | 2278 | if (task_on_rq_queued(p) && rq->curr != p) { |
cb469845 | 2279 | #ifdef CONFIG_SMP |
4b53a341 | 2280 | if (p->nr_cpus_allowed > 1 && rq->rt.overloaded) |
fd7a4bed | 2281 | queue_push_tasks(rq); |
619bd4a7 | 2282 | #endif /* CONFIG_SMP */ |
fd7a4bed | 2283 | if (p->prio < rq->curr->prio) |
8875125e | 2284 | resched_curr(rq); |
cb469845 SR |
2285 | } |
2286 | } | |
2287 | ||
2288 | /* | |
2289 | * Priority of the task has changed. This may cause | |
2290 | * us to initiate a push or pull. | |
2291 | */ | |
da7a735e PZ |
2292 | static void |
2293 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 2294 | { |
da0c1e65 | 2295 | if (!task_on_rq_queued(p)) |
da7a735e PZ |
2296 | return; |
2297 | ||
2298 | if (rq->curr == p) { | |
cb469845 SR |
2299 | #ifdef CONFIG_SMP |
2300 | /* | |
2301 | * If our priority decreases while running, we | |
2302 | * may need to pull tasks to this runqueue. | |
2303 | */ | |
2304 | if (oldprio < p->prio) | |
fd7a4bed PZ |
2305 | queue_pull_task(rq); |
2306 | ||
cb469845 SR |
2307 | /* |
2308 | * If there's a higher priority task waiting to run | |
fd7a4bed | 2309 | * then reschedule. |
cb469845 | 2310 | */ |
fd7a4bed | 2311 | if (p->prio > rq->rt.highest_prio.curr) |
8875125e | 2312 | resched_curr(rq); |
cb469845 SR |
2313 | #else |
2314 | /* For UP simply resched on drop of prio */ | |
2315 | if (oldprio < p->prio) | |
8875125e | 2316 | resched_curr(rq); |
e8fa1362 | 2317 | #endif /* CONFIG_SMP */ |
cb469845 SR |
2318 | } else { |
2319 | /* | |
2320 | * This task is not running, but if it is | |
2321 | * greater than the current running task | |
2322 | * then reschedule. | |
2323 | */ | |
2324 | if (p->prio < rq->curr->prio) | |
8875125e | 2325 | resched_curr(rq); |
cb469845 SR |
2326 | } |
2327 | } | |
2328 | ||
b18b6a9c | 2329 | #ifdef CONFIG_POSIX_TIMERS |
78f2c7db PZ |
2330 | static void watchdog(struct rq *rq, struct task_struct *p) |
2331 | { | |
2332 | unsigned long soft, hard; | |
2333 | ||
78d7d407 JS |
2334 | /* max may change after cur was read, this will be fixed next tick */ |
2335 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
2336 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
78f2c7db PZ |
2337 | |
2338 | if (soft != RLIM_INFINITY) { | |
2339 | unsigned long next; | |
2340 | ||
57d2aa00 YX |
2341 | if (p->rt.watchdog_stamp != jiffies) { |
2342 | p->rt.timeout++; | |
2343 | p->rt.watchdog_stamp = jiffies; | |
2344 | } | |
2345 | ||
78f2c7db | 2346 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); |
5a52dd50 | 2347 | if (p->rt.timeout > next) |
f06febc9 | 2348 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
78f2c7db PZ |
2349 | } |
2350 | } | |
b18b6a9c NP |
2351 | #else |
2352 | static inline void watchdog(struct rq *rq, struct task_struct *p) { } | |
2353 | #endif | |
bb44e5d1 | 2354 | |
8f4d37ec | 2355 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 2356 | { |
454c7999 CC |
2357 | struct sched_rt_entity *rt_se = &p->rt; |
2358 | ||
67e2be02 PZ |
2359 | update_curr_rt(rq); |
2360 | ||
78f2c7db PZ |
2361 | watchdog(rq, p); |
2362 | ||
bb44e5d1 IM |
2363 | /* |
2364 | * RR tasks need a special form of timeslice management. | |
2365 | * FIFO tasks have no timeslices. | |
2366 | */ | |
2367 | if (p->policy != SCHED_RR) | |
2368 | return; | |
2369 | ||
fa717060 | 2370 | if (--p->rt.time_slice) |
bb44e5d1 IM |
2371 | return; |
2372 | ||
ce0dbbbb | 2373 | p->rt.time_slice = sched_rr_timeslice; |
bb44e5d1 | 2374 | |
98fbc798 | 2375 | /* |
e9aa39bb LB |
2376 | * Requeue to the end of queue if we (and all of our ancestors) are not |
2377 | * the only element on the queue | |
98fbc798 | 2378 | */ |
454c7999 CC |
2379 | for_each_sched_rt_entity(rt_se) { |
2380 | if (rt_se->run_list.prev != rt_se->run_list.next) { | |
2381 | requeue_task_rt(rq, p, 0); | |
8aa6f0eb | 2382 | resched_curr(rq); |
454c7999 CC |
2383 | return; |
2384 | } | |
98fbc798 | 2385 | } |
bb44e5d1 IM |
2386 | } |
2387 | ||
83b699ed SV |
2388 | static void set_curr_task_rt(struct rq *rq) |
2389 | { | |
2390 | struct task_struct *p = rq->curr; | |
2391 | ||
78becc27 | 2392 | p->se.exec_start = rq_clock_task(rq); |
917b627d GH |
2393 | |
2394 | /* The running task is never eligible for pushing */ | |
2395 | dequeue_pushable_task(rq, p); | |
83b699ed SV |
2396 | } |
2397 | ||
6d686f45 | 2398 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) |
0d721cea PW |
2399 | { |
2400 | /* | |
2401 | * Time slice is 0 for SCHED_FIFO tasks | |
2402 | */ | |
2403 | if (task->policy == SCHED_RR) | |
ce0dbbbb | 2404 | return sched_rr_timeslice; |
0d721cea PW |
2405 | else |
2406 | return 0; | |
2407 | } | |
2408 | ||
029632fb | 2409 | const struct sched_class rt_sched_class = { |
5522d5d5 | 2410 | .next = &fair_sched_class, |
bb44e5d1 IM |
2411 | .enqueue_task = enqueue_task_rt, |
2412 | .dequeue_task = dequeue_task_rt, | |
2413 | .yield_task = yield_task_rt, | |
2414 | ||
2415 | .check_preempt_curr = check_preempt_curr_rt, | |
2416 | ||
2417 | .pick_next_task = pick_next_task_rt, | |
2418 | .put_prev_task = put_prev_task_rt, | |
2419 | ||
681f3e68 | 2420 | #ifdef CONFIG_SMP |
4ce72a2c LZ |
2421 | .select_task_rq = select_task_rq_rt, |
2422 | ||
6c37067e | 2423 | .set_cpus_allowed = set_cpus_allowed_common, |
1f11eb6a GH |
2424 | .rq_online = rq_online_rt, |
2425 | .rq_offline = rq_offline_rt, | |
efbbd05a | 2426 | .task_woken = task_woken_rt, |
cb469845 | 2427 | .switched_from = switched_from_rt, |
681f3e68 | 2428 | #endif |
bb44e5d1 | 2429 | |
83b699ed | 2430 | .set_curr_task = set_curr_task_rt, |
bb44e5d1 | 2431 | .task_tick = task_tick_rt, |
cb469845 | 2432 | |
0d721cea PW |
2433 | .get_rr_interval = get_rr_interval_rt, |
2434 | ||
cb469845 SR |
2435 | .prio_changed = prio_changed_rt, |
2436 | .switched_to = switched_to_rt, | |
6e998916 SG |
2437 | |
2438 | .update_curr = update_curr_rt, | |
bb44e5d1 | 2439 | }; |
ada18de2 PZ |
2440 | |
2441 | #ifdef CONFIG_SCHED_DEBUG | |
2442 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
2443 | ||
029632fb | 2444 | void print_rt_stats(struct seq_file *m, int cpu) |
ada18de2 | 2445 | { |
ec514c48 | 2446 | rt_rq_iter_t iter; |
ada18de2 PZ |
2447 | struct rt_rq *rt_rq; |
2448 | ||
2449 | rcu_read_lock(); | |
ec514c48 | 2450 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) |
ada18de2 PZ |
2451 | print_rt_rq(m, cpu, rt_rq); |
2452 | rcu_read_unlock(); | |
2453 | } | |
55e12e5e | 2454 | #endif /* CONFIG_SCHED_DEBUG */ |