Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
bb44e5d1 IM |
2 | /* |
3 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR | |
4 | * policies) | |
5 | */ | |
371bf427 | 6 | |
ce0dbbbb | 7 | int sched_rr_timeslice = RR_TIMESLICE; |
d505b8af HC |
8 | /* More than 4 hours if BW_SHIFT equals 20. */ |
9 | static const u64 max_rt_runtime = MAX_BW; | |
ce0dbbbb | 10 | |
029632fb PZ |
11 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); |
12 | ||
13 | struct rt_bandwidth def_rt_bandwidth; | |
14 | ||
d9ab0e63 ZN |
15 | /* |
16 | * period over which we measure -rt task CPU usage in us. | |
17 | * default: 1s | |
18 | */ | |
19 | unsigned int sysctl_sched_rt_period = 1000000; | |
20 | ||
21 | /* | |
22 | * part of the period that we allow rt tasks to run in us. | |
23 | * default: 0.95s | |
24 | */ | |
25 | int sysctl_sched_rt_runtime = 950000; | |
26 | ||
28f152cd BZ |
27 | #ifdef CONFIG_SYSCTL |
28 | static int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE; | |
d9ab0e63 ZN |
29 | static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, |
30 | size_t *lenp, loff_t *ppos); | |
dafd7a9d ZN |
31 | static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, |
32 | size_t *lenp, loff_t *ppos); | |
d9ab0e63 ZN |
33 | static struct ctl_table sched_rt_sysctls[] = { |
34 | { | |
35 | .procname = "sched_rt_period_us", | |
36 | .data = &sysctl_sched_rt_period, | |
37 | .maxlen = sizeof(unsigned int), | |
38 | .mode = 0644, | |
39 | .proc_handler = sched_rt_handler, | |
40 | }, | |
41 | { | |
42 | .procname = "sched_rt_runtime_us", | |
43 | .data = &sysctl_sched_rt_runtime, | |
44 | .maxlen = sizeof(int), | |
45 | .mode = 0644, | |
46 | .proc_handler = sched_rt_handler, | |
47 | }, | |
dafd7a9d ZN |
48 | { |
49 | .procname = "sched_rr_timeslice_ms", | |
50 | .data = &sysctl_sched_rr_timeslice, | |
51 | .maxlen = sizeof(int), | |
52 | .mode = 0644, | |
53 | .proc_handler = sched_rr_handler, | |
54 | }, | |
d9ab0e63 ZN |
55 | {} |
56 | }; | |
57 | ||
58 | static int __init sched_rt_sysctl_init(void) | |
59 | { | |
60 | register_sysctl_init("kernel", sched_rt_sysctls); | |
61 | return 0; | |
62 | } | |
63 | late_initcall(sched_rt_sysctl_init); | |
64 | #endif | |
65 | ||
029632fb PZ |
66 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) |
67 | { | |
68 | struct rt_bandwidth *rt_b = | |
69 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
029632fb | 70 | int idle = 0; |
77a4d1a1 | 71 | int overrun; |
029632fb | 72 | |
77a4d1a1 | 73 | raw_spin_lock(&rt_b->rt_runtime_lock); |
029632fb | 74 | for (;;) { |
77a4d1a1 | 75 | overrun = hrtimer_forward_now(timer, rt_b->rt_period); |
029632fb PZ |
76 | if (!overrun) |
77 | break; | |
78 | ||
77a4d1a1 | 79 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
029632fb | 80 | idle = do_sched_rt_period_timer(rt_b, overrun); |
77a4d1a1 | 81 | raw_spin_lock(&rt_b->rt_runtime_lock); |
029632fb | 82 | } |
4cfafd30 PZ |
83 | if (idle) |
84 | rt_b->rt_period_active = 0; | |
77a4d1a1 | 85 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
029632fb PZ |
86 | |
87 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
88 | } | |
89 | ||
90 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
91 | { | |
92 | rt_b->rt_period = ns_to_ktime(period); | |
93 | rt_b->rt_runtime = runtime; | |
94 | ||
95 | raw_spin_lock_init(&rt_b->rt_runtime_lock); | |
96 | ||
d5096aa6 SAS |
97 | hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC, |
98 | HRTIMER_MODE_REL_HARD); | |
029632fb PZ |
99 | rt_b->rt_period_timer.function = sched_rt_period_timer; |
100 | } | |
101 | ||
9b58e976 | 102 | static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b) |
029632fb | 103 | { |
029632fb | 104 | raw_spin_lock(&rt_b->rt_runtime_lock); |
4cfafd30 PZ |
105 | if (!rt_b->rt_period_active) { |
106 | rt_b->rt_period_active = 1; | |
c3a990dc SR |
107 | /* |
108 | * SCHED_DEADLINE updates the bandwidth, as a run away | |
109 | * RT task with a DL task could hog a CPU. But DL does | |
110 | * not reset the period. If a deadline task was running | |
111 | * without an RT task running, it can cause RT tasks to | |
112 | * throttle when they start up. Kick the timer right away | |
113 | * to update the period. | |
114 | */ | |
115 | hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0)); | |
d5096aa6 SAS |
116 | hrtimer_start_expires(&rt_b->rt_period_timer, |
117 | HRTIMER_MODE_ABS_PINNED_HARD); | |
4cfafd30 | 118 | } |
029632fb PZ |
119 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
120 | } | |
121 | ||
9b58e976 LH |
122 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) |
123 | { | |
124 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) | |
125 | return; | |
126 | ||
127 | do_start_rt_bandwidth(rt_b); | |
128 | } | |
129 | ||
07c54f7a | 130 | void init_rt_rq(struct rt_rq *rt_rq) |
029632fb PZ |
131 | { |
132 | struct rt_prio_array *array; | |
133 | int i; | |
134 | ||
135 | array = &rt_rq->active; | |
136 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
137 | INIT_LIST_HEAD(array->queue + i); | |
138 | __clear_bit(i, array->bitmap); | |
139 | } | |
140 | /* delimiter for bitsearch: */ | |
141 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
142 | ||
143 | #if defined CONFIG_SMP | |
934fc331 PZ |
144 | rt_rq->highest_prio.curr = MAX_RT_PRIO-1; |
145 | rt_rq->highest_prio.next = MAX_RT_PRIO-1; | |
029632fb PZ |
146 | rt_rq->rt_nr_migratory = 0; |
147 | rt_rq->overloaded = 0; | |
148 | plist_head_init(&rt_rq->pushable_tasks); | |
b6366f04 | 149 | #endif /* CONFIG_SMP */ |
f4ebcbc0 KT |
150 | /* We start is dequeued state, because no RT tasks are queued */ |
151 | rt_rq->rt_queued = 0; | |
029632fb PZ |
152 | |
153 | rt_rq->rt_time = 0; | |
154 | rt_rq->rt_throttled = 0; | |
155 | rt_rq->rt_runtime = 0; | |
156 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); | |
157 | } | |
158 | ||
8f48894f | 159 | #ifdef CONFIG_RT_GROUP_SCHED |
029632fb PZ |
160 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) |
161 | { | |
162 | hrtimer_cancel(&rt_b->rt_period_timer); | |
163 | } | |
8f48894f PZ |
164 | |
165 | #define rt_entity_is_task(rt_se) (!(rt_se)->my_q) | |
166 | ||
398a153b GH |
167 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
168 | { | |
8f48894f PZ |
169 | #ifdef CONFIG_SCHED_DEBUG |
170 | WARN_ON_ONCE(!rt_entity_is_task(rt_se)); | |
171 | #endif | |
398a153b GH |
172 | return container_of(rt_se, struct task_struct, rt); |
173 | } | |
174 | ||
398a153b GH |
175 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
176 | { | |
177 | return rt_rq->rq; | |
178 | } | |
179 | ||
180 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
181 | { | |
182 | return rt_se->rt_rq; | |
183 | } | |
184 | ||
653d07a6 KT |
185 | static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) |
186 | { | |
187 | struct rt_rq *rt_rq = rt_se->rt_rq; | |
188 | ||
189 | return rt_rq->rq; | |
190 | } | |
191 | ||
b027789e | 192 | void unregister_rt_sched_group(struct task_group *tg) |
029632fb | 193 | { |
029632fb PZ |
194 | if (tg->rt_se) |
195 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
196 | ||
b027789e MK |
197 | } |
198 | ||
199 | void free_rt_sched_group(struct task_group *tg) | |
200 | { | |
201 | int i; | |
202 | ||
029632fb PZ |
203 | for_each_possible_cpu(i) { |
204 | if (tg->rt_rq) | |
205 | kfree(tg->rt_rq[i]); | |
206 | if (tg->rt_se) | |
207 | kfree(tg->rt_se[i]); | |
208 | } | |
209 | ||
210 | kfree(tg->rt_rq); | |
211 | kfree(tg->rt_se); | |
212 | } | |
213 | ||
214 | void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, | |
215 | struct sched_rt_entity *rt_se, int cpu, | |
216 | struct sched_rt_entity *parent) | |
217 | { | |
218 | struct rq *rq = cpu_rq(cpu); | |
219 | ||
934fc331 | 220 | rt_rq->highest_prio.curr = MAX_RT_PRIO-1; |
029632fb PZ |
221 | rt_rq->rt_nr_boosted = 0; |
222 | rt_rq->rq = rq; | |
223 | rt_rq->tg = tg; | |
224 | ||
225 | tg->rt_rq[cpu] = rt_rq; | |
226 | tg->rt_se[cpu] = rt_se; | |
227 | ||
228 | if (!rt_se) | |
229 | return; | |
230 | ||
231 | if (!parent) | |
232 | rt_se->rt_rq = &rq->rt; | |
233 | else | |
234 | rt_se->rt_rq = parent->my_q; | |
235 | ||
236 | rt_se->my_q = rt_rq; | |
237 | rt_se->parent = parent; | |
238 | INIT_LIST_HEAD(&rt_se->run_list); | |
239 | } | |
240 | ||
241 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
242 | { | |
243 | struct rt_rq *rt_rq; | |
244 | struct sched_rt_entity *rt_se; | |
245 | int i; | |
246 | ||
6396bb22 | 247 | tg->rt_rq = kcalloc(nr_cpu_ids, sizeof(rt_rq), GFP_KERNEL); |
029632fb PZ |
248 | if (!tg->rt_rq) |
249 | goto err; | |
6396bb22 | 250 | tg->rt_se = kcalloc(nr_cpu_ids, sizeof(rt_se), GFP_KERNEL); |
029632fb PZ |
251 | if (!tg->rt_se) |
252 | goto err; | |
253 | ||
254 | init_rt_bandwidth(&tg->rt_bandwidth, | |
255 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
256 | ||
257 | for_each_possible_cpu(i) { | |
258 | rt_rq = kzalloc_node(sizeof(struct rt_rq), | |
259 | GFP_KERNEL, cpu_to_node(i)); | |
260 | if (!rt_rq) | |
261 | goto err; | |
262 | ||
263 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), | |
264 | GFP_KERNEL, cpu_to_node(i)); | |
265 | if (!rt_se) | |
266 | goto err_free_rq; | |
267 | ||
07c54f7a | 268 | init_rt_rq(rt_rq); |
029632fb PZ |
269 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
270 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); | |
271 | } | |
272 | ||
273 | return 1; | |
274 | ||
275 | err_free_rq: | |
276 | kfree(rt_rq); | |
277 | err: | |
278 | return 0; | |
279 | } | |
280 | ||
398a153b GH |
281 | #else /* CONFIG_RT_GROUP_SCHED */ |
282 | ||
a1ba4d8b PZ |
283 | #define rt_entity_is_task(rt_se) (1) |
284 | ||
8f48894f PZ |
285 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
286 | { | |
287 | return container_of(rt_se, struct task_struct, rt); | |
288 | } | |
289 | ||
398a153b GH |
290 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
291 | { | |
292 | return container_of(rt_rq, struct rq, rt); | |
293 | } | |
294 | ||
653d07a6 | 295 | static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) |
398a153b GH |
296 | { |
297 | struct task_struct *p = rt_task_of(rt_se); | |
653d07a6 KT |
298 | |
299 | return task_rq(p); | |
300 | } | |
301 | ||
302 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
303 | { | |
304 | struct rq *rq = rq_of_rt_se(rt_se); | |
398a153b GH |
305 | |
306 | return &rq->rt; | |
307 | } | |
308 | ||
b027789e MK |
309 | void unregister_rt_sched_group(struct task_group *tg) { } |
310 | ||
029632fb PZ |
311 | void free_rt_sched_group(struct task_group *tg) { } |
312 | ||
313 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
314 | { | |
315 | return 1; | |
316 | } | |
398a153b GH |
317 | #endif /* CONFIG_RT_GROUP_SCHED */ |
318 | ||
4fd29176 | 319 | #ifdef CONFIG_SMP |
84de4274 | 320 | |
dc877341 PZ |
321 | static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) |
322 | { | |
323 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
120455c5 | 324 | return rq->online && rq->rt.highest_prio.curr > prev->prio; |
dc877341 PZ |
325 | } |
326 | ||
637f5085 | 327 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 328 | { |
637f5085 | 329 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 330 | } |
84de4274 | 331 | |
4fd29176 SR |
332 | static inline void rt_set_overload(struct rq *rq) |
333 | { | |
1f11eb6a GH |
334 | if (!rq->online) |
335 | return; | |
336 | ||
c6c4927b | 337 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
338 | /* |
339 | * Make sure the mask is visible before we set | |
340 | * the overload count. That is checked to determine | |
341 | * if we should look at the mask. It would be a shame | |
342 | * if we looked at the mask, but the mask was not | |
343 | * updated yet. | |
7c3f2ab7 PZ |
344 | * |
345 | * Matched by the barrier in pull_rt_task(). | |
4fd29176 | 346 | */ |
7c3f2ab7 | 347 | smp_wmb(); |
637f5085 | 348 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 349 | } |
84de4274 | 350 | |
4fd29176 SR |
351 | static inline void rt_clear_overload(struct rq *rq) |
352 | { | |
1f11eb6a GH |
353 | if (!rq->online) |
354 | return; | |
355 | ||
4fd29176 | 356 | /* the order here really doesn't matter */ |
637f5085 | 357 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 358 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 359 | } |
73fe6aae | 360 | |
398a153b | 361 | static void update_rt_migration(struct rt_rq *rt_rq) |
73fe6aae | 362 | { |
a1ba4d8b | 363 | if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) { |
398a153b GH |
364 | if (!rt_rq->overloaded) { |
365 | rt_set_overload(rq_of_rt_rq(rt_rq)); | |
366 | rt_rq->overloaded = 1; | |
cdc8eb98 | 367 | } |
398a153b GH |
368 | } else if (rt_rq->overloaded) { |
369 | rt_clear_overload(rq_of_rt_rq(rt_rq)); | |
370 | rt_rq->overloaded = 0; | |
637f5085 | 371 | } |
73fe6aae | 372 | } |
4fd29176 | 373 | |
398a153b GH |
374 | static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
375 | { | |
29baa747 PZ |
376 | struct task_struct *p; |
377 | ||
a1ba4d8b PZ |
378 | if (!rt_entity_is_task(rt_se)) |
379 | return; | |
380 | ||
29baa747 | 381 | p = rt_task_of(rt_se); |
a1ba4d8b PZ |
382 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; |
383 | ||
384 | rt_rq->rt_nr_total++; | |
4b53a341 | 385 | if (p->nr_cpus_allowed > 1) |
398a153b GH |
386 | rt_rq->rt_nr_migratory++; |
387 | ||
388 | update_rt_migration(rt_rq); | |
389 | } | |
390 | ||
391 | static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
392 | { | |
29baa747 PZ |
393 | struct task_struct *p; |
394 | ||
a1ba4d8b PZ |
395 | if (!rt_entity_is_task(rt_se)) |
396 | return; | |
397 | ||
29baa747 | 398 | p = rt_task_of(rt_se); |
a1ba4d8b PZ |
399 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; |
400 | ||
401 | rt_rq->rt_nr_total--; | |
4b53a341 | 402 | if (p->nr_cpus_allowed > 1) |
398a153b GH |
403 | rt_rq->rt_nr_migratory--; |
404 | ||
405 | update_rt_migration(rt_rq); | |
406 | } | |
407 | ||
5181f4a4 SR |
408 | static inline int has_pushable_tasks(struct rq *rq) |
409 | { | |
410 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
411 | } | |
412 | ||
8e5bad7d KC |
413 | static DEFINE_PER_CPU(struct balance_callback, rt_push_head); |
414 | static DEFINE_PER_CPU(struct balance_callback, rt_pull_head); | |
e3fca9e7 PZ |
415 | |
416 | static void push_rt_tasks(struct rq *); | |
fd7a4bed | 417 | static void pull_rt_task(struct rq *); |
e3fca9e7 | 418 | |
02d8ec94 | 419 | static inline void rt_queue_push_tasks(struct rq *rq) |
dc877341 | 420 | { |
e3fca9e7 PZ |
421 | if (!has_pushable_tasks(rq)) |
422 | return; | |
423 | ||
fd7a4bed PZ |
424 | queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks); |
425 | } | |
426 | ||
02d8ec94 | 427 | static inline void rt_queue_pull_task(struct rq *rq) |
fd7a4bed PZ |
428 | { |
429 | queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task); | |
dc877341 PZ |
430 | } |
431 | ||
917b627d GH |
432 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
433 | { | |
434 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
435 | plist_node_init(&p->pushable_tasks, p->prio); | |
436 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
5181f4a4 SR |
437 | |
438 | /* Update the highest prio pushable task */ | |
439 | if (p->prio < rq->rt.highest_prio.next) | |
440 | rq->rt.highest_prio.next = p->prio; | |
917b627d GH |
441 | } |
442 | ||
443 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
444 | { | |
445 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
917b627d | 446 | |
5181f4a4 SR |
447 | /* Update the new highest prio pushable task */ |
448 | if (has_pushable_tasks(rq)) { | |
449 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
450 | struct task_struct, pushable_tasks); | |
451 | rq->rt.highest_prio.next = p->prio; | |
934fc331 PZ |
452 | } else { |
453 | rq->rt.highest_prio.next = MAX_RT_PRIO-1; | |
454 | } | |
bcf08df3 IM |
455 | } |
456 | ||
917b627d GH |
457 | #else |
458 | ||
ceacc2c1 | 459 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
fa85ae24 | 460 | { |
6f505b16 PZ |
461 | } |
462 | ||
ceacc2c1 PZ |
463 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
464 | { | |
465 | } | |
466 | ||
b07430ac | 467 | static inline |
ceacc2c1 PZ |
468 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
469 | { | |
470 | } | |
471 | ||
398a153b | 472 | static inline |
ceacc2c1 PZ |
473 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
474 | { | |
475 | } | |
917b627d | 476 | |
02d8ec94 | 477 | static inline void rt_queue_push_tasks(struct rq *rq) |
dc877341 PZ |
478 | { |
479 | } | |
4fd29176 SR |
480 | #endif /* CONFIG_SMP */ |
481 | ||
f4ebcbc0 | 482 | static void enqueue_top_rt_rq(struct rt_rq *rt_rq); |
5c66d1b9 | 483 | static void dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count); |
f4ebcbc0 | 484 | |
6f505b16 PZ |
485 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
486 | { | |
ff77e468 | 487 | return rt_se->on_rq; |
6f505b16 PZ |
488 | } |
489 | ||
804d402f QY |
490 | #ifdef CONFIG_UCLAMP_TASK |
491 | /* | |
492 | * Verify the fitness of task @p to run on @cpu taking into account the uclamp | |
493 | * settings. | |
494 | * | |
495 | * This check is only important for heterogeneous systems where uclamp_min value | |
496 | * is higher than the capacity of a @cpu. For non-heterogeneous system this | |
497 | * function will always return true. | |
498 | * | |
499 | * The function will return true if the capacity of the @cpu is >= the | |
500 | * uclamp_min and false otherwise. | |
501 | * | |
502 | * Note that uclamp_min will be clamped to uclamp_max if uclamp_min | |
503 | * > uclamp_max. | |
504 | */ | |
505 | static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) | |
506 | { | |
507 | unsigned int min_cap; | |
508 | unsigned int max_cap; | |
509 | unsigned int cpu_cap; | |
510 | ||
511 | /* Only heterogeneous systems can benefit from this check */ | |
740cf8a7 | 512 | if (!sched_asym_cpucap_active()) |
804d402f QY |
513 | return true; |
514 | ||
515 | min_cap = uclamp_eff_value(p, UCLAMP_MIN); | |
516 | max_cap = uclamp_eff_value(p, UCLAMP_MAX); | |
517 | ||
518 | cpu_cap = capacity_orig_of(cpu); | |
519 | ||
520 | return cpu_cap >= min(min_cap, max_cap); | |
521 | } | |
522 | #else | |
523 | static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) | |
524 | { | |
525 | return true; | |
526 | } | |
527 | #endif | |
528 | ||
052f1dc7 | 529 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 530 | |
9f0c1e56 | 531 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
532 | { |
533 | if (!rt_rq->tg) | |
9f0c1e56 | 534 | return RUNTIME_INF; |
6f505b16 | 535 | |
ac086bc2 PZ |
536 | return rt_rq->rt_runtime; |
537 | } | |
538 | ||
539 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
540 | { | |
541 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
542 | } |
543 | ||
ec514c48 CX |
544 | typedef struct task_group *rt_rq_iter_t; |
545 | ||
1c09ab0d YZ |
546 | static inline struct task_group *next_task_group(struct task_group *tg) |
547 | { | |
548 | do { | |
549 | tg = list_entry_rcu(tg->list.next, | |
550 | typeof(struct task_group), list); | |
551 | } while (&tg->list != &task_groups && task_group_is_autogroup(tg)); | |
552 | ||
553 | if (&tg->list == &task_groups) | |
554 | tg = NULL; | |
555 | ||
556 | return tg; | |
557 | } | |
558 | ||
559 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
560 | for (iter = container_of(&task_groups, typeof(*iter), list); \ | |
561 | (iter = next_task_group(iter)) && \ | |
562 | (rt_rq = iter->rt_rq[cpu_of(rq)]);) | |
ec514c48 | 563 | |
6f505b16 PZ |
564 | #define for_each_sched_rt_entity(rt_se) \ |
565 | for (; rt_se; rt_se = rt_se->parent) | |
566 | ||
567 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
568 | { | |
569 | return rt_se->my_q; | |
570 | } | |
571 | ||
ff77e468 PZ |
572 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); |
573 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); | |
6f505b16 | 574 | |
9f0c1e56 | 575 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 576 | { |
f6121f4f | 577 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
8875125e | 578 | struct rq *rq = rq_of_rt_rq(rt_rq); |
74b7eb58 YZ |
579 | struct sched_rt_entity *rt_se; |
580 | ||
8875125e | 581 | int cpu = cpu_of(rq); |
0c3b9168 BS |
582 | |
583 | rt_se = rt_rq->tg->rt_se[cpu]; | |
6f505b16 | 584 | |
f6121f4f | 585 | if (rt_rq->rt_nr_running) { |
f4ebcbc0 KT |
586 | if (!rt_se) |
587 | enqueue_top_rt_rq(rt_rq); | |
588 | else if (!on_rt_rq(rt_se)) | |
ff77e468 | 589 | enqueue_rt_entity(rt_se, 0); |
f4ebcbc0 | 590 | |
e864c499 | 591 | if (rt_rq->highest_prio.curr < curr->prio) |
8875125e | 592 | resched_curr(rq); |
6f505b16 PZ |
593 | } |
594 | } | |
595 | ||
9f0c1e56 | 596 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 597 | { |
74b7eb58 | 598 | struct sched_rt_entity *rt_se; |
0c3b9168 | 599 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
74b7eb58 | 600 | |
0c3b9168 | 601 | rt_se = rt_rq->tg->rt_se[cpu]; |
6f505b16 | 602 | |
296b2ffe | 603 | if (!rt_se) { |
5c66d1b9 | 604 | dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); |
296b2ffe VG |
605 | /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ |
606 | cpufreq_update_util(rq_of_rt_rq(rt_rq), 0); | |
607 | } | |
f4ebcbc0 | 608 | else if (on_rt_rq(rt_se)) |
ff77e468 | 609 | dequeue_rt_entity(rt_se, 0); |
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 && !rt_rq->rt_nr_boosted; | |
615 | } | |
616 | ||
23b0fdfc PZ |
617 | static int rt_se_boosted(struct sched_rt_entity *rt_se) |
618 | { | |
619 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
620 | struct task_struct *p; | |
621 | ||
622 | if (rt_rq) | |
623 | return !!rt_rq->rt_nr_boosted; | |
624 | ||
625 | p = rt_task_of(rt_se); | |
626 | return p->prio != p->normal_prio; | |
627 | } | |
628 | ||
d0b27fa7 | 629 | #ifdef CONFIG_SMP |
c6c4927b | 630 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 631 | { |
424c93fe | 632 | return this_rq()->rd->span; |
d0b27fa7 | 633 | } |
6f505b16 | 634 | #else |
c6c4927b | 635 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 636 | { |
c6c4927b | 637 | return cpu_online_mask; |
d0b27fa7 PZ |
638 | } |
639 | #endif | |
6f505b16 | 640 | |
d0b27fa7 PZ |
641 | static inline |
642 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 643 | { |
d0b27fa7 PZ |
644 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
645 | } | |
9f0c1e56 | 646 | |
ac086bc2 PZ |
647 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
648 | { | |
649 | return &rt_rq->tg->rt_bandwidth; | |
650 | } | |
651 | ||
55e12e5e | 652 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
653 | |
654 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
655 | { | |
ac086bc2 PZ |
656 | return rt_rq->rt_runtime; |
657 | } | |
658 | ||
659 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
660 | { | |
661 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
662 | } |
663 | ||
ec514c48 CX |
664 | typedef struct rt_rq *rt_rq_iter_t; |
665 | ||
666 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
667 | for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
668 | ||
6f505b16 PZ |
669 | #define for_each_sched_rt_entity(rt_se) \ |
670 | for (; rt_se; rt_se = NULL) | |
671 | ||
672 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
673 | { | |
674 | return NULL; | |
675 | } | |
676 | ||
9f0c1e56 | 677 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 678 | { |
f4ebcbc0 KT |
679 | struct rq *rq = rq_of_rt_rq(rt_rq); |
680 | ||
681 | if (!rt_rq->rt_nr_running) | |
682 | return; | |
683 | ||
684 | enqueue_top_rt_rq(rt_rq); | |
8875125e | 685 | resched_curr(rq); |
6f505b16 PZ |
686 | } |
687 | ||
9f0c1e56 | 688 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 689 | { |
5c66d1b9 | 690 | dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); |
6f505b16 PZ |
691 | } |
692 | ||
46383648 KT |
693 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
694 | { | |
695 | return rt_rq->rt_throttled; | |
696 | } | |
697 | ||
c6c4927b | 698 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 699 | { |
c6c4927b | 700 | return cpu_online_mask; |
d0b27fa7 PZ |
701 | } |
702 | ||
703 | static inline | |
704 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
705 | { | |
706 | return &cpu_rq(cpu)->rt; | |
707 | } | |
708 | ||
ac086bc2 PZ |
709 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
710 | { | |
711 | return &def_rt_bandwidth; | |
712 | } | |
713 | ||
55e12e5e | 714 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 715 | |
faa59937 JL |
716 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) |
717 | { | |
718 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
719 | ||
720 | return (hrtimer_active(&rt_b->rt_period_timer) || | |
721 | rt_rq->rt_time < rt_b->rt_runtime); | |
722 | } | |
723 | ||
ac086bc2 | 724 | #ifdef CONFIG_SMP |
78333cdd PZ |
725 | /* |
726 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
727 | */ | |
269b26a5 | 728 | static void do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
729 | { |
730 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
aa7f6730 | 731 | struct root_domain *rd = rq_of_rt_rq(rt_rq)->rd; |
269b26a5 | 732 | int i, weight; |
ac086bc2 PZ |
733 | u64 rt_period; |
734 | ||
c6c4927b | 735 | weight = cpumask_weight(rd->span); |
ac086bc2 | 736 | |
0986b11b | 737 | raw_spin_lock(&rt_b->rt_runtime_lock); |
ac086bc2 | 738 | rt_period = ktime_to_ns(rt_b->rt_period); |
c6c4927b | 739 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
740 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
741 | s64 diff; | |
742 | ||
743 | if (iter == rt_rq) | |
744 | continue; | |
745 | ||
0986b11b | 746 | raw_spin_lock(&iter->rt_runtime_lock); |
78333cdd PZ |
747 | /* |
748 | * Either all rqs have inf runtime and there's nothing to steal | |
749 | * or __disable_runtime() below sets a specific rq to inf to | |
3b03706f | 750 | * indicate its been disabled and disallow stealing. |
78333cdd | 751 | */ |
7def2be1 PZ |
752 | if (iter->rt_runtime == RUNTIME_INF) |
753 | goto next; | |
754 | ||
78333cdd PZ |
755 | /* |
756 | * From runqueues with spare time, take 1/n part of their | |
757 | * spare time, but no more than our period. | |
758 | */ | |
ac086bc2 PZ |
759 | diff = iter->rt_runtime - iter->rt_time; |
760 | if (diff > 0) { | |
58838cf3 | 761 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
762 | if (rt_rq->rt_runtime + diff > rt_period) |
763 | diff = rt_period - rt_rq->rt_runtime; | |
764 | iter->rt_runtime -= diff; | |
765 | rt_rq->rt_runtime += diff; | |
ac086bc2 | 766 | if (rt_rq->rt_runtime == rt_period) { |
0986b11b | 767 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 PZ |
768 | break; |
769 | } | |
770 | } | |
7def2be1 | 771 | next: |
0986b11b | 772 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 | 773 | } |
0986b11b | 774 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
ac086bc2 | 775 | } |
7def2be1 | 776 | |
78333cdd PZ |
777 | /* |
778 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
779 | */ | |
7def2be1 PZ |
780 | static void __disable_runtime(struct rq *rq) |
781 | { | |
782 | struct root_domain *rd = rq->rd; | |
ec514c48 | 783 | rt_rq_iter_t iter; |
7def2be1 PZ |
784 | struct rt_rq *rt_rq; |
785 | ||
786 | if (unlikely(!scheduler_running)) | |
787 | return; | |
788 | ||
ec514c48 | 789 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
790 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
791 | s64 want; | |
792 | int i; | |
793 | ||
0986b11b TG |
794 | raw_spin_lock(&rt_b->rt_runtime_lock); |
795 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
796 | /* |
797 | * Either we're all inf and nobody needs to borrow, or we're | |
798 | * already disabled and thus have nothing to do, or we have | |
799 | * exactly the right amount of runtime to take out. | |
800 | */ | |
7def2be1 PZ |
801 | if (rt_rq->rt_runtime == RUNTIME_INF || |
802 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
803 | goto balanced; | |
0986b11b | 804 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
7def2be1 | 805 | |
78333cdd PZ |
806 | /* |
807 | * Calculate the difference between what we started out with | |
808 | * and what we current have, that's the amount of runtime | |
809 | * we lend and now have to reclaim. | |
810 | */ | |
7def2be1 PZ |
811 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
812 | ||
78333cdd PZ |
813 | /* |
814 | * Greedy reclaim, take back as much as we can. | |
815 | */ | |
c6c4927b | 816 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
817 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
818 | s64 diff; | |
819 | ||
78333cdd PZ |
820 | /* |
821 | * Can't reclaim from ourselves or disabled runqueues. | |
822 | */ | |
f1679d08 | 823 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
824 | continue; |
825 | ||
0986b11b | 826 | raw_spin_lock(&iter->rt_runtime_lock); |
7def2be1 PZ |
827 | if (want > 0) { |
828 | diff = min_t(s64, iter->rt_runtime, want); | |
829 | iter->rt_runtime -= diff; | |
830 | want -= diff; | |
831 | } else { | |
832 | iter->rt_runtime -= want; | |
833 | want -= want; | |
834 | } | |
0986b11b | 835 | raw_spin_unlock(&iter->rt_runtime_lock); |
7def2be1 PZ |
836 | |
837 | if (!want) | |
838 | break; | |
839 | } | |
840 | ||
0986b11b | 841 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
78333cdd PZ |
842 | /* |
843 | * We cannot be left wanting - that would mean some runtime | |
844 | * leaked out of the system. | |
845 | */ | |
09348d75 | 846 | WARN_ON_ONCE(want); |
7def2be1 | 847 | balanced: |
78333cdd PZ |
848 | /* |
849 | * Disable all the borrow logic by pretending we have inf | |
850 | * runtime - in which case borrowing doesn't make sense. | |
851 | */ | |
7def2be1 | 852 | rt_rq->rt_runtime = RUNTIME_INF; |
a4c96ae3 | 853 | rt_rq->rt_throttled = 0; |
0986b11b TG |
854 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
855 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
99b62567 KT |
856 | |
857 | /* Make rt_rq available for pick_next_task() */ | |
858 | sched_rt_rq_enqueue(rt_rq); | |
7def2be1 PZ |
859 | } |
860 | } | |
861 | ||
7def2be1 PZ |
862 | static void __enable_runtime(struct rq *rq) |
863 | { | |
ec514c48 | 864 | rt_rq_iter_t iter; |
7def2be1 PZ |
865 | struct rt_rq *rt_rq; |
866 | ||
867 | if (unlikely(!scheduler_running)) | |
868 | return; | |
869 | ||
78333cdd PZ |
870 | /* |
871 | * Reset each runqueue's bandwidth settings | |
872 | */ | |
ec514c48 | 873 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
874 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
875 | ||
0986b11b TG |
876 | raw_spin_lock(&rt_b->rt_runtime_lock); |
877 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
7def2be1 PZ |
878 | rt_rq->rt_runtime = rt_b->rt_runtime; |
879 | rt_rq->rt_time = 0; | |
baf25731 | 880 | rt_rq->rt_throttled = 0; |
0986b11b TG |
881 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
882 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
883 | } |
884 | } | |
885 | ||
269b26a5 | 886 | static void balance_runtime(struct rt_rq *rt_rq) |
eff6549b | 887 | { |
4a6184ce | 888 | if (!sched_feat(RT_RUNTIME_SHARE)) |
269b26a5 | 889 | return; |
4a6184ce | 890 | |
eff6549b | 891 | if (rt_rq->rt_time > rt_rq->rt_runtime) { |
0986b11b | 892 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
269b26a5 | 893 | do_balance_runtime(rt_rq); |
0986b11b | 894 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b | 895 | } |
eff6549b | 896 | } |
55e12e5e | 897 | #else /* !CONFIG_SMP */ |
269b26a5 | 898 | static inline void balance_runtime(struct rt_rq *rt_rq) {} |
55e12e5e | 899 | #endif /* CONFIG_SMP */ |
ac086bc2 | 900 | |
eff6549b PZ |
901 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
902 | { | |
42c62a58 | 903 | int i, idle = 1, throttled = 0; |
c6c4927b | 904 | const struct cpumask *span; |
eff6549b | 905 | |
eff6549b | 906 | span = sched_rt_period_mask(); |
e221d028 MG |
907 | #ifdef CONFIG_RT_GROUP_SCHED |
908 | /* | |
909 | * FIXME: isolated CPUs should really leave the root task group, | |
910 | * whether they are isolcpus or were isolated via cpusets, lest | |
911 | * the timer run on a CPU which does not service all runqueues, | |
912 | * potentially leaving other CPUs indefinitely throttled. If | |
913 | * isolation is really required, the user will turn the throttle | |
914 | * off to kill the perturbations it causes anyway. Meanwhile, | |
915 | * this maintains functionality for boot and/or troubleshooting. | |
916 | */ | |
917 | if (rt_b == &root_task_group.rt_bandwidth) | |
918 | span = cpu_online_mask; | |
919 | #endif | |
c6c4927b | 920 | for_each_cpu(i, span) { |
eff6549b PZ |
921 | int enqueue = 0; |
922 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
923 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
2679a837 | 924 | struct rq_flags rf; |
c249f255 DK |
925 | int skip; |
926 | ||
927 | /* | |
928 | * When span == cpu_online_mask, taking each rq->lock | |
929 | * can be time-consuming. Try to avoid it when possible. | |
930 | */ | |
931 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
f3d133ee HL |
932 | if (!sched_feat(RT_RUNTIME_SHARE) && rt_rq->rt_runtime != RUNTIME_INF) |
933 | rt_rq->rt_runtime = rt_b->rt_runtime; | |
c249f255 DK |
934 | skip = !rt_rq->rt_time && !rt_rq->rt_nr_running; |
935 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
936 | if (skip) | |
937 | continue; | |
eff6549b | 938 | |
2679a837 | 939 | rq_lock(rq, &rf); |
d29a2064 DB |
940 | update_rq_clock(rq); |
941 | ||
eff6549b PZ |
942 | if (rt_rq->rt_time) { |
943 | u64 runtime; | |
944 | ||
0986b11b | 945 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
946 | if (rt_rq->rt_throttled) |
947 | balance_runtime(rt_rq); | |
948 | runtime = rt_rq->rt_runtime; | |
949 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
950 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
951 | rt_rq->rt_throttled = 0; | |
952 | enqueue = 1; | |
61eadef6 MG |
953 | |
954 | /* | |
9edfbfed PZ |
955 | * When we're idle and a woken (rt) task is |
956 | * throttled check_preempt_curr() will set | |
957 | * skip_update and the time between the wakeup | |
958 | * and this unthrottle will get accounted as | |
959 | * 'runtime'. | |
61eadef6 MG |
960 | */ |
961 | if (rt_rq->rt_nr_running && rq->curr == rq->idle) | |
adcc8da8 | 962 | rq_clock_cancel_skipupdate(rq); |
eff6549b PZ |
963 | } |
964 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
965 | idle = 0; | |
0986b11b | 966 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
0c3b9168 | 967 | } else if (rt_rq->rt_nr_running) { |
6c3df255 | 968 | idle = 0; |
0c3b9168 BS |
969 | if (!rt_rq_throttled(rt_rq)) |
970 | enqueue = 1; | |
971 | } | |
42c62a58 PZ |
972 | if (rt_rq->rt_throttled) |
973 | throttled = 1; | |
eff6549b PZ |
974 | |
975 | if (enqueue) | |
976 | sched_rt_rq_enqueue(rt_rq); | |
2679a837 | 977 | rq_unlock(rq, &rf); |
eff6549b PZ |
978 | } |
979 | ||
42c62a58 PZ |
980 | if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) |
981 | return 1; | |
982 | ||
eff6549b PZ |
983 | return idle; |
984 | } | |
ac086bc2 | 985 | |
6f505b16 PZ |
986 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
987 | { | |
052f1dc7 | 988 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
989 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
990 | ||
991 | if (rt_rq) | |
e864c499 | 992 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
993 | #endif |
994 | ||
995 | return rt_task_of(rt_se)->prio; | |
996 | } | |
997 | ||
9f0c1e56 | 998 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 999 | { |
9f0c1e56 | 1000 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 1001 | |
fa85ae24 | 1002 | if (rt_rq->rt_throttled) |
23b0fdfc | 1003 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 1004 | |
5b680fd6 | 1005 | if (runtime >= sched_rt_period(rt_rq)) |
ac086bc2 PZ |
1006 | return 0; |
1007 | ||
b79f3833 PZ |
1008 | balance_runtime(rt_rq); |
1009 | runtime = sched_rt_runtime(rt_rq); | |
1010 | if (runtime == RUNTIME_INF) | |
1011 | return 0; | |
ac086bc2 | 1012 | |
9f0c1e56 | 1013 | if (rt_rq->rt_time > runtime) { |
7abc63b1 PZ |
1014 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
1015 | ||
1016 | /* | |
1017 | * Don't actually throttle groups that have no runtime assigned | |
1018 | * but accrue some time due to boosting. | |
1019 | */ | |
1020 | if (likely(rt_b->rt_runtime)) { | |
1021 | rt_rq->rt_throttled = 1; | |
c224815d | 1022 | printk_deferred_once("sched: RT throttling activated\n"); |
7abc63b1 PZ |
1023 | } else { |
1024 | /* | |
1025 | * In case we did anyway, make it go away, | |
1026 | * replenishment is a joke, since it will replenish us | |
1027 | * with exactly 0 ns. | |
1028 | */ | |
1029 | rt_rq->rt_time = 0; | |
1030 | } | |
1031 | ||
23b0fdfc | 1032 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 1033 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
1034 | return 1; |
1035 | } | |
fa85ae24 PZ |
1036 | } |
1037 | ||
1038 | return 0; | |
1039 | } | |
1040 | ||
bb44e5d1 IM |
1041 | /* |
1042 | * Update the current task's runtime statistics. Skip current tasks that | |
1043 | * are not in our scheduling class. | |
1044 | */ | |
a9957449 | 1045 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
1046 | { |
1047 | struct task_struct *curr = rq->curr; | |
6f505b16 | 1048 | struct sched_rt_entity *rt_se = &curr->rt; |
bb44e5d1 | 1049 | u64 delta_exec; |
a7711602 | 1050 | u64 now; |
bb44e5d1 | 1051 | |
06c3bc65 | 1052 | if (curr->sched_class != &rt_sched_class) |
bb44e5d1 IM |
1053 | return; |
1054 | ||
a7711602 | 1055 | now = rq_clock_task(rq); |
e7ad2031 | 1056 | delta_exec = now - curr->se.exec_start; |
fc79e240 KT |
1057 | if (unlikely((s64)delta_exec <= 0)) |
1058 | return; | |
6cfb0d5d | 1059 | |
ceeadb83 YS |
1060 | schedstat_set(curr->stats.exec_max, |
1061 | max(curr->stats.exec_max, delta_exec)); | |
bb44e5d1 | 1062 | |
ed7b564c YS |
1063 | trace_sched_stat_runtime(curr, delta_exec, 0); |
1064 | ||
5531ecff | 1065 | update_current_exec_runtime(curr, now, delta_exec); |
fa85ae24 | 1066 | |
0b148fa0 PZ |
1067 | if (!rt_bandwidth_enabled()) |
1068 | return; | |
1069 | ||
354d60c2 | 1070 | for_each_sched_rt_entity(rt_se) { |
0b07939c | 1071 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
9b58e976 | 1072 | int exceeded; |
354d60c2 | 1073 | |
cc2991cf | 1074 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
0986b11b | 1075 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf | 1076 | rt_rq->rt_time += delta_exec; |
9b58e976 LH |
1077 | exceeded = sched_rt_runtime_exceeded(rt_rq); |
1078 | if (exceeded) | |
8875125e | 1079 | resched_curr(rq); |
0986b11b | 1080 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
9b58e976 LH |
1081 | if (exceeded) |
1082 | do_start_rt_bandwidth(sched_rt_bandwidth(rt_rq)); | |
cc2991cf | 1083 | } |
354d60c2 | 1084 | } |
bb44e5d1 IM |
1085 | } |
1086 | ||
f4ebcbc0 | 1087 | static void |
5c66d1b9 | 1088 | dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count) |
f4ebcbc0 KT |
1089 | { |
1090 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1091 | ||
1092 | BUG_ON(&rq->rt != rt_rq); | |
1093 | ||
1094 | if (!rt_rq->rt_queued) | |
1095 | return; | |
1096 | ||
1097 | BUG_ON(!rq->nr_running); | |
1098 | ||
5c66d1b9 | 1099 | sub_nr_running(rq, count); |
f4ebcbc0 | 1100 | rt_rq->rt_queued = 0; |
8f111bc3 | 1101 | |
f4ebcbc0 KT |
1102 | } |
1103 | ||
1104 | static void | |
1105 | enqueue_top_rt_rq(struct rt_rq *rt_rq) | |
1106 | { | |
1107 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1108 | ||
1109 | BUG_ON(&rq->rt != rt_rq); | |
1110 | ||
1111 | if (rt_rq->rt_queued) | |
1112 | return; | |
296b2ffe VG |
1113 | |
1114 | if (rt_rq_throttled(rt_rq)) | |
f4ebcbc0 KT |
1115 | return; |
1116 | ||
296b2ffe VG |
1117 | if (rt_rq->rt_nr_running) { |
1118 | add_nr_running(rq, rt_rq->rt_nr_running); | |
1119 | rt_rq->rt_queued = 1; | |
1120 | } | |
8f111bc3 PZ |
1121 | |
1122 | /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ | |
1123 | cpufreq_update_util(rq, 0); | |
f4ebcbc0 KT |
1124 | } |
1125 | ||
398a153b | 1126 | #if defined CONFIG_SMP |
e864c499 | 1127 | |
398a153b GH |
1128 | static void |
1129 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 1130 | { |
4d984277 | 1131 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 1132 | |
757dfcaa KT |
1133 | #ifdef CONFIG_RT_GROUP_SCHED |
1134 | /* | |
1135 | * Change rq's cpupri only if rt_rq is the top queue. | |
1136 | */ | |
1137 | if (&rq->rt != rt_rq) | |
1138 | return; | |
1139 | #endif | |
5181f4a4 SR |
1140 | if (rq->online && prio < prev_prio) |
1141 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); | |
398a153b | 1142 | } |
73fe6aae | 1143 | |
398a153b GH |
1144 | static void |
1145 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
1146 | { | |
1147 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 1148 | |
757dfcaa KT |
1149 | #ifdef CONFIG_RT_GROUP_SCHED |
1150 | /* | |
1151 | * Change rq's cpupri only if rt_rq is the top queue. | |
1152 | */ | |
1153 | if (&rq->rt != rt_rq) | |
1154 | return; | |
1155 | #endif | |
398a153b GH |
1156 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) |
1157 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
1158 | } |
1159 | ||
398a153b GH |
1160 | #else /* CONFIG_SMP */ |
1161 | ||
6f505b16 | 1162 | static inline |
398a153b GH |
1163 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
1164 | static inline | |
1165 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
1166 | ||
1167 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 1168 | |
052f1dc7 | 1169 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
1170 | static void |
1171 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
1172 | { | |
1173 | int prev_prio = rt_rq->highest_prio.curr; | |
1174 | ||
1175 | if (prio < prev_prio) | |
1176 | rt_rq->highest_prio.curr = prio; | |
1177 | ||
1178 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
1179 | } | |
1180 | ||
1181 | static void | |
1182 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
1183 | { | |
1184 | int prev_prio = rt_rq->highest_prio.curr; | |
1185 | ||
6f505b16 | 1186 | if (rt_rq->rt_nr_running) { |
764a9d6f | 1187 | |
398a153b | 1188 | WARN_ON(prio < prev_prio); |
764a9d6f | 1189 | |
e864c499 | 1190 | /* |
398a153b GH |
1191 | * This may have been our highest task, and therefore |
1192 | * we may have some recomputation to do | |
e864c499 | 1193 | */ |
398a153b | 1194 | if (prio == prev_prio) { |
e864c499 GH |
1195 | struct rt_prio_array *array = &rt_rq->active; |
1196 | ||
1197 | rt_rq->highest_prio.curr = | |
764a9d6f | 1198 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
1199 | } |
1200 | ||
934fc331 PZ |
1201 | } else { |
1202 | rt_rq->highest_prio.curr = MAX_RT_PRIO-1; | |
1203 | } | |
73fe6aae | 1204 | |
398a153b GH |
1205 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
1206 | } | |
1f11eb6a | 1207 | |
398a153b GH |
1208 | #else |
1209 | ||
1210 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1211 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1212 | ||
1213 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 1214 | |
052f1dc7 | 1215 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
1216 | |
1217 | static void | |
1218 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1219 | { | |
1220 | if (rt_se_boosted(rt_se)) | |
1221 | rt_rq->rt_nr_boosted++; | |
1222 | ||
1223 | if (rt_rq->tg) | |
1224 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
1225 | } | |
1226 | ||
1227 | static void | |
1228 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1229 | { | |
23b0fdfc PZ |
1230 | if (rt_se_boosted(rt_se)) |
1231 | rt_rq->rt_nr_boosted--; | |
1232 | ||
1233 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
398a153b GH |
1234 | } |
1235 | ||
1236 | #else /* CONFIG_RT_GROUP_SCHED */ | |
1237 | ||
1238 | static void | |
1239 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1240 | { | |
1241 | start_rt_bandwidth(&def_rt_bandwidth); | |
1242 | } | |
1243 | ||
1244 | static inline | |
1245 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
1246 | ||
1247 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
1248 | ||
22abdef3 KT |
1249 | static inline |
1250 | unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se) | |
1251 | { | |
1252 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1253 | ||
1254 | if (group_rq) | |
1255 | return group_rq->rt_nr_running; | |
1256 | else | |
1257 | return 1; | |
1258 | } | |
1259 | ||
01d36d0a FW |
1260 | static inline |
1261 | unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se) | |
1262 | { | |
1263 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1264 | struct task_struct *tsk; | |
1265 | ||
1266 | if (group_rq) | |
1267 | return group_rq->rr_nr_running; | |
1268 | ||
1269 | tsk = rt_task_of(rt_se); | |
1270 | ||
1271 | return (tsk->policy == SCHED_RR) ? 1 : 0; | |
1272 | } | |
1273 | ||
398a153b GH |
1274 | static inline |
1275 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1276 | { | |
1277 | int prio = rt_se_prio(rt_se); | |
1278 | ||
1279 | WARN_ON(!rt_prio(prio)); | |
22abdef3 | 1280 | rt_rq->rt_nr_running += rt_se_nr_running(rt_se); |
01d36d0a | 1281 | rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se); |
398a153b GH |
1282 | |
1283 | inc_rt_prio(rt_rq, prio); | |
1284 | inc_rt_migration(rt_se, rt_rq); | |
1285 | inc_rt_group(rt_se, rt_rq); | |
1286 | } | |
1287 | ||
1288 | static inline | |
1289 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1290 | { | |
1291 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
1292 | WARN_ON(!rt_rq->rt_nr_running); | |
22abdef3 | 1293 | rt_rq->rt_nr_running -= rt_se_nr_running(rt_se); |
01d36d0a | 1294 | rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se); |
398a153b GH |
1295 | |
1296 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
1297 | dec_rt_migration(rt_se, rt_rq); | |
1298 | dec_rt_group(rt_se, rt_rq); | |
63489e45 SR |
1299 | } |
1300 | ||
ff77e468 PZ |
1301 | /* |
1302 | * Change rt_se->run_list location unless SAVE && !MOVE | |
1303 | * | |
1304 | * assumes ENQUEUE/DEQUEUE flags match | |
1305 | */ | |
1306 | static inline bool move_entity(unsigned int flags) | |
1307 | { | |
1308 | if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE) | |
1309 | return false; | |
1310 | ||
1311 | return true; | |
1312 | } | |
1313 | ||
1314 | static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array) | |
1315 | { | |
1316 | list_del_init(&rt_se->run_list); | |
1317 | ||
1318 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
1319 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
1320 | ||
1321 | rt_se->on_list = 0; | |
1322 | } | |
1323 | ||
57a5c2da YS |
1324 | static inline struct sched_statistics * |
1325 | __schedstats_from_rt_se(struct sched_rt_entity *rt_se) | |
1326 | { | |
1327 | #ifdef CONFIG_RT_GROUP_SCHED | |
1328 | /* schedstats is not supported for rt group. */ | |
1329 | if (!rt_entity_is_task(rt_se)) | |
1330 | return NULL; | |
1331 | #endif | |
1332 | ||
1333 | return &rt_task_of(rt_se)->stats; | |
1334 | } | |
1335 | ||
1336 | static inline void | |
1337 | update_stats_wait_start_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) | |
1338 | { | |
1339 | struct sched_statistics *stats; | |
1340 | struct task_struct *p = NULL; | |
1341 | ||
1342 | if (!schedstat_enabled()) | |
1343 | return; | |
1344 | ||
1345 | if (rt_entity_is_task(rt_se)) | |
1346 | p = rt_task_of(rt_se); | |
1347 | ||
1348 | stats = __schedstats_from_rt_se(rt_se); | |
1349 | if (!stats) | |
1350 | return; | |
1351 | ||
1352 | __update_stats_wait_start(rq_of_rt_rq(rt_rq), p, stats); | |
1353 | } | |
1354 | ||
1355 | static inline void | |
1356 | update_stats_enqueue_sleeper_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) | |
1357 | { | |
1358 | struct sched_statistics *stats; | |
1359 | struct task_struct *p = NULL; | |
1360 | ||
1361 | if (!schedstat_enabled()) | |
1362 | return; | |
1363 | ||
1364 | if (rt_entity_is_task(rt_se)) | |
1365 | p = rt_task_of(rt_se); | |
1366 | ||
1367 | stats = __schedstats_from_rt_se(rt_se); | |
1368 | if (!stats) | |
1369 | return; | |
1370 | ||
1371 | __update_stats_enqueue_sleeper(rq_of_rt_rq(rt_rq), p, stats); | |
1372 | } | |
1373 | ||
1374 | static inline void | |
1375 | update_stats_enqueue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, | |
1376 | int flags) | |
1377 | { | |
1378 | if (!schedstat_enabled()) | |
1379 | return; | |
1380 | ||
1381 | if (flags & ENQUEUE_WAKEUP) | |
1382 | update_stats_enqueue_sleeper_rt(rt_rq, rt_se); | |
1383 | } | |
1384 | ||
1385 | static inline void | |
1386 | update_stats_wait_end_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) | |
1387 | { | |
1388 | struct sched_statistics *stats; | |
1389 | struct task_struct *p = NULL; | |
1390 | ||
1391 | if (!schedstat_enabled()) | |
1392 | return; | |
1393 | ||
1394 | if (rt_entity_is_task(rt_se)) | |
1395 | p = rt_task_of(rt_se); | |
1396 | ||
1397 | stats = __schedstats_from_rt_se(rt_se); | |
1398 | if (!stats) | |
1399 | return; | |
1400 | ||
1401 | __update_stats_wait_end(rq_of_rt_rq(rt_rq), p, stats); | |
1402 | } | |
1403 | ||
1404 | static inline void | |
1405 | update_stats_dequeue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, | |
1406 | int flags) | |
1407 | { | |
1408 | struct task_struct *p = NULL; | |
1409 | ||
1410 | if (!schedstat_enabled()) | |
1411 | return; | |
1412 | ||
1413 | if (rt_entity_is_task(rt_se)) | |
1414 | p = rt_task_of(rt_se); | |
1415 | ||
1416 | if ((flags & DEQUEUE_SLEEP) && p) { | |
1417 | unsigned int state; | |
1418 | ||
1419 | state = READ_ONCE(p->__state); | |
1420 | if (state & TASK_INTERRUPTIBLE) | |
1421 | __schedstat_set(p->stats.sleep_start, | |
1422 | rq_clock(rq_of_rt_rq(rt_rq))); | |
1423 | ||
1424 | if (state & TASK_UNINTERRUPTIBLE) | |
1425 | __schedstat_set(p->stats.block_start, | |
1426 | rq_clock(rq_of_rt_rq(rt_rq))); | |
1427 | } | |
1428 | } | |
1429 | ||
ff77e468 | 1430 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
bb44e5d1 | 1431 | { |
6f505b16 PZ |
1432 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
1433 | struct rt_prio_array *array = &rt_rq->active; | |
1434 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 1435 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 1436 | |
ad2a3f13 PZ |
1437 | /* |
1438 | * Don't enqueue the group if its throttled, or when empty. | |
1439 | * The latter is a consequence of the former when a child group | |
1440 | * get throttled and the current group doesn't have any other | |
1441 | * active members. | |
1442 | */ | |
ff77e468 PZ |
1443 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) { |
1444 | if (rt_se->on_list) | |
1445 | __delist_rt_entity(rt_se, array); | |
6f505b16 | 1446 | return; |
ff77e468 | 1447 | } |
63489e45 | 1448 | |
ff77e468 PZ |
1449 | if (move_entity(flags)) { |
1450 | WARN_ON_ONCE(rt_se->on_list); | |
1451 | if (flags & ENQUEUE_HEAD) | |
1452 | list_add(&rt_se->run_list, queue); | |
1453 | else | |
1454 | list_add_tail(&rt_se->run_list, queue); | |
1455 | ||
1456 | __set_bit(rt_se_prio(rt_se), array->bitmap); | |
1457 | rt_se->on_list = 1; | |
1458 | } | |
1459 | rt_se->on_rq = 1; | |
78f2c7db | 1460 | |
6f505b16 PZ |
1461 | inc_rt_tasks(rt_se, rt_rq); |
1462 | } | |
1463 | ||
ff77e468 | 1464 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
6f505b16 PZ |
1465 | { |
1466 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
1467 | struct rt_prio_array *array = &rt_rq->active; | |
1468 | ||
ff77e468 PZ |
1469 | if (move_entity(flags)) { |
1470 | WARN_ON_ONCE(!rt_se->on_list); | |
1471 | __delist_rt_entity(rt_se, array); | |
1472 | } | |
1473 | rt_se->on_rq = 0; | |
6f505b16 PZ |
1474 | |
1475 | dec_rt_tasks(rt_se, rt_rq); | |
1476 | } | |
1477 | ||
1478 | /* | |
1479 | * Because the prio of an upper entry depends on the lower | |
1480 | * entries, we must remove entries top - down. | |
6f505b16 | 1481 | */ |
ff77e468 | 1482 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags) |
6f505b16 | 1483 | { |
ad2a3f13 | 1484 | struct sched_rt_entity *back = NULL; |
5c66d1b9 | 1485 | unsigned int rt_nr_running; |
6f505b16 | 1486 | |
58d6c2d7 PZ |
1487 | for_each_sched_rt_entity(rt_se) { |
1488 | rt_se->back = back; | |
1489 | back = rt_se; | |
1490 | } | |
1491 | ||
5c66d1b9 | 1492 | rt_nr_running = rt_rq_of_se(back)->rt_nr_running; |
f4ebcbc0 | 1493 | |
58d6c2d7 PZ |
1494 | for (rt_se = back; rt_se; rt_se = rt_se->back) { |
1495 | if (on_rt_rq(rt_se)) | |
ff77e468 | 1496 | __dequeue_rt_entity(rt_se, flags); |
ad2a3f13 | 1497 | } |
5c66d1b9 NSJ |
1498 | |
1499 | dequeue_top_rt_rq(rt_rq_of_se(back), rt_nr_running); | |
ad2a3f13 PZ |
1500 | } |
1501 | ||
ff77e468 | 1502 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
ad2a3f13 | 1503 | { |
f4ebcbc0 KT |
1504 | struct rq *rq = rq_of_rt_se(rt_se); |
1505 | ||
57a5c2da YS |
1506 | update_stats_enqueue_rt(rt_rq_of_se(rt_se), rt_se, flags); |
1507 | ||
ff77e468 | 1508 | dequeue_rt_stack(rt_se, flags); |
ad2a3f13 | 1509 | for_each_sched_rt_entity(rt_se) |
ff77e468 | 1510 | __enqueue_rt_entity(rt_se, flags); |
f4ebcbc0 | 1511 | enqueue_top_rt_rq(&rq->rt); |
ad2a3f13 PZ |
1512 | } |
1513 | ||
ff77e468 | 1514 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
ad2a3f13 | 1515 | { |
f4ebcbc0 KT |
1516 | struct rq *rq = rq_of_rt_se(rt_se); |
1517 | ||
57a5c2da YS |
1518 | update_stats_dequeue_rt(rt_rq_of_se(rt_se), rt_se, flags); |
1519 | ||
ff77e468 | 1520 | dequeue_rt_stack(rt_se, flags); |
ad2a3f13 PZ |
1521 | |
1522 | for_each_sched_rt_entity(rt_se) { | |
1523 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
1524 | ||
1525 | if (rt_rq && rt_rq->rt_nr_running) | |
ff77e468 | 1526 | __enqueue_rt_entity(rt_se, flags); |
58d6c2d7 | 1527 | } |
f4ebcbc0 | 1528 | enqueue_top_rt_rq(&rq->rt); |
bb44e5d1 IM |
1529 | } |
1530 | ||
1531 | /* | |
1532 | * Adding/removing a task to/from a priority array: | |
1533 | */ | |
ea87bb78 | 1534 | static void |
371fd7e7 | 1535 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
6f505b16 PZ |
1536 | { |
1537 | struct sched_rt_entity *rt_se = &p->rt; | |
1538 | ||
371fd7e7 | 1539 | if (flags & ENQUEUE_WAKEUP) |
6f505b16 PZ |
1540 | rt_se->timeout = 0; |
1541 | ||
57a5c2da YS |
1542 | check_schedstat_required(); |
1543 | update_stats_wait_start_rt(rt_rq_of_se(rt_se), rt_se); | |
1544 | ||
ff77e468 | 1545 | enqueue_rt_entity(rt_se, flags); |
c09595f6 | 1546 | |
4b53a341 | 1547 | if (!task_current(rq, p) && p->nr_cpus_allowed > 1) |
917b627d | 1548 | enqueue_pushable_task(rq, p); |
6f505b16 PZ |
1549 | } |
1550 | ||
371fd7e7 | 1551 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1552 | { |
6f505b16 | 1553 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 1554 | |
f1e14ef6 | 1555 | update_curr_rt(rq); |
ff77e468 | 1556 | dequeue_rt_entity(rt_se, flags); |
c09595f6 | 1557 | |
917b627d | 1558 | dequeue_pushable_task(rq, p); |
bb44e5d1 IM |
1559 | } |
1560 | ||
1561 | /* | |
60686317 RW |
1562 | * Put task to the head or the end of the run list without the overhead of |
1563 | * dequeue followed by enqueue. | |
bb44e5d1 | 1564 | */ |
7ebefa8c DA |
1565 | static void |
1566 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 1567 | { |
1cdad715 | 1568 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
1569 | struct rt_prio_array *array = &rt_rq->active; |
1570 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
1571 | ||
1572 | if (head) | |
1573 | list_move(&rt_se->run_list, queue); | |
1574 | else | |
1575 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 1576 | } |
6f505b16 PZ |
1577 | } |
1578 | ||
7ebefa8c | 1579 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 1580 | { |
6f505b16 PZ |
1581 | struct sched_rt_entity *rt_se = &p->rt; |
1582 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1583 | |
6f505b16 PZ |
1584 | for_each_sched_rt_entity(rt_se) { |
1585 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 1586 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 1587 | } |
bb44e5d1 IM |
1588 | } |
1589 | ||
6f505b16 | 1590 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 1591 | { |
7ebefa8c | 1592 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
1593 | } |
1594 | ||
e7693a36 | 1595 | #ifdef CONFIG_SMP |
318e0893 GH |
1596 | static int find_lowest_rq(struct task_struct *task); |
1597 | ||
0017d735 | 1598 | static int |
3aef1551 | 1599 | select_task_rq_rt(struct task_struct *p, int cpu, int flags) |
e7693a36 | 1600 | { |
7608dec2 PZ |
1601 | struct task_struct *curr; |
1602 | struct rq *rq; | |
804d402f | 1603 | bool test; |
c37495fd SR |
1604 | |
1605 | /* For anything but wake ups, just return the task_cpu */ | |
3aef1551 | 1606 | if (!(flags & (WF_TTWU | WF_FORK))) |
c37495fd SR |
1607 | goto out; |
1608 | ||
7608dec2 PZ |
1609 | rq = cpu_rq(cpu); |
1610 | ||
1611 | rcu_read_lock(); | |
316c1608 | 1612 | curr = READ_ONCE(rq->curr); /* unlocked access */ |
7608dec2 | 1613 | |
318e0893 | 1614 | /* |
7608dec2 | 1615 | * If the current task on @p's runqueue is an RT task, then |
e1f47d89 SR |
1616 | * try to see if we can wake this RT task up on another |
1617 | * runqueue. Otherwise simply start this RT task | |
1618 | * on its current runqueue. | |
1619 | * | |
43fa5460 SR |
1620 | * We want to avoid overloading runqueues. If the woken |
1621 | * task is a higher priority, then it will stay on this CPU | |
1622 | * and the lower prio task should be moved to another CPU. | |
1623 | * Even though this will probably make the lower prio task | |
1624 | * lose its cache, we do not want to bounce a higher task | |
1625 | * around just because it gave up its CPU, perhaps for a | |
1626 | * lock? | |
1627 | * | |
1628 | * For equal prio tasks, we just let the scheduler sort it out. | |
7608dec2 PZ |
1629 | * |
1630 | * Otherwise, just let it ride on the affined RQ and the | |
1631 | * post-schedule router will push the preempted task away | |
1632 | * | |
1633 | * This test is optimistic, if we get it wrong the load-balancer | |
1634 | * will have to sort it out. | |
804d402f QY |
1635 | * |
1636 | * We take into account the capacity of the CPU to ensure it fits the | |
1637 | * requirement of the task - which is only important on heterogeneous | |
1638 | * systems like big.LITTLE. | |
318e0893 | 1639 | */ |
804d402f QY |
1640 | test = curr && |
1641 | unlikely(rt_task(curr)) && | |
1642 | (curr->nr_cpus_allowed < 2 || curr->prio <= p->prio); | |
1643 | ||
1644 | if (test || !rt_task_fits_capacity(p, cpu)) { | |
7608dec2 | 1645 | int target = find_lowest_rq(p); |
318e0893 | 1646 | |
b28bc1e0 QY |
1647 | /* |
1648 | * Bail out if we were forcing a migration to find a better | |
1649 | * fitting CPU but our search failed. | |
1650 | */ | |
1651 | if (!test && target != -1 && !rt_task_fits_capacity(p, target)) | |
1652 | goto out_unlock; | |
1653 | ||
80e3d87b TC |
1654 | /* |
1655 | * Don't bother moving it if the destination CPU is | |
1656 | * not running a lower priority task. | |
1657 | */ | |
1658 | if (target != -1 && | |
1659 | p->prio < cpu_rq(target)->rt.highest_prio.curr) | |
7608dec2 | 1660 | cpu = target; |
318e0893 | 1661 | } |
b28bc1e0 QY |
1662 | |
1663 | out_unlock: | |
7608dec2 | 1664 | rcu_read_unlock(); |
318e0893 | 1665 | |
c37495fd | 1666 | out: |
7608dec2 | 1667 | return cpu; |
e7693a36 | 1668 | } |
7ebefa8c DA |
1669 | |
1670 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1671 | { | |
308a623a WL |
1672 | /* |
1673 | * Current can't be migrated, useless to reschedule, | |
1674 | * let's hope p can move out. | |
1675 | */ | |
4b53a341 | 1676 | if (rq->curr->nr_cpus_allowed == 1 || |
a1bd02e1 | 1677 | !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) |
7ebefa8c DA |
1678 | return; |
1679 | ||
308a623a WL |
1680 | /* |
1681 | * p is migratable, so let's not schedule it and | |
1682 | * see if it is pushed or pulled somewhere else. | |
1683 | */ | |
804d402f | 1684 | if (p->nr_cpus_allowed != 1 && |
a1bd02e1 | 1685 | cpupri_find(&rq->rd->cpupri, p, NULL)) |
13b8bd0a | 1686 | return; |
24600ce8 | 1687 | |
7ebefa8c | 1688 | /* |
97fb7a0a IM |
1689 | * There appear to be other CPUs that can accept |
1690 | * the current task but none can run 'p', so lets reschedule | |
1691 | * to try and push the current task away: | |
7ebefa8c DA |
1692 | */ |
1693 | requeue_task_rt(rq, p, 1); | |
8875125e | 1694 | resched_curr(rq); |
7ebefa8c DA |
1695 | } |
1696 | ||
6e2df058 PZ |
1697 | static int balance_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf) |
1698 | { | |
1699 | if (!on_rt_rq(&p->rt) && need_pull_rt_task(rq, p)) { | |
1700 | /* | |
1701 | * This is OK, because current is on_cpu, which avoids it being | |
1702 | * picked for load-balance and preemption/IRQs are still | |
1703 | * disabled avoiding further scheduler activity on it and we've | |
1704 | * not yet started the picking loop. | |
1705 | */ | |
1706 | rq_unpin_lock(rq, rf); | |
1707 | pull_rt_task(rq); | |
1708 | rq_repin_lock(rq, rf); | |
1709 | } | |
1710 | ||
1711 | return sched_stop_runnable(rq) || sched_dl_runnable(rq) || sched_rt_runnable(rq); | |
1712 | } | |
e7693a36 GH |
1713 | #endif /* CONFIG_SMP */ |
1714 | ||
bb44e5d1 IM |
1715 | /* |
1716 | * Preempt the current task with a newly woken task if needed: | |
1717 | */ | |
7d478721 | 1718 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1719 | { |
45c01e82 | 1720 | if (p->prio < rq->curr->prio) { |
8875125e | 1721 | resched_curr(rq); |
45c01e82 GH |
1722 | return; |
1723 | } | |
1724 | ||
1725 | #ifdef CONFIG_SMP | |
1726 | /* | |
1727 | * If: | |
1728 | * | |
1729 | * - the newly woken task is of equal priority to the current task | |
1730 | * - the newly woken task is non-migratable while current is migratable | |
1731 | * - current will be preempted on the next reschedule | |
1732 | * | |
1733 | * we should check to see if current can readily move to a different | |
1734 | * cpu. If so, we will reschedule to allow the push logic to try | |
1735 | * to move current somewhere else, making room for our non-migratable | |
1736 | * task. | |
1737 | */ | |
8dd0de8b | 1738 | if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) |
7ebefa8c | 1739 | check_preempt_equal_prio(rq, p); |
45c01e82 | 1740 | #endif |
bb44e5d1 IM |
1741 | } |
1742 | ||
a0e813f2 | 1743 | static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool first) |
ff1cdc94 | 1744 | { |
57a5c2da YS |
1745 | struct sched_rt_entity *rt_se = &p->rt; |
1746 | struct rt_rq *rt_rq = &rq->rt; | |
1747 | ||
ff1cdc94 | 1748 | p->se.exec_start = rq_clock_task(rq); |
57a5c2da YS |
1749 | if (on_rt_rq(&p->rt)) |
1750 | update_stats_wait_end_rt(rt_rq, rt_se); | |
ff1cdc94 MS |
1751 | |
1752 | /* The running task is never eligible for pushing */ | |
1753 | dequeue_pushable_task(rq, p); | |
f95d4eae | 1754 | |
a0e813f2 PZ |
1755 | if (!first) |
1756 | return; | |
1757 | ||
f95d4eae PZ |
1758 | /* |
1759 | * If prev task was rt, put_prev_task() has already updated the | |
1760 | * utilization. We only care of the case where we start to schedule a | |
1761 | * rt task | |
1762 | */ | |
1763 | if (rq->curr->sched_class != &rt_sched_class) | |
1764 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); | |
1765 | ||
1766 | rt_queue_push_tasks(rq); | |
ff1cdc94 MS |
1767 | } |
1768 | ||
821aecd0 | 1769 | static struct sched_rt_entity *pick_next_rt_entity(struct rt_rq *rt_rq) |
bb44e5d1 | 1770 | { |
6f505b16 PZ |
1771 | struct rt_prio_array *array = &rt_rq->active; |
1772 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1773 | struct list_head *queue; |
1774 | int idx; | |
1775 | ||
1776 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1777 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1778 | |
1779 | queue = array->queue + idx; | |
6f505b16 | 1780 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1781 | |
6f505b16 PZ |
1782 | return next; |
1783 | } | |
bb44e5d1 | 1784 | |
917b627d | 1785 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1786 | { |
1787 | struct sched_rt_entity *rt_se; | |
606dba2e | 1788 | struct rt_rq *rt_rq = &rq->rt; |
6f505b16 PZ |
1789 | |
1790 | do { | |
821aecd0 | 1791 | rt_se = pick_next_rt_entity(rt_rq); |
326587b8 | 1792 | BUG_ON(!rt_se); |
6f505b16 PZ |
1793 | rt_rq = group_rt_rq(rt_se); |
1794 | } while (rt_rq); | |
1795 | ||
ff1cdc94 | 1796 | return rt_task_of(rt_se); |
917b627d GH |
1797 | } |
1798 | ||
21f56ffe | 1799 | static struct task_struct *pick_task_rt(struct rq *rq) |
917b627d | 1800 | { |
606dba2e | 1801 | struct task_struct *p; |
606dba2e | 1802 | |
6e2df058 | 1803 | if (!sched_rt_runnable(rq)) |
606dba2e PZ |
1804 | return NULL; |
1805 | ||
606dba2e | 1806 | p = _pick_next_task_rt(rq); |
21f56ffe PZ |
1807 | |
1808 | return p; | |
1809 | } | |
1810 | ||
1811 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
1812 | { | |
1813 | struct task_struct *p = pick_task_rt(rq); | |
1814 | ||
1815 | if (p) | |
1816 | set_next_task_rt(rq, p, true); | |
1817 | ||
6f505b16 | 1818 | return p; |
bb44e5d1 IM |
1819 | } |
1820 | ||
6e2df058 | 1821 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1822 | { |
57a5c2da YS |
1823 | struct sched_rt_entity *rt_se = &p->rt; |
1824 | struct rt_rq *rt_rq = &rq->rt; | |
1825 | ||
1826 | if (on_rt_rq(&p->rt)) | |
1827 | update_stats_wait_start_rt(rt_rq, rt_se); | |
1828 | ||
f1e14ef6 | 1829 | update_curr_rt(rq); |
917b627d | 1830 | |
23127296 | 1831 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); |
371bf427 | 1832 | |
917b627d GH |
1833 | /* |
1834 | * The previous task needs to be made eligible for pushing | |
1835 | * if it is still active | |
1836 | */ | |
4b53a341 | 1837 | if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1) |
917b627d | 1838 | enqueue_pushable_task(rq, p); |
bb44e5d1 IM |
1839 | } |
1840 | ||
681f3e68 | 1841 | #ifdef CONFIG_SMP |
6f505b16 | 1842 | |
e8fa1362 SR |
1843 | /* Only try algorithms three times */ |
1844 | #define RT_MAX_TRIES 3 | |
1845 | ||
f65eda4f SR |
1846 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1847 | { | |
0b9d46fc | 1848 | if (!task_on_cpu(rq, p) && |
95158a89 | 1849 | cpumask_test_cpu(cpu, &p->cpus_mask)) |
f65eda4f | 1850 | return 1; |
97fb7a0a | 1851 | |
f65eda4f SR |
1852 | return 0; |
1853 | } | |
1854 | ||
e23ee747 KT |
1855 | /* |
1856 | * Return the highest pushable rq's task, which is suitable to be executed | |
97fb7a0a | 1857 | * on the CPU, NULL otherwise |
e23ee747 KT |
1858 | */ |
1859 | static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu) | |
e8fa1362 | 1860 | { |
e23ee747 KT |
1861 | struct plist_head *head = &rq->rt.pushable_tasks; |
1862 | struct task_struct *p; | |
3d07467b | 1863 | |
e23ee747 KT |
1864 | if (!has_pushable_tasks(rq)) |
1865 | return NULL; | |
3d07467b | 1866 | |
e23ee747 KT |
1867 | plist_for_each_entry(p, head, pushable_tasks) { |
1868 | if (pick_rt_task(rq, p, cpu)) | |
1869 | return p; | |
f65eda4f SR |
1870 | } |
1871 | ||
e23ee747 | 1872 | return NULL; |
e8fa1362 SR |
1873 | } |
1874 | ||
0e3900e6 | 1875 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1876 | |
6e1254d2 GH |
1877 | static int find_lowest_rq(struct task_struct *task) |
1878 | { | |
1879 | struct sched_domain *sd; | |
4ba29684 | 1880 | struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask); |
6e1254d2 GH |
1881 | int this_cpu = smp_processor_id(); |
1882 | int cpu = task_cpu(task); | |
a1bd02e1 | 1883 | int ret; |
06f90dbd | 1884 | |
0da938c4 SR |
1885 | /* Make sure the mask is initialized first */ |
1886 | if (unlikely(!lowest_mask)) | |
1887 | return -1; | |
1888 | ||
4b53a341 | 1889 | if (task->nr_cpus_allowed == 1) |
6e0534f2 | 1890 | return -1; /* No other targets possible */ |
6e1254d2 | 1891 | |
a1bd02e1 QY |
1892 | /* |
1893 | * If we're on asym system ensure we consider the different capacities | |
1894 | * of the CPUs when searching for the lowest_mask. | |
1895 | */ | |
740cf8a7 | 1896 | if (sched_asym_cpucap_active()) { |
a1bd02e1 QY |
1897 | |
1898 | ret = cpupri_find_fitness(&task_rq(task)->rd->cpupri, | |
1899 | task, lowest_mask, | |
1900 | rt_task_fits_capacity); | |
1901 | } else { | |
1902 | ||
1903 | ret = cpupri_find(&task_rq(task)->rd->cpupri, | |
1904 | task, lowest_mask); | |
1905 | } | |
1906 | ||
1907 | if (!ret) | |
6e0534f2 | 1908 | return -1; /* No targets found */ |
6e1254d2 GH |
1909 | |
1910 | /* | |
97fb7a0a | 1911 | * At this point we have built a mask of CPUs representing the |
6e1254d2 GH |
1912 | * lowest priority tasks in the system. Now we want to elect |
1913 | * the best one based on our affinity and topology. | |
1914 | * | |
97fb7a0a | 1915 | * We prioritize the last CPU that the task executed on since |
6e1254d2 GH |
1916 | * it is most likely cache-hot in that location. |
1917 | */ | |
96f874e2 | 1918 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1919 | return cpu; |
1920 | ||
1921 | /* | |
1922 | * Otherwise, we consult the sched_domains span maps to figure | |
97fb7a0a | 1923 | * out which CPU is logically closest to our hot cache data. |
6e1254d2 | 1924 | */ |
e2c88063 RR |
1925 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) |
1926 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
6e1254d2 | 1927 | |
cd4ae6ad | 1928 | rcu_read_lock(); |
e2c88063 RR |
1929 | for_each_domain(cpu, sd) { |
1930 | if (sd->flags & SD_WAKE_AFFINE) { | |
1931 | int best_cpu; | |
6e1254d2 | 1932 | |
e2c88063 RR |
1933 | /* |
1934 | * "this_cpu" is cheaper to preempt than a | |
1935 | * remote processor. | |
1936 | */ | |
1937 | if (this_cpu != -1 && | |
cd4ae6ad XF |
1938 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { |
1939 | rcu_read_unlock(); | |
e2c88063 | 1940 | return this_cpu; |
cd4ae6ad | 1941 | } |
e2c88063 | 1942 | |
14e292f8 PZ |
1943 | best_cpu = cpumask_any_and_distribute(lowest_mask, |
1944 | sched_domain_span(sd)); | |
cd4ae6ad XF |
1945 | if (best_cpu < nr_cpu_ids) { |
1946 | rcu_read_unlock(); | |
e2c88063 | 1947 | return best_cpu; |
cd4ae6ad | 1948 | } |
6e1254d2 GH |
1949 | } |
1950 | } | |
cd4ae6ad | 1951 | rcu_read_unlock(); |
6e1254d2 GH |
1952 | |
1953 | /* | |
1954 | * And finally, if there were no matches within the domains | |
1955 | * just give the caller *something* to work with from the compatible | |
1956 | * locations. | |
1957 | */ | |
e2c88063 RR |
1958 | if (this_cpu != -1) |
1959 | return this_cpu; | |
1960 | ||
14e292f8 | 1961 | cpu = cpumask_any_distribute(lowest_mask); |
e2c88063 RR |
1962 | if (cpu < nr_cpu_ids) |
1963 | return cpu; | |
97fb7a0a | 1964 | |
e2c88063 | 1965 | return -1; |
07b4032c GH |
1966 | } |
1967 | ||
1968 | /* Will lock the rq it finds */ | |
4df64c0b | 1969 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1970 | { |
1971 | struct rq *lowest_rq = NULL; | |
07b4032c | 1972 | int tries; |
4df64c0b | 1973 | int cpu; |
e8fa1362 | 1974 | |
07b4032c GH |
1975 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1976 | cpu = find_lowest_rq(task); | |
1977 | ||
2de0b463 | 1978 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1979 | break; |
1980 | ||
07b4032c GH |
1981 | lowest_rq = cpu_rq(cpu); |
1982 | ||
80e3d87b TC |
1983 | if (lowest_rq->rt.highest_prio.curr <= task->prio) { |
1984 | /* | |
1985 | * Target rq has tasks of equal or higher priority, | |
1986 | * retrying does not release any lock and is unlikely | |
1987 | * to yield a different result. | |
1988 | */ | |
1989 | lowest_rq = NULL; | |
1990 | break; | |
1991 | } | |
1992 | ||
e8fa1362 | 1993 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1994 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1995 | /* |
1996 | * We had to unlock the run queue. In | |
1997 | * the mean time, task could have | |
1998 | * migrated already or had its affinity changed. | |
1999 | * Also make sure that it wasn't scheduled on its rq. | |
2000 | */ | |
07b4032c | 2001 | if (unlikely(task_rq(task) != rq || |
95158a89 | 2002 | !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_mask) || |
0b9d46fc | 2003 | task_on_cpu(rq, task) || |
13b5ab02 | 2004 | !rt_task(task) || |
da0c1e65 | 2005 | !task_on_rq_queued(task))) { |
4df64c0b | 2006 | |
7f1b4393 | 2007 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
2008 | lowest_rq = NULL; |
2009 | break; | |
2010 | } | |
2011 | } | |
2012 | ||
2013 | /* If this rq is still suitable use it. */ | |
e864c499 | 2014 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
2015 | break; |
2016 | ||
2017 | /* try again */ | |
1b12bbc7 | 2018 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
2019 | lowest_rq = NULL; |
2020 | } | |
2021 | ||
2022 | return lowest_rq; | |
2023 | } | |
2024 | ||
917b627d GH |
2025 | static struct task_struct *pick_next_pushable_task(struct rq *rq) |
2026 | { | |
2027 | struct task_struct *p; | |
2028 | ||
2029 | if (!has_pushable_tasks(rq)) | |
2030 | return NULL; | |
2031 | ||
2032 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
2033 | struct task_struct, pushable_tasks); | |
2034 | ||
2035 | BUG_ON(rq->cpu != task_cpu(p)); | |
2036 | BUG_ON(task_current(rq, p)); | |
4b53a341 | 2037 | BUG_ON(p->nr_cpus_allowed <= 1); |
917b627d | 2038 | |
da0c1e65 | 2039 | BUG_ON(!task_on_rq_queued(p)); |
917b627d GH |
2040 | BUG_ON(!rt_task(p)); |
2041 | ||
2042 | return p; | |
2043 | } | |
2044 | ||
e8fa1362 SR |
2045 | /* |
2046 | * If the current CPU has more than one RT task, see if the non | |
2047 | * running task can migrate over to a CPU that is running a task | |
2048 | * of lesser priority. | |
2049 | */ | |
a7c81556 | 2050 | static int push_rt_task(struct rq *rq, bool pull) |
e8fa1362 SR |
2051 | { |
2052 | struct task_struct *next_task; | |
2053 | struct rq *lowest_rq; | |
311e800e | 2054 | int ret = 0; |
e8fa1362 | 2055 | |
a22d7fc1 GH |
2056 | if (!rq->rt.overloaded) |
2057 | return 0; | |
2058 | ||
917b627d | 2059 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
2060 | if (!next_task) |
2061 | return 0; | |
2062 | ||
49246274 | 2063 | retry: |
49bef33e VS |
2064 | /* |
2065 | * It's possible that the next_task slipped in of | |
2066 | * higher priority than current. If that's the case | |
2067 | * just reschedule current. | |
2068 | */ | |
2069 | if (unlikely(next_task->prio < rq->curr->prio)) { | |
2070 | resched_curr(rq); | |
2071 | return 0; | |
2072 | } | |
2073 | ||
a7c81556 PZ |
2074 | if (is_migration_disabled(next_task)) { |
2075 | struct task_struct *push_task = NULL; | |
2076 | int cpu; | |
2077 | ||
2078 | if (!pull || rq->push_busy) | |
2079 | return 0; | |
2080 | ||
49bef33e VS |
2081 | /* |
2082 | * Invoking find_lowest_rq() on anything but an RT task doesn't | |
2083 | * make sense. Per the above priority check, curr has to | |
2084 | * be of higher priority than next_task, so no need to | |
2085 | * reschedule when bailing out. | |
2086 | * | |
2087 | * Note that the stoppers are masqueraded as SCHED_FIFO | |
2088 | * (cf. sched_set_stop_task()), so we can't rely on rt_task(). | |
2089 | */ | |
2090 | if (rq->curr->sched_class != &rt_sched_class) | |
2091 | return 0; | |
2092 | ||
a7c81556 PZ |
2093 | cpu = find_lowest_rq(rq->curr); |
2094 | if (cpu == -1 || cpu == rq->cpu) | |
2095 | return 0; | |
2096 | ||
2097 | /* | |
2098 | * Given we found a CPU with lower priority than @next_task, | |
2099 | * therefore it should be running. However we cannot migrate it | |
2100 | * to this other CPU, instead attempt to push the current | |
2101 | * running task on this CPU away. | |
2102 | */ | |
2103 | push_task = get_push_task(rq); | |
2104 | if (push_task) { | |
5cb9eaa3 | 2105 | raw_spin_rq_unlock(rq); |
a7c81556 PZ |
2106 | stop_one_cpu_nowait(rq->cpu, push_cpu_stop, |
2107 | push_task, &rq->push_work); | |
5cb9eaa3 | 2108 | raw_spin_rq_lock(rq); |
a7c81556 PZ |
2109 | } |
2110 | ||
2111 | return 0; | |
2112 | } | |
2113 | ||
9ebc6053 | 2114 | if (WARN_ON(next_task == rq->curr)) |
e8fa1362 SR |
2115 | return 0; |
2116 | ||
697f0a48 | 2117 | /* We might release rq lock */ |
e8fa1362 SR |
2118 | get_task_struct(next_task); |
2119 | ||
2120 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 2121 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
2122 | if (!lowest_rq) { |
2123 | struct task_struct *task; | |
2124 | /* | |
311e800e | 2125 | * find_lock_lowest_rq releases rq->lock |
1563513d GH |
2126 | * so it is possible that next_task has migrated. |
2127 | * | |
2128 | * We need to make sure that the task is still on the same | |
2129 | * run-queue and is also still the next task eligible for | |
2130 | * pushing. | |
e8fa1362 | 2131 | */ |
917b627d | 2132 | task = pick_next_pushable_task(rq); |
de16b91e | 2133 | if (task == next_task) { |
1563513d | 2134 | /* |
311e800e HD |
2135 | * The task hasn't migrated, and is still the next |
2136 | * eligible task, but we failed to find a run-queue | |
2137 | * to push it to. Do not retry in this case, since | |
97fb7a0a | 2138 | * other CPUs will pull from us when ready. |
1563513d | 2139 | */ |
1563513d | 2140 | goto out; |
e8fa1362 | 2141 | } |
917b627d | 2142 | |
1563513d GH |
2143 | if (!task) |
2144 | /* No more tasks, just exit */ | |
2145 | goto out; | |
2146 | ||
917b627d | 2147 | /* |
1563513d | 2148 | * Something has shifted, try again. |
917b627d | 2149 | */ |
1563513d GH |
2150 | put_task_struct(next_task); |
2151 | next_task = task; | |
2152 | goto retry; | |
e8fa1362 SR |
2153 | } |
2154 | ||
697f0a48 | 2155 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
2156 | set_task_cpu(next_task, lowest_rq->cpu); |
2157 | activate_task(lowest_rq, next_task, 0); | |
8875125e | 2158 | resched_curr(lowest_rq); |
a7c81556 | 2159 | ret = 1; |
e8fa1362 | 2160 | |
1b12bbc7 | 2161 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
2162 | out: |
2163 | put_task_struct(next_task); | |
2164 | ||
311e800e | 2165 | return ret; |
e8fa1362 SR |
2166 | } |
2167 | ||
e8fa1362 SR |
2168 | static void push_rt_tasks(struct rq *rq) |
2169 | { | |
2170 | /* push_rt_task will return true if it moved an RT */ | |
a7c81556 | 2171 | while (push_rt_task(rq, false)) |
e8fa1362 SR |
2172 | ; |
2173 | } | |
2174 | ||
b6366f04 | 2175 | #ifdef HAVE_RT_PUSH_IPI |
4bdced5c | 2176 | |
b6366f04 | 2177 | /* |
4bdced5c SRRH |
2178 | * When a high priority task schedules out from a CPU and a lower priority |
2179 | * task is scheduled in, a check is made to see if there's any RT tasks | |
2180 | * on other CPUs that are waiting to run because a higher priority RT task | |
2181 | * is currently running on its CPU. In this case, the CPU with multiple RT | |
2182 | * tasks queued on it (overloaded) needs to be notified that a CPU has opened | |
2183 | * up that may be able to run one of its non-running queued RT tasks. | |
2184 | * | |
2185 | * All CPUs with overloaded RT tasks need to be notified as there is currently | |
2186 | * no way to know which of these CPUs have the highest priority task waiting | |
2187 | * to run. Instead of trying to take a spinlock on each of these CPUs, | |
2188 | * which has shown to cause large latency when done on machines with many | |
2189 | * CPUs, sending an IPI to the CPUs to have them push off the overloaded | |
2190 | * RT tasks waiting to run. | |
2191 | * | |
2192 | * Just sending an IPI to each of the CPUs is also an issue, as on large | |
2193 | * count CPU machines, this can cause an IPI storm on a CPU, especially | |
2194 | * if its the only CPU with multiple RT tasks queued, and a large number | |
2195 | * of CPUs scheduling a lower priority task at the same time. | |
2196 | * | |
2197 | * Each root domain has its own irq work function that can iterate over | |
2198 | * all CPUs with RT overloaded tasks. Since all CPUs with overloaded RT | |
3b03706f | 2199 | * task must be checked if there's one or many CPUs that are lowering |
4bdced5c SRRH |
2200 | * their priority, there's a single irq work iterator that will try to |
2201 | * push off RT tasks that are waiting to run. | |
2202 | * | |
2203 | * When a CPU schedules a lower priority task, it will kick off the | |
2204 | * irq work iterator that will jump to each CPU with overloaded RT tasks. | |
2205 | * As it only takes the first CPU that schedules a lower priority task | |
2206 | * to start the process, the rto_start variable is incremented and if | |
2207 | * the atomic result is one, then that CPU will try to take the rto_lock. | |
2208 | * This prevents high contention on the lock as the process handles all | |
2209 | * CPUs scheduling lower priority tasks. | |
2210 | * | |
2211 | * All CPUs that are scheduling a lower priority task will increment the | |
2212 | * rt_loop_next variable. This will make sure that the irq work iterator | |
2213 | * checks all RT overloaded CPUs whenever a CPU schedules a new lower | |
2214 | * priority task, even if the iterator is in the middle of a scan. Incrementing | |
2215 | * the rt_loop_next will cause the iterator to perform another scan. | |
b6366f04 | 2216 | * |
b6366f04 | 2217 | */ |
ad0f1d9d | 2218 | static int rto_next_cpu(struct root_domain *rd) |
b6366f04 | 2219 | { |
4bdced5c | 2220 | int next; |
b6366f04 SR |
2221 | int cpu; |
2222 | ||
b6366f04 | 2223 | /* |
4bdced5c SRRH |
2224 | * When starting the IPI RT pushing, the rto_cpu is set to -1, |
2225 | * rt_next_cpu() will simply return the first CPU found in | |
2226 | * the rto_mask. | |
2227 | * | |
97fb7a0a | 2228 | * If rto_next_cpu() is called with rto_cpu is a valid CPU, it |
4bdced5c SRRH |
2229 | * will return the next CPU found in the rto_mask. |
2230 | * | |
2231 | * If there are no more CPUs left in the rto_mask, then a check is made | |
2232 | * against rto_loop and rto_loop_next. rto_loop is only updated with | |
2233 | * the rto_lock held, but any CPU may increment the rto_loop_next | |
2234 | * without any locking. | |
b6366f04 | 2235 | */ |
4bdced5c | 2236 | for (;;) { |
b6366f04 | 2237 | |
4bdced5c SRRH |
2238 | /* When rto_cpu is -1 this acts like cpumask_first() */ |
2239 | cpu = cpumask_next(rd->rto_cpu, rd->rto_mask); | |
b6366f04 | 2240 | |
4bdced5c | 2241 | rd->rto_cpu = cpu; |
b6366f04 | 2242 | |
4bdced5c SRRH |
2243 | if (cpu < nr_cpu_ids) |
2244 | return cpu; | |
b6366f04 | 2245 | |
4bdced5c SRRH |
2246 | rd->rto_cpu = -1; |
2247 | ||
2248 | /* | |
2249 | * ACQUIRE ensures we see the @rto_mask changes | |
2250 | * made prior to the @next value observed. | |
2251 | * | |
2252 | * Matches WMB in rt_set_overload(). | |
2253 | */ | |
2254 | next = atomic_read_acquire(&rd->rto_loop_next); | |
b6366f04 | 2255 | |
4bdced5c | 2256 | if (rd->rto_loop == next) |
b6366f04 | 2257 | break; |
4bdced5c SRRH |
2258 | |
2259 | rd->rto_loop = next; | |
b6366f04 SR |
2260 | } |
2261 | ||
4bdced5c | 2262 | return -1; |
b6366f04 SR |
2263 | } |
2264 | ||
4bdced5c SRRH |
2265 | static inline bool rto_start_trylock(atomic_t *v) |
2266 | { | |
2267 | return !atomic_cmpxchg_acquire(v, 0, 1); | |
2268 | } | |
b6366f04 | 2269 | |
4bdced5c | 2270 | static inline void rto_start_unlock(atomic_t *v) |
b6366f04 | 2271 | { |
4bdced5c SRRH |
2272 | atomic_set_release(v, 0); |
2273 | } | |
b6366f04 | 2274 | |
4bdced5c SRRH |
2275 | static void tell_cpu_to_push(struct rq *rq) |
2276 | { | |
2277 | int cpu = -1; | |
b6366f04 | 2278 | |
4bdced5c SRRH |
2279 | /* Keep the loop going if the IPI is currently active */ |
2280 | atomic_inc(&rq->rd->rto_loop_next); | |
b6366f04 | 2281 | |
4bdced5c SRRH |
2282 | /* Only one CPU can initiate a loop at a time */ |
2283 | if (!rto_start_trylock(&rq->rd->rto_loop_start)) | |
b6366f04 SR |
2284 | return; |
2285 | ||
4bdced5c | 2286 | raw_spin_lock(&rq->rd->rto_lock); |
b6366f04 | 2287 | |
4bdced5c | 2288 | /* |
97fb7a0a | 2289 | * The rto_cpu is updated under the lock, if it has a valid CPU |
4bdced5c SRRH |
2290 | * then the IPI is still running and will continue due to the |
2291 | * update to loop_next, and nothing needs to be done here. | |
2292 | * Otherwise it is finishing up and an ipi needs to be sent. | |
2293 | */ | |
2294 | if (rq->rd->rto_cpu < 0) | |
ad0f1d9d | 2295 | cpu = rto_next_cpu(rq->rd); |
4bdced5c SRRH |
2296 | |
2297 | raw_spin_unlock(&rq->rd->rto_lock); | |
2298 | ||
2299 | rto_start_unlock(&rq->rd->rto_loop_start); | |
2300 | ||
364f5665 SRV |
2301 | if (cpu >= 0) { |
2302 | /* Make sure the rd does not get freed while pushing */ | |
2303 | sched_get_rd(rq->rd); | |
4bdced5c | 2304 | irq_work_queue_on(&rq->rd->rto_push_work, cpu); |
364f5665 | 2305 | } |
b6366f04 SR |
2306 | } |
2307 | ||
2308 | /* Called from hardirq context */ | |
4bdced5c | 2309 | void rto_push_irq_work_func(struct irq_work *work) |
b6366f04 | 2310 | { |
ad0f1d9d SRV |
2311 | struct root_domain *rd = |
2312 | container_of(work, struct root_domain, rto_push_work); | |
4bdced5c | 2313 | struct rq *rq; |
b6366f04 SR |
2314 | int cpu; |
2315 | ||
4bdced5c | 2316 | rq = this_rq(); |
b6366f04 | 2317 | |
4bdced5c SRRH |
2318 | /* |
2319 | * We do not need to grab the lock to check for has_pushable_tasks. | |
2320 | * When it gets updated, a check is made if a push is possible. | |
2321 | */ | |
b6366f04 | 2322 | if (has_pushable_tasks(rq)) { |
5cb9eaa3 | 2323 | raw_spin_rq_lock(rq); |
a7c81556 PZ |
2324 | while (push_rt_task(rq, true)) |
2325 | ; | |
5cb9eaa3 | 2326 | raw_spin_rq_unlock(rq); |
b6366f04 SR |
2327 | } |
2328 | ||
ad0f1d9d | 2329 | raw_spin_lock(&rd->rto_lock); |
b6366f04 | 2330 | |
4bdced5c | 2331 | /* Pass the IPI to the next rt overloaded queue */ |
ad0f1d9d | 2332 | cpu = rto_next_cpu(rd); |
b6366f04 | 2333 | |
ad0f1d9d | 2334 | raw_spin_unlock(&rd->rto_lock); |
b6366f04 | 2335 | |
364f5665 SRV |
2336 | if (cpu < 0) { |
2337 | sched_put_rd(rd); | |
b6366f04 | 2338 | return; |
364f5665 | 2339 | } |
b6366f04 | 2340 | |
b6366f04 | 2341 | /* Try the next RT overloaded CPU */ |
ad0f1d9d | 2342 | irq_work_queue_on(&rd->rto_push_work, cpu); |
b6366f04 SR |
2343 | } |
2344 | #endif /* HAVE_RT_PUSH_IPI */ | |
2345 | ||
8046d680 | 2346 | static void pull_rt_task(struct rq *this_rq) |
f65eda4f | 2347 | { |
8046d680 PZ |
2348 | int this_cpu = this_rq->cpu, cpu; |
2349 | bool resched = false; | |
a7c81556 | 2350 | struct task_struct *p, *push_task; |
f65eda4f | 2351 | struct rq *src_rq; |
f73c52a5 | 2352 | int rt_overload_count = rt_overloaded(this_rq); |
f65eda4f | 2353 | |
f73c52a5 | 2354 | if (likely(!rt_overload_count)) |
8046d680 | 2355 | return; |
f65eda4f | 2356 | |
7c3f2ab7 PZ |
2357 | /* |
2358 | * Match the barrier from rt_set_overloaded; this guarantees that if we | |
2359 | * see overloaded we must also see the rto_mask bit. | |
2360 | */ | |
2361 | smp_rmb(); | |
2362 | ||
f73c52a5 SR |
2363 | /* If we are the only overloaded CPU do nothing */ |
2364 | if (rt_overload_count == 1 && | |
2365 | cpumask_test_cpu(this_rq->cpu, this_rq->rd->rto_mask)) | |
2366 | return; | |
2367 | ||
b6366f04 SR |
2368 | #ifdef HAVE_RT_PUSH_IPI |
2369 | if (sched_feat(RT_PUSH_IPI)) { | |
2370 | tell_cpu_to_push(this_rq); | |
8046d680 | 2371 | return; |
b6366f04 SR |
2372 | } |
2373 | #endif | |
2374 | ||
c6c4927b | 2375 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
2376 | if (this_cpu == cpu) |
2377 | continue; | |
2378 | ||
2379 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
2380 | |
2381 | /* | |
2382 | * Don't bother taking the src_rq->lock if the next highest | |
2383 | * task is known to be lower-priority than our current task. | |
2384 | * This may look racy, but if this value is about to go | |
2385 | * logically higher, the src_rq will push this task away. | |
2386 | * And if its going logically lower, we do not care | |
2387 | */ | |
2388 | if (src_rq->rt.highest_prio.next >= | |
2389 | this_rq->rt.highest_prio.curr) | |
2390 | continue; | |
2391 | ||
f65eda4f SR |
2392 | /* |
2393 | * We can potentially drop this_rq's lock in | |
2394 | * double_lock_balance, and another CPU could | |
a8728944 | 2395 | * alter this_rq |
f65eda4f | 2396 | */ |
a7c81556 | 2397 | push_task = NULL; |
a8728944 | 2398 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
2399 | |
2400 | /* | |
e23ee747 KT |
2401 | * We can pull only a task, which is pushable |
2402 | * on its rq, and no others. | |
f65eda4f | 2403 | */ |
e23ee747 | 2404 | p = pick_highest_pushable_task(src_rq, this_cpu); |
f65eda4f SR |
2405 | |
2406 | /* | |
2407 | * Do we have an RT task that preempts | |
2408 | * the to-be-scheduled task? | |
2409 | */ | |
a8728944 | 2410 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f | 2411 | WARN_ON(p == src_rq->curr); |
da0c1e65 | 2412 | WARN_ON(!task_on_rq_queued(p)); |
f65eda4f SR |
2413 | |
2414 | /* | |
2415 | * There's a chance that p is higher in priority | |
97fb7a0a | 2416 | * than what's currently running on its CPU. |
3b03706f | 2417 | * This is just that p is waking up and hasn't |
f65eda4f SR |
2418 | * had a chance to schedule. We only pull |
2419 | * p if it is lower in priority than the | |
a8728944 | 2420 | * current task on the run queue |
f65eda4f | 2421 | */ |
a8728944 | 2422 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 2423 | goto skip; |
f65eda4f | 2424 | |
a7c81556 PZ |
2425 | if (is_migration_disabled(p)) { |
2426 | push_task = get_push_task(src_rq); | |
2427 | } else { | |
2428 | deactivate_task(src_rq, p, 0); | |
2429 | set_task_cpu(p, this_cpu); | |
2430 | activate_task(this_rq, p, 0); | |
2431 | resched = true; | |
2432 | } | |
f65eda4f SR |
2433 | /* |
2434 | * We continue with the search, just in | |
2435 | * case there's an even higher prio task | |
25985edc | 2436 | * in another runqueue. (low likelihood |
f65eda4f | 2437 | * but possible) |
f65eda4f | 2438 | */ |
f65eda4f | 2439 | } |
49246274 | 2440 | skip: |
1b12bbc7 | 2441 | double_unlock_balance(this_rq, src_rq); |
a7c81556 PZ |
2442 | |
2443 | if (push_task) { | |
5cb9eaa3 | 2444 | raw_spin_rq_unlock(this_rq); |
a7c81556 PZ |
2445 | stop_one_cpu_nowait(src_rq->cpu, push_cpu_stop, |
2446 | push_task, &src_rq->push_work); | |
5cb9eaa3 | 2447 | raw_spin_rq_lock(this_rq); |
a7c81556 | 2448 | } |
f65eda4f SR |
2449 | } |
2450 | ||
8046d680 PZ |
2451 | if (resched) |
2452 | resched_curr(this_rq); | |
f65eda4f SR |
2453 | } |
2454 | ||
8ae121ac GH |
2455 | /* |
2456 | * If we are not running and we are not going to reschedule soon, we should | |
2457 | * try to push tasks away now | |
2458 | */ | |
efbbd05a | 2459 | static void task_woken_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 2460 | { |
0b9d46fc | 2461 | bool need_to_push = !task_on_cpu(rq, p) && |
804d402f QY |
2462 | !test_tsk_need_resched(rq->curr) && |
2463 | p->nr_cpus_allowed > 1 && | |
2464 | (dl_task(rq->curr) || rt_task(rq->curr)) && | |
2465 | (rq->curr->nr_cpus_allowed < 2 || | |
2466 | rq->curr->prio <= p->prio); | |
2467 | ||
d94a9df4 | 2468 | if (need_to_push) |
4642dafd SR |
2469 | push_rt_tasks(rq); |
2470 | } | |
2471 | ||
bdd7c81b | 2472 | /* Assumes rq->lock is held */ |
1f11eb6a | 2473 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
2474 | { |
2475 | if (rq->rt.overloaded) | |
2476 | rt_set_overload(rq); | |
6e0534f2 | 2477 | |
7def2be1 PZ |
2478 | __enable_runtime(rq); |
2479 | ||
e864c499 | 2480 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
2481 | } |
2482 | ||
2483 | /* Assumes rq->lock is held */ | |
1f11eb6a | 2484 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
2485 | { |
2486 | if (rq->rt.overloaded) | |
2487 | rt_clear_overload(rq); | |
6e0534f2 | 2488 | |
7def2be1 PZ |
2489 | __disable_runtime(rq); |
2490 | ||
6e0534f2 | 2491 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 2492 | } |
cb469845 SR |
2493 | |
2494 | /* | |
2495 | * When switch from the rt queue, we bring ourselves to a position | |
2496 | * that we might want to pull RT tasks from other runqueues. | |
2497 | */ | |
da7a735e | 2498 | static void switched_from_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
2499 | { |
2500 | /* | |
2501 | * If there are other RT tasks then we will reschedule | |
2502 | * and the scheduling of the other RT tasks will handle | |
2503 | * the balancing. But if we are the last RT task | |
2504 | * we may need to handle the pulling of RT tasks | |
2505 | * now. | |
2506 | */ | |
da0c1e65 | 2507 | if (!task_on_rq_queued(p) || rq->rt.rt_nr_running) |
1158ddb5 KT |
2508 | return; |
2509 | ||
02d8ec94 | 2510 | rt_queue_pull_task(rq); |
cb469845 | 2511 | } |
3d8cbdf8 | 2512 | |
11c785b7 | 2513 | void __init init_sched_rt_class(void) |
3d8cbdf8 RR |
2514 | { |
2515 | unsigned int i; | |
2516 | ||
029632fb | 2517 | for_each_possible_cpu(i) { |
eaa95840 | 2518 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
6ca09dfc | 2519 | GFP_KERNEL, cpu_to_node(i)); |
029632fb | 2520 | } |
3d8cbdf8 | 2521 | } |
cb469845 SR |
2522 | #endif /* CONFIG_SMP */ |
2523 | ||
2524 | /* | |
2525 | * When switching a task to RT, we may overload the runqueue | |
2526 | * with RT tasks. In this case we try to push them off to | |
2527 | * other runqueues. | |
2528 | */ | |
da7a735e | 2529 | static void switched_to_rt(struct rq *rq, struct task_struct *p) |
cb469845 | 2530 | { |
cb469845 | 2531 | /* |
fecfcbc2 VD |
2532 | * If we are running, update the avg_rt tracking, as the running time |
2533 | * will now on be accounted into the latter. | |
2534 | */ | |
2535 | if (task_current(rq, p)) { | |
2536 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); | |
2537 | return; | |
2538 | } | |
2539 | ||
2540 | /* | |
2541 | * If we are not running we may need to preempt the current | |
2542 | * running task. If that current running task is also an RT task | |
cb469845 SR |
2543 | * then see if we can move to another run queue. |
2544 | */ | |
fecfcbc2 | 2545 | if (task_on_rq_queued(p)) { |
cb469845 | 2546 | #ifdef CONFIG_SMP |
d94a9df4 | 2547 | if (p->nr_cpus_allowed > 1 && rq->rt.overloaded) |
02d8ec94 | 2548 | rt_queue_push_tasks(rq); |
619bd4a7 | 2549 | #endif /* CONFIG_SMP */ |
2fe25826 | 2550 | if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq))) |
8875125e | 2551 | resched_curr(rq); |
cb469845 SR |
2552 | } |
2553 | } | |
2554 | ||
2555 | /* | |
2556 | * Priority of the task has changed. This may cause | |
2557 | * us to initiate a push or pull. | |
2558 | */ | |
da7a735e PZ |
2559 | static void |
2560 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 2561 | { |
da0c1e65 | 2562 | if (!task_on_rq_queued(p)) |
da7a735e PZ |
2563 | return; |
2564 | ||
65bcf072 | 2565 | if (task_current(rq, p)) { |
cb469845 SR |
2566 | #ifdef CONFIG_SMP |
2567 | /* | |
2568 | * If our priority decreases while running, we | |
2569 | * may need to pull tasks to this runqueue. | |
2570 | */ | |
2571 | if (oldprio < p->prio) | |
02d8ec94 | 2572 | rt_queue_pull_task(rq); |
fd7a4bed | 2573 | |
cb469845 SR |
2574 | /* |
2575 | * If there's a higher priority task waiting to run | |
fd7a4bed | 2576 | * then reschedule. |
cb469845 | 2577 | */ |
fd7a4bed | 2578 | if (p->prio > rq->rt.highest_prio.curr) |
8875125e | 2579 | resched_curr(rq); |
cb469845 SR |
2580 | #else |
2581 | /* For UP simply resched on drop of prio */ | |
2582 | if (oldprio < p->prio) | |
8875125e | 2583 | resched_curr(rq); |
e8fa1362 | 2584 | #endif /* CONFIG_SMP */ |
cb469845 SR |
2585 | } else { |
2586 | /* | |
2587 | * This task is not running, but if it is | |
2588 | * greater than the current running task | |
2589 | * then reschedule. | |
2590 | */ | |
2591 | if (p->prio < rq->curr->prio) | |
8875125e | 2592 | resched_curr(rq); |
cb469845 SR |
2593 | } |
2594 | } | |
2595 | ||
b18b6a9c | 2596 | #ifdef CONFIG_POSIX_TIMERS |
78f2c7db PZ |
2597 | static void watchdog(struct rq *rq, struct task_struct *p) |
2598 | { | |
2599 | unsigned long soft, hard; | |
2600 | ||
78d7d407 JS |
2601 | /* max may change after cur was read, this will be fixed next tick */ |
2602 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
2603 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
78f2c7db PZ |
2604 | |
2605 | if (soft != RLIM_INFINITY) { | |
2606 | unsigned long next; | |
2607 | ||
57d2aa00 YX |
2608 | if (p->rt.watchdog_stamp != jiffies) { |
2609 | p->rt.timeout++; | |
2610 | p->rt.watchdog_stamp = jiffies; | |
2611 | } | |
2612 | ||
78f2c7db | 2613 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); |
3a245c0f TG |
2614 | if (p->rt.timeout > next) { |
2615 | posix_cputimers_rt_watchdog(&p->posix_cputimers, | |
2616 | p->se.sum_exec_runtime); | |
2617 | } | |
78f2c7db PZ |
2618 | } |
2619 | } | |
b18b6a9c NP |
2620 | #else |
2621 | static inline void watchdog(struct rq *rq, struct task_struct *p) { } | |
2622 | #endif | |
bb44e5d1 | 2623 | |
d84b3131 FW |
2624 | /* |
2625 | * scheduler tick hitting a task of our scheduling class. | |
2626 | * | |
2627 | * NOTE: This function can be called remotely by the tick offload that | |
2628 | * goes along full dynticks. Therefore no local assumption can be made | |
2629 | * and everything must be accessed through the @rq and @curr passed in | |
2630 | * parameters. | |
2631 | */ | |
8f4d37ec | 2632 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 2633 | { |
454c7999 CC |
2634 | struct sched_rt_entity *rt_se = &p->rt; |
2635 | ||
67e2be02 | 2636 | update_curr_rt(rq); |
23127296 | 2637 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); |
67e2be02 | 2638 | |
78f2c7db PZ |
2639 | watchdog(rq, p); |
2640 | ||
bb44e5d1 IM |
2641 | /* |
2642 | * RR tasks need a special form of timeslice management. | |
2643 | * FIFO tasks have no timeslices. | |
2644 | */ | |
2645 | if (p->policy != SCHED_RR) | |
2646 | return; | |
2647 | ||
fa717060 | 2648 | if (--p->rt.time_slice) |
bb44e5d1 IM |
2649 | return; |
2650 | ||
ce0dbbbb | 2651 | p->rt.time_slice = sched_rr_timeslice; |
bb44e5d1 | 2652 | |
98fbc798 | 2653 | /* |
e9aa39bb LB |
2654 | * Requeue to the end of queue if we (and all of our ancestors) are not |
2655 | * the only element on the queue | |
98fbc798 | 2656 | */ |
454c7999 CC |
2657 | for_each_sched_rt_entity(rt_se) { |
2658 | if (rt_se->run_list.prev != rt_se->run_list.next) { | |
2659 | requeue_task_rt(rq, p, 0); | |
8aa6f0eb | 2660 | resched_curr(rq); |
454c7999 CC |
2661 | return; |
2662 | } | |
98fbc798 | 2663 | } |
bb44e5d1 IM |
2664 | } |
2665 | ||
6d686f45 | 2666 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) |
0d721cea PW |
2667 | { |
2668 | /* | |
2669 | * Time slice is 0 for SCHED_FIFO tasks | |
2670 | */ | |
2671 | if (task->policy == SCHED_RR) | |
ce0dbbbb | 2672 | return sched_rr_timeslice; |
0d721cea PW |
2673 | else |
2674 | return 0; | |
2675 | } | |
2676 | ||
43c31ac0 PZ |
2677 | DEFINE_SCHED_CLASS(rt) = { |
2678 | ||
bb44e5d1 IM |
2679 | .enqueue_task = enqueue_task_rt, |
2680 | .dequeue_task = dequeue_task_rt, | |
2681 | .yield_task = yield_task_rt, | |
2682 | ||
2683 | .check_preempt_curr = check_preempt_curr_rt, | |
2684 | ||
2685 | .pick_next_task = pick_next_task_rt, | |
2686 | .put_prev_task = put_prev_task_rt, | |
03b7fad1 | 2687 | .set_next_task = set_next_task_rt, |
bb44e5d1 | 2688 | |
681f3e68 | 2689 | #ifdef CONFIG_SMP |
6e2df058 | 2690 | .balance = balance_rt, |
21f56ffe | 2691 | .pick_task = pick_task_rt, |
4ce72a2c | 2692 | .select_task_rq = select_task_rq_rt, |
6c37067e | 2693 | .set_cpus_allowed = set_cpus_allowed_common, |
1f11eb6a GH |
2694 | .rq_online = rq_online_rt, |
2695 | .rq_offline = rq_offline_rt, | |
efbbd05a | 2696 | .task_woken = task_woken_rt, |
cb469845 | 2697 | .switched_from = switched_from_rt, |
a7c81556 | 2698 | .find_lock_rq = find_lock_lowest_rq, |
681f3e68 | 2699 | #endif |
bb44e5d1 IM |
2700 | |
2701 | .task_tick = task_tick_rt, | |
cb469845 | 2702 | |
0d721cea PW |
2703 | .get_rr_interval = get_rr_interval_rt, |
2704 | ||
cb469845 SR |
2705 | .prio_changed = prio_changed_rt, |
2706 | .switched_to = switched_to_rt, | |
6e998916 SG |
2707 | |
2708 | .update_curr = update_curr_rt, | |
982d9cdc PB |
2709 | |
2710 | #ifdef CONFIG_UCLAMP_TASK | |
2711 | .uclamp_enabled = 1, | |
2712 | #endif | |
bb44e5d1 | 2713 | }; |
ada18de2 | 2714 | |
8887cd99 NP |
2715 | #ifdef CONFIG_RT_GROUP_SCHED |
2716 | /* | |
2717 | * Ensure that the real time constraints are schedulable. | |
2718 | */ | |
2719 | static DEFINE_MUTEX(rt_constraints_mutex); | |
2720 | ||
8887cd99 NP |
2721 | static inline int tg_has_rt_tasks(struct task_group *tg) |
2722 | { | |
b4fb015e KK |
2723 | struct task_struct *task; |
2724 | struct css_task_iter it; | |
2725 | int ret = 0; | |
8887cd99 NP |
2726 | |
2727 | /* | |
2728 | * Autogroups do not have RT tasks; see autogroup_create(). | |
2729 | */ | |
2730 | if (task_group_is_autogroup(tg)) | |
2731 | return 0; | |
2732 | ||
b4fb015e KK |
2733 | css_task_iter_start(&tg->css, 0, &it); |
2734 | while (!ret && (task = css_task_iter_next(&it))) | |
2735 | ret |= rt_task(task); | |
2736 | css_task_iter_end(&it); | |
8887cd99 | 2737 | |
b4fb015e | 2738 | return ret; |
8887cd99 NP |
2739 | } |
2740 | ||
2741 | struct rt_schedulable_data { | |
2742 | struct task_group *tg; | |
2743 | u64 rt_period; | |
2744 | u64 rt_runtime; | |
2745 | }; | |
2746 | ||
2747 | static int tg_rt_schedulable(struct task_group *tg, void *data) | |
2748 | { | |
2749 | struct rt_schedulable_data *d = data; | |
2750 | struct task_group *child; | |
2751 | unsigned long total, sum = 0; | |
2752 | u64 period, runtime; | |
2753 | ||
2754 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
2755 | runtime = tg->rt_bandwidth.rt_runtime; | |
2756 | ||
2757 | if (tg == d->tg) { | |
2758 | period = d->rt_period; | |
2759 | runtime = d->rt_runtime; | |
2760 | } | |
2761 | ||
2762 | /* | |
2763 | * Cannot have more runtime than the period. | |
2764 | */ | |
2765 | if (runtime > period && runtime != RUNTIME_INF) | |
2766 | return -EINVAL; | |
2767 | ||
2768 | /* | |
b4fb015e | 2769 | * Ensure we don't starve existing RT tasks if runtime turns zero. |
8887cd99 | 2770 | */ |
b4fb015e KK |
2771 | if (rt_bandwidth_enabled() && !runtime && |
2772 | tg->rt_bandwidth.rt_runtime && tg_has_rt_tasks(tg)) | |
8887cd99 NP |
2773 | return -EBUSY; |
2774 | ||
2775 | total = to_ratio(period, runtime); | |
2776 | ||
2777 | /* | |
2778 | * Nobody can have more than the global setting allows. | |
2779 | */ | |
2780 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
2781 | return -EINVAL; | |
2782 | ||
2783 | /* | |
2784 | * The sum of our children's runtime should not exceed our own. | |
2785 | */ | |
2786 | list_for_each_entry_rcu(child, &tg->children, siblings) { | |
2787 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
2788 | runtime = child->rt_bandwidth.rt_runtime; | |
2789 | ||
2790 | if (child == d->tg) { | |
2791 | period = d->rt_period; | |
2792 | runtime = d->rt_runtime; | |
2793 | } | |
2794 | ||
2795 | sum += to_ratio(period, runtime); | |
2796 | } | |
2797 | ||
2798 | if (sum > total) | |
2799 | return -EINVAL; | |
2800 | ||
2801 | return 0; | |
2802 | } | |
2803 | ||
2804 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) | |
2805 | { | |
2806 | int ret; | |
2807 | ||
2808 | struct rt_schedulable_data data = { | |
2809 | .tg = tg, | |
2810 | .rt_period = period, | |
2811 | .rt_runtime = runtime, | |
2812 | }; | |
2813 | ||
2814 | rcu_read_lock(); | |
2815 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
2816 | rcu_read_unlock(); | |
2817 | ||
2818 | return ret; | |
2819 | } | |
2820 | ||
2821 | static int tg_set_rt_bandwidth(struct task_group *tg, | |
2822 | u64 rt_period, u64 rt_runtime) | |
2823 | { | |
2824 | int i, err = 0; | |
2825 | ||
2826 | /* | |
2827 | * Disallowing the root group RT runtime is BAD, it would disallow the | |
2828 | * kernel creating (and or operating) RT threads. | |
2829 | */ | |
2830 | if (tg == &root_task_group && rt_runtime == 0) | |
2831 | return -EINVAL; | |
2832 | ||
2833 | /* No period doesn't make any sense. */ | |
2834 | if (rt_period == 0) | |
2835 | return -EINVAL; | |
2836 | ||
d505b8af HC |
2837 | /* |
2838 | * Bound quota to defend quota against overflow during bandwidth shift. | |
2839 | */ | |
2840 | if (rt_runtime != RUNTIME_INF && rt_runtime > max_rt_runtime) | |
2841 | return -EINVAL; | |
2842 | ||
8887cd99 | 2843 | mutex_lock(&rt_constraints_mutex); |
8887cd99 NP |
2844 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
2845 | if (err) | |
2846 | goto unlock; | |
2847 | ||
2848 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
2849 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); | |
2850 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
2851 | ||
2852 | for_each_possible_cpu(i) { | |
2853 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
2854 | ||
2855 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
2856 | rt_rq->rt_runtime = rt_runtime; | |
2857 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
2858 | } | |
2859 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
2860 | unlock: | |
8887cd99 NP |
2861 | mutex_unlock(&rt_constraints_mutex); |
2862 | ||
2863 | return err; | |
2864 | } | |
2865 | ||
2866 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) | |
2867 | { | |
2868 | u64 rt_runtime, rt_period; | |
2869 | ||
2870 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
2871 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
2872 | if (rt_runtime_us < 0) | |
2873 | rt_runtime = RUNTIME_INF; | |
1a010e29 KK |
2874 | else if ((u64)rt_runtime_us > U64_MAX / NSEC_PER_USEC) |
2875 | return -EINVAL; | |
8887cd99 NP |
2876 | |
2877 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); | |
2878 | } | |
2879 | ||
2880 | long sched_group_rt_runtime(struct task_group *tg) | |
2881 | { | |
2882 | u64 rt_runtime_us; | |
2883 | ||
2884 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) | |
2885 | return -1; | |
2886 | ||
2887 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; | |
2888 | do_div(rt_runtime_us, NSEC_PER_USEC); | |
2889 | return rt_runtime_us; | |
2890 | } | |
2891 | ||
2892 | int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us) | |
2893 | { | |
2894 | u64 rt_runtime, rt_period; | |
2895 | ||
1a010e29 KK |
2896 | if (rt_period_us > U64_MAX / NSEC_PER_USEC) |
2897 | return -EINVAL; | |
2898 | ||
8887cd99 NP |
2899 | rt_period = rt_period_us * NSEC_PER_USEC; |
2900 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
2901 | ||
2902 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); | |
2903 | } | |
2904 | ||
2905 | long sched_group_rt_period(struct task_group *tg) | |
2906 | { | |
2907 | u64 rt_period_us; | |
2908 | ||
2909 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
2910 | do_div(rt_period_us, NSEC_PER_USEC); | |
2911 | return rt_period_us; | |
2912 | } | |
2913 | ||
28f152cd | 2914 | #ifdef CONFIG_SYSCTL |
8887cd99 NP |
2915 | static int sched_rt_global_constraints(void) |
2916 | { | |
2917 | int ret = 0; | |
2918 | ||
2919 | mutex_lock(&rt_constraints_mutex); | |
8887cd99 | 2920 | ret = __rt_schedulable(NULL, 0, 0); |
8887cd99 NP |
2921 | mutex_unlock(&rt_constraints_mutex); |
2922 | ||
2923 | return ret; | |
2924 | } | |
28f152cd | 2925 | #endif /* CONFIG_SYSCTL */ |
8887cd99 NP |
2926 | |
2927 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
2928 | { | |
2929 | /* Don't accept realtime tasks when there is no way for them to run */ | |
2930 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
2931 | return 0; | |
2932 | ||
2933 | return 1; | |
2934 | } | |
2935 | ||
2936 | #else /* !CONFIG_RT_GROUP_SCHED */ | |
28f152cd BZ |
2937 | |
2938 | #ifdef CONFIG_SYSCTL | |
8887cd99 NP |
2939 | static int sched_rt_global_constraints(void) |
2940 | { | |
2941 | unsigned long flags; | |
2942 | int i; | |
2943 | ||
2944 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); | |
2945 | for_each_possible_cpu(i) { | |
2946 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
2947 | ||
2948 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
2949 | rt_rq->rt_runtime = global_rt_runtime(); | |
2950 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
2951 | } | |
2952 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); | |
2953 | ||
2954 | return 0; | |
2955 | } | |
28f152cd | 2956 | #endif /* CONFIG_SYSCTL */ |
8887cd99 NP |
2957 | #endif /* CONFIG_RT_GROUP_SCHED */ |
2958 | ||
28f152cd | 2959 | #ifdef CONFIG_SYSCTL |
8887cd99 NP |
2960 | static int sched_rt_global_validate(void) |
2961 | { | |
2962 | if (sysctl_sched_rt_period <= 0) | |
2963 | return -EINVAL; | |
2964 | ||
2965 | if ((sysctl_sched_rt_runtime != RUNTIME_INF) && | |
d505b8af HC |
2966 | ((sysctl_sched_rt_runtime > sysctl_sched_rt_period) || |
2967 | ((u64)sysctl_sched_rt_runtime * | |
2968 | NSEC_PER_USEC > max_rt_runtime))) | |
8887cd99 NP |
2969 | return -EINVAL; |
2970 | ||
2971 | return 0; | |
2972 | } | |
2973 | ||
2974 | static void sched_rt_do_global(void) | |
2975 | { | |
9b58e976 LH |
2976 | unsigned long flags; |
2977 | ||
2978 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); | |
8887cd99 NP |
2979 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); |
2980 | def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); | |
9b58e976 | 2981 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
8887cd99 NP |
2982 | } |
2983 | ||
d9ab0e63 | 2984 | static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, |
32927393 | 2985 | size_t *lenp, loff_t *ppos) |
8887cd99 NP |
2986 | { |
2987 | int old_period, old_runtime; | |
2988 | static DEFINE_MUTEX(mutex); | |
2989 | int ret; | |
2990 | ||
2991 | mutex_lock(&mutex); | |
2992 | old_period = sysctl_sched_rt_period; | |
2993 | old_runtime = sysctl_sched_rt_runtime; | |
2994 | ||
2995 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
2996 | ||
2997 | if (!ret && write) { | |
2998 | ret = sched_rt_global_validate(); | |
2999 | if (ret) | |
3000 | goto undo; | |
3001 | ||
3002 | ret = sched_dl_global_validate(); | |
3003 | if (ret) | |
3004 | goto undo; | |
3005 | ||
3006 | ret = sched_rt_global_constraints(); | |
3007 | if (ret) | |
3008 | goto undo; | |
3009 | ||
3010 | sched_rt_do_global(); | |
3011 | sched_dl_do_global(); | |
3012 | } | |
3013 | if (0) { | |
3014 | undo: | |
3015 | sysctl_sched_rt_period = old_period; | |
3016 | sysctl_sched_rt_runtime = old_runtime; | |
3017 | } | |
3018 | mutex_unlock(&mutex); | |
3019 | ||
3020 | return ret; | |
3021 | } | |
3022 | ||
dafd7a9d | 3023 | static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, |
32927393 | 3024 | size_t *lenp, loff_t *ppos) |
8887cd99 NP |
3025 | { |
3026 | int ret; | |
3027 | static DEFINE_MUTEX(mutex); | |
3028 | ||
3029 | mutex_lock(&mutex); | |
3030 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
3031 | /* | |
3032 | * Make sure that internally we keep jiffies. | |
3033 | * Also, writing zero resets the timeslice to default: | |
3034 | */ | |
3035 | if (!ret && write) { | |
3036 | sched_rr_timeslice = | |
3037 | sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE : | |
3038 | msecs_to_jiffies(sysctl_sched_rr_timeslice); | |
3039 | } | |
3040 | mutex_unlock(&mutex); | |
97fb7a0a | 3041 | |
8887cd99 NP |
3042 | return ret; |
3043 | } | |
28f152cd | 3044 | #endif /* CONFIG_SYSCTL */ |
8887cd99 | 3045 | |
ada18de2 | 3046 | #ifdef CONFIG_SCHED_DEBUG |
029632fb | 3047 | void print_rt_stats(struct seq_file *m, int cpu) |
ada18de2 | 3048 | { |
ec514c48 | 3049 | rt_rq_iter_t iter; |
ada18de2 PZ |
3050 | struct rt_rq *rt_rq; |
3051 | ||
3052 | rcu_read_lock(); | |
ec514c48 | 3053 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) |
ada18de2 PZ |
3054 | print_rt_rq(m, cpu, rt_rq); |
3055 | rcu_read_unlock(); | |
3056 | } | |
55e12e5e | 3057 | #endif /* CONFIG_SCHED_DEBUG */ |