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 | */ | |
089768df | 19 | int sysctl_sched_rt_period = 1000000; |
d9ab0e63 ZN |
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 | 27 | #ifdef CONFIG_SYSCTL |
c7fcb998 | 28 | static int sysctl_sched_rr_timeslice = (MSEC_PER_SEC * RR_TIMESLICE) / HZ; |
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, | |
089768df | 37 | .maxlen = sizeof(int), |
d9ab0e63 ZN |
38 | .mode = 0644, |
39 | .proc_handler = sched_rt_handler, | |
079be8fc CH |
40 | .extra1 = SYSCTL_ONE, |
41 | .extra2 = SYSCTL_INT_MAX, | |
d9ab0e63 ZN |
42 | }, |
43 | { | |
44 | .procname = "sched_rt_runtime_us", | |
45 | .data = &sysctl_sched_rt_runtime, | |
46 | .maxlen = sizeof(int), | |
47 | .mode = 0644, | |
48 | .proc_handler = sched_rt_handler, | |
079be8fc | 49 | .extra1 = SYSCTL_NEG_ONE, |
089768df | 50 | .extra2 = (void *)&sysctl_sched_rt_period, |
d9ab0e63 | 51 | }, |
dafd7a9d ZN |
52 | { |
53 | .procname = "sched_rr_timeslice_ms", | |
54 | .data = &sysctl_sched_rr_timeslice, | |
55 | .maxlen = sizeof(int), | |
56 | .mode = 0644, | |
57 | .proc_handler = sched_rr_handler, | |
58 | }, | |
d9ab0e63 ZN |
59 | }; |
60 | ||
61 | static int __init sched_rt_sysctl_init(void) | |
62 | { | |
63 | register_sysctl_init("kernel", sched_rt_sysctls); | |
64 | return 0; | |
65 | } | |
66 | late_initcall(sched_rt_sysctl_init); | |
67 | #endif | |
68 | ||
029632fb PZ |
69 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) |
70 | { | |
71 | struct rt_bandwidth *rt_b = | |
72 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
029632fb | 73 | int idle = 0; |
77a4d1a1 | 74 | int overrun; |
029632fb | 75 | |
77a4d1a1 | 76 | raw_spin_lock(&rt_b->rt_runtime_lock); |
029632fb | 77 | for (;;) { |
77a4d1a1 | 78 | overrun = hrtimer_forward_now(timer, rt_b->rt_period); |
029632fb PZ |
79 | if (!overrun) |
80 | break; | |
81 | ||
77a4d1a1 | 82 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
029632fb | 83 | idle = do_sched_rt_period_timer(rt_b, overrun); |
77a4d1a1 | 84 | raw_spin_lock(&rt_b->rt_runtime_lock); |
029632fb | 85 | } |
4cfafd30 PZ |
86 | if (idle) |
87 | rt_b->rt_period_active = 0; | |
77a4d1a1 | 88 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
029632fb PZ |
89 | |
90 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
91 | } | |
92 | ||
93 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
94 | { | |
95 | rt_b->rt_period = ns_to_ktime(period); | |
96 | rt_b->rt_runtime = runtime; | |
97 | ||
98 | raw_spin_lock_init(&rt_b->rt_runtime_lock); | |
99 | ||
d5096aa6 SAS |
100 | hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC, |
101 | HRTIMER_MODE_REL_HARD); | |
029632fb PZ |
102 | rt_b->rt_period_timer.function = sched_rt_period_timer; |
103 | } | |
104 | ||
9b58e976 | 105 | static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b) |
029632fb | 106 | { |
029632fb | 107 | raw_spin_lock(&rt_b->rt_runtime_lock); |
4cfafd30 PZ |
108 | if (!rt_b->rt_period_active) { |
109 | rt_b->rt_period_active = 1; | |
c3a990dc SR |
110 | /* |
111 | * SCHED_DEADLINE updates the bandwidth, as a run away | |
112 | * RT task with a DL task could hog a CPU. But DL does | |
113 | * not reset the period. If a deadline task was running | |
114 | * without an RT task running, it can cause RT tasks to | |
115 | * throttle when they start up. Kick the timer right away | |
116 | * to update the period. | |
117 | */ | |
118 | hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0)); | |
d5096aa6 SAS |
119 | hrtimer_start_expires(&rt_b->rt_period_timer, |
120 | HRTIMER_MODE_ABS_PINNED_HARD); | |
4cfafd30 | 121 | } |
029632fb PZ |
122 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
123 | } | |
124 | ||
9b58e976 LH |
125 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) |
126 | { | |
127 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) | |
128 | return; | |
129 | ||
130 | do_start_rt_bandwidth(rt_b); | |
131 | } | |
132 | ||
07c54f7a | 133 | void init_rt_rq(struct rt_rq *rt_rq) |
029632fb PZ |
134 | { |
135 | struct rt_prio_array *array; | |
136 | int i; | |
137 | ||
138 | array = &rt_rq->active; | |
139 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
140 | INIT_LIST_HEAD(array->queue + i); | |
141 | __clear_bit(i, array->bitmap); | |
142 | } | |
143 | /* delimiter for bitsearch: */ | |
144 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
145 | ||
146 | #if defined CONFIG_SMP | |
934fc331 PZ |
147 | rt_rq->highest_prio.curr = MAX_RT_PRIO-1; |
148 | rt_rq->highest_prio.next = MAX_RT_PRIO-1; | |
029632fb PZ |
149 | rt_rq->overloaded = 0; |
150 | plist_head_init(&rt_rq->pushable_tasks); | |
b6366f04 | 151 | #endif /* CONFIG_SMP */ |
f4ebcbc0 KT |
152 | /* We start is dequeued state, because no RT tasks are queued */ |
153 | rt_rq->rt_queued = 0; | |
029632fb PZ |
154 | |
155 | rt_rq->rt_time = 0; | |
156 | rt_rq->rt_throttled = 0; | |
157 | rt_rq->rt_runtime = 0; | |
158 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); | |
159 | } | |
160 | ||
8f48894f | 161 | #ifdef CONFIG_RT_GROUP_SCHED |
029632fb PZ |
162 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) |
163 | { | |
164 | hrtimer_cancel(&rt_b->rt_period_timer); | |
165 | } | |
8f48894f PZ |
166 | |
167 | #define rt_entity_is_task(rt_se) (!(rt_se)->my_q) | |
168 | ||
398a153b GH |
169 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
170 | { | |
8f48894f PZ |
171 | #ifdef CONFIG_SCHED_DEBUG |
172 | WARN_ON_ONCE(!rt_entity_is_task(rt_se)); | |
173 | #endif | |
398a153b GH |
174 | return container_of(rt_se, struct task_struct, rt); |
175 | } | |
176 | ||
398a153b GH |
177 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
178 | { | |
179 | return rt_rq->rq; | |
180 | } | |
181 | ||
182 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
183 | { | |
184 | return rt_se->rt_rq; | |
185 | } | |
186 | ||
653d07a6 KT |
187 | static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) |
188 | { | |
189 | struct rt_rq *rt_rq = rt_se->rt_rq; | |
190 | ||
191 | return rt_rq->rq; | |
192 | } | |
193 | ||
b027789e | 194 | void unregister_rt_sched_group(struct task_group *tg) |
029632fb | 195 | { |
029632fb PZ |
196 | if (tg->rt_se) |
197 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
198 | ||
b027789e MK |
199 | } |
200 | ||
201 | void free_rt_sched_group(struct task_group *tg) | |
202 | { | |
203 | int i; | |
204 | ||
029632fb PZ |
205 | for_each_possible_cpu(i) { |
206 | if (tg->rt_rq) | |
207 | kfree(tg->rt_rq[i]); | |
208 | if (tg->rt_se) | |
209 | kfree(tg->rt_se[i]); | |
210 | } | |
211 | ||
212 | kfree(tg->rt_rq); | |
213 | kfree(tg->rt_se); | |
214 | } | |
215 | ||
216 | void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, | |
217 | struct sched_rt_entity *rt_se, int cpu, | |
218 | struct sched_rt_entity *parent) | |
219 | { | |
220 | struct rq *rq = cpu_rq(cpu); | |
221 | ||
934fc331 | 222 | rt_rq->highest_prio.curr = MAX_RT_PRIO-1; |
029632fb PZ |
223 | rt_rq->rt_nr_boosted = 0; |
224 | rt_rq->rq = rq; | |
225 | rt_rq->tg = tg; | |
226 | ||
227 | tg->rt_rq[cpu] = rt_rq; | |
228 | tg->rt_se[cpu] = rt_se; | |
229 | ||
230 | if (!rt_se) | |
231 | return; | |
232 | ||
233 | if (!parent) | |
234 | rt_se->rt_rq = &rq->rt; | |
235 | else | |
236 | rt_se->rt_rq = parent->my_q; | |
237 | ||
238 | rt_se->my_q = rt_rq; | |
239 | rt_se->parent = parent; | |
240 | INIT_LIST_HEAD(&rt_se->run_list); | |
241 | } | |
242 | ||
243 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
244 | { | |
245 | struct rt_rq *rt_rq; | |
246 | struct sched_rt_entity *rt_se; | |
247 | int i; | |
248 | ||
6396bb22 | 249 | tg->rt_rq = kcalloc(nr_cpu_ids, sizeof(rt_rq), GFP_KERNEL); |
029632fb PZ |
250 | if (!tg->rt_rq) |
251 | goto err; | |
6396bb22 | 252 | tg->rt_se = kcalloc(nr_cpu_ids, sizeof(rt_se), GFP_KERNEL); |
029632fb PZ |
253 | if (!tg->rt_se) |
254 | goto err; | |
255 | ||
256 | init_rt_bandwidth(&tg->rt_bandwidth, | |
257 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
258 | ||
259 | for_each_possible_cpu(i) { | |
260 | rt_rq = kzalloc_node(sizeof(struct rt_rq), | |
261 | GFP_KERNEL, cpu_to_node(i)); | |
262 | if (!rt_rq) | |
263 | goto err; | |
264 | ||
265 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), | |
266 | GFP_KERNEL, cpu_to_node(i)); | |
267 | if (!rt_se) | |
268 | goto err_free_rq; | |
269 | ||
07c54f7a | 270 | init_rt_rq(rt_rq); |
029632fb PZ |
271 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
272 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); | |
273 | } | |
274 | ||
275 | return 1; | |
276 | ||
277 | err_free_rq: | |
278 | kfree(rt_rq); | |
279 | err: | |
280 | return 0; | |
281 | } | |
282 | ||
398a153b GH |
283 | #else /* CONFIG_RT_GROUP_SCHED */ |
284 | ||
a1ba4d8b PZ |
285 | #define rt_entity_is_task(rt_se) (1) |
286 | ||
8f48894f PZ |
287 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
288 | { | |
289 | return container_of(rt_se, struct task_struct, rt); | |
290 | } | |
291 | ||
398a153b GH |
292 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
293 | { | |
294 | return container_of(rt_rq, struct rq, rt); | |
295 | } | |
296 | ||
653d07a6 | 297 | static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se) |
398a153b GH |
298 | { |
299 | struct task_struct *p = rt_task_of(rt_se); | |
653d07a6 KT |
300 | |
301 | return task_rq(p); | |
302 | } | |
303 | ||
304 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
305 | { | |
306 | struct rq *rq = rq_of_rt_se(rt_se); | |
398a153b GH |
307 | |
308 | return &rq->rt; | |
309 | } | |
310 | ||
b027789e MK |
311 | void unregister_rt_sched_group(struct task_group *tg) { } |
312 | ||
029632fb PZ |
313 | void free_rt_sched_group(struct task_group *tg) { } |
314 | ||
315 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
316 | { | |
317 | return 1; | |
318 | } | |
398a153b GH |
319 | #endif /* CONFIG_RT_GROUP_SCHED */ |
320 | ||
4fd29176 | 321 | #ifdef CONFIG_SMP |
84de4274 | 322 | |
dc877341 PZ |
323 | static inline bool need_pull_rt_task(struct rq *rq, struct task_struct *prev) |
324 | { | |
325 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
120455c5 | 326 | return rq->online && rq->rt.highest_prio.curr > prev->prio; |
dc877341 PZ |
327 | } |
328 | ||
637f5085 | 329 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 330 | { |
637f5085 | 331 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 332 | } |
84de4274 | 333 | |
4fd29176 SR |
334 | static inline void rt_set_overload(struct rq *rq) |
335 | { | |
1f11eb6a GH |
336 | if (!rq->online) |
337 | return; | |
338 | ||
c6c4927b | 339 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
340 | /* |
341 | * Make sure the mask is visible before we set | |
342 | * the overload count. That is checked to determine | |
343 | * if we should look at the mask. It would be a shame | |
344 | * if we looked at the mask, but the mask was not | |
345 | * updated yet. | |
7c3f2ab7 PZ |
346 | * |
347 | * Matched by the barrier in pull_rt_task(). | |
4fd29176 | 348 | */ |
7c3f2ab7 | 349 | smp_wmb(); |
637f5085 | 350 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 351 | } |
84de4274 | 352 | |
4fd29176 SR |
353 | static inline void rt_clear_overload(struct rq *rq) |
354 | { | |
1f11eb6a GH |
355 | if (!rq->online) |
356 | return; | |
357 | ||
4fd29176 | 358 | /* the order here really doesn't matter */ |
637f5085 | 359 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 360 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 361 | } |
73fe6aae | 362 | |
5181f4a4 SR |
363 | static inline int has_pushable_tasks(struct rq *rq) |
364 | { | |
365 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
366 | } | |
367 | ||
8e5bad7d KC |
368 | static DEFINE_PER_CPU(struct balance_callback, rt_push_head); |
369 | static DEFINE_PER_CPU(struct balance_callback, rt_pull_head); | |
e3fca9e7 PZ |
370 | |
371 | static void push_rt_tasks(struct rq *); | |
fd7a4bed | 372 | static void pull_rt_task(struct rq *); |
e3fca9e7 | 373 | |
02d8ec94 | 374 | static inline void rt_queue_push_tasks(struct rq *rq) |
dc877341 | 375 | { |
e3fca9e7 PZ |
376 | if (!has_pushable_tasks(rq)) |
377 | return; | |
378 | ||
fd7a4bed PZ |
379 | queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks); |
380 | } | |
381 | ||
02d8ec94 | 382 | static inline void rt_queue_pull_task(struct rq *rq) |
fd7a4bed PZ |
383 | { |
384 | queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task); | |
dc877341 PZ |
385 | } |
386 | ||
917b627d GH |
387 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
388 | { | |
389 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
390 | plist_node_init(&p->pushable_tasks, p->prio); | |
391 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
5181f4a4 SR |
392 | |
393 | /* Update the highest prio pushable task */ | |
394 | if (p->prio < rq->rt.highest_prio.next) | |
395 | rq->rt.highest_prio.next = p->prio; | |
612f769e VS |
396 | |
397 | if (!rq->rt.overloaded) { | |
398 | rt_set_overload(rq); | |
399 | rq->rt.overloaded = 1; | |
400 | } | |
917b627d GH |
401 | } |
402 | ||
403 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
404 | { | |
405 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
917b627d | 406 | |
5181f4a4 SR |
407 | /* Update the new highest prio pushable task */ |
408 | if (has_pushable_tasks(rq)) { | |
409 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
410 | struct task_struct, pushable_tasks); | |
411 | rq->rt.highest_prio.next = p->prio; | |
934fc331 PZ |
412 | } else { |
413 | rq->rt.highest_prio.next = MAX_RT_PRIO-1; | |
612f769e VS |
414 | |
415 | if (rq->rt.overloaded) { | |
416 | rt_clear_overload(rq); | |
417 | rq->rt.overloaded = 0; | |
418 | } | |
934fc331 | 419 | } |
bcf08df3 IM |
420 | } |
421 | ||
917b627d GH |
422 | #else |
423 | ||
ceacc2c1 | 424 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
fa85ae24 | 425 | { |
6f505b16 PZ |
426 | } |
427 | ||
ceacc2c1 PZ |
428 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
429 | { | |
430 | } | |
431 | ||
02d8ec94 | 432 | static inline void rt_queue_push_tasks(struct rq *rq) |
dc877341 PZ |
433 | { |
434 | } | |
4fd29176 SR |
435 | #endif /* CONFIG_SMP */ |
436 | ||
f4ebcbc0 | 437 | static void enqueue_top_rt_rq(struct rt_rq *rt_rq); |
5c66d1b9 | 438 | static void dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count); |
f4ebcbc0 | 439 | |
6f505b16 PZ |
440 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
441 | { | |
ff77e468 | 442 | return rt_se->on_rq; |
6f505b16 PZ |
443 | } |
444 | ||
804d402f QY |
445 | #ifdef CONFIG_UCLAMP_TASK |
446 | /* | |
447 | * Verify the fitness of task @p to run on @cpu taking into account the uclamp | |
448 | * settings. | |
449 | * | |
450 | * This check is only important for heterogeneous systems where uclamp_min value | |
451 | * is higher than the capacity of a @cpu. For non-heterogeneous system this | |
452 | * function will always return true. | |
453 | * | |
454 | * The function will return true if the capacity of the @cpu is >= the | |
455 | * uclamp_min and false otherwise. | |
456 | * | |
457 | * Note that uclamp_min will be clamped to uclamp_max if uclamp_min | |
458 | * > uclamp_max. | |
459 | */ | |
460 | static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) | |
461 | { | |
462 | unsigned int min_cap; | |
463 | unsigned int max_cap; | |
464 | unsigned int cpu_cap; | |
465 | ||
466 | /* Only heterogeneous systems can benefit from this check */ | |
740cf8a7 | 467 | if (!sched_asym_cpucap_active()) |
804d402f QY |
468 | return true; |
469 | ||
470 | min_cap = uclamp_eff_value(p, UCLAMP_MIN); | |
471 | max_cap = uclamp_eff_value(p, UCLAMP_MAX); | |
472 | ||
7bc26384 | 473 | cpu_cap = arch_scale_cpu_capacity(cpu); |
804d402f QY |
474 | |
475 | return cpu_cap >= min(min_cap, max_cap); | |
476 | } | |
477 | #else | |
478 | static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) | |
479 | { | |
480 | return true; | |
481 | } | |
482 | #endif | |
483 | ||
052f1dc7 | 484 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 485 | |
9f0c1e56 | 486 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
487 | { |
488 | if (!rt_rq->tg) | |
9f0c1e56 | 489 | return RUNTIME_INF; |
6f505b16 | 490 | |
ac086bc2 PZ |
491 | return rt_rq->rt_runtime; |
492 | } | |
493 | ||
494 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
495 | { | |
496 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
497 | } |
498 | ||
ec514c48 CX |
499 | typedef struct task_group *rt_rq_iter_t; |
500 | ||
1c09ab0d YZ |
501 | static inline struct task_group *next_task_group(struct task_group *tg) |
502 | { | |
503 | do { | |
504 | tg = list_entry_rcu(tg->list.next, | |
505 | typeof(struct task_group), list); | |
506 | } while (&tg->list != &task_groups && task_group_is_autogroup(tg)); | |
507 | ||
508 | if (&tg->list == &task_groups) | |
509 | tg = NULL; | |
510 | ||
511 | return tg; | |
512 | } | |
513 | ||
514 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
515 | for (iter = container_of(&task_groups, typeof(*iter), list); \ | |
516 | (iter = next_task_group(iter)) && \ | |
517 | (rt_rq = iter->rt_rq[cpu_of(rq)]);) | |
ec514c48 | 518 | |
6f505b16 PZ |
519 | #define for_each_sched_rt_entity(rt_se) \ |
520 | for (; rt_se; rt_se = rt_se->parent) | |
521 | ||
522 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
523 | { | |
524 | return rt_se->my_q; | |
525 | } | |
526 | ||
ff77e468 PZ |
527 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); |
528 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags); | |
6f505b16 | 529 | |
9f0c1e56 | 530 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 531 | { |
f6121f4f | 532 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
8875125e | 533 | struct rq *rq = rq_of_rt_rq(rt_rq); |
74b7eb58 YZ |
534 | struct sched_rt_entity *rt_se; |
535 | ||
8875125e | 536 | int cpu = cpu_of(rq); |
0c3b9168 BS |
537 | |
538 | rt_se = rt_rq->tg->rt_se[cpu]; | |
6f505b16 | 539 | |
f6121f4f | 540 | if (rt_rq->rt_nr_running) { |
f4ebcbc0 KT |
541 | if (!rt_se) |
542 | enqueue_top_rt_rq(rt_rq); | |
543 | else if (!on_rt_rq(rt_se)) | |
ff77e468 | 544 | enqueue_rt_entity(rt_se, 0); |
f4ebcbc0 | 545 | |
e864c499 | 546 | if (rt_rq->highest_prio.curr < curr->prio) |
8875125e | 547 | resched_curr(rq); |
6f505b16 PZ |
548 | } |
549 | } | |
550 | ||
9f0c1e56 | 551 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 552 | { |
74b7eb58 | 553 | struct sched_rt_entity *rt_se; |
0c3b9168 | 554 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
74b7eb58 | 555 | |
0c3b9168 | 556 | rt_se = rt_rq->tg->rt_se[cpu]; |
6f505b16 | 557 | |
296b2ffe | 558 | if (!rt_se) { |
5c66d1b9 | 559 | dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); |
296b2ffe VG |
560 | /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ |
561 | cpufreq_update_util(rq_of_rt_rq(rt_rq), 0); | |
562 | } | |
f4ebcbc0 | 563 | else if (on_rt_rq(rt_se)) |
ff77e468 | 564 | dequeue_rt_entity(rt_se, 0); |
6f505b16 PZ |
565 | } |
566 | ||
46383648 KT |
567 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
568 | { | |
569 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
570 | } | |
571 | ||
23b0fdfc PZ |
572 | static int rt_se_boosted(struct sched_rt_entity *rt_se) |
573 | { | |
574 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
575 | struct task_struct *p; | |
576 | ||
577 | if (rt_rq) | |
578 | return !!rt_rq->rt_nr_boosted; | |
579 | ||
580 | p = rt_task_of(rt_se); | |
581 | return p->prio != p->normal_prio; | |
582 | } | |
583 | ||
d0b27fa7 | 584 | #ifdef CONFIG_SMP |
c6c4927b | 585 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 586 | { |
424c93fe | 587 | return this_rq()->rd->span; |
d0b27fa7 | 588 | } |
6f505b16 | 589 | #else |
c6c4927b | 590 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 591 | { |
c6c4927b | 592 | return cpu_online_mask; |
d0b27fa7 PZ |
593 | } |
594 | #endif | |
6f505b16 | 595 | |
d0b27fa7 PZ |
596 | static inline |
597 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 598 | { |
d0b27fa7 PZ |
599 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
600 | } | |
9f0c1e56 | 601 | |
ac086bc2 PZ |
602 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
603 | { | |
604 | return &rt_rq->tg->rt_bandwidth; | |
605 | } | |
606 | ||
55e12e5e | 607 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
608 | |
609 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
610 | { | |
ac086bc2 PZ |
611 | return rt_rq->rt_runtime; |
612 | } | |
613 | ||
614 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
615 | { | |
616 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
617 | } |
618 | ||
ec514c48 CX |
619 | typedef struct rt_rq *rt_rq_iter_t; |
620 | ||
621 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
622 | for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
623 | ||
6f505b16 PZ |
624 | #define for_each_sched_rt_entity(rt_se) \ |
625 | for (; rt_se; rt_se = NULL) | |
626 | ||
627 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
628 | { | |
629 | return NULL; | |
630 | } | |
631 | ||
9f0c1e56 | 632 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 633 | { |
f4ebcbc0 KT |
634 | struct rq *rq = rq_of_rt_rq(rt_rq); |
635 | ||
636 | if (!rt_rq->rt_nr_running) | |
637 | return; | |
638 | ||
639 | enqueue_top_rt_rq(rt_rq); | |
8875125e | 640 | resched_curr(rq); |
6f505b16 PZ |
641 | } |
642 | ||
9f0c1e56 | 643 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 644 | { |
5c66d1b9 | 645 | dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); |
6f505b16 PZ |
646 | } |
647 | ||
46383648 KT |
648 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
649 | { | |
650 | return rt_rq->rt_throttled; | |
651 | } | |
652 | ||
c6c4927b | 653 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 654 | { |
c6c4927b | 655 | return cpu_online_mask; |
d0b27fa7 PZ |
656 | } |
657 | ||
658 | static inline | |
659 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
660 | { | |
661 | return &cpu_rq(cpu)->rt; | |
662 | } | |
663 | ||
ac086bc2 PZ |
664 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
665 | { | |
666 | return &def_rt_bandwidth; | |
667 | } | |
668 | ||
55e12e5e | 669 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 670 | |
faa59937 JL |
671 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) |
672 | { | |
673 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
674 | ||
675 | return (hrtimer_active(&rt_b->rt_period_timer) || | |
676 | rt_rq->rt_time < rt_b->rt_runtime); | |
677 | } | |
678 | ||
ac086bc2 | 679 | #ifdef CONFIG_SMP |
78333cdd PZ |
680 | /* |
681 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
682 | */ | |
269b26a5 | 683 | static void do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
684 | { |
685 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
aa7f6730 | 686 | struct root_domain *rd = rq_of_rt_rq(rt_rq)->rd; |
269b26a5 | 687 | int i, weight; |
ac086bc2 PZ |
688 | u64 rt_period; |
689 | ||
c6c4927b | 690 | weight = cpumask_weight(rd->span); |
ac086bc2 | 691 | |
0986b11b | 692 | raw_spin_lock(&rt_b->rt_runtime_lock); |
ac086bc2 | 693 | rt_period = ktime_to_ns(rt_b->rt_period); |
c6c4927b | 694 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
695 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
696 | s64 diff; | |
697 | ||
698 | if (iter == rt_rq) | |
699 | continue; | |
700 | ||
0986b11b | 701 | raw_spin_lock(&iter->rt_runtime_lock); |
78333cdd PZ |
702 | /* |
703 | * Either all rqs have inf runtime and there's nothing to steal | |
704 | * or __disable_runtime() below sets a specific rq to inf to | |
3b03706f | 705 | * indicate its been disabled and disallow stealing. |
78333cdd | 706 | */ |
7def2be1 PZ |
707 | if (iter->rt_runtime == RUNTIME_INF) |
708 | goto next; | |
709 | ||
78333cdd PZ |
710 | /* |
711 | * From runqueues with spare time, take 1/n part of their | |
712 | * spare time, but no more than our period. | |
713 | */ | |
ac086bc2 PZ |
714 | diff = iter->rt_runtime - iter->rt_time; |
715 | if (diff > 0) { | |
58838cf3 | 716 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
717 | if (rt_rq->rt_runtime + diff > rt_period) |
718 | diff = rt_period - rt_rq->rt_runtime; | |
719 | iter->rt_runtime -= diff; | |
720 | rt_rq->rt_runtime += diff; | |
ac086bc2 | 721 | if (rt_rq->rt_runtime == rt_period) { |
0986b11b | 722 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 PZ |
723 | break; |
724 | } | |
725 | } | |
7def2be1 | 726 | next: |
0986b11b | 727 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 | 728 | } |
0986b11b | 729 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
ac086bc2 | 730 | } |
7def2be1 | 731 | |
78333cdd PZ |
732 | /* |
733 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
734 | */ | |
7def2be1 PZ |
735 | static void __disable_runtime(struct rq *rq) |
736 | { | |
737 | struct root_domain *rd = rq->rd; | |
ec514c48 | 738 | rt_rq_iter_t iter; |
7def2be1 PZ |
739 | struct rt_rq *rt_rq; |
740 | ||
741 | if (unlikely(!scheduler_running)) | |
742 | return; | |
743 | ||
ec514c48 | 744 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
745 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
746 | s64 want; | |
747 | int i; | |
748 | ||
0986b11b TG |
749 | raw_spin_lock(&rt_b->rt_runtime_lock); |
750 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
751 | /* |
752 | * Either we're all inf and nobody needs to borrow, or we're | |
753 | * already disabled and thus have nothing to do, or we have | |
754 | * exactly the right amount of runtime to take out. | |
755 | */ | |
7def2be1 PZ |
756 | if (rt_rq->rt_runtime == RUNTIME_INF || |
757 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
758 | goto balanced; | |
0986b11b | 759 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
7def2be1 | 760 | |
78333cdd PZ |
761 | /* |
762 | * Calculate the difference between what we started out with | |
763 | * and what we current have, that's the amount of runtime | |
764 | * we lend and now have to reclaim. | |
765 | */ | |
7def2be1 PZ |
766 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
767 | ||
78333cdd PZ |
768 | /* |
769 | * Greedy reclaim, take back as much as we can. | |
770 | */ | |
c6c4927b | 771 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
772 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
773 | s64 diff; | |
774 | ||
78333cdd PZ |
775 | /* |
776 | * Can't reclaim from ourselves or disabled runqueues. | |
777 | */ | |
f1679d08 | 778 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
779 | continue; |
780 | ||
0986b11b | 781 | raw_spin_lock(&iter->rt_runtime_lock); |
7def2be1 PZ |
782 | if (want > 0) { |
783 | diff = min_t(s64, iter->rt_runtime, want); | |
784 | iter->rt_runtime -= diff; | |
785 | want -= diff; | |
786 | } else { | |
787 | iter->rt_runtime -= want; | |
788 | want -= want; | |
789 | } | |
0986b11b | 790 | raw_spin_unlock(&iter->rt_runtime_lock); |
7def2be1 PZ |
791 | |
792 | if (!want) | |
793 | break; | |
794 | } | |
795 | ||
0986b11b | 796 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
78333cdd PZ |
797 | /* |
798 | * We cannot be left wanting - that would mean some runtime | |
799 | * leaked out of the system. | |
800 | */ | |
09348d75 | 801 | WARN_ON_ONCE(want); |
7def2be1 | 802 | balanced: |
78333cdd PZ |
803 | /* |
804 | * Disable all the borrow logic by pretending we have inf | |
805 | * runtime - in which case borrowing doesn't make sense. | |
806 | */ | |
7def2be1 | 807 | rt_rq->rt_runtime = RUNTIME_INF; |
a4c96ae3 | 808 | rt_rq->rt_throttled = 0; |
0986b11b TG |
809 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
810 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
99b62567 KT |
811 | |
812 | /* Make rt_rq available for pick_next_task() */ | |
813 | sched_rt_rq_enqueue(rt_rq); | |
7def2be1 PZ |
814 | } |
815 | } | |
816 | ||
7def2be1 PZ |
817 | static void __enable_runtime(struct rq *rq) |
818 | { | |
ec514c48 | 819 | rt_rq_iter_t iter; |
7def2be1 PZ |
820 | struct rt_rq *rt_rq; |
821 | ||
822 | if (unlikely(!scheduler_running)) | |
823 | return; | |
824 | ||
78333cdd PZ |
825 | /* |
826 | * Reset each runqueue's bandwidth settings | |
827 | */ | |
ec514c48 | 828 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
829 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
830 | ||
0986b11b TG |
831 | raw_spin_lock(&rt_b->rt_runtime_lock); |
832 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
7def2be1 PZ |
833 | rt_rq->rt_runtime = rt_b->rt_runtime; |
834 | rt_rq->rt_time = 0; | |
baf25731 | 835 | rt_rq->rt_throttled = 0; |
0986b11b TG |
836 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
837 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
838 | } |
839 | } | |
840 | ||
269b26a5 | 841 | static void balance_runtime(struct rt_rq *rt_rq) |
eff6549b | 842 | { |
4a6184ce | 843 | if (!sched_feat(RT_RUNTIME_SHARE)) |
269b26a5 | 844 | return; |
4a6184ce | 845 | |
eff6549b | 846 | if (rt_rq->rt_time > rt_rq->rt_runtime) { |
0986b11b | 847 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
269b26a5 | 848 | do_balance_runtime(rt_rq); |
0986b11b | 849 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b | 850 | } |
eff6549b | 851 | } |
55e12e5e | 852 | #else /* !CONFIG_SMP */ |
269b26a5 | 853 | static inline void balance_runtime(struct rt_rq *rt_rq) {} |
55e12e5e | 854 | #endif /* CONFIG_SMP */ |
ac086bc2 | 855 | |
eff6549b PZ |
856 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
857 | { | |
42c62a58 | 858 | int i, idle = 1, throttled = 0; |
c6c4927b | 859 | const struct cpumask *span; |
eff6549b | 860 | |
eff6549b | 861 | span = sched_rt_period_mask(); |
e221d028 MG |
862 | #ifdef CONFIG_RT_GROUP_SCHED |
863 | /* | |
864 | * FIXME: isolated CPUs should really leave the root task group, | |
865 | * whether they are isolcpus or were isolated via cpusets, lest | |
866 | * the timer run on a CPU which does not service all runqueues, | |
867 | * potentially leaving other CPUs indefinitely throttled. If | |
868 | * isolation is really required, the user will turn the throttle | |
869 | * off to kill the perturbations it causes anyway. Meanwhile, | |
870 | * this maintains functionality for boot and/or troubleshooting. | |
871 | */ | |
872 | if (rt_b == &root_task_group.rt_bandwidth) | |
873 | span = cpu_online_mask; | |
874 | #endif | |
c6c4927b | 875 | for_each_cpu(i, span) { |
eff6549b PZ |
876 | int enqueue = 0; |
877 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
878 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
2679a837 | 879 | struct rq_flags rf; |
c249f255 DK |
880 | int skip; |
881 | ||
882 | /* | |
883 | * When span == cpu_online_mask, taking each rq->lock | |
884 | * can be time-consuming. Try to avoid it when possible. | |
885 | */ | |
886 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
f3d133ee HL |
887 | if (!sched_feat(RT_RUNTIME_SHARE) && rt_rq->rt_runtime != RUNTIME_INF) |
888 | rt_rq->rt_runtime = rt_b->rt_runtime; | |
c249f255 DK |
889 | skip = !rt_rq->rt_time && !rt_rq->rt_nr_running; |
890 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
891 | if (skip) | |
892 | continue; | |
eff6549b | 893 | |
2679a837 | 894 | rq_lock(rq, &rf); |
d29a2064 DB |
895 | update_rq_clock(rq); |
896 | ||
eff6549b PZ |
897 | if (rt_rq->rt_time) { |
898 | u64 runtime; | |
899 | ||
0986b11b | 900 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
901 | if (rt_rq->rt_throttled) |
902 | balance_runtime(rt_rq); | |
903 | runtime = rt_rq->rt_runtime; | |
904 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
905 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
906 | rt_rq->rt_throttled = 0; | |
907 | enqueue = 1; | |
61eadef6 MG |
908 | |
909 | /* | |
9edfbfed | 910 | * When we're idle and a woken (rt) task is |
e23edc86 | 911 | * throttled wakeup_preempt() will set |
9edfbfed PZ |
912 | * skip_update and the time between the wakeup |
913 | * and this unthrottle will get accounted as | |
914 | * 'runtime'. | |
61eadef6 MG |
915 | */ |
916 | if (rt_rq->rt_nr_running && rq->curr == rq->idle) | |
adcc8da8 | 917 | rq_clock_cancel_skipupdate(rq); |
eff6549b PZ |
918 | } |
919 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
920 | idle = 0; | |
0986b11b | 921 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
0c3b9168 | 922 | } else if (rt_rq->rt_nr_running) { |
6c3df255 | 923 | idle = 0; |
0c3b9168 BS |
924 | if (!rt_rq_throttled(rt_rq)) |
925 | enqueue = 1; | |
926 | } | |
42c62a58 PZ |
927 | if (rt_rq->rt_throttled) |
928 | throttled = 1; | |
eff6549b PZ |
929 | |
930 | if (enqueue) | |
931 | sched_rt_rq_enqueue(rt_rq); | |
2679a837 | 932 | rq_unlock(rq, &rf); |
eff6549b PZ |
933 | } |
934 | ||
42c62a58 PZ |
935 | if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) |
936 | return 1; | |
937 | ||
eff6549b PZ |
938 | return idle; |
939 | } | |
ac086bc2 | 940 | |
6f505b16 PZ |
941 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
942 | { | |
052f1dc7 | 943 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
944 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
945 | ||
946 | if (rt_rq) | |
e864c499 | 947 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
948 | #endif |
949 | ||
950 | return rt_task_of(rt_se)->prio; | |
951 | } | |
952 | ||
9f0c1e56 | 953 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 954 | { |
9f0c1e56 | 955 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 956 | |
fa85ae24 | 957 | if (rt_rq->rt_throttled) |
23b0fdfc | 958 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 959 | |
5b680fd6 | 960 | if (runtime >= sched_rt_period(rt_rq)) |
ac086bc2 PZ |
961 | return 0; |
962 | ||
b79f3833 PZ |
963 | balance_runtime(rt_rq); |
964 | runtime = sched_rt_runtime(rt_rq); | |
965 | if (runtime == RUNTIME_INF) | |
966 | return 0; | |
ac086bc2 | 967 | |
9f0c1e56 | 968 | if (rt_rq->rt_time > runtime) { |
7abc63b1 PZ |
969 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
970 | ||
971 | /* | |
972 | * Don't actually throttle groups that have no runtime assigned | |
973 | * but accrue some time due to boosting. | |
974 | */ | |
975 | if (likely(rt_b->rt_runtime)) { | |
976 | rt_rq->rt_throttled = 1; | |
c224815d | 977 | printk_deferred_once("sched: RT throttling activated\n"); |
7abc63b1 PZ |
978 | } else { |
979 | /* | |
980 | * In case we did anyway, make it go away, | |
981 | * replenishment is a joke, since it will replenish us | |
982 | * with exactly 0 ns. | |
983 | */ | |
984 | rt_rq->rt_time = 0; | |
985 | } | |
986 | ||
23b0fdfc | 987 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 988 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
989 | return 1; |
990 | } | |
fa85ae24 PZ |
991 | } |
992 | ||
993 | return 0; | |
994 | } | |
995 | ||
bb44e5d1 IM |
996 | /* |
997 | * Update the current task's runtime statistics. Skip current tasks that | |
998 | * are not in our scheduling class. | |
999 | */ | |
a9957449 | 1000 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
1001 | { |
1002 | struct task_struct *curr = rq->curr; | |
6f505b16 | 1003 | struct sched_rt_entity *rt_se = &curr->rt; |
5d69eca5 | 1004 | s64 delta_exec; |
bb44e5d1 | 1005 | |
06c3bc65 | 1006 | if (curr->sched_class != &rt_sched_class) |
bb44e5d1 IM |
1007 | return; |
1008 | ||
5d69eca5 PZ |
1009 | delta_exec = update_curr_common(rq); |
1010 | if (unlikely(delta_exec <= 0)) | |
fc79e240 | 1011 | return; |
6cfb0d5d | 1012 | |
0b148fa0 PZ |
1013 | if (!rt_bandwidth_enabled()) |
1014 | return; | |
1015 | ||
354d60c2 | 1016 | for_each_sched_rt_entity(rt_se) { |
0b07939c | 1017 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
9b58e976 | 1018 | int exceeded; |
354d60c2 | 1019 | |
cc2991cf | 1020 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
0986b11b | 1021 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf | 1022 | rt_rq->rt_time += delta_exec; |
9b58e976 LH |
1023 | exceeded = sched_rt_runtime_exceeded(rt_rq); |
1024 | if (exceeded) | |
8875125e | 1025 | resched_curr(rq); |
0986b11b | 1026 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
9b58e976 LH |
1027 | if (exceeded) |
1028 | do_start_rt_bandwidth(sched_rt_bandwidth(rt_rq)); | |
cc2991cf | 1029 | } |
354d60c2 | 1030 | } |
bb44e5d1 IM |
1031 | } |
1032 | ||
f4ebcbc0 | 1033 | static void |
5c66d1b9 | 1034 | dequeue_top_rt_rq(struct rt_rq *rt_rq, unsigned int count) |
f4ebcbc0 KT |
1035 | { |
1036 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1037 | ||
1038 | BUG_ON(&rq->rt != rt_rq); | |
1039 | ||
1040 | if (!rt_rq->rt_queued) | |
1041 | return; | |
1042 | ||
1043 | BUG_ON(!rq->nr_running); | |
1044 | ||
5c66d1b9 | 1045 | sub_nr_running(rq, count); |
f4ebcbc0 | 1046 | rt_rq->rt_queued = 0; |
8f111bc3 | 1047 | |
f4ebcbc0 KT |
1048 | } |
1049 | ||
1050 | static void | |
1051 | enqueue_top_rt_rq(struct rt_rq *rt_rq) | |
1052 | { | |
1053 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
1054 | ||
1055 | BUG_ON(&rq->rt != rt_rq); | |
1056 | ||
1057 | if (rt_rq->rt_queued) | |
1058 | return; | |
296b2ffe VG |
1059 | |
1060 | if (rt_rq_throttled(rt_rq)) | |
f4ebcbc0 KT |
1061 | return; |
1062 | ||
296b2ffe VG |
1063 | if (rt_rq->rt_nr_running) { |
1064 | add_nr_running(rq, rt_rq->rt_nr_running); | |
1065 | rt_rq->rt_queued = 1; | |
1066 | } | |
8f111bc3 PZ |
1067 | |
1068 | /* Kick cpufreq (see the comment in kernel/sched/sched.h). */ | |
1069 | cpufreq_update_util(rq, 0); | |
f4ebcbc0 KT |
1070 | } |
1071 | ||
398a153b | 1072 | #if defined CONFIG_SMP |
e864c499 | 1073 | |
398a153b GH |
1074 | static void |
1075 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 1076 | { |
4d984277 | 1077 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 1078 | |
757dfcaa KT |
1079 | #ifdef CONFIG_RT_GROUP_SCHED |
1080 | /* | |
1081 | * Change rq's cpupri only if rt_rq is the top queue. | |
1082 | */ | |
1083 | if (&rq->rt != rt_rq) | |
1084 | return; | |
1085 | #endif | |
5181f4a4 SR |
1086 | if (rq->online && prio < prev_prio) |
1087 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); | |
398a153b | 1088 | } |
73fe6aae | 1089 | |
398a153b GH |
1090 | static void |
1091 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
1092 | { | |
1093 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 1094 | |
757dfcaa KT |
1095 | #ifdef CONFIG_RT_GROUP_SCHED |
1096 | /* | |
1097 | * Change rq's cpupri only if rt_rq is the top queue. | |
1098 | */ | |
1099 | if (&rq->rt != rt_rq) | |
1100 | return; | |
1101 | #endif | |
398a153b GH |
1102 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) |
1103 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
1104 | } |
1105 | ||
398a153b GH |
1106 | #else /* CONFIG_SMP */ |
1107 | ||
6f505b16 | 1108 | static inline |
398a153b GH |
1109 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
1110 | static inline | |
1111 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
1112 | ||
1113 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 1114 | |
052f1dc7 | 1115 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
1116 | static void |
1117 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
1118 | { | |
1119 | int prev_prio = rt_rq->highest_prio.curr; | |
1120 | ||
1121 | if (prio < prev_prio) | |
1122 | rt_rq->highest_prio.curr = prio; | |
1123 | ||
1124 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
1125 | } | |
1126 | ||
1127 | static void | |
1128 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
1129 | { | |
1130 | int prev_prio = rt_rq->highest_prio.curr; | |
1131 | ||
6f505b16 | 1132 | if (rt_rq->rt_nr_running) { |
764a9d6f | 1133 | |
398a153b | 1134 | WARN_ON(prio < prev_prio); |
764a9d6f | 1135 | |
e864c499 | 1136 | /* |
398a153b GH |
1137 | * This may have been our highest task, and therefore |
1138 | * we may have some recomputation to do | |
e864c499 | 1139 | */ |
398a153b | 1140 | if (prio == prev_prio) { |
e864c499 GH |
1141 | struct rt_prio_array *array = &rt_rq->active; |
1142 | ||
1143 | rt_rq->highest_prio.curr = | |
764a9d6f | 1144 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
1145 | } |
1146 | ||
934fc331 PZ |
1147 | } else { |
1148 | rt_rq->highest_prio.curr = MAX_RT_PRIO-1; | |
1149 | } | |
73fe6aae | 1150 | |
398a153b GH |
1151 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
1152 | } | |
1f11eb6a | 1153 | |
398a153b GH |
1154 | #else |
1155 | ||
1156 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1157 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1158 | ||
1159 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 1160 | |
052f1dc7 | 1161 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
1162 | |
1163 | static void | |
1164 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1165 | { | |
1166 | if (rt_se_boosted(rt_se)) | |
1167 | rt_rq->rt_nr_boosted++; | |
1168 | ||
1169 | if (rt_rq->tg) | |
1170 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
1171 | } | |
1172 | ||
1173 | static void | |
1174 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1175 | { | |
23b0fdfc PZ |
1176 | if (rt_se_boosted(rt_se)) |
1177 | rt_rq->rt_nr_boosted--; | |
1178 | ||
1179 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
398a153b GH |
1180 | } |
1181 | ||
1182 | #else /* CONFIG_RT_GROUP_SCHED */ | |
1183 | ||
1184 | static void | |
1185 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1186 | { | |
1187 | start_rt_bandwidth(&def_rt_bandwidth); | |
1188 | } | |
1189 | ||
1190 | static inline | |
1191 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
1192 | ||
1193 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
1194 | ||
22abdef3 KT |
1195 | static inline |
1196 | unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se) | |
1197 | { | |
1198 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1199 | ||
1200 | if (group_rq) | |
1201 | return group_rq->rt_nr_running; | |
1202 | else | |
1203 | return 1; | |
1204 | } | |
1205 | ||
01d36d0a FW |
1206 | static inline |
1207 | unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se) | |
1208 | { | |
1209 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
1210 | struct task_struct *tsk; | |
1211 | ||
1212 | if (group_rq) | |
1213 | return group_rq->rr_nr_running; | |
1214 | ||
1215 | tsk = rt_task_of(rt_se); | |
1216 | ||
1217 | return (tsk->policy == SCHED_RR) ? 1 : 0; | |
1218 | } | |
1219 | ||
398a153b GH |
1220 | static inline |
1221 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1222 | { | |
1223 | int prio = rt_se_prio(rt_se); | |
1224 | ||
1225 | WARN_ON(!rt_prio(prio)); | |
22abdef3 | 1226 | rt_rq->rt_nr_running += rt_se_nr_running(rt_se); |
01d36d0a | 1227 | rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se); |
398a153b GH |
1228 | |
1229 | inc_rt_prio(rt_rq, prio); | |
398a153b GH |
1230 | inc_rt_group(rt_se, rt_rq); |
1231 | } | |
1232 | ||
1233 | static inline | |
1234 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1235 | { | |
1236 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
1237 | WARN_ON(!rt_rq->rt_nr_running); | |
22abdef3 | 1238 | rt_rq->rt_nr_running -= rt_se_nr_running(rt_se); |
01d36d0a | 1239 | rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se); |
398a153b GH |
1240 | |
1241 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
398a153b | 1242 | dec_rt_group(rt_se, rt_rq); |
63489e45 SR |
1243 | } |
1244 | ||
ff77e468 PZ |
1245 | /* |
1246 | * Change rt_se->run_list location unless SAVE && !MOVE | |
1247 | * | |
1248 | * assumes ENQUEUE/DEQUEUE flags match | |
1249 | */ | |
1250 | static inline bool move_entity(unsigned int flags) | |
1251 | { | |
1252 | if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE) | |
1253 | return false; | |
1254 | ||
1255 | return true; | |
1256 | } | |
1257 | ||
1258 | static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array) | |
1259 | { | |
1260 | list_del_init(&rt_se->run_list); | |
1261 | ||
1262 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
1263 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
1264 | ||
1265 | rt_se->on_list = 0; | |
1266 | } | |
1267 | ||
57a5c2da YS |
1268 | static inline struct sched_statistics * |
1269 | __schedstats_from_rt_se(struct sched_rt_entity *rt_se) | |
1270 | { | |
1271 | #ifdef CONFIG_RT_GROUP_SCHED | |
1272 | /* schedstats is not supported for rt group. */ | |
1273 | if (!rt_entity_is_task(rt_se)) | |
1274 | return NULL; | |
1275 | #endif | |
1276 | ||
1277 | return &rt_task_of(rt_se)->stats; | |
1278 | } | |
1279 | ||
1280 | static inline void | |
1281 | update_stats_wait_start_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) | |
1282 | { | |
1283 | struct sched_statistics *stats; | |
1284 | struct task_struct *p = NULL; | |
1285 | ||
1286 | if (!schedstat_enabled()) | |
1287 | return; | |
1288 | ||
1289 | if (rt_entity_is_task(rt_se)) | |
1290 | p = rt_task_of(rt_se); | |
1291 | ||
1292 | stats = __schedstats_from_rt_se(rt_se); | |
1293 | if (!stats) | |
1294 | return; | |
1295 | ||
1296 | __update_stats_wait_start(rq_of_rt_rq(rt_rq), p, stats); | |
1297 | } | |
1298 | ||
1299 | static inline void | |
1300 | update_stats_enqueue_sleeper_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) | |
1301 | { | |
1302 | struct sched_statistics *stats; | |
1303 | struct task_struct *p = NULL; | |
1304 | ||
1305 | if (!schedstat_enabled()) | |
1306 | return; | |
1307 | ||
1308 | if (rt_entity_is_task(rt_se)) | |
1309 | p = rt_task_of(rt_se); | |
1310 | ||
1311 | stats = __schedstats_from_rt_se(rt_se); | |
1312 | if (!stats) | |
1313 | return; | |
1314 | ||
1315 | __update_stats_enqueue_sleeper(rq_of_rt_rq(rt_rq), p, stats); | |
1316 | } | |
1317 | ||
1318 | static inline void | |
1319 | update_stats_enqueue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, | |
1320 | int flags) | |
1321 | { | |
1322 | if (!schedstat_enabled()) | |
1323 | return; | |
1324 | ||
1325 | if (flags & ENQUEUE_WAKEUP) | |
1326 | update_stats_enqueue_sleeper_rt(rt_rq, rt_se); | |
1327 | } | |
1328 | ||
1329 | static inline void | |
1330 | update_stats_wait_end_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) | |
1331 | { | |
1332 | struct sched_statistics *stats; | |
1333 | struct task_struct *p = NULL; | |
1334 | ||
1335 | if (!schedstat_enabled()) | |
1336 | return; | |
1337 | ||
1338 | if (rt_entity_is_task(rt_se)) | |
1339 | p = rt_task_of(rt_se); | |
1340 | ||
1341 | stats = __schedstats_from_rt_se(rt_se); | |
1342 | if (!stats) | |
1343 | return; | |
1344 | ||
1345 | __update_stats_wait_end(rq_of_rt_rq(rt_rq), p, stats); | |
1346 | } | |
1347 | ||
1348 | static inline void | |
1349 | update_stats_dequeue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, | |
1350 | int flags) | |
1351 | { | |
1352 | struct task_struct *p = NULL; | |
1353 | ||
1354 | if (!schedstat_enabled()) | |
1355 | return; | |
1356 | ||
1357 | if (rt_entity_is_task(rt_se)) | |
1358 | p = rt_task_of(rt_se); | |
1359 | ||
1360 | if ((flags & DEQUEUE_SLEEP) && p) { | |
1361 | unsigned int state; | |
1362 | ||
1363 | state = READ_ONCE(p->__state); | |
1364 | if (state & TASK_INTERRUPTIBLE) | |
1365 | __schedstat_set(p->stats.sleep_start, | |
1366 | rq_clock(rq_of_rt_rq(rt_rq))); | |
1367 | ||
1368 | if (state & TASK_UNINTERRUPTIBLE) | |
1369 | __schedstat_set(p->stats.block_start, | |
1370 | rq_clock(rq_of_rt_rq(rt_rq))); | |
1371 | } | |
1372 | } | |
1373 | ||
ff77e468 | 1374 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
bb44e5d1 | 1375 | { |
6f505b16 PZ |
1376 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
1377 | struct rt_prio_array *array = &rt_rq->active; | |
1378 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 1379 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 1380 | |
ad2a3f13 PZ |
1381 | /* |
1382 | * Don't enqueue the group if its throttled, or when empty. | |
1383 | * The latter is a consequence of the former when a child group | |
1384 | * get throttled and the current group doesn't have any other | |
1385 | * active members. | |
1386 | */ | |
ff77e468 PZ |
1387 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) { |
1388 | if (rt_se->on_list) | |
1389 | __delist_rt_entity(rt_se, array); | |
6f505b16 | 1390 | return; |
ff77e468 | 1391 | } |
63489e45 | 1392 | |
ff77e468 PZ |
1393 | if (move_entity(flags)) { |
1394 | WARN_ON_ONCE(rt_se->on_list); | |
1395 | if (flags & ENQUEUE_HEAD) | |
1396 | list_add(&rt_se->run_list, queue); | |
1397 | else | |
1398 | list_add_tail(&rt_se->run_list, queue); | |
1399 | ||
1400 | __set_bit(rt_se_prio(rt_se), array->bitmap); | |
1401 | rt_se->on_list = 1; | |
1402 | } | |
1403 | rt_se->on_rq = 1; | |
78f2c7db | 1404 | |
6f505b16 PZ |
1405 | inc_rt_tasks(rt_se, rt_rq); |
1406 | } | |
1407 | ||
ff77e468 | 1408 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
6f505b16 PZ |
1409 | { |
1410 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
1411 | struct rt_prio_array *array = &rt_rq->active; | |
1412 | ||
ff77e468 PZ |
1413 | if (move_entity(flags)) { |
1414 | WARN_ON_ONCE(!rt_se->on_list); | |
1415 | __delist_rt_entity(rt_se, array); | |
1416 | } | |
1417 | rt_se->on_rq = 0; | |
6f505b16 PZ |
1418 | |
1419 | dec_rt_tasks(rt_se, rt_rq); | |
1420 | } | |
1421 | ||
1422 | /* | |
1423 | * Because the prio of an upper entry depends on the lower | |
1424 | * entries, we must remove entries top - down. | |
6f505b16 | 1425 | */ |
ff77e468 | 1426 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags) |
6f505b16 | 1427 | { |
ad2a3f13 | 1428 | struct sched_rt_entity *back = NULL; |
5c66d1b9 | 1429 | unsigned int rt_nr_running; |
6f505b16 | 1430 | |
58d6c2d7 PZ |
1431 | for_each_sched_rt_entity(rt_se) { |
1432 | rt_se->back = back; | |
1433 | back = rt_se; | |
1434 | } | |
1435 | ||
5c66d1b9 | 1436 | rt_nr_running = rt_rq_of_se(back)->rt_nr_running; |
f4ebcbc0 | 1437 | |
58d6c2d7 PZ |
1438 | for (rt_se = back; rt_se; rt_se = rt_se->back) { |
1439 | if (on_rt_rq(rt_se)) | |
ff77e468 | 1440 | __dequeue_rt_entity(rt_se, flags); |
ad2a3f13 | 1441 | } |
5c66d1b9 NSJ |
1442 | |
1443 | dequeue_top_rt_rq(rt_rq_of_se(back), rt_nr_running); | |
ad2a3f13 PZ |
1444 | } |
1445 | ||
ff77e468 | 1446 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
ad2a3f13 | 1447 | { |
f4ebcbc0 KT |
1448 | struct rq *rq = rq_of_rt_se(rt_se); |
1449 | ||
57a5c2da YS |
1450 | update_stats_enqueue_rt(rt_rq_of_se(rt_se), rt_se, flags); |
1451 | ||
ff77e468 | 1452 | dequeue_rt_stack(rt_se, flags); |
ad2a3f13 | 1453 | for_each_sched_rt_entity(rt_se) |
ff77e468 | 1454 | __enqueue_rt_entity(rt_se, flags); |
f4ebcbc0 | 1455 | enqueue_top_rt_rq(&rq->rt); |
ad2a3f13 PZ |
1456 | } |
1457 | ||
ff77e468 | 1458 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) |
ad2a3f13 | 1459 | { |
f4ebcbc0 KT |
1460 | struct rq *rq = rq_of_rt_se(rt_se); |
1461 | ||
57a5c2da YS |
1462 | update_stats_dequeue_rt(rt_rq_of_se(rt_se), rt_se, flags); |
1463 | ||
ff77e468 | 1464 | dequeue_rt_stack(rt_se, flags); |
ad2a3f13 PZ |
1465 | |
1466 | for_each_sched_rt_entity(rt_se) { | |
1467 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
1468 | ||
1469 | if (rt_rq && rt_rq->rt_nr_running) | |
ff77e468 | 1470 | __enqueue_rt_entity(rt_se, flags); |
58d6c2d7 | 1471 | } |
f4ebcbc0 | 1472 | enqueue_top_rt_rq(&rq->rt); |
bb44e5d1 IM |
1473 | } |
1474 | ||
1475 | /* | |
1476 | * Adding/removing a task to/from a priority array: | |
1477 | */ | |
ea87bb78 | 1478 | static void |
371fd7e7 | 1479 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
6f505b16 PZ |
1480 | { |
1481 | struct sched_rt_entity *rt_se = &p->rt; | |
1482 | ||
371fd7e7 | 1483 | if (flags & ENQUEUE_WAKEUP) |
6f505b16 PZ |
1484 | rt_se->timeout = 0; |
1485 | ||
57a5c2da YS |
1486 | check_schedstat_required(); |
1487 | update_stats_wait_start_rt(rt_rq_of_se(rt_se), rt_se); | |
1488 | ||
ff77e468 | 1489 | enqueue_rt_entity(rt_se, flags); |
c09595f6 | 1490 | |
4b53a341 | 1491 | if (!task_current(rq, p) && p->nr_cpus_allowed > 1) |
917b627d | 1492 | enqueue_pushable_task(rq, p); |
6f505b16 PZ |
1493 | } |
1494 | ||
371fd7e7 | 1495 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1496 | { |
6f505b16 | 1497 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 1498 | |
f1e14ef6 | 1499 | update_curr_rt(rq); |
ff77e468 | 1500 | dequeue_rt_entity(rt_se, flags); |
c09595f6 | 1501 | |
917b627d | 1502 | dequeue_pushable_task(rq, p); |
bb44e5d1 IM |
1503 | } |
1504 | ||
1505 | /* | |
60686317 RW |
1506 | * Put task to the head or the end of the run list without the overhead of |
1507 | * dequeue followed by enqueue. | |
bb44e5d1 | 1508 | */ |
7ebefa8c DA |
1509 | static void |
1510 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 1511 | { |
1cdad715 | 1512 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
1513 | struct rt_prio_array *array = &rt_rq->active; |
1514 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
1515 | ||
1516 | if (head) | |
1517 | list_move(&rt_se->run_list, queue); | |
1518 | else | |
1519 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 1520 | } |
6f505b16 PZ |
1521 | } |
1522 | ||
7ebefa8c | 1523 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 1524 | { |
6f505b16 PZ |
1525 | struct sched_rt_entity *rt_se = &p->rt; |
1526 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1527 | |
6f505b16 PZ |
1528 | for_each_sched_rt_entity(rt_se) { |
1529 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 1530 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 1531 | } |
bb44e5d1 IM |
1532 | } |
1533 | ||
6f505b16 | 1534 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 1535 | { |
7ebefa8c | 1536 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
1537 | } |
1538 | ||
e7693a36 | 1539 | #ifdef CONFIG_SMP |
318e0893 GH |
1540 | static int find_lowest_rq(struct task_struct *task); |
1541 | ||
0017d735 | 1542 | static int |
3aef1551 | 1543 | select_task_rq_rt(struct task_struct *p, int cpu, int flags) |
e7693a36 | 1544 | { |
7608dec2 PZ |
1545 | struct task_struct *curr; |
1546 | struct rq *rq; | |
804d402f | 1547 | bool test; |
c37495fd SR |
1548 | |
1549 | /* For anything but wake ups, just return the task_cpu */ | |
3aef1551 | 1550 | if (!(flags & (WF_TTWU | WF_FORK))) |
c37495fd SR |
1551 | goto out; |
1552 | ||
7608dec2 PZ |
1553 | rq = cpu_rq(cpu); |
1554 | ||
1555 | rcu_read_lock(); | |
316c1608 | 1556 | curr = READ_ONCE(rq->curr); /* unlocked access */ |
7608dec2 | 1557 | |
318e0893 | 1558 | /* |
7608dec2 | 1559 | * If the current task on @p's runqueue is an RT task, then |
e1f47d89 SR |
1560 | * try to see if we can wake this RT task up on another |
1561 | * runqueue. Otherwise simply start this RT task | |
1562 | * on its current runqueue. | |
1563 | * | |
43fa5460 SR |
1564 | * We want to avoid overloading runqueues. If the woken |
1565 | * task is a higher priority, then it will stay on this CPU | |
1566 | * and the lower prio task should be moved to another CPU. | |
1567 | * Even though this will probably make the lower prio task | |
1568 | * lose its cache, we do not want to bounce a higher task | |
1569 | * around just because it gave up its CPU, perhaps for a | |
1570 | * lock? | |
1571 | * | |
1572 | * For equal prio tasks, we just let the scheduler sort it out. | |
7608dec2 PZ |
1573 | * |
1574 | * Otherwise, just let it ride on the affined RQ and the | |
1575 | * post-schedule router will push the preempted task away | |
1576 | * | |
1577 | * This test is optimistic, if we get it wrong the load-balancer | |
1578 | * will have to sort it out. | |
804d402f QY |
1579 | * |
1580 | * We take into account the capacity of the CPU to ensure it fits the | |
1581 | * requirement of the task - which is only important on heterogeneous | |
1582 | * systems like big.LITTLE. | |
318e0893 | 1583 | */ |
804d402f QY |
1584 | test = curr && |
1585 | unlikely(rt_task(curr)) && | |
1586 | (curr->nr_cpus_allowed < 2 || curr->prio <= p->prio); | |
1587 | ||
1588 | if (test || !rt_task_fits_capacity(p, cpu)) { | |
7608dec2 | 1589 | int target = find_lowest_rq(p); |
318e0893 | 1590 | |
b28bc1e0 QY |
1591 | /* |
1592 | * Bail out if we were forcing a migration to find a better | |
1593 | * fitting CPU but our search failed. | |
1594 | */ | |
1595 | if (!test && target != -1 && !rt_task_fits_capacity(p, target)) | |
1596 | goto out_unlock; | |
1597 | ||
80e3d87b TC |
1598 | /* |
1599 | * Don't bother moving it if the destination CPU is | |
1600 | * not running a lower priority task. | |
1601 | */ | |
1602 | if (target != -1 && | |
1603 | p->prio < cpu_rq(target)->rt.highest_prio.curr) | |
7608dec2 | 1604 | cpu = target; |
318e0893 | 1605 | } |
b28bc1e0 QY |
1606 | |
1607 | out_unlock: | |
7608dec2 | 1608 | rcu_read_unlock(); |
318e0893 | 1609 | |
c37495fd | 1610 | out: |
7608dec2 | 1611 | return cpu; |
e7693a36 | 1612 | } |
7ebefa8c DA |
1613 | |
1614 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1615 | { | |
308a623a WL |
1616 | /* |
1617 | * Current can't be migrated, useless to reschedule, | |
1618 | * let's hope p can move out. | |
1619 | */ | |
4b53a341 | 1620 | if (rq->curr->nr_cpus_allowed == 1 || |
a1bd02e1 | 1621 | !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) |
7ebefa8c DA |
1622 | return; |
1623 | ||
308a623a WL |
1624 | /* |
1625 | * p is migratable, so let's not schedule it and | |
1626 | * see if it is pushed or pulled somewhere else. | |
1627 | */ | |
804d402f | 1628 | if (p->nr_cpus_allowed != 1 && |
a1bd02e1 | 1629 | cpupri_find(&rq->rd->cpupri, p, NULL)) |
13b8bd0a | 1630 | return; |
24600ce8 | 1631 | |
7ebefa8c | 1632 | /* |
97fb7a0a IM |
1633 | * There appear to be other CPUs that can accept |
1634 | * the current task but none can run 'p', so lets reschedule | |
1635 | * to try and push the current task away: | |
7ebefa8c DA |
1636 | */ |
1637 | requeue_task_rt(rq, p, 1); | |
8875125e | 1638 | resched_curr(rq); |
7ebefa8c DA |
1639 | } |
1640 | ||
6e2df058 PZ |
1641 | static int balance_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf) |
1642 | { | |
1643 | if (!on_rt_rq(&p->rt) && need_pull_rt_task(rq, p)) { | |
1644 | /* | |
1645 | * This is OK, because current is on_cpu, which avoids it being | |
1646 | * picked for load-balance and preemption/IRQs are still | |
1647 | * disabled avoiding further scheduler activity on it and we've | |
1648 | * not yet started the picking loop. | |
1649 | */ | |
1650 | rq_unpin_lock(rq, rf); | |
1651 | pull_rt_task(rq); | |
1652 | rq_repin_lock(rq, rf); | |
1653 | } | |
1654 | ||
1655 | return sched_stop_runnable(rq) || sched_dl_runnable(rq) || sched_rt_runnable(rq); | |
1656 | } | |
e7693a36 GH |
1657 | #endif /* CONFIG_SMP */ |
1658 | ||
bb44e5d1 IM |
1659 | /* |
1660 | * Preempt the current task with a newly woken task if needed: | |
1661 | */ | |
e23edc86 | 1662 | static void wakeup_preempt_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1663 | { |
45c01e82 | 1664 | if (p->prio < rq->curr->prio) { |
8875125e | 1665 | resched_curr(rq); |
45c01e82 GH |
1666 | return; |
1667 | } | |
1668 | ||
1669 | #ifdef CONFIG_SMP | |
1670 | /* | |
1671 | * If: | |
1672 | * | |
1673 | * - the newly woken task is of equal priority to the current task | |
1674 | * - the newly woken task is non-migratable while current is migratable | |
1675 | * - current will be preempted on the next reschedule | |
1676 | * | |
1677 | * we should check to see if current can readily move to a different | |
1678 | * cpu. If so, we will reschedule to allow the push logic to try | |
1679 | * to move current somewhere else, making room for our non-migratable | |
1680 | * task. | |
1681 | */ | |
8dd0de8b | 1682 | if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) |
7ebefa8c | 1683 | check_preempt_equal_prio(rq, p); |
45c01e82 | 1684 | #endif |
bb44e5d1 IM |
1685 | } |
1686 | ||
a0e813f2 | 1687 | static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool first) |
ff1cdc94 | 1688 | { |
57a5c2da YS |
1689 | struct sched_rt_entity *rt_se = &p->rt; |
1690 | struct rt_rq *rt_rq = &rq->rt; | |
1691 | ||
ff1cdc94 | 1692 | p->se.exec_start = rq_clock_task(rq); |
57a5c2da YS |
1693 | if (on_rt_rq(&p->rt)) |
1694 | update_stats_wait_end_rt(rt_rq, rt_se); | |
ff1cdc94 MS |
1695 | |
1696 | /* The running task is never eligible for pushing */ | |
1697 | dequeue_pushable_task(rq, p); | |
f95d4eae | 1698 | |
a0e813f2 PZ |
1699 | if (!first) |
1700 | return; | |
1701 | ||
f95d4eae PZ |
1702 | /* |
1703 | * If prev task was rt, put_prev_task() has already updated the | |
1704 | * utilization. We only care of the case where we start to schedule a | |
1705 | * rt task | |
1706 | */ | |
1707 | if (rq->curr->sched_class != &rt_sched_class) | |
1708 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); | |
1709 | ||
1710 | rt_queue_push_tasks(rq); | |
ff1cdc94 MS |
1711 | } |
1712 | ||
821aecd0 | 1713 | static struct sched_rt_entity *pick_next_rt_entity(struct rt_rq *rt_rq) |
bb44e5d1 | 1714 | { |
6f505b16 PZ |
1715 | struct rt_prio_array *array = &rt_rq->active; |
1716 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1717 | struct list_head *queue; |
1718 | int idx; | |
1719 | ||
1720 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1721 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1722 | |
1723 | queue = array->queue + idx; | |
7c4a5b89 PB |
1724 | if (SCHED_WARN_ON(list_empty(queue))) |
1725 | return NULL; | |
6f505b16 | 1726 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1727 | |
6f505b16 PZ |
1728 | return next; |
1729 | } | |
bb44e5d1 | 1730 | |
917b627d | 1731 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1732 | { |
1733 | struct sched_rt_entity *rt_se; | |
606dba2e | 1734 | struct rt_rq *rt_rq = &rq->rt; |
6f505b16 PZ |
1735 | |
1736 | do { | |
821aecd0 | 1737 | rt_se = pick_next_rt_entity(rt_rq); |
7c4a5b89 PB |
1738 | if (unlikely(!rt_se)) |
1739 | return NULL; | |
6f505b16 PZ |
1740 | rt_rq = group_rt_rq(rt_se); |
1741 | } while (rt_rq); | |
1742 | ||
ff1cdc94 | 1743 | return rt_task_of(rt_se); |
917b627d GH |
1744 | } |
1745 | ||
21f56ffe | 1746 | static struct task_struct *pick_task_rt(struct rq *rq) |
917b627d | 1747 | { |
606dba2e | 1748 | struct task_struct *p; |
606dba2e | 1749 | |
6e2df058 | 1750 | if (!sched_rt_runnable(rq)) |
606dba2e PZ |
1751 | return NULL; |
1752 | ||
606dba2e | 1753 | p = _pick_next_task_rt(rq); |
21f56ffe PZ |
1754 | |
1755 | return p; | |
1756 | } | |
1757 | ||
1758 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
1759 | { | |
1760 | struct task_struct *p = pick_task_rt(rq); | |
1761 | ||
1762 | if (p) | |
1763 | set_next_task_rt(rq, p, true); | |
1764 | ||
6f505b16 | 1765 | return p; |
bb44e5d1 IM |
1766 | } |
1767 | ||
6e2df058 | 1768 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1769 | { |
57a5c2da YS |
1770 | struct sched_rt_entity *rt_se = &p->rt; |
1771 | struct rt_rq *rt_rq = &rq->rt; | |
1772 | ||
1773 | if (on_rt_rq(&p->rt)) | |
1774 | update_stats_wait_start_rt(rt_rq, rt_se); | |
1775 | ||
f1e14ef6 | 1776 | update_curr_rt(rq); |
917b627d | 1777 | |
23127296 | 1778 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); |
371bf427 | 1779 | |
917b627d GH |
1780 | /* |
1781 | * The previous task needs to be made eligible for pushing | |
1782 | * if it is still active | |
1783 | */ | |
4b53a341 | 1784 | if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1) |
917b627d | 1785 | enqueue_pushable_task(rq, p); |
bb44e5d1 IM |
1786 | } |
1787 | ||
681f3e68 | 1788 | #ifdef CONFIG_SMP |
6f505b16 | 1789 | |
e8fa1362 SR |
1790 | /* Only try algorithms three times */ |
1791 | #define RT_MAX_TRIES 3 | |
1792 | ||
f65eda4f SR |
1793 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1794 | { | |
0b9d46fc | 1795 | if (!task_on_cpu(rq, p) && |
95158a89 | 1796 | cpumask_test_cpu(cpu, &p->cpus_mask)) |
f65eda4f | 1797 | return 1; |
97fb7a0a | 1798 | |
f65eda4f SR |
1799 | return 0; |
1800 | } | |
1801 | ||
e23ee747 KT |
1802 | /* |
1803 | * Return the highest pushable rq's task, which is suitable to be executed | |
97fb7a0a | 1804 | * on the CPU, NULL otherwise |
e23ee747 KT |
1805 | */ |
1806 | static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu) | |
e8fa1362 | 1807 | { |
e23ee747 KT |
1808 | struct plist_head *head = &rq->rt.pushable_tasks; |
1809 | struct task_struct *p; | |
3d07467b | 1810 | |
e23ee747 KT |
1811 | if (!has_pushable_tasks(rq)) |
1812 | return NULL; | |
3d07467b | 1813 | |
e23ee747 KT |
1814 | plist_for_each_entry(p, head, pushable_tasks) { |
1815 | if (pick_rt_task(rq, p, cpu)) | |
1816 | return p; | |
f65eda4f SR |
1817 | } |
1818 | ||
e23ee747 | 1819 | return NULL; |
e8fa1362 SR |
1820 | } |
1821 | ||
0e3900e6 | 1822 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1823 | |
6e1254d2 GH |
1824 | static int find_lowest_rq(struct task_struct *task) |
1825 | { | |
1826 | struct sched_domain *sd; | |
4ba29684 | 1827 | struct cpumask *lowest_mask = this_cpu_cpumask_var_ptr(local_cpu_mask); |
6e1254d2 GH |
1828 | int this_cpu = smp_processor_id(); |
1829 | int cpu = task_cpu(task); | |
a1bd02e1 | 1830 | int ret; |
06f90dbd | 1831 | |
0da938c4 SR |
1832 | /* Make sure the mask is initialized first */ |
1833 | if (unlikely(!lowest_mask)) | |
1834 | return -1; | |
1835 | ||
4b53a341 | 1836 | if (task->nr_cpus_allowed == 1) |
6e0534f2 | 1837 | return -1; /* No other targets possible */ |
6e1254d2 | 1838 | |
a1bd02e1 QY |
1839 | /* |
1840 | * If we're on asym system ensure we consider the different capacities | |
1841 | * of the CPUs when searching for the lowest_mask. | |
1842 | */ | |
740cf8a7 | 1843 | if (sched_asym_cpucap_active()) { |
a1bd02e1 QY |
1844 | |
1845 | ret = cpupri_find_fitness(&task_rq(task)->rd->cpupri, | |
1846 | task, lowest_mask, | |
1847 | rt_task_fits_capacity); | |
1848 | } else { | |
1849 | ||
1850 | ret = cpupri_find(&task_rq(task)->rd->cpupri, | |
1851 | task, lowest_mask); | |
1852 | } | |
1853 | ||
1854 | if (!ret) | |
6e0534f2 | 1855 | return -1; /* No targets found */ |
6e1254d2 GH |
1856 | |
1857 | /* | |
97fb7a0a | 1858 | * At this point we have built a mask of CPUs representing the |
6e1254d2 GH |
1859 | * lowest priority tasks in the system. Now we want to elect |
1860 | * the best one based on our affinity and topology. | |
1861 | * | |
97fb7a0a | 1862 | * We prioritize the last CPU that the task executed on since |
6e1254d2 GH |
1863 | * it is most likely cache-hot in that location. |
1864 | */ | |
96f874e2 | 1865 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1866 | return cpu; |
1867 | ||
1868 | /* | |
1869 | * Otherwise, we consult the sched_domains span maps to figure | |
97fb7a0a | 1870 | * out which CPU is logically closest to our hot cache data. |
6e1254d2 | 1871 | */ |
e2c88063 RR |
1872 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) |
1873 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
6e1254d2 | 1874 | |
cd4ae6ad | 1875 | rcu_read_lock(); |
e2c88063 RR |
1876 | for_each_domain(cpu, sd) { |
1877 | if (sd->flags & SD_WAKE_AFFINE) { | |
1878 | int best_cpu; | |
6e1254d2 | 1879 | |
e2c88063 RR |
1880 | /* |
1881 | * "this_cpu" is cheaper to preempt than a | |
1882 | * remote processor. | |
1883 | */ | |
1884 | if (this_cpu != -1 && | |
cd4ae6ad XF |
1885 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { |
1886 | rcu_read_unlock(); | |
e2c88063 | 1887 | return this_cpu; |
cd4ae6ad | 1888 | } |
e2c88063 | 1889 | |
14e292f8 PZ |
1890 | best_cpu = cpumask_any_and_distribute(lowest_mask, |
1891 | sched_domain_span(sd)); | |
cd4ae6ad XF |
1892 | if (best_cpu < nr_cpu_ids) { |
1893 | rcu_read_unlock(); | |
e2c88063 | 1894 | return best_cpu; |
cd4ae6ad | 1895 | } |
6e1254d2 GH |
1896 | } |
1897 | } | |
cd4ae6ad | 1898 | rcu_read_unlock(); |
6e1254d2 GH |
1899 | |
1900 | /* | |
1901 | * And finally, if there were no matches within the domains | |
1902 | * just give the caller *something* to work with from the compatible | |
1903 | * locations. | |
1904 | */ | |
e2c88063 RR |
1905 | if (this_cpu != -1) |
1906 | return this_cpu; | |
1907 | ||
14e292f8 | 1908 | cpu = cpumask_any_distribute(lowest_mask); |
e2c88063 RR |
1909 | if (cpu < nr_cpu_ids) |
1910 | return cpu; | |
97fb7a0a | 1911 | |
e2c88063 | 1912 | return -1; |
07b4032c GH |
1913 | } |
1914 | ||
1915 | /* Will lock the rq it finds */ | |
4df64c0b | 1916 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1917 | { |
1918 | struct rq *lowest_rq = NULL; | |
07b4032c | 1919 | int tries; |
4df64c0b | 1920 | int cpu; |
e8fa1362 | 1921 | |
07b4032c GH |
1922 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1923 | cpu = find_lowest_rq(task); | |
1924 | ||
2de0b463 | 1925 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1926 | break; |
1927 | ||
07b4032c GH |
1928 | lowest_rq = cpu_rq(cpu); |
1929 | ||
80e3d87b TC |
1930 | if (lowest_rq->rt.highest_prio.curr <= task->prio) { |
1931 | /* | |
1932 | * Target rq has tasks of equal or higher priority, | |
1933 | * retrying does not release any lock and is unlikely | |
1934 | * to yield a different result. | |
1935 | */ | |
1936 | lowest_rq = NULL; | |
1937 | break; | |
1938 | } | |
1939 | ||
e8fa1362 | 1940 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1941 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1942 | /* |
1943 | * We had to unlock the run queue. In | |
1944 | * the mean time, task could have | |
1945 | * migrated already or had its affinity changed. | |
1946 | * Also make sure that it wasn't scheduled on its rq. | |
feffe5bb SS |
1947 | * It is possible the task was scheduled, set |
1948 | * "migrate_disabled" and then got preempted, so we must | |
1949 | * check the task migration disable flag here too. | |
e8fa1362 | 1950 | */ |
07b4032c | 1951 | if (unlikely(task_rq(task) != rq || |
95158a89 | 1952 | !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_mask) || |
0b9d46fc | 1953 | task_on_cpu(rq, task) || |
13b5ab02 | 1954 | !rt_task(task) || |
feffe5bb | 1955 | is_migration_disabled(task) || |
da0c1e65 | 1956 | !task_on_rq_queued(task))) { |
4df64c0b | 1957 | |
7f1b4393 | 1958 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1959 | lowest_rq = NULL; |
1960 | break; | |
1961 | } | |
1962 | } | |
1963 | ||
1964 | /* If this rq is still suitable use it. */ | |
e864c499 | 1965 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1966 | break; |
1967 | ||
1968 | /* try again */ | |
1b12bbc7 | 1969 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1970 | lowest_rq = NULL; |
1971 | } | |
1972 | ||
1973 | return lowest_rq; | |
1974 | } | |
1975 | ||
917b627d GH |
1976 | static struct task_struct *pick_next_pushable_task(struct rq *rq) |
1977 | { | |
1978 | struct task_struct *p; | |
1979 | ||
1980 | if (!has_pushable_tasks(rq)) | |
1981 | return NULL; | |
1982 | ||
1983 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1984 | struct task_struct, pushable_tasks); | |
1985 | ||
1986 | BUG_ON(rq->cpu != task_cpu(p)); | |
1987 | BUG_ON(task_current(rq, p)); | |
4b53a341 | 1988 | BUG_ON(p->nr_cpus_allowed <= 1); |
917b627d | 1989 | |
da0c1e65 | 1990 | BUG_ON(!task_on_rq_queued(p)); |
917b627d GH |
1991 | BUG_ON(!rt_task(p)); |
1992 | ||
1993 | return p; | |
1994 | } | |
1995 | ||
e8fa1362 SR |
1996 | /* |
1997 | * If the current CPU has more than one RT task, see if the non | |
1998 | * running task can migrate over to a CPU that is running a task | |
1999 | * of lesser priority. | |
2000 | */ | |
a7c81556 | 2001 | static int push_rt_task(struct rq *rq, bool pull) |
e8fa1362 SR |
2002 | { |
2003 | struct task_struct *next_task; | |
2004 | struct rq *lowest_rq; | |
311e800e | 2005 | int ret = 0; |
e8fa1362 | 2006 | |
a22d7fc1 GH |
2007 | if (!rq->rt.overloaded) |
2008 | return 0; | |
2009 | ||
917b627d | 2010 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
2011 | if (!next_task) |
2012 | return 0; | |
2013 | ||
49246274 | 2014 | retry: |
49bef33e VS |
2015 | /* |
2016 | * It's possible that the next_task slipped in of | |
2017 | * higher priority than current. If that's the case | |
2018 | * just reschedule current. | |
2019 | */ | |
2020 | if (unlikely(next_task->prio < rq->curr->prio)) { | |
2021 | resched_curr(rq); | |
2022 | return 0; | |
2023 | } | |
2024 | ||
a7c81556 PZ |
2025 | if (is_migration_disabled(next_task)) { |
2026 | struct task_struct *push_task = NULL; | |
2027 | int cpu; | |
2028 | ||
2029 | if (!pull || rq->push_busy) | |
2030 | return 0; | |
2031 | ||
49bef33e VS |
2032 | /* |
2033 | * Invoking find_lowest_rq() on anything but an RT task doesn't | |
2034 | * make sense. Per the above priority check, curr has to | |
2035 | * be of higher priority than next_task, so no need to | |
2036 | * reschedule when bailing out. | |
2037 | * | |
2038 | * Note that the stoppers are masqueraded as SCHED_FIFO | |
2039 | * (cf. sched_set_stop_task()), so we can't rely on rt_task(). | |
2040 | */ | |
2041 | if (rq->curr->sched_class != &rt_sched_class) | |
2042 | return 0; | |
2043 | ||
a7c81556 PZ |
2044 | cpu = find_lowest_rq(rq->curr); |
2045 | if (cpu == -1 || cpu == rq->cpu) | |
2046 | return 0; | |
2047 | ||
2048 | /* | |
2049 | * Given we found a CPU with lower priority than @next_task, | |
2050 | * therefore it should be running. However we cannot migrate it | |
2051 | * to this other CPU, instead attempt to push the current | |
2052 | * running task on this CPU away. | |
2053 | */ | |
2054 | push_task = get_push_task(rq); | |
2055 | if (push_task) { | |
f0498d2a | 2056 | preempt_disable(); |
5cb9eaa3 | 2057 | raw_spin_rq_unlock(rq); |
a7c81556 PZ |
2058 | stop_one_cpu_nowait(rq->cpu, push_cpu_stop, |
2059 | push_task, &rq->push_work); | |
f0498d2a | 2060 | preempt_enable(); |
5cb9eaa3 | 2061 | raw_spin_rq_lock(rq); |
a7c81556 PZ |
2062 | } |
2063 | ||
2064 | return 0; | |
2065 | } | |
2066 | ||
9ebc6053 | 2067 | if (WARN_ON(next_task == rq->curr)) |
e8fa1362 SR |
2068 | return 0; |
2069 | ||
697f0a48 | 2070 | /* We might release rq lock */ |
e8fa1362 SR |
2071 | get_task_struct(next_task); |
2072 | ||
2073 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 2074 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
2075 | if (!lowest_rq) { |
2076 | struct task_struct *task; | |
2077 | /* | |
311e800e | 2078 | * find_lock_lowest_rq releases rq->lock |
1563513d GH |
2079 | * so it is possible that next_task has migrated. |
2080 | * | |
2081 | * We need to make sure that the task is still on the same | |
2082 | * run-queue and is also still the next task eligible for | |
2083 | * pushing. | |
e8fa1362 | 2084 | */ |
917b627d | 2085 | task = pick_next_pushable_task(rq); |
de16b91e | 2086 | if (task == next_task) { |
1563513d | 2087 | /* |
311e800e HD |
2088 | * The task hasn't migrated, and is still the next |
2089 | * eligible task, but we failed to find a run-queue | |
2090 | * to push it to. Do not retry in this case, since | |
97fb7a0a | 2091 | * other CPUs will pull from us when ready. |
1563513d | 2092 | */ |
1563513d | 2093 | goto out; |
e8fa1362 | 2094 | } |
917b627d | 2095 | |
1563513d GH |
2096 | if (!task) |
2097 | /* No more tasks, just exit */ | |
2098 | goto out; | |
2099 | ||
917b627d | 2100 | /* |
1563513d | 2101 | * Something has shifted, try again. |
917b627d | 2102 | */ |
1563513d GH |
2103 | put_task_struct(next_task); |
2104 | next_task = task; | |
2105 | goto retry; | |
e8fa1362 SR |
2106 | } |
2107 | ||
697f0a48 | 2108 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
2109 | set_task_cpu(next_task, lowest_rq->cpu); |
2110 | activate_task(lowest_rq, next_task, 0); | |
8875125e | 2111 | resched_curr(lowest_rq); |
a7c81556 | 2112 | ret = 1; |
e8fa1362 | 2113 | |
1b12bbc7 | 2114 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
2115 | out: |
2116 | put_task_struct(next_task); | |
2117 | ||
311e800e | 2118 | return ret; |
e8fa1362 SR |
2119 | } |
2120 | ||
e8fa1362 SR |
2121 | static void push_rt_tasks(struct rq *rq) |
2122 | { | |
2123 | /* push_rt_task will return true if it moved an RT */ | |
a7c81556 | 2124 | while (push_rt_task(rq, false)) |
e8fa1362 SR |
2125 | ; |
2126 | } | |
2127 | ||
b6366f04 | 2128 | #ifdef HAVE_RT_PUSH_IPI |
4bdced5c | 2129 | |
b6366f04 | 2130 | /* |
4bdced5c SRRH |
2131 | * When a high priority task schedules out from a CPU and a lower priority |
2132 | * task is scheduled in, a check is made to see if there's any RT tasks | |
2133 | * on other CPUs that are waiting to run because a higher priority RT task | |
2134 | * is currently running on its CPU. In this case, the CPU with multiple RT | |
2135 | * tasks queued on it (overloaded) needs to be notified that a CPU has opened | |
2136 | * up that may be able to run one of its non-running queued RT tasks. | |
2137 | * | |
2138 | * All CPUs with overloaded RT tasks need to be notified as there is currently | |
2139 | * no way to know which of these CPUs have the highest priority task waiting | |
2140 | * to run. Instead of trying to take a spinlock on each of these CPUs, | |
2141 | * which has shown to cause large latency when done on machines with many | |
2142 | * CPUs, sending an IPI to the CPUs to have them push off the overloaded | |
2143 | * RT tasks waiting to run. | |
2144 | * | |
2145 | * Just sending an IPI to each of the CPUs is also an issue, as on large | |
2146 | * count CPU machines, this can cause an IPI storm on a CPU, especially | |
2147 | * if its the only CPU with multiple RT tasks queued, and a large number | |
2148 | * of CPUs scheduling a lower priority task at the same time. | |
2149 | * | |
2150 | * Each root domain has its own irq work function that can iterate over | |
2151 | * all CPUs with RT overloaded tasks. Since all CPUs with overloaded RT | |
3b03706f | 2152 | * task must be checked if there's one or many CPUs that are lowering |
4bdced5c SRRH |
2153 | * their priority, there's a single irq work iterator that will try to |
2154 | * push off RT tasks that are waiting to run. | |
2155 | * | |
2156 | * When a CPU schedules a lower priority task, it will kick off the | |
2157 | * irq work iterator that will jump to each CPU with overloaded RT tasks. | |
2158 | * As it only takes the first CPU that schedules a lower priority task | |
2159 | * to start the process, the rto_start variable is incremented and if | |
2160 | * the atomic result is one, then that CPU will try to take the rto_lock. | |
2161 | * This prevents high contention on the lock as the process handles all | |
2162 | * CPUs scheduling lower priority tasks. | |
2163 | * | |
2164 | * All CPUs that are scheduling a lower priority task will increment the | |
2165 | * rt_loop_next variable. This will make sure that the irq work iterator | |
2166 | * checks all RT overloaded CPUs whenever a CPU schedules a new lower | |
2167 | * priority task, even if the iterator is in the middle of a scan. Incrementing | |
2168 | * the rt_loop_next will cause the iterator to perform another scan. | |
b6366f04 | 2169 | * |
b6366f04 | 2170 | */ |
ad0f1d9d | 2171 | static int rto_next_cpu(struct root_domain *rd) |
b6366f04 | 2172 | { |
4bdced5c | 2173 | int next; |
b6366f04 SR |
2174 | int cpu; |
2175 | ||
b6366f04 | 2176 | /* |
4bdced5c SRRH |
2177 | * When starting the IPI RT pushing, the rto_cpu is set to -1, |
2178 | * rt_next_cpu() will simply return the first CPU found in | |
2179 | * the rto_mask. | |
2180 | * | |
97fb7a0a | 2181 | * If rto_next_cpu() is called with rto_cpu is a valid CPU, it |
4bdced5c SRRH |
2182 | * will return the next CPU found in the rto_mask. |
2183 | * | |
2184 | * If there are no more CPUs left in the rto_mask, then a check is made | |
2185 | * against rto_loop and rto_loop_next. rto_loop is only updated with | |
2186 | * the rto_lock held, but any CPU may increment the rto_loop_next | |
2187 | * without any locking. | |
b6366f04 | 2188 | */ |
4bdced5c | 2189 | for (;;) { |
b6366f04 | 2190 | |
4bdced5c SRRH |
2191 | /* When rto_cpu is -1 this acts like cpumask_first() */ |
2192 | cpu = cpumask_next(rd->rto_cpu, rd->rto_mask); | |
b6366f04 | 2193 | |
4bdced5c | 2194 | rd->rto_cpu = cpu; |
b6366f04 | 2195 | |
4bdced5c SRRH |
2196 | if (cpu < nr_cpu_ids) |
2197 | return cpu; | |
b6366f04 | 2198 | |
4bdced5c SRRH |
2199 | rd->rto_cpu = -1; |
2200 | ||
2201 | /* | |
2202 | * ACQUIRE ensures we see the @rto_mask changes | |
2203 | * made prior to the @next value observed. | |
2204 | * | |
2205 | * Matches WMB in rt_set_overload(). | |
2206 | */ | |
2207 | next = atomic_read_acquire(&rd->rto_loop_next); | |
b6366f04 | 2208 | |
4bdced5c | 2209 | if (rd->rto_loop == next) |
b6366f04 | 2210 | break; |
4bdced5c SRRH |
2211 | |
2212 | rd->rto_loop = next; | |
b6366f04 SR |
2213 | } |
2214 | ||
4bdced5c | 2215 | return -1; |
b6366f04 SR |
2216 | } |
2217 | ||
4bdced5c SRRH |
2218 | static inline bool rto_start_trylock(atomic_t *v) |
2219 | { | |
2220 | return !atomic_cmpxchg_acquire(v, 0, 1); | |
2221 | } | |
b6366f04 | 2222 | |
4bdced5c | 2223 | static inline void rto_start_unlock(atomic_t *v) |
b6366f04 | 2224 | { |
4bdced5c SRRH |
2225 | atomic_set_release(v, 0); |
2226 | } | |
b6366f04 | 2227 | |
4bdced5c SRRH |
2228 | static void tell_cpu_to_push(struct rq *rq) |
2229 | { | |
2230 | int cpu = -1; | |
b6366f04 | 2231 | |
4bdced5c SRRH |
2232 | /* Keep the loop going if the IPI is currently active */ |
2233 | atomic_inc(&rq->rd->rto_loop_next); | |
b6366f04 | 2234 | |
4bdced5c SRRH |
2235 | /* Only one CPU can initiate a loop at a time */ |
2236 | if (!rto_start_trylock(&rq->rd->rto_loop_start)) | |
b6366f04 SR |
2237 | return; |
2238 | ||
4bdced5c | 2239 | raw_spin_lock(&rq->rd->rto_lock); |
b6366f04 | 2240 | |
4bdced5c | 2241 | /* |
97fb7a0a | 2242 | * The rto_cpu is updated under the lock, if it has a valid CPU |
4bdced5c SRRH |
2243 | * then the IPI is still running and will continue due to the |
2244 | * update to loop_next, and nothing needs to be done here. | |
2245 | * Otherwise it is finishing up and an ipi needs to be sent. | |
2246 | */ | |
2247 | if (rq->rd->rto_cpu < 0) | |
ad0f1d9d | 2248 | cpu = rto_next_cpu(rq->rd); |
4bdced5c SRRH |
2249 | |
2250 | raw_spin_unlock(&rq->rd->rto_lock); | |
2251 | ||
2252 | rto_start_unlock(&rq->rd->rto_loop_start); | |
2253 | ||
364f5665 SRV |
2254 | if (cpu >= 0) { |
2255 | /* Make sure the rd does not get freed while pushing */ | |
2256 | sched_get_rd(rq->rd); | |
4bdced5c | 2257 | irq_work_queue_on(&rq->rd->rto_push_work, cpu); |
364f5665 | 2258 | } |
b6366f04 SR |
2259 | } |
2260 | ||
2261 | /* Called from hardirq context */ | |
4bdced5c | 2262 | void rto_push_irq_work_func(struct irq_work *work) |
b6366f04 | 2263 | { |
ad0f1d9d SRV |
2264 | struct root_domain *rd = |
2265 | container_of(work, struct root_domain, rto_push_work); | |
4bdced5c | 2266 | struct rq *rq; |
b6366f04 SR |
2267 | int cpu; |
2268 | ||
4bdced5c | 2269 | rq = this_rq(); |
b6366f04 | 2270 | |
4bdced5c SRRH |
2271 | /* |
2272 | * We do not need to grab the lock to check for has_pushable_tasks. | |
2273 | * When it gets updated, a check is made if a push is possible. | |
2274 | */ | |
b6366f04 | 2275 | if (has_pushable_tasks(rq)) { |
5cb9eaa3 | 2276 | raw_spin_rq_lock(rq); |
a7c81556 PZ |
2277 | while (push_rt_task(rq, true)) |
2278 | ; | |
5cb9eaa3 | 2279 | raw_spin_rq_unlock(rq); |
b6366f04 SR |
2280 | } |
2281 | ||
ad0f1d9d | 2282 | raw_spin_lock(&rd->rto_lock); |
b6366f04 | 2283 | |
4bdced5c | 2284 | /* Pass the IPI to the next rt overloaded queue */ |
ad0f1d9d | 2285 | cpu = rto_next_cpu(rd); |
b6366f04 | 2286 | |
ad0f1d9d | 2287 | raw_spin_unlock(&rd->rto_lock); |
b6366f04 | 2288 | |
364f5665 SRV |
2289 | if (cpu < 0) { |
2290 | sched_put_rd(rd); | |
b6366f04 | 2291 | return; |
364f5665 | 2292 | } |
b6366f04 | 2293 | |
b6366f04 | 2294 | /* Try the next RT overloaded CPU */ |
ad0f1d9d | 2295 | irq_work_queue_on(&rd->rto_push_work, cpu); |
b6366f04 SR |
2296 | } |
2297 | #endif /* HAVE_RT_PUSH_IPI */ | |
2298 | ||
8046d680 | 2299 | static void pull_rt_task(struct rq *this_rq) |
f65eda4f | 2300 | { |
8046d680 PZ |
2301 | int this_cpu = this_rq->cpu, cpu; |
2302 | bool resched = false; | |
a7c81556 | 2303 | struct task_struct *p, *push_task; |
f65eda4f | 2304 | struct rq *src_rq; |
f73c52a5 | 2305 | int rt_overload_count = rt_overloaded(this_rq); |
f65eda4f | 2306 | |
f73c52a5 | 2307 | if (likely(!rt_overload_count)) |
8046d680 | 2308 | return; |
f65eda4f | 2309 | |
7c3f2ab7 PZ |
2310 | /* |
2311 | * Match the barrier from rt_set_overloaded; this guarantees that if we | |
2312 | * see overloaded we must also see the rto_mask bit. | |
2313 | */ | |
2314 | smp_rmb(); | |
2315 | ||
f73c52a5 SR |
2316 | /* If we are the only overloaded CPU do nothing */ |
2317 | if (rt_overload_count == 1 && | |
2318 | cpumask_test_cpu(this_rq->cpu, this_rq->rd->rto_mask)) | |
2319 | return; | |
2320 | ||
b6366f04 SR |
2321 | #ifdef HAVE_RT_PUSH_IPI |
2322 | if (sched_feat(RT_PUSH_IPI)) { | |
2323 | tell_cpu_to_push(this_rq); | |
8046d680 | 2324 | return; |
b6366f04 SR |
2325 | } |
2326 | #endif | |
2327 | ||
c6c4927b | 2328 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
2329 | if (this_cpu == cpu) |
2330 | continue; | |
2331 | ||
2332 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
2333 | |
2334 | /* | |
2335 | * Don't bother taking the src_rq->lock if the next highest | |
2336 | * task is known to be lower-priority than our current task. | |
2337 | * This may look racy, but if this value is about to go | |
2338 | * logically higher, the src_rq will push this task away. | |
2339 | * And if its going logically lower, we do not care | |
2340 | */ | |
2341 | if (src_rq->rt.highest_prio.next >= | |
2342 | this_rq->rt.highest_prio.curr) | |
2343 | continue; | |
2344 | ||
f65eda4f SR |
2345 | /* |
2346 | * We can potentially drop this_rq's lock in | |
2347 | * double_lock_balance, and another CPU could | |
a8728944 | 2348 | * alter this_rq |
f65eda4f | 2349 | */ |
a7c81556 | 2350 | push_task = NULL; |
a8728944 | 2351 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
2352 | |
2353 | /* | |
e23ee747 KT |
2354 | * We can pull only a task, which is pushable |
2355 | * on its rq, and no others. | |
f65eda4f | 2356 | */ |
e23ee747 | 2357 | p = pick_highest_pushable_task(src_rq, this_cpu); |
f65eda4f SR |
2358 | |
2359 | /* | |
2360 | * Do we have an RT task that preempts | |
2361 | * the to-be-scheduled task? | |
2362 | */ | |
a8728944 | 2363 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f | 2364 | WARN_ON(p == src_rq->curr); |
da0c1e65 | 2365 | WARN_ON(!task_on_rq_queued(p)); |
f65eda4f SR |
2366 | |
2367 | /* | |
2368 | * There's a chance that p is higher in priority | |
97fb7a0a | 2369 | * than what's currently running on its CPU. |
3b03706f | 2370 | * This is just that p is waking up and hasn't |
f65eda4f SR |
2371 | * had a chance to schedule. We only pull |
2372 | * p if it is lower in priority than the | |
a8728944 | 2373 | * current task on the run queue |
f65eda4f | 2374 | */ |
a8728944 | 2375 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 2376 | goto skip; |
f65eda4f | 2377 | |
a7c81556 PZ |
2378 | if (is_migration_disabled(p)) { |
2379 | push_task = get_push_task(src_rq); | |
2380 | } else { | |
2381 | deactivate_task(src_rq, p, 0); | |
2382 | set_task_cpu(p, this_cpu); | |
2383 | activate_task(this_rq, p, 0); | |
2384 | resched = true; | |
2385 | } | |
f65eda4f SR |
2386 | /* |
2387 | * We continue with the search, just in | |
2388 | * case there's an even higher prio task | |
25985edc | 2389 | * in another runqueue. (low likelihood |
f65eda4f | 2390 | * but possible) |
f65eda4f | 2391 | */ |
f65eda4f | 2392 | } |
49246274 | 2393 | skip: |
1b12bbc7 | 2394 | double_unlock_balance(this_rq, src_rq); |
a7c81556 PZ |
2395 | |
2396 | if (push_task) { | |
f0498d2a | 2397 | preempt_disable(); |
5cb9eaa3 | 2398 | raw_spin_rq_unlock(this_rq); |
a7c81556 PZ |
2399 | stop_one_cpu_nowait(src_rq->cpu, push_cpu_stop, |
2400 | push_task, &src_rq->push_work); | |
f0498d2a | 2401 | preempt_enable(); |
5cb9eaa3 | 2402 | raw_spin_rq_lock(this_rq); |
a7c81556 | 2403 | } |
f65eda4f SR |
2404 | } |
2405 | ||
8046d680 PZ |
2406 | if (resched) |
2407 | resched_curr(this_rq); | |
f65eda4f SR |
2408 | } |
2409 | ||
8ae121ac GH |
2410 | /* |
2411 | * If we are not running and we are not going to reschedule soon, we should | |
2412 | * try to push tasks away now | |
2413 | */ | |
efbbd05a | 2414 | static void task_woken_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 2415 | { |
0b9d46fc | 2416 | bool need_to_push = !task_on_cpu(rq, p) && |
804d402f QY |
2417 | !test_tsk_need_resched(rq->curr) && |
2418 | p->nr_cpus_allowed > 1 && | |
2419 | (dl_task(rq->curr) || rt_task(rq->curr)) && | |
2420 | (rq->curr->nr_cpus_allowed < 2 || | |
2421 | rq->curr->prio <= p->prio); | |
2422 | ||
d94a9df4 | 2423 | if (need_to_push) |
4642dafd SR |
2424 | push_rt_tasks(rq); |
2425 | } | |
2426 | ||
bdd7c81b | 2427 | /* Assumes rq->lock is held */ |
1f11eb6a | 2428 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
2429 | { |
2430 | if (rq->rt.overloaded) | |
2431 | rt_set_overload(rq); | |
6e0534f2 | 2432 | |
7def2be1 PZ |
2433 | __enable_runtime(rq); |
2434 | ||
e864c499 | 2435 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
2436 | } |
2437 | ||
2438 | /* Assumes rq->lock is held */ | |
1f11eb6a | 2439 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
2440 | { |
2441 | if (rq->rt.overloaded) | |
2442 | rt_clear_overload(rq); | |
6e0534f2 | 2443 | |
7def2be1 PZ |
2444 | __disable_runtime(rq); |
2445 | ||
6e0534f2 | 2446 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 2447 | } |
cb469845 SR |
2448 | |
2449 | /* | |
2450 | * When switch from the rt queue, we bring ourselves to a position | |
2451 | * that we might want to pull RT tasks from other runqueues. | |
2452 | */ | |
da7a735e | 2453 | static void switched_from_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
2454 | { |
2455 | /* | |
2456 | * If there are other RT tasks then we will reschedule | |
2457 | * and the scheduling of the other RT tasks will handle | |
2458 | * the balancing. But if we are the last RT task | |
2459 | * we may need to handle the pulling of RT tasks | |
2460 | * now. | |
2461 | */ | |
da0c1e65 | 2462 | if (!task_on_rq_queued(p) || rq->rt.rt_nr_running) |
1158ddb5 KT |
2463 | return; |
2464 | ||
02d8ec94 | 2465 | rt_queue_pull_task(rq); |
cb469845 | 2466 | } |
3d8cbdf8 | 2467 | |
11c785b7 | 2468 | void __init init_sched_rt_class(void) |
3d8cbdf8 RR |
2469 | { |
2470 | unsigned int i; | |
2471 | ||
029632fb | 2472 | for_each_possible_cpu(i) { |
eaa95840 | 2473 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
6ca09dfc | 2474 | GFP_KERNEL, cpu_to_node(i)); |
029632fb | 2475 | } |
3d8cbdf8 | 2476 | } |
cb469845 SR |
2477 | #endif /* CONFIG_SMP */ |
2478 | ||
2479 | /* | |
2480 | * When switching a task to RT, we may overload the runqueue | |
2481 | * with RT tasks. In this case we try to push them off to | |
2482 | * other runqueues. | |
2483 | */ | |
da7a735e | 2484 | static void switched_to_rt(struct rq *rq, struct task_struct *p) |
cb469845 | 2485 | { |
cb469845 | 2486 | /* |
fecfcbc2 VD |
2487 | * If we are running, update the avg_rt tracking, as the running time |
2488 | * will now on be accounted into the latter. | |
2489 | */ | |
2490 | if (task_current(rq, p)) { | |
2491 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); | |
2492 | return; | |
2493 | } | |
2494 | ||
2495 | /* | |
2496 | * If we are not running we may need to preempt the current | |
2497 | * running task. If that current running task is also an RT task | |
cb469845 SR |
2498 | * then see if we can move to another run queue. |
2499 | */ | |
fecfcbc2 | 2500 | if (task_on_rq_queued(p)) { |
cb469845 | 2501 | #ifdef CONFIG_SMP |
d94a9df4 | 2502 | if (p->nr_cpus_allowed > 1 && rq->rt.overloaded) |
02d8ec94 | 2503 | rt_queue_push_tasks(rq); |
619bd4a7 | 2504 | #endif /* CONFIG_SMP */ |
2fe25826 | 2505 | if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq))) |
8875125e | 2506 | resched_curr(rq); |
cb469845 SR |
2507 | } |
2508 | } | |
2509 | ||
2510 | /* | |
2511 | * Priority of the task has changed. This may cause | |
2512 | * us to initiate a push or pull. | |
2513 | */ | |
da7a735e PZ |
2514 | static void |
2515 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 2516 | { |
da0c1e65 | 2517 | if (!task_on_rq_queued(p)) |
da7a735e PZ |
2518 | return; |
2519 | ||
65bcf072 | 2520 | if (task_current(rq, p)) { |
cb469845 SR |
2521 | #ifdef CONFIG_SMP |
2522 | /* | |
2523 | * If our priority decreases while running, we | |
2524 | * may need to pull tasks to this runqueue. | |
2525 | */ | |
2526 | if (oldprio < p->prio) | |
02d8ec94 | 2527 | rt_queue_pull_task(rq); |
fd7a4bed | 2528 | |
cb469845 SR |
2529 | /* |
2530 | * If there's a higher priority task waiting to run | |
fd7a4bed | 2531 | * then reschedule. |
cb469845 | 2532 | */ |
fd7a4bed | 2533 | if (p->prio > rq->rt.highest_prio.curr) |
8875125e | 2534 | resched_curr(rq); |
cb469845 SR |
2535 | #else |
2536 | /* For UP simply resched on drop of prio */ | |
2537 | if (oldprio < p->prio) | |
8875125e | 2538 | resched_curr(rq); |
e8fa1362 | 2539 | #endif /* CONFIG_SMP */ |
cb469845 SR |
2540 | } else { |
2541 | /* | |
2542 | * This task is not running, but if it is | |
2543 | * greater than the current running task | |
2544 | * then reschedule. | |
2545 | */ | |
2546 | if (p->prio < rq->curr->prio) | |
8875125e | 2547 | resched_curr(rq); |
cb469845 SR |
2548 | } |
2549 | } | |
2550 | ||
b18b6a9c | 2551 | #ifdef CONFIG_POSIX_TIMERS |
78f2c7db PZ |
2552 | static void watchdog(struct rq *rq, struct task_struct *p) |
2553 | { | |
2554 | unsigned long soft, hard; | |
2555 | ||
78d7d407 JS |
2556 | /* max may change after cur was read, this will be fixed next tick */ |
2557 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
2558 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
78f2c7db PZ |
2559 | |
2560 | if (soft != RLIM_INFINITY) { | |
2561 | unsigned long next; | |
2562 | ||
57d2aa00 YX |
2563 | if (p->rt.watchdog_stamp != jiffies) { |
2564 | p->rt.timeout++; | |
2565 | p->rt.watchdog_stamp = jiffies; | |
2566 | } | |
2567 | ||
78f2c7db | 2568 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); |
3a245c0f TG |
2569 | if (p->rt.timeout > next) { |
2570 | posix_cputimers_rt_watchdog(&p->posix_cputimers, | |
2571 | p->se.sum_exec_runtime); | |
2572 | } | |
78f2c7db PZ |
2573 | } |
2574 | } | |
b18b6a9c NP |
2575 | #else |
2576 | static inline void watchdog(struct rq *rq, struct task_struct *p) { } | |
2577 | #endif | |
bb44e5d1 | 2578 | |
d84b3131 FW |
2579 | /* |
2580 | * scheduler tick hitting a task of our scheduling class. | |
2581 | * | |
2582 | * NOTE: This function can be called remotely by the tick offload that | |
2583 | * goes along full dynticks. Therefore no local assumption can be made | |
2584 | * and everything must be accessed through the @rq and @curr passed in | |
2585 | * parameters. | |
2586 | */ | |
8f4d37ec | 2587 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 2588 | { |
454c7999 CC |
2589 | struct sched_rt_entity *rt_se = &p->rt; |
2590 | ||
67e2be02 | 2591 | update_curr_rt(rq); |
23127296 | 2592 | update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); |
67e2be02 | 2593 | |
78f2c7db PZ |
2594 | watchdog(rq, p); |
2595 | ||
bb44e5d1 IM |
2596 | /* |
2597 | * RR tasks need a special form of timeslice management. | |
2598 | * FIFO tasks have no timeslices. | |
2599 | */ | |
2600 | if (p->policy != SCHED_RR) | |
2601 | return; | |
2602 | ||
fa717060 | 2603 | if (--p->rt.time_slice) |
bb44e5d1 IM |
2604 | return; |
2605 | ||
ce0dbbbb | 2606 | p->rt.time_slice = sched_rr_timeslice; |
bb44e5d1 | 2607 | |
98fbc798 | 2608 | /* |
e9aa39bb LB |
2609 | * Requeue to the end of queue if we (and all of our ancestors) are not |
2610 | * the only element on the queue | |
98fbc798 | 2611 | */ |
454c7999 CC |
2612 | for_each_sched_rt_entity(rt_se) { |
2613 | if (rt_se->run_list.prev != rt_se->run_list.next) { | |
2614 | requeue_task_rt(rq, p, 0); | |
8aa6f0eb | 2615 | resched_curr(rq); |
454c7999 CC |
2616 | return; |
2617 | } | |
98fbc798 | 2618 | } |
bb44e5d1 IM |
2619 | } |
2620 | ||
6d686f45 | 2621 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) |
0d721cea PW |
2622 | { |
2623 | /* | |
2624 | * Time slice is 0 for SCHED_FIFO tasks | |
2625 | */ | |
2626 | if (task->policy == SCHED_RR) | |
ce0dbbbb | 2627 | return sched_rr_timeslice; |
0d721cea PW |
2628 | else |
2629 | return 0; | |
2630 | } | |
2631 | ||
530bfad1 HJ |
2632 | #ifdef CONFIG_SCHED_CORE |
2633 | static int task_is_throttled_rt(struct task_struct *p, int cpu) | |
2634 | { | |
2635 | struct rt_rq *rt_rq; | |
2636 | ||
2637 | #ifdef CONFIG_RT_GROUP_SCHED | |
2638 | rt_rq = task_group(p)->rt_rq[cpu]; | |
2639 | #else | |
2640 | rt_rq = &cpu_rq(cpu)->rt; | |
2641 | #endif | |
2642 | ||
2643 | return rt_rq_throttled(rt_rq); | |
2644 | } | |
2645 | #endif | |
2646 | ||
43c31ac0 PZ |
2647 | DEFINE_SCHED_CLASS(rt) = { |
2648 | ||
bb44e5d1 IM |
2649 | .enqueue_task = enqueue_task_rt, |
2650 | .dequeue_task = dequeue_task_rt, | |
2651 | .yield_task = yield_task_rt, | |
2652 | ||
e23edc86 | 2653 | .wakeup_preempt = wakeup_preempt_rt, |
bb44e5d1 IM |
2654 | |
2655 | .pick_next_task = pick_next_task_rt, | |
2656 | .put_prev_task = put_prev_task_rt, | |
03b7fad1 | 2657 | .set_next_task = set_next_task_rt, |
bb44e5d1 | 2658 | |
681f3e68 | 2659 | #ifdef CONFIG_SMP |
6e2df058 | 2660 | .balance = balance_rt, |
21f56ffe | 2661 | .pick_task = pick_task_rt, |
4ce72a2c | 2662 | .select_task_rq = select_task_rq_rt, |
6c37067e | 2663 | .set_cpus_allowed = set_cpus_allowed_common, |
1f11eb6a GH |
2664 | .rq_online = rq_online_rt, |
2665 | .rq_offline = rq_offline_rt, | |
efbbd05a | 2666 | .task_woken = task_woken_rt, |
cb469845 | 2667 | .switched_from = switched_from_rt, |
a7c81556 | 2668 | .find_lock_rq = find_lock_lowest_rq, |
681f3e68 | 2669 | #endif |
bb44e5d1 IM |
2670 | |
2671 | .task_tick = task_tick_rt, | |
cb469845 | 2672 | |
0d721cea PW |
2673 | .get_rr_interval = get_rr_interval_rt, |
2674 | ||
cb469845 SR |
2675 | .prio_changed = prio_changed_rt, |
2676 | .switched_to = switched_to_rt, | |
6e998916 SG |
2677 | |
2678 | .update_curr = update_curr_rt, | |
982d9cdc | 2679 | |
530bfad1 HJ |
2680 | #ifdef CONFIG_SCHED_CORE |
2681 | .task_is_throttled = task_is_throttled_rt, | |
2682 | #endif | |
2683 | ||
982d9cdc PB |
2684 | #ifdef CONFIG_UCLAMP_TASK |
2685 | .uclamp_enabled = 1, | |
2686 | #endif | |
bb44e5d1 | 2687 | }; |
ada18de2 | 2688 | |
8887cd99 NP |
2689 | #ifdef CONFIG_RT_GROUP_SCHED |
2690 | /* | |
2691 | * Ensure that the real time constraints are schedulable. | |
2692 | */ | |
2693 | static DEFINE_MUTEX(rt_constraints_mutex); | |
2694 | ||
8887cd99 NP |
2695 | static inline int tg_has_rt_tasks(struct task_group *tg) |
2696 | { | |
b4fb015e KK |
2697 | struct task_struct *task; |
2698 | struct css_task_iter it; | |
2699 | int ret = 0; | |
8887cd99 NP |
2700 | |
2701 | /* | |
2702 | * Autogroups do not have RT tasks; see autogroup_create(). | |
2703 | */ | |
2704 | if (task_group_is_autogroup(tg)) | |
2705 | return 0; | |
2706 | ||
b4fb015e KK |
2707 | css_task_iter_start(&tg->css, 0, &it); |
2708 | while (!ret && (task = css_task_iter_next(&it))) | |
2709 | ret |= rt_task(task); | |
2710 | css_task_iter_end(&it); | |
8887cd99 | 2711 | |
b4fb015e | 2712 | return ret; |
8887cd99 NP |
2713 | } |
2714 | ||
2715 | struct rt_schedulable_data { | |
2716 | struct task_group *tg; | |
2717 | u64 rt_period; | |
2718 | u64 rt_runtime; | |
2719 | }; | |
2720 | ||
2721 | static int tg_rt_schedulable(struct task_group *tg, void *data) | |
2722 | { | |
2723 | struct rt_schedulable_data *d = data; | |
2724 | struct task_group *child; | |
2725 | unsigned long total, sum = 0; | |
2726 | u64 period, runtime; | |
2727 | ||
2728 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
2729 | runtime = tg->rt_bandwidth.rt_runtime; | |
2730 | ||
2731 | if (tg == d->tg) { | |
2732 | period = d->rt_period; | |
2733 | runtime = d->rt_runtime; | |
2734 | } | |
2735 | ||
2736 | /* | |
2737 | * Cannot have more runtime than the period. | |
2738 | */ | |
2739 | if (runtime > period && runtime != RUNTIME_INF) | |
2740 | return -EINVAL; | |
2741 | ||
2742 | /* | |
b4fb015e | 2743 | * Ensure we don't starve existing RT tasks if runtime turns zero. |
8887cd99 | 2744 | */ |
b4fb015e KK |
2745 | if (rt_bandwidth_enabled() && !runtime && |
2746 | tg->rt_bandwidth.rt_runtime && tg_has_rt_tasks(tg)) | |
8887cd99 NP |
2747 | return -EBUSY; |
2748 | ||
2749 | total = to_ratio(period, runtime); | |
2750 | ||
2751 | /* | |
2752 | * Nobody can have more than the global setting allows. | |
2753 | */ | |
2754 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
2755 | return -EINVAL; | |
2756 | ||
2757 | /* | |
2758 | * The sum of our children's runtime should not exceed our own. | |
2759 | */ | |
2760 | list_for_each_entry_rcu(child, &tg->children, siblings) { | |
2761 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
2762 | runtime = child->rt_bandwidth.rt_runtime; | |
2763 | ||
2764 | if (child == d->tg) { | |
2765 | period = d->rt_period; | |
2766 | runtime = d->rt_runtime; | |
2767 | } | |
2768 | ||
2769 | sum += to_ratio(period, runtime); | |
2770 | } | |
2771 | ||
2772 | if (sum > total) | |
2773 | return -EINVAL; | |
2774 | ||
2775 | return 0; | |
2776 | } | |
2777 | ||
2778 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) | |
2779 | { | |
2780 | int ret; | |
2781 | ||
2782 | struct rt_schedulable_data data = { | |
2783 | .tg = tg, | |
2784 | .rt_period = period, | |
2785 | .rt_runtime = runtime, | |
2786 | }; | |
2787 | ||
2788 | rcu_read_lock(); | |
2789 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
2790 | rcu_read_unlock(); | |
2791 | ||
2792 | return ret; | |
2793 | } | |
2794 | ||
2795 | static int tg_set_rt_bandwidth(struct task_group *tg, | |
2796 | u64 rt_period, u64 rt_runtime) | |
2797 | { | |
2798 | int i, err = 0; | |
2799 | ||
2800 | /* | |
2801 | * Disallowing the root group RT runtime is BAD, it would disallow the | |
2802 | * kernel creating (and or operating) RT threads. | |
2803 | */ | |
2804 | if (tg == &root_task_group && rt_runtime == 0) | |
2805 | return -EINVAL; | |
2806 | ||
2807 | /* No period doesn't make any sense. */ | |
2808 | if (rt_period == 0) | |
2809 | return -EINVAL; | |
2810 | ||
d505b8af HC |
2811 | /* |
2812 | * Bound quota to defend quota against overflow during bandwidth shift. | |
2813 | */ | |
2814 | if (rt_runtime != RUNTIME_INF && rt_runtime > max_rt_runtime) | |
2815 | return -EINVAL; | |
2816 | ||
8887cd99 | 2817 | mutex_lock(&rt_constraints_mutex); |
8887cd99 NP |
2818 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
2819 | if (err) | |
2820 | goto unlock; | |
2821 | ||
2822 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
2823 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); | |
2824 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
2825 | ||
2826 | for_each_possible_cpu(i) { | |
2827 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
2828 | ||
2829 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
2830 | rt_rq->rt_runtime = rt_runtime; | |
2831 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
2832 | } | |
2833 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
2834 | unlock: | |
8887cd99 NP |
2835 | mutex_unlock(&rt_constraints_mutex); |
2836 | ||
2837 | return err; | |
2838 | } | |
2839 | ||
2840 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) | |
2841 | { | |
2842 | u64 rt_runtime, rt_period; | |
2843 | ||
2844 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
2845 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
2846 | if (rt_runtime_us < 0) | |
2847 | rt_runtime = RUNTIME_INF; | |
1a010e29 KK |
2848 | else if ((u64)rt_runtime_us > U64_MAX / NSEC_PER_USEC) |
2849 | return -EINVAL; | |
8887cd99 NP |
2850 | |
2851 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); | |
2852 | } | |
2853 | ||
2854 | long sched_group_rt_runtime(struct task_group *tg) | |
2855 | { | |
2856 | u64 rt_runtime_us; | |
2857 | ||
2858 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) | |
2859 | return -1; | |
2860 | ||
2861 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; | |
2862 | do_div(rt_runtime_us, NSEC_PER_USEC); | |
2863 | return rt_runtime_us; | |
2864 | } | |
2865 | ||
2866 | int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us) | |
2867 | { | |
2868 | u64 rt_runtime, rt_period; | |
2869 | ||
1a010e29 KK |
2870 | if (rt_period_us > U64_MAX / NSEC_PER_USEC) |
2871 | return -EINVAL; | |
2872 | ||
8887cd99 NP |
2873 | rt_period = rt_period_us * NSEC_PER_USEC; |
2874 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
2875 | ||
2876 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); | |
2877 | } | |
2878 | ||
2879 | long sched_group_rt_period(struct task_group *tg) | |
2880 | { | |
2881 | u64 rt_period_us; | |
2882 | ||
2883 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
2884 | do_div(rt_period_us, NSEC_PER_USEC); | |
2885 | return rt_period_us; | |
2886 | } | |
2887 | ||
28f152cd | 2888 | #ifdef CONFIG_SYSCTL |
8887cd99 NP |
2889 | static int sched_rt_global_constraints(void) |
2890 | { | |
2891 | int ret = 0; | |
2892 | ||
2893 | mutex_lock(&rt_constraints_mutex); | |
8887cd99 | 2894 | ret = __rt_schedulable(NULL, 0, 0); |
8887cd99 NP |
2895 | mutex_unlock(&rt_constraints_mutex); |
2896 | ||
2897 | return ret; | |
2898 | } | |
28f152cd | 2899 | #endif /* CONFIG_SYSCTL */ |
8887cd99 NP |
2900 | |
2901 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
2902 | { | |
2903 | /* Don't accept realtime tasks when there is no way for them to run */ | |
2904 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
2905 | return 0; | |
2906 | ||
2907 | return 1; | |
2908 | } | |
2909 | ||
2910 | #else /* !CONFIG_RT_GROUP_SCHED */ | |
28f152cd BZ |
2911 | |
2912 | #ifdef CONFIG_SYSCTL | |
8887cd99 NP |
2913 | static int sched_rt_global_constraints(void) |
2914 | { | |
2915 | unsigned long flags; | |
2916 | int i; | |
2917 | ||
2918 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); | |
2919 | for_each_possible_cpu(i) { | |
2920 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
2921 | ||
2922 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
2923 | rt_rq->rt_runtime = global_rt_runtime(); | |
2924 | raw_spin_unlock(&rt_rq->rt_runtime_lock); | |
2925 | } | |
2926 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); | |
2927 | ||
2928 | return 0; | |
2929 | } | |
28f152cd | 2930 | #endif /* CONFIG_SYSCTL */ |
8887cd99 NP |
2931 | #endif /* CONFIG_RT_GROUP_SCHED */ |
2932 | ||
28f152cd | 2933 | #ifdef CONFIG_SYSCTL |
8887cd99 NP |
2934 | static int sched_rt_global_validate(void) |
2935 | { | |
8887cd99 | 2936 | if ((sysctl_sched_rt_runtime != RUNTIME_INF) && |
d505b8af HC |
2937 | ((sysctl_sched_rt_runtime > sysctl_sched_rt_period) || |
2938 | ((u64)sysctl_sched_rt_runtime * | |
2939 | NSEC_PER_USEC > max_rt_runtime))) | |
8887cd99 NP |
2940 | return -EINVAL; |
2941 | ||
2942 | return 0; | |
2943 | } | |
2944 | ||
2945 | static void sched_rt_do_global(void) | |
2946 | { | |
9b58e976 LH |
2947 | unsigned long flags; |
2948 | ||
2949 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); | |
8887cd99 NP |
2950 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); |
2951 | def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); | |
9b58e976 | 2952 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
8887cd99 NP |
2953 | } |
2954 | ||
d9ab0e63 | 2955 | static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, |
32927393 | 2956 | size_t *lenp, loff_t *ppos) |
8887cd99 NP |
2957 | { |
2958 | int old_period, old_runtime; | |
2959 | static DEFINE_MUTEX(mutex); | |
2960 | int ret; | |
2961 | ||
2962 | mutex_lock(&mutex); | |
2963 | old_period = sysctl_sched_rt_period; | |
2964 | old_runtime = sysctl_sched_rt_runtime; | |
2965 | ||
079be8fc | 2966 | ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
8887cd99 NP |
2967 | |
2968 | if (!ret && write) { | |
2969 | ret = sched_rt_global_validate(); | |
2970 | if (ret) | |
2971 | goto undo; | |
2972 | ||
2973 | ret = sched_dl_global_validate(); | |
2974 | if (ret) | |
2975 | goto undo; | |
2976 | ||
2977 | ret = sched_rt_global_constraints(); | |
2978 | if (ret) | |
2979 | goto undo; | |
2980 | ||
2981 | sched_rt_do_global(); | |
2982 | sched_dl_do_global(); | |
2983 | } | |
2984 | if (0) { | |
2985 | undo: | |
2986 | sysctl_sched_rt_period = old_period; | |
2987 | sysctl_sched_rt_runtime = old_runtime; | |
2988 | } | |
2989 | mutex_unlock(&mutex); | |
2990 | ||
2991 | return ret; | |
2992 | } | |
2993 | ||
dafd7a9d | 2994 | static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, |
32927393 | 2995 | size_t *lenp, loff_t *ppos) |
8887cd99 NP |
2996 | { |
2997 | int ret; | |
2998 | static DEFINE_MUTEX(mutex); | |
2999 | ||
3000 | mutex_lock(&mutex); | |
3001 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
3002 | /* | |
3003 | * Make sure that internally we keep jiffies. | |
3004 | * Also, writing zero resets the timeslice to default: | |
3005 | */ | |
3006 | if (!ret && write) { | |
3007 | sched_rr_timeslice = | |
3008 | sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE : | |
3009 | msecs_to_jiffies(sysctl_sched_rr_timeslice); | |
c1fc6484 CH |
3010 | |
3011 | if (sysctl_sched_rr_timeslice <= 0) | |
3012 | sysctl_sched_rr_timeslice = jiffies_to_msecs(RR_TIMESLICE); | |
8887cd99 NP |
3013 | } |
3014 | mutex_unlock(&mutex); | |
97fb7a0a | 3015 | |
8887cd99 NP |
3016 | return ret; |
3017 | } | |
28f152cd | 3018 | #endif /* CONFIG_SYSCTL */ |
8887cd99 | 3019 | |
ada18de2 | 3020 | #ifdef CONFIG_SCHED_DEBUG |
029632fb | 3021 | void print_rt_stats(struct seq_file *m, int cpu) |
ada18de2 | 3022 | { |
ec514c48 | 3023 | rt_rq_iter_t iter; |
ada18de2 PZ |
3024 | struct rt_rq *rt_rq; |
3025 | ||
3026 | rcu_read_lock(); | |
ec514c48 | 3027 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) |
ada18de2 PZ |
3028 | print_rt_rq(m, cpu, rt_rq); |
3029 | rcu_read_unlock(); | |
3030 | } | |
55e12e5e | 3031 | #endif /* CONFIG_SCHED_DEBUG */ |