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Commit | Line | Data |
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bb44e5d1 IM |
1 | /* |
2 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR | |
3 | * policies) | |
4 | */ | |
5 | ||
8f48894f PZ |
6 | #ifdef CONFIG_RT_GROUP_SCHED |
7 | ||
8 | #define rt_entity_is_task(rt_se) (!(rt_se)->my_q) | |
9 | ||
398a153b GH |
10 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
11 | { | |
8f48894f PZ |
12 | #ifdef CONFIG_SCHED_DEBUG |
13 | WARN_ON_ONCE(!rt_entity_is_task(rt_se)); | |
14 | #endif | |
398a153b GH |
15 | return container_of(rt_se, struct task_struct, rt); |
16 | } | |
17 | ||
398a153b GH |
18 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
19 | { | |
20 | return rt_rq->rq; | |
21 | } | |
22 | ||
23 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
24 | { | |
25 | return rt_se->rt_rq; | |
26 | } | |
27 | ||
28 | #else /* CONFIG_RT_GROUP_SCHED */ | |
29 | ||
a1ba4d8b PZ |
30 | #define rt_entity_is_task(rt_se) (1) |
31 | ||
8f48894f PZ |
32 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
33 | { | |
34 | return container_of(rt_se, struct task_struct, rt); | |
35 | } | |
36 | ||
398a153b GH |
37 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
38 | { | |
39 | return container_of(rt_rq, struct rq, rt); | |
40 | } | |
41 | ||
42 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
43 | { | |
44 | struct task_struct *p = rt_task_of(rt_se); | |
45 | struct rq *rq = task_rq(p); | |
46 | ||
47 | return &rq->rt; | |
48 | } | |
49 | ||
50 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
51 | ||
4fd29176 | 52 | #ifdef CONFIG_SMP |
84de4274 | 53 | |
637f5085 | 54 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 55 | { |
637f5085 | 56 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 57 | } |
84de4274 | 58 | |
4fd29176 SR |
59 | static inline void rt_set_overload(struct rq *rq) |
60 | { | |
1f11eb6a GH |
61 | if (!rq->online) |
62 | return; | |
63 | ||
c6c4927b | 64 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
65 | /* |
66 | * Make sure the mask is visible before we set | |
67 | * the overload count. That is checked to determine | |
68 | * if we should look at the mask. It would be a shame | |
69 | * if we looked at the mask, but the mask was not | |
70 | * updated yet. | |
71 | */ | |
72 | wmb(); | |
637f5085 | 73 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 74 | } |
84de4274 | 75 | |
4fd29176 SR |
76 | static inline void rt_clear_overload(struct rq *rq) |
77 | { | |
1f11eb6a GH |
78 | if (!rq->online) |
79 | return; | |
80 | ||
4fd29176 | 81 | /* the order here really doesn't matter */ |
637f5085 | 82 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 83 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 84 | } |
73fe6aae | 85 | |
398a153b | 86 | static void update_rt_migration(struct rt_rq *rt_rq) |
73fe6aae | 87 | { |
a1ba4d8b | 88 | if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) { |
398a153b GH |
89 | if (!rt_rq->overloaded) { |
90 | rt_set_overload(rq_of_rt_rq(rt_rq)); | |
91 | rt_rq->overloaded = 1; | |
cdc8eb98 | 92 | } |
398a153b GH |
93 | } else if (rt_rq->overloaded) { |
94 | rt_clear_overload(rq_of_rt_rq(rt_rq)); | |
95 | rt_rq->overloaded = 0; | |
637f5085 | 96 | } |
73fe6aae | 97 | } |
4fd29176 | 98 | |
398a153b GH |
99 | static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
100 | { | |
a1ba4d8b PZ |
101 | if (!rt_entity_is_task(rt_se)) |
102 | return; | |
103 | ||
104 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; | |
105 | ||
106 | rt_rq->rt_nr_total++; | |
398a153b GH |
107 | if (rt_se->nr_cpus_allowed > 1) |
108 | rt_rq->rt_nr_migratory++; | |
109 | ||
110 | update_rt_migration(rt_rq); | |
111 | } | |
112 | ||
113 | static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
114 | { | |
a1ba4d8b PZ |
115 | if (!rt_entity_is_task(rt_se)) |
116 | return; | |
117 | ||
118 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; | |
119 | ||
120 | rt_rq->rt_nr_total--; | |
398a153b GH |
121 | if (rt_se->nr_cpus_allowed > 1) |
122 | rt_rq->rt_nr_migratory--; | |
123 | ||
124 | update_rt_migration(rt_rq); | |
125 | } | |
126 | ||
917b627d GH |
127 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
128 | { | |
129 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
130 | plist_node_init(&p->pushable_tasks, p->prio); | |
131 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
132 | } | |
133 | ||
134 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
135 | { | |
136 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
137 | } | |
138 | ||
bcf08df3 IM |
139 | static inline int has_pushable_tasks(struct rq *rq) |
140 | { | |
141 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
142 | } | |
143 | ||
917b627d GH |
144 | #else |
145 | ||
ceacc2c1 | 146 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
fa85ae24 | 147 | { |
6f505b16 PZ |
148 | } |
149 | ||
ceacc2c1 PZ |
150 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
151 | { | |
152 | } | |
153 | ||
b07430ac | 154 | static inline |
ceacc2c1 PZ |
155 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
156 | { | |
157 | } | |
158 | ||
398a153b | 159 | static inline |
ceacc2c1 PZ |
160 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
161 | { | |
162 | } | |
917b627d | 163 | |
4fd29176 SR |
164 | #endif /* CONFIG_SMP */ |
165 | ||
6f505b16 PZ |
166 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
167 | { | |
168 | return !list_empty(&rt_se->run_list); | |
169 | } | |
170 | ||
052f1dc7 | 171 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 172 | |
9f0c1e56 | 173 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
174 | { |
175 | if (!rt_rq->tg) | |
9f0c1e56 | 176 | return RUNTIME_INF; |
6f505b16 | 177 | |
ac086bc2 PZ |
178 | return rt_rq->rt_runtime; |
179 | } | |
180 | ||
181 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
182 | { | |
183 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
184 | } |
185 | ||
ec514c48 CX |
186 | typedef struct task_group *rt_rq_iter_t; |
187 | ||
188 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
189 | for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \ | |
190 | (&iter->list != &task_groups) && \ | |
191 | (rt_rq = iter->rt_rq[cpu_of(rq)]); \ | |
192 | iter = list_entry_rcu(iter->list.next, typeof(*iter), list)) | |
193 | ||
3d4b47b4 PZ |
194 | static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) |
195 | { | |
196 | list_add_rcu(&rt_rq->leaf_rt_rq_list, | |
197 | &rq_of_rt_rq(rt_rq)->leaf_rt_rq_list); | |
198 | } | |
199 | ||
200 | static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq) | |
201 | { | |
202 | list_del_rcu(&rt_rq->leaf_rt_rq_list); | |
203 | } | |
204 | ||
6f505b16 | 205 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
80f40ee4 | 206 | list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) |
6f505b16 | 207 | |
6f505b16 PZ |
208 | #define for_each_sched_rt_entity(rt_se) \ |
209 | for (; rt_se; rt_se = rt_se->parent) | |
210 | ||
211 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
212 | { | |
213 | return rt_se->my_q; | |
214 | } | |
215 | ||
37dad3fc | 216 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head); |
6f505b16 PZ |
217 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se); |
218 | ||
9f0c1e56 | 219 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 220 | { |
f6121f4f | 221 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
74b7eb58 YZ |
222 | struct sched_rt_entity *rt_se; |
223 | ||
0c3b9168 BS |
224 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
225 | ||
226 | rt_se = rt_rq->tg->rt_se[cpu]; | |
6f505b16 | 227 | |
f6121f4f DF |
228 | if (rt_rq->rt_nr_running) { |
229 | if (rt_se && !on_rt_rq(rt_se)) | |
37dad3fc | 230 | enqueue_rt_entity(rt_se, false); |
e864c499 | 231 | if (rt_rq->highest_prio.curr < curr->prio) |
1020387f | 232 | resched_task(curr); |
6f505b16 PZ |
233 | } |
234 | } | |
235 | ||
9f0c1e56 | 236 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 237 | { |
74b7eb58 | 238 | struct sched_rt_entity *rt_se; |
0c3b9168 | 239 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
74b7eb58 | 240 | |
0c3b9168 | 241 | rt_se = rt_rq->tg->rt_se[cpu]; |
6f505b16 PZ |
242 | |
243 | if (rt_se && on_rt_rq(rt_se)) | |
244 | dequeue_rt_entity(rt_se); | |
245 | } | |
246 | ||
23b0fdfc PZ |
247 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
248 | { | |
249 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
250 | } | |
251 | ||
252 | static int rt_se_boosted(struct sched_rt_entity *rt_se) | |
253 | { | |
254 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
255 | struct task_struct *p; | |
256 | ||
257 | if (rt_rq) | |
258 | return !!rt_rq->rt_nr_boosted; | |
259 | ||
260 | p = rt_task_of(rt_se); | |
261 | return p->prio != p->normal_prio; | |
262 | } | |
263 | ||
d0b27fa7 | 264 | #ifdef CONFIG_SMP |
c6c4927b | 265 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 PZ |
266 | { |
267 | return cpu_rq(smp_processor_id())->rd->span; | |
268 | } | |
6f505b16 | 269 | #else |
c6c4927b | 270 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 271 | { |
c6c4927b | 272 | return cpu_online_mask; |
d0b27fa7 PZ |
273 | } |
274 | #endif | |
6f505b16 | 275 | |
d0b27fa7 PZ |
276 | static inline |
277 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 278 | { |
d0b27fa7 PZ |
279 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
280 | } | |
9f0c1e56 | 281 | |
ac086bc2 PZ |
282 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
283 | { | |
284 | return &rt_rq->tg->rt_bandwidth; | |
285 | } | |
286 | ||
55e12e5e | 287 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
288 | |
289 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
290 | { | |
ac086bc2 PZ |
291 | return rt_rq->rt_runtime; |
292 | } | |
293 | ||
294 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
295 | { | |
296 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
297 | } |
298 | ||
ec514c48 CX |
299 | typedef struct rt_rq *rt_rq_iter_t; |
300 | ||
301 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
302 | for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
303 | ||
3d4b47b4 PZ |
304 | static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) |
305 | { | |
306 | } | |
307 | ||
308 | static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq) | |
309 | { | |
310 | } | |
311 | ||
6f505b16 PZ |
312 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
313 | for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
314 | ||
6f505b16 PZ |
315 | #define for_each_sched_rt_entity(rt_se) \ |
316 | for (; rt_se; rt_se = NULL) | |
317 | ||
318 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
319 | { | |
320 | return NULL; | |
321 | } | |
322 | ||
9f0c1e56 | 323 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 324 | { |
f3ade837 JB |
325 | if (rt_rq->rt_nr_running) |
326 | resched_task(rq_of_rt_rq(rt_rq)->curr); | |
6f505b16 PZ |
327 | } |
328 | ||
9f0c1e56 | 329 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
330 | { |
331 | } | |
332 | ||
23b0fdfc PZ |
333 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
334 | { | |
335 | return rt_rq->rt_throttled; | |
336 | } | |
d0b27fa7 | 337 | |
c6c4927b | 338 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 339 | { |
c6c4927b | 340 | return cpu_online_mask; |
d0b27fa7 PZ |
341 | } |
342 | ||
343 | static inline | |
344 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
345 | { | |
346 | return &cpu_rq(cpu)->rt; | |
347 | } | |
348 | ||
ac086bc2 PZ |
349 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
350 | { | |
351 | return &def_rt_bandwidth; | |
352 | } | |
353 | ||
55e12e5e | 354 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 355 | |
ac086bc2 | 356 | #ifdef CONFIG_SMP |
78333cdd PZ |
357 | /* |
358 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
359 | */ | |
b79f3833 | 360 | static int do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
361 | { |
362 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
363 | struct root_domain *rd = cpu_rq(smp_processor_id())->rd; | |
364 | int i, weight, more = 0; | |
365 | u64 rt_period; | |
366 | ||
c6c4927b | 367 | weight = cpumask_weight(rd->span); |
ac086bc2 | 368 | |
0986b11b | 369 | raw_spin_lock(&rt_b->rt_runtime_lock); |
ac086bc2 | 370 | rt_period = ktime_to_ns(rt_b->rt_period); |
c6c4927b | 371 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
372 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
373 | s64 diff; | |
374 | ||
375 | if (iter == rt_rq) | |
376 | continue; | |
377 | ||
0986b11b | 378 | raw_spin_lock(&iter->rt_runtime_lock); |
78333cdd PZ |
379 | /* |
380 | * Either all rqs have inf runtime and there's nothing to steal | |
381 | * or __disable_runtime() below sets a specific rq to inf to | |
382 | * indicate its been disabled and disalow stealing. | |
383 | */ | |
7def2be1 PZ |
384 | if (iter->rt_runtime == RUNTIME_INF) |
385 | goto next; | |
386 | ||
78333cdd PZ |
387 | /* |
388 | * From runqueues with spare time, take 1/n part of their | |
389 | * spare time, but no more than our period. | |
390 | */ | |
ac086bc2 PZ |
391 | diff = iter->rt_runtime - iter->rt_time; |
392 | if (diff > 0) { | |
58838cf3 | 393 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
394 | if (rt_rq->rt_runtime + diff > rt_period) |
395 | diff = rt_period - rt_rq->rt_runtime; | |
396 | iter->rt_runtime -= diff; | |
397 | rt_rq->rt_runtime += diff; | |
398 | more = 1; | |
399 | if (rt_rq->rt_runtime == rt_period) { | |
0986b11b | 400 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 PZ |
401 | break; |
402 | } | |
403 | } | |
7def2be1 | 404 | next: |
0986b11b | 405 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 | 406 | } |
0986b11b | 407 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
ac086bc2 PZ |
408 | |
409 | return more; | |
410 | } | |
7def2be1 | 411 | |
78333cdd PZ |
412 | /* |
413 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
414 | */ | |
7def2be1 PZ |
415 | static void __disable_runtime(struct rq *rq) |
416 | { | |
417 | struct root_domain *rd = rq->rd; | |
ec514c48 | 418 | rt_rq_iter_t iter; |
7def2be1 PZ |
419 | struct rt_rq *rt_rq; |
420 | ||
421 | if (unlikely(!scheduler_running)) | |
422 | return; | |
423 | ||
ec514c48 | 424 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
425 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
426 | s64 want; | |
427 | int i; | |
428 | ||
0986b11b TG |
429 | raw_spin_lock(&rt_b->rt_runtime_lock); |
430 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
431 | /* |
432 | * Either we're all inf and nobody needs to borrow, or we're | |
433 | * already disabled and thus have nothing to do, or we have | |
434 | * exactly the right amount of runtime to take out. | |
435 | */ | |
7def2be1 PZ |
436 | if (rt_rq->rt_runtime == RUNTIME_INF || |
437 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
438 | goto balanced; | |
0986b11b | 439 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
7def2be1 | 440 | |
78333cdd PZ |
441 | /* |
442 | * Calculate the difference between what we started out with | |
443 | * and what we current have, that's the amount of runtime | |
444 | * we lend and now have to reclaim. | |
445 | */ | |
7def2be1 PZ |
446 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
447 | ||
78333cdd PZ |
448 | /* |
449 | * Greedy reclaim, take back as much as we can. | |
450 | */ | |
c6c4927b | 451 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
452 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
453 | s64 diff; | |
454 | ||
78333cdd PZ |
455 | /* |
456 | * Can't reclaim from ourselves or disabled runqueues. | |
457 | */ | |
f1679d08 | 458 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
459 | continue; |
460 | ||
0986b11b | 461 | raw_spin_lock(&iter->rt_runtime_lock); |
7def2be1 PZ |
462 | if (want > 0) { |
463 | diff = min_t(s64, iter->rt_runtime, want); | |
464 | iter->rt_runtime -= diff; | |
465 | want -= diff; | |
466 | } else { | |
467 | iter->rt_runtime -= want; | |
468 | want -= want; | |
469 | } | |
0986b11b | 470 | raw_spin_unlock(&iter->rt_runtime_lock); |
7def2be1 PZ |
471 | |
472 | if (!want) | |
473 | break; | |
474 | } | |
475 | ||
0986b11b | 476 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
78333cdd PZ |
477 | /* |
478 | * We cannot be left wanting - that would mean some runtime | |
479 | * leaked out of the system. | |
480 | */ | |
7def2be1 PZ |
481 | BUG_ON(want); |
482 | balanced: | |
78333cdd PZ |
483 | /* |
484 | * Disable all the borrow logic by pretending we have inf | |
485 | * runtime - in which case borrowing doesn't make sense. | |
486 | */ | |
7def2be1 | 487 | rt_rq->rt_runtime = RUNTIME_INF; |
0986b11b TG |
488 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
489 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
490 | } |
491 | } | |
492 | ||
493 | static void disable_runtime(struct rq *rq) | |
494 | { | |
495 | unsigned long flags; | |
496 | ||
05fa785c | 497 | raw_spin_lock_irqsave(&rq->lock, flags); |
7def2be1 | 498 | __disable_runtime(rq); |
05fa785c | 499 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
7def2be1 PZ |
500 | } |
501 | ||
502 | static void __enable_runtime(struct rq *rq) | |
503 | { | |
ec514c48 | 504 | rt_rq_iter_t iter; |
7def2be1 PZ |
505 | struct rt_rq *rt_rq; |
506 | ||
507 | if (unlikely(!scheduler_running)) | |
508 | return; | |
509 | ||
78333cdd PZ |
510 | /* |
511 | * Reset each runqueue's bandwidth settings | |
512 | */ | |
ec514c48 | 513 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
514 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
515 | ||
0986b11b TG |
516 | raw_spin_lock(&rt_b->rt_runtime_lock); |
517 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
7def2be1 PZ |
518 | rt_rq->rt_runtime = rt_b->rt_runtime; |
519 | rt_rq->rt_time = 0; | |
baf25731 | 520 | rt_rq->rt_throttled = 0; |
0986b11b TG |
521 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
522 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
523 | } |
524 | } | |
525 | ||
526 | static void enable_runtime(struct rq *rq) | |
527 | { | |
528 | unsigned long flags; | |
529 | ||
05fa785c | 530 | raw_spin_lock_irqsave(&rq->lock, flags); |
7def2be1 | 531 | __enable_runtime(rq); |
05fa785c | 532 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
7def2be1 PZ |
533 | } |
534 | ||
eff6549b PZ |
535 | static int balance_runtime(struct rt_rq *rt_rq) |
536 | { | |
537 | int more = 0; | |
538 | ||
539 | if (rt_rq->rt_time > rt_rq->rt_runtime) { | |
0986b11b | 540 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
eff6549b | 541 | more = do_balance_runtime(rt_rq); |
0986b11b | 542 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
543 | } |
544 | ||
545 | return more; | |
546 | } | |
55e12e5e | 547 | #else /* !CONFIG_SMP */ |
eff6549b PZ |
548 | static inline int balance_runtime(struct rt_rq *rt_rq) |
549 | { | |
550 | return 0; | |
551 | } | |
55e12e5e | 552 | #endif /* CONFIG_SMP */ |
ac086bc2 | 553 | |
eff6549b PZ |
554 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
555 | { | |
556 | int i, idle = 1; | |
c6c4927b | 557 | const struct cpumask *span; |
eff6549b | 558 | |
0b148fa0 | 559 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
eff6549b PZ |
560 | return 1; |
561 | ||
562 | span = sched_rt_period_mask(); | |
c6c4927b | 563 | for_each_cpu(i, span) { |
eff6549b PZ |
564 | int enqueue = 0; |
565 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
566 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
567 | ||
05fa785c | 568 | raw_spin_lock(&rq->lock); |
eff6549b PZ |
569 | if (rt_rq->rt_time) { |
570 | u64 runtime; | |
571 | ||
0986b11b | 572 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
573 | if (rt_rq->rt_throttled) |
574 | balance_runtime(rt_rq); | |
575 | runtime = rt_rq->rt_runtime; | |
576 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
577 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
578 | rt_rq->rt_throttled = 0; | |
579 | enqueue = 1; | |
61eadef6 MG |
580 | |
581 | /* | |
582 | * Force a clock update if the CPU was idle, | |
583 | * lest wakeup -> unthrottle time accumulate. | |
584 | */ | |
585 | if (rt_rq->rt_nr_running && rq->curr == rq->idle) | |
586 | rq->skip_clock_update = -1; | |
eff6549b PZ |
587 | } |
588 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
589 | idle = 0; | |
0986b11b | 590 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
0c3b9168 | 591 | } else if (rt_rq->rt_nr_running) { |
6c3df255 | 592 | idle = 0; |
0c3b9168 BS |
593 | if (!rt_rq_throttled(rt_rq)) |
594 | enqueue = 1; | |
595 | } | |
eff6549b PZ |
596 | |
597 | if (enqueue) | |
598 | sched_rt_rq_enqueue(rt_rq); | |
05fa785c | 599 | raw_spin_unlock(&rq->lock); |
eff6549b PZ |
600 | } |
601 | ||
602 | return idle; | |
603 | } | |
ac086bc2 | 604 | |
6f505b16 PZ |
605 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
606 | { | |
052f1dc7 | 607 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
608 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
609 | ||
610 | if (rt_rq) | |
e864c499 | 611 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
612 | #endif |
613 | ||
614 | return rt_task_of(rt_se)->prio; | |
615 | } | |
616 | ||
9f0c1e56 | 617 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 618 | { |
9f0c1e56 | 619 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 620 | |
fa85ae24 | 621 | if (rt_rq->rt_throttled) |
23b0fdfc | 622 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 623 | |
ac086bc2 PZ |
624 | if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) |
625 | return 0; | |
626 | ||
b79f3833 PZ |
627 | balance_runtime(rt_rq); |
628 | runtime = sched_rt_runtime(rt_rq); | |
629 | if (runtime == RUNTIME_INF) | |
630 | return 0; | |
ac086bc2 | 631 | |
9f0c1e56 | 632 | if (rt_rq->rt_time > runtime) { |
6f505b16 | 633 | rt_rq->rt_throttled = 1; |
23b0fdfc | 634 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 635 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
636 | return 1; |
637 | } | |
fa85ae24 PZ |
638 | } |
639 | ||
640 | return 0; | |
641 | } | |
642 | ||
bb44e5d1 IM |
643 | /* |
644 | * Update the current task's runtime statistics. Skip current tasks that | |
645 | * are not in our scheduling class. | |
646 | */ | |
a9957449 | 647 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
648 | { |
649 | struct task_struct *curr = rq->curr; | |
6f505b16 PZ |
650 | struct sched_rt_entity *rt_se = &curr->rt; |
651 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
bb44e5d1 IM |
652 | u64 delta_exec; |
653 | ||
06c3bc65 | 654 | if (curr->sched_class != &rt_sched_class) |
bb44e5d1 IM |
655 | return; |
656 | ||
305e6835 | 657 | delta_exec = rq->clock_task - curr->se.exec_start; |
bb44e5d1 IM |
658 | if (unlikely((s64)delta_exec < 0)) |
659 | delta_exec = 0; | |
6cfb0d5d | 660 | |
41acab88 | 661 | schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec)); |
bb44e5d1 IM |
662 | |
663 | curr->se.sum_exec_runtime += delta_exec; | |
f06febc9 FM |
664 | account_group_exec_runtime(curr, delta_exec); |
665 | ||
305e6835 | 666 | curr->se.exec_start = rq->clock_task; |
d842de87 | 667 | cpuacct_charge(curr, delta_exec); |
fa85ae24 | 668 | |
e9e9250b PZ |
669 | sched_rt_avg_update(rq, delta_exec); |
670 | ||
0b148fa0 PZ |
671 | if (!rt_bandwidth_enabled()) |
672 | return; | |
673 | ||
354d60c2 DG |
674 | for_each_sched_rt_entity(rt_se) { |
675 | rt_rq = rt_rq_of_se(rt_se); | |
676 | ||
cc2991cf | 677 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
0986b11b | 678 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf PZ |
679 | rt_rq->rt_time += delta_exec; |
680 | if (sched_rt_runtime_exceeded(rt_rq)) | |
681 | resched_task(curr); | |
0986b11b | 682 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
cc2991cf | 683 | } |
354d60c2 | 684 | } |
bb44e5d1 IM |
685 | } |
686 | ||
398a153b | 687 | #if defined CONFIG_SMP |
e864c499 GH |
688 | |
689 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu); | |
690 | ||
691 | static inline int next_prio(struct rq *rq) | |
63489e45 | 692 | { |
e864c499 GH |
693 | struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu); |
694 | ||
695 | if (next && rt_prio(next->prio)) | |
696 | return next->prio; | |
697 | else | |
698 | return MAX_RT_PRIO; | |
699 | } | |
e864c499 | 700 | |
398a153b GH |
701 | static void |
702 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 703 | { |
4d984277 | 704 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 705 | |
398a153b | 706 | if (prio < prev_prio) { |
4d984277 | 707 | |
e864c499 GH |
708 | /* |
709 | * If the new task is higher in priority than anything on the | |
398a153b GH |
710 | * run-queue, we know that the previous high becomes our |
711 | * next-highest. | |
e864c499 | 712 | */ |
398a153b | 713 | rt_rq->highest_prio.next = prev_prio; |
1f11eb6a GH |
714 | |
715 | if (rq->online) | |
4d984277 | 716 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); |
1100ac91 | 717 | |
e864c499 GH |
718 | } else if (prio == rt_rq->highest_prio.curr) |
719 | /* | |
720 | * If the next task is equal in priority to the highest on | |
721 | * the run-queue, then we implicitly know that the next highest | |
722 | * task cannot be any lower than current | |
723 | */ | |
724 | rt_rq->highest_prio.next = prio; | |
725 | else if (prio < rt_rq->highest_prio.next) | |
726 | /* | |
727 | * Otherwise, we need to recompute next-highest | |
728 | */ | |
729 | rt_rq->highest_prio.next = next_prio(rq); | |
398a153b | 730 | } |
73fe6aae | 731 | |
398a153b GH |
732 | static void |
733 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
734 | { | |
735 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 736 | |
398a153b GH |
737 | if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next)) |
738 | rt_rq->highest_prio.next = next_prio(rq); | |
739 | ||
740 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) | |
741 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
742 | } |
743 | ||
398a153b GH |
744 | #else /* CONFIG_SMP */ |
745 | ||
6f505b16 | 746 | static inline |
398a153b GH |
747 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
748 | static inline | |
749 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
750 | ||
751 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 752 | |
052f1dc7 | 753 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
754 | static void |
755 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
756 | { | |
757 | int prev_prio = rt_rq->highest_prio.curr; | |
758 | ||
759 | if (prio < prev_prio) | |
760 | rt_rq->highest_prio.curr = prio; | |
761 | ||
762 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
763 | } | |
764 | ||
765 | static void | |
766 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
767 | { | |
768 | int prev_prio = rt_rq->highest_prio.curr; | |
769 | ||
6f505b16 | 770 | if (rt_rq->rt_nr_running) { |
764a9d6f | 771 | |
398a153b | 772 | WARN_ON(prio < prev_prio); |
764a9d6f | 773 | |
e864c499 | 774 | /* |
398a153b GH |
775 | * This may have been our highest task, and therefore |
776 | * we may have some recomputation to do | |
e864c499 | 777 | */ |
398a153b | 778 | if (prio == prev_prio) { |
e864c499 GH |
779 | struct rt_prio_array *array = &rt_rq->active; |
780 | ||
781 | rt_rq->highest_prio.curr = | |
764a9d6f | 782 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
783 | } |
784 | ||
764a9d6f | 785 | } else |
e864c499 | 786 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
73fe6aae | 787 | |
398a153b GH |
788 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
789 | } | |
1f11eb6a | 790 | |
398a153b GH |
791 | #else |
792 | ||
793 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
794 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
795 | ||
796 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 797 | |
052f1dc7 | 798 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
799 | |
800 | static void | |
801 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
802 | { | |
803 | if (rt_se_boosted(rt_se)) | |
804 | rt_rq->rt_nr_boosted++; | |
805 | ||
806 | if (rt_rq->tg) | |
807 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
808 | } | |
809 | ||
810 | static void | |
811 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
812 | { | |
23b0fdfc PZ |
813 | if (rt_se_boosted(rt_se)) |
814 | rt_rq->rt_nr_boosted--; | |
815 | ||
816 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
398a153b GH |
817 | } |
818 | ||
819 | #else /* CONFIG_RT_GROUP_SCHED */ | |
820 | ||
821 | static void | |
822 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
823 | { | |
824 | start_rt_bandwidth(&def_rt_bandwidth); | |
825 | } | |
826 | ||
827 | static inline | |
828 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
829 | ||
830 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
831 | ||
832 | static inline | |
833 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
834 | { | |
835 | int prio = rt_se_prio(rt_se); | |
836 | ||
837 | WARN_ON(!rt_prio(prio)); | |
838 | rt_rq->rt_nr_running++; | |
839 | ||
840 | inc_rt_prio(rt_rq, prio); | |
841 | inc_rt_migration(rt_se, rt_rq); | |
842 | inc_rt_group(rt_se, rt_rq); | |
843 | } | |
844 | ||
845 | static inline | |
846 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
847 | { | |
848 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
849 | WARN_ON(!rt_rq->rt_nr_running); | |
850 | rt_rq->rt_nr_running--; | |
851 | ||
852 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
853 | dec_rt_migration(rt_se, rt_rq); | |
854 | dec_rt_group(rt_se, rt_rq); | |
63489e45 SR |
855 | } |
856 | ||
37dad3fc | 857 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head) |
bb44e5d1 | 858 | { |
6f505b16 PZ |
859 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
860 | struct rt_prio_array *array = &rt_rq->active; | |
861 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 862 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 863 | |
ad2a3f13 PZ |
864 | /* |
865 | * Don't enqueue the group if its throttled, or when empty. | |
866 | * The latter is a consequence of the former when a child group | |
867 | * get throttled and the current group doesn't have any other | |
868 | * active members. | |
869 | */ | |
870 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) | |
6f505b16 | 871 | return; |
63489e45 | 872 | |
3d4b47b4 PZ |
873 | if (!rt_rq->rt_nr_running) |
874 | list_add_leaf_rt_rq(rt_rq); | |
875 | ||
37dad3fc TG |
876 | if (head) |
877 | list_add(&rt_se->run_list, queue); | |
878 | else | |
879 | list_add_tail(&rt_se->run_list, queue); | |
6f505b16 | 880 | __set_bit(rt_se_prio(rt_se), array->bitmap); |
78f2c7db | 881 | |
6f505b16 PZ |
882 | inc_rt_tasks(rt_se, rt_rq); |
883 | } | |
884 | ||
ad2a3f13 | 885 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) |
6f505b16 PZ |
886 | { |
887 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
888 | struct rt_prio_array *array = &rt_rq->active; | |
889 | ||
890 | list_del_init(&rt_se->run_list); | |
891 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
892 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
893 | ||
894 | dec_rt_tasks(rt_se, rt_rq); | |
3d4b47b4 PZ |
895 | if (!rt_rq->rt_nr_running) |
896 | list_del_leaf_rt_rq(rt_rq); | |
6f505b16 PZ |
897 | } |
898 | ||
899 | /* | |
900 | * Because the prio of an upper entry depends on the lower | |
901 | * entries, we must remove entries top - down. | |
6f505b16 | 902 | */ |
ad2a3f13 | 903 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se) |
6f505b16 | 904 | { |
ad2a3f13 | 905 | struct sched_rt_entity *back = NULL; |
6f505b16 | 906 | |
58d6c2d7 PZ |
907 | for_each_sched_rt_entity(rt_se) { |
908 | rt_se->back = back; | |
909 | back = rt_se; | |
910 | } | |
911 | ||
912 | for (rt_se = back; rt_se; rt_se = rt_se->back) { | |
913 | if (on_rt_rq(rt_se)) | |
ad2a3f13 PZ |
914 | __dequeue_rt_entity(rt_se); |
915 | } | |
916 | } | |
917 | ||
37dad3fc | 918 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head) |
ad2a3f13 PZ |
919 | { |
920 | dequeue_rt_stack(rt_se); | |
921 | for_each_sched_rt_entity(rt_se) | |
37dad3fc | 922 | __enqueue_rt_entity(rt_se, head); |
ad2a3f13 PZ |
923 | } |
924 | ||
925 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se) | |
926 | { | |
927 | dequeue_rt_stack(rt_se); | |
928 | ||
929 | for_each_sched_rt_entity(rt_se) { | |
930 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
931 | ||
932 | if (rt_rq && rt_rq->rt_nr_running) | |
37dad3fc | 933 | __enqueue_rt_entity(rt_se, false); |
58d6c2d7 | 934 | } |
bb44e5d1 IM |
935 | } |
936 | ||
937 | /* | |
938 | * Adding/removing a task to/from a priority array: | |
939 | */ | |
ea87bb78 | 940 | static void |
371fd7e7 | 941 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
6f505b16 PZ |
942 | { |
943 | struct sched_rt_entity *rt_se = &p->rt; | |
944 | ||
371fd7e7 | 945 | if (flags & ENQUEUE_WAKEUP) |
6f505b16 PZ |
946 | rt_se->timeout = 0; |
947 | ||
371fd7e7 | 948 | enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD); |
c09595f6 | 949 | |
917b627d GH |
950 | if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) |
951 | enqueue_pushable_task(rq, p); | |
6f505b16 PZ |
952 | } |
953 | ||
371fd7e7 | 954 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 955 | { |
6f505b16 | 956 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 957 | |
f1e14ef6 | 958 | update_curr_rt(rq); |
ad2a3f13 | 959 | dequeue_rt_entity(rt_se); |
c09595f6 | 960 | |
917b627d | 961 | dequeue_pushable_task(rq, p); |
bb44e5d1 IM |
962 | } |
963 | ||
964 | /* | |
965 | * Put task to the end of the run list without the overhead of dequeue | |
966 | * followed by enqueue. | |
967 | */ | |
7ebefa8c DA |
968 | static void |
969 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 970 | { |
1cdad715 | 971 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
972 | struct rt_prio_array *array = &rt_rq->active; |
973 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
974 | ||
975 | if (head) | |
976 | list_move(&rt_se->run_list, queue); | |
977 | else | |
978 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 979 | } |
6f505b16 PZ |
980 | } |
981 | ||
7ebefa8c | 982 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 983 | { |
6f505b16 PZ |
984 | struct sched_rt_entity *rt_se = &p->rt; |
985 | struct rt_rq *rt_rq; | |
bb44e5d1 | 986 | |
6f505b16 PZ |
987 | for_each_sched_rt_entity(rt_se) { |
988 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 989 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 990 | } |
bb44e5d1 IM |
991 | } |
992 | ||
6f505b16 | 993 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 994 | { |
7ebefa8c | 995 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
996 | } |
997 | ||
e7693a36 | 998 | #ifdef CONFIG_SMP |
318e0893 GH |
999 | static int find_lowest_rq(struct task_struct *task); |
1000 | ||
0017d735 | 1001 | static int |
7608dec2 | 1002 | select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) |
e7693a36 | 1003 | { |
7608dec2 PZ |
1004 | struct task_struct *curr; |
1005 | struct rq *rq; | |
1006 | int cpu; | |
1007 | ||
0763a660 | 1008 | if (sd_flag != SD_BALANCE_WAKE) |
5f3edc1b PZ |
1009 | return smp_processor_id(); |
1010 | ||
7608dec2 PZ |
1011 | cpu = task_cpu(p); |
1012 | rq = cpu_rq(cpu); | |
1013 | ||
1014 | rcu_read_lock(); | |
1015 | curr = ACCESS_ONCE(rq->curr); /* unlocked access */ | |
1016 | ||
318e0893 | 1017 | /* |
7608dec2 | 1018 | * If the current task on @p's runqueue is an RT task, then |
e1f47d89 SR |
1019 | * try to see if we can wake this RT task up on another |
1020 | * runqueue. Otherwise simply start this RT task | |
1021 | * on its current runqueue. | |
1022 | * | |
43fa5460 SR |
1023 | * We want to avoid overloading runqueues. If the woken |
1024 | * task is a higher priority, then it will stay on this CPU | |
1025 | * and the lower prio task should be moved to another CPU. | |
1026 | * Even though this will probably make the lower prio task | |
1027 | * lose its cache, we do not want to bounce a higher task | |
1028 | * around just because it gave up its CPU, perhaps for a | |
1029 | * lock? | |
1030 | * | |
1031 | * For equal prio tasks, we just let the scheduler sort it out. | |
7608dec2 PZ |
1032 | * |
1033 | * Otherwise, just let it ride on the affined RQ and the | |
1034 | * post-schedule router will push the preempted task away | |
1035 | * | |
1036 | * This test is optimistic, if we get it wrong the load-balancer | |
1037 | * will have to sort it out. | |
318e0893 | 1038 | */ |
7608dec2 PZ |
1039 | if (curr && unlikely(rt_task(curr)) && |
1040 | (curr->rt.nr_cpus_allowed < 2 || | |
1041 | curr->prio < p->prio) && | |
6f505b16 | 1042 | (p->rt.nr_cpus_allowed > 1)) { |
7608dec2 | 1043 | int target = find_lowest_rq(p); |
318e0893 | 1044 | |
7608dec2 PZ |
1045 | if (target != -1) |
1046 | cpu = target; | |
318e0893 | 1047 | } |
7608dec2 | 1048 | rcu_read_unlock(); |
318e0893 | 1049 | |
7608dec2 | 1050 | return cpu; |
e7693a36 | 1051 | } |
7ebefa8c DA |
1052 | |
1053 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1054 | { | |
7ebefa8c DA |
1055 | if (rq->curr->rt.nr_cpus_allowed == 1) |
1056 | return; | |
1057 | ||
24600ce8 | 1058 | if (p->rt.nr_cpus_allowed != 1 |
13b8bd0a RR |
1059 | && cpupri_find(&rq->rd->cpupri, p, NULL)) |
1060 | return; | |
24600ce8 | 1061 | |
13b8bd0a RR |
1062 | if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) |
1063 | return; | |
7ebefa8c DA |
1064 | |
1065 | /* | |
1066 | * There appears to be other cpus that can accept | |
1067 | * current and none to run 'p', so lets reschedule | |
1068 | * to try and push current away: | |
1069 | */ | |
1070 | requeue_task_rt(rq, p, 1); | |
1071 | resched_task(rq->curr); | |
1072 | } | |
1073 | ||
e7693a36 GH |
1074 | #endif /* CONFIG_SMP */ |
1075 | ||
bb44e5d1 IM |
1076 | /* |
1077 | * Preempt the current task with a newly woken task if needed: | |
1078 | */ | |
7d478721 | 1079 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1080 | { |
45c01e82 | 1081 | if (p->prio < rq->curr->prio) { |
bb44e5d1 | 1082 | resched_task(rq->curr); |
45c01e82 GH |
1083 | return; |
1084 | } | |
1085 | ||
1086 | #ifdef CONFIG_SMP | |
1087 | /* | |
1088 | * If: | |
1089 | * | |
1090 | * - the newly woken task is of equal priority to the current task | |
1091 | * - the newly woken task is non-migratable while current is migratable | |
1092 | * - current will be preempted on the next reschedule | |
1093 | * | |
1094 | * we should check to see if current can readily move to a different | |
1095 | * cpu. If so, we will reschedule to allow the push logic to try | |
1096 | * to move current somewhere else, making room for our non-migratable | |
1097 | * task. | |
1098 | */ | |
7ebefa8c DA |
1099 | if (p->prio == rq->curr->prio && !need_resched()) |
1100 | check_preempt_equal_prio(rq, p); | |
45c01e82 | 1101 | #endif |
bb44e5d1 IM |
1102 | } |
1103 | ||
6f505b16 PZ |
1104 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
1105 | struct rt_rq *rt_rq) | |
bb44e5d1 | 1106 | { |
6f505b16 PZ |
1107 | struct rt_prio_array *array = &rt_rq->active; |
1108 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1109 | struct list_head *queue; |
1110 | int idx; | |
1111 | ||
1112 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1113 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1114 | |
1115 | queue = array->queue + idx; | |
6f505b16 | 1116 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1117 | |
6f505b16 PZ |
1118 | return next; |
1119 | } | |
bb44e5d1 | 1120 | |
917b627d | 1121 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1122 | { |
1123 | struct sched_rt_entity *rt_se; | |
1124 | struct task_struct *p; | |
1125 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1126 | |
6f505b16 PZ |
1127 | rt_rq = &rq->rt; |
1128 | ||
1129 | if (unlikely(!rt_rq->rt_nr_running)) | |
1130 | return NULL; | |
1131 | ||
23b0fdfc | 1132 | if (rt_rq_throttled(rt_rq)) |
6f505b16 PZ |
1133 | return NULL; |
1134 | ||
1135 | do { | |
1136 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
326587b8 | 1137 | BUG_ON(!rt_se); |
6f505b16 PZ |
1138 | rt_rq = group_rt_rq(rt_se); |
1139 | } while (rt_rq); | |
1140 | ||
1141 | p = rt_task_of(rt_se); | |
305e6835 | 1142 | p->se.exec_start = rq->clock_task; |
917b627d GH |
1143 | |
1144 | return p; | |
1145 | } | |
1146 | ||
1147 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
1148 | { | |
1149 | struct task_struct *p = _pick_next_task_rt(rq); | |
1150 | ||
1151 | /* The running task is never eligible for pushing */ | |
1152 | if (p) | |
1153 | dequeue_pushable_task(rq, p); | |
1154 | ||
bcf08df3 | 1155 | #ifdef CONFIG_SMP |
3f029d3c GH |
1156 | /* |
1157 | * We detect this state here so that we can avoid taking the RQ | |
1158 | * lock again later if there is no need to push | |
1159 | */ | |
1160 | rq->post_schedule = has_pushable_tasks(rq); | |
bcf08df3 | 1161 | #endif |
3f029d3c | 1162 | |
6f505b16 | 1163 | return p; |
bb44e5d1 IM |
1164 | } |
1165 | ||
31ee529c | 1166 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1167 | { |
f1e14ef6 | 1168 | update_curr_rt(rq); |
bb44e5d1 | 1169 | p->se.exec_start = 0; |
917b627d GH |
1170 | |
1171 | /* | |
1172 | * The previous task needs to be made eligible for pushing | |
1173 | * if it is still active | |
1174 | */ | |
fd2f4419 | 1175 | if (on_rt_rq(&p->rt) && p->rt.nr_cpus_allowed > 1) |
917b627d | 1176 | enqueue_pushable_task(rq, p); |
bb44e5d1 IM |
1177 | } |
1178 | ||
681f3e68 | 1179 | #ifdef CONFIG_SMP |
6f505b16 | 1180 | |
e8fa1362 SR |
1181 | /* Only try algorithms three times */ |
1182 | #define RT_MAX_TRIES 3 | |
1183 | ||
e8fa1362 SR |
1184 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); |
1185 | ||
f65eda4f SR |
1186 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1187 | { | |
1188 | if (!task_running(rq, p) && | |
96f874e2 | 1189 | (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) && |
6f505b16 | 1190 | (p->rt.nr_cpus_allowed > 1)) |
f65eda4f SR |
1191 | return 1; |
1192 | return 0; | |
1193 | } | |
1194 | ||
e8fa1362 | 1195 | /* Return the second highest RT task, NULL otherwise */ |
79064fbf | 1196 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) |
e8fa1362 | 1197 | { |
6f505b16 PZ |
1198 | struct task_struct *next = NULL; |
1199 | struct sched_rt_entity *rt_se; | |
1200 | struct rt_prio_array *array; | |
1201 | struct rt_rq *rt_rq; | |
e8fa1362 SR |
1202 | int idx; |
1203 | ||
6f505b16 PZ |
1204 | for_each_leaf_rt_rq(rt_rq, rq) { |
1205 | array = &rt_rq->active; | |
1206 | idx = sched_find_first_bit(array->bitmap); | |
49246274 | 1207 | next_idx: |
6f505b16 PZ |
1208 | if (idx >= MAX_RT_PRIO) |
1209 | continue; | |
1210 | if (next && next->prio < idx) | |
1211 | continue; | |
1212 | list_for_each_entry(rt_se, array->queue + idx, run_list) { | |
3d07467b PZ |
1213 | struct task_struct *p; |
1214 | ||
1215 | if (!rt_entity_is_task(rt_se)) | |
1216 | continue; | |
1217 | ||
1218 | p = rt_task_of(rt_se); | |
6f505b16 PZ |
1219 | if (pick_rt_task(rq, p, cpu)) { |
1220 | next = p; | |
1221 | break; | |
1222 | } | |
1223 | } | |
1224 | if (!next) { | |
1225 | idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); | |
1226 | goto next_idx; | |
1227 | } | |
f65eda4f SR |
1228 | } |
1229 | ||
e8fa1362 SR |
1230 | return next; |
1231 | } | |
1232 | ||
0e3900e6 | 1233 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1234 | |
6e1254d2 GH |
1235 | static int find_lowest_rq(struct task_struct *task) |
1236 | { | |
1237 | struct sched_domain *sd; | |
96f874e2 | 1238 | struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); |
6e1254d2 GH |
1239 | int this_cpu = smp_processor_id(); |
1240 | int cpu = task_cpu(task); | |
06f90dbd | 1241 | |
6e0534f2 GH |
1242 | if (task->rt.nr_cpus_allowed == 1) |
1243 | return -1; /* No other targets possible */ | |
6e1254d2 | 1244 | |
6e0534f2 GH |
1245 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
1246 | return -1; /* No targets found */ | |
6e1254d2 GH |
1247 | |
1248 | /* | |
1249 | * At this point we have built a mask of cpus representing the | |
1250 | * lowest priority tasks in the system. Now we want to elect | |
1251 | * the best one based on our affinity and topology. | |
1252 | * | |
1253 | * We prioritize the last cpu that the task executed on since | |
1254 | * it is most likely cache-hot in that location. | |
1255 | */ | |
96f874e2 | 1256 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1257 | return cpu; |
1258 | ||
1259 | /* | |
1260 | * Otherwise, we consult the sched_domains span maps to figure | |
1261 | * out which cpu is logically closest to our hot cache data. | |
1262 | */ | |
e2c88063 RR |
1263 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) |
1264 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
6e1254d2 | 1265 | |
e2c88063 RR |
1266 | for_each_domain(cpu, sd) { |
1267 | if (sd->flags & SD_WAKE_AFFINE) { | |
1268 | int best_cpu; | |
6e1254d2 | 1269 | |
e2c88063 RR |
1270 | /* |
1271 | * "this_cpu" is cheaper to preempt than a | |
1272 | * remote processor. | |
1273 | */ | |
1274 | if (this_cpu != -1 && | |
1275 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) | |
1276 | return this_cpu; | |
1277 | ||
1278 | best_cpu = cpumask_first_and(lowest_mask, | |
1279 | sched_domain_span(sd)); | |
1280 | if (best_cpu < nr_cpu_ids) | |
1281 | return best_cpu; | |
6e1254d2 GH |
1282 | } |
1283 | } | |
1284 | ||
1285 | /* | |
1286 | * And finally, if there were no matches within the domains | |
1287 | * just give the caller *something* to work with from the compatible | |
1288 | * locations. | |
1289 | */ | |
e2c88063 RR |
1290 | if (this_cpu != -1) |
1291 | return this_cpu; | |
1292 | ||
1293 | cpu = cpumask_any(lowest_mask); | |
1294 | if (cpu < nr_cpu_ids) | |
1295 | return cpu; | |
1296 | return -1; | |
07b4032c GH |
1297 | } |
1298 | ||
1299 | /* Will lock the rq it finds */ | |
4df64c0b | 1300 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1301 | { |
1302 | struct rq *lowest_rq = NULL; | |
07b4032c | 1303 | int tries; |
4df64c0b | 1304 | int cpu; |
e8fa1362 | 1305 | |
07b4032c GH |
1306 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1307 | cpu = find_lowest_rq(task); | |
1308 | ||
2de0b463 | 1309 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1310 | break; |
1311 | ||
07b4032c GH |
1312 | lowest_rq = cpu_rq(cpu); |
1313 | ||
e8fa1362 | 1314 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1315 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1316 | /* |
1317 | * We had to unlock the run queue. In | |
1318 | * the mean time, task could have | |
1319 | * migrated already or had its affinity changed. | |
1320 | * Also make sure that it wasn't scheduled on its rq. | |
1321 | */ | |
07b4032c | 1322 | if (unlikely(task_rq(task) != rq || |
96f874e2 RR |
1323 | !cpumask_test_cpu(lowest_rq->cpu, |
1324 | &task->cpus_allowed) || | |
07b4032c | 1325 | task_running(rq, task) || |
fd2f4419 | 1326 | !task->on_rq)) { |
4df64c0b | 1327 | |
05fa785c | 1328 | raw_spin_unlock(&lowest_rq->lock); |
e8fa1362 SR |
1329 | lowest_rq = NULL; |
1330 | break; | |
1331 | } | |
1332 | } | |
1333 | ||
1334 | /* If this rq is still suitable use it. */ | |
e864c499 | 1335 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1336 | break; |
1337 | ||
1338 | /* try again */ | |
1b12bbc7 | 1339 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1340 | lowest_rq = NULL; |
1341 | } | |
1342 | ||
1343 | return lowest_rq; | |
1344 | } | |
1345 | ||
917b627d GH |
1346 | static struct task_struct *pick_next_pushable_task(struct rq *rq) |
1347 | { | |
1348 | struct task_struct *p; | |
1349 | ||
1350 | if (!has_pushable_tasks(rq)) | |
1351 | return NULL; | |
1352 | ||
1353 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1354 | struct task_struct, pushable_tasks); | |
1355 | ||
1356 | BUG_ON(rq->cpu != task_cpu(p)); | |
1357 | BUG_ON(task_current(rq, p)); | |
1358 | BUG_ON(p->rt.nr_cpus_allowed <= 1); | |
1359 | ||
fd2f4419 | 1360 | BUG_ON(!p->on_rq); |
917b627d GH |
1361 | BUG_ON(!rt_task(p)); |
1362 | ||
1363 | return p; | |
1364 | } | |
1365 | ||
e8fa1362 SR |
1366 | /* |
1367 | * If the current CPU has more than one RT task, see if the non | |
1368 | * running task can migrate over to a CPU that is running a task | |
1369 | * of lesser priority. | |
1370 | */ | |
697f0a48 | 1371 | static int push_rt_task(struct rq *rq) |
e8fa1362 SR |
1372 | { |
1373 | struct task_struct *next_task; | |
1374 | struct rq *lowest_rq; | |
e8fa1362 | 1375 | |
a22d7fc1 GH |
1376 | if (!rq->rt.overloaded) |
1377 | return 0; | |
1378 | ||
917b627d | 1379 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
1380 | if (!next_task) |
1381 | return 0; | |
1382 | ||
49246274 | 1383 | retry: |
697f0a48 | 1384 | if (unlikely(next_task == rq->curr)) { |
f65eda4f | 1385 | WARN_ON(1); |
e8fa1362 | 1386 | return 0; |
f65eda4f | 1387 | } |
e8fa1362 SR |
1388 | |
1389 | /* | |
1390 | * It's possible that the next_task slipped in of | |
1391 | * higher priority than current. If that's the case | |
1392 | * just reschedule current. | |
1393 | */ | |
697f0a48 GH |
1394 | if (unlikely(next_task->prio < rq->curr->prio)) { |
1395 | resched_task(rq->curr); | |
e8fa1362 SR |
1396 | return 0; |
1397 | } | |
1398 | ||
697f0a48 | 1399 | /* We might release rq lock */ |
e8fa1362 SR |
1400 | get_task_struct(next_task); |
1401 | ||
1402 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 1403 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
1404 | if (!lowest_rq) { |
1405 | struct task_struct *task; | |
1406 | /* | |
697f0a48 | 1407 | * find lock_lowest_rq releases rq->lock |
1563513d GH |
1408 | * so it is possible that next_task has migrated. |
1409 | * | |
1410 | * We need to make sure that the task is still on the same | |
1411 | * run-queue and is also still the next task eligible for | |
1412 | * pushing. | |
e8fa1362 | 1413 | */ |
917b627d | 1414 | task = pick_next_pushable_task(rq); |
1563513d GH |
1415 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
1416 | /* | |
25985edc | 1417 | * If we get here, the task hasn't moved at all, but |
1563513d GH |
1418 | * it has failed to push. We will not try again, |
1419 | * since the other cpus will pull from us when they | |
1420 | * are ready. | |
1421 | */ | |
1422 | dequeue_pushable_task(rq, next_task); | |
1423 | goto out; | |
e8fa1362 | 1424 | } |
917b627d | 1425 | |
1563513d GH |
1426 | if (!task) |
1427 | /* No more tasks, just exit */ | |
1428 | goto out; | |
1429 | ||
917b627d | 1430 | /* |
1563513d | 1431 | * Something has shifted, try again. |
917b627d | 1432 | */ |
1563513d GH |
1433 | put_task_struct(next_task); |
1434 | next_task = task; | |
1435 | goto retry; | |
e8fa1362 SR |
1436 | } |
1437 | ||
697f0a48 | 1438 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
1439 | set_task_cpu(next_task, lowest_rq->cpu); |
1440 | activate_task(lowest_rq, next_task, 0); | |
1441 | ||
1442 | resched_task(lowest_rq->curr); | |
1443 | ||
1b12bbc7 | 1444 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 | 1445 | |
e8fa1362 SR |
1446 | out: |
1447 | put_task_struct(next_task); | |
1448 | ||
917b627d | 1449 | return 1; |
e8fa1362 SR |
1450 | } |
1451 | ||
e8fa1362 SR |
1452 | static void push_rt_tasks(struct rq *rq) |
1453 | { | |
1454 | /* push_rt_task will return true if it moved an RT */ | |
1455 | while (push_rt_task(rq)) | |
1456 | ; | |
1457 | } | |
1458 | ||
f65eda4f SR |
1459 | static int pull_rt_task(struct rq *this_rq) |
1460 | { | |
80bf3171 | 1461 | int this_cpu = this_rq->cpu, ret = 0, cpu; |
a8728944 | 1462 | struct task_struct *p; |
f65eda4f | 1463 | struct rq *src_rq; |
f65eda4f | 1464 | |
637f5085 | 1465 | if (likely(!rt_overloaded(this_rq))) |
f65eda4f SR |
1466 | return 0; |
1467 | ||
c6c4927b | 1468 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
1469 | if (this_cpu == cpu) |
1470 | continue; | |
1471 | ||
1472 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
1473 | |
1474 | /* | |
1475 | * Don't bother taking the src_rq->lock if the next highest | |
1476 | * task is known to be lower-priority than our current task. | |
1477 | * This may look racy, but if this value is about to go | |
1478 | * logically higher, the src_rq will push this task away. | |
1479 | * And if its going logically lower, we do not care | |
1480 | */ | |
1481 | if (src_rq->rt.highest_prio.next >= | |
1482 | this_rq->rt.highest_prio.curr) | |
1483 | continue; | |
1484 | ||
f65eda4f SR |
1485 | /* |
1486 | * We can potentially drop this_rq's lock in | |
1487 | * double_lock_balance, and another CPU could | |
a8728944 | 1488 | * alter this_rq |
f65eda4f | 1489 | */ |
a8728944 | 1490 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
1491 | |
1492 | /* | |
1493 | * Are there still pullable RT tasks? | |
1494 | */ | |
614ee1f6 MG |
1495 | if (src_rq->rt.rt_nr_running <= 1) |
1496 | goto skip; | |
f65eda4f | 1497 | |
f65eda4f SR |
1498 | p = pick_next_highest_task_rt(src_rq, this_cpu); |
1499 | ||
1500 | /* | |
1501 | * Do we have an RT task that preempts | |
1502 | * the to-be-scheduled task? | |
1503 | */ | |
a8728944 | 1504 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f | 1505 | WARN_ON(p == src_rq->curr); |
fd2f4419 | 1506 | WARN_ON(!p->on_rq); |
f65eda4f SR |
1507 | |
1508 | /* | |
1509 | * There's a chance that p is higher in priority | |
1510 | * than what's currently running on its cpu. | |
1511 | * This is just that p is wakeing up and hasn't | |
1512 | * had a chance to schedule. We only pull | |
1513 | * p if it is lower in priority than the | |
a8728944 | 1514 | * current task on the run queue |
f65eda4f | 1515 | */ |
a8728944 | 1516 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 1517 | goto skip; |
f65eda4f SR |
1518 | |
1519 | ret = 1; | |
1520 | ||
1521 | deactivate_task(src_rq, p, 0); | |
1522 | set_task_cpu(p, this_cpu); | |
1523 | activate_task(this_rq, p, 0); | |
1524 | /* | |
1525 | * We continue with the search, just in | |
1526 | * case there's an even higher prio task | |
25985edc | 1527 | * in another runqueue. (low likelihood |
f65eda4f | 1528 | * but possible) |
f65eda4f | 1529 | */ |
f65eda4f | 1530 | } |
49246274 | 1531 | skip: |
1b12bbc7 | 1532 | double_unlock_balance(this_rq, src_rq); |
f65eda4f SR |
1533 | } |
1534 | ||
1535 | return ret; | |
1536 | } | |
1537 | ||
9a897c5a | 1538 | static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) |
f65eda4f SR |
1539 | { |
1540 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
e864c499 | 1541 | if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio) |
f65eda4f SR |
1542 | pull_rt_task(rq); |
1543 | } | |
1544 | ||
9a897c5a | 1545 | static void post_schedule_rt(struct rq *rq) |
e8fa1362 | 1546 | { |
967fc046 | 1547 | push_rt_tasks(rq); |
e8fa1362 SR |
1548 | } |
1549 | ||
8ae121ac GH |
1550 | /* |
1551 | * If we are not running and we are not going to reschedule soon, we should | |
1552 | * try to push tasks away now | |
1553 | */ | |
efbbd05a | 1554 | static void task_woken_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 1555 | { |
9a897c5a | 1556 | if (!task_running(rq, p) && |
8ae121ac | 1557 | !test_tsk_need_resched(rq->curr) && |
917b627d | 1558 | has_pushable_tasks(rq) && |
b3bc211c | 1559 | p->rt.nr_cpus_allowed > 1 && |
43fa5460 | 1560 | rt_task(rq->curr) && |
b3bc211c SR |
1561 | (rq->curr->rt.nr_cpus_allowed < 2 || |
1562 | rq->curr->prio < p->prio)) | |
4642dafd SR |
1563 | push_rt_tasks(rq); |
1564 | } | |
1565 | ||
cd8ba7cd | 1566 | static void set_cpus_allowed_rt(struct task_struct *p, |
96f874e2 | 1567 | const struct cpumask *new_mask) |
73fe6aae | 1568 | { |
96f874e2 | 1569 | int weight = cpumask_weight(new_mask); |
73fe6aae GH |
1570 | |
1571 | BUG_ON(!rt_task(p)); | |
1572 | ||
1573 | /* | |
1574 | * Update the migration status of the RQ if we have an RT task | |
1575 | * which is running AND changing its weight value. | |
1576 | */ | |
fd2f4419 | 1577 | if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) { |
73fe6aae GH |
1578 | struct rq *rq = task_rq(p); |
1579 | ||
917b627d GH |
1580 | if (!task_current(rq, p)) { |
1581 | /* | |
1582 | * Make sure we dequeue this task from the pushable list | |
1583 | * before going further. It will either remain off of | |
1584 | * the list because we are no longer pushable, or it | |
1585 | * will be requeued. | |
1586 | */ | |
1587 | if (p->rt.nr_cpus_allowed > 1) | |
1588 | dequeue_pushable_task(rq, p); | |
1589 | ||
1590 | /* | |
1591 | * Requeue if our weight is changing and still > 1 | |
1592 | */ | |
1593 | if (weight > 1) | |
1594 | enqueue_pushable_task(rq, p); | |
1595 | ||
1596 | } | |
1597 | ||
6f505b16 | 1598 | if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { |
73fe6aae | 1599 | rq->rt.rt_nr_migratory++; |
6f505b16 | 1600 | } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { |
73fe6aae GH |
1601 | BUG_ON(!rq->rt.rt_nr_migratory); |
1602 | rq->rt.rt_nr_migratory--; | |
1603 | } | |
1604 | ||
398a153b | 1605 | update_rt_migration(&rq->rt); |
73fe6aae GH |
1606 | } |
1607 | ||
96f874e2 | 1608 | cpumask_copy(&p->cpus_allowed, new_mask); |
6f505b16 | 1609 | p->rt.nr_cpus_allowed = weight; |
73fe6aae | 1610 | } |
deeeccd4 | 1611 | |
bdd7c81b | 1612 | /* Assumes rq->lock is held */ |
1f11eb6a | 1613 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
1614 | { |
1615 | if (rq->rt.overloaded) | |
1616 | rt_set_overload(rq); | |
6e0534f2 | 1617 | |
7def2be1 PZ |
1618 | __enable_runtime(rq); |
1619 | ||
e864c499 | 1620 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
1621 | } |
1622 | ||
1623 | /* Assumes rq->lock is held */ | |
1f11eb6a | 1624 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
1625 | { |
1626 | if (rq->rt.overloaded) | |
1627 | rt_clear_overload(rq); | |
6e0534f2 | 1628 | |
7def2be1 PZ |
1629 | __disable_runtime(rq); |
1630 | ||
6e0534f2 | 1631 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 1632 | } |
cb469845 SR |
1633 | |
1634 | /* | |
1635 | * When switch from the rt queue, we bring ourselves to a position | |
1636 | * that we might want to pull RT tasks from other runqueues. | |
1637 | */ | |
da7a735e | 1638 | static void switched_from_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
1639 | { |
1640 | /* | |
1641 | * If there are other RT tasks then we will reschedule | |
1642 | * and the scheduling of the other RT tasks will handle | |
1643 | * the balancing. But if we are the last RT task | |
1644 | * we may need to handle the pulling of RT tasks | |
1645 | * now. | |
1646 | */ | |
fd2f4419 | 1647 | if (p->on_rq && !rq->rt.rt_nr_running) |
cb469845 SR |
1648 | pull_rt_task(rq); |
1649 | } | |
3d8cbdf8 RR |
1650 | |
1651 | static inline void init_sched_rt_class(void) | |
1652 | { | |
1653 | unsigned int i; | |
1654 | ||
1655 | for_each_possible_cpu(i) | |
eaa95840 | 1656 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
6ca09dfc | 1657 | GFP_KERNEL, cpu_to_node(i)); |
3d8cbdf8 | 1658 | } |
cb469845 SR |
1659 | #endif /* CONFIG_SMP */ |
1660 | ||
1661 | /* | |
1662 | * When switching a task to RT, we may overload the runqueue | |
1663 | * with RT tasks. In this case we try to push them off to | |
1664 | * other runqueues. | |
1665 | */ | |
da7a735e | 1666 | static void switched_to_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
1667 | { |
1668 | int check_resched = 1; | |
1669 | ||
1670 | /* | |
1671 | * If we are already running, then there's nothing | |
1672 | * that needs to be done. But if we are not running | |
1673 | * we may need to preempt the current running task. | |
1674 | * If that current running task is also an RT task | |
1675 | * then see if we can move to another run queue. | |
1676 | */ | |
fd2f4419 | 1677 | if (p->on_rq && rq->curr != p) { |
cb469845 SR |
1678 | #ifdef CONFIG_SMP |
1679 | if (rq->rt.overloaded && push_rt_task(rq) && | |
1680 | /* Don't resched if we changed runqueues */ | |
1681 | rq != task_rq(p)) | |
1682 | check_resched = 0; | |
1683 | #endif /* CONFIG_SMP */ | |
1684 | if (check_resched && p->prio < rq->curr->prio) | |
1685 | resched_task(rq->curr); | |
1686 | } | |
1687 | } | |
1688 | ||
1689 | /* | |
1690 | * Priority of the task has changed. This may cause | |
1691 | * us to initiate a push or pull. | |
1692 | */ | |
da7a735e PZ |
1693 | static void |
1694 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 1695 | { |
fd2f4419 | 1696 | if (!p->on_rq) |
da7a735e PZ |
1697 | return; |
1698 | ||
1699 | if (rq->curr == p) { | |
cb469845 SR |
1700 | #ifdef CONFIG_SMP |
1701 | /* | |
1702 | * If our priority decreases while running, we | |
1703 | * may need to pull tasks to this runqueue. | |
1704 | */ | |
1705 | if (oldprio < p->prio) | |
1706 | pull_rt_task(rq); | |
1707 | /* | |
1708 | * If there's a higher priority task waiting to run | |
6fa46fa5 SR |
1709 | * then reschedule. Note, the above pull_rt_task |
1710 | * can release the rq lock and p could migrate. | |
1711 | * Only reschedule if p is still on the same runqueue. | |
cb469845 | 1712 | */ |
e864c499 | 1713 | if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) |
cb469845 SR |
1714 | resched_task(p); |
1715 | #else | |
1716 | /* For UP simply resched on drop of prio */ | |
1717 | if (oldprio < p->prio) | |
1718 | resched_task(p); | |
e8fa1362 | 1719 | #endif /* CONFIG_SMP */ |
cb469845 SR |
1720 | } else { |
1721 | /* | |
1722 | * This task is not running, but if it is | |
1723 | * greater than the current running task | |
1724 | * then reschedule. | |
1725 | */ | |
1726 | if (p->prio < rq->curr->prio) | |
1727 | resched_task(rq->curr); | |
1728 | } | |
1729 | } | |
1730 | ||
78f2c7db PZ |
1731 | static void watchdog(struct rq *rq, struct task_struct *p) |
1732 | { | |
1733 | unsigned long soft, hard; | |
1734 | ||
78d7d407 JS |
1735 | /* max may change after cur was read, this will be fixed next tick */ |
1736 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
1737 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
78f2c7db PZ |
1738 | |
1739 | if (soft != RLIM_INFINITY) { | |
1740 | unsigned long next; | |
1741 | ||
1742 | p->rt.timeout++; | |
1743 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); | |
5a52dd50 | 1744 | if (p->rt.timeout > next) |
f06febc9 | 1745 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
78f2c7db PZ |
1746 | } |
1747 | } | |
bb44e5d1 | 1748 | |
8f4d37ec | 1749 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 1750 | { |
67e2be02 PZ |
1751 | update_curr_rt(rq); |
1752 | ||
78f2c7db PZ |
1753 | watchdog(rq, p); |
1754 | ||
bb44e5d1 IM |
1755 | /* |
1756 | * RR tasks need a special form of timeslice management. | |
1757 | * FIFO tasks have no timeslices. | |
1758 | */ | |
1759 | if (p->policy != SCHED_RR) | |
1760 | return; | |
1761 | ||
fa717060 | 1762 | if (--p->rt.time_slice) |
bb44e5d1 IM |
1763 | return; |
1764 | ||
fa717060 | 1765 | p->rt.time_slice = DEF_TIMESLICE; |
bb44e5d1 | 1766 | |
98fbc798 DA |
1767 | /* |
1768 | * Requeue to the end of queue if we are not the only element | |
1769 | * on the queue: | |
1770 | */ | |
fa717060 | 1771 | if (p->rt.run_list.prev != p->rt.run_list.next) { |
7ebefa8c | 1772 | requeue_task_rt(rq, p, 0); |
98fbc798 DA |
1773 | set_tsk_need_resched(p); |
1774 | } | |
bb44e5d1 IM |
1775 | } |
1776 | ||
83b699ed SV |
1777 | static void set_curr_task_rt(struct rq *rq) |
1778 | { | |
1779 | struct task_struct *p = rq->curr; | |
1780 | ||
305e6835 | 1781 | p->se.exec_start = rq->clock_task; |
917b627d GH |
1782 | |
1783 | /* The running task is never eligible for pushing */ | |
1784 | dequeue_pushable_task(rq, p); | |
83b699ed SV |
1785 | } |
1786 | ||
6d686f45 | 1787 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) |
0d721cea PW |
1788 | { |
1789 | /* | |
1790 | * Time slice is 0 for SCHED_FIFO tasks | |
1791 | */ | |
1792 | if (task->policy == SCHED_RR) | |
1793 | return DEF_TIMESLICE; | |
1794 | else | |
1795 | return 0; | |
1796 | } | |
1797 | ||
2abdad0a | 1798 | static const struct sched_class rt_sched_class = { |
5522d5d5 | 1799 | .next = &fair_sched_class, |
bb44e5d1 IM |
1800 | .enqueue_task = enqueue_task_rt, |
1801 | .dequeue_task = dequeue_task_rt, | |
1802 | .yield_task = yield_task_rt, | |
1803 | ||
1804 | .check_preempt_curr = check_preempt_curr_rt, | |
1805 | ||
1806 | .pick_next_task = pick_next_task_rt, | |
1807 | .put_prev_task = put_prev_task_rt, | |
1808 | ||
681f3e68 | 1809 | #ifdef CONFIG_SMP |
4ce72a2c LZ |
1810 | .select_task_rq = select_task_rq_rt, |
1811 | ||
73fe6aae | 1812 | .set_cpus_allowed = set_cpus_allowed_rt, |
1f11eb6a GH |
1813 | .rq_online = rq_online_rt, |
1814 | .rq_offline = rq_offline_rt, | |
9a897c5a SR |
1815 | .pre_schedule = pre_schedule_rt, |
1816 | .post_schedule = post_schedule_rt, | |
efbbd05a | 1817 | .task_woken = task_woken_rt, |
cb469845 | 1818 | .switched_from = switched_from_rt, |
681f3e68 | 1819 | #endif |
bb44e5d1 | 1820 | |
83b699ed | 1821 | .set_curr_task = set_curr_task_rt, |
bb44e5d1 | 1822 | .task_tick = task_tick_rt, |
cb469845 | 1823 | |
0d721cea PW |
1824 | .get_rr_interval = get_rr_interval_rt, |
1825 | ||
cb469845 SR |
1826 | .prio_changed = prio_changed_rt, |
1827 | .switched_to = switched_to_rt, | |
bb44e5d1 | 1828 | }; |
ada18de2 PZ |
1829 | |
1830 | #ifdef CONFIG_SCHED_DEBUG | |
1831 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
1832 | ||
1833 | static void print_rt_stats(struct seq_file *m, int cpu) | |
1834 | { | |
ec514c48 | 1835 | rt_rq_iter_t iter; |
ada18de2 PZ |
1836 | struct rt_rq *rt_rq; |
1837 | ||
1838 | rcu_read_lock(); | |
ec514c48 | 1839 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) |
ada18de2 PZ |
1840 | print_rt_rq(m, cpu, rt_rq); |
1841 | rcu_read_unlock(); | |
1842 | } | |
55e12e5e | 1843 | #endif /* CONFIG_SCHED_DEBUG */ |
0e3900e6 | 1844 |