Commit | Line | Data |
---|---|---|
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 | ||
1c09ab0d YZ |
188 | static inline struct task_group *next_task_group(struct task_group *tg) |
189 | { | |
190 | do { | |
191 | tg = list_entry_rcu(tg->list.next, | |
192 | typeof(struct task_group), list); | |
193 | } while (&tg->list != &task_groups && task_group_is_autogroup(tg)); | |
194 | ||
195 | if (&tg->list == &task_groups) | |
196 | tg = NULL; | |
197 | ||
198 | return tg; | |
199 | } | |
200 | ||
201 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
202 | for (iter = container_of(&task_groups, typeof(*iter), list); \ | |
203 | (iter = next_task_group(iter)) && \ | |
204 | (rt_rq = iter->rt_rq[cpu_of(rq)]);) | |
ec514c48 | 205 | |
3d4b47b4 PZ |
206 | static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) |
207 | { | |
208 | list_add_rcu(&rt_rq->leaf_rt_rq_list, | |
209 | &rq_of_rt_rq(rt_rq)->leaf_rt_rq_list); | |
210 | } | |
211 | ||
212 | static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq) | |
213 | { | |
214 | list_del_rcu(&rt_rq->leaf_rt_rq_list); | |
215 | } | |
216 | ||
6f505b16 | 217 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
80f40ee4 | 218 | list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) |
6f505b16 | 219 | |
6f505b16 PZ |
220 | #define for_each_sched_rt_entity(rt_se) \ |
221 | for (; rt_se; rt_se = rt_se->parent) | |
222 | ||
223 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
224 | { | |
225 | return rt_se->my_q; | |
226 | } | |
227 | ||
37dad3fc | 228 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head); |
6f505b16 PZ |
229 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se); |
230 | ||
9f0c1e56 | 231 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 232 | { |
f6121f4f | 233 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
74b7eb58 YZ |
234 | struct sched_rt_entity *rt_se; |
235 | ||
0c3b9168 BS |
236 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
237 | ||
238 | rt_se = rt_rq->tg->rt_se[cpu]; | |
6f505b16 | 239 | |
f6121f4f DF |
240 | if (rt_rq->rt_nr_running) { |
241 | if (rt_se && !on_rt_rq(rt_se)) | |
37dad3fc | 242 | enqueue_rt_entity(rt_se, false); |
e864c499 | 243 | if (rt_rq->highest_prio.curr < curr->prio) |
1020387f | 244 | resched_task(curr); |
6f505b16 PZ |
245 | } |
246 | } | |
247 | ||
9f0c1e56 | 248 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 249 | { |
74b7eb58 | 250 | struct sched_rt_entity *rt_se; |
0c3b9168 | 251 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
74b7eb58 | 252 | |
0c3b9168 | 253 | rt_se = rt_rq->tg->rt_se[cpu]; |
6f505b16 PZ |
254 | |
255 | if (rt_se && on_rt_rq(rt_se)) | |
256 | dequeue_rt_entity(rt_se); | |
257 | } | |
258 | ||
23b0fdfc PZ |
259 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
260 | { | |
261 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
262 | } | |
263 | ||
264 | static int rt_se_boosted(struct sched_rt_entity *rt_se) | |
265 | { | |
266 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
267 | struct task_struct *p; | |
268 | ||
269 | if (rt_rq) | |
270 | return !!rt_rq->rt_nr_boosted; | |
271 | ||
272 | p = rt_task_of(rt_se); | |
273 | return p->prio != p->normal_prio; | |
274 | } | |
275 | ||
d0b27fa7 | 276 | #ifdef CONFIG_SMP |
c6c4927b | 277 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 PZ |
278 | { |
279 | return cpu_rq(smp_processor_id())->rd->span; | |
280 | } | |
6f505b16 | 281 | #else |
c6c4927b | 282 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 283 | { |
c6c4927b | 284 | return cpu_online_mask; |
d0b27fa7 PZ |
285 | } |
286 | #endif | |
6f505b16 | 287 | |
d0b27fa7 PZ |
288 | static inline |
289 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 290 | { |
d0b27fa7 PZ |
291 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
292 | } | |
9f0c1e56 | 293 | |
ac086bc2 PZ |
294 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
295 | { | |
296 | return &rt_rq->tg->rt_bandwidth; | |
297 | } | |
298 | ||
55e12e5e | 299 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
300 | |
301 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
302 | { | |
ac086bc2 PZ |
303 | return rt_rq->rt_runtime; |
304 | } | |
305 | ||
306 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
307 | { | |
308 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
309 | } |
310 | ||
ec514c48 CX |
311 | typedef struct rt_rq *rt_rq_iter_t; |
312 | ||
313 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
314 | for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
315 | ||
3d4b47b4 PZ |
316 | static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) |
317 | { | |
318 | } | |
319 | ||
320 | static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq) | |
321 | { | |
322 | } | |
323 | ||
6f505b16 PZ |
324 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
325 | for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
326 | ||
6f505b16 PZ |
327 | #define for_each_sched_rt_entity(rt_se) \ |
328 | for (; rt_se; rt_se = NULL) | |
329 | ||
330 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
331 | { | |
332 | return NULL; | |
333 | } | |
334 | ||
9f0c1e56 | 335 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 336 | { |
f3ade837 JB |
337 | if (rt_rq->rt_nr_running) |
338 | resched_task(rq_of_rt_rq(rt_rq)->curr); | |
6f505b16 PZ |
339 | } |
340 | ||
9f0c1e56 | 341 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
342 | { |
343 | } | |
344 | ||
23b0fdfc PZ |
345 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
346 | { | |
347 | return rt_rq->rt_throttled; | |
348 | } | |
d0b27fa7 | 349 | |
c6c4927b | 350 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 351 | { |
c6c4927b | 352 | return cpu_online_mask; |
d0b27fa7 PZ |
353 | } |
354 | ||
355 | static inline | |
356 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
357 | { | |
358 | return &cpu_rq(cpu)->rt; | |
359 | } | |
360 | ||
ac086bc2 PZ |
361 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
362 | { | |
363 | return &def_rt_bandwidth; | |
364 | } | |
365 | ||
55e12e5e | 366 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 367 | |
ac086bc2 | 368 | #ifdef CONFIG_SMP |
78333cdd PZ |
369 | /* |
370 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
371 | */ | |
b79f3833 | 372 | static int do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
373 | { |
374 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
375 | struct root_domain *rd = cpu_rq(smp_processor_id())->rd; | |
376 | int i, weight, more = 0; | |
377 | u64 rt_period; | |
378 | ||
c6c4927b | 379 | weight = cpumask_weight(rd->span); |
ac086bc2 | 380 | |
0986b11b | 381 | raw_spin_lock(&rt_b->rt_runtime_lock); |
ac086bc2 | 382 | rt_period = ktime_to_ns(rt_b->rt_period); |
c6c4927b | 383 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
384 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
385 | s64 diff; | |
386 | ||
387 | if (iter == rt_rq) | |
388 | continue; | |
389 | ||
0986b11b | 390 | raw_spin_lock(&iter->rt_runtime_lock); |
78333cdd PZ |
391 | /* |
392 | * Either all rqs have inf runtime and there's nothing to steal | |
393 | * or __disable_runtime() below sets a specific rq to inf to | |
394 | * indicate its been disabled and disalow stealing. | |
395 | */ | |
7def2be1 PZ |
396 | if (iter->rt_runtime == RUNTIME_INF) |
397 | goto next; | |
398 | ||
78333cdd PZ |
399 | /* |
400 | * From runqueues with spare time, take 1/n part of their | |
401 | * spare time, but no more than our period. | |
402 | */ | |
ac086bc2 PZ |
403 | diff = iter->rt_runtime - iter->rt_time; |
404 | if (diff > 0) { | |
58838cf3 | 405 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
406 | if (rt_rq->rt_runtime + diff > rt_period) |
407 | diff = rt_period - rt_rq->rt_runtime; | |
408 | iter->rt_runtime -= diff; | |
409 | rt_rq->rt_runtime += diff; | |
410 | more = 1; | |
411 | if (rt_rq->rt_runtime == rt_period) { | |
0986b11b | 412 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 PZ |
413 | break; |
414 | } | |
415 | } | |
7def2be1 | 416 | next: |
0986b11b | 417 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 | 418 | } |
0986b11b | 419 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
ac086bc2 PZ |
420 | |
421 | return more; | |
422 | } | |
7def2be1 | 423 | |
78333cdd PZ |
424 | /* |
425 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
426 | */ | |
7def2be1 PZ |
427 | static void __disable_runtime(struct rq *rq) |
428 | { | |
429 | struct root_domain *rd = rq->rd; | |
ec514c48 | 430 | rt_rq_iter_t iter; |
7def2be1 PZ |
431 | struct rt_rq *rt_rq; |
432 | ||
433 | if (unlikely(!scheduler_running)) | |
434 | return; | |
435 | ||
ec514c48 | 436 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
437 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
438 | s64 want; | |
439 | int i; | |
440 | ||
0986b11b TG |
441 | raw_spin_lock(&rt_b->rt_runtime_lock); |
442 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
443 | /* |
444 | * Either we're all inf and nobody needs to borrow, or we're | |
445 | * already disabled and thus have nothing to do, or we have | |
446 | * exactly the right amount of runtime to take out. | |
447 | */ | |
7def2be1 PZ |
448 | if (rt_rq->rt_runtime == RUNTIME_INF || |
449 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
450 | goto balanced; | |
0986b11b | 451 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
7def2be1 | 452 | |
78333cdd PZ |
453 | /* |
454 | * Calculate the difference between what we started out with | |
455 | * and what we current have, that's the amount of runtime | |
456 | * we lend and now have to reclaim. | |
457 | */ | |
7def2be1 PZ |
458 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
459 | ||
78333cdd PZ |
460 | /* |
461 | * Greedy reclaim, take back as much as we can. | |
462 | */ | |
c6c4927b | 463 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
464 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
465 | s64 diff; | |
466 | ||
78333cdd PZ |
467 | /* |
468 | * Can't reclaim from ourselves or disabled runqueues. | |
469 | */ | |
f1679d08 | 470 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
471 | continue; |
472 | ||
0986b11b | 473 | raw_spin_lock(&iter->rt_runtime_lock); |
7def2be1 PZ |
474 | if (want > 0) { |
475 | diff = min_t(s64, iter->rt_runtime, want); | |
476 | iter->rt_runtime -= diff; | |
477 | want -= diff; | |
478 | } else { | |
479 | iter->rt_runtime -= want; | |
480 | want -= want; | |
481 | } | |
0986b11b | 482 | raw_spin_unlock(&iter->rt_runtime_lock); |
7def2be1 PZ |
483 | |
484 | if (!want) | |
485 | break; | |
486 | } | |
487 | ||
0986b11b | 488 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
78333cdd PZ |
489 | /* |
490 | * We cannot be left wanting - that would mean some runtime | |
491 | * leaked out of the system. | |
492 | */ | |
7def2be1 PZ |
493 | BUG_ON(want); |
494 | balanced: | |
78333cdd PZ |
495 | /* |
496 | * Disable all the borrow logic by pretending we have inf | |
497 | * runtime - in which case borrowing doesn't make sense. | |
498 | */ | |
7def2be1 | 499 | rt_rq->rt_runtime = RUNTIME_INF; |
0986b11b TG |
500 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
501 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
502 | } |
503 | } | |
504 | ||
505 | static void disable_runtime(struct rq *rq) | |
506 | { | |
507 | unsigned long flags; | |
508 | ||
05fa785c | 509 | raw_spin_lock_irqsave(&rq->lock, flags); |
7def2be1 | 510 | __disable_runtime(rq); |
05fa785c | 511 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
7def2be1 PZ |
512 | } |
513 | ||
514 | static void __enable_runtime(struct rq *rq) | |
515 | { | |
ec514c48 | 516 | rt_rq_iter_t iter; |
7def2be1 PZ |
517 | struct rt_rq *rt_rq; |
518 | ||
519 | if (unlikely(!scheduler_running)) | |
520 | return; | |
521 | ||
78333cdd PZ |
522 | /* |
523 | * Reset each runqueue's bandwidth settings | |
524 | */ | |
ec514c48 | 525 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
526 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
527 | ||
0986b11b TG |
528 | raw_spin_lock(&rt_b->rt_runtime_lock); |
529 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
7def2be1 PZ |
530 | rt_rq->rt_runtime = rt_b->rt_runtime; |
531 | rt_rq->rt_time = 0; | |
baf25731 | 532 | rt_rq->rt_throttled = 0; |
0986b11b TG |
533 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
534 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
535 | } |
536 | } | |
537 | ||
538 | static void enable_runtime(struct rq *rq) | |
539 | { | |
540 | unsigned long flags; | |
541 | ||
05fa785c | 542 | raw_spin_lock_irqsave(&rq->lock, flags); |
7def2be1 | 543 | __enable_runtime(rq); |
05fa785c | 544 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
7def2be1 PZ |
545 | } |
546 | ||
eff6549b PZ |
547 | static int balance_runtime(struct rt_rq *rt_rq) |
548 | { | |
549 | int more = 0; | |
550 | ||
551 | if (rt_rq->rt_time > rt_rq->rt_runtime) { | |
0986b11b | 552 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
eff6549b | 553 | more = do_balance_runtime(rt_rq); |
0986b11b | 554 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
555 | } |
556 | ||
557 | return more; | |
558 | } | |
55e12e5e | 559 | #else /* !CONFIG_SMP */ |
eff6549b PZ |
560 | static inline int balance_runtime(struct rt_rq *rt_rq) |
561 | { | |
562 | return 0; | |
563 | } | |
55e12e5e | 564 | #endif /* CONFIG_SMP */ |
ac086bc2 | 565 | |
eff6549b PZ |
566 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
567 | { | |
568 | int i, idle = 1; | |
c6c4927b | 569 | const struct cpumask *span; |
eff6549b | 570 | |
0b148fa0 | 571 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
eff6549b PZ |
572 | return 1; |
573 | ||
574 | span = sched_rt_period_mask(); | |
c6c4927b | 575 | for_each_cpu(i, span) { |
eff6549b PZ |
576 | int enqueue = 0; |
577 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
578 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
579 | ||
05fa785c | 580 | raw_spin_lock(&rq->lock); |
eff6549b PZ |
581 | if (rt_rq->rt_time) { |
582 | u64 runtime; | |
583 | ||
0986b11b | 584 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
585 | if (rt_rq->rt_throttled) |
586 | balance_runtime(rt_rq); | |
587 | runtime = rt_rq->rt_runtime; | |
588 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
589 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
590 | rt_rq->rt_throttled = 0; | |
591 | enqueue = 1; | |
61eadef6 MG |
592 | |
593 | /* | |
594 | * Force a clock update if the CPU was idle, | |
595 | * lest wakeup -> unthrottle time accumulate. | |
596 | */ | |
597 | if (rt_rq->rt_nr_running && rq->curr == rq->idle) | |
598 | rq->skip_clock_update = -1; | |
eff6549b PZ |
599 | } |
600 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
601 | idle = 0; | |
0986b11b | 602 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
0c3b9168 | 603 | } else if (rt_rq->rt_nr_running) { |
6c3df255 | 604 | idle = 0; |
0c3b9168 BS |
605 | if (!rt_rq_throttled(rt_rq)) |
606 | enqueue = 1; | |
607 | } | |
eff6549b PZ |
608 | |
609 | if (enqueue) | |
610 | sched_rt_rq_enqueue(rt_rq); | |
05fa785c | 611 | raw_spin_unlock(&rq->lock); |
eff6549b PZ |
612 | } |
613 | ||
614 | return idle; | |
615 | } | |
ac086bc2 | 616 | |
6f505b16 PZ |
617 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
618 | { | |
052f1dc7 | 619 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
620 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
621 | ||
622 | if (rt_rq) | |
e864c499 | 623 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
624 | #endif |
625 | ||
626 | return rt_task_of(rt_se)->prio; | |
627 | } | |
628 | ||
9f0c1e56 | 629 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 630 | { |
9f0c1e56 | 631 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 632 | |
fa85ae24 | 633 | if (rt_rq->rt_throttled) |
23b0fdfc | 634 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 635 | |
ac086bc2 PZ |
636 | if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) |
637 | return 0; | |
638 | ||
b79f3833 PZ |
639 | balance_runtime(rt_rq); |
640 | runtime = sched_rt_runtime(rt_rq); | |
641 | if (runtime == RUNTIME_INF) | |
642 | return 0; | |
ac086bc2 | 643 | |
9f0c1e56 | 644 | if (rt_rq->rt_time > runtime) { |
6f505b16 | 645 | rt_rq->rt_throttled = 1; |
23b0fdfc | 646 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 647 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
648 | return 1; |
649 | } | |
fa85ae24 PZ |
650 | } |
651 | ||
652 | return 0; | |
653 | } | |
654 | ||
bb44e5d1 IM |
655 | /* |
656 | * Update the current task's runtime statistics. Skip current tasks that | |
657 | * are not in our scheduling class. | |
658 | */ | |
a9957449 | 659 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
660 | { |
661 | struct task_struct *curr = rq->curr; | |
6f505b16 PZ |
662 | struct sched_rt_entity *rt_se = &curr->rt; |
663 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
bb44e5d1 IM |
664 | u64 delta_exec; |
665 | ||
06c3bc65 | 666 | if (curr->sched_class != &rt_sched_class) |
bb44e5d1 IM |
667 | return; |
668 | ||
305e6835 | 669 | delta_exec = rq->clock_task - curr->se.exec_start; |
bb44e5d1 IM |
670 | if (unlikely((s64)delta_exec < 0)) |
671 | delta_exec = 0; | |
6cfb0d5d | 672 | |
41acab88 | 673 | schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec)); |
bb44e5d1 IM |
674 | |
675 | curr->se.sum_exec_runtime += delta_exec; | |
f06febc9 FM |
676 | account_group_exec_runtime(curr, delta_exec); |
677 | ||
305e6835 | 678 | curr->se.exec_start = rq->clock_task; |
d842de87 | 679 | cpuacct_charge(curr, delta_exec); |
fa85ae24 | 680 | |
e9e9250b PZ |
681 | sched_rt_avg_update(rq, delta_exec); |
682 | ||
0b148fa0 PZ |
683 | if (!rt_bandwidth_enabled()) |
684 | return; | |
685 | ||
354d60c2 DG |
686 | for_each_sched_rt_entity(rt_se) { |
687 | rt_rq = rt_rq_of_se(rt_se); | |
688 | ||
cc2991cf | 689 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
0986b11b | 690 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf PZ |
691 | rt_rq->rt_time += delta_exec; |
692 | if (sched_rt_runtime_exceeded(rt_rq)) | |
693 | resched_task(curr); | |
0986b11b | 694 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
cc2991cf | 695 | } |
354d60c2 | 696 | } |
bb44e5d1 IM |
697 | } |
698 | ||
398a153b | 699 | #if defined CONFIG_SMP |
e864c499 GH |
700 | |
701 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu); | |
702 | ||
703 | static inline int next_prio(struct rq *rq) | |
63489e45 | 704 | { |
e864c499 GH |
705 | struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu); |
706 | ||
707 | if (next && rt_prio(next->prio)) | |
708 | return next->prio; | |
709 | else | |
710 | return MAX_RT_PRIO; | |
711 | } | |
e864c499 | 712 | |
398a153b GH |
713 | static void |
714 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 715 | { |
4d984277 | 716 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 717 | |
398a153b | 718 | if (prio < prev_prio) { |
4d984277 | 719 | |
e864c499 GH |
720 | /* |
721 | * If the new task is higher in priority than anything on the | |
398a153b GH |
722 | * run-queue, we know that the previous high becomes our |
723 | * next-highest. | |
e864c499 | 724 | */ |
398a153b | 725 | rt_rq->highest_prio.next = prev_prio; |
1f11eb6a GH |
726 | |
727 | if (rq->online) | |
4d984277 | 728 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); |
1100ac91 | 729 | |
e864c499 GH |
730 | } else if (prio == rt_rq->highest_prio.curr) |
731 | /* | |
732 | * If the next task is equal in priority to the highest on | |
733 | * the run-queue, then we implicitly know that the next highest | |
734 | * task cannot be any lower than current | |
735 | */ | |
736 | rt_rq->highest_prio.next = prio; | |
737 | else if (prio < rt_rq->highest_prio.next) | |
738 | /* | |
739 | * Otherwise, we need to recompute next-highest | |
740 | */ | |
741 | rt_rq->highest_prio.next = next_prio(rq); | |
398a153b | 742 | } |
73fe6aae | 743 | |
398a153b GH |
744 | static void |
745 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
746 | { | |
747 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 748 | |
398a153b GH |
749 | if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next)) |
750 | rt_rq->highest_prio.next = next_prio(rq); | |
751 | ||
752 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) | |
753 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
754 | } |
755 | ||
398a153b GH |
756 | #else /* CONFIG_SMP */ |
757 | ||
6f505b16 | 758 | static inline |
398a153b GH |
759 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
760 | static inline | |
761 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
762 | ||
763 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 764 | |
052f1dc7 | 765 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
766 | static void |
767 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
768 | { | |
769 | int prev_prio = rt_rq->highest_prio.curr; | |
770 | ||
771 | if (prio < prev_prio) | |
772 | rt_rq->highest_prio.curr = prio; | |
773 | ||
774 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
775 | } | |
776 | ||
777 | static void | |
778 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
779 | { | |
780 | int prev_prio = rt_rq->highest_prio.curr; | |
781 | ||
6f505b16 | 782 | if (rt_rq->rt_nr_running) { |
764a9d6f | 783 | |
398a153b | 784 | WARN_ON(prio < prev_prio); |
764a9d6f | 785 | |
e864c499 | 786 | /* |
398a153b GH |
787 | * This may have been our highest task, and therefore |
788 | * we may have some recomputation to do | |
e864c499 | 789 | */ |
398a153b | 790 | if (prio == prev_prio) { |
e864c499 GH |
791 | struct rt_prio_array *array = &rt_rq->active; |
792 | ||
793 | rt_rq->highest_prio.curr = | |
764a9d6f | 794 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
795 | } |
796 | ||
764a9d6f | 797 | } else |
e864c499 | 798 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
73fe6aae | 799 | |
398a153b GH |
800 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
801 | } | |
1f11eb6a | 802 | |
398a153b GH |
803 | #else |
804 | ||
805 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
806 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
807 | ||
808 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 809 | |
052f1dc7 | 810 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
811 | |
812 | static void | |
813 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
814 | { | |
815 | if (rt_se_boosted(rt_se)) | |
816 | rt_rq->rt_nr_boosted++; | |
817 | ||
818 | if (rt_rq->tg) | |
819 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
820 | } | |
821 | ||
822 | static void | |
823 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
824 | { | |
23b0fdfc PZ |
825 | if (rt_se_boosted(rt_se)) |
826 | rt_rq->rt_nr_boosted--; | |
827 | ||
828 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
398a153b GH |
829 | } |
830 | ||
831 | #else /* CONFIG_RT_GROUP_SCHED */ | |
832 | ||
833 | static void | |
834 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
835 | { | |
836 | start_rt_bandwidth(&def_rt_bandwidth); | |
837 | } | |
838 | ||
839 | static inline | |
840 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
841 | ||
842 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
843 | ||
844 | static inline | |
845 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
846 | { | |
847 | int prio = rt_se_prio(rt_se); | |
848 | ||
849 | WARN_ON(!rt_prio(prio)); | |
850 | rt_rq->rt_nr_running++; | |
851 | ||
852 | inc_rt_prio(rt_rq, prio); | |
853 | inc_rt_migration(rt_se, rt_rq); | |
854 | inc_rt_group(rt_se, rt_rq); | |
855 | } | |
856 | ||
857 | static inline | |
858 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
859 | { | |
860 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
861 | WARN_ON(!rt_rq->rt_nr_running); | |
862 | rt_rq->rt_nr_running--; | |
863 | ||
864 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
865 | dec_rt_migration(rt_se, rt_rq); | |
866 | dec_rt_group(rt_se, rt_rq); | |
63489e45 SR |
867 | } |
868 | ||
37dad3fc | 869 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head) |
bb44e5d1 | 870 | { |
6f505b16 PZ |
871 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
872 | struct rt_prio_array *array = &rt_rq->active; | |
873 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 874 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 875 | |
ad2a3f13 PZ |
876 | /* |
877 | * Don't enqueue the group if its throttled, or when empty. | |
878 | * The latter is a consequence of the former when a child group | |
879 | * get throttled and the current group doesn't have any other | |
880 | * active members. | |
881 | */ | |
882 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) | |
6f505b16 | 883 | return; |
63489e45 | 884 | |
3d4b47b4 PZ |
885 | if (!rt_rq->rt_nr_running) |
886 | list_add_leaf_rt_rq(rt_rq); | |
887 | ||
37dad3fc TG |
888 | if (head) |
889 | list_add(&rt_se->run_list, queue); | |
890 | else | |
891 | list_add_tail(&rt_se->run_list, queue); | |
6f505b16 | 892 | __set_bit(rt_se_prio(rt_se), array->bitmap); |
78f2c7db | 893 | |
6f505b16 PZ |
894 | inc_rt_tasks(rt_se, rt_rq); |
895 | } | |
896 | ||
ad2a3f13 | 897 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) |
6f505b16 PZ |
898 | { |
899 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
900 | struct rt_prio_array *array = &rt_rq->active; | |
901 | ||
902 | list_del_init(&rt_se->run_list); | |
903 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
904 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
905 | ||
906 | dec_rt_tasks(rt_se, rt_rq); | |
3d4b47b4 PZ |
907 | if (!rt_rq->rt_nr_running) |
908 | list_del_leaf_rt_rq(rt_rq); | |
6f505b16 PZ |
909 | } |
910 | ||
911 | /* | |
912 | * Because the prio of an upper entry depends on the lower | |
913 | * entries, we must remove entries top - down. | |
6f505b16 | 914 | */ |
ad2a3f13 | 915 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se) |
6f505b16 | 916 | { |
ad2a3f13 | 917 | struct sched_rt_entity *back = NULL; |
6f505b16 | 918 | |
58d6c2d7 PZ |
919 | for_each_sched_rt_entity(rt_se) { |
920 | rt_se->back = back; | |
921 | back = rt_se; | |
922 | } | |
923 | ||
924 | for (rt_se = back; rt_se; rt_se = rt_se->back) { | |
925 | if (on_rt_rq(rt_se)) | |
ad2a3f13 PZ |
926 | __dequeue_rt_entity(rt_se); |
927 | } | |
928 | } | |
929 | ||
37dad3fc | 930 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head) |
ad2a3f13 PZ |
931 | { |
932 | dequeue_rt_stack(rt_se); | |
933 | for_each_sched_rt_entity(rt_se) | |
37dad3fc | 934 | __enqueue_rt_entity(rt_se, head); |
ad2a3f13 PZ |
935 | } |
936 | ||
937 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se) | |
938 | { | |
939 | dequeue_rt_stack(rt_se); | |
940 | ||
941 | for_each_sched_rt_entity(rt_se) { | |
942 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
943 | ||
944 | if (rt_rq && rt_rq->rt_nr_running) | |
37dad3fc | 945 | __enqueue_rt_entity(rt_se, false); |
58d6c2d7 | 946 | } |
bb44e5d1 IM |
947 | } |
948 | ||
949 | /* | |
950 | * Adding/removing a task to/from a priority array: | |
951 | */ | |
ea87bb78 | 952 | static void |
371fd7e7 | 953 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
6f505b16 PZ |
954 | { |
955 | struct sched_rt_entity *rt_se = &p->rt; | |
956 | ||
371fd7e7 | 957 | if (flags & ENQUEUE_WAKEUP) |
6f505b16 PZ |
958 | rt_se->timeout = 0; |
959 | ||
371fd7e7 | 960 | enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD); |
c09595f6 | 961 | |
917b627d GH |
962 | if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) |
963 | enqueue_pushable_task(rq, p); | |
6f505b16 PZ |
964 | } |
965 | ||
371fd7e7 | 966 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 967 | { |
6f505b16 | 968 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 969 | |
f1e14ef6 | 970 | update_curr_rt(rq); |
ad2a3f13 | 971 | dequeue_rt_entity(rt_se); |
c09595f6 | 972 | |
917b627d | 973 | dequeue_pushable_task(rq, p); |
bb44e5d1 IM |
974 | } |
975 | ||
976 | /* | |
977 | * Put task to the end of the run list without the overhead of dequeue | |
978 | * followed by enqueue. | |
979 | */ | |
7ebefa8c DA |
980 | static void |
981 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 982 | { |
1cdad715 | 983 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
984 | struct rt_prio_array *array = &rt_rq->active; |
985 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
986 | ||
987 | if (head) | |
988 | list_move(&rt_se->run_list, queue); | |
989 | else | |
990 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 991 | } |
6f505b16 PZ |
992 | } |
993 | ||
7ebefa8c | 994 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 995 | { |
6f505b16 PZ |
996 | struct sched_rt_entity *rt_se = &p->rt; |
997 | struct rt_rq *rt_rq; | |
bb44e5d1 | 998 | |
6f505b16 PZ |
999 | for_each_sched_rt_entity(rt_se) { |
1000 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 1001 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 1002 | } |
bb44e5d1 IM |
1003 | } |
1004 | ||
6f505b16 | 1005 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 1006 | { |
7ebefa8c | 1007 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
1008 | } |
1009 | ||
e7693a36 | 1010 | #ifdef CONFIG_SMP |
318e0893 GH |
1011 | static int find_lowest_rq(struct task_struct *task); |
1012 | ||
0017d735 | 1013 | static int |
7608dec2 | 1014 | select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) |
e7693a36 | 1015 | { |
7608dec2 PZ |
1016 | struct task_struct *curr; |
1017 | struct rq *rq; | |
1018 | int cpu; | |
1019 | ||
0763a660 | 1020 | if (sd_flag != SD_BALANCE_WAKE) |
5f3edc1b PZ |
1021 | return smp_processor_id(); |
1022 | ||
7608dec2 PZ |
1023 | cpu = task_cpu(p); |
1024 | rq = cpu_rq(cpu); | |
1025 | ||
1026 | rcu_read_lock(); | |
1027 | curr = ACCESS_ONCE(rq->curr); /* unlocked access */ | |
1028 | ||
318e0893 | 1029 | /* |
7608dec2 | 1030 | * If the current task on @p's runqueue is an RT task, then |
e1f47d89 SR |
1031 | * try to see if we can wake this RT task up on another |
1032 | * runqueue. Otherwise simply start this RT task | |
1033 | * on its current runqueue. | |
1034 | * | |
43fa5460 SR |
1035 | * We want to avoid overloading runqueues. If the woken |
1036 | * task is a higher priority, then it will stay on this CPU | |
1037 | * and the lower prio task should be moved to another CPU. | |
1038 | * Even though this will probably make the lower prio task | |
1039 | * lose its cache, we do not want to bounce a higher task | |
1040 | * around just because it gave up its CPU, perhaps for a | |
1041 | * lock? | |
1042 | * | |
1043 | * For equal prio tasks, we just let the scheduler sort it out. | |
7608dec2 PZ |
1044 | * |
1045 | * Otherwise, just let it ride on the affined RQ and the | |
1046 | * post-schedule router will push the preempted task away | |
1047 | * | |
1048 | * This test is optimistic, if we get it wrong the load-balancer | |
1049 | * will have to sort it out. | |
318e0893 | 1050 | */ |
7608dec2 PZ |
1051 | if (curr && unlikely(rt_task(curr)) && |
1052 | (curr->rt.nr_cpus_allowed < 2 || | |
1053 | curr->prio < p->prio) && | |
6f505b16 | 1054 | (p->rt.nr_cpus_allowed > 1)) { |
7608dec2 | 1055 | int target = find_lowest_rq(p); |
318e0893 | 1056 | |
7608dec2 PZ |
1057 | if (target != -1) |
1058 | cpu = target; | |
318e0893 | 1059 | } |
7608dec2 | 1060 | rcu_read_unlock(); |
318e0893 | 1061 | |
7608dec2 | 1062 | return cpu; |
e7693a36 | 1063 | } |
7ebefa8c DA |
1064 | |
1065 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1066 | { | |
7ebefa8c DA |
1067 | if (rq->curr->rt.nr_cpus_allowed == 1) |
1068 | return; | |
1069 | ||
24600ce8 | 1070 | if (p->rt.nr_cpus_allowed != 1 |
13b8bd0a RR |
1071 | && cpupri_find(&rq->rd->cpupri, p, NULL)) |
1072 | return; | |
24600ce8 | 1073 | |
13b8bd0a RR |
1074 | if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) |
1075 | return; | |
7ebefa8c DA |
1076 | |
1077 | /* | |
1078 | * There appears to be other cpus that can accept | |
1079 | * current and none to run 'p', so lets reschedule | |
1080 | * to try and push current away: | |
1081 | */ | |
1082 | requeue_task_rt(rq, p, 1); | |
1083 | resched_task(rq->curr); | |
1084 | } | |
1085 | ||
e7693a36 GH |
1086 | #endif /* CONFIG_SMP */ |
1087 | ||
bb44e5d1 IM |
1088 | /* |
1089 | * Preempt the current task with a newly woken task if needed: | |
1090 | */ | |
7d478721 | 1091 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1092 | { |
45c01e82 | 1093 | if (p->prio < rq->curr->prio) { |
bb44e5d1 | 1094 | resched_task(rq->curr); |
45c01e82 GH |
1095 | return; |
1096 | } | |
1097 | ||
1098 | #ifdef CONFIG_SMP | |
1099 | /* | |
1100 | * If: | |
1101 | * | |
1102 | * - the newly woken task is of equal priority to the current task | |
1103 | * - the newly woken task is non-migratable while current is migratable | |
1104 | * - current will be preempted on the next reschedule | |
1105 | * | |
1106 | * we should check to see if current can readily move to a different | |
1107 | * cpu. If so, we will reschedule to allow the push logic to try | |
1108 | * to move current somewhere else, making room for our non-migratable | |
1109 | * task. | |
1110 | */ | |
8dd0de8b | 1111 | if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) |
7ebefa8c | 1112 | check_preempt_equal_prio(rq, p); |
45c01e82 | 1113 | #endif |
bb44e5d1 IM |
1114 | } |
1115 | ||
6f505b16 PZ |
1116 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
1117 | struct rt_rq *rt_rq) | |
bb44e5d1 | 1118 | { |
6f505b16 PZ |
1119 | struct rt_prio_array *array = &rt_rq->active; |
1120 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1121 | struct list_head *queue; |
1122 | int idx; | |
1123 | ||
1124 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1125 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1126 | |
1127 | queue = array->queue + idx; | |
6f505b16 | 1128 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1129 | |
6f505b16 PZ |
1130 | return next; |
1131 | } | |
bb44e5d1 | 1132 | |
917b627d | 1133 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1134 | { |
1135 | struct sched_rt_entity *rt_se; | |
1136 | struct task_struct *p; | |
1137 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1138 | |
6f505b16 PZ |
1139 | rt_rq = &rq->rt; |
1140 | ||
8e54a2c0 | 1141 | if (!rt_rq->rt_nr_running) |
6f505b16 PZ |
1142 | return NULL; |
1143 | ||
23b0fdfc | 1144 | if (rt_rq_throttled(rt_rq)) |
6f505b16 PZ |
1145 | return NULL; |
1146 | ||
1147 | do { | |
1148 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
326587b8 | 1149 | BUG_ON(!rt_se); |
6f505b16 PZ |
1150 | rt_rq = group_rt_rq(rt_se); |
1151 | } while (rt_rq); | |
1152 | ||
1153 | p = rt_task_of(rt_se); | |
305e6835 | 1154 | p->se.exec_start = rq->clock_task; |
917b627d GH |
1155 | |
1156 | return p; | |
1157 | } | |
1158 | ||
1159 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
1160 | { | |
1161 | struct task_struct *p = _pick_next_task_rt(rq); | |
1162 | ||
1163 | /* The running task is never eligible for pushing */ | |
1164 | if (p) | |
1165 | dequeue_pushable_task(rq, p); | |
1166 | ||
bcf08df3 | 1167 | #ifdef CONFIG_SMP |
3f029d3c GH |
1168 | /* |
1169 | * We detect this state here so that we can avoid taking the RQ | |
1170 | * lock again later if there is no need to push | |
1171 | */ | |
1172 | rq->post_schedule = has_pushable_tasks(rq); | |
bcf08df3 | 1173 | #endif |
3f029d3c | 1174 | |
6f505b16 | 1175 | return p; |
bb44e5d1 IM |
1176 | } |
1177 | ||
31ee529c | 1178 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1179 | { |
f1e14ef6 | 1180 | update_curr_rt(rq); |
bb44e5d1 | 1181 | p->se.exec_start = 0; |
917b627d GH |
1182 | |
1183 | /* | |
1184 | * The previous task needs to be made eligible for pushing | |
1185 | * if it is still active | |
1186 | */ | |
fd2f4419 | 1187 | if (on_rt_rq(&p->rt) && p->rt.nr_cpus_allowed > 1) |
917b627d | 1188 | enqueue_pushable_task(rq, p); |
bb44e5d1 IM |
1189 | } |
1190 | ||
681f3e68 | 1191 | #ifdef CONFIG_SMP |
6f505b16 | 1192 | |
e8fa1362 SR |
1193 | /* Only try algorithms three times */ |
1194 | #define RT_MAX_TRIES 3 | |
1195 | ||
e8fa1362 SR |
1196 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); |
1197 | ||
f65eda4f SR |
1198 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1199 | { | |
1200 | if (!task_running(rq, p) && | |
96f874e2 | 1201 | (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) && |
6f505b16 | 1202 | (p->rt.nr_cpus_allowed > 1)) |
f65eda4f SR |
1203 | return 1; |
1204 | return 0; | |
1205 | } | |
1206 | ||
e8fa1362 | 1207 | /* Return the second highest RT task, NULL otherwise */ |
79064fbf | 1208 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) |
e8fa1362 | 1209 | { |
6f505b16 PZ |
1210 | struct task_struct *next = NULL; |
1211 | struct sched_rt_entity *rt_se; | |
1212 | struct rt_prio_array *array; | |
1213 | struct rt_rq *rt_rq; | |
e8fa1362 SR |
1214 | int idx; |
1215 | ||
6f505b16 PZ |
1216 | for_each_leaf_rt_rq(rt_rq, rq) { |
1217 | array = &rt_rq->active; | |
1218 | idx = sched_find_first_bit(array->bitmap); | |
49246274 | 1219 | next_idx: |
6f505b16 PZ |
1220 | if (idx >= MAX_RT_PRIO) |
1221 | continue; | |
1222 | if (next && next->prio < idx) | |
1223 | continue; | |
1224 | list_for_each_entry(rt_se, array->queue + idx, run_list) { | |
3d07467b PZ |
1225 | struct task_struct *p; |
1226 | ||
1227 | if (!rt_entity_is_task(rt_se)) | |
1228 | continue; | |
1229 | ||
1230 | p = rt_task_of(rt_se); | |
6f505b16 PZ |
1231 | if (pick_rt_task(rq, p, cpu)) { |
1232 | next = p; | |
1233 | break; | |
1234 | } | |
1235 | } | |
1236 | if (!next) { | |
1237 | idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); | |
1238 | goto next_idx; | |
1239 | } | |
f65eda4f SR |
1240 | } |
1241 | ||
e8fa1362 SR |
1242 | return next; |
1243 | } | |
1244 | ||
0e3900e6 | 1245 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1246 | |
6e1254d2 GH |
1247 | static int find_lowest_rq(struct task_struct *task) |
1248 | { | |
1249 | struct sched_domain *sd; | |
96f874e2 | 1250 | struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); |
6e1254d2 GH |
1251 | int this_cpu = smp_processor_id(); |
1252 | int cpu = task_cpu(task); | |
06f90dbd | 1253 | |
0da938c4 SR |
1254 | /* Make sure the mask is initialized first */ |
1255 | if (unlikely(!lowest_mask)) | |
1256 | return -1; | |
1257 | ||
6e0534f2 GH |
1258 | if (task->rt.nr_cpus_allowed == 1) |
1259 | return -1; /* No other targets possible */ | |
6e1254d2 | 1260 | |
6e0534f2 GH |
1261 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
1262 | return -1; /* No targets found */ | |
6e1254d2 GH |
1263 | |
1264 | /* | |
1265 | * At this point we have built a mask of cpus representing the | |
1266 | * lowest priority tasks in the system. Now we want to elect | |
1267 | * the best one based on our affinity and topology. | |
1268 | * | |
1269 | * We prioritize the last cpu that the task executed on since | |
1270 | * it is most likely cache-hot in that location. | |
1271 | */ | |
96f874e2 | 1272 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1273 | return cpu; |
1274 | ||
1275 | /* | |
1276 | * Otherwise, we consult the sched_domains span maps to figure | |
1277 | * out which cpu is logically closest to our hot cache data. | |
1278 | */ | |
e2c88063 RR |
1279 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) |
1280 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
6e1254d2 | 1281 | |
cd4ae6ad | 1282 | rcu_read_lock(); |
e2c88063 RR |
1283 | for_each_domain(cpu, sd) { |
1284 | if (sd->flags & SD_WAKE_AFFINE) { | |
1285 | int best_cpu; | |
6e1254d2 | 1286 | |
e2c88063 RR |
1287 | /* |
1288 | * "this_cpu" is cheaper to preempt than a | |
1289 | * remote processor. | |
1290 | */ | |
1291 | if (this_cpu != -1 && | |
cd4ae6ad XF |
1292 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { |
1293 | rcu_read_unlock(); | |
e2c88063 | 1294 | return this_cpu; |
cd4ae6ad | 1295 | } |
e2c88063 RR |
1296 | |
1297 | best_cpu = cpumask_first_and(lowest_mask, | |
1298 | sched_domain_span(sd)); | |
cd4ae6ad XF |
1299 | if (best_cpu < nr_cpu_ids) { |
1300 | rcu_read_unlock(); | |
e2c88063 | 1301 | return best_cpu; |
cd4ae6ad | 1302 | } |
6e1254d2 GH |
1303 | } |
1304 | } | |
cd4ae6ad | 1305 | rcu_read_unlock(); |
6e1254d2 GH |
1306 | |
1307 | /* | |
1308 | * And finally, if there were no matches within the domains | |
1309 | * just give the caller *something* to work with from the compatible | |
1310 | * locations. | |
1311 | */ | |
e2c88063 RR |
1312 | if (this_cpu != -1) |
1313 | return this_cpu; | |
1314 | ||
1315 | cpu = cpumask_any(lowest_mask); | |
1316 | if (cpu < nr_cpu_ids) | |
1317 | return cpu; | |
1318 | return -1; | |
07b4032c GH |
1319 | } |
1320 | ||
1321 | /* Will lock the rq it finds */ | |
4df64c0b | 1322 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1323 | { |
1324 | struct rq *lowest_rq = NULL; | |
07b4032c | 1325 | int tries; |
4df64c0b | 1326 | int cpu; |
e8fa1362 | 1327 | |
07b4032c GH |
1328 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1329 | cpu = find_lowest_rq(task); | |
1330 | ||
2de0b463 | 1331 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1332 | break; |
1333 | ||
07b4032c GH |
1334 | lowest_rq = cpu_rq(cpu); |
1335 | ||
e8fa1362 | 1336 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1337 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1338 | /* |
1339 | * We had to unlock the run queue. In | |
1340 | * the mean time, task could have | |
1341 | * migrated already or had its affinity changed. | |
1342 | * Also make sure that it wasn't scheduled on its rq. | |
1343 | */ | |
07b4032c | 1344 | if (unlikely(task_rq(task) != rq || |
96f874e2 RR |
1345 | !cpumask_test_cpu(lowest_rq->cpu, |
1346 | &task->cpus_allowed) || | |
07b4032c | 1347 | task_running(rq, task) || |
fd2f4419 | 1348 | !task->on_rq)) { |
4df64c0b | 1349 | |
05fa785c | 1350 | raw_spin_unlock(&lowest_rq->lock); |
e8fa1362 SR |
1351 | lowest_rq = NULL; |
1352 | break; | |
1353 | } | |
1354 | } | |
1355 | ||
1356 | /* If this rq is still suitable use it. */ | |
e864c499 | 1357 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1358 | break; |
1359 | ||
1360 | /* try again */ | |
1b12bbc7 | 1361 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1362 | lowest_rq = NULL; |
1363 | } | |
1364 | ||
1365 | return lowest_rq; | |
1366 | } | |
1367 | ||
917b627d GH |
1368 | static struct task_struct *pick_next_pushable_task(struct rq *rq) |
1369 | { | |
1370 | struct task_struct *p; | |
1371 | ||
1372 | if (!has_pushable_tasks(rq)) | |
1373 | return NULL; | |
1374 | ||
1375 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1376 | struct task_struct, pushable_tasks); | |
1377 | ||
1378 | BUG_ON(rq->cpu != task_cpu(p)); | |
1379 | BUG_ON(task_current(rq, p)); | |
1380 | BUG_ON(p->rt.nr_cpus_allowed <= 1); | |
1381 | ||
fd2f4419 | 1382 | BUG_ON(!p->on_rq); |
917b627d GH |
1383 | BUG_ON(!rt_task(p)); |
1384 | ||
1385 | return p; | |
1386 | } | |
1387 | ||
e8fa1362 SR |
1388 | /* |
1389 | * If the current CPU has more than one RT task, see if the non | |
1390 | * running task can migrate over to a CPU that is running a task | |
1391 | * of lesser priority. | |
1392 | */ | |
697f0a48 | 1393 | static int push_rt_task(struct rq *rq) |
e8fa1362 SR |
1394 | { |
1395 | struct task_struct *next_task; | |
1396 | struct rq *lowest_rq; | |
e8fa1362 | 1397 | |
a22d7fc1 GH |
1398 | if (!rq->rt.overloaded) |
1399 | return 0; | |
1400 | ||
917b627d | 1401 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
1402 | if (!next_task) |
1403 | return 0; | |
1404 | ||
49246274 | 1405 | retry: |
697f0a48 | 1406 | if (unlikely(next_task == rq->curr)) { |
f65eda4f | 1407 | WARN_ON(1); |
e8fa1362 | 1408 | return 0; |
f65eda4f | 1409 | } |
e8fa1362 SR |
1410 | |
1411 | /* | |
1412 | * It's possible that the next_task slipped in of | |
1413 | * higher priority than current. If that's the case | |
1414 | * just reschedule current. | |
1415 | */ | |
697f0a48 GH |
1416 | if (unlikely(next_task->prio < rq->curr->prio)) { |
1417 | resched_task(rq->curr); | |
e8fa1362 SR |
1418 | return 0; |
1419 | } | |
1420 | ||
697f0a48 | 1421 | /* We might release rq lock */ |
e8fa1362 SR |
1422 | get_task_struct(next_task); |
1423 | ||
1424 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 1425 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
1426 | if (!lowest_rq) { |
1427 | struct task_struct *task; | |
1428 | /* | |
697f0a48 | 1429 | * find lock_lowest_rq releases rq->lock |
1563513d GH |
1430 | * so it is possible that next_task has migrated. |
1431 | * | |
1432 | * We need to make sure that the task is still on the same | |
1433 | * run-queue and is also still the next task eligible for | |
1434 | * pushing. | |
e8fa1362 | 1435 | */ |
917b627d | 1436 | task = pick_next_pushable_task(rq); |
1563513d GH |
1437 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
1438 | /* | |
25985edc | 1439 | * If we get here, the task hasn't moved at all, but |
1563513d GH |
1440 | * it has failed to push. We will not try again, |
1441 | * since the other cpus will pull from us when they | |
1442 | * are ready. | |
1443 | */ | |
1444 | dequeue_pushable_task(rq, next_task); | |
1445 | goto out; | |
e8fa1362 | 1446 | } |
917b627d | 1447 | |
1563513d GH |
1448 | if (!task) |
1449 | /* No more tasks, just exit */ | |
1450 | goto out; | |
1451 | ||
917b627d | 1452 | /* |
1563513d | 1453 | * Something has shifted, try again. |
917b627d | 1454 | */ |
1563513d GH |
1455 | put_task_struct(next_task); |
1456 | next_task = task; | |
1457 | goto retry; | |
e8fa1362 SR |
1458 | } |
1459 | ||
697f0a48 | 1460 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
1461 | set_task_cpu(next_task, lowest_rq->cpu); |
1462 | activate_task(lowest_rq, next_task, 0); | |
1463 | ||
1464 | resched_task(lowest_rq->curr); | |
1465 | ||
1b12bbc7 | 1466 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 | 1467 | |
e8fa1362 SR |
1468 | out: |
1469 | put_task_struct(next_task); | |
1470 | ||
917b627d | 1471 | return 1; |
e8fa1362 SR |
1472 | } |
1473 | ||
e8fa1362 SR |
1474 | static void push_rt_tasks(struct rq *rq) |
1475 | { | |
1476 | /* push_rt_task will return true if it moved an RT */ | |
1477 | while (push_rt_task(rq)) | |
1478 | ; | |
1479 | } | |
1480 | ||
f65eda4f SR |
1481 | static int pull_rt_task(struct rq *this_rq) |
1482 | { | |
80bf3171 | 1483 | int this_cpu = this_rq->cpu, ret = 0, cpu; |
a8728944 | 1484 | struct task_struct *p; |
f65eda4f | 1485 | struct rq *src_rq; |
f65eda4f | 1486 | |
637f5085 | 1487 | if (likely(!rt_overloaded(this_rq))) |
f65eda4f SR |
1488 | return 0; |
1489 | ||
c6c4927b | 1490 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
1491 | if (this_cpu == cpu) |
1492 | continue; | |
1493 | ||
1494 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
1495 | |
1496 | /* | |
1497 | * Don't bother taking the src_rq->lock if the next highest | |
1498 | * task is known to be lower-priority than our current task. | |
1499 | * This may look racy, but if this value is about to go | |
1500 | * logically higher, the src_rq will push this task away. | |
1501 | * And if its going logically lower, we do not care | |
1502 | */ | |
1503 | if (src_rq->rt.highest_prio.next >= | |
1504 | this_rq->rt.highest_prio.curr) | |
1505 | continue; | |
1506 | ||
f65eda4f SR |
1507 | /* |
1508 | * We can potentially drop this_rq's lock in | |
1509 | * double_lock_balance, and another CPU could | |
a8728944 | 1510 | * alter this_rq |
f65eda4f | 1511 | */ |
a8728944 | 1512 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
1513 | |
1514 | /* | |
1515 | * Are there still pullable RT tasks? | |
1516 | */ | |
614ee1f6 MG |
1517 | if (src_rq->rt.rt_nr_running <= 1) |
1518 | goto skip; | |
f65eda4f | 1519 | |
f65eda4f SR |
1520 | p = pick_next_highest_task_rt(src_rq, this_cpu); |
1521 | ||
1522 | /* | |
1523 | * Do we have an RT task that preempts | |
1524 | * the to-be-scheduled task? | |
1525 | */ | |
a8728944 | 1526 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f | 1527 | WARN_ON(p == src_rq->curr); |
fd2f4419 | 1528 | WARN_ON(!p->on_rq); |
f65eda4f SR |
1529 | |
1530 | /* | |
1531 | * There's a chance that p is higher in priority | |
1532 | * than what's currently running on its cpu. | |
1533 | * This is just that p is wakeing up and hasn't | |
1534 | * had a chance to schedule. We only pull | |
1535 | * p if it is lower in priority than the | |
a8728944 | 1536 | * current task on the run queue |
f65eda4f | 1537 | */ |
a8728944 | 1538 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 1539 | goto skip; |
f65eda4f SR |
1540 | |
1541 | ret = 1; | |
1542 | ||
1543 | deactivate_task(src_rq, p, 0); | |
1544 | set_task_cpu(p, this_cpu); | |
1545 | activate_task(this_rq, p, 0); | |
1546 | /* | |
1547 | * We continue with the search, just in | |
1548 | * case there's an even higher prio task | |
25985edc | 1549 | * in another runqueue. (low likelihood |
f65eda4f | 1550 | * but possible) |
f65eda4f | 1551 | */ |
f65eda4f | 1552 | } |
49246274 | 1553 | skip: |
1b12bbc7 | 1554 | double_unlock_balance(this_rq, src_rq); |
f65eda4f SR |
1555 | } |
1556 | ||
1557 | return ret; | |
1558 | } | |
1559 | ||
9a897c5a | 1560 | static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) |
f65eda4f SR |
1561 | { |
1562 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
33c3d6c6 | 1563 | if (rq->rt.highest_prio.curr > prev->prio) |
f65eda4f SR |
1564 | pull_rt_task(rq); |
1565 | } | |
1566 | ||
9a897c5a | 1567 | static void post_schedule_rt(struct rq *rq) |
e8fa1362 | 1568 | { |
967fc046 | 1569 | push_rt_tasks(rq); |
e8fa1362 SR |
1570 | } |
1571 | ||
8ae121ac GH |
1572 | /* |
1573 | * If we are not running and we are not going to reschedule soon, we should | |
1574 | * try to push tasks away now | |
1575 | */ | |
efbbd05a | 1576 | static void task_woken_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 1577 | { |
9a897c5a | 1578 | if (!task_running(rq, p) && |
8ae121ac | 1579 | !test_tsk_need_resched(rq->curr) && |
917b627d | 1580 | has_pushable_tasks(rq) && |
b3bc211c | 1581 | p->rt.nr_cpus_allowed > 1 && |
43fa5460 | 1582 | rt_task(rq->curr) && |
b3bc211c SR |
1583 | (rq->curr->rt.nr_cpus_allowed < 2 || |
1584 | rq->curr->prio < p->prio)) | |
4642dafd SR |
1585 | push_rt_tasks(rq); |
1586 | } | |
1587 | ||
cd8ba7cd | 1588 | static void set_cpus_allowed_rt(struct task_struct *p, |
96f874e2 | 1589 | const struct cpumask *new_mask) |
73fe6aae | 1590 | { |
96f874e2 | 1591 | int weight = cpumask_weight(new_mask); |
73fe6aae GH |
1592 | |
1593 | BUG_ON(!rt_task(p)); | |
1594 | ||
1595 | /* | |
1596 | * Update the migration status of the RQ if we have an RT task | |
1597 | * which is running AND changing its weight value. | |
1598 | */ | |
fd2f4419 | 1599 | if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) { |
73fe6aae GH |
1600 | struct rq *rq = task_rq(p); |
1601 | ||
917b627d GH |
1602 | if (!task_current(rq, p)) { |
1603 | /* | |
1604 | * Make sure we dequeue this task from the pushable list | |
1605 | * before going further. It will either remain off of | |
1606 | * the list because we are no longer pushable, or it | |
1607 | * will be requeued. | |
1608 | */ | |
1609 | if (p->rt.nr_cpus_allowed > 1) | |
1610 | dequeue_pushable_task(rq, p); | |
1611 | ||
1612 | /* | |
1613 | * Requeue if our weight is changing and still > 1 | |
1614 | */ | |
1615 | if (weight > 1) | |
1616 | enqueue_pushable_task(rq, p); | |
1617 | ||
1618 | } | |
1619 | ||
6f505b16 | 1620 | if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { |
73fe6aae | 1621 | rq->rt.rt_nr_migratory++; |
6f505b16 | 1622 | } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { |
73fe6aae GH |
1623 | BUG_ON(!rq->rt.rt_nr_migratory); |
1624 | rq->rt.rt_nr_migratory--; | |
1625 | } | |
1626 | ||
398a153b | 1627 | update_rt_migration(&rq->rt); |
73fe6aae GH |
1628 | } |
1629 | ||
96f874e2 | 1630 | cpumask_copy(&p->cpus_allowed, new_mask); |
6f505b16 | 1631 | p->rt.nr_cpus_allowed = weight; |
73fe6aae | 1632 | } |
deeeccd4 | 1633 | |
bdd7c81b | 1634 | /* Assumes rq->lock is held */ |
1f11eb6a | 1635 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
1636 | { |
1637 | if (rq->rt.overloaded) | |
1638 | rt_set_overload(rq); | |
6e0534f2 | 1639 | |
7def2be1 PZ |
1640 | __enable_runtime(rq); |
1641 | ||
e864c499 | 1642 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
1643 | } |
1644 | ||
1645 | /* Assumes rq->lock is held */ | |
1f11eb6a | 1646 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
1647 | { |
1648 | if (rq->rt.overloaded) | |
1649 | rt_clear_overload(rq); | |
6e0534f2 | 1650 | |
7def2be1 PZ |
1651 | __disable_runtime(rq); |
1652 | ||
6e0534f2 | 1653 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 1654 | } |
cb469845 SR |
1655 | |
1656 | /* | |
1657 | * When switch from the rt queue, we bring ourselves to a position | |
1658 | * that we might want to pull RT tasks from other runqueues. | |
1659 | */ | |
da7a735e | 1660 | static void switched_from_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
1661 | { |
1662 | /* | |
1663 | * If there are other RT tasks then we will reschedule | |
1664 | * and the scheduling of the other RT tasks will handle | |
1665 | * the balancing. But if we are the last RT task | |
1666 | * we may need to handle the pulling of RT tasks | |
1667 | * now. | |
1668 | */ | |
fd2f4419 | 1669 | if (p->on_rq && !rq->rt.rt_nr_running) |
cb469845 SR |
1670 | pull_rt_task(rq); |
1671 | } | |
3d8cbdf8 RR |
1672 | |
1673 | static inline void init_sched_rt_class(void) | |
1674 | { | |
1675 | unsigned int i; | |
1676 | ||
1677 | for_each_possible_cpu(i) | |
eaa95840 | 1678 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
6ca09dfc | 1679 | GFP_KERNEL, cpu_to_node(i)); |
3d8cbdf8 | 1680 | } |
cb469845 SR |
1681 | #endif /* CONFIG_SMP */ |
1682 | ||
1683 | /* | |
1684 | * When switching a task to RT, we may overload the runqueue | |
1685 | * with RT tasks. In this case we try to push them off to | |
1686 | * other runqueues. | |
1687 | */ | |
da7a735e | 1688 | static void switched_to_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
1689 | { |
1690 | int check_resched = 1; | |
1691 | ||
1692 | /* | |
1693 | * If we are already running, then there's nothing | |
1694 | * that needs to be done. But if we are not running | |
1695 | * we may need to preempt the current running task. | |
1696 | * If that current running task is also an RT task | |
1697 | * then see if we can move to another run queue. | |
1698 | */ | |
fd2f4419 | 1699 | if (p->on_rq && rq->curr != p) { |
cb469845 SR |
1700 | #ifdef CONFIG_SMP |
1701 | if (rq->rt.overloaded && push_rt_task(rq) && | |
1702 | /* Don't resched if we changed runqueues */ | |
1703 | rq != task_rq(p)) | |
1704 | check_resched = 0; | |
1705 | #endif /* CONFIG_SMP */ | |
1706 | if (check_resched && p->prio < rq->curr->prio) | |
1707 | resched_task(rq->curr); | |
1708 | } | |
1709 | } | |
1710 | ||
1711 | /* | |
1712 | * Priority of the task has changed. This may cause | |
1713 | * us to initiate a push or pull. | |
1714 | */ | |
da7a735e PZ |
1715 | static void |
1716 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 1717 | { |
fd2f4419 | 1718 | if (!p->on_rq) |
da7a735e PZ |
1719 | return; |
1720 | ||
1721 | if (rq->curr == p) { | |
cb469845 SR |
1722 | #ifdef CONFIG_SMP |
1723 | /* | |
1724 | * If our priority decreases while running, we | |
1725 | * may need to pull tasks to this runqueue. | |
1726 | */ | |
1727 | if (oldprio < p->prio) | |
1728 | pull_rt_task(rq); | |
1729 | /* | |
1730 | * If there's a higher priority task waiting to run | |
6fa46fa5 SR |
1731 | * then reschedule. Note, the above pull_rt_task |
1732 | * can release the rq lock and p could migrate. | |
1733 | * Only reschedule if p is still on the same runqueue. | |
cb469845 | 1734 | */ |
e864c499 | 1735 | if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) |
cb469845 SR |
1736 | resched_task(p); |
1737 | #else | |
1738 | /* For UP simply resched on drop of prio */ | |
1739 | if (oldprio < p->prio) | |
1740 | resched_task(p); | |
e8fa1362 | 1741 | #endif /* CONFIG_SMP */ |
cb469845 SR |
1742 | } else { |
1743 | /* | |
1744 | * This task is not running, but if it is | |
1745 | * greater than the current running task | |
1746 | * then reschedule. | |
1747 | */ | |
1748 | if (p->prio < rq->curr->prio) | |
1749 | resched_task(rq->curr); | |
1750 | } | |
1751 | } | |
1752 | ||
78f2c7db PZ |
1753 | static void watchdog(struct rq *rq, struct task_struct *p) |
1754 | { | |
1755 | unsigned long soft, hard; | |
1756 | ||
78d7d407 JS |
1757 | /* max may change after cur was read, this will be fixed next tick */ |
1758 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
1759 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
78f2c7db PZ |
1760 | |
1761 | if (soft != RLIM_INFINITY) { | |
1762 | unsigned long next; | |
1763 | ||
1764 | p->rt.timeout++; | |
1765 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); | |
5a52dd50 | 1766 | if (p->rt.timeout > next) |
f06febc9 | 1767 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
78f2c7db PZ |
1768 | } |
1769 | } | |
bb44e5d1 | 1770 | |
8f4d37ec | 1771 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 1772 | { |
67e2be02 PZ |
1773 | update_curr_rt(rq); |
1774 | ||
78f2c7db PZ |
1775 | watchdog(rq, p); |
1776 | ||
bb44e5d1 IM |
1777 | /* |
1778 | * RR tasks need a special form of timeslice management. | |
1779 | * FIFO tasks have no timeslices. | |
1780 | */ | |
1781 | if (p->policy != SCHED_RR) | |
1782 | return; | |
1783 | ||
fa717060 | 1784 | if (--p->rt.time_slice) |
bb44e5d1 IM |
1785 | return; |
1786 | ||
fa717060 | 1787 | p->rt.time_slice = DEF_TIMESLICE; |
bb44e5d1 | 1788 | |
98fbc798 DA |
1789 | /* |
1790 | * Requeue to the end of queue if we are not the only element | |
1791 | * on the queue: | |
1792 | */ | |
fa717060 | 1793 | if (p->rt.run_list.prev != p->rt.run_list.next) { |
7ebefa8c | 1794 | requeue_task_rt(rq, p, 0); |
98fbc798 DA |
1795 | set_tsk_need_resched(p); |
1796 | } | |
bb44e5d1 IM |
1797 | } |
1798 | ||
83b699ed SV |
1799 | static void set_curr_task_rt(struct rq *rq) |
1800 | { | |
1801 | struct task_struct *p = rq->curr; | |
1802 | ||
305e6835 | 1803 | p->se.exec_start = rq->clock_task; |
917b627d GH |
1804 | |
1805 | /* The running task is never eligible for pushing */ | |
1806 | dequeue_pushable_task(rq, p); | |
83b699ed SV |
1807 | } |
1808 | ||
6d686f45 | 1809 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) |
0d721cea PW |
1810 | { |
1811 | /* | |
1812 | * Time slice is 0 for SCHED_FIFO tasks | |
1813 | */ | |
1814 | if (task->policy == SCHED_RR) | |
1815 | return DEF_TIMESLICE; | |
1816 | else | |
1817 | return 0; | |
1818 | } | |
1819 | ||
2abdad0a | 1820 | static const struct sched_class rt_sched_class = { |
5522d5d5 | 1821 | .next = &fair_sched_class, |
bb44e5d1 IM |
1822 | .enqueue_task = enqueue_task_rt, |
1823 | .dequeue_task = dequeue_task_rt, | |
1824 | .yield_task = yield_task_rt, | |
1825 | ||
1826 | .check_preempt_curr = check_preempt_curr_rt, | |
1827 | ||
1828 | .pick_next_task = pick_next_task_rt, | |
1829 | .put_prev_task = put_prev_task_rt, | |
1830 | ||
681f3e68 | 1831 | #ifdef CONFIG_SMP |
4ce72a2c LZ |
1832 | .select_task_rq = select_task_rq_rt, |
1833 | ||
73fe6aae | 1834 | .set_cpus_allowed = set_cpus_allowed_rt, |
1f11eb6a GH |
1835 | .rq_online = rq_online_rt, |
1836 | .rq_offline = rq_offline_rt, | |
9a897c5a SR |
1837 | .pre_schedule = pre_schedule_rt, |
1838 | .post_schedule = post_schedule_rt, | |
efbbd05a | 1839 | .task_woken = task_woken_rt, |
cb469845 | 1840 | .switched_from = switched_from_rt, |
681f3e68 | 1841 | #endif |
bb44e5d1 | 1842 | |
83b699ed | 1843 | .set_curr_task = set_curr_task_rt, |
bb44e5d1 | 1844 | .task_tick = task_tick_rt, |
cb469845 | 1845 | |
0d721cea PW |
1846 | .get_rr_interval = get_rr_interval_rt, |
1847 | ||
cb469845 SR |
1848 | .prio_changed = prio_changed_rt, |
1849 | .switched_to = switched_to_rt, | |
bb44e5d1 | 1850 | }; |
ada18de2 PZ |
1851 | |
1852 | #ifdef CONFIG_SCHED_DEBUG | |
1853 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
1854 | ||
1855 | static void print_rt_stats(struct seq_file *m, int cpu) | |
1856 | { | |
ec514c48 | 1857 | rt_rq_iter_t iter; |
ada18de2 PZ |
1858 | struct rt_rq *rt_rq; |
1859 | ||
1860 | rcu_read_lock(); | |
ec514c48 | 1861 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) |
ada18de2 PZ |
1862 | print_rt_rq(m, cpu, rt_rq); |
1863 | rcu_read_unlock(); | |
1864 | } | |
55e12e5e | 1865 | #endif /* CONFIG_SCHED_DEBUG */ |
0e3900e6 | 1866 |