Commit | Line | Data |
---|---|---|
bb44e5d1 IM |
1 | /* |
2 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR | |
3 | * policies) | |
4 | */ | |
5 | ||
398a153b GH |
6 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
7 | { | |
8 | return container_of(rt_se, struct task_struct, rt); | |
9 | } | |
10 | ||
11 | #ifdef CONFIG_RT_GROUP_SCHED | |
12 | ||
13 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) | |
14 | { | |
15 | return rt_rq->rq; | |
16 | } | |
17 | ||
18 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
19 | { | |
20 | return rt_se->rt_rq; | |
21 | } | |
22 | ||
23 | #else /* CONFIG_RT_GROUP_SCHED */ | |
24 | ||
25 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) | |
26 | { | |
27 | return container_of(rt_rq, struct rq, rt); | |
28 | } | |
29 | ||
30 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
31 | { | |
32 | struct task_struct *p = rt_task_of(rt_se); | |
33 | struct rq *rq = task_rq(p); | |
34 | ||
35 | return &rq->rt; | |
36 | } | |
37 | ||
38 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
39 | ||
4fd29176 | 40 | #ifdef CONFIG_SMP |
84de4274 | 41 | |
637f5085 | 42 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 43 | { |
637f5085 | 44 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 45 | } |
84de4274 | 46 | |
4fd29176 SR |
47 | static inline void rt_set_overload(struct rq *rq) |
48 | { | |
1f11eb6a GH |
49 | if (!rq->online) |
50 | return; | |
51 | ||
c6c4927b | 52 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
53 | /* |
54 | * Make sure the mask is visible before we set | |
55 | * the overload count. That is checked to determine | |
56 | * if we should look at the mask. It would be a shame | |
57 | * if we looked at the mask, but the mask was not | |
58 | * updated yet. | |
59 | */ | |
60 | wmb(); | |
637f5085 | 61 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 62 | } |
84de4274 | 63 | |
4fd29176 SR |
64 | static inline void rt_clear_overload(struct rq *rq) |
65 | { | |
1f11eb6a GH |
66 | if (!rq->online) |
67 | return; | |
68 | ||
4fd29176 | 69 | /* the order here really doesn't matter */ |
637f5085 | 70 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 71 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 72 | } |
73fe6aae | 73 | |
398a153b | 74 | static void update_rt_migration(struct rt_rq *rt_rq) |
73fe6aae | 75 | { |
398a153b GH |
76 | if (rt_rq->rt_nr_migratory && (rt_rq->rt_nr_running > 1)) { |
77 | if (!rt_rq->overloaded) { | |
78 | rt_set_overload(rq_of_rt_rq(rt_rq)); | |
79 | rt_rq->overloaded = 1; | |
cdc8eb98 | 80 | } |
398a153b GH |
81 | } else if (rt_rq->overloaded) { |
82 | rt_clear_overload(rq_of_rt_rq(rt_rq)); | |
83 | rt_rq->overloaded = 0; | |
637f5085 | 84 | } |
73fe6aae | 85 | } |
4fd29176 | 86 | |
398a153b GH |
87 | static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
88 | { | |
89 | if (rt_se->nr_cpus_allowed > 1) | |
90 | rt_rq->rt_nr_migratory++; | |
91 | ||
92 | update_rt_migration(rt_rq); | |
93 | } | |
94 | ||
95 | static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
96 | { | |
97 | if (rt_se->nr_cpus_allowed > 1) | |
98 | rt_rq->rt_nr_migratory--; | |
99 | ||
100 | update_rt_migration(rt_rq); | |
101 | } | |
102 | ||
917b627d GH |
103 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
104 | { | |
105 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
106 | plist_node_init(&p->pushable_tasks, p->prio); | |
107 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
108 | } | |
109 | ||
110 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
111 | { | |
112 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
113 | } | |
114 | ||
115 | #else | |
116 | ||
ceacc2c1 | 117 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
fa85ae24 | 118 | { |
6f505b16 PZ |
119 | } |
120 | ||
ceacc2c1 PZ |
121 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
122 | { | |
123 | } | |
124 | ||
b07430ac | 125 | static inline |
ceacc2c1 PZ |
126 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
127 | { | |
128 | } | |
129 | ||
398a153b | 130 | static inline |
ceacc2c1 PZ |
131 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
132 | { | |
133 | } | |
917b627d | 134 | |
4fd29176 SR |
135 | #endif /* CONFIG_SMP */ |
136 | ||
6f505b16 PZ |
137 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
138 | { | |
139 | return !list_empty(&rt_se->run_list); | |
140 | } | |
141 | ||
052f1dc7 | 142 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 143 | |
9f0c1e56 | 144 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
145 | { |
146 | if (!rt_rq->tg) | |
9f0c1e56 | 147 | return RUNTIME_INF; |
6f505b16 | 148 | |
ac086bc2 PZ |
149 | return rt_rq->rt_runtime; |
150 | } | |
151 | ||
152 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
153 | { | |
154 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
155 | } |
156 | ||
157 | #define for_each_leaf_rt_rq(rt_rq, rq) \ | |
80f40ee4 | 158 | list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) |
6f505b16 | 159 | |
6f505b16 PZ |
160 | #define for_each_sched_rt_entity(rt_se) \ |
161 | for (; rt_se; rt_se = rt_se->parent) | |
162 | ||
163 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
164 | { | |
165 | return rt_se->my_q; | |
166 | } | |
167 | ||
168 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se); | |
169 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se); | |
170 | ||
9f0c1e56 | 171 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 172 | { |
f6121f4f | 173 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
6f505b16 PZ |
174 | struct sched_rt_entity *rt_se = rt_rq->rt_se; |
175 | ||
f6121f4f DF |
176 | if (rt_rq->rt_nr_running) { |
177 | if (rt_se && !on_rt_rq(rt_se)) | |
178 | enqueue_rt_entity(rt_se); | |
e864c499 | 179 | if (rt_rq->highest_prio.curr < curr->prio) |
1020387f | 180 | resched_task(curr); |
6f505b16 PZ |
181 | } |
182 | } | |
183 | ||
9f0c1e56 | 184 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
185 | { |
186 | struct sched_rt_entity *rt_se = rt_rq->rt_se; | |
187 | ||
188 | if (rt_se && on_rt_rq(rt_se)) | |
189 | dequeue_rt_entity(rt_se); | |
190 | } | |
191 | ||
23b0fdfc PZ |
192 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
193 | { | |
194 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
195 | } | |
196 | ||
197 | static int rt_se_boosted(struct sched_rt_entity *rt_se) | |
198 | { | |
199 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
200 | struct task_struct *p; | |
201 | ||
202 | if (rt_rq) | |
203 | return !!rt_rq->rt_nr_boosted; | |
204 | ||
205 | p = rt_task_of(rt_se); | |
206 | return p->prio != p->normal_prio; | |
207 | } | |
208 | ||
d0b27fa7 | 209 | #ifdef CONFIG_SMP |
c6c4927b | 210 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 PZ |
211 | { |
212 | return cpu_rq(smp_processor_id())->rd->span; | |
213 | } | |
6f505b16 | 214 | #else |
c6c4927b | 215 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 216 | { |
c6c4927b | 217 | return cpu_online_mask; |
d0b27fa7 PZ |
218 | } |
219 | #endif | |
6f505b16 | 220 | |
d0b27fa7 PZ |
221 | static inline |
222 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 223 | { |
d0b27fa7 PZ |
224 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
225 | } | |
9f0c1e56 | 226 | |
ac086bc2 PZ |
227 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
228 | { | |
229 | return &rt_rq->tg->rt_bandwidth; | |
230 | } | |
231 | ||
55e12e5e | 232 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
233 | |
234 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
235 | { | |
ac086bc2 PZ |
236 | return rt_rq->rt_runtime; |
237 | } | |
238 | ||
239 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
240 | { | |
241 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
242 | } |
243 | ||
244 | #define for_each_leaf_rt_rq(rt_rq, rq) \ | |
245 | for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
246 | ||
6f505b16 PZ |
247 | #define for_each_sched_rt_entity(rt_se) \ |
248 | for (; rt_se; rt_se = NULL) | |
249 | ||
250 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
251 | { | |
252 | return NULL; | |
253 | } | |
254 | ||
9f0c1e56 | 255 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 256 | { |
f3ade837 JB |
257 | if (rt_rq->rt_nr_running) |
258 | resched_task(rq_of_rt_rq(rt_rq)->curr); | |
6f505b16 PZ |
259 | } |
260 | ||
9f0c1e56 | 261 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
262 | { |
263 | } | |
264 | ||
23b0fdfc PZ |
265 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
266 | { | |
267 | return rt_rq->rt_throttled; | |
268 | } | |
d0b27fa7 | 269 | |
c6c4927b | 270 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 271 | { |
c6c4927b | 272 | return cpu_online_mask; |
d0b27fa7 PZ |
273 | } |
274 | ||
275 | static inline | |
276 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
277 | { | |
278 | return &cpu_rq(cpu)->rt; | |
279 | } | |
280 | ||
ac086bc2 PZ |
281 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
282 | { | |
283 | return &def_rt_bandwidth; | |
284 | } | |
285 | ||
55e12e5e | 286 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 287 | |
ac086bc2 | 288 | #ifdef CONFIG_SMP |
78333cdd PZ |
289 | /* |
290 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
291 | */ | |
b79f3833 | 292 | static int do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
293 | { |
294 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
295 | struct root_domain *rd = cpu_rq(smp_processor_id())->rd; | |
296 | int i, weight, more = 0; | |
297 | u64 rt_period; | |
298 | ||
c6c4927b | 299 | weight = cpumask_weight(rd->span); |
ac086bc2 PZ |
300 | |
301 | spin_lock(&rt_b->rt_runtime_lock); | |
302 | rt_period = ktime_to_ns(rt_b->rt_period); | |
c6c4927b | 303 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
304 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
305 | s64 diff; | |
306 | ||
307 | if (iter == rt_rq) | |
308 | continue; | |
309 | ||
310 | spin_lock(&iter->rt_runtime_lock); | |
78333cdd PZ |
311 | /* |
312 | * Either all rqs have inf runtime and there's nothing to steal | |
313 | * or __disable_runtime() below sets a specific rq to inf to | |
314 | * indicate its been disabled and disalow stealing. | |
315 | */ | |
7def2be1 PZ |
316 | if (iter->rt_runtime == RUNTIME_INF) |
317 | goto next; | |
318 | ||
78333cdd PZ |
319 | /* |
320 | * From runqueues with spare time, take 1/n part of their | |
321 | * spare time, but no more than our period. | |
322 | */ | |
ac086bc2 PZ |
323 | diff = iter->rt_runtime - iter->rt_time; |
324 | if (diff > 0) { | |
58838cf3 | 325 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
326 | if (rt_rq->rt_runtime + diff > rt_period) |
327 | diff = rt_period - rt_rq->rt_runtime; | |
328 | iter->rt_runtime -= diff; | |
329 | rt_rq->rt_runtime += diff; | |
330 | more = 1; | |
331 | if (rt_rq->rt_runtime == rt_period) { | |
332 | spin_unlock(&iter->rt_runtime_lock); | |
333 | break; | |
334 | } | |
335 | } | |
7def2be1 | 336 | next: |
ac086bc2 PZ |
337 | spin_unlock(&iter->rt_runtime_lock); |
338 | } | |
339 | spin_unlock(&rt_b->rt_runtime_lock); | |
340 | ||
341 | return more; | |
342 | } | |
7def2be1 | 343 | |
78333cdd PZ |
344 | /* |
345 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
346 | */ | |
7def2be1 PZ |
347 | static void __disable_runtime(struct rq *rq) |
348 | { | |
349 | struct root_domain *rd = rq->rd; | |
350 | struct rt_rq *rt_rq; | |
351 | ||
352 | if (unlikely(!scheduler_running)) | |
353 | return; | |
354 | ||
355 | for_each_leaf_rt_rq(rt_rq, rq) { | |
356 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
357 | s64 want; | |
358 | int i; | |
359 | ||
360 | spin_lock(&rt_b->rt_runtime_lock); | |
361 | spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
362 | /* |
363 | * Either we're all inf and nobody needs to borrow, or we're | |
364 | * already disabled and thus have nothing to do, or we have | |
365 | * exactly the right amount of runtime to take out. | |
366 | */ | |
7def2be1 PZ |
367 | if (rt_rq->rt_runtime == RUNTIME_INF || |
368 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
369 | goto balanced; | |
370 | spin_unlock(&rt_rq->rt_runtime_lock); | |
371 | ||
78333cdd PZ |
372 | /* |
373 | * Calculate the difference between what we started out with | |
374 | * and what we current have, that's the amount of runtime | |
375 | * we lend and now have to reclaim. | |
376 | */ | |
7def2be1 PZ |
377 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
378 | ||
78333cdd PZ |
379 | /* |
380 | * Greedy reclaim, take back as much as we can. | |
381 | */ | |
c6c4927b | 382 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
383 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
384 | s64 diff; | |
385 | ||
78333cdd PZ |
386 | /* |
387 | * Can't reclaim from ourselves or disabled runqueues. | |
388 | */ | |
f1679d08 | 389 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
390 | continue; |
391 | ||
392 | spin_lock(&iter->rt_runtime_lock); | |
393 | if (want > 0) { | |
394 | diff = min_t(s64, iter->rt_runtime, want); | |
395 | iter->rt_runtime -= diff; | |
396 | want -= diff; | |
397 | } else { | |
398 | iter->rt_runtime -= want; | |
399 | want -= want; | |
400 | } | |
401 | spin_unlock(&iter->rt_runtime_lock); | |
402 | ||
403 | if (!want) | |
404 | break; | |
405 | } | |
406 | ||
407 | spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
408 | /* |
409 | * We cannot be left wanting - that would mean some runtime | |
410 | * leaked out of the system. | |
411 | */ | |
7def2be1 PZ |
412 | BUG_ON(want); |
413 | balanced: | |
78333cdd PZ |
414 | /* |
415 | * Disable all the borrow logic by pretending we have inf | |
416 | * runtime - in which case borrowing doesn't make sense. | |
417 | */ | |
7def2be1 PZ |
418 | rt_rq->rt_runtime = RUNTIME_INF; |
419 | spin_unlock(&rt_rq->rt_runtime_lock); | |
420 | spin_unlock(&rt_b->rt_runtime_lock); | |
421 | } | |
422 | } | |
423 | ||
424 | static void disable_runtime(struct rq *rq) | |
425 | { | |
426 | unsigned long flags; | |
427 | ||
428 | spin_lock_irqsave(&rq->lock, flags); | |
429 | __disable_runtime(rq); | |
430 | spin_unlock_irqrestore(&rq->lock, flags); | |
431 | } | |
432 | ||
433 | static void __enable_runtime(struct rq *rq) | |
434 | { | |
7def2be1 PZ |
435 | struct rt_rq *rt_rq; |
436 | ||
437 | if (unlikely(!scheduler_running)) | |
438 | return; | |
439 | ||
78333cdd PZ |
440 | /* |
441 | * Reset each runqueue's bandwidth settings | |
442 | */ | |
7def2be1 PZ |
443 | for_each_leaf_rt_rq(rt_rq, rq) { |
444 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
445 | ||
446 | spin_lock(&rt_b->rt_runtime_lock); | |
447 | spin_lock(&rt_rq->rt_runtime_lock); | |
448 | rt_rq->rt_runtime = rt_b->rt_runtime; | |
449 | rt_rq->rt_time = 0; | |
baf25731 | 450 | rt_rq->rt_throttled = 0; |
7def2be1 PZ |
451 | spin_unlock(&rt_rq->rt_runtime_lock); |
452 | spin_unlock(&rt_b->rt_runtime_lock); | |
453 | } | |
454 | } | |
455 | ||
456 | static void enable_runtime(struct rq *rq) | |
457 | { | |
458 | unsigned long flags; | |
459 | ||
460 | spin_lock_irqsave(&rq->lock, flags); | |
461 | __enable_runtime(rq); | |
462 | spin_unlock_irqrestore(&rq->lock, flags); | |
463 | } | |
464 | ||
eff6549b PZ |
465 | static int balance_runtime(struct rt_rq *rt_rq) |
466 | { | |
467 | int more = 0; | |
468 | ||
469 | if (rt_rq->rt_time > rt_rq->rt_runtime) { | |
470 | spin_unlock(&rt_rq->rt_runtime_lock); | |
471 | more = do_balance_runtime(rt_rq); | |
472 | spin_lock(&rt_rq->rt_runtime_lock); | |
473 | } | |
474 | ||
475 | return more; | |
476 | } | |
55e12e5e | 477 | #else /* !CONFIG_SMP */ |
eff6549b PZ |
478 | static inline int balance_runtime(struct rt_rq *rt_rq) |
479 | { | |
480 | return 0; | |
481 | } | |
55e12e5e | 482 | #endif /* CONFIG_SMP */ |
ac086bc2 | 483 | |
eff6549b PZ |
484 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
485 | { | |
486 | int i, idle = 1; | |
c6c4927b | 487 | const struct cpumask *span; |
eff6549b | 488 | |
0b148fa0 | 489 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
eff6549b PZ |
490 | return 1; |
491 | ||
492 | span = sched_rt_period_mask(); | |
c6c4927b | 493 | for_each_cpu(i, span) { |
eff6549b PZ |
494 | int enqueue = 0; |
495 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
496 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
497 | ||
498 | spin_lock(&rq->lock); | |
499 | if (rt_rq->rt_time) { | |
500 | u64 runtime; | |
501 | ||
502 | spin_lock(&rt_rq->rt_runtime_lock); | |
503 | if (rt_rq->rt_throttled) | |
504 | balance_runtime(rt_rq); | |
505 | runtime = rt_rq->rt_runtime; | |
506 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
507 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
508 | rt_rq->rt_throttled = 0; | |
509 | enqueue = 1; | |
510 | } | |
511 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
512 | idle = 0; | |
513 | spin_unlock(&rt_rq->rt_runtime_lock); | |
6c3df255 PZ |
514 | } else if (rt_rq->rt_nr_running) |
515 | idle = 0; | |
eff6549b PZ |
516 | |
517 | if (enqueue) | |
518 | sched_rt_rq_enqueue(rt_rq); | |
519 | spin_unlock(&rq->lock); | |
520 | } | |
521 | ||
522 | return idle; | |
523 | } | |
ac086bc2 | 524 | |
6f505b16 PZ |
525 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
526 | { | |
052f1dc7 | 527 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
528 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
529 | ||
530 | if (rt_rq) | |
e864c499 | 531 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
532 | #endif |
533 | ||
534 | return rt_task_of(rt_se)->prio; | |
535 | } | |
536 | ||
9f0c1e56 | 537 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 538 | { |
9f0c1e56 | 539 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 540 | |
fa85ae24 | 541 | if (rt_rq->rt_throttled) |
23b0fdfc | 542 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 543 | |
ac086bc2 PZ |
544 | if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) |
545 | return 0; | |
546 | ||
b79f3833 PZ |
547 | balance_runtime(rt_rq); |
548 | runtime = sched_rt_runtime(rt_rq); | |
549 | if (runtime == RUNTIME_INF) | |
550 | return 0; | |
ac086bc2 | 551 | |
9f0c1e56 | 552 | if (rt_rq->rt_time > runtime) { |
6f505b16 | 553 | rt_rq->rt_throttled = 1; |
23b0fdfc | 554 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 555 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
556 | return 1; |
557 | } | |
fa85ae24 PZ |
558 | } |
559 | ||
560 | return 0; | |
561 | } | |
562 | ||
bb44e5d1 IM |
563 | /* |
564 | * Update the current task's runtime statistics. Skip current tasks that | |
565 | * are not in our scheduling class. | |
566 | */ | |
a9957449 | 567 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
568 | { |
569 | struct task_struct *curr = rq->curr; | |
6f505b16 PZ |
570 | struct sched_rt_entity *rt_se = &curr->rt; |
571 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
bb44e5d1 IM |
572 | u64 delta_exec; |
573 | ||
574 | if (!task_has_rt_policy(curr)) | |
575 | return; | |
576 | ||
d281918d | 577 | delta_exec = rq->clock - curr->se.exec_start; |
bb44e5d1 IM |
578 | if (unlikely((s64)delta_exec < 0)) |
579 | delta_exec = 0; | |
6cfb0d5d IM |
580 | |
581 | schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); | |
bb44e5d1 IM |
582 | |
583 | curr->se.sum_exec_runtime += delta_exec; | |
f06febc9 FM |
584 | account_group_exec_runtime(curr, delta_exec); |
585 | ||
d281918d | 586 | curr->se.exec_start = rq->clock; |
d842de87 | 587 | cpuacct_charge(curr, delta_exec); |
fa85ae24 | 588 | |
0b148fa0 PZ |
589 | if (!rt_bandwidth_enabled()) |
590 | return; | |
591 | ||
354d60c2 DG |
592 | for_each_sched_rt_entity(rt_se) { |
593 | rt_rq = rt_rq_of_se(rt_se); | |
594 | ||
cc2991cf | 595 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
e113a745 | 596 | spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf PZ |
597 | rt_rq->rt_time += delta_exec; |
598 | if (sched_rt_runtime_exceeded(rt_rq)) | |
599 | resched_task(curr); | |
e113a745 | 600 | spin_unlock(&rt_rq->rt_runtime_lock); |
cc2991cf | 601 | } |
354d60c2 | 602 | } |
bb44e5d1 IM |
603 | } |
604 | ||
398a153b | 605 | #if defined CONFIG_SMP |
e864c499 GH |
606 | |
607 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu); | |
608 | ||
609 | static inline int next_prio(struct rq *rq) | |
63489e45 | 610 | { |
e864c499 GH |
611 | struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu); |
612 | ||
613 | if (next && rt_prio(next->prio)) | |
614 | return next->prio; | |
615 | else | |
616 | return MAX_RT_PRIO; | |
617 | } | |
e864c499 | 618 | |
398a153b GH |
619 | static void |
620 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 621 | { |
4d984277 | 622 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 623 | |
398a153b | 624 | if (prio < prev_prio) { |
4d984277 | 625 | |
e864c499 GH |
626 | /* |
627 | * If the new task is higher in priority than anything on the | |
398a153b GH |
628 | * run-queue, we know that the previous high becomes our |
629 | * next-highest. | |
e864c499 | 630 | */ |
398a153b | 631 | rt_rq->highest_prio.next = prev_prio; |
1f11eb6a GH |
632 | |
633 | if (rq->online) | |
4d984277 | 634 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); |
1100ac91 | 635 | |
e864c499 GH |
636 | } else if (prio == rt_rq->highest_prio.curr) |
637 | /* | |
638 | * If the next task is equal in priority to the highest on | |
639 | * the run-queue, then we implicitly know that the next highest | |
640 | * task cannot be any lower than current | |
641 | */ | |
642 | rt_rq->highest_prio.next = prio; | |
643 | else if (prio < rt_rq->highest_prio.next) | |
644 | /* | |
645 | * Otherwise, we need to recompute next-highest | |
646 | */ | |
647 | rt_rq->highest_prio.next = next_prio(rq); | |
398a153b | 648 | } |
73fe6aae | 649 | |
398a153b GH |
650 | static void |
651 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
652 | { | |
653 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 654 | |
398a153b GH |
655 | if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next)) |
656 | rt_rq->highest_prio.next = next_prio(rq); | |
657 | ||
658 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) | |
659 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
660 | } |
661 | ||
398a153b GH |
662 | #else /* CONFIG_SMP */ |
663 | ||
6f505b16 | 664 | static inline |
398a153b GH |
665 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
666 | static inline | |
667 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
668 | ||
669 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 670 | |
052f1dc7 | 671 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
672 | static void |
673 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
674 | { | |
675 | int prev_prio = rt_rq->highest_prio.curr; | |
676 | ||
677 | if (prio < prev_prio) | |
678 | rt_rq->highest_prio.curr = prio; | |
679 | ||
680 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
681 | } | |
682 | ||
683 | static void | |
684 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
685 | { | |
686 | int prev_prio = rt_rq->highest_prio.curr; | |
687 | ||
6f505b16 | 688 | if (rt_rq->rt_nr_running) { |
764a9d6f | 689 | |
398a153b | 690 | WARN_ON(prio < prev_prio); |
764a9d6f | 691 | |
e864c499 | 692 | /* |
398a153b GH |
693 | * This may have been our highest task, and therefore |
694 | * we may have some recomputation to do | |
e864c499 | 695 | */ |
398a153b | 696 | if (prio == prev_prio) { |
e864c499 GH |
697 | struct rt_prio_array *array = &rt_rq->active; |
698 | ||
699 | rt_rq->highest_prio.curr = | |
764a9d6f | 700 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
701 | } |
702 | ||
764a9d6f | 703 | } else |
e864c499 | 704 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
73fe6aae | 705 | |
398a153b GH |
706 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
707 | } | |
1f11eb6a | 708 | |
398a153b GH |
709 | #else |
710 | ||
711 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
712 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
713 | ||
714 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 715 | |
052f1dc7 | 716 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
717 | |
718 | static void | |
719 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
720 | { | |
721 | if (rt_se_boosted(rt_se)) | |
722 | rt_rq->rt_nr_boosted++; | |
723 | ||
724 | if (rt_rq->tg) | |
725 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
726 | } | |
727 | ||
728 | static void | |
729 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
730 | { | |
23b0fdfc PZ |
731 | if (rt_se_boosted(rt_se)) |
732 | rt_rq->rt_nr_boosted--; | |
733 | ||
734 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
398a153b GH |
735 | } |
736 | ||
737 | #else /* CONFIG_RT_GROUP_SCHED */ | |
738 | ||
739 | static void | |
740 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
741 | { | |
742 | start_rt_bandwidth(&def_rt_bandwidth); | |
743 | } | |
744 | ||
745 | static inline | |
746 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
747 | ||
748 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
749 | ||
750 | static inline | |
751 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
752 | { | |
753 | int prio = rt_se_prio(rt_se); | |
754 | ||
755 | WARN_ON(!rt_prio(prio)); | |
756 | rt_rq->rt_nr_running++; | |
757 | ||
758 | inc_rt_prio(rt_rq, prio); | |
759 | inc_rt_migration(rt_se, rt_rq); | |
760 | inc_rt_group(rt_se, rt_rq); | |
761 | } | |
762 | ||
763 | static inline | |
764 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
765 | { | |
766 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
767 | WARN_ON(!rt_rq->rt_nr_running); | |
768 | rt_rq->rt_nr_running--; | |
769 | ||
770 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
771 | dec_rt_migration(rt_se, rt_rq); | |
772 | dec_rt_group(rt_se, rt_rq); | |
63489e45 SR |
773 | } |
774 | ||
ad2a3f13 | 775 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) |
bb44e5d1 | 776 | { |
6f505b16 PZ |
777 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
778 | struct rt_prio_array *array = &rt_rq->active; | |
779 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 780 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 781 | |
ad2a3f13 PZ |
782 | /* |
783 | * Don't enqueue the group if its throttled, or when empty. | |
784 | * The latter is a consequence of the former when a child group | |
785 | * get throttled and the current group doesn't have any other | |
786 | * active members. | |
787 | */ | |
788 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) | |
6f505b16 | 789 | return; |
63489e45 | 790 | |
7ebefa8c | 791 | list_add_tail(&rt_se->run_list, queue); |
6f505b16 | 792 | __set_bit(rt_se_prio(rt_se), array->bitmap); |
78f2c7db | 793 | |
6f505b16 PZ |
794 | inc_rt_tasks(rt_se, rt_rq); |
795 | } | |
796 | ||
ad2a3f13 | 797 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) |
6f505b16 PZ |
798 | { |
799 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
800 | struct rt_prio_array *array = &rt_rq->active; | |
801 | ||
802 | list_del_init(&rt_se->run_list); | |
803 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
804 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
805 | ||
806 | dec_rt_tasks(rt_se, rt_rq); | |
807 | } | |
808 | ||
809 | /* | |
810 | * Because the prio of an upper entry depends on the lower | |
811 | * entries, we must remove entries top - down. | |
6f505b16 | 812 | */ |
ad2a3f13 | 813 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se) |
6f505b16 | 814 | { |
ad2a3f13 | 815 | struct sched_rt_entity *back = NULL; |
6f505b16 | 816 | |
58d6c2d7 PZ |
817 | for_each_sched_rt_entity(rt_se) { |
818 | rt_se->back = back; | |
819 | back = rt_se; | |
820 | } | |
821 | ||
822 | for (rt_se = back; rt_se; rt_se = rt_se->back) { | |
823 | if (on_rt_rq(rt_se)) | |
ad2a3f13 PZ |
824 | __dequeue_rt_entity(rt_se); |
825 | } | |
826 | } | |
827 | ||
828 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se) | |
829 | { | |
830 | dequeue_rt_stack(rt_se); | |
831 | for_each_sched_rt_entity(rt_se) | |
832 | __enqueue_rt_entity(rt_se); | |
833 | } | |
834 | ||
835 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se) | |
836 | { | |
837 | dequeue_rt_stack(rt_se); | |
838 | ||
839 | for_each_sched_rt_entity(rt_se) { | |
840 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
841 | ||
842 | if (rt_rq && rt_rq->rt_nr_running) | |
843 | __enqueue_rt_entity(rt_se); | |
58d6c2d7 | 844 | } |
bb44e5d1 IM |
845 | } |
846 | ||
847 | /* | |
848 | * Adding/removing a task to/from a priority array: | |
849 | */ | |
6f505b16 PZ |
850 | static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) |
851 | { | |
852 | struct sched_rt_entity *rt_se = &p->rt; | |
853 | ||
854 | if (wakeup) | |
855 | rt_se->timeout = 0; | |
856 | ||
ad2a3f13 | 857 | enqueue_rt_entity(rt_se); |
c09595f6 | 858 | |
917b627d GH |
859 | if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) |
860 | enqueue_pushable_task(rq, p); | |
861 | ||
c09595f6 | 862 | inc_cpu_load(rq, p->se.load.weight); |
6f505b16 PZ |
863 | } |
864 | ||
f02231e5 | 865 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) |
bb44e5d1 | 866 | { |
6f505b16 | 867 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 868 | |
f1e14ef6 | 869 | update_curr_rt(rq); |
ad2a3f13 | 870 | dequeue_rt_entity(rt_se); |
c09595f6 | 871 | |
917b627d GH |
872 | dequeue_pushable_task(rq, p); |
873 | ||
c09595f6 | 874 | dec_cpu_load(rq, p->se.load.weight); |
bb44e5d1 IM |
875 | } |
876 | ||
877 | /* | |
878 | * Put task to the end of the run list without the overhead of dequeue | |
879 | * followed by enqueue. | |
880 | */ | |
7ebefa8c DA |
881 | static void |
882 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 883 | { |
1cdad715 | 884 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
885 | struct rt_prio_array *array = &rt_rq->active; |
886 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
887 | ||
888 | if (head) | |
889 | list_move(&rt_se->run_list, queue); | |
890 | else | |
891 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 892 | } |
6f505b16 PZ |
893 | } |
894 | ||
7ebefa8c | 895 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 896 | { |
6f505b16 PZ |
897 | struct sched_rt_entity *rt_se = &p->rt; |
898 | struct rt_rq *rt_rq; | |
bb44e5d1 | 899 | |
6f505b16 PZ |
900 | for_each_sched_rt_entity(rt_se) { |
901 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 902 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 903 | } |
bb44e5d1 IM |
904 | } |
905 | ||
6f505b16 | 906 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 907 | { |
7ebefa8c | 908 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
909 | } |
910 | ||
e7693a36 | 911 | #ifdef CONFIG_SMP |
318e0893 GH |
912 | static int find_lowest_rq(struct task_struct *task); |
913 | ||
e7693a36 GH |
914 | static int select_task_rq_rt(struct task_struct *p, int sync) |
915 | { | |
318e0893 GH |
916 | struct rq *rq = task_rq(p); |
917 | ||
918 | /* | |
e1f47d89 SR |
919 | * If the current task is an RT task, then |
920 | * try to see if we can wake this RT task up on another | |
921 | * runqueue. Otherwise simply start this RT task | |
922 | * on its current runqueue. | |
923 | * | |
924 | * We want to avoid overloading runqueues. Even if | |
925 | * the RT task is of higher priority than the current RT task. | |
926 | * RT tasks behave differently than other tasks. If | |
927 | * one gets preempted, we try to push it off to another queue. | |
928 | * So trying to keep a preempting RT task on the same | |
929 | * cache hot CPU will force the running RT task to | |
930 | * a cold CPU. So we waste all the cache for the lower | |
931 | * RT task in hopes of saving some of a RT task | |
932 | * that is just being woken and probably will have | |
933 | * cold cache anyway. | |
318e0893 | 934 | */ |
17b3279b | 935 | if (unlikely(rt_task(rq->curr)) && |
6f505b16 | 936 | (p->rt.nr_cpus_allowed > 1)) { |
318e0893 GH |
937 | int cpu = find_lowest_rq(p); |
938 | ||
939 | return (cpu == -1) ? task_cpu(p) : cpu; | |
940 | } | |
941 | ||
942 | /* | |
943 | * Otherwise, just let it ride on the affined RQ and the | |
944 | * post-schedule router will push the preempted task away | |
945 | */ | |
e7693a36 GH |
946 | return task_cpu(p); |
947 | } | |
7ebefa8c DA |
948 | |
949 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
950 | { | |
24600ce8 | 951 | cpumask_var_t mask; |
7ebefa8c DA |
952 | |
953 | if (rq->curr->rt.nr_cpus_allowed == 1) | |
954 | return; | |
955 | ||
24600ce8 | 956 | if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) |
7ebefa8c DA |
957 | return; |
958 | ||
24600ce8 RR |
959 | if (p->rt.nr_cpus_allowed != 1 |
960 | && cpupri_find(&rq->rd->cpupri, p, mask)) | |
961 | goto free; | |
962 | ||
963 | if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask)) | |
964 | goto free; | |
7ebefa8c DA |
965 | |
966 | /* | |
967 | * There appears to be other cpus that can accept | |
968 | * current and none to run 'p', so lets reschedule | |
969 | * to try and push current away: | |
970 | */ | |
971 | requeue_task_rt(rq, p, 1); | |
972 | resched_task(rq->curr); | |
24600ce8 RR |
973 | free: |
974 | free_cpumask_var(mask); | |
7ebefa8c DA |
975 | } |
976 | ||
e7693a36 GH |
977 | #endif /* CONFIG_SMP */ |
978 | ||
bb44e5d1 IM |
979 | /* |
980 | * Preempt the current task with a newly woken task if needed: | |
981 | */ | |
15afe09b | 982 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) |
bb44e5d1 | 983 | { |
45c01e82 | 984 | if (p->prio < rq->curr->prio) { |
bb44e5d1 | 985 | resched_task(rq->curr); |
45c01e82 GH |
986 | return; |
987 | } | |
988 | ||
989 | #ifdef CONFIG_SMP | |
990 | /* | |
991 | * If: | |
992 | * | |
993 | * - the newly woken task is of equal priority to the current task | |
994 | * - the newly woken task is non-migratable while current is migratable | |
995 | * - current will be preempted on the next reschedule | |
996 | * | |
997 | * we should check to see if current can readily move to a different | |
998 | * cpu. If so, we will reschedule to allow the push logic to try | |
999 | * to move current somewhere else, making room for our non-migratable | |
1000 | * task. | |
1001 | */ | |
7ebefa8c DA |
1002 | if (p->prio == rq->curr->prio && !need_resched()) |
1003 | check_preempt_equal_prio(rq, p); | |
45c01e82 | 1004 | #endif |
bb44e5d1 IM |
1005 | } |
1006 | ||
6f505b16 PZ |
1007 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
1008 | struct rt_rq *rt_rq) | |
bb44e5d1 | 1009 | { |
6f505b16 PZ |
1010 | struct rt_prio_array *array = &rt_rq->active; |
1011 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1012 | struct list_head *queue; |
1013 | int idx; | |
1014 | ||
1015 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1016 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1017 | |
1018 | queue = array->queue + idx; | |
6f505b16 | 1019 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1020 | |
6f505b16 PZ |
1021 | return next; |
1022 | } | |
bb44e5d1 | 1023 | |
917b627d | 1024 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1025 | { |
1026 | struct sched_rt_entity *rt_se; | |
1027 | struct task_struct *p; | |
1028 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1029 | |
6f505b16 PZ |
1030 | rt_rq = &rq->rt; |
1031 | ||
1032 | if (unlikely(!rt_rq->rt_nr_running)) | |
1033 | return NULL; | |
1034 | ||
23b0fdfc | 1035 | if (rt_rq_throttled(rt_rq)) |
6f505b16 PZ |
1036 | return NULL; |
1037 | ||
1038 | do { | |
1039 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
326587b8 | 1040 | BUG_ON(!rt_se); |
6f505b16 PZ |
1041 | rt_rq = group_rt_rq(rt_se); |
1042 | } while (rt_rq); | |
1043 | ||
1044 | p = rt_task_of(rt_se); | |
1045 | p->se.exec_start = rq->clock; | |
917b627d GH |
1046 | |
1047 | return p; | |
1048 | } | |
1049 | ||
1050 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
1051 | { | |
1052 | struct task_struct *p = _pick_next_task_rt(rq); | |
1053 | ||
1054 | /* The running task is never eligible for pushing */ | |
1055 | if (p) | |
1056 | dequeue_pushable_task(rq, p); | |
1057 | ||
6f505b16 | 1058 | return p; |
bb44e5d1 IM |
1059 | } |
1060 | ||
31ee529c | 1061 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1062 | { |
f1e14ef6 | 1063 | update_curr_rt(rq); |
bb44e5d1 | 1064 | p->se.exec_start = 0; |
917b627d GH |
1065 | |
1066 | /* | |
1067 | * The previous task needs to be made eligible for pushing | |
1068 | * if it is still active | |
1069 | */ | |
1070 | if (p->se.on_rq && p->rt.nr_cpus_allowed > 1) | |
1071 | enqueue_pushable_task(rq, p); | |
bb44e5d1 IM |
1072 | } |
1073 | ||
681f3e68 | 1074 | #ifdef CONFIG_SMP |
6f505b16 | 1075 | |
e8fa1362 SR |
1076 | /* Only try algorithms three times */ |
1077 | #define RT_MAX_TRIES 3 | |
1078 | ||
e8fa1362 SR |
1079 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); |
1080 | ||
f65eda4f SR |
1081 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1082 | { | |
1083 | if (!task_running(rq, p) && | |
96f874e2 | 1084 | (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) && |
6f505b16 | 1085 | (p->rt.nr_cpus_allowed > 1)) |
f65eda4f SR |
1086 | return 1; |
1087 | return 0; | |
1088 | } | |
1089 | ||
e8fa1362 | 1090 | /* Return the second highest RT task, NULL otherwise */ |
79064fbf | 1091 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) |
e8fa1362 | 1092 | { |
6f505b16 PZ |
1093 | struct task_struct *next = NULL; |
1094 | struct sched_rt_entity *rt_se; | |
1095 | struct rt_prio_array *array; | |
1096 | struct rt_rq *rt_rq; | |
e8fa1362 SR |
1097 | int idx; |
1098 | ||
6f505b16 PZ |
1099 | for_each_leaf_rt_rq(rt_rq, rq) { |
1100 | array = &rt_rq->active; | |
1101 | idx = sched_find_first_bit(array->bitmap); | |
1102 | next_idx: | |
1103 | if (idx >= MAX_RT_PRIO) | |
1104 | continue; | |
1105 | if (next && next->prio < idx) | |
1106 | continue; | |
1107 | list_for_each_entry(rt_se, array->queue + idx, run_list) { | |
1108 | struct task_struct *p = rt_task_of(rt_se); | |
1109 | if (pick_rt_task(rq, p, cpu)) { | |
1110 | next = p; | |
1111 | break; | |
1112 | } | |
1113 | } | |
1114 | if (!next) { | |
1115 | idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); | |
1116 | goto next_idx; | |
1117 | } | |
f65eda4f SR |
1118 | } |
1119 | ||
e8fa1362 SR |
1120 | return next; |
1121 | } | |
1122 | ||
0e3900e6 | 1123 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1124 | |
d38b223c MT |
1125 | static inline int pick_optimal_cpu(int this_cpu, |
1126 | const struct cpumask *mask) | |
6e1254d2 GH |
1127 | { |
1128 | int first; | |
1129 | ||
1130 | /* "this_cpu" is cheaper to preempt than a remote processor */ | |
d38b223c | 1131 | if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask)) |
6e1254d2 GH |
1132 | return this_cpu; |
1133 | ||
3d398703 RR |
1134 | first = cpumask_first(mask); |
1135 | if (first < nr_cpu_ids) | |
6e1254d2 GH |
1136 | return first; |
1137 | ||
1138 | return -1; | |
1139 | } | |
1140 | ||
1141 | static int find_lowest_rq(struct task_struct *task) | |
1142 | { | |
1143 | struct sched_domain *sd; | |
96f874e2 | 1144 | struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); |
6e1254d2 GH |
1145 | int this_cpu = smp_processor_id(); |
1146 | int cpu = task_cpu(task); | |
d38b223c | 1147 | cpumask_var_t domain_mask; |
06f90dbd | 1148 | |
6e0534f2 GH |
1149 | if (task->rt.nr_cpus_allowed == 1) |
1150 | return -1; /* No other targets possible */ | |
6e1254d2 | 1151 | |
6e0534f2 GH |
1152 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
1153 | return -1; /* No targets found */ | |
6e1254d2 | 1154 | |
e761b772 MK |
1155 | /* |
1156 | * Only consider CPUs that are usable for migration. | |
1157 | * I guess we might want to change cpupri_find() to ignore those | |
1158 | * in the first place. | |
1159 | */ | |
96f874e2 | 1160 | cpumask_and(lowest_mask, lowest_mask, cpu_active_mask); |
e761b772 | 1161 | |
6e1254d2 GH |
1162 | /* |
1163 | * At this point we have built a mask of cpus representing the | |
1164 | * lowest priority tasks in the system. Now we want to elect | |
1165 | * the best one based on our affinity and topology. | |
1166 | * | |
1167 | * We prioritize the last cpu that the task executed on since | |
1168 | * it is most likely cache-hot in that location. | |
1169 | */ | |
96f874e2 | 1170 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1171 | return cpu; |
1172 | ||
1173 | /* | |
1174 | * Otherwise, we consult the sched_domains span maps to figure | |
1175 | * out which cpu is logically closest to our hot cache data. | |
1176 | */ | |
1177 | if (this_cpu == cpu) | |
1178 | this_cpu = -1; /* Skip this_cpu opt if the same */ | |
1179 | ||
d38b223c MT |
1180 | if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) { |
1181 | for_each_domain(cpu, sd) { | |
1182 | if (sd->flags & SD_WAKE_AFFINE) { | |
1183 | int best_cpu; | |
6e1254d2 | 1184 | |
d38b223c MT |
1185 | cpumask_and(domain_mask, |
1186 | sched_domain_span(sd), | |
1187 | lowest_mask); | |
6e1254d2 | 1188 | |
d38b223c MT |
1189 | best_cpu = pick_optimal_cpu(this_cpu, |
1190 | domain_mask); | |
1191 | ||
1192 | if (best_cpu != -1) { | |
1193 | free_cpumask_var(domain_mask); | |
1194 | return best_cpu; | |
1195 | } | |
1196 | } | |
6e1254d2 | 1197 | } |
d38b223c | 1198 | free_cpumask_var(domain_mask); |
6e1254d2 GH |
1199 | } |
1200 | ||
1201 | /* | |
1202 | * And finally, if there were no matches within the domains | |
1203 | * just give the caller *something* to work with from the compatible | |
1204 | * locations. | |
1205 | */ | |
1206 | return pick_optimal_cpu(this_cpu, lowest_mask); | |
07b4032c GH |
1207 | } |
1208 | ||
1209 | /* Will lock the rq it finds */ | |
4df64c0b | 1210 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1211 | { |
1212 | struct rq *lowest_rq = NULL; | |
07b4032c | 1213 | int tries; |
4df64c0b | 1214 | int cpu; |
e8fa1362 | 1215 | |
07b4032c GH |
1216 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1217 | cpu = find_lowest_rq(task); | |
1218 | ||
2de0b463 | 1219 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1220 | break; |
1221 | ||
07b4032c GH |
1222 | lowest_rq = cpu_rq(cpu); |
1223 | ||
e8fa1362 | 1224 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1225 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1226 | /* |
1227 | * We had to unlock the run queue. In | |
1228 | * the mean time, task could have | |
1229 | * migrated already or had its affinity changed. | |
1230 | * Also make sure that it wasn't scheduled on its rq. | |
1231 | */ | |
07b4032c | 1232 | if (unlikely(task_rq(task) != rq || |
96f874e2 RR |
1233 | !cpumask_test_cpu(lowest_rq->cpu, |
1234 | &task->cpus_allowed) || | |
07b4032c | 1235 | task_running(rq, task) || |
e8fa1362 | 1236 | !task->se.on_rq)) { |
4df64c0b | 1237 | |
e8fa1362 SR |
1238 | spin_unlock(&lowest_rq->lock); |
1239 | lowest_rq = NULL; | |
1240 | break; | |
1241 | } | |
1242 | } | |
1243 | ||
1244 | /* If this rq is still suitable use it. */ | |
e864c499 | 1245 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1246 | break; |
1247 | ||
1248 | /* try again */ | |
1b12bbc7 | 1249 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1250 | lowest_rq = NULL; |
1251 | } | |
1252 | ||
1253 | return lowest_rq; | |
1254 | } | |
1255 | ||
917b627d GH |
1256 | static inline int has_pushable_tasks(struct rq *rq) |
1257 | { | |
1258 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
1259 | } | |
1260 | ||
1261 | static struct task_struct *pick_next_pushable_task(struct rq *rq) | |
1262 | { | |
1263 | struct task_struct *p; | |
1264 | ||
1265 | if (!has_pushable_tasks(rq)) | |
1266 | return NULL; | |
1267 | ||
1268 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1269 | struct task_struct, pushable_tasks); | |
1270 | ||
1271 | BUG_ON(rq->cpu != task_cpu(p)); | |
1272 | BUG_ON(task_current(rq, p)); | |
1273 | BUG_ON(p->rt.nr_cpus_allowed <= 1); | |
1274 | ||
1275 | BUG_ON(!p->se.on_rq); | |
1276 | BUG_ON(!rt_task(p)); | |
1277 | ||
1278 | return p; | |
1279 | } | |
1280 | ||
e8fa1362 SR |
1281 | /* |
1282 | * If the current CPU has more than one RT task, see if the non | |
1283 | * running task can migrate over to a CPU that is running a task | |
1284 | * of lesser priority. | |
1285 | */ | |
697f0a48 | 1286 | static int push_rt_task(struct rq *rq) |
e8fa1362 SR |
1287 | { |
1288 | struct task_struct *next_task; | |
1289 | struct rq *lowest_rq; | |
e8fa1362 | 1290 | |
a22d7fc1 GH |
1291 | if (!rq->rt.overloaded) |
1292 | return 0; | |
1293 | ||
917b627d | 1294 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
1295 | if (!next_task) |
1296 | return 0; | |
1297 | ||
1298 | retry: | |
697f0a48 | 1299 | if (unlikely(next_task == rq->curr)) { |
f65eda4f | 1300 | WARN_ON(1); |
e8fa1362 | 1301 | return 0; |
f65eda4f | 1302 | } |
e8fa1362 SR |
1303 | |
1304 | /* | |
1305 | * It's possible that the next_task slipped in of | |
1306 | * higher priority than current. If that's the case | |
1307 | * just reschedule current. | |
1308 | */ | |
697f0a48 GH |
1309 | if (unlikely(next_task->prio < rq->curr->prio)) { |
1310 | resched_task(rq->curr); | |
e8fa1362 SR |
1311 | return 0; |
1312 | } | |
1313 | ||
697f0a48 | 1314 | /* We might release rq lock */ |
e8fa1362 SR |
1315 | get_task_struct(next_task); |
1316 | ||
1317 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 1318 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
1319 | if (!lowest_rq) { |
1320 | struct task_struct *task; | |
1321 | /* | |
697f0a48 | 1322 | * find lock_lowest_rq releases rq->lock |
1563513d GH |
1323 | * so it is possible that next_task has migrated. |
1324 | * | |
1325 | * We need to make sure that the task is still on the same | |
1326 | * run-queue and is also still the next task eligible for | |
1327 | * pushing. | |
e8fa1362 | 1328 | */ |
917b627d | 1329 | task = pick_next_pushable_task(rq); |
1563513d GH |
1330 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
1331 | /* | |
1332 | * If we get here, the task hasnt moved at all, but | |
1333 | * it has failed to push. We will not try again, | |
1334 | * since the other cpus will pull from us when they | |
1335 | * are ready. | |
1336 | */ | |
1337 | dequeue_pushable_task(rq, next_task); | |
1338 | goto out; | |
e8fa1362 | 1339 | } |
917b627d | 1340 | |
1563513d GH |
1341 | if (!task) |
1342 | /* No more tasks, just exit */ | |
1343 | goto out; | |
1344 | ||
917b627d | 1345 | /* |
1563513d | 1346 | * Something has shifted, try again. |
917b627d | 1347 | */ |
1563513d GH |
1348 | put_task_struct(next_task); |
1349 | next_task = task; | |
1350 | goto retry; | |
e8fa1362 SR |
1351 | } |
1352 | ||
697f0a48 | 1353 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
1354 | set_task_cpu(next_task, lowest_rq->cpu); |
1355 | activate_task(lowest_rq, next_task, 0); | |
1356 | ||
1357 | resched_task(lowest_rq->curr); | |
1358 | ||
1b12bbc7 | 1359 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 | 1360 | |
e8fa1362 SR |
1361 | out: |
1362 | put_task_struct(next_task); | |
1363 | ||
917b627d | 1364 | return 1; |
e8fa1362 SR |
1365 | } |
1366 | ||
e8fa1362 SR |
1367 | static void push_rt_tasks(struct rq *rq) |
1368 | { | |
1369 | /* push_rt_task will return true if it moved an RT */ | |
1370 | while (push_rt_task(rq)) | |
1371 | ; | |
1372 | } | |
1373 | ||
f65eda4f SR |
1374 | static int pull_rt_task(struct rq *this_rq) |
1375 | { | |
80bf3171 | 1376 | int this_cpu = this_rq->cpu, ret = 0, cpu; |
a8728944 | 1377 | struct task_struct *p; |
f65eda4f | 1378 | struct rq *src_rq; |
f65eda4f | 1379 | |
637f5085 | 1380 | if (likely(!rt_overloaded(this_rq))) |
f65eda4f SR |
1381 | return 0; |
1382 | ||
c6c4927b | 1383 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
1384 | if (this_cpu == cpu) |
1385 | continue; | |
1386 | ||
1387 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
1388 | |
1389 | /* | |
1390 | * Don't bother taking the src_rq->lock if the next highest | |
1391 | * task is known to be lower-priority than our current task. | |
1392 | * This may look racy, but if this value is about to go | |
1393 | * logically higher, the src_rq will push this task away. | |
1394 | * And if its going logically lower, we do not care | |
1395 | */ | |
1396 | if (src_rq->rt.highest_prio.next >= | |
1397 | this_rq->rt.highest_prio.curr) | |
1398 | continue; | |
1399 | ||
f65eda4f SR |
1400 | /* |
1401 | * We can potentially drop this_rq's lock in | |
1402 | * double_lock_balance, and another CPU could | |
a8728944 | 1403 | * alter this_rq |
f65eda4f | 1404 | */ |
a8728944 | 1405 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
1406 | |
1407 | /* | |
1408 | * Are there still pullable RT tasks? | |
1409 | */ | |
614ee1f6 MG |
1410 | if (src_rq->rt.rt_nr_running <= 1) |
1411 | goto skip; | |
f65eda4f | 1412 | |
f65eda4f SR |
1413 | p = pick_next_highest_task_rt(src_rq, this_cpu); |
1414 | ||
1415 | /* | |
1416 | * Do we have an RT task that preempts | |
1417 | * the to-be-scheduled task? | |
1418 | */ | |
a8728944 | 1419 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f SR |
1420 | WARN_ON(p == src_rq->curr); |
1421 | WARN_ON(!p->se.on_rq); | |
1422 | ||
1423 | /* | |
1424 | * There's a chance that p is higher in priority | |
1425 | * than what's currently running on its cpu. | |
1426 | * This is just that p is wakeing up and hasn't | |
1427 | * had a chance to schedule. We only pull | |
1428 | * p if it is lower in priority than the | |
a8728944 | 1429 | * current task on the run queue |
f65eda4f | 1430 | */ |
a8728944 | 1431 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 1432 | goto skip; |
f65eda4f SR |
1433 | |
1434 | ret = 1; | |
1435 | ||
1436 | deactivate_task(src_rq, p, 0); | |
1437 | set_task_cpu(p, this_cpu); | |
1438 | activate_task(this_rq, p, 0); | |
1439 | /* | |
1440 | * We continue with the search, just in | |
1441 | * case there's an even higher prio task | |
1442 | * in another runqueue. (low likelyhood | |
1443 | * but possible) | |
f65eda4f | 1444 | */ |
f65eda4f | 1445 | } |
614ee1f6 | 1446 | skip: |
1b12bbc7 | 1447 | double_unlock_balance(this_rq, src_rq); |
f65eda4f SR |
1448 | } |
1449 | ||
1450 | return ret; | |
1451 | } | |
1452 | ||
9a897c5a | 1453 | static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) |
f65eda4f SR |
1454 | { |
1455 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
e864c499 | 1456 | if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio) |
f65eda4f SR |
1457 | pull_rt_task(rq); |
1458 | } | |
1459 | ||
967fc046 GH |
1460 | /* |
1461 | * assumes rq->lock is held | |
1462 | */ | |
1463 | static int needs_post_schedule_rt(struct rq *rq) | |
1464 | { | |
917b627d | 1465 | return has_pushable_tasks(rq); |
967fc046 GH |
1466 | } |
1467 | ||
9a897c5a | 1468 | static void post_schedule_rt(struct rq *rq) |
e8fa1362 SR |
1469 | { |
1470 | /* | |
967fc046 GH |
1471 | * This is only called if needs_post_schedule_rt() indicates that |
1472 | * we need to push tasks away | |
e8fa1362 | 1473 | */ |
967fc046 GH |
1474 | spin_lock_irq(&rq->lock); |
1475 | push_rt_tasks(rq); | |
1476 | spin_unlock_irq(&rq->lock); | |
e8fa1362 SR |
1477 | } |
1478 | ||
8ae121ac GH |
1479 | /* |
1480 | * If we are not running and we are not going to reschedule soon, we should | |
1481 | * try to push tasks away now | |
1482 | */ | |
9a897c5a | 1483 | static void task_wake_up_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 1484 | { |
9a897c5a | 1485 | if (!task_running(rq, p) && |
8ae121ac | 1486 | !test_tsk_need_resched(rq->curr) && |
917b627d | 1487 | has_pushable_tasks(rq) && |
777c2f38 | 1488 | p->rt.nr_cpus_allowed > 1) |
4642dafd SR |
1489 | push_rt_tasks(rq); |
1490 | } | |
1491 | ||
43010659 | 1492 | static unsigned long |
bb44e5d1 | 1493 | load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, |
e1d1484f PW |
1494 | unsigned long max_load_move, |
1495 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1496 | int *all_pinned, int *this_best_prio) | |
bb44e5d1 | 1497 | { |
c7a1e46a SR |
1498 | /* don't touch RT tasks */ |
1499 | return 0; | |
e1d1484f PW |
1500 | } |
1501 | ||
1502 | static int | |
1503 | move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1504 | struct sched_domain *sd, enum cpu_idle_type idle) | |
1505 | { | |
c7a1e46a SR |
1506 | /* don't touch RT tasks */ |
1507 | return 0; | |
bb44e5d1 | 1508 | } |
deeeccd4 | 1509 | |
cd8ba7cd | 1510 | static void set_cpus_allowed_rt(struct task_struct *p, |
96f874e2 | 1511 | const struct cpumask *new_mask) |
73fe6aae | 1512 | { |
96f874e2 | 1513 | int weight = cpumask_weight(new_mask); |
73fe6aae GH |
1514 | |
1515 | BUG_ON(!rt_task(p)); | |
1516 | ||
1517 | /* | |
1518 | * Update the migration status of the RQ if we have an RT task | |
1519 | * which is running AND changing its weight value. | |
1520 | */ | |
6f505b16 | 1521 | if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) { |
73fe6aae GH |
1522 | struct rq *rq = task_rq(p); |
1523 | ||
917b627d GH |
1524 | if (!task_current(rq, p)) { |
1525 | /* | |
1526 | * Make sure we dequeue this task from the pushable list | |
1527 | * before going further. It will either remain off of | |
1528 | * the list because we are no longer pushable, or it | |
1529 | * will be requeued. | |
1530 | */ | |
1531 | if (p->rt.nr_cpus_allowed > 1) | |
1532 | dequeue_pushable_task(rq, p); | |
1533 | ||
1534 | /* | |
1535 | * Requeue if our weight is changing and still > 1 | |
1536 | */ | |
1537 | if (weight > 1) | |
1538 | enqueue_pushable_task(rq, p); | |
1539 | ||
1540 | } | |
1541 | ||
6f505b16 | 1542 | if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { |
73fe6aae | 1543 | rq->rt.rt_nr_migratory++; |
6f505b16 | 1544 | } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { |
73fe6aae GH |
1545 | BUG_ON(!rq->rt.rt_nr_migratory); |
1546 | rq->rt.rt_nr_migratory--; | |
1547 | } | |
1548 | ||
398a153b | 1549 | update_rt_migration(&rq->rt); |
73fe6aae GH |
1550 | } |
1551 | ||
96f874e2 | 1552 | cpumask_copy(&p->cpus_allowed, new_mask); |
6f505b16 | 1553 | p->rt.nr_cpus_allowed = weight; |
73fe6aae | 1554 | } |
deeeccd4 | 1555 | |
bdd7c81b | 1556 | /* Assumes rq->lock is held */ |
1f11eb6a | 1557 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
1558 | { |
1559 | if (rq->rt.overloaded) | |
1560 | rt_set_overload(rq); | |
6e0534f2 | 1561 | |
7def2be1 PZ |
1562 | __enable_runtime(rq); |
1563 | ||
e864c499 | 1564 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
1565 | } |
1566 | ||
1567 | /* Assumes rq->lock is held */ | |
1f11eb6a | 1568 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
1569 | { |
1570 | if (rq->rt.overloaded) | |
1571 | rt_clear_overload(rq); | |
6e0534f2 | 1572 | |
7def2be1 PZ |
1573 | __disable_runtime(rq); |
1574 | ||
6e0534f2 | 1575 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 1576 | } |
cb469845 SR |
1577 | |
1578 | /* | |
1579 | * When switch from the rt queue, we bring ourselves to a position | |
1580 | * that we might want to pull RT tasks from other runqueues. | |
1581 | */ | |
1582 | static void switched_from_rt(struct rq *rq, struct task_struct *p, | |
1583 | int running) | |
1584 | { | |
1585 | /* | |
1586 | * If there are other RT tasks then we will reschedule | |
1587 | * and the scheduling of the other RT tasks will handle | |
1588 | * the balancing. But if we are the last RT task | |
1589 | * we may need to handle the pulling of RT tasks | |
1590 | * now. | |
1591 | */ | |
1592 | if (!rq->rt.rt_nr_running) | |
1593 | pull_rt_task(rq); | |
1594 | } | |
3d8cbdf8 RR |
1595 | |
1596 | static inline void init_sched_rt_class(void) | |
1597 | { | |
1598 | unsigned int i; | |
1599 | ||
1600 | for_each_possible_cpu(i) | |
6ca09dfc MT |
1601 | alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
1602 | GFP_KERNEL, cpu_to_node(i)); | |
3d8cbdf8 | 1603 | } |
cb469845 SR |
1604 | #endif /* CONFIG_SMP */ |
1605 | ||
1606 | /* | |
1607 | * When switching a task to RT, we may overload the runqueue | |
1608 | * with RT tasks. In this case we try to push them off to | |
1609 | * other runqueues. | |
1610 | */ | |
1611 | static void switched_to_rt(struct rq *rq, struct task_struct *p, | |
1612 | int running) | |
1613 | { | |
1614 | int check_resched = 1; | |
1615 | ||
1616 | /* | |
1617 | * If we are already running, then there's nothing | |
1618 | * that needs to be done. But if we are not running | |
1619 | * we may need to preempt the current running task. | |
1620 | * If that current running task is also an RT task | |
1621 | * then see if we can move to another run queue. | |
1622 | */ | |
1623 | if (!running) { | |
1624 | #ifdef CONFIG_SMP | |
1625 | if (rq->rt.overloaded && push_rt_task(rq) && | |
1626 | /* Don't resched if we changed runqueues */ | |
1627 | rq != task_rq(p)) | |
1628 | check_resched = 0; | |
1629 | #endif /* CONFIG_SMP */ | |
1630 | if (check_resched && p->prio < rq->curr->prio) | |
1631 | resched_task(rq->curr); | |
1632 | } | |
1633 | } | |
1634 | ||
1635 | /* | |
1636 | * Priority of the task has changed. This may cause | |
1637 | * us to initiate a push or pull. | |
1638 | */ | |
1639 | static void prio_changed_rt(struct rq *rq, struct task_struct *p, | |
1640 | int oldprio, int running) | |
1641 | { | |
1642 | if (running) { | |
1643 | #ifdef CONFIG_SMP | |
1644 | /* | |
1645 | * If our priority decreases while running, we | |
1646 | * may need to pull tasks to this runqueue. | |
1647 | */ | |
1648 | if (oldprio < p->prio) | |
1649 | pull_rt_task(rq); | |
1650 | /* | |
1651 | * If there's a higher priority task waiting to run | |
6fa46fa5 SR |
1652 | * then reschedule. Note, the above pull_rt_task |
1653 | * can release the rq lock and p could migrate. | |
1654 | * Only reschedule if p is still on the same runqueue. | |
cb469845 | 1655 | */ |
e864c499 | 1656 | if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) |
cb469845 SR |
1657 | resched_task(p); |
1658 | #else | |
1659 | /* For UP simply resched on drop of prio */ | |
1660 | if (oldprio < p->prio) | |
1661 | resched_task(p); | |
e8fa1362 | 1662 | #endif /* CONFIG_SMP */ |
cb469845 SR |
1663 | } else { |
1664 | /* | |
1665 | * This task is not running, but if it is | |
1666 | * greater than the current running task | |
1667 | * then reschedule. | |
1668 | */ | |
1669 | if (p->prio < rq->curr->prio) | |
1670 | resched_task(rq->curr); | |
1671 | } | |
1672 | } | |
1673 | ||
78f2c7db PZ |
1674 | static void watchdog(struct rq *rq, struct task_struct *p) |
1675 | { | |
1676 | unsigned long soft, hard; | |
1677 | ||
1678 | if (!p->signal) | |
1679 | return; | |
1680 | ||
1681 | soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur; | |
1682 | hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max; | |
1683 | ||
1684 | if (soft != RLIM_INFINITY) { | |
1685 | unsigned long next; | |
1686 | ||
1687 | p->rt.timeout++; | |
1688 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); | |
5a52dd50 | 1689 | if (p->rt.timeout > next) |
f06febc9 | 1690 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
78f2c7db PZ |
1691 | } |
1692 | } | |
bb44e5d1 | 1693 | |
8f4d37ec | 1694 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 1695 | { |
67e2be02 PZ |
1696 | update_curr_rt(rq); |
1697 | ||
78f2c7db PZ |
1698 | watchdog(rq, p); |
1699 | ||
bb44e5d1 IM |
1700 | /* |
1701 | * RR tasks need a special form of timeslice management. | |
1702 | * FIFO tasks have no timeslices. | |
1703 | */ | |
1704 | if (p->policy != SCHED_RR) | |
1705 | return; | |
1706 | ||
fa717060 | 1707 | if (--p->rt.time_slice) |
bb44e5d1 IM |
1708 | return; |
1709 | ||
fa717060 | 1710 | p->rt.time_slice = DEF_TIMESLICE; |
bb44e5d1 | 1711 | |
98fbc798 DA |
1712 | /* |
1713 | * Requeue to the end of queue if we are not the only element | |
1714 | * on the queue: | |
1715 | */ | |
fa717060 | 1716 | if (p->rt.run_list.prev != p->rt.run_list.next) { |
7ebefa8c | 1717 | requeue_task_rt(rq, p, 0); |
98fbc798 DA |
1718 | set_tsk_need_resched(p); |
1719 | } | |
bb44e5d1 IM |
1720 | } |
1721 | ||
83b699ed SV |
1722 | static void set_curr_task_rt(struct rq *rq) |
1723 | { | |
1724 | struct task_struct *p = rq->curr; | |
1725 | ||
1726 | p->se.exec_start = rq->clock; | |
917b627d GH |
1727 | |
1728 | /* The running task is never eligible for pushing */ | |
1729 | dequeue_pushable_task(rq, p); | |
83b699ed SV |
1730 | } |
1731 | ||
2abdad0a | 1732 | static const struct sched_class rt_sched_class = { |
5522d5d5 | 1733 | .next = &fair_sched_class, |
bb44e5d1 IM |
1734 | .enqueue_task = enqueue_task_rt, |
1735 | .dequeue_task = dequeue_task_rt, | |
1736 | .yield_task = yield_task_rt, | |
1737 | ||
1738 | .check_preempt_curr = check_preempt_curr_rt, | |
1739 | ||
1740 | .pick_next_task = pick_next_task_rt, | |
1741 | .put_prev_task = put_prev_task_rt, | |
1742 | ||
681f3e68 | 1743 | #ifdef CONFIG_SMP |
4ce72a2c LZ |
1744 | .select_task_rq = select_task_rq_rt, |
1745 | ||
bb44e5d1 | 1746 | .load_balance = load_balance_rt, |
e1d1484f | 1747 | .move_one_task = move_one_task_rt, |
73fe6aae | 1748 | .set_cpus_allowed = set_cpus_allowed_rt, |
1f11eb6a GH |
1749 | .rq_online = rq_online_rt, |
1750 | .rq_offline = rq_offline_rt, | |
9a897c5a | 1751 | .pre_schedule = pre_schedule_rt, |
967fc046 | 1752 | .needs_post_schedule = needs_post_schedule_rt, |
9a897c5a SR |
1753 | .post_schedule = post_schedule_rt, |
1754 | .task_wake_up = task_wake_up_rt, | |
cb469845 | 1755 | .switched_from = switched_from_rt, |
681f3e68 | 1756 | #endif |
bb44e5d1 | 1757 | |
83b699ed | 1758 | .set_curr_task = set_curr_task_rt, |
bb44e5d1 | 1759 | .task_tick = task_tick_rt, |
cb469845 SR |
1760 | |
1761 | .prio_changed = prio_changed_rt, | |
1762 | .switched_to = switched_to_rt, | |
bb44e5d1 | 1763 | }; |
ada18de2 PZ |
1764 | |
1765 | #ifdef CONFIG_SCHED_DEBUG | |
1766 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
1767 | ||
1768 | static void print_rt_stats(struct seq_file *m, int cpu) | |
1769 | { | |
1770 | struct rt_rq *rt_rq; | |
1771 | ||
1772 | rcu_read_lock(); | |
1773 | for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu)) | |
1774 | print_rt_rq(m, cpu, rt_rq); | |
1775 | rcu_read_unlock(); | |
1776 | } | |
55e12e5e | 1777 | #endif /* CONFIG_SCHED_DEBUG */ |
0e3900e6 | 1778 |