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Commit | Line | Data |
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bb44e5d1 IM |
1 | /* |
2 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR | |
3 | * policies) | |
4 | */ | |
5 | ||
4fd29176 | 6 | #ifdef CONFIG_SMP |
84de4274 | 7 | |
637f5085 | 8 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 9 | { |
637f5085 | 10 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 11 | } |
84de4274 | 12 | |
4fd29176 SR |
13 | static inline void rt_set_overload(struct rq *rq) |
14 | { | |
1f11eb6a GH |
15 | if (!rq->online) |
16 | return; | |
17 | ||
c6c4927b | 18 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
19 | /* |
20 | * Make sure the mask is visible before we set | |
21 | * the overload count. That is checked to determine | |
22 | * if we should look at the mask. It would be a shame | |
23 | * if we looked at the mask, but the mask was not | |
24 | * updated yet. | |
25 | */ | |
26 | wmb(); | |
637f5085 | 27 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 28 | } |
84de4274 | 29 | |
4fd29176 SR |
30 | static inline void rt_clear_overload(struct rq *rq) |
31 | { | |
1f11eb6a GH |
32 | if (!rq->online) |
33 | return; | |
34 | ||
4fd29176 | 35 | /* the order here really doesn't matter */ |
637f5085 | 36 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 37 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 38 | } |
73fe6aae GH |
39 | |
40 | static void update_rt_migration(struct rq *rq) | |
41 | { | |
637f5085 | 42 | if (rq->rt.rt_nr_migratory && (rq->rt.rt_nr_running > 1)) { |
cdc8eb98 GH |
43 | if (!rq->rt.overloaded) { |
44 | rt_set_overload(rq); | |
45 | rq->rt.overloaded = 1; | |
46 | } | |
47 | } else if (rq->rt.overloaded) { | |
73fe6aae | 48 | rt_clear_overload(rq); |
637f5085 GH |
49 | rq->rt.overloaded = 0; |
50 | } | |
73fe6aae | 51 | } |
917b627d GH |
52 | |
53 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) | |
54 | { | |
55 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
56 | plist_node_init(&p->pushable_tasks, p->prio); | |
57 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
58 | } | |
59 | ||
60 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
61 | { | |
62 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
63 | } | |
64 | ||
65 | #else | |
66 | ||
b07430ac GH |
67 | static inline |
68 | void enqueue_pushable_task(struct rq *rq, struct task_struct *p) {} | |
69 | static inline | |
70 | void dequeue_pushable_task(struct rq *rq, struct task_struct *p) {} | |
917b627d | 71 | |
4fd29176 SR |
72 | #endif /* CONFIG_SMP */ |
73 | ||
6f505b16 | 74 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
fa85ae24 | 75 | { |
6f505b16 PZ |
76 | return container_of(rt_se, struct task_struct, rt); |
77 | } | |
78 | ||
79 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) | |
80 | { | |
81 | return !list_empty(&rt_se->run_list); | |
82 | } | |
83 | ||
052f1dc7 | 84 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 85 | |
9f0c1e56 | 86 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
87 | { |
88 | if (!rt_rq->tg) | |
9f0c1e56 | 89 | return RUNTIME_INF; |
6f505b16 | 90 | |
ac086bc2 PZ |
91 | return rt_rq->rt_runtime; |
92 | } | |
93 | ||
94 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
95 | { | |
96 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
97 | } |
98 | ||
99 | #define for_each_leaf_rt_rq(rt_rq, rq) \ | |
80f40ee4 | 100 | list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) |
6f505b16 PZ |
101 | |
102 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) | |
103 | { | |
104 | return rt_rq->rq; | |
105 | } | |
106 | ||
107 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
108 | { | |
109 | return rt_se->rt_rq; | |
110 | } | |
111 | ||
112 | #define for_each_sched_rt_entity(rt_se) \ | |
113 | for (; rt_se; rt_se = rt_se->parent) | |
114 | ||
115 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
116 | { | |
117 | return rt_se->my_q; | |
118 | } | |
119 | ||
120 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se); | |
121 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se); | |
122 | ||
9f0c1e56 | 123 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 124 | { |
f6121f4f | 125 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
6f505b16 PZ |
126 | struct sched_rt_entity *rt_se = rt_rq->rt_se; |
127 | ||
f6121f4f DF |
128 | if (rt_rq->rt_nr_running) { |
129 | if (rt_se && !on_rt_rq(rt_se)) | |
130 | enqueue_rt_entity(rt_se); | |
e864c499 | 131 | if (rt_rq->highest_prio.curr < curr->prio) |
1020387f | 132 | resched_task(curr); |
6f505b16 PZ |
133 | } |
134 | } | |
135 | ||
9f0c1e56 | 136 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
137 | { |
138 | struct sched_rt_entity *rt_se = rt_rq->rt_se; | |
139 | ||
140 | if (rt_se && on_rt_rq(rt_se)) | |
141 | dequeue_rt_entity(rt_se); | |
142 | } | |
143 | ||
23b0fdfc PZ |
144 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
145 | { | |
146 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
147 | } | |
148 | ||
149 | static int rt_se_boosted(struct sched_rt_entity *rt_se) | |
150 | { | |
151 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
152 | struct task_struct *p; | |
153 | ||
154 | if (rt_rq) | |
155 | return !!rt_rq->rt_nr_boosted; | |
156 | ||
157 | p = rt_task_of(rt_se); | |
158 | return p->prio != p->normal_prio; | |
159 | } | |
160 | ||
d0b27fa7 | 161 | #ifdef CONFIG_SMP |
c6c4927b | 162 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 PZ |
163 | { |
164 | return cpu_rq(smp_processor_id())->rd->span; | |
165 | } | |
6f505b16 | 166 | #else |
c6c4927b | 167 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 168 | { |
c6c4927b | 169 | return cpu_online_mask; |
d0b27fa7 PZ |
170 | } |
171 | #endif | |
6f505b16 | 172 | |
d0b27fa7 PZ |
173 | static inline |
174 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 175 | { |
d0b27fa7 PZ |
176 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
177 | } | |
9f0c1e56 | 178 | |
ac086bc2 PZ |
179 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
180 | { | |
181 | return &rt_rq->tg->rt_bandwidth; | |
182 | } | |
183 | ||
55e12e5e | 184 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
185 | |
186 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
187 | { | |
ac086bc2 PZ |
188 | return rt_rq->rt_runtime; |
189 | } | |
190 | ||
191 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
192 | { | |
193 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
194 | } |
195 | ||
196 | #define for_each_leaf_rt_rq(rt_rq, rq) \ | |
197 | for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
198 | ||
199 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) | |
200 | { | |
201 | return container_of(rt_rq, struct rq, rt); | |
202 | } | |
203 | ||
204 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
205 | { | |
206 | struct task_struct *p = rt_task_of(rt_se); | |
207 | struct rq *rq = task_rq(p); | |
208 | ||
209 | return &rq->rt; | |
210 | } | |
211 | ||
212 | #define for_each_sched_rt_entity(rt_se) \ | |
213 | for (; rt_se; rt_se = NULL) | |
214 | ||
215 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
216 | { | |
217 | return NULL; | |
218 | } | |
219 | ||
9f0c1e56 | 220 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 221 | { |
f3ade837 JB |
222 | if (rt_rq->rt_nr_running) |
223 | resched_task(rq_of_rt_rq(rt_rq)->curr); | |
6f505b16 PZ |
224 | } |
225 | ||
9f0c1e56 | 226 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
227 | { |
228 | } | |
229 | ||
23b0fdfc PZ |
230 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
231 | { | |
232 | return rt_rq->rt_throttled; | |
233 | } | |
d0b27fa7 | 234 | |
c6c4927b | 235 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 236 | { |
c6c4927b | 237 | return cpu_online_mask; |
d0b27fa7 PZ |
238 | } |
239 | ||
240 | static inline | |
241 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
242 | { | |
243 | return &cpu_rq(cpu)->rt; | |
244 | } | |
245 | ||
ac086bc2 PZ |
246 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
247 | { | |
248 | return &def_rt_bandwidth; | |
249 | } | |
250 | ||
55e12e5e | 251 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 252 | |
ac086bc2 | 253 | #ifdef CONFIG_SMP |
78333cdd PZ |
254 | /* |
255 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
256 | */ | |
b79f3833 | 257 | static int do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
258 | { |
259 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
260 | struct root_domain *rd = cpu_rq(smp_processor_id())->rd; | |
261 | int i, weight, more = 0; | |
262 | u64 rt_period; | |
263 | ||
c6c4927b | 264 | weight = cpumask_weight(rd->span); |
ac086bc2 PZ |
265 | |
266 | spin_lock(&rt_b->rt_runtime_lock); | |
267 | rt_period = ktime_to_ns(rt_b->rt_period); | |
c6c4927b | 268 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
269 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
270 | s64 diff; | |
271 | ||
272 | if (iter == rt_rq) | |
273 | continue; | |
274 | ||
275 | spin_lock(&iter->rt_runtime_lock); | |
78333cdd PZ |
276 | /* |
277 | * Either all rqs have inf runtime and there's nothing to steal | |
278 | * or __disable_runtime() below sets a specific rq to inf to | |
279 | * indicate its been disabled and disalow stealing. | |
280 | */ | |
7def2be1 PZ |
281 | if (iter->rt_runtime == RUNTIME_INF) |
282 | goto next; | |
283 | ||
78333cdd PZ |
284 | /* |
285 | * From runqueues with spare time, take 1/n part of their | |
286 | * spare time, but no more than our period. | |
287 | */ | |
ac086bc2 PZ |
288 | diff = iter->rt_runtime - iter->rt_time; |
289 | if (diff > 0) { | |
58838cf3 | 290 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
291 | if (rt_rq->rt_runtime + diff > rt_period) |
292 | diff = rt_period - rt_rq->rt_runtime; | |
293 | iter->rt_runtime -= diff; | |
294 | rt_rq->rt_runtime += diff; | |
295 | more = 1; | |
296 | if (rt_rq->rt_runtime == rt_period) { | |
297 | spin_unlock(&iter->rt_runtime_lock); | |
298 | break; | |
299 | } | |
300 | } | |
7def2be1 | 301 | next: |
ac086bc2 PZ |
302 | spin_unlock(&iter->rt_runtime_lock); |
303 | } | |
304 | spin_unlock(&rt_b->rt_runtime_lock); | |
305 | ||
306 | return more; | |
307 | } | |
7def2be1 | 308 | |
78333cdd PZ |
309 | /* |
310 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
311 | */ | |
7def2be1 PZ |
312 | static void __disable_runtime(struct rq *rq) |
313 | { | |
314 | struct root_domain *rd = rq->rd; | |
315 | struct rt_rq *rt_rq; | |
316 | ||
317 | if (unlikely(!scheduler_running)) | |
318 | return; | |
319 | ||
320 | for_each_leaf_rt_rq(rt_rq, rq) { | |
321 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
322 | s64 want; | |
323 | int i; | |
324 | ||
325 | spin_lock(&rt_b->rt_runtime_lock); | |
326 | spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
327 | /* |
328 | * Either we're all inf and nobody needs to borrow, or we're | |
329 | * already disabled and thus have nothing to do, or we have | |
330 | * exactly the right amount of runtime to take out. | |
331 | */ | |
7def2be1 PZ |
332 | if (rt_rq->rt_runtime == RUNTIME_INF || |
333 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
334 | goto balanced; | |
335 | spin_unlock(&rt_rq->rt_runtime_lock); | |
336 | ||
78333cdd PZ |
337 | /* |
338 | * Calculate the difference between what we started out with | |
339 | * and what we current have, that's the amount of runtime | |
340 | * we lend and now have to reclaim. | |
341 | */ | |
7def2be1 PZ |
342 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
343 | ||
78333cdd PZ |
344 | /* |
345 | * Greedy reclaim, take back as much as we can. | |
346 | */ | |
c6c4927b | 347 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
348 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
349 | s64 diff; | |
350 | ||
78333cdd PZ |
351 | /* |
352 | * Can't reclaim from ourselves or disabled runqueues. | |
353 | */ | |
f1679d08 | 354 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
355 | continue; |
356 | ||
357 | spin_lock(&iter->rt_runtime_lock); | |
358 | if (want > 0) { | |
359 | diff = min_t(s64, iter->rt_runtime, want); | |
360 | iter->rt_runtime -= diff; | |
361 | want -= diff; | |
362 | } else { | |
363 | iter->rt_runtime -= want; | |
364 | want -= want; | |
365 | } | |
366 | spin_unlock(&iter->rt_runtime_lock); | |
367 | ||
368 | if (!want) | |
369 | break; | |
370 | } | |
371 | ||
372 | spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
373 | /* |
374 | * We cannot be left wanting - that would mean some runtime | |
375 | * leaked out of the system. | |
376 | */ | |
7def2be1 PZ |
377 | BUG_ON(want); |
378 | balanced: | |
78333cdd PZ |
379 | /* |
380 | * Disable all the borrow logic by pretending we have inf | |
381 | * runtime - in which case borrowing doesn't make sense. | |
382 | */ | |
7def2be1 PZ |
383 | rt_rq->rt_runtime = RUNTIME_INF; |
384 | spin_unlock(&rt_rq->rt_runtime_lock); | |
385 | spin_unlock(&rt_b->rt_runtime_lock); | |
386 | } | |
387 | } | |
388 | ||
389 | static void disable_runtime(struct rq *rq) | |
390 | { | |
391 | unsigned long flags; | |
392 | ||
393 | spin_lock_irqsave(&rq->lock, flags); | |
394 | __disable_runtime(rq); | |
395 | spin_unlock_irqrestore(&rq->lock, flags); | |
396 | } | |
397 | ||
398 | static void __enable_runtime(struct rq *rq) | |
399 | { | |
7def2be1 PZ |
400 | struct rt_rq *rt_rq; |
401 | ||
402 | if (unlikely(!scheduler_running)) | |
403 | return; | |
404 | ||
78333cdd PZ |
405 | /* |
406 | * Reset each runqueue's bandwidth settings | |
407 | */ | |
7def2be1 PZ |
408 | for_each_leaf_rt_rq(rt_rq, rq) { |
409 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
410 | ||
411 | spin_lock(&rt_b->rt_runtime_lock); | |
412 | spin_lock(&rt_rq->rt_runtime_lock); | |
413 | rt_rq->rt_runtime = rt_b->rt_runtime; | |
414 | rt_rq->rt_time = 0; | |
baf25731 | 415 | rt_rq->rt_throttled = 0; |
7def2be1 PZ |
416 | spin_unlock(&rt_rq->rt_runtime_lock); |
417 | spin_unlock(&rt_b->rt_runtime_lock); | |
418 | } | |
419 | } | |
420 | ||
421 | static void enable_runtime(struct rq *rq) | |
422 | { | |
423 | unsigned long flags; | |
424 | ||
425 | spin_lock_irqsave(&rq->lock, flags); | |
426 | __enable_runtime(rq); | |
427 | spin_unlock_irqrestore(&rq->lock, flags); | |
428 | } | |
429 | ||
eff6549b PZ |
430 | static int balance_runtime(struct rt_rq *rt_rq) |
431 | { | |
432 | int more = 0; | |
433 | ||
434 | if (rt_rq->rt_time > rt_rq->rt_runtime) { | |
435 | spin_unlock(&rt_rq->rt_runtime_lock); | |
436 | more = do_balance_runtime(rt_rq); | |
437 | spin_lock(&rt_rq->rt_runtime_lock); | |
438 | } | |
439 | ||
440 | return more; | |
441 | } | |
55e12e5e | 442 | #else /* !CONFIG_SMP */ |
eff6549b PZ |
443 | static inline int balance_runtime(struct rt_rq *rt_rq) |
444 | { | |
445 | return 0; | |
446 | } | |
55e12e5e | 447 | #endif /* CONFIG_SMP */ |
ac086bc2 | 448 | |
eff6549b PZ |
449 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
450 | { | |
451 | int i, idle = 1; | |
c6c4927b | 452 | const struct cpumask *span; |
eff6549b | 453 | |
0b148fa0 | 454 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
eff6549b PZ |
455 | return 1; |
456 | ||
457 | span = sched_rt_period_mask(); | |
c6c4927b | 458 | for_each_cpu(i, span) { |
eff6549b PZ |
459 | int enqueue = 0; |
460 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
461 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
462 | ||
463 | spin_lock(&rq->lock); | |
464 | if (rt_rq->rt_time) { | |
465 | u64 runtime; | |
466 | ||
467 | spin_lock(&rt_rq->rt_runtime_lock); | |
468 | if (rt_rq->rt_throttled) | |
469 | balance_runtime(rt_rq); | |
470 | runtime = rt_rq->rt_runtime; | |
471 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
472 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
473 | rt_rq->rt_throttled = 0; | |
474 | enqueue = 1; | |
475 | } | |
476 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
477 | idle = 0; | |
478 | spin_unlock(&rt_rq->rt_runtime_lock); | |
6c3df255 PZ |
479 | } else if (rt_rq->rt_nr_running) |
480 | idle = 0; | |
eff6549b PZ |
481 | |
482 | if (enqueue) | |
483 | sched_rt_rq_enqueue(rt_rq); | |
484 | spin_unlock(&rq->lock); | |
485 | } | |
486 | ||
487 | return idle; | |
488 | } | |
ac086bc2 | 489 | |
6f505b16 PZ |
490 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
491 | { | |
052f1dc7 | 492 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
493 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
494 | ||
495 | if (rt_rq) | |
e864c499 | 496 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
497 | #endif |
498 | ||
499 | return rt_task_of(rt_se)->prio; | |
500 | } | |
501 | ||
9f0c1e56 | 502 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 503 | { |
9f0c1e56 | 504 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 505 | |
fa85ae24 | 506 | if (rt_rq->rt_throttled) |
23b0fdfc | 507 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 508 | |
ac086bc2 PZ |
509 | if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) |
510 | return 0; | |
511 | ||
b79f3833 PZ |
512 | balance_runtime(rt_rq); |
513 | runtime = sched_rt_runtime(rt_rq); | |
514 | if (runtime == RUNTIME_INF) | |
515 | return 0; | |
ac086bc2 | 516 | |
9f0c1e56 | 517 | if (rt_rq->rt_time > runtime) { |
6f505b16 | 518 | rt_rq->rt_throttled = 1; |
23b0fdfc | 519 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 520 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
521 | return 1; |
522 | } | |
fa85ae24 PZ |
523 | } |
524 | ||
525 | return 0; | |
526 | } | |
527 | ||
bb44e5d1 IM |
528 | /* |
529 | * Update the current task's runtime statistics. Skip current tasks that | |
530 | * are not in our scheduling class. | |
531 | */ | |
a9957449 | 532 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
533 | { |
534 | struct task_struct *curr = rq->curr; | |
6f505b16 PZ |
535 | struct sched_rt_entity *rt_se = &curr->rt; |
536 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
bb44e5d1 IM |
537 | u64 delta_exec; |
538 | ||
539 | if (!task_has_rt_policy(curr)) | |
540 | return; | |
541 | ||
d281918d | 542 | delta_exec = rq->clock - curr->se.exec_start; |
bb44e5d1 IM |
543 | if (unlikely((s64)delta_exec < 0)) |
544 | delta_exec = 0; | |
6cfb0d5d IM |
545 | |
546 | schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); | |
bb44e5d1 IM |
547 | |
548 | curr->se.sum_exec_runtime += delta_exec; | |
f06febc9 FM |
549 | account_group_exec_runtime(curr, delta_exec); |
550 | ||
d281918d | 551 | curr->se.exec_start = rq->clock; |
d842de87 | 552 | cpuacct_charge(curr, delta_exec); |
fa85ae24 | 553 | |
0b148fa0 PZ |
554 | if (!rt_bandwidth_enabled()) |
555 | return; | |
556 | ||
354d60c2 DG |
557 | for_each_sched_rt_entity(rt_se) { |
558 | rt_rq = rt_rq_of_se(rt_se); | |
559 | ||
cc2991cf | 560 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
e113a745 | 561 | spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf PZ |
562 | rt_rq->rt_time += delta_exec; |
563 | if (sched_rt_runtime_exceeded(rt_rq)) | |
564 | resched_task(curr); | |
e113a745 | 565 | spin_unlock(&rt_rq->rt_runtime_lock); |
cc2991cf | 566 | } |
354d60c2 | 567 | } |
bb44e5d1 IM |
568 | } |
569 | ||
e864c499 GH |
570 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
571 | ||
572 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu); | |
573 | ||
574 | static inline int next_prio(struct rq *rq) | |
575 | { | |
576 | struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu); | |
577 | ||
578 | if (next && rt_prio(next->prio)) | |
579 | return next->prio; | |
580 | else | |
581 | return MAX_RT_PRIO; | |
582 | } | |
583 | #endif | |
584 | ||
6f505b16 PZ |
585 | static inline |
586 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
63489e45 | 587 | { |
4d984277 | 588 | int prio = rt_se_prio(rt_se); |
577b4a58 | 589 | #ifdef CONFIG_SMP |
4d984277 | 590 | struct rq *rq = rq_of_rt_rq(rt_rq); |
577b4a58 | 591 | #endif |
1f11eb6a | 592 | |
4d984277 GH |
593 | WARN_ON(!rt_prio(prio)); |
594 | rt_rq->rt_nr_running++; | |
595 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED | |
e864c499 | 596 | if (prio < rt_rq->highest_prio.curr) { |
4d984277 | 597 | |
e864c499 GH |
598 | /* |
599 | * If the new task is higher in priority than anything on the | |
600 | * run-queue, we have a new high that must be published to | |
601 | * the world. We also know that the previous high becomes | |
602 | * our next-highest. | |
603 | */ | |
604 | rt_rq->highest_prio.next = rt_rq->highest_prio.curr; | |
605 | rt_rq->highest_prio.curr = prio; | |
1100ac91 | 606 | #ifdef CONFIG_SMP |
1f11eb6a | 607 | if (rq->online) |
4d984277 | 608 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); |
1100ac91 | 609 | #endif |
e864c499 GH |
610 | } else if (prio == rt_rq->highest_prio.curr) |
611 | /* | |
612 | * If the next task is equal in priority to the highest on | |
613 | * the run-queue, then we implicitly know that the next highest | |
614 | * task cannot be any lower than current | |
615 | */ | |
616 | rt_rq->highest_prio.next = prio; | |
617 | else if (prio < rt_rq->highest_prio.next) | |
618 | /* | |
619 | * Otherwise, we need to recompute next-highest | |
620 | */ | |
621 | rt_rq->highest_prio.next = next_prio(rq); | |
6f505b16 | 622 | #endif |
764a9d6f | 623 | #ifdef CONFIG_SMP |
4d984277 | 624 | if (rt_se->nr_cpus_allowed > 1) |
73fe6aae GH |
625 | rq->rt.rt_nr_migratory++; |
626 | ||
4d984277 | 627 | update_rt_migration(rq); |
6f505b16 | 628 | #endif |
052f1dc7 | 629 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
630 | if (rt_se_boosted(rt_se)) |
631 | rt_rq->rt_nr_boosted++; | |
d0b27fa7 PZ |
632 | |
633 | if (rt_rq->tg) | |
634 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
635 | #else | |
636 | start_rt_bandwidth(&def_rt_bandwidth); | |
23b0fdfc | 637 | #endif |
63489e45 SR |
638 | } |
639 | ||
6f505b16 PZ |
640 | static inline |
641 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
63489e45 | 642 | { |
6e0534f2 | 643 | #ifdef CONFIG_SMP |
4d984277 | 644 | struct rq *rq = rq_of_rt_rq(rt_rq); |
e864c499 | 645 | int highest_prio = rt_rq->highest_prio.curr; |
6e0534f2 GH |
646 | #endif |
647 | ||
6f505b16 PZ |
648 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); |
649 | WARN_ON(!rt_rq->rt_nr_running); | |
650 | rt_rq->rt_nr_running--; | |
052f1dc7 | 651 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
6f505b16 | 652 | if (rt_rq->rt_nr_running) { |
e864c499 | 653 | int prio = rt_se_prio(rt_se); |
764a9d6f | 654 | |
e864c499 | 655 | WARN_ON(prio < rt_rq->highest_prio.curr); |
764a9d6f | 656 | |
e864c499 GH |
657 | /* |
658 | * This may have been our highest or next-highest priority | |
659 | * task and therefore we may have some recomputation to do | |
660 | */ | |
661 | if (prio == rt_rq->highest_prio.curr) { | |
662 | struct rt_prio_array *array = &rt_rq->active; | |
663 | ||
664 | rt_rq->highest_prio.curr = | |
764a9d6f | 665 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
666 | } |
667 | ||
668 | if (prio <= rt_rq->highest_prio.next) | |
669 | rt_rq->highest_prio.next = next_prio(rq); | |
764a9d6f | 670 | } else |
e864c499 | 671 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
6f505b16 PZ |
672 | #endif |
673 | #ifdef CONFIG_SMP | |
4d984277 | 674 | if (rt_se->nr_cpus_allowed > 1) |
73fe6aae GH |
675 | rq->rt.rt_nr_migratory--; |
676 | ||
e864c499 GH |
677 | if (rq->online && rt_rq->highest_prio.curr != highest_prio) |
678 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
1f11eb6a | 679 | |
4d984277 | 680 | update_rt_migration(rq); |
764a9d6f | 681 | #endif /* CONFIG_SMP */ |
052f1dc7 | 682 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
683 | if (rt_se_boosted(rt_se)) |
684 | rt_rq->rt_nr_boosted--; | |
685 | ||
686 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
687 | #endif | |
63489e45 SR |
688 | } |
689 | ||
ad2a3f13 | 690 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) |
bb44e5d1 | 691 | { |
6f505b16 PZ |
692 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
693 | struct rt_prio_array *array = &rt_rq->active; | |
694 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 695 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 696 | |
ad2a3f13 PZ |
697 | /* |
698 | * Don't enqueue the group if its throttled, or when empty. | |
699 | * The latter is a consequence of the former when a child group | |
700 | * get throttled and the current group doesn't have any other | |
701 | * active members. | |
702 | */ | |
703 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) | |
6f505b16 | 704 | return; |
63489e45 | 705 | |
7ebefa8c | 706 | list_add_tail(&rt_se->run_list, queue); |
6f505b16 | 707 | __set_bit(rt_se_prio(rt_se), array->bitmap); |
78f2c7db | 708 | |
6f505b16 PZ |
709 | inc_rt_tasks(rt_se, rt_rq); |
710 | } | |
711 | ||
ad2a3f13 | 712 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) |
6f505b16 PZ |
713 | { |
714 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
715 | struct rt_prio_array *array = &rt_rq->active; | |
716 | ||
717 | list_del_init(&rt_se->run_list); | |
718 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
719 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
720 | ||
721 | dec_rt_tasks(rt_se, rt_rq); | |
722 | } | |
723 | ||
724 | /* | |
725 | * Because the prio of an upper entry depends on the lower | |
726 | * entries, we must remove entries top - down. | |
6f505b16 | 727 | */ |
ad2a3f13 | 728 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se) |
6f505b16 | 729 | { |
ad2a3f13 | 730 | struct sched_rt_entity *back = NULL; |
6f505b16 | 731 | |
58d6c2d7 PZ |
732 | for_each_sched_rt_entity(rt_se) { |
733 | rt_se->back = back; | |
734 | back = rt_se; | |
735 | } | |
736 | ||
737 | for (rt_se = back; rt_se; rt_se = rt_se->back) { | |
738 | if (on_rt_rq(rt_se)) | |
ad2a3f13 PZ |
739 | __dequeue_rt_entity(rt_se); |
740 | } | |
741 | } | |
742 | ||
743 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se) | |
744 | { | |
745 | dequeue_rt_stack(rt_se); | |
746 | for_each_sched_rt_entity(rt_se) | |
747 | __enqueue_rt_entity(rt_se); | |
748 | } | |
749 | ||
750 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se) | |
751 | { | |
752 | dequeue_rt_stack(rt_se); | |
753 | ||
754 | for_each_sched_rt_entity(rt_se) { | |
755 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
756 | ||
757 | if (rt_rq && rt_rq->rt_nr_running) | |
758 | __enqueue_rt_entity(rt_se); | |
58d6c2d7 | 759 | } |
bb44e5d1 IM |
760 | } |
761 | ||
762 | /* | |
763 | * Adding/removing a task to/from a priority array: | |
764 | */ | |
6f505b16 PZ |
765 | static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) |
766 | { | |
767 | struct sched_rt_entity *rt_se = &p->rt; | |
768 | ||
769 | if (wakeup) | |
770 | rt_se->timeout = 0; | |
771 | ||
ad2a3f13 | 772 | enqueue_rt_entity(rt_se); |
c09595f6 | 773 | |
917b627d GH |
774 | if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) |
775 | enqueue_pushable_task(rq, p); | |
776 | ||
c09595f6 | 777 | inc_cpu_load(rq, p->se.load.weight); |
6f505b16 PZ |
778 | } |
779 | ||
f02231e5 | 780 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) |
bb44e5d1 | 781 | { |
6f505b16 | 782 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 783 | |
f1e14ef6 | 784 | update_curr_rt(rq); |
ad2a3f13 | 785 | dequeue_rt_entity(rt_se); |
c09595f6 | 786 | |
917b627d GH |
787 | dequeue_pushable_task(rq, p); |
788 | ||
c09595f6 | 789 | dec_cpu_load(rq, p->se.load.weight); |
bb44e5d1 IM |
790 | } |
791 | ||
792 | /* | |
793 | * Put task to the end of the run list without the overhead of dequeue | |
794 | * followed by enqueue. | |
795 | */ | |
7ebefa8c DA |
796 | static void |
797 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 798 | { |
1cdad715 | 799 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
800 | struct rt_prio_array *array = &rt_rq->active; |
801 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
802 | ||
803 | if (head) | |
804 | list_move(&rt_se->run_list, queue); | |
805 | else | |
806 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 807 | } |
6f505b16 PZ |
808 | } |
809 | ||
7ebefa8c | 810 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 811 | { |
6f505b16 PZ |
812 | struct sched_rt_entity *rt_se = &p->rt; |
813 | struct rt_rq *rt_rq; | |
bb44e5d1 | 814 | |
6f505b16 PZ |
815 | for_each_sched_rt_entity(rt_se) { |
816 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 817 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 818 | } |
bb44e5d1 IM |
819 | } |
820 | ||
6f505b16 | 821 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 822 | { |
7ebefa8c | 823 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
824 | } |
825 | ||
e7693a36 | 826 | #ifdef CONFIG_SMP |
318e0893 GH |
827 | static int find_lowest_rq(struct task_struct *task); |
828 | ||
e7693a36 GH |
829 | static int select_task_rq_rt(struct task_struct *p, int sync) |
830 | { | |
318e0893 GH |
831 | struct rq *rq = task_rq(p); |
832 | ||
833 | /* | |
e1f47d89 SR |
834 | * If the current task is an RT task, then |
835 | * try to see if we can wake this RT task up on another | |
836 | * runqueue. Otherwise simply start this RT task | |
837 | * on its current runqueue. | |
838 | * | |
839 | * We want to avoid overloading runqueues. Even if | |
840 | * the RT task is of higher priority than the current RT task. | |
841 | * RT tasks behave differently than other tasks. If | |
842 | * one gets preempted, we try to push it off to another queue. | |
843 | * So trying to keep a preempting RT task on the same | |
844 | * cache hot CPU will force the running RT task to | |
845 | * a cold CPU. So we waste all the cache for the lower | |
846 | * RT task in hopes of saving some of a RT task | |
847 | * that is just being woken and probably will have | |
848 | * cold cache anyway. | |
318e0893 | 849 | */ |
17b3279b | 850 | if (unlikely(rt_task(rq->curr)) && |
6f505b16 | 851 | (p->rt.nr_cpus_allowed > 1)) { |
318e0893 GH |
852 | int cpu = find_lowest_rq(p); |
853 | ||
854 | return (cpu == -1) ? task_cpu(p) : cpu; | |
855 | } | |
856 | ||
857 | /* | |
858 | * Otherwise, just let it ride on the affined RQ and the | |
859 | * post-schedule router will push the preempted task away | |
860 | */ | |
e7693a36 GH |
861 | return task_cpu(p); |
862 | } | |
7ebefa8c DA |
863 | |
864 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
865 | { | |
24600ce8 | 866 | cpumask_var_t mask; |
7ebefa8c DA |
867 | |
868 | if (rq->curr->rt.nr_cpus_allowed == 1) | |
869 | return; | |
870 | ||
24600ce8 | 871 | if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) |
7ebefa8c DA |
872 | return; |
873 | ||
24600ce8 RR |
874 | if (p->rt.nr_cpus_allowed != 1 |
875 | && cpupri_find(&rq->rd->cpupri, p, mask)) | |
876 | goto free; | |
877 | ||
878 | if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask)) | |
879 | goto free; | |
7ebefa8c DA |
880 | |
881 | /* | |
882 | * There appears to be other cpus that can accept | |
883 | * current and none to run 'p', so lets reschedule | |
884 | * to try and push current away: | |
885 | */ | |
886 | requeue_task_rt(rq, p, 1); | |
887 | resched_task(rq->curr); | |
24600ce8 RR |
888 | free: |
889 | free_cpumask_var(mask); | |
7ebefa8c DA |
890 | } |
891 | ||
e7693a36 GH |
892 | #endif /* CONFIG_SMP */ |
893 | ||
bb44e5d1 IM |
894 | /* |
895 | * Preempt the current task with a newly woken task if needed: | |
896 | */ | |
15afe09b | 897 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) |
bb44e5d1 | 898 | { |
45c01e82 | 899 | if (p->prio < rq->curr->prio) { |
bb44e5d1 | 900 | resched_task(rq->curr); |
45c01e82 GH |
901 | return; |
902 | } | |
903 | ||
904 | #ifdef CONFIG_SMP | |
905 | /* | |
906 | * If: | |
907 | * | |
908 | * - the newly woken task is of equal priority to the current task | |
909 | * - the newly woken task is non-migratable while current is migratable | |
910 | * - current will be preempted on the next reschedule | |
911 | * | |
912 | * we should check to see if current can readily move to a different | |
913 | * cpu. If so, we will reschedule to allow the push logic to try | |
914 | * to move current somewhere else, making room for our non-migratable | |
915 | * task. | |
916 | */ | |
7ebefa8c DA |
917 | if (p->prio == rq->curr->prio && !need_resched()) |
918 | check_preempt_equal_prio(rq, p); | |
45c01e82 | 919 | #endif |
bb44e5d1 IM |
920 | } |
921 | ||
6f505b16 PZ |
922 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
923 | struct rt_rq *rt_rq) | |
bb44e5d1 | 924 | { |
6f505b16 PZ |
925 | struct rt_prio_array *array = &rt_rq->active; |
926 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
927 | struct list_head *queue; |
928 | int idx; | |
929 | ||
930 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 931 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
932 | |
933 | queue = array->queue + idx; | |
6f505b16 | 934 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 935 | |
6f505b16 PZ |
936 | return next; |
937 | } | |
bb44e5d1 | 938 | |
917b627d | 939 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
940 | { |
941 | struct sched_rt_entity *rt_se; | |
942 | struct task_struct *p; | |
943 | struct rt_rq *rt_rq; | |
bb44e5d1 | 944 | |
6f505b16 PZ |
945 | rt_rq = &rq->rt; |
946 | ||
947 | if (unlikely(!rt_rq->rt_nr_running)) | |
948 | return NULL; | |
949 | ||
23b0fdfc | 950 | if (rt_rq_throttled(rt_rq)) |
6f505b16 PZ |
951 | return NULL; |
952 | ||
953 | do { | |
954 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
326587b8 | 955 | BUG_ON(!rt_se); |
6f505b16 PZ |
956 | rt_rq = group_rt_rq(rt_se); |
957 | } while (rt_rq); | |
958 | ||
959 | p = rt_task_of(rt_se); | |
960 | p->se.exec_start = rq->clock; | |
917b627d GH |
961 | |
962 | return p; | |
963 | } | |
964 | ||
965 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
966 | { | |
967 | struct task_struct *p = _pick_next_task_rt(rq); | |
968 | ||
969 | /* The running task is never eligible for pushing */ | |
970 | if (p) | |
971 | dequeue_pushable_task(rq, p); | |
972 | ||
6f505b16 | 973 | return p; |
bb44e5d1 IM |
974 | } |
975 | ||
31ee529c | 976 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 977 | { |
f1e14ef6 | 978 | update_curr_rt(rq); |
bb44e5d1 | 979 | p->se.exec_start = 0; |
917b627d GH |
980 | |
981 | /* | |
982 | * The previous task needs to be made eligible for pushing | |
983 | * if it is still active | |
984 | */ | |
985 | if (p->se.on_rq && p->rt.nr_cpus_allowed > 1) | |
986 | enqueue_pushable_task(rq, p); | |
bb44e5d1 IM |
987 | } |
988 | ||
681f3e68 | 989 | #ifdef CONFIG_SMP |
6f505b16 | 990 | |
e8fa1362 SR |
991 | /* Only try algorithms three times */ |
992 | #define RT_MAX_TRIES 3 | |
993 | ||
e8fa1362 SR |
994 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); |
995 | ||
f65eda4f SR |
996 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
997 | { | |
998 | if (!task_running(rq, p) && | |
96f874e2 | 999 | (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) && |
6f505b16 | 1000 | (p->rt.nr_cpus_allowed > 1)) |
f65eda4f SR |
1001 | return 1; |
1002 | return 0; | |
1003 | } | |
1004 | ||
e8fa1362 | 1005 | /* Return the second highest RT task, NULL otherwise */ |
79064fbf | 1006 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) |
e8fa1362 | 1007 | { |
6f505b16 PZ |
1008 | struct task_struct *next = NULL; |
1009 | struct sched_rt_entity *rt_se; | |
1010 | struct rt_prio_array *array; | |
1011 | struct rt_rq *rt_rq; | |
e8fa1362 SR |
1012 | int idx; |
1013 | ||
6f505b16 PZ |
1014 | for_each_leaf_rt_rq(rt_rq, rq) { |
1015 | array = &rt_rq->active; | |
1016 | idx = sched_find_first_bit(array->bitmap); | |
1017 | next_idx: | |
1018 | if (idx >= MAX_RT_PRIO) | |
1019 | continue; | |
1020 | if (next && next->prio < idx) | |
1021 | continue; | |
1022 | list_for_each_entry(rt_se, array->queue + idx, run_list) { | |
1023 | struct task_struct *p = rt_task_of(rt_se); | |
1024 | if (pick_rt_task(rq, p, cpu)) { | |
1025 | next = p; | |
1026 | break; | |
1027 | } | |
1028 | } | |
1029 | if (!next) { | |
1030 | idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); | |
1031 | goto next_idx; | |
1032 | } | |
f65eda4f SR |
1033 | } |
1034 | ||
e8fa1362 SR |
1035 | return next; |
1036 | } | |
1037 | ||
0e3900e6 | 1038 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1039 | |
6e1254d2 GH |
1040 | static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask) |
1041 | { | |
1042 | int first; | |
1043 | ||
1044 | /* "this_cpu" is cheaper to preempt than a remote processor */ | |
1045 | if ((this_cpu != -1) && cpu_isset(this_cpu, *mask)) | |
1046 | return this_cpu; | |
1047 | ||
1048 | first = first_cpu(*mask); | |
1049 | if (first != NR_CPUS) | |
1050 | return first; | |
1051 | ||
1052 | return -1; | |
1053 | } | |
1054 | ||
1055 | static int find_lowest_rq(struct task_struct *task) | |
1056 | { | |
1057 | struct sched_domain *sd; | |
96f874e2 | 1058 | struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); |
6e1254d2 GH |
1059 | int this_cpu = smp_processor_id(); |
1060 | int cpu = task_cpu(task); | |
06f90dbd | 1061 | |
6e0534f2 GH |
1062 | if (task->rt.nr_cpus_allowed == 1) |
1063 | return -1; /* No other targets possible */ | |
6e1254d2 | 1064 | |
6e0534f2 GH |
1065 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
1066 | return -1; /* No targets found */ | |
6e1254d2 | 1067 | |
e761b772 MK |
1068 | /* |
1069 | * Only consider CPUs that are usable for migration. | |
1070 | * I guess we might want to change cpupri_find() to ignore those | |
1071 | * in the first place. | |
1072 | */ | |
96f874e2 | 1073 | cpumask_and(lowest_mask, lowest_mask, cpu_active_mask); |
e761b772 | 1074 | |
6e1254d2 GH |
1075 | /* |
1076 | * At this point we have built a mask of cpus representing the | |
1077 | * lowest priority tasks in the system. Now we want to elect | |
1078 | * the best one based on our affinity and topology. | |
1079 | * | |
1080 | * We prioritize the last cpu that the task executed on since | |
1081 | * it is most likely cache-hot in that location. | |
1082 | */ | |
96f874e2 | 1083 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1084 | return cpu; |
1085 | ||
1086 | /* | |
1087 | * Otherwise, we consult the sched_domains span maps to figure | |
1088 | * out which cpu is logically closest to our hot cache data. | |
1089 | */ | |
1090 | if (this_cpu == cpu) | |
1091 | this_cpu = -1; /* Skip this_cpu opt if the same */ | |
1092 | ||
1093 | for_each_domain(cpu, sd) { | |
1094 | if (sd->flags & SD_WAKE_AFFINE) { | |
1095 | cpumask_t domain_mask; | |
1096 | int best_cpu; | |
1097 | ||
758b2cdc RR |
1098 | cpumask_and(&domain_mask, sched_domain_span(sd), |
1099 | lowest_mask); | |
6e1254d2 GH |
1100 | |
1101 | best_cpu = pick_optimal_cpu(this_cpu, | |
1102 | &domain_mask); | |
1103 | if (best_cpu != -1) | |
1104 | return best_cpu; | |
1105 | } | |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * And finally, if there were no matches within the domains | |
1110 | * just give the caller *something* to work with from the compatible | |
1111 | * locations. | |
1112 | */ | |
1113 | return pick_optimal_cpu(this_cpu, lowest_mask); | |
07b4032c GH |
1114 | } |
1115 | ||
1116 | /* Will lock the rq it finds */ | |
4df64c0b | 1117 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1118 | { |
1119 | struct rq *lowest_rq = NULL; | |
07b4032c | 1120 | int tries; |
4df64c0b | 1121 | int cpu; |
e8fa1362 | 1122 | |
07b4032c GH |
1123 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1124 | cpu = find_lowest_rq(task); | |
1125 | ||
2de0b463 | 1126 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1127 | break; |
1128 | ||
07b4032c GH |
1129 | lowest_rq = cpu_rq(cpu); |
1130 | ||
e8fa1362 | 1131 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1132 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1133 | /* |
1134 | * We had to unlock the run queue. In | |
1135 | * the mean time, task could have | |
1136 | * migrated already or had its affinity changed. | |
1137 | * Also make sure that it wasn't scheduled on its rq. | |
1138 | */ | |
07b4032c | 1139 | if (unlikely(task_rq(task) != rq || |
96f874e2 RR |
1140 | !cpumask_test_cpu(lowest_rq->cpu, |
1141 | &task->cpus_allowed) || | |
07b4032c | 1142 | task_running(rq, task) || |
e8fa1362 | 1143 | !task->se.on_rq)) { |
4df64c0b | 1144 | |
e8fa1362 SR |
1145 | spin_unlock(&lowest_rq->lock); |
1146 | lowest_rq = NULL; | |
1147 | break; | |
1148 | } | |
1149 | } | |
1150 | ||
1151 | /* If this rq is still suitable use it. */ | |
e864c499 | 1152 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1153 | break; |
1154 | ||
1155 | /* try again */ | |
1b12bbc7 | 1156 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1157 | lowest_rq = NULL; |
1158 | } | |
1159 | ||
1160 | return lowest_rq; | |
1161 | } | |
1162 | ||
917b627d GH |
1163 | static inline int has_pushable_tasks(struct rq *rq) |
1164 | { | |
1165 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
1166 | } | |
1167 | ||
1168 | static struct task_struct *pick_next_pushable_task(struct rq *rq) | |
1169 | { | |
1170 | struct task_struct *p; | |
1171 | ||
1172 | if (!has_pushable_tasks(rq)) | |
1173 | return NULL; | |
1174 | ||
1175 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1176 | struct task_struct, pushable_tasks); | |
1177 | ||
1178 | BUG_ON(rq->cpu != task_cpu(p)); | |
1179 | BUG_ON(task_current(rq, p)); | |
1180 | BUG_ON(p->rt.nr_cpus_allowed <= 1); | |
1181 | ||
1182 | BUG_ON(!p->se.on_rq); | |
1183 | BUG_ON(!rt_task(p)); | |
1184 | ||
1185 | return p; | |
1186 | } | |
1187 | ||
e8fa1362 SR |
1188 | /* |
1189 | * If the current CPU has more than one RT task, see if the non | |
1190 | * running task can migrate over to a CPU that is running a task | |
1191 | * of lesser priority. | |
1192 | */ | |
697f0a48 | 1193 | static int push_rt_task(struct rq *rq) |
e8fa1362 SR |
1194 | { |
1195 | struct task_struct *next_task; | |
1196 | struct rq *lowest_rq; | |
e8fa1362 | 1197 | |
a22d7fc1 GH |
1198 | if (!rq->rt.overloaded) |
1199 | return 0; | |
1200 | ||
917b627d | 1201 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
1202 | if (!next_task) |
1203 | return 0; | |
1204 | ||
1205 | retry: | |
697f0a48 | 1206 | if (unlikely(next_task == rq->curr)) { |
f65eda4f | 1207 | WARN_ON(1); |
e8fa1362 | 1208 | return 0; |
f65eda4f | 1209 | } |
e8fa1362 SR |
1210 | |
1211 | /* | |
1212 | * It's possible that the next_task slipped in of | |
1213 | * higher priority than current. If that's the case | |
1214 | * just reschedule current. | |
1215 | */ | |
697f0a48 GH |
1216 | if (unlikely(next_task->prio < rq->curr->prio)) { |
1217 | resched_task(rq->curr); | |
e8fa1362 SR |
1218 | return 0; |
1219 | } | |
1220 | ||
697f0a48 | 1221 | /* We might release rq lock */ |
e8fa1362 SR |
1222 | get_task_struct(next_task); |
1223 | ||
1224 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 1225 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
1226 | if (!lowest_rq) { |
1227 | struct task_struct *task; | |
1228 | /* | |
697f0a48 | 1229 | * find lock_lowest_rq releases rq->lock |
1563513d GH |
1230 | * so it is possible that next_task has migrated. |
1231 | * | |
1232 | * We need to make sure that the task is still on the same | |
1233 | * run-queue and is also still the next task eligible for | |
1234 | * pushing. | |
e8fa1362 | 1235 | */ |
917b627d | 1236 | task = pick_next_pushable_task(rq); |
1563513d GH |
1237 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
1238 | /* | |
1239 | * If we get here, the task hasnt moved at all, but | |
1240 | * it has failed to push. We will not try again, | |
1241 | * since the other cpus will pull from us when they | |
1242 | * are ready. | |
1243 | */ | |
1244 | dequeue_pushable_task(rq, next_task); | |
1245 | goto out; | |
e8fa1362 | 1246 | } |
917b627d | 1247 | |
1563513d GH |
1248 | if (!task) |
1249 | /* No more tasks, just exit */ | |
1250 | goto out; | |
1251 | ||
917b627d | 1252 | /* |
1563513d | 1253 | * Something has shifted, try again. |
917b627d | 1254 | */ |
1563513d GH |
1255 | put_task_struct(next_task); |
1256 | next_task = task; | |
1257 | goto retry; | |
e8fa1362 SR |
1258 | } |
1259 | ||
697f0a48 | 1260 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
1261 | set_task_cpu(next_task, lowest_rq->cpu); |
1262 | activate_task(lowest_rq, next_task, 0); | |
1263 | ||
1264 | resched_task(lowest_rq->curr); | |
1265 | ||
1b12bbc7 | 1266 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 | 1267 | |
e8fa1362 SR |
1268 | out: |
1269 | put_task_struct(next_task); | |
1270 | ||
917b627d | 1271 | return 1; |
e8fa1362 SR |
1272 | } |
1273 | ||
e8fa1362 SR |
1274 | static void push_rt_tasks(struct rq *rq) |
1275 | { | |
1276 | /* push_rt_task will return true if it moved an RT */ | |
1277 | while (push_rt_task(rq)) | |
1278 | ; | |
1279 | } | |
1280 | ||
f65eda4f SR |
1281 | static int pull_rt_task(struct rq *this_rq) |
1282 | { | |
80bf3171 | 1283 | int this_cpu = this_rq->cpu, ret = 0, cpu; |
a8728944 | 1284 | struct task_struct *p; |
f65eda4f | 1285 | struct rq *src_rq; |
f65eda4f | 1286 | |
637f5085 | 1287 | if (likely(!rt_overloaded(this_rq))) |
f65eda4f SR |
1288 | return 0; |
1289 | ||
c6c4927b | 1290 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
1291 | if (this_cpu == cpu) |
1292 | continue; | |
1293 | ||
1294 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
1295 | |
1296 | /* | |
1297 | * Don't bother taking the src_rq->lock if the next highest | |
1298 | * task is known to be lower-priority than our current task. | |
1299 | * This may look racy, but if this value is about to go | |
1300 | * logically higher, the src_rq will push this task away. | |
1301 | * And if its going logically lower, we do not care | |
1302 | */ | |
1303 | if (src_rq->rt.highest_prio.next >= | |
1304 | this_rq->rt.highest_prio.curr) | |
1305 | continue; | |
1306 | ||
f65eda4f SR |
1307 | /* |
1308 | * We can potentially drop this_rq's lock in | |
1309 | * double_lock_balance, and another CPU could | |
a8728944 | 1310 | * alter this_rq |
f65eda4f | 1311 | */ |
a8728944 | 1312 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
1313 | |
1314 | /* | |
1315 | * Are there still pullable RT tasks? | |
1316 | */ | |
614ee1f6 MG |
1317 | if (src_rq->rt.rt_nr_running <= 1) |
1318 | goto skip; | |
f65eda4f | 1319 | |
f65eda4f SR |
1320 | p = pick_next_highest_task_rt(src_rq, this_cpu); |
1321 | ||
1322 | /* | |
1323 | * Do we have an RT task that preempts | |
1324 | * the to-be-scheduled task? | |
1325 | */ | |
a8728944 | 1326 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f SR |
1327 | WARN_ON(p == src_rq->curr); |
1328 | WARN_ON(!p->se.on_rq); | |
1329 | ||
1330 | /* | |
1331 | * There's a chance that p is higher in priority | |
1332 | * than what's currently running on its cpu. | |
1333 | * This is just that p is wakeing up and hasn't | |
1334 | * had a chance to schedule. We only pull | |
1335 | * p if it is lower in priority than the | |
a8728944 | 1336 | * current task on the run queue |
f65eda4f | 1337 | */ |
a8728944 | 1338 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 1339 | goto skip; |
f65eda4f SR |
1340 | |
1341 | ret = 1; | |
1342 | ||
1343 | deactivate_task(src_rq, p, 0); | |
1344 | set_task_cpu(p, this_cpu); | |
1345 | activate_task(this_rq, p, 0); | |
1346 | /* | |
1347 | * We continue with the search, just in | |
1348 | * case there's an even higher prio task | |
1349 | * in another runqueue. (low likelyhood | |
1350 | * but possible) | |
f65eda4f | 1351 | */ |
f65eda4f | 1352 | } |
614ee1f6 | 1353 | skip: |
1b12bbc7 | 1354 | double_unlock_balance(this_rq, src_rq); |
f65eda4f SR |
1355 | } |
1356 | ||
1357 | return ret; | |
1358 | } | |
1359 | ||
9a897c5a | 1360 | static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) |
f65eda4f SR |
1361 | { |
1362 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
e864c499 | 1363 | if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio) |
f65eda4f SR |
1364 | pull_rt_task(rq); |
1365 | } | |
1366 | ||
967fc046 GH |
1367 | /* |
1368 | * assumes rq->lock is held | |
1369 | */ | |
1370 | static int needs_post_schedule_rt(struct rq *rq) | |
1371 | { | |
917b627d | 1372 | return has_pushable_tasks(rq); |
967fc046 GH |
1373 | } |
1374 | ||
9a897c5a | 1375 | static void post_schedule_rt(struct rq *rq) |
e8fa1362 SR |
1376 | { |
1377 | /* | |
967fc046 GH |
1378 | * This is only called if needs_post_schedule_rt() indicates that |
1379 | * we need to push tasks away | |
e8fa1362 | 1380 | */ |
967fc046 GH |
1381 | spin_lock_irq(&rq->lock); |
1382 | push_rt_tasks(rq); | |
1383 | spin_unlock_irq(&rq->lock); | |
e8fa1362 SR |
1384 | } |
1385 | ||
8ae121ac GH |
1386 | /* |
1387 | * If we are not running and we are not going to reschedule soon, we should | |
1388 | * try to push tasks away now | |
1389 | */ | |
9a897c5a | 1390 | static void task_wake_up_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 1391 | { |
9a897c5a | 1392 | if (!task_running(rq, p) && |
8ae121ac | 1393 | !test_tsk_need_resched(rq->curr) && |
917b627d | 1394 | has_pushable_tasks(rq) && |
777c2f38 | 1395 | p->rt.nr_cpus_allowed > 1) |
4642dafd SR |
1396 | push_rt_tasks(rq); |
1397 | } | |
1398 | ||
43010659 | 1399 | static unsigned long |
bb44e5d1 | 1400 | load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, |
e1d1484f PW |
1401 | unsigned long max_load_move, |
1402 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1403 | int *all_pinned, int *this_best_prio) | |
bb44e5d1 | 1404 | { |
c7a1e46a SR |
1405 | /* don't touch RT tasks */ |
1406 | return 0; | |
e1d1484f PW |
1407 | } |
1408 | ||
1409 | static int | |
1410 | move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1411 | struct sched_domain *sd, enum cpu_idle_type idle) | |
1412 | { | |
c7a1e46a SR |
1413 | /* don't touch RT tasks */ |
1414 | return 0; | |
bb44e5d1 | 1415 | } |
deeeccd4 | 1416 | |
cd8ba7cd | 1417 | static void set_cpus_allowed_rt(struct task_struct *p, |
96f874e2 | 1418 | const struct cpumask *new_mask) |
73fe6aae | 1419 | { |
96f874e2 | 1420 | int weight = cpumask_weight(new_mask); |
73fe6aae GH |
1421 | |
1422 | BUG_ON(!rt_task(p)); | |
1423 | ||
1424 | /* | |
1425 | * Update the migration status of the RQ if we have an RT task | |
1426 | * which is running AND changing its weight value. | |
1427 | */ | |
6f505b16 | 1428 | if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) { |
73fe6aae GH |
1429 | struct rq *rq = task_rq(p); |
1430 | ||
917b627d GH |
1431 | if (!task_current(rq, p)) { |
1432 | /* | |
1433 | * Make sure we dequeue this task from the pushable list | |
1434 | * before going further. It will either remain off of | |
1435 | * the list because we are no longer pushable, or it | |
1436 | * will be requeued. | |
1437 | */ | |
1438 | if (p->rt.nr_cpus_allowed > 1) | |
1439 | dequeue_pushable_task(rq, p); | |
1440 | ||
1441 | /* | |
1442 | * Requeue if our weight is changing and still > 1 | |
1443 | */ | |
1444 | if (weight > 1) | |
1445 | enqueue_pushable_task(rq, p); | |
1446 | ||
1447 | } | |
1448 | ||
6f505b16 | 1449 | if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { |
73fe6aae | 1450 | rq->rt.rt_nr_migratory++; |
6f505b16 | 1451 | } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { |
73fe6aae GH |
1452 | BUG_ON(!rq->rt.rt_nr_migratory); |
1453 | rq->rt.rt_nr_migratory--; | |
1454 | } | |
1455 | ||
1456 | update_rt_migration(rq); | |
1457 | } | |
1458 | ||
96f874e2 | 1459 | cpumask_copy(&p->cpus_allowed, new_mask); |
6f505b16 | 1460 | p->rt.nr_cpus_allowed = weight; |
73fe6aae | 1461 | } |
deeeccd4 | 1462 | |
bdd7c81b | 1463 | /* Assumes rq->lock is held */ |
1f11eb6a | 1464 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
1465 | { |
1466 | if (rq->rt.overloaded) | |
1467 | rt_set_overload(rq); | |
6e0534f2 | 1468 | |
7def2be1 PZ |
1469 | __enable_runtime(rq); |
1470 | ||
e864c499 | 1471 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
1472 | } |
1473 | ||
1474 | /* Assumes rq->lock is held */ | |
1f11eb6a | 1475 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
1476 | { |
1477 | if (rq->rt.overloaded) | |
1478 | rt_clear_overload(rq); | |
6e0534f2 | 1479 | |
7def2be1 PZ |
1480 | __disable_runtime(rq); |
1481 | ||
6e0534f2 | 1482 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 1483 | } |
cb469845 SR |
1484 | |
1485 | /* | |
1486 | * When switch from the rt queue, we bring ourselves to a position | |
1487 | * that we might want to pull RT tasks from other runqueues. | |
1488 | */ | |
1489 | static void switched_from_rt(struct rq *rq, struct task_struct *p, | |
1490 | int running) | |
1491 | { | |
1492 | /* | |
1493 | * If there are other RT tasks then we will reschedule | |
1494 | * and the scheduling of the other RT tasks will handle | |
1495 | * the balancing. But if we are the last RT task | |
1496 | * we may need to handle the pulling of RT tasks | |
1497 | * now. | |
1498 | */ | |
1499 | if (!rq->rt.rt_nr_running) | |
1500 | pull_rt_task(rq); | |
1501 | } | |
3d8cbdf8 RR |
1502 | |
1503 | static inline void init_sched_rt_class(void) | |
1504 | { | |
1505 | unsigned int i; | |
1506 | ||
1507 | for_each_possible_cpu(i) | |
6ca09dfc MT |
1508 | alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
1509 | GFP_KERNEL, cpu_to_node(i)); | |
3d8cbdf8 | 1510 | } |
cb469845 SR |
1511 | #endif /* CONFIG_SMP */ |
1512 | ||
1513 | /* | |
1514 | * When switching a task to RT, we may overload the runqueue | |
1515 | * with RT tasks. In this case we try to push them off to | |
1516 | * other runqueues. | |
1517 | */ | |
1518 | static void switched_to_rt(struct rq *rq, struct task_struct *p, | |
1519 | int running) | |
1520 | { | |
1521 | int check_resched = 1; | |
1522 | ||
1523 | /* | |
1524 | * If we are already running, then there's nothing | |
1525 | * that needs to be done. But if we are not running | |
1526 | * we may need to preempt the current running task. | |
1527 | * If that current running task is also an RT task | |
1528 | * then see if we can move to another run queue. | |
1529 | */ | |
1530 | if (!running) { | |
1531 | #ifdef CONFIG_SMP | |
1532 | if (rq->rt.overloaded && push_rt_task(rq) && | |
1533 | /* Don't resched if we changed runqueues */ | |
1534 | rq != task_rq(p)) | |
1535 | check_resched = 0; | |
1536 | #endif /* CONFIG_SMP */ | |
1537 | if (check_resched && p->prio < rq->curr->prio) | |
1538 | resched_task(rq->curr); | |
1539 | } | |
1540 | } | |
1541 | ||
1542 | /* | |
1543 | * Priority of the task has changed. This may cause | |
1544 | * us to initiate a push or pull. | |
1545 | */ | |
1546 | static void prio_changed_rt(struct rq *rq, struct task_struct *p, | |
1547 | int oldprio, int running) | |
1548 | { | |
1549 | if (running) { | |
1550 | #ifdef CONFIG_SMP | |
1551 | /* | |
1552 | * If our priority decreases while running, we | |
1553 | * may need to pull tasks to this runqueue. | |
1554 | */ | |
1555 | if (oldprio < p->prio) | |
1556 | pull_rt_task(rq); | |
1557 | /* | |
1558 | * If there's a higher priority task waiting to run | |
6fa46fa5 SR |
1559 | * then reschedule. Note, the above pull_rt_task |
1560 | * can release the rq lock and p could migrate. | |
1561 | * Only reschedule if p is still on the same runqueue. | |
cb469845 | 1562 | */ |
e864c499 | 1563 | if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) |
cb469845 SR |
1564 | resched_task(p); |
1565 | #else | |
1566 | /* For UP simply resched on drop of prio */ | |
1567 | if (oldprio < p->prio) | |
1568 | resched_task(p); | |
e8fa1362 | 1569 | #endif /* CONFIG_SMP */ |
cb469845 SR |
1570 | } else { |
1571 | /* | |
1572 | * This task is not running, but if it is | |
1573 | * greater than the current running task | |
1574 | * then reschedule. | |
1575 | */ | |
1576 | if (p->prio < rq->curr->prio) | |
1577 | resched_task(rq->curr); | |
1578 | } | |
1579 | } | |
1580 | ||
78f2c7db PZ |
1581 | static void watchdog(struct rq *rq, struct task_struct *p) |
1582 | { | |
1583 | unsigned long soft, hard; | |
1584 | ||
1585 | if (!p->signal) | |
1586 | return; | |
1587 | ||
1588 | soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur; | |
1589 | hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max; | |
1590 | ||
1591 | if (soft != RLIM_INFINITY) { | |
1592 | unsigned long next; | |
1593 | ||
1594 | p->rt.timeout++; | |
1595 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); | |
5a52dd50 | 1596 | if (p->rt.timeout > next) |
f06febc9 | 1597 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
78f2c7db PZ |
1598 | } |
1599 | } | |
bb44e5d1 | 1600 | |
8f4d37ec | 1601 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 1602 | { |
67e2be02 PZ |
1603 | update_curr_rt(rq); |
1604 | ||
78f2c7db PZ |
1605 | watchdog(rq, p); |
1606 | ||
bb44e5d1 IM |
1607 | /* |
1608 | * RR tasks need a special form of timeslice management. | |
1609 | * FIFO tasks have no timeslices. | |
1610 | */ | |
1611 | if (p->policy != SCHED_RR) | |
1612 | return; | |
1613 | ||
fa717060 | 1614 | if (--p->rt.time_slice) |
bb44e5d1 IM |
1615 | return; |
1616 | ||
fa717060 | 1617 | p->rt.time_slice = DEF_TIMESLICE; |
bb44e5d1 | 1618 | |
98fbc798 DA |
1619 | /* |
1620 | * Requeue to the end of queue if we are not the only element | |
1621 | * on the queue: | |
1622 | */ | |
fa717060 | 1623 | if (p->rt.run_list.prev != p->rt.run_list.next) { |
7ebefa8c | 1624 | requeue_task_rt(rq, p, 0); |
98fbc798 DA |
1625 | set_tsk_need_resched(p); |
1626 | } | |
bb44e5d1 IM |
1627 | } |
1628 | ||
83b699ed SV |
1629 | static void set_curr_task_rt(struct rq *rq) |
1630 | { | |
1631 | struct task_struct *p = rq->curr; | |
1632 | ||
1633 | p->se.exec_start = rq->clock; | |
917b627d GH |
1634 | |
1635 | /* The running task is never eligible for pushing */ | |
1636 | dequeue_pushable_task(rq, p); | |
83b699ed SV |
1637 | } |
1638 | ||
2abdad0a | 1639 | static const struct sched_class rt_sched_class = { |
5522d5d5 | 1640 | .next = &fair_sched_class, |
bb44e5d1 IM |
1641 | .enqueue_task = enqueue_task_rt, |
1642 | .dequeue_task = dequeue_task_rt, | |
1643 | .yield_task = yield_task_rt, | |
1644 | ||
1645 | .check_preempt_curr = check_preempt_curr_rt, | |
1646 | ||
1647 | .pick_next_task = pick_next_task_rt, | |
1648 | .put_prev_task = put_prev_task_rt, | |
1649 | ||
681f3e68 | 1650 | #ifdef CONFIG_SMP |
4ce72a2c LZ |
1651 | .select_task_rq = select_task_rq_rt, |
1652 | ||
bb44e5d1 | 1653 | .load_balance = load_balance_rt, |
e1d1484f | 1654 | .move_one_task = move_one_task_rt, |
73fe6aae | 1655 | .set_cpus_allowed = set_cpus_allowed_rt, |
1f11eb6a GH |
1656 | .rq_online = rq_online_rt, |
1657 | .rq_offline = rq_offline_rt, | |
9a897c5a | 1658 | .pre_schedule = pre_schedule_rt, |
967fc046 | 1659 | .needs_post_schedule = needs_post_schedule_rt, |
9a897c5a SR |
1660 | .post_schedule = post_schedule_rt, |
1661 | .task_wake_up = task_wake_up_rt, | |
cb469845 | 1662 | .switched_from = switched_from_rt, |
681f3e68 | 1663 | #endif |
bb44e5d1 | 1664 | |
83b699ed | 1665 | .set_curr_task = set_curr_task_rt, |
bb44e5d1 | 1666 | .task_tick = task_tick_rt, |
cb469845 SR |
1667 | |
1668 | .prio_changed = prio_changed_rt, | |
1669 | .switched_to = switched_to_rt, | |
bb44e5d1 | 1670 | }; |
ada18de2 PZ |
1671 | |
1672 | #ifdef CONFIG_SCHED_DEBUG | |
1673 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
1674 | ||
1675 | static void print_rt_stats(struct seq_file *m, int cpu) | |
1676 | { | |
1677 | struct rt_rq *rt_rq; | |
1678 | ||
1679 | rcu_read_lock(); | |
1680 | for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu)) | |
1681 | print_rt_rq(m, cpu, rt_rq); | |
1682 | rcu_read_unlock(); | |
1683 | } | |
55e12e5e | 1684 | #endif /* CONFIG_SCHED_DEBUG */ |
0e3900e6 | 1685 |