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