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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 | ||
029632fb PZ |
6 | #include "sched.h" |
7 | ||
8 | #include <linux/slab.h> | |
9 | ||
10 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
11 | ||
12 | struct rt_bandwidth def_rt_bandwidth; | |
13 | ||
14 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
15 | { | |
16 | struct rt_bandwidth *rt_b = | |
17 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
18 | ktime_t now; | |
19 | int overrun; | |
20 | int idle = 0; | |
21 | ||
22 | for (;;) { | |
23 | now = hrtimer_cb_get_time(timer); | |
24 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
25 | ||
26 | if (!overrun) | |
27 | break; | |
28 | ||
29 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
30 | } | |
31 | ||
32 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
33 | } | |
34 | ||
35 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
36 | { | |
37 | rt_b->rt_period = ns_to_ktime(period); | |
38 | rt_b->rt_runtime = runtime; | |
39 | ||
40 | raw_spin_lock_init(&rt_b->rt_runtime_lock); | |
41 | ||
42 | hrtimer_init(&rt_b->rt_period_timer, | |
43 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
44 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
45 | } | |
46 | ||
47 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
48 | { | |
49 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) | |
50 | return; | |
51 | ||
52 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
53 | return; | |
54 | ||
55 | raw_spin_lock(&rt_b->rt_runtime_lock); | |
56 | start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period); | |
57 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
58 | } | |
59 | ||
60 | void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) | |
61 | { | |
62 | struct rt_prio_array *array; | |
63 | int i; | |
64 | ||
65 | array = &rt_rq->active; | |
66 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
67 | INIT_LIST_HEAD(array->queue + i); | |
68 | __clear_bit(i, array->bitmap); | |
69 | } | |
70 | /* delimiter for bitsearch: */ | |
71 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
72 | ||
73 | #if defined CONFIG_SMP | |
74 | rt_rq->highest_prio.curr = MAX_RT_PRIO; | |
75 | rt_rq->highest_prio.next = MAX_RT_PRIO; | |
76 | rt_rq->rt_nr_migratory = 0; | |
77 | rt_rq->overloaded = 0; | |
78 | plist_head_init(&rt_rq->pushable_tasks); | |
79 | #endif | |
80 | ||
81 | rt_rq->rt_time = 0; | |
82 | rt_rq->rt_throttled = 0; | |
83 | rt_rq->rt_runtime = 0; | |
84 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); | |
85 | } | |
86 | ||
8f48894f | 87 | #ifdef CONFIG_RT_GROUP_SCHED |
029632fb PZ |
88 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) |
89 | { | |
90 | hrtimer_cancel(&rt_b->rt_period_timer); | |
91 | } | |
8f48894f PZ |
92 | |
93 | #define rt_entity_is_task(rt_se) (!(rt_se)->my_q) | |
94 | ||
398a153b GH |
95 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
96 | { | |
8f48894f PZ |
97 | #ifdef CONFIG_SCHED_DEBUG |
98 | WARN_ON_ONCE(!rt_entity_is_task(rt_se)); | |
99 | #endif | |
398a153b GH |
100 | return container_of(rt_se, struct task_struct, rt); |
101 | } | |
102 | ||
398a153b GH |
103 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
104 | { | |
105 | return rt_rq->rq; | |
106 | } | |
107 | ||
108 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
109 | { | |
110 | return rt_se->rt_rq; | |
111 | } | |
112 | ||
029632fb PZ |
113 | void free_rt_sched_group(struct task_group *tg) |
114 | { | |
115 | int i; | |
116 | ||
117 | if (tg->rt_se) | |
118 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
119 | ||
120 | for_each_possible_cpu(i) { | |
121 | if (tg->rt_rq) | |
122 | kfree(tg->rt_rq[i]); | |
123 | if (tg->rt_se) | |
124 | kfree(tg->rt_se[i]); | |
125 | } | |
126 | ||
127 | kfree(tg->rt_rq); | |
128 | kfree(tg->rt_se); | |
129 | } | |
130 | ||
131 | void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, | |
132 | struct sched_rt_entity *rt_se, int cpu, | |
133 | struct sched_rt_entity *parent) | |
134 | { | |
135 | struct rq *rq = cpu_rq(cpu); | |
136 | ||
137 | rt_rq->highest_prio.curr = MAX_RT_PRIO; | |
138 | rt_rq->rt_nr_boosted = 0; | |
139 | rt_rq->rq = rq; | |
140 | rt_rq->tg = tg; | |
141 | ||
142 | tg->rt_rq[cpu] = rt_rq; | |
143 | tg->rt_se[cpu] = rt_se; | |
144 | ||
145 | if (!rt_se) | |
146 | return; | |
147 | ||
148 | if (!parent) | |
149 | rt_se->rt_rq = &rq->rt; | |
150 | else | |
151 | rt_se->rt_rq = parent->my_q; | |
152 | ||
153 | rt_se->my_q = rt_rq; | |
154 | rt_se->parent = parent; | |
155 | INIT_LIST_HEAD(&rt_se->run_list); | |
156 | } | |
157 | ||
158 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
159 | { | |
160 | struct rt_rq *rt_rq; | |
161 | struct sched_rt_entity *rt_se; | |
162 | int i; | |
163 | ||
164 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); | |
165 | if (!tg->rt_rq) | |
166 | goto err; | |
167 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); | |
168 | if (!tg->rt_se) | |
169 | goto err; | |
170 | ||
171 | init_rt_bandwidth(&tg->rt_bandwidth, | |
172 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
173 | ||
174 | for_each_possible_cpu(i) { | |
175 | rt_rq = kzalloc_node(sizeof(struct rt_rq), | |
176 | GFP_KERNEL, cpu_to_node(i)); | |
177 | if (!rt_rq) | |
178 | goto err; | |
179 | ||
180 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), | |
181 | GFP_KERNEL, cpu_to_node(i)); | |
182 | if (!rt_se) | |
183 | goto err_free_rq; | |
184 | ||
185 | init_rt_rq(rt_rq, cpu_rq(i)); | |
186 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; | |
187 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); | |
188 | } | |
189 | ||
190 | return 1; | |
191 | ||
192 | err_free_rq: | |
193 | kfree(rt_rq); | |
194 | err: | |
195 | return 0; | |
196 | } | |
197 | ||
398a153b GH |
198 | #else /* CONFIG_RT_GROUP_SCHED */ |
199 | ||
a1ba4d8b PZ |
200 | #define rt_entity_is_task(rt_se) (1) |
201 | ||
8f48894f PZ |
202 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
203 | { | |
204 | return container_of(rt_se, struct task_struct, rt); | |
205 | } | |
206 | ||
398a153b GH |
207 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
208 | { | |
209 | return container_of(rt_rq, struct rq, rt); | |
210 | } | |
211 | ||
212 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) | |
213 | { | |
214 | struct task_struct *p = rt_task_of(rt_se); | |
215 | struct rq *rq = task_rq(p); | |
216 | ||
217 | return &rq->rt; | |
218 | } | |
219 | ||
029632fb PZ |
220 | void free_rt_sched_group(struct task_group *tg) { } |
221 | ||
222 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
223 | { | |
224 | return 1; | |
225 | } | |
398a153b GH |
226 | #endif /* CONFIG_RT_GROUP_SCHED */ |
227 | ||
4fd29176 | 228 | #ifdef CONFIG_SMP |
84de4274 | 229 | |
637f5085 | 230 | static inline int rt_overloaded(struct rq *rq) |
4fd29176 | 231 | { |
637f5085 | 232 | return atomic_read(&rq->rd->rto_count); |
4fd29176 | 233 | } |
84de4274 | 234 | |
4fd29176 SR |
235 | static inline void rt_set_overload(struct rq *rq) |
236 | { | |
1f11eb6a GH |
237 | if (!rq->online) |
238 | return; | |
239 | ||
c6c4927b | 240 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 SR |
241 | /* |
242 | * Make sure the mask is visible before we set | |
243 | * the overload count. That is checked to determine | |
244 | * if we should look at the mask. It would be a shame | |
245 | * if we looked at the mask, but the mask was not | |
246 | * updated yet. | |
247 | */ | |
248 | wmb(); | |
637f5085 | 249 | atomic_inc(&rq->rd->rto_count); |
4fd29176 | 250 | } |
84de4274 | 251 | |
4fd29176 SR |
252 | static inline void rt_clear_overload(struct rq *rq) |
253 | { | |
1f11eb6a GH |
254 | if (!rq->online) |
255 | return; | |
256 | ||
4fd29176 | 257 | /* the order here really doesn't matter */ |
637f5085 | 258 | atomic_dec(&rq->rd->rto_count); |
c6c4927b | 259 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
4fd29176 | 260 | } |
73fe6aae | 261 | |
398a153b | 262 | static void update_rt_migration(struct rt_rq *rt_rq) |
73fe6aae | 263 | { |
a1ba4d8b | 264 | if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) { |
398a153b GH |
265 | if (!rt_rq->overloaded) { |
266 | rt_set_overload(rq_of_rt_rq(rt_rq)); | |
267 | rt_rq->overloaded = 1; | |
cdc8eb98 | 268 | } |
398a153b GH |
269 | } else if (rt_rq->overloaded) { |
270 | rt_clear_overload(rq_of_rt_rq(rt_rq)); | |
271 | rt_rq->overloaded = 0; | |
637f5085 | 272 | } |
73fe6aae | 273 | } |
4fd29176 | 274 | |
398a153b GH |
275 | static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
276 | { | |
29baa747 PZ |
277 | struct task_struct *p; |
278 | ||
a1ba4d8b PZ |
279 | if (!rt_entity_is_task(rt_se)) |
280 | return; | |
281 | ||
29baa747 | 282 | p = rt_task_of(rt_se); |
a1ba4d8b PZ |
283 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; |
284 | ||
285 | rt_rq->rt_nr_total++; | |
29baa747 | 286 | if (p->nr_cpus_allowed > 1) |
398a153b GH |
287 | rt_rq->rt_nr_migratory++; |
288 | ||
289 | update_rt_migration(rt_rq); | |
290 | } | |
291 | ||
292 | static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
293 | { | |
29baa747 PZ |
294 | struct task_struct *p; |
295 | ||
a1ba4d8b PZ |
296 | if (!rt_entity_is_task(rt_se)) |
297 | return; | |
298 | ||
29baa747 | 299 | p = rt_task_of(rt_se); |
a1ba4d8b PZ |
300 | rt_rq = &rq_of_rt_rq(rt_rq)->rt; |
301 | ||
302 | rt_rq->rt_nr_total--; | |
29baa747 | 303 | if (p->nr_cpus_allowed > 1) |
398a153b GH |
304 | rt_rq->rt_nr_migratory--; |
305 | ||
306 | update_rt_migration(rt_rq); | |
307 | } | |
308 | ||
5181f4a4 SR |
309 | static inline int has_pushable_tasks(struct rq *rq) |
310 | { | |
311 | return !plist_head_empty(&rq->rt.pushable_tasks); | |
312 | } | |
313 | ||
917b627d GH |
314 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
315 | { | |
316 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
317 | plist_node_init(&p->pushable_tasks, p->prio); | |
318 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
5181f4a4 SR |
319 | |
320 | /* Update the highest prio pushable task */ | |
321 | if (p->prio < rq->rt.highest_prio.next) | |
322 | rq->rt.highest_prio.next = p->prio; | |
917b627d GH |
323 | } |
324 | ||
325 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) | |
326 | { | |
327 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); | |
917b627d | 328 | |
5181f4a4 SR |
329 | /* Update the new highest prio pushable task */ |
330 | if (has_pushable_tasks(rq)) { | |
331 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
332 | struct task_struct, pushable_tasks); | |
333 | rq->rt.highest_prio.next = p->prio; | |
334 | } else | |
335 | rq->rt.highest_prio.next = MAX_RT_PRIO; | |
bcf08df3 IM |
336 | } |
337 | ||
917b627d GH |
338 | #else |
339 | ||
ceacc2c1 | 340 | static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
fa85ae24 | 341 | { |
6f505b16 PZ |
342 | } |
343 | ||
ceacc2c1 PZ |
344 | static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
345 | { | |
346 | } | |
347 | ||
b07430ac | 348 | static inline |
ceacc2c1 PZ |
349 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
350 | { | |
351 | } | |
352 | ||
398a153b | 353 | static inline |
ceacc2c1 PZ |
354 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
355 | { | |
356 | } | |
917b627d | 357 | |
4fd29176 SR |
358 | #endif /* CONFIG_SMP */ |
359 | ||
6f505b16 PZ |
360 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
361 | { | |
362 | return !list_empty(&rt_se->run_list); | |
363 | } | |
364 | ||
052f1dc7 | 365 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 366 | |
9f0c1e56 | 367 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
6f505b16 PZ |
368 | { |
369 | if (!rt_rq->tg) | |
9f0c1e56 | 370 | return RUNTIME_INF; |
6f505b16 | 371 | |
ac086bc2 PZ |
372 | return rt_rq->rt_runtime; |
373 | } | |
374 | ||
375 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
376 | { | |
377 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); | |
6f505b16 PZ |
378 | } |
379 | ||
ec514c48 CX |
380 | typedef struct task_group *rt_rq_iter_t; |
381 | ||
1c09ab0d YZ |
382 | static inline struct task_group *next_task_group(struct task_group *tg) |
383 | { | |
384 | do { | |
385 | tg = list_entry_rcu(tg->list.next, | |
386 | typeof(struct task_group), list); | |
387 | } while (&tg->list != &task_groups && task_group_is_autogroup(tg)); | |
388 | ||
389 | if (&tg->list == &task_groups) | |
390 | tg = NULL; | |
391 | ||
392 | return tg; | |
393 | } | |
394 | ||
395 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
396 | for (iter = container_of(&task_groups, typeof(*iter), list); \ | |
397 | (iter = next_task_group(iter)) && \ | |
398 | (rt_rq = iter->rt_rq[cpu_of(rq)]);) | |
ec514c48 | 399 | |
3d4b47b4 PZ |
400 | static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) |
401 | { | |
402 | list_add_rcu(&rt_rq->leaf_rt_rq_list, | |
403 | &rq_of_rt_rq(rt_rq)->leaf_rt_rq_list); | |
404 | } | |
405 | ||
406 | static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq) | |
407 | { | |
408 | list_del_rcu(&rt_rq->leaf_rt_rq_list); | |
409 | } | |
410 | ||
6f505b16 | 411 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
80f40ee4 | 412 | list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) |
6f505b16 | 413 | |
6f505b16 PZ |
414 | #define for_each_sched_rt_entity(rt_se) \ |
415 | for (; rt_se; rt_se = rt_se->parent) | |
416 | ||
417 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
418 | { | |
419 | return rt_se->my_q; | |
420 | } | |
421 | ||
37dad3fc | 422 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head); |
6f505b16 PZ |
423 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se); |
424 | ||
9f0c1e56 | 425 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 426 | { |
f6121f4f | 427 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
74b7eb58 YZ |
428 | struct sched_rt_entity *rt_se; |
429 | ||
0c3b9168 BS |
430 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
431 | ||
432 | rt_se = rt_rq->tg->rt_se[cpu]; | |
6f505b16 | 433 | |
f6121f4f DF |
434 | if (rt_rq->rt_nr_running) { |
435 | if (rt_se && !on_rt_rq(rt_se)) | |
37dad3fc | 436 | enqueue_rt_entity(rt_se, false); |
e864c499 | 437 | if (rt_rq->highest_prio.curr < curr->prio) |
1020387f | 438 | resched_task(curr); |
6f505b16 PZ |
439 | } |
440 | } | |
441 | ||
9f0c1e56 | 442 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 | 443 | { |
74b7eb58 | 444 | struct sched_rt_entity *rt_se; |
0c3b9168 | 445 | int cpu = cpu_of(rq_of_rt_rq(rt_rq)); |
74b7eb58 | 446 | |
0c3b9168 | 447 | rt_se = rt_rq->tg->rt_se[cpu]; |
6f505b16 PZ |
448 | |
449 | if (rt_se && on_rt_rq(rt_se)) | |
450 | dequeue_rt_entity(rt_se); | |
451 | } | |
452 | ||
23b0fdfc PZ |
453 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
454 | { | |
455 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; | |
456 | } | |
457 | ||
458 | static int rt_se_boosted(struct sched_rt_entity *rt_se) | |
459 | { | |
460 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
461 | struct task_struct *p; | |
462 | ||
463 | if (rt_rq) | |
464 | return !!rt_rq->rt_nr_boosted; | |
465 | ||
466 | p = rt_task_of(rt_se); | |
467 | return p->prio != p->normal_prio; | |
468 | } | |
469 | ||
d0b27fa7 | 470 | #ifdef CONFIG_SMP |
c6c4927b | 471 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 PZ |
472 | { |
473 | return cpu_rq(smp_processor_id())->rd->span; | |
474 | } | |
6f505b16 | 475 | #else |
c6c4927b | 476 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 477 | { |
c6c4927b | 478 | return cpu_online_mask; |
d0b27fa7 PZ |
479 | } |
480 | #endif | |
6f505b16 | 481 | |
d0b27fa7 PZ |
482 | static inline |
483 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
6f505b16 | 484 | { |
d0b27fa7 PZ |
485 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
486 | } | |
9f0c1e56 | 487 | |
ac086bc2 PZ |
488 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
489 | { | |
490 | return &rt_rq->tg->rt_bandwidth; | |
491 | } | |
492 | ||
55e12e5e | 493 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
494 | |
495 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) | |
496 | { | |
ac086bc2 PZ |
497 | return rt_rq->rt_runtime; |
498 | } | |
499 | ||
500 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) | |
501 | { | |
502 | return ktime_to_ns(def_rt_bandwidth.rt_period); | |
6f505b16 PZ |
503 | } |
504 | ||
ec514c48 CX |
505 | typedef struct rt_rq *rt_rq_iter_t; |
506 | ||
507 | #define for_each_rt_rq(rt_rq, iter, rq) \ | |
508 | for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
509 | ||
3d4b47b4 PZ |
510 | static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) |
511 | { | |
512 | } | |
513 | ||
514 | static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq) | |
515 | { | |
516 | } | |
517 | ||
6f505b16 PZ |
518 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
519 | for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) | |
520 | ||
6f505b16 PZ |
521 | #define for_each_sched_rt_entity(rt_se) \ |
522 | for (; rt_se; rt_se = NULL) | |
523 | ||
524 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) | |
525 | { | |
526 | return NULL; | |
527 | } | |
528 | ||
9f0c1e56 | 529 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
6f505b16 | 530 | { |
f3ade837 JB |
531 | if (rt_rq->rt_nr_running) |
532 | resched_task(rq_of_rt_rq(rt_rq)->curr); | |
6f505b16 PZ |
533 | } |
534 | ||
9f0c1e56 | 535 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
6f505b16 PZ |
536 | { |
537 | } | |
538 | ||
23b0fdfc PZ |
539 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
540 | { | |
541 | return rt_rq->rt_throttled; | |
542 | } | |
d0b27fa7 | 543 | |
c6c4927b | 544 | static inline const struct cpumask *sched_rt_period_mask(void) |
d0b27fa7 | 545 | { |
c6c4927b | 546 | return cpu_online_mask; |
d0b27fa7 PZ |
547 | } |
548 | ||
549 | static inline | |
550 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) | |
551 | { | |
552 | return &cpu_rq(cpu)->rt; | |
553 | } | |
554 | ||
ac086bc2 PZ |
555 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
556 | { | |
557 | return &def_rt_bandwidth; | |
558 | } | |
559 | ||
55e12e5e | 560 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 561 | |
ac086bc2 | 562 | #ifdef CONFIG_SMP |
78333cdd PZ |
563 | /* |
564 | * We ran out of runtime, see if we can borrow some from our neighbours. | |
565 | */ | |
b79f3833 | 566 | static int do_balance_runtime(struct rt_rq *rt_rq) |
ac086bc2 PZ |
567 | { |
568 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); | |
569 | struct root_domain *rd = cpu_rq(smp_processor_id())->rd; | |
570 | int i, weight, more = 0; | |
571 | u64 rt_period; | |
572 | ||
c6c4927b | 573 | weight = cpumask_weight(rd->span); |
ac086bc2 | 574 | |
0986b11b | 575 | raw_spin_lock(&rt_b->rt_runtime_lock); |
ac086bc2 | 576 | rt_period = ktime_to_ns(rt_b->rt_period); |
c6c4927b | 577 | for_each_cpu(i, rd->span) { |
ac086bc2 PZ |
578 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
579 | s64 diff; | |
580 | ||
581 | if (iter == rt_rq) | |
582 | continue; | |
583 | ||
0986b11b | 584 | raw_spin_lock(&iter->rt_runtime_lock); |
78333cdd PZ |
585 | /* |
586 | * Either all rqs have inf runtime and there's nothing to steal | |
587 | * or __disable_runtime() below sets a specific rq to inf to | |
588 | * indicate its been disabled and disalow stealing. | |
589 | */ | |
7def2be1 PZ |
590 | if (iter->rt_runtime == RUNTIME_INF) |
591 | goto next; | |
592 | ||
78333cdd PZ |
593 | /* |
594 | * From runqueues with spare time, take 1/n part of their | |
595 | * spare time, but no more than our period. | |
596 | */ | |
ac086bc2 PZ |
597 | diff = iter->rt_runtime - iter->rt_time; |
598 | if (diff > 0) { | |
58838cf3 | 599 | diff = div_u64((u64)diff, weight); |
ac086bc2 PZ |
600 | if (rt_rq->rt_runtime + diff > rt_period) |
601 | diff = rt_period - rt_rq->rt_runtime; | |
602 | iter->rt_runtime -= diff; | |
603 | rt_rq->rt_runtime += diff; | |
604 | more = 1; | |
605 | if (rt_rq->rt_runtime == rt_period) { | |
0986b11b | 606 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 PZ |
607 | break; |
608 | } | |
609 | } | |
7def2be1 | 610 | next: |
0986b11b | 611 | raw_spin_unlock(&iter->rt_runtime_lock); |
ac086bc2 | 612 | } |
0986b11b | 613 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
ac086bc2 PZ |
614 | |
615 | return more; | |
616 | } | |
7def2be1 | 617 | |
78333cdd PZ |
618 | /* |
619 | * Ensure this RQ takes back all the runtime it lend to its neighbours. | |
620 | */ | |
7def2be1 PZ |
621 | static void __disable_runtime(struct rq *rq) |
622 | { | |
623 | struct root_domain *rd = rq->rd; | |
ec514c48 | 624 | rt_rq_iter_t iter; |
7def2be1 PZ |
625 | struct rt_rq *rt_rq; |
626 | ||
627 | if (unlikely(!scheduler_running)) | |
628 | return; | |
629 | ||
ec514c48 | 630 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
631 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
632 | s64 want; | |
633 | int i; | |
634 | ||
0986b11b TG |
635 | raw_spin_lock(&rt_b->rt_runtime_lock); |
636 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
78333cdd PZ |
637 | /* |
638 | * Either we're all inf and nobody needs to borrow, or we're | |
639 | * already disabled and thus have nothing to do, or we have | |
640 | * exactly the right amount of runtime to take out. | |
641 | */ | |
7def2be1 PZ |
642 | if (rt_rq->rt_runtime == RUNTIME_INF || |
643 | rt_rq->rt_runtime == rt_b->rt_runtime) | |
644 | goto balanced; | |
0986b11b | 645 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
7def2be1 | 646 | |
78333cdd PZ |
647 | /* |
648 | * Calculate the difference between what we started out with | |
649 | * and what we current have, that's the amount of runtime | |
650 | * we lend and now have to reclaim. | |
651 | */ | |
7def2be1 PZ |
652 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
653 | ||
78333cdd PZ |
654 | /* |
655 | * Greedy reclaim, take back as much as we can. | |
656 | */ | |
c6c4927b | 657 | for_each_cpu(i, rd->span) { |
7def2be1 PZ |
658 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
659 | s64 diff; | |
660 | ||
78333cdd PZ |
661 | /* |
662 | * Can't reclaim from ourselves or disabled runqueues. | |
663 | */ | |
f1679d08 | 664 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
7def2be1 PZ |
665 | continue; |
666 | ||
0986b11b | 667 | raw_spin_lock(&iter->rt_runtime_lock); |
7def2be1 PZ |
668 | if (want > 0) { |
669 | diff = min_t(s64, iter->rt_runtime, want); | |
670 | iter->rt_runtime -= diff; | |
671 | want -= diff; | |
672 | } else { | |
673 | iter->rt_runtime -= want; | |
674 | want -= want; | |
675 | } | |
0986b11b | 676 | raw_spin_unlock(&iter->rt_runtime_lock); |
7def2be1 PZ |
677 | |
678 | if (!want) | |
679 | break; | |
680 | } | |
681 | ||
0986b11b | 682 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
78333cdd PZ |
683 | /* |
684 | * We cannot be left wanting - that would mean some runtime | |
685 | * leaked out of the system. | |
686 | */ | |
7def2be1 PZ |
687 | BUG_ON(want); |
688 | balanced: | |
78333cdd PZ |
689 | /* |
690 | * Disable all the borrow logic by pretending we have inf | |
691 | * runtime - in which case borrowing doesn't make sense. | |
692 | */ | |
7def2be1 | 693 | rt_rq->rt_runtime = RUNTIME_INF; |
0986b11b TG |
694 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
695 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
696 | } |
697 | } | |
698 | ||
699 | static void disable_runtime(struct rq *rq) | |
700 | { | |
701 | unsigned long flags; | |
702 | ||
05fa785c | 703 | raw_spin_lock_irqsave(&rq->lock, flags); |
7def2be1 | 704 | __disable_runtime(rq); |
05fa785c | 705 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
7def2be1 PZ |
706 | } |
707 | ||
708 | static void __enable_runtime(struct rq *rq) | |
709 | { | |
ec514c48 | 710 | rt_rq_iter_t iter; |
7def2be1 PZ |
711 | struct rt_rq *rt_rq; |
712 | ||
713 | if (unlikely(!scheduler_running)) | |
714 | return; | |
715 | ||
78333cdd PZ |
716 | /* |
717 | * Reset each runqueue's bandwidth settings | |
718 | */ | |
ec514c48 | 719 | for_each_rt_rq(rt_rq, iter, rq) { |
7def2be1 PZ |
720 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
721 | ||
0986b11b TG |
722 | raw_spin_lock(&rt_b->rt_runtime_lock); |
723 | raw_spin_lock(&rt_rq->rt_runtime_lock); | |
7def2be1 PZ |
724 | rt_rq->rt_runtime = rt_b->rt_runtime; |
725 | rt_rq->rt_time = 0; | |
baf25731 | 726 | rt_rq->rt_throttled = 0; |
0986b11b TG |
727 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
728 | raw_spin_unlock(&rt_b->rt_runtime_lock); | |
7def2be1 PZ |
729 | } |
730 | } | |
731 | ||
732 | static void enable_runtime(struct rq *rq) | |
733 | { | |
734 | unsigned long flags; | |
735 | ||
05fa785c | 736 | raw_spin_lock_irqsave(&rq->lock, flags); |
7def2be1 | 737 | __enable_runtime(rq); |
05fa785c | 738 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
7def2be1 PZ |
739 | } |
740 | ||
029632fb PZ |
741 | int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu) |
742 | { | |
743 | int cpu = (int)(long)hcpu; | |
744 | ||
745 | switch (action) { | |
746 | case CPU_DOWN_PREPARE: | |
747 | case CPU_DOWN_PREPARE_FROZEN: | |
748 | disable_runtime(cpu_rq(cpu)); | |
749 | return NOTIFY_OK; | |
750 | ||
751 | case CPU_DOWN_FAILED: | |
752 | case CPU_DOWN_FAILED_FROZEN: | |
753 | case CPU_ONLINE: | |
754 | case CPU_ONLINE_FROZEN: | |
755 | enable_runtime(cpu_rq(cpu)); | |
756 | return NOTIFY_OK; | |
757 | ||
758 | default: | |
759 | return NOTIFY_DONE; | |
760 | } | |
761 | } | |
762 | ||
eff6549b PZ |
763 | static int balance_runtime(struct rt_rq *rt_rq) |
764 | { | |
765 | int more = 0; | |
766 | ||
4a6184ce PZ |
767 | if (!sched_feat(RT_RUNTIME_SHARE)) |
768 | return more; | |
769 | ||
eff6549b | 770 | if (rt_rq->rt_time > rt_rq->rt_runtime) { |
0986b11b | 771 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
eff6549b | 772 | more = do_balance_runtime(rt_rq); |
0986b11b | 773 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
774 | } |
775 | ||
776 | return more; | |
777 | } | |
55e12e5e | 778 | #else /* !CONFIG_SMP */ |
eff6549b PZ |
779 | static inline int balance_runtime(struct rt_rq *rt_rq) |
780 | { | |
781 | return 0; | |
782 | } | |
55e12e5e | 783 | #endif /* CONFIG_SMP */ |
ac086bc2 | 784 | |
eff6549b PZ |
785 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
786 | { | |
42c62a58 | 787 | int i, idle = 1, throttled = 0; |
c6c4927b | 788 | const struct cpumask *span; |
eff6549b | 789 | |
eff6549b | 790 | span = sched_rt_period_mask(); |
c6c4927b | 791 | for_each_cpu(i, span) { |
eff6549b PZ |
792 | int enqueue = 0; |
793 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); | |
794 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
795 | ||
05fa785c | 796 | raw_spin_lock(&rq->lock); |
eff6549b PZ |
797 | if (rt_rq->rt_time) { |
798 | u64 runtime; | |
799 | ||
0986b11b | 800 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
eff6549b PZ |
801 | if (rt_rq->rt_throttled) |
802 | balance_runtime(rt_rq); | |
803 | runtime = rt_rq->rt_runtime; | |
804 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); | |
805 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { | |
806 | rt_rq->rt_throttled = 0; | |
807 | enqueue = 1; | |
61eadef6 MG |
808 | |
809 | /* | |
810 | * Force a clock update if the CPU was idle, | |
811 | * lest wakeup -> unthrottle time accumulate. | |
812 | */ | |
813 | if (rt_rq->rt_nr_running && rq->curr == rq->idle) | |
814 | rq->skip_clock_update = -1; | |
eff6549b PZ |
815 | } |
816 | if (rt_rq->rt_time || rt_rq->rt_nr_running) | |
817 | idle = 0; | |
0986b11b | 818 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
0c3b9168 | 819 | } else if (rt_rq->rt_nr_running) { |
6c3df255 | 820 | idle = 0; |
0c3b9168 BS |
821 | if (!rt_rq_throttled(rt_rq)) |
822 | enqueue = 1; | |
823 | } | |
42c62a58 PZ |
824 | if (rt_rq->rt_throttled) |
825 | throttled = 1; | |
eff6549b PZ |
826 | |
827 | if (enqueue) | |
828 | sched_rt_rq_enqueue(rt_rq); | |
05fa785c | 829 | raw_spin_unlock(&rq->lock); |
eff6549b PZ |
830 | } |
831 | ||
42c62a58 PZ |
832 | if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) |
833 | return 1; | |
834 | ||
eff6549b PZ |
835 | return idle; |
836 | } | |
ac086bc2 | 837 | |
6f505b16 PZ |
838 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
839 | { | |
052f1dc7 | 840 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
841 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
842 | ||
843 | if (rt_rq) | |
e864c499 | 844 | return rt_rq->highest_prio.curr; |
6f505b16 PZ |
845 | #endif |
846 | ||
847 | return rt_task_of(rt_se)->prio; | |
848 | } | |
849 | ||
9f0c1e56 | 850 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
6f505b16 | 851 | { |
9f0c1e56 | 852 | u64 runtime = sched_rt_runtime(rt_rq); |
fa85ae24 | 853 | |
fa85ae24 | 854 | if (rt_rq->rt_throttled) |
23b0fdfc | 855 | return rt_rq_throttled(rt_rq); |
fa85ae24 | 856 | |
5b680fd6 | 857 | if (runtime >= sched_rt_period(rt_rq)) |
ac086bc2 PZ |
858 | return 0; |
859 | ||
b79f3833 PZ |
860 | balance_runtime(rt_rq); |
861 | runtime = sched_rt_runtime(rt_rq); | |
862 | if (runtime == RUNTIME_INF) | |
863 | return 0; | |
ac086bc2 | 864 | |
9f0c1e56 | 865 | if (rt_rq->rt_time > runtime) { |
7abc63b1 PZ |
866 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
867 | ||
868 | /* | |
869 | * Don't actually throttle groups that have no runtime assigned | |
870 | * but accrue some time due to boosting. | |
871 | */ | |
872 | if (likely(rt_b->rt_runtime)) { | |
3ccf3e83 PZ |
873 | static bool once = false; |
874 | ||
7abc63b1 | 875 | rt_rq->rt_throttled = 1; |
3ccf3e83 PZ |
876 | |
877 | if (!once) { | |
878 | once = true; | |
879 | printk_sched("sched: RT throttling activated\n"); | |
880 | } | |
7abc63b1 PZ |
881 | } else { |
882 | /* | |
883 | * In case we did anyway, make it go away, | |
884 | * replenishment is a joke, since it will replenish us | |
885 | * with exactly 0 ns. | |
886 | */ | |
887 | rt_rq->rt_time = 0; | |
888 | } | |
889 | ||
23b0fdfc | 890 | if (rt_rq_throttled(rt_rq)) { |
9f0c1e56 | 891 | sched_rt_rq_dequeue(rt_rq); |
23b0fdfc PZ |
892 | return 1; |
893 | } | |
fa85ae24 PZ |
894 | } |
895 | ||
896 | return 0; | |
897 | } | |
898 | ||
bb44e5d1 IM |
899 | /* |
900 | * Update the current task's runtime statistics. Skip current tasks that | |
901 | * are not in our scheduling class. | |
902 | */ | |
a9957449 | 903 | static void update_curr_rt(struct rq *rq) |
bb44e5d1 IM |
904 | { |
905 | struct task_struct *curr = rq->curr; | |
6f505b16 PZ |
906 | struct sched_rt_entity *rt_se = &curr->rt; |
907 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
bb44e5d1 IM |
908 | u64 delta_exec; |
909 | ||
06c3bc65 | 910 | if (curr->sched_class != &rt_sched_class) |
bb44e5d1 IM |
911 | return; |
912 | ||
305e6835 | 913 | delta_exec = rq->clock_task - curr->se.exec_start; |
bb44e5d1 IM |
914 | if (unlikely((s64)delta_exec < 0)) |
915 | delta_exec = 0; | |
6cfb0d5d | 916 | |
42c62a58 PZ |
917 | schedstat_set(curr->se.statistics.exec_max, |
918 | max(curr->se.statistics.exec_max, delta_exec)); | |
bb44e5d1 IM |
919 | |
920 | curr->se.sum_exec_runtime += delta_exec; | |
f06febc9 FM |
921 | account_group_exec_runtime(curr, delta_exec); |
922 | ||
305e6835 | 923 | curr->se.exec_start = rq->clock_task; |
d842de87 | 924 | cpuacct_charge(curr, delta_exec); |
fa85ae24 | 925 | |
e9e9250b PZ |
926 | sched_rt_avg_update(rq, delta_exec); |
927 | ||
0b148fa0 PZ |
928 | if (!rt_bandwidth_enabled()) |
929 | return; | |
930 | ||
354d60c2 DG |
931 | for_each_sched_rt_entity(rt_se) { |
932 | rt_rq = rt_rq_of_se(rt_se); | |
933 | ||
cc2991cf | 934 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
0986b11b | 935 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
cc2991cf PZ |
936 | rt_rq->rt_time += delta_exec; |
937 | if (sched_rt_runtime_exceeded(rt_rq)) | |
938 | resched_task(curr); | |
0986b11b | 939 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
cc2991cf | 940 | } |
354d60c2 | 941 | } |
bb44e5d1 IM |
942 | } |
943 | ||
398a153b | 944 | #if defined CONFIG_SMP |
e864c499 | 945 | |
398a153b GH |
946 | static void |
947 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
63489e45 | 948 | { |
4d984277 | 949 | struct rq *rq = rq_of_rt_rq(rt_rq); |
1f11eb6a | 950 | |
5181f4a4 SR |
951 | if (rq->online && prio < prev_prio) |
952 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); | |
398a153b | 953 | } |
73fe6aae | 954 | |
398a153b GH |
955 | static void |
956 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) | |
957 | { | |
958 | struct rq *rq = rq_of_rt_rq(rt_rq); | |
d0b27fa7 | 959 | |
398a153b GH |
960 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) |
961 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); | |
63489e45 SR |
962 | } |
963 | ||
398a153b GH |
964 | #else /* CONFIG_SMP */ |
965 | ||
6f505b16 | 966 | static inline |
398a153b GH |
967 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
968 | static inline | |
969 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} | |
970 | ||
971 | #endif /* CONFIG_SMP */ | |
6e0534f2 | 972 | |
052f1dc7 | 973 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
398a153b GH |
974 | static void |
975 | inc_rt_prio(struct rt_rq *rt_rq, int prio) | |
976 | { | |
977 | int prev_prio = rt_rq->highest_prio.curr; | |
978 | ||
979 | if (prio < prev_prio) | |
980 | rt_rq->highest_prio.curr = prio; | |
981 | ||
982 | inc_rt_prio_smp(rt_rq, prio, prev_prio); | |
983 | } | |
984 | ||
985 | static void | |
986 | dec_rt_prio(struct rt_rq *rt_rq, int prio) | |
987 | { | |
988 | int prev_prio = rt_rq->highest_prio.curr; | |
989 | ||
6f505b16 | 990 | if (rt_rq->rt_nr_running) { |
764a9d6f | 991 | |
398a153b | 992 | WARN_ON(prio < prev_prio); |
764a9d6f | 993 | |
e864c499 | 994 | /* |
398a153b GH |
995 | * This may have been our highest task, and therefore |
996 | * we may have some recomputation to do | |
e864c499 | 997 | */ |
398a153b | 998 | if (prio == prev_prio) { |
e864c499 GH |
999 | struct rt_prio_array *array = &rt_rq->active; |
1000 | ||
1001 | rt_rq->highest_prio.curr = | |
764a9d6f | 1002 | sched_find_first_bit(array->bitmap); |
e864c499 GH |
1003 | } |
1004 | ||
764a9d6f | 1005 | } else |
e864c499 | 1006 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
73fe6aae | 1007 | |
398a153b GH |
1008 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
1009 | } | |
1f11eb6a | 1010 | |
398a153b GH |
1011 | #else |
1012 | ||
1013 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1014 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} | |
1015 | ||
1016 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ | |
6e0534f2 | 1017 | |
052f1dc7 | 1018 | #ifdef CONFIG_RT_GROUP_SCHED |
398a153b GH |
1019 | |
1020 | static void | |
1021 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1022 | { | |
1023 | if (rt_se_boosted(rt_se)) | |
1024 | rt_rq->rt_nr_boosted++; | |
1025 | ||
1026 | if (rt_rq->tg) | |
1027 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); | |
1028 | } | |
1029 | ||
1030 | static void | |
1031 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1032 | { | |
23b0fdfc PZ |
1033 | if (rt_se_boosted(rt_se)) |
1034 | rt_rq->rt_nr_boosted--; | |
1035 | ||
1036 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); | |
398a153b GH |
1037 | } |
1038 | ||
1039 | #else /* CONFIG_RT_GROUP_SCHED */ | |
1040 | ||
1041 | static void | |
1042 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1043 | { | |
1044 | start_rt_bandwidth(&def_rt_bandwidth); | |
1045 | } | |
1046 | ||
1047 | static inline | |
1048 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} | |
1049 | ||
1050 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
1051 | ||
1052 | static inline | |
1053 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1054 | { | |
1055 | int prio = rt_se_prio(rt_se); | |
1056 | ||
1057 | WARN_ON(!rt_prio(prio)); | |
1058 | rt_rq->rt_nr_running++; | |
1059 | ||
1060 | inc_rt_prio(rt_rq, prio); | |
1061 | inc_rt_migration(rt_se, rt_rq); | |
1062 | inc_rt_group(rt_se, rt_rq); | |
1063 | } | |
1064 | ||
1065 | static inline | |
1066 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) | |
1067 | { | |
1068 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); | |
1069 | WARN_ON(!rt_rq->rt_nr_running); | |
1070 | rt_rq->rt_nr_running--; | |
1071 | ||
1072 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); | |
1073 | dec_rt_migration(rt_se, rt_rq); | |
1074 | dec_rt_group(rt_se, rt_rq); | |
63489e45 SR |
1075 | } |
1076 | ||
37dad3fc | 1077 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head) |
bb44e5d1 | 1078 | { |
6f505b16 PZ |
1079 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
1080 | struct rt_prio_array *array = &rt_rq->active; | |
1081 | struct rt_rq *group_rq = group_rt_rq(rt_se); | |
20b6331b | 1082 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
bb44e5d1 | 1083 | |
ad2a3f13 PZ |
1084 | /* |
1085 | * Don't enqueue the group if its throttled, or when empty. | |
1086 | * The latter is a consequence of the former when a child group | |
1087 | * get throttled and the current group doesn't have any other | |
1088 | * active members. | |
1089 | */ | |
1090 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) | |
6f505b16 | 1091 | return; |
63489e45 | 1092 | |
3d4b47b4 PZ |
1093 | if (!rt_rq->rt_nr_running) |
1094 | list_add_leaf_rt_rq(rt_rq); | |
1095 | ||
37dad3fc TG |
1096 | if (head) |
1097 | list_add(&rt_se->run_list, queue); | |
1098 | else | |
1099 | list_add_tail(&rt_se->run_list, queue); | |
6f505b16 | 1100 | __set_bit(rt_se_prio(rt_se), array->bitmap); |
78f2c7db | 1101 | |
6f505b16 PZ |
1102 | inc_rt_tasks(rt_se, rt_rq); |
1103 | } | |
1104 | ||
ad2a3f13 | 1105 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) |
6f505b16 PZ |
1106 | { |
1107 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); | |
1108 | struct rt_prio_array *array = &rt_rq->active; | |
1109 | ||
1110 | list_del_init(&rt_se->run_list); | |
1111 | if (list_empty(array->queue + rt_se_prio(rt_se))) | |
1112 | __clear_bit(rt_se_prio(rt_se), array->bitmap); | |
1113 | ||
1114 | dec_rt_tasks(rt_se, rt_rq); | |
3d4b47b4 PZ |
1115 | if (!rt_rq->rt_nr_running) |
1116 | list_del_leaf_rt_rq(rt_rq); | |
6f505b16 PZ |
1117 | } |
1118 | ||
1119 | /* | |
1120 | * Because the prio of an upper entry depends on the lower | |
1121 | * entries, we must remove entries top - down. | |
6f505b16 | 1122 | */ |
ad2a3f13 | 1123 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se) |
6f505b16 | 1124 | { |
ad2a3f13 | 1125 | struct sched_rt_entity *back = NULL; |
6f505b16 | 1126 | |
58d6c2d7 PZ |
1127 | for_each_sched_rt_entity(rt_se) { |
1128 | rt_se->back = back; | |
1129 | back = rt_se; | |
1130 | } | |
1131 | ||
1132 | for (rt_se = back; rt_se; rt_se = rt_se->back) { | |
1133 | if (on_rt_rq(rt_se)) | |
ad2a3f13 PZ |
1134 | __dequeue_rt_entity(rt_se); |
1135 | } | |
1136 | } | |
1137 | ||
37dad3fc | 1138 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head) |
ad2a3f13 PZ |
1139 | { |
1140 | dequeue_rt_stack(rt_se); | |
1141 | for_each_sched_rt_entity(rt_se) | |
37dad3fc | 1142 | __enqueue_rt_entity(rt_se, head); |
ad2a3f13 PZ |
1143 | } |
1144 | ||
1145 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se) | |
1146 | { | |
1147 | dequeue_rt_stack(rt_se); | |
1148 | ||
1149 | for_each_sched_rt_entity(rt_se) { | |
1150 | struct rt_rq *rt_rq = group_rt_rq(rt_se); | |
1151 | ||
1152 | if (rt_rq && rt_rq->rt_nr_running) | |
37dad3fc | 1153 | __enqueue_rt_entity(rt_se, false); |
58d6c2d7 | 1154 | } |
bb44e5d1 IM |
1155 | } |
1156 | ||
1157 | /* | |
1158 | * Adding/removing a task to/from a priority array: | |
1159 | */ | |
ea87bb78 | 1160 | static void |
371fd7e7 | 1161 | enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
6f505b16 PZ |
1162 | { |
1163 | struct sched_rt_entity *rt_se = &p->rt; | |
1164 | ||
371fd7e7 | 1165 | if (flags & ENQUEUE_WAKEUP) |
6f505b16 PZ |
1166 | rt_se->timeout = 0; |
1167 | ||
371fd7e7 | 1168 | enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD); |
c09595f6 | 1169 | |
29baa747 | 1170 | if (!task_current(rq, p) && p->nr_cpus_allowed > 1) |
917b627d | 1171 | enqueue_pushable_task(rq, p); |
953bfcd1 PT |
1172 | |
1173 | inc_nr_running(rq); | |
6f505b16 PZ |
1174 | } |
1175 | ||
371fd7e7 | 1176 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1177 | { |
6f505b16 | 1178 | struct sched_rt_entity *rt_se = &p->rt; |
bb44e5d1 | 1179 | |
f1e14ef6 | 1180 | update_curr_rt(rq); |
ad2a3f13 | 1181 | dequeue_rt_entity(rt_se); |
c09595f6 | 1182 | |
917b627d | 1183 | dequeue_pushable_task(rq, p); |
953bfcd1 PT |
1184 | |
1185 | dec_nr_running(rq); | |
bb44e5d1 IM |
1186 | } |
1187 | ||
1188 | /* | |
60686317 RW |
1189 | * Put task to the head or the end of the run list without the overhead of |
1190 | * dequeue followed by enqueue. | |
bb44e5d1 | 1191 | */ |
7ebefa8c DA |
1192 | static void |
1193 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) | |
6f505b16 | 1194 | { |
1cdad715 | 1195 | if (on_rt_rq(rt_se)) { |
7ebefa8c DA |
1196 | struct rt_prio_array *array = &rt_rq->active; |
1197 | struct list_head *queue = array->queue + rt_se_prio(rt_se); | |
1198 | ||
1199 | if (head) | |
1200 | list_move(&rt_se->run_list, queue); | |
1201 | else | |
1202 | list_move_tail(&rt_se->run_list, queue); | |
1cdad715 | 1203 | } |
6f505b16 PZ |
1204 | } |
1205 | ||
7ebefa8c | 1206 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
bb44e5d1 | 1207 | { |
6f505b16 PZ |
1208 | struct sched_rt_entity *rt_se = &p->rt; |
1209 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1210 | |
6f505b16 PZ |
1211 | for_each_sched_rt_entity(rt_se) { |
1212 | rt_rq = rt_rq_of_se(rt_se); | |
7ebefa8c | 1213 | requeue_rt_entity(rt_rq, rt_se, head); |
6f505b16 | 1214 | } |
bb44e5d1 IM |
1215 | } |
1216 | ||
6f505b16 | 1217 | static void yield_task_rt(struct rq *rq) |
bb44e5d1 | 1218 | { |
7ebefa8c | 1219 | requeue_task_rt(rq, rq->curr, 0); |
bb44e5d1 IM |
1220 | } |
1221 | ||
e7693a36 | 1222 | #ifdef CONFIG_SMP |
318e0893 GH |
1223 | static int find_lowest_rq(struct task_struct *task); |
1224 | ||
0017d735 | 1225 | static int |
7608dec2 | 1226 | select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) |
e7693a36 | 1227 | { |
7608dec2 PZ |
1228 | struct task_struct *curr; |
1229 | struct rq *rq; | |
1230 | int cpu; | |
1231 | ||
7608dec2 | 1232 | cpu = task_cpu(p); |
c37495fd | 1233 | |
29baa747 | 1234 | if (p->nr_cpus_allowed == 1) |
76854c7e MG |
1235 | goto out; |
1236 | ||
c37495fd SR |
1237 | /* For anything but wake ups, just return the task_cpu */ |
1238 | if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK) | |
1239 | goto out; | |
1240 | ||
7608dec2 PZ |
1241 | rq = cpu_rq(cpu); |
1242 | ||
1243 | rcu_read_lock(); | |
1244 | curr = ACCESS_ONCE(rq->curr); /* unlocked access */ | |
1245 | ||
318e0893 | 1246 | /* |
7608dec2 | 1247 | * If the current task on @p's runqueue is an RT task, then |
e1f47d89 SR |
1248 | * try to see if we can wake this RT task up on another |
1249 | * runqueue. Otherwise simply start this RT task | |
1250 | * on its current runqueue. | |
1251 | * | |
43fa5460 SR |
1252 | * We want to avoid overloading runqueues. If the woken |
1253 | * task is a higher priority, then it will stay on this CPU | |
1254 | * and the lower prio task should be moved to another CPU. | |
1255 | * Even though this will probably make the lower prio task | |
1256 | * lose its cache, we do not want to bounce a higher task | |
1257 | * around just because it gave up its CPU, perhaps for a | |
1258 | * lock? | |
1259 | * | |
1260 | * For equal prio tasks, we just let the scheduler sort it out. | |
7608dec2 PZ |
1261 | * |
1262 | * Otherwise, just let it ride on the affined RQ and the | |
1263 | * post-schedule router will push the preempted task away | |
1264 | * | |
1265 | * This test is optimistic, if we get it wrong the load-balancer | |
1266 | * will have to sort it out. | |
318e0893 | 1267 | */ |
7608dec2 | 1268 | if (curr && unlikely(rt_task(curr)) && |
29baa747 | 1269 | (curr->nr_cpus_allowed < 2 || |
3be209a8 | 1270 | curr->prio <= p->prio) && |
29baa747 | 1271 | (p->nr_cpus_allowed > 1)) { |
7608dec2 | 1272 | int target = find_lowest_rq(p); |
318e0893 | 1273 | |
7608dec2 PZ |
1274 | if (target != -1) |
1275 | cpu = target; | |
318e0893 | 1276 | } |
7608dec2 | 1277 | rcu_read_unlock(); |
318e0893 | 1278 | |
c37495fd | 1279 | out: |
7608dec2 | 1280 | return cpu; |
e7693a36 | 1281 | } |
7ebefa8c DA |
1282 | |
1283 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) | |
1284 | { | |
29baa747 | 1285 | if (rq->curr->nr_cpus_allowed == 1) |
7ebefa8c DA |
1286 | return; |
1287 | ||
29baa747 | 1288 | if (p->nr_cpus_allowed != 1 |
13b8bd0a RR |
1289 | && cpupri_find(&rq->rd->cpupri, p, NULL)) |
1290 | return; | |
24600ce8 | 1291 | |
13b8bd0a RR |
1292 | if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) |
1293 | return; | |
7ebefa8c DA |
1294 | |
1295 | /* | |
1296 | * There appears to be other cpus that can accept | |
1297 | * current and none to run 'p', so lets reschedule | |
1298 | * to try and push current away: | |
1299 | */ | |
1300 | requeue_task_rt(rq, p, 1); | |
1301 | resched_task(rq->curr); | |
1302 | } | |
1303 | ||
e7693a36 GH |
1304 | #endif /* CONFIG_SMP */ |
1305 | ||
bb44e5d1 IM |
1306 | /* |
1307 | * Preempt the current task with a newly woken task if needed: | |
1308 | */ | |
7d478721 | 1309 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) |
bb44e5d1 | 1310 | { |
45c01e82 | 1311 | if (p->prio < rq->curr->prio) { |
bb44e5d1 | 1312 | resched_task(rq->curr); |
45c01e82 GH |
1313 | return; |
1314 | } | |
1315 | ||
1316 | #ifdef CONFIG_SMP | |
1317 | /* | |
1318 | * If: | |
1319 | * | |
1320 | * - the newly woken task is of equal priority to the current task | |
1321 | * - the newly woken task is non-migratable while current is migratable | |
1322 | * - current will be preempted on the next reschedule | |
1323 | * | |
1324 | * we should check to see if current can readily move to a different | |
1325 | * cpu. If so, we will reschedule to allow the push logic to try | |
1326 | * to move current somewhere else, making room for our non-migratable | |
1327 | * task. | |
1328 | */ | |
8dd0de8b | 1329 | if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr)) |
7ebefa8c | 1330 | check_preempt_equal_prio(rq, p); |
45c01e82 | 1331 | #endif |
bb44e5d1 IM |
1332 | } |
1333 | ||
6f505b16 PZ |
1334 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
1335 | struct rt_rq *rt_rq) | |
bb44e5d1 | 1336 | { |
6f505b16 PZ |
1337 | struct rt_prio_array *array = &rt_rq->active; |
1338 | struct sched_rt_entity *next = NULL; | |
bb44e5d1 IM |
1339 | struct list_head *queue; |
1340 | int idx; | |
1341 | ||
1342 | idx = sched_find_first_bit(array->bitmap); | |
6f505b16 | 1343 | BUG_ON(idx >= MAX_RT_PRIO); |
bb44e5d1 IM |
1344 | |
1345 | queue = array->queue + idx; | |
6f505b16 | 1346 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
326587b8 | 1347 | |
6f505b16 PZ |
1348 | return next; |
1349 | } | |
bb44e5d1 | 1350 | |
917b627d | 1351 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
6f505b16 PZ |
1352 | { |
1353 | struct sched_rt_entity *rt_se; | |
1354 | struct task_struct *p; | |
1355 | struct rt_rq *rt_rq; | |
bb44e5d1 | 1356 | |
6f505b16 PZ |
1357 | rt_rq = &rq->rt; |
1358 | ||
8e54a2c0 | 1359 | if (!rt_rq->rt_nr_running) |
6f505b16 PZ |
1360 | return NULL; |
1361 | ||
23b0fdfc | 1362 | if (rt_rq_throttled(rt_rq)) |
6f505b16 PZ |
1363 | return NULL; |
1364 | ||
1365 | do { | |
1366 | rt_se = pick_next_rt_entity(rq, rt_rq); | |
326587b8 | 1367 | BUG_ON(!rt_se); |
6f505b16 PZ |
1368 | rt_rq = group_rt_rq(rt_se); |
1369 | } while (rt_rq); | |
1370 | ||
1371 | p = rt_task_of(rt_se); | |
305e6835 | 1372 | p->se.exec_start = rq->clock_task; |
917b627d GH |
1373 | |
1374 | return p; | |
1375 | } | |
1376 | ||
1377 | static struct task_struct *pick_next_task_rt(struct rq *rq) | |
1378 | { | |
1379 | struct task_struct *p = _pick_next_task_rt(rq); | |
1380 | ||
1381 | /* The running task is never eligible for pushing */ | |
1382 | if (p) | |
1383 | dequeue_pushable_task(rq, p); | |
1384 | ||
bcf08df3 | 1385 | #ifdef CONFIG_SMP |
3f029d3c GH |
1386 | /* |
1387 | * We detect this state here so that we can avoid taking the RQ | |
1388 | * lock again later if there is no need to push | |
1389 | */ | |
1390 | rq->post_schedule = has_pushable_tasks(rq); | |
bcf08df3 | 1391 | #endif |
3f029d3c | 1392 | |
6f505b16 | 1393 | return p; |
bb44e5d1 IM |
1394 | } |
1395 | ||
31ee529c | 1396 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
bb44e5d1 | 1397 | { |
f1e14ef6 | 1398 | update_curr_rt(rq); |
917b627d GH |
1399 | |
1400 | /* | |
1401 | * The previous task needs to be made eligible for pushing | |
1402 | * if it is still active | |
1403 | */ | |
29baa747 | 1404 | if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1) |
917b627d | 1405 | enqueue_pushable_task(rq, p); |
bb44e5d1 IM |
1406 | } |
1407 | ||
681f3e68 | 1408 | #ifdef CONFIG_SMP |
6f505b16 | 1409 | |
e8fa1362 SR |
1410 | /* Only try algorithms three times */ |
1411 | #define RT_MAX_TRIES 3 | |
1412 | ||
f65eda4f SR |
1413 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
1414 | { | |
1415 | if (!task_running(rq, p) && | |
fa17b507 | 1416 | (cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) && |
29baa747 | 1417 | (p->nr_cpus_allowed > 1)) |
f65eda4f SR |
1418 | return 1; |
1419 | return 0; | |
1420 | } | |
1421 | ||
e8fa1362 | 1422 | /* Return the second highest RT task, NULL otherwise */ |
79064fbf | 1423 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) |
e8fa1362 | 1424 | { |
6f505b16 PZ |
1425 | struct task_struct *next = NULL; |
1426 | struct sched_rt_entity *rt_se; | |
1427 | struct rt_prio_array *array; | |
1428 | struct rt_rq *rt_rq; | |
e8fa1362 SR |
1429 | int idx; |
1430 | ||
6f505b16 PZ |
1431 | for_each_leaf_rt_rq(rt_rq, rq) { |
1432 | array = &rt_rq->active; | |
1433 | idx = sched_find_first_bit(array->bitmap); | |
49246274 | 1434 | next_idx: |
6f505b16 PZ |
1435 | if (idx >= MAX_RT_PRIO) |
1436 | continue; | |
1b028abc | 1437 | if (next && next->prio <= idx) |
6f505b16 PZ |
1438 | continue; |
1439 | list_for_each_entry(rt_se, array->queue + idx, run_list) { | |
3d07467b PZ |
1440 | struct task_struct *p; |
1441 | ||
1442 | if (!rt_entity_is_task(rt_se)) | |
1443 | continue; | |
1444 | ||
1445 | p = rt_task_of(rt_se); | |
6f505b16 PZ |
1446 | if (pick_rt_task(rq, p, cpu)) { |
1447 | next = p; | |
1448 | break; | |
1449 | } | |
1450 | } | |
1451 | if (!next) { | |
1452 | idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); | |
1453 | goto next_idx; | |
1454 | } | |
f65eda4f SR |
1455 | } |
1456 | ||
e8fa1362 SR |
1457 | return next; |
1458 | } | |
1459 | ||
0e3900e6 | 1460 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
e8fa1362 | 1461 | |
6e1254d2 GH |
1462 | static int find_lowest_rq(struct task_struct *task) |
1463 | { | |
1464 | struct sched_domain *sd; | |
96f874e2 | 1465 | struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); |
6e1254d2 GH |
1466 | int this_cpu = smp_processor_id(); |
1467 | int cpu = task_cpu(task); | |
06f90dbd | 1468 | |
0da938c4 SR |
1469 | /* Make sure the mask is initialized first */ |
1470 | if (unlikely(!lowest_mask)) | |
1471 | return -1; | |
1472 | ||
29baa747 | 1473 | if (task->nr_cpus_allowed == 1) |
6e0534f2 | 1474 | return -1; /* No other targets possible */ |
6e1254d2 | 1475 | |
6e0534f2 GH |
1476 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
1477 | return -1; /* No targets found */ | |
6e1254d2 GH |
1478 | |
1479 | /* | |
1480 | * At this point we have built a mask of cpus representing the | |
1481 | * lowest priority tasks in the system. Now we want to elect | |
1482 | * the best one based on our affinity and topology. | |
1483 | * | |
1484 | * We prioritize the last cpu that the task executed on since | |
1485 | * it is most likely cache-hot in that location. | |
1486 | */ | |
96f874e2 | 1487 | if (cpumask_test_cpu(cpu, lowest_mask)) |
6e1254d2 GH |
1488 | return cpu; |
1489 | ||
1490 | /* | |
1491 | * Otherwise, we consult the sched_domains span maps to figure | |
1492 | * out which cpu is logically closest to our hot cache data. | |
1493 | */ | |
e2c88063 RR |
1494 | if (!cpumask_test_cpu(this_cpu, lowest_mask)) |
1495 | this_cpu = -1; /* Skip this_cpu opt if not among lowest */ | |
6e1254d2 | 1496 | |
cd4ae6ad | 1497 | rcu_read_lock(); |
e2c88063 RR |
1498 | for_each_domain(cpu, sd) { |
1499 | if (sd->flags & SD_WAKE_AFFINE) { | |
1500 | int best_cpu; | |
6e1254d2 | 1501 | |
e2c88063 RR |
1502 | /* |
1503 | * "this_cpu" is cheaper to preempt than a | |
1504 | * remote processor. | |
1505 | */ | |
1506 | if (this_cpu != -1 && | |
cd4ae6ad XF |
1507 | cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { |
1508 | rcu_read_unlock(); | |
e2c88063 | 1509 | return this_cpu; |
cd4ae6ad | 1510 | } |
e2c88063 RR |
1511 | |
1512 | best_cpu = cpumask_first_and(lowest_mask, | |
1513 | sched_domain_span(sd)); | |
cd4ae6ad XF |
1514 | if (best_cpu < nr_cpu_ids) { |
1515 | rcu_read_unlock(); | |
e2c88063 | 1516 | return best_cpu; |
cd4ae6ad | 1517 | } |
6e1254d2 GH |
1518 | } |
1519 | } | |
cd4ae6ad | 1520 | rcu_read_unlock(); |
6e1254d2 GH |
1521 | |
1522 | /* | |
1523 | * And finally, if there were no matches within the domains | |
1524 | * just give the caller *something* to work with from the compatible | |
1525 | * locations. | |
1526 | */ | |
e2c88063 RR |
1527 | if (this_cpu != -1) |
1528 | return this_cpu; | |
1529 | ||
1530 | cpu = cpumask_any(lowest_mask); | |
1531 | if (cpu < nr_cpu_ids) | |
1532 | return cpu; | |
1533 | return -1; | |
07b4032c GH |
1534 | } |
1535 | ||
1536 | /* Will lock the rq it finds */ | |
4df64c0b | 1537 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
07b4032c GH |
1538 | { |
1539 | struct rq *lowest_rq = NULL; | |
07b4032c | 1540 | int tries; |
4df64c0b | 1541 | int cpu; |
e8fa1362 | 1542 | |
07b4032c GH |
1543 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
1544 | cpu = find_lowest_rq(task); | |
1545 | ||
2de0b463 | 1546 | if ((cpu == -1) || (cpu == rq->cpu)) |
e8fa1362 SR |
1547 | break; |
1548 | ||
07b4032c GH |
1549 | lowest_rq = cpu_rq(cpu); |
1550 | ||
e8fa1362 | 1551 | /* if the prio of this runqueue changed, try again */ |
07b4032c | 1552 | if (double_lock_balance(rq, lowest_rq)) { |
e8fa1362 SR |
1553 | /* |
1554 | * We had to unlock the run queue. In | |
1555 | * the mean time, task could have | |
1556 | * migrated already or had its affinity changed. | |
1557 | * Also make sure that it wasn't scheduled on its rq. | |
1558 | */ | |
07b4032c | 1559 | if (unlikely(task_rq(task) != rq || |
96f874e2 | 1560 | !cpumask_test_cpu(lowest_rq->cpu, |
fa17b507 | 1561 | tsk_cpus_allowed(task)) || |
07b4032c | 1562 | task_running(rq, task) || |
fd2f4419 | 1563 | !task->on_rq)) { |
4df64c0b | 1564 | |
7f1b4393 | 1565 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1566 | lowest_rq = NULL; |
1567 | break; | |
1568 | } | |
1569 | } | |
1570 | ||
1571 | /* If this rq is still suitable use it. */ | |
e864c499 | 1572 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
e8fa1362 SR |
1573 | break; |
1574 | ||
1575 | /* try again */ | |
1b12bbc7 | 1576 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 SR |
1577 | lowest_rq = NULL; |
1578 | } | |
1579 | ||
1580 | return lowest_rq; | |
1581 | } | |
1582 | ||
917b627d GH |
1583 | static struct task_struct *pick_next_pushable_task(struct rq *rq) |
1584 | { | |
1585 | struct task_struct *p; | |
1586 | ||
1587 | if (!has_pushable_tasks(rq)) | |
1588 | return NULL; | |
1589 | ||
1590 | p = plist_first_entry(&rq->rt.pushable_tasks, | |
1591 | struct task_struct, pushable_tasks); | |
1592 | ||
1593 | BUG_ON(rq->cpu != task_cpu(p)); | |
1594 | BUG_ON(task_current(rq, p)); | |
29baa747 | 1595 | BUG_ON(p->nr_cpus_allowed <= 1); |
917b627d | 1596 | |
fd2f4419 | 1597 | BUG_ON(!p->on_rq); |
917b627d GH |
1598 | BUG_ON(!rt_task(p)); |
1599 | ||
1600 | return p; | |
1601 | } | |
1602 | ||
e8fa1362 SR |
1603 | /* |
1604 | * If the current CPU has more than one RT task, see if the non | |
1605 | * running task can migrate over to a CPU that is running a task | |
1606 | * of lesser priority. | |
1607 | */ | |
697f0a48 | 1608 | static int push_rt_task(struct rq *rq) |
e8fa1362 SR |
1609 | { |
1610 | struct task_struct *next_task; | |
1611 | struct rq *lowest_rq; | |
311e800e | 1612 | int ret = 0; |
e8fa1362 | 1613 | |
a22d7fc1 GH |
1614 | if (!rq->rt.overloaded) |
1615 | return 0; | |
1616 | ||
917b627d | 1617 | next_task = pick_next_pushable_task(rq); |
e8fa1362 SR |
1618 | if (!next_task) |
1619 | return 0; | |
1620 | ||
cb297a3e CM |
1621 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
1622 | if (unlikely(task_running(rq, next_task))) | |
1623 | return 0; | |
1624 | #endif | |
1625 | ||
49246274 | 1626 | retry: |
697f0a48 | 1627 | if (unlikely(next_task == rq->curr)) { |
f65eda4f | 1628 | WARN_ON(1); |
e8fa1362 | 1629 | return 0; |
f65eda4f | 1630 | } |
e8fa1362 SR |
1631 | |
1632 | /* | |
1633 | * It's possible that the next_task slipped in of | |
1634 | * higher priority than current. If that's the case | |
1635 | * just reschedule current. | |
1636 | */ | |
697f0a48 GH |
1637 | if (unlikely(next_task->prio < rq->curr->prio)) { |
1638 | resched_task(rq->curr); | |
e8fa1362 SR |
1639 | return 0; |
1640 | } | |
1641 | ||
697f0a48 | 1642 | /* We might release rq lock */ |
e8fa1362 SR |
1643 | get_task_struct(next_task); |
1644 | ||
1645 | /* find_lock_lowest_rq locks the rq if found */ | |
697f0a48 | 1646 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
e8fa1362 SR |
1647 | if (!lowest_rq) { |
1648 | struct task_struct *task; | |
1649 | /* | |
311e800e | 1650 | * find_lock_lowest_rq releases rq->lock |
1563513d GH |
1651 | * so it is possible that next_task has migrated. |
1652 | * | |
1653 | * We need to make sure that the task is still on the same | |
1654 | * run-queue and is also still the next task eligible for | |
1655 | * pushing. | |
e8fa1362 | 1656 | */ |
917b627d | 1657 | task = pick_next_pushable_task(rq); |
1563513d GH |
1658 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
1659 | /* | |
311e800e HD |
1660 | * The task hasn't migrated, and is still the next |
1661 | * eligible task, but we failed to find a run-queue | |
1662 | * to push it to. Do not retry in this case, since | |
1663 | * other cpus will pull from us when ready. | |
1563513d | 1664 | */ |
1563513d | 1665 | goto out; |
e8fa1362 | 1666 | } |
917b627d | 1667 | |
1563513d GH |
1668 | if (!task) |
1669 | /* No more tasks, just exit */ | |
1670 | goto out; | |
1671 | ||
917b627d | 1672 | /* |
1563513d | 1673 | * Something has shifted, try again. |
917b627d | 1674 | */ |
1563513d GH |
1675 | put_task_struct(next_task); |
1676 | next_task = task; | |
1677 | goto retry; | |
e8fa1362 SR |
1678 | } |
1679 | ||
697f0a48 | 1680 | deactivate_task(rq, next_task, 0); |
e8fa1362 SR |
1681 | set_task_cpu(next_task, lowest_rq->cpu); |
1682 | activate_task(lowest_rq, next_task, 0); | |
311e800e | 1683 | ret = 1; |
e8fa1362 SR |
1684 | |
1685 | resched_task(lowest_rq->curr); | |
1686 | ||
1b12bbc7 | 1687 | double_unlock_balance(rq, lowest_rq); |
e8fa1362 | 1688 | |
e8fa1362 SR |
1689 | out: |
1690 | put_task_struct(next_task); | |
1691 | ||
311e800e | 1692 | return ret; |
e8fa1362 SR |
1693 | } |
1694 | ||
e8fa1362 SR |
1695 | static void push_rt_tasks(struct rq *rq) |
1696 | { | |
1697 | /* push_rt_task will return true if it moved an RT */ | |
1698 | while (push_rt_task(rq)) | |
1699 | ; | |
1700 | } | |
1701 | ||
f65eda4f SR |
1702 | static int pull_rt_task(struct rq *this_rq) |
1703 | { | |
80bf3171 | 1704 | int this_cpu = this_rq->cpu, ret = 0, cpu; |
a8728944 | 1705 | struct task_struct *p; |
f65eda4f | 1706 | struct rq *src_rq; |
f65eda4f | 1707 | |
637f5085 | 1708 | if (likely(!rt_overloaded(this_rq))) |
f65eda4f SR |
1709 | return 0; |
1710 | ||
c6c4927b | 1711 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
f65eda4f SR |
1712 | if (this_cpu == cpu) |
1713 | continue; | |
1714 | ||
1715 | src_rq = cpu_rq(cpu); | |
74ab8e4f GH |
1716 | |
1717 | /* | |
1718 | * Don't bother taking the src_rq->lock if the next highest | |
1719 | * task is known to be lower-priority than our current task. | |
1720 | * This may look racy, but if this value is about to go | |
1721 | * logically higher, the src_rq will push this task away. | |
1722 | * And if its going logically lower, we do not care | |
1723 | */ | |
1724 | if (src_rq->rt.highest_prio.next >= | |
1725 | this_rq->rt.highest_prio.curr) | |
1726 | continue; | |
1727 | ||
f65eda4f SR |
1728 | /* |
1729 | * We can potentially drop this_rq's lock in | |
1730 | * double_lock_balance, and another CPU could | |
a8728944 | 1731 | * alter this_rq |
f65eda4f | 1732 | */ |
a8728944 | 1733 | double_lock_balance(this_rq, src_rq); |
f65eda4f SR |
1734 | |
1735 | /* | |
1736 | * Are there still pullable RT tasks? | |
1737 | */ | |
614ee1f6 MG |
1738 | if (src_rq->rt.rt_nr_running <= 1) |
1739 | goto skip; | |
f65eda4f | 1740 | |
f65eda4f SR |
1741 | p = pick_next_highest_task_rt(src_rq, this_cpu); |
1742 | ||
1743 | /* | |
1744 | * Do we have an RT task that preempts | |
1745 | * the to-be-scheduled task? | |
1746 | */ | |
a8728944 | 1747 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
f65eda4f | 1748 | WARN_ON(p == src_rq->curr); |
fd2f4419 | 1749 | WARN_ON(!p->on_rq); |
f65eda4f SR |
1750 | |
1751 | /* | |
1752 | * There's a chance that p is higher in priority | |
1753 | * than what's currently running on its cpu. | |
1754 | * This is just that p is wakeing up and hasn't | |
1755 | * had a chance to schedule. We only pull | |
1756 | * p if it is lower in priority than the | |
a8728944 | 1757 | * current task on the run queue |
f65eda4f | 1758 | */ |
a8728944 | 1759 | if (p->prio < src_rq->curr->prio) |
614ee1f6 | 1760 | goto skip; |
f65eda4f SR |
1761 | |
1762 | ret = 1; | |
1763 | ||
1764 | deactivate_task(src_rq, p, 0); | |
1765 | set_task_cpu(p, this_cpu); | |
1766 | activate_task(this_rq, p, 0); | |
1767 | /* | |
1768 | * We continue with the search, just in | |
1769 | * case there's an even higher prio task | |
25985edc | 1770 | * in another runqueue. (low likelihood |
f65eda4f | 1771 | * but possible) |
f65eda4f | 1772 | */ |
f65eda4f | 1773 | } |
49246274 | 1774 | skip: |
1b12bbc7 | 1775 | double_unlock_balance(this_rq, src_rq); |
f65eda4f SR |
1776 | } |
1777 | ||
1778 | return ret; | |
1779 | } | |
1780 | ||
9a897c5a | 1781 | static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) |
f65eda4f SR |
1782 | { |
1783 | /* Try to pull RT tasks here if we lower this rq's prio */ | |
33c3d6c6 | 1784 | if (rq->rt.highest_prio.curr > prev->prio) |
f65eda4f SR |
1785 | pull_rt_task(rq); |
1786 | } | |
1787 | ||
9a897c5a | 1788 | static void post_schedule_rt(struct rq *rq) |
e8fa1362 | 1789 | { |
967fc046 | 1790 | push_rt_tasks(rq); |
e8fa1362 SR |
1791 | } |
1792 | ||
8ae121ac GH |
1793 | /* |
1794 | * If we are not running and we are not going to reschedule soon, we should | |
1795 | * try to push tasks away now | |
1796 | */ | |
efbbd05a | 1797 | static void task_woken_rt(struct rq *rq, struct task_struct *p) |
4642dafd | 1798 | { |
9a897c5a | 1799 | if (!task_running(rq, p) && |
8ae121ac | 1800 | !test_tsk_need_resched(rq->curr) && |
917b627d | 1801 | has_pushable_tasks(rq) && |
29baa747 | 1802 | p->nr_cpus_allowed > 1 && |
43fa5460 | 1803 | rt_task(rq->curr) && |
29baa747 | 1804 | (rq->curr->nr_cpus_allowed < 2 || |
3be209a8 | 1805 | rq->curr->prio <= p->prio)) |
4642dafd SR |
1806 | push_rt_tasks(rq); |
1807 | } | |
1808 | ||
cd8ba7cd | 1809 | static void set_cpus_allowed_rt(struct task_struct *p, |
96f874e2 | 1810 | const struct cpumask *new_mask) |
73fe6aae | 1811 | { |
8d3d5ada KT |
1812 | struct rq *rq; |
1813 | int weight; | |
73fe6aae GH |
1814 | |
1815 | BUG_ON(!rt_task(p)); | |
1816 | ||
8d3d5ada KT |
1817 | if (!p->on_rq) |
1818 | return; | |
917b627d | 1819 | |
8d3d5ada | 1820 | weight = cpumask_weight(new_mask); |
917b627d | 1821 | |
8d3d5ada KT |
1822 | /* |
1823 | * Only update if the process changes its state from whether it | |
1824 | * can migrate or not. | |
1825 | */ | |
29baa747 | 1826 | if ((p->nr_cpus_allowed > 1) == (weight > 1)) |
8d3d5ada | 1827 | return; |
917b627d | 1828 | |
8d3d5ada | 1829 | rq = task_rq(p); |
73fe6aae | 1830 | |
8d3d5ada KT |
1831 | /* |
1832 | * The process used to be able to migrate OR it can now migrate | |
1833 | */ | |
1834 | if (weight <= 1) { | |
1835 | if (!task_current(rq, p)) | |
1836 | dequeue_pushable_task(rq, p); | |
1837 | BUG_ON(!rq->rt.rt_nr_migratory); | |
1838 | rq->rt.rt_nr_migratory--; | |
1839 | } else { | |
1840 | if (!task_current(rq, p)) | |
1841 | enqueue_pushable_task(rq, p); | |
1842 | rq->rt.rt_nr_migratory++; | |
73fe6aae | 1843 | } |
8d3d5ada KT |
1844 | |
1845 | update_rt_migration(&rq->rt); | |
73fe6aae | 1846 | } |
deeeccd4 | 1847 | |
bdd7c81b | 1848 | /* Assumes rq->lock is held */ |
1f11eb6a | 1849 | static void rq_online_rt(struct rq *rq) |
bdd7c81b IM |
1850 | { |
1851 | if (rq->rt.overloaded) | |
1852 | rt_set_overload(rq); | |
6e0534f2 | 1853 | |
7def2be1 PZ |
1854 | __enable_runtime(rq); |
1855 | ||
e864c499 | 1856 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
bdd7c81b IM |
1857 | } |
1858 | ||
1859 | /* Assumes rq->lock is held */ | |
1f11eb6a | 1860 | static void rq_offline_rt(struct rq *rq) |
bdd7c81b IM |
1861 | { |
1862 | if (rq->rt.overloaded) | |
1863 | rt_clear_overload(rq); | |
6e0534f2 | 1864 | |
7def2be1 PZ |
1865 | __disable_runtime(rq); |
1866 | ||
6e0534f2 | 1867 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
bdd7c81b | 1868 | } |
cb469845 SR |
1869 | |
1870 | /* | |
1871 | * When switch from the rt queue, we bring ourselves to a position | |
1872 | * that we might want to pull RT tasks from other runqueues. | |
1873 | */ | |
da7a735e | 1874 | static void switched_from_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
1875 | { |
1876 | /* | |
1877 | * If there are other RT tasks then we will reschedule | |
1878 | * and the scheduling of the other RT tasks will handle | |
1879 | * the balancing. But if we are the last RT task | |
1880 | * we may need to handle the pulling of RT tasks | |
1881 | * now. | |
1882 | */ | |
fd2f4419 | 1883 | if (p->on_rq && !rq->rt.rt_nr_running) |
cb469845 SR |
1884 | pull_rt_task(rq); |
1885 | } | |
3d8cbdf8 | 1886 | |
029632fb | 1887 | void init_sched_rt_class(void) |
3d8cbdf8 RR |
1888 | { |
1889 | unsigned int i; | |
1890 | ||
029632fb | 1891 | for_each_possible_cpu(i) { |
eaa95840 | 1892 | zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
6ca09dfc | 1893 | GFP_KERNEL, cpu_to_node(i)); |
029632fb | 1894 | } |
3d8cbdf8 | 1895 | } |
cb469845 SR |
1896 | #endif /* CONFIG_SMP */ |
1897 | ||
1898 | /* | |
1899 | * When switching a task to RT, we may overload the runqueue | |
1900 | * with RT tasks. In this case we try to push them off to | |
1901 | * other runqueues. | |
1902 | */ | |
da7a735e | 1903 | static void switched_to_rt(struct rq *rq, struct task_struct *p) |
cb469845 SR |
1904 | { |
1905 | int check_resched = 1; | |
1906 | ||
1907 | /* | |
1908 | * If we are already running, then there's nothing | |
1909 | * that needs to be done. But if we are not running | |
1910 | * we may need to preempt the current running task. | |
1911 | * If that current running task is also an RT task | |
1912 | * then see if we can move to another run queue. | |
1913 | */ | |
fd2f4419 | 1914 | if (p->on_rq && rq->curr != p) { |
cb469845 SR |
1915 | #ifdef CONFIG_SMP |
1916 | if (rq->rt.overloaded && push_rt_task(rq) && | |
1917 | /* Don't resched if we changed runqueues */ | |
1918 | rq != task_rq(p)) | |
1919 | check_resched = 0; | |
1920 | #endif /* CONFIG_SMP */ | |
1921 | if (check_resched && p->prio < rq->curr->prio) | |
1922 | resched_task(rq->curr); | |
1923 | } | |
1924 | } | |
1925 | ||
1926 | /* | |
1927 | * Priority of the task has changed. This may cause | |
1928 | * us to initiate a push or pull. | |
1929 | */ | |
da7a735e PZ |
1930 | static void |
1931 | prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 1932 | { |
fd2f4419 | 1933 | if (!p->on_rq) |
da7a735e PZ |
1934 | return; |
1935 | ||
1936 | if (rq->curr == p) { | |
cb469845 SR |
1937 | #ifdef CONFIG_SMP |
1938 | /* | |
1939 | * If our priority decreases while running, we | |
1940 | * may need to pull tasks to this runqueue. | |
1941 | */ | |
1942 | if (oldprio < p->prio) | |
1943 | pull_rt_task(rq); | |
1944 | /* | |
1945 | * If there's a higher priority task waiting to run | |
6fa46fa5 SR |
1946 | * then reschedule. Note, the above pull_rt_task |
1947 | * can release the rq lock and p could migrate. | |
1948 | * Only reschedule if p is still on the same runqueue. | |
cb469845 | 1949 | */ |
e864c499 | 1950 | if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) |
cb469845 SR |
1951 | resched_task(p); |
1952 | #else | |
1953 | /* For UP simply resched on drop of prio */ | |
1954 | if (oldprio < p->prio) | |
1955 | resched_task(p); | |
e8fa1362 | 1956 | #endif /* CONFIG_SMP */ |
cb469845 SR |
1957 | } else { |
1958 | /* | |
1959 | * This task is not running, but if it is | |
1960 | * greater than the current running task | |
1961 | * then reschedule. | |
1962 | */ | |
1963 | if (p->prio < rq->curr->prio) | |
1964 | resched_task(rq->curr); | |
1965 | } | |
1966 | } | |
1967 | ||
78f2c7db PZ |
1968 | static void watchdog(struct rq *rq, struct task_struct *p) |
1969 | { | |
1970 | unsigned long soft, hard; | |
1971 | ||
78d7d407 JS |
1972 | /* max may change after cur was read, this will be fixed next tick */ |
1973 | soft = task_rlimit(p, RLIMIT_RTTIME); | |
1974 | hard = task_rlimit_max(p, RLIMIT_RTTIME); | |
78f2c7db PZ |
1975 | |
1976 | if (soft != RLIM_INFINITY) { | |
1977 | unsigned long next; | |
1978 | ||
1979 | p->rt.timeout++; | |
1980 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); | |
5a52dd50 | 1981 | if (p->rt.timeout > next) |
f06febc9 | 1982 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
78f2c7db PZ |
1983 | } |
1984 | } | |
bb44e5d1 | 1985 | |
8f4d37ec | 1986 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
bb44e5d1 | 1987 | { |
454c7999 CC |
1988 | struct sched_rt_entity *rt_se = &p->rt; |
1989 | ||
67e2be02 PZ |
1990 | update_curr_rt(rq); |
1991 | ||
78f2c7db PZ |
1992 | watchdog(rq, p); |
1993 | ||
bb44e5d1 IM |
1994 | /* |
1995 | * RR tasks need a special form of timeslice management. | |
1996 | * FIFO tasks have no timeslices. | |
1997 | */ | |
1998 | if (p->policy != SCHED_RR) | |
1999 | return; | |
2000 | ||
fa717060 | 2001 | if (--p->rt.time_slice) |
bb44e5d1 IM |
2002 | return; |
2003 | ||
de5bdff7 | 2004 | p->rt.time_slice = RR_TIMESLICE; |
bb44e5d1 | 2005 | |
98fbc798 | 2006 | /* |
454c7999 CC |
2007 | * Requeue to the end of queue if we (and all of our ancestors) are the |
2008 | * only element on the queue | |
98fbc798 | 2009 | */ |
454c7999 CC |
2010 | for_each_sched_rt_entity(rt_se) { |
2011 | if (rt_se->run_list.prev != rt_se->run_list.next) { | |
2012 | requeue_task_rt(rq, p, 0); | |
2013 | set_tsk_need_resched(p); | |
2014 | return; | |
2015 | } | |
98fbc798 | 2016 | } |
bb44e5d1 IM |
2017 | } |
2018 | ||
83b699ed SV |
2019 | static void set_curr_task_rt(struct rq *rq) |
2020 | { | |
2021 | struct task_struct *p = rq->curr; | |
2022 | ||
305e6835 | 2023 | p->se.exec_start = rq->clock_task; |
917b627d GH |
2024 | |
2025 | /* The running task is never eligible for pushing */ | |
2026 | dequeue_pushable_task(rq, p); | |
83b699ed SV |
2027 | } |
2028 | ||
6d686f45 | 2029 | static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) |
0d721cea PW |
2030 | { |
2031 | /* | |
2032 | * Time slice is 0 for SCHED_FIFO tasks | |
2033 | */ | |
2034 | if (task->policy == SCHED_RR) | |
de5bdff7 | 2035 | return RR_TIMESLICE; |
0d721cea PW |
2036 | else |
2037 | return 0; | |
2038 | } | |
2039 | ||
029632fb | 2040 | const struct sched_class rt_sched_class = { |
5522d5d5 | 2041 | .next = &fair_sched_class, |
bb44e5d1 IM |
2042 | .enqueue_task = enqueue_task_rt, |
2043 | .dequeue_task = dequeue_task_rt, | |
2044 | .yield_task = yield_task_rt, | |
2045 | ||
2046 | .check_preempt_curr = check_preempt_curr_rt, | |
2047 | ||
2048 | .pick_next_task = pick_next_task_rt, | |
2049 | .put_prev_task = put_prev_task_rt, | |
2050 | ||
681f3e68 | 2051 | #ifdef CONFIG_SMP |
4ce72a2c LZ |
2052 | .select_task_rq = select_task_rq_rt, |
2053 | ||
73fe6aae | 2054 | .set_cpus_allowed = set_cpus_allowed_rt, |
1f11eb6a GH |
2055 | .rq_online = rq_online_rt, |
2056 | .rq_offline = rq_offline_rt, | |
9a897c5a SR |
2057 | .pre_schedule = pre_schedule_rt, |
2058 | .post_schedule = post_schedule_rt, | |
efbbd05a | 2059 | .task_woken = task_woken_rt, |
cb469845 | 2060 | .switched_from = switched_from_rt, |
681f3e68 | 2061 | #endif |
bb44e5d1 | 2062 | |
83b699ed | 2063 | .set_curr_task = set_curr_task_rt, |
bb44e5d1 | 2064 | .task_tick = task_tick_rt, |
cb469845 | 2065 | |
0d721cea PW |
2066 | .get_rr_interval = get_rr_interval_rt, |
2067 | ||
cb469845 SR |
2068 | .prio_changed = prio_changed_rt, |
2069 | .switched_to = switched_to_rt, | |
bb44e5d1 | 2070 | }; |
ada18de2 PZ |
2071 | |
2072 | #ifdef CONFIG_SCHED_DEBUG | |
2073 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); | |
2074 | ||
029632fb | 2075 | void print_rt_stats(struct seq_file *m, int cpu) |
ada18de2 | 2076 | { |
ec514c48 | 2077 | rt_rq_iter_t iter; |
ada18de2 PZ |
2078 | struct rt_rq *rt_rq; |
2079 | ||
2080 | rcu_read_lock(); | |
ec514c48 | 2081 | for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) |
ada18de2 PZ |
2082 | print_rt_rq(m, cpu, rt_rq); |
2083 | rcu_read_unlock(); | |
2084 | } | |
55e12e5e | 2085 | #endif /* CONFIG_SCHED_DEBUG */ |