blob: 46167899d852bfe890404752a9d13a24ee099434 [file] [log] [blame]
Dario Faggioliaab03e02013-11-28 11:14:43 +01001/*
2 * Deadline Scheduling Class (SCHED_DEADLINE)
3 *
4 * Earliest Deadline First (EDF) + Constant Bandwidth Server (CBS).
5 *
6 * Tasks that periodically executes their instances for less than their
7 * runtime won't miss any of their deadlines.
8 * Tasks that are not periodic or sporadic or that tries to execute more
9 * than their reserved bandwidth will be slowed down (and may potentially
10 * miss some of their deadlines), and won't affect any other task.
11 *
12 * Copyright (C) 2012 Dario Faggioli <raistlin@linux.it>,
Juri Lelli1baca4c2013-11-07 14:43:38 +010013 * Juri Lelli <juri.lelli@gmail.com>,
Dario Faggioliaab03e02013-11-28 11:14:43 +010014 * Michael Trimarchi <michael@amarulasolutions.com>,
15 * Fabio Checconi <fchecconi@gmail.com>
16 */
17#include "sched.h"
18
Juri Lelli6bfd6d72013-11-07 14:43:47 +010019#include <linux/slab.h>
20
Dario Faggioli332ac172013-11-07 14:43:45 +010021struct dl_bandwidth def_dl_bandwidth;
22
Dario Faggioliaab03e02013-11-28 11:14:43 +010023static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
24{
25 return container_of(dl_se, struct task_struct, dl);
26}
27
28static inline struct rq *rq_of_dl_rq(struct dl_rq *dl_rq)
29{
30 return container_of(dl_rq, struct rq, dl);
31}
32
33static inline struct dl_rq *dl_rq_of_se(struct sched_dl_entity *dl_se)
34{
35 struct task_struct *p = dl_task_of(dl_se);
36 struct rq *rq = task_rq(p);
37
38 return &rq->dl;
39}
40
41static inline int on_dl_rq(struct sched_dl_entity *dl_se)
42{
43 return !RB_EMPTY_NODE(&dl_se->rb_node);
44}
45
46static inline int is_leftmost(struct task_struct *p, struct dl_rq *dl_rq)
47{
48 struct sched_dl_entity *dl_se = &p->dl;
49
50 return dl_rq->rb_leftmost == &dl_se->rb_node;
51}
52
Dario Faggioli332ac172013-11-07 14:43:45 +010053void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime)
54{
55 raw_spin_lock_init(&dl_b->dl_runtime_lock);
56 dl_b->dl_period = period;
57 dl_b->dl_runtime = runtime;
58}
59
Dario Faggioli332ac172013-11-07 14:43:45 +010060void init_dl_bw(struct dl_bw *dl_b)
61{
62 raw_spin_lock_init(&dl_b->lock);
63 raw_spin_lock(&def_dl_bandwidth.dl_runtime_lock);
Peter Zijlstra17248132013-12-17 12:44:49 +010064 if (global_rt_runtime() == RUNTIME_INF)
Dario Faggioli332ac172013-11-07 14:43:45 +010065 dl_b->bw = -1;
66 else
Peter Zijlstra17248132013-12-17 12:44:49 +010067 dl_b->bw = to_ratio(global_rt_period(), global_rt_runtime());
Dario Faggioli332ac172013-11-07 14:43:45 +010068 raw_spin_unlock(&def_dl_bandwidth.dl_runtime_lock);
69 dl_b->total_bw = 0;
70}
71
Dario Faggioliaab03e02013-11-28 11:14:43 +010072void init_dl_rq(struct dl_rq *dl_rq, struct rq *rq)
73{
74 dl_rq->rb_root = RB_ROOT;
Juri Lelli1baca4c2013-11-07 14:43:38 +010075
76#ifdef CONFIG_SMP
77 /* zero means no -deadline tasks */
78 dl_rq->earliest_dl.curr = dl_rq->earliest_dl.next = 0;
79
80 dl_rq->dl_nr_migratory = 0;
81 dl_rq->overloaded = 0;
82 dl_rq->pushable_dl_tasks_root = RB_ROOT;
Dario Faggioli332ac172013-11-07 14:43:45 +010083#else
84 init_dl_bw(&dl_rq->dl_bw);
Juri Lelli1baca4c2013-11-07 14:43:38 +010085#endif
Dario Faggioliaab03e02013-11-28 11:14:43 +010086}
87
Juri Lelli1baca4c2013-11-07 14:43:38 +010088#ifdef CONFIG_SMP
89
90static inline int dl_overloaded(struct rq *rq)
91{
92 return atomic_read(&rq->rd->dlo_count);
93}
94
95static inline void dl_set_overload(struct rq *rq)
96{
97 if (!rq->online)
98 return;
99
100 cpumask_set_cpu(rq->cpu, rq->rd->dlo_mask);
101 /*
102 * Must be visible before the overload count is
103 * set (as in sched_rt.c).
104 *
105 * Matched by the barrier in pull_dl_task().
106 */
107 smp_wmb();
108 atomic_inc(&rq->rd->dlo_count);
109}
110
111static inline void dl_clear_overload(struct rq *rq)
112{
113 if (!rq->online)
114 return;
115
116 atomic_dec(&rq->rd->dlo_count);
117 cpumask_clear_cpu(rq->cpu, rq->rd->dlo_mask);
118}
119
120static void update_dl_migration(struct dl_rq *dl_rq)
121{
Kirill Tkhai995b9ea2014-02-18 02:24:13 +0400122 if (dl_rq->dl_nr_migratory && dl_rq->dl_nr_running > 1) {
Juri Lelli1baca4c2013-11-07 14:43:38 +0100123 if (!dl_rq->overloaded) {
124 dl_set_overload(rq_of_dl_rq(dl_rq));
125 dl_rq->overloaded = 1;
126 }
127 } else if (dl_rq->overloaded) {
128 dl_clear_overload(rq_of_dl_rq(dl_rq));
129 dl_rq->overloaded = 0;
130 }
131}
132
133static void inc_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
134{
135 struct task_struct *p = dl_task_of(dl_se);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100136
Juri Lelli1baca4c2013-11-07 14:43:38 +0100137 if (p->nr_cpus_allowed > 1)
138 dl_rq->dl_nr_migratory++;
139
140 update_dl_migration(dl_rq);
141}
142
143static void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
144{
145 struct task_struct *p = dl_task_of(dl_se);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100146
Juri Lelli1baca4c2013-11-07 14:43:38 +0100147 if (p->nr_cpus_allowed > 1)
148 dl_rq->dl_nr_migratory--;
149
150 update_dl_migration(dl_rq);
151}
152
153/*
154 * The list of pushable -deadline task is not a plist, like in
155 * sched_rt.c, it is an rb-tree with tasks ordered by deadline.
156 */
157static void enqueue_pushable_dl_task(struct rq *rq, struct task_struct *p)
158{
159 struct dl_rq *dl_rq = &rq->dl;
160 struct rb_node **link = &dl_rq->pushable_dl_tasks_root.rb_node;
161 struct rb_node *parent = NULL;
162 struct task_struct *entry;
163 int leftmost = 1;
164
165 BUG_ON(!RB_EMPTY_NODE(&p->pushable_dl_tasks));
166
167 while (*link) {
168 parent = *link;
169 entry = rb_entry(parent, struct task_struct,
170 pushable_dl_tasks);
171 if (dl_entity_preempt(&p->dl, &entry->dl))
172 link = &parent->rb_left;
173 else {
174 link = &parent->rb_right;
175 leftmost = 0;
176 }
177 }
178
179 if (leftmost)
180 dl_rq->pushable_dl_tasks_leftmost = &p->pushable_dl_tasks;
181
182 rb_link_node(&p->pushable_dl_tasks, parent, link);
183 rb_insert_color(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root);
184}
185
186static void dequeue_pushable_dl_task(struct rq *rq, struct task_struct *p)
187{
188 struct dl_rq *dl_rq = &rq->dl;
189
190 if (RB_EMPTY_NODE(&p->pushable_dl_tasks))
191 return;
192
193 if (dl_rq->pushable_dl_tasks_leftmost == &p->pushable_dl_tasks) {
194 struct rb_node *next_node;
195
196 next_node = rb_next(&p->pushable_dl_tasks);
197 dl_rq->pushable_dl_tasks_leftmost = next_node;
198 }
199
200 rb_erase(&p->pushable_dl_tasks, &dl_rq->pushable_dl_tasks_root);
201 RB_CLEAR_NODE(&p->pushable_dl_tasks);
202}
203
204static inline int has_pushable_dl_tasks(struct rq *rq)
205{
206 return !RB_EMPTY_ROOT(&rq->dl.pushable_dl_tasks_root);
207}
208
209static int push_dl_task(struct rq *rq);
210
Peter Zijlstradc877342014-02-12 15:47:29 +0100211static inline bool need_pull_dl_task(struct rq *rq, struct task_struct *prev)
212{
213 return dl_task(prev);
214}
215
216static inline void set_post_schedule(struct rq *rq)
217{
218 rq->post_schedule = has_pushable_dl_tasks(rq);
219}
220
Juri Lelli1baca4c2013-11-07 14:43:38 +0100221#else
222
223static inline
224void enqueue_pushable_dl_task(struct rq *rq, struct task_struct *p)
225{
226}
227
228static inline
229void dequeue_pushable_dl_task(struct rq *rq, struct task_struct *p)
230{
231}
232
233static inline
234void inc_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
235{
236}
237
238static inline
239void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
240{
241}
242
Peter Zijlstradc877342014-02-12 15:47:29 +0100243static inline bool need_pull_dl_task(struct rq *rq, struct task_struct *prev)
244{
245 return false;
246}
247
248static inline int pull_dl_task(struct rq *rq)
249{
250 return 0;
251}
252
253static inline void set_post_schedule(struct rq *rq)
254{
255}
Juri Lelli1baca4c2013-11-07 14:43:38 +0100256#endif /* CONFIG_SMP */
257
Dario Faggioliaab03e02013-11-28 11:14:43 +0100258static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags);
259static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags);
260static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p,
261 int flags);
262
263/*
264 * We are being explicitly informed that a new instance is starting,
265 * and this means that:
266 * - the absolute deadline of the entity has to be placed at
267 * current time + relative deadline;
268 * - the runtime of the entity has to be set to the maximum value.
269 *
270 * The capability of specifying such event is useful whenever a -deadline
271 * entity wants to (try to!) synchronize its behaviour with the scheduler's
272 * one, and to (try to!) reconcile itself with its own scheduling
273 * parameters.
274 */
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100275static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se,
276 struct sched_dl_entity *pi_se)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100277{
278 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
279 struct rq *rq = rq_of_dl_rq(dl_rq);
280
281 WARN_ON(!dl_se->dl_new || dl_se->dl_throttled);
282
283 /*
284 * We use the regular wall clock time to set deadlines in the
285 * future; in fact, we must consider execution overheads (time
286 * spent on hardirq context, etc.).
287 */
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100288 dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
289 dl_se->runtime = pi_se->dl_runtime;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100290 dl_se->dl_new = 0;
291}
292
293/*
294 * Pure Earliest Deadline First (EDF) scheduling does not deal with the
295 * possibility of a entity lasting more than what it declared, and thus
296 * exhausting its runtime.
297 *
298 * Here we are interested in making runtime overrun possible, but we do
299 * not want a entity which is misbehaving to affect the scheduling of all
300 * other entities.
301 * Therefore, a budgeting strategy called Constant Bandwidth Server (CBS)
302 * is used, in order to confine each entity within its own bandwidth.
303 *
304 * This function deals exactly with that, and ensures that when the runtime
305 * of a entity is replenished, its deadline is also postponed. That ensures
306 * the overrunning entity can't interfere with other entity in the system and
307 * can't make them miss their deadlines. Reasons why this kind of overruns
308 * could happen are, typically, a entity voluntarily trying to overcome its
xiaofeng.yan1b09d292014-07-07 05:59:04 +0000309 * runtime, or it just underestimated it during sched_setattr().
Dario Faggioliaab03e02013-11-28 11:14:43 +0100310 */
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100311static void replenish_dl_entity(struct sched_dl_entity *dl_se,
312 struct sched_dl_entity *pi_se)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100313{
314 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
315 struct rq *rq = rq_of_dl_rq(dl_rq);
316
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100317 BUG_ON(pi_se->dl_runtime <= 0);
318
319 /*
320 * This could be the case for a !-dl task that is boosted.
321 * Just go with full inherited parameters.
322 */
323 if (dl_se->dl_deadline == 0) {
324 dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
325 dl_se->runtime = pi_se->dl_runtime;
326 }
327
Dario Faggioliaab03e02013-11-28 11:14:43 +0100328 /*
329 * We keep moving the deadline away until we get some
330 * available runtime for the entity. This ensures correct
331 * handling of situations where the runtime overrun is
332 * arbitrary large.
333 */
334 while (dl_se->runtime <= 0) {
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100335 dl_se->deadline += pi_se->dl_period;
336 dl_se->runtime += pi_se->dl_runtime;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100337 }
338
339 /*
340 * At this point, the deadline really should be "in
341 * the future" with respect to rq->clock. If it's
342 * not, we are, for some reason, lagging too much!
343 * Anyway, after having warn userspace abut that,
344 * we still try to keep the things running by
345 * resetting the deadline and the budget of the
346 * entity.
347 */
348 if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
John Stultzc2248152014-06-04 16:11:41 -0700349 printk_deferred_once("sched: DL replenish lagged to much\n");
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100350 dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
351 dl_se->runtime = pi_se->dl_runtime;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100352 }
353}
354
355/*
356 * Here we check if --at time t-- an entity (which is probably being
357 * [re]activated or, in general, enqueued) can use its remaining runtime
358 * and its current deadline _without_ exceeding the bandwidth it is
359 * assigned (function returns true if it can't). We are in fact applying
360 * one of the CBS rules: when a task wakes up, if the residual runtime
361 * over residual deadline fits within the allocated bandwidth, then we
362 * can keep the current (absolute) deadline and residual budget without
363 * disrupting the schedulability of the system. Otherwise, we should
364 * refill the runtime and set the deadline a period in the future,
365 * because keeping the current (absolute) deadline of the task would
Dario Faggioli712e5e32014-01-27 12:20:15 +0100366 * result in breaking guarantees promised to other tasks (refer to
367 * Documentation/scheduler/sched-deadline.txt for more informations).
Dario Faggioliaab03e02013-11-28 11:14:43 +0100368 *
369 * This function returns true if:
370 *
Harald Gustafsson755378a2013-11-07 14:43:40 +0100371 * runtime / (deadline - t) > dl_runtime / dl_period ,
Dario Faggioliaab03e02013-11-28 11:14:43 +0100372 *
373 * IOW we can't recycle current parameters.
Harald Gustafsson755378a2013-11-07 14:43:40 +0100374 *
375 * Notice that the bandwidth check is done against the period. For
376 * task with deadline equal to period this is the same of using
377 * dl_deadline instead of dl_period in the equation above.
Dario Faggioliaab03e02013-11-28 11:14:43 +0100378 */
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100379static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
380 struct sched_dl_entity *pi_se, u64 t)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100381{
382 u64 left, right;
383
384 /*
385 * left and right are the two sides of the equation above,
386 * after a bit of shuffling to use multiplications instead
387 * of divisions.
388 *
389 * Note that none of the time values involved in the two
390 * multiplications are absolute: dl_deadline and dl_runtime
391 * are the relative deadline and the maximum runtime of each
392 * instance, runtime is the runtime left for the last instance
393 * and (deadline - t), since t is rq->clock, is the time left
394 * to the (absolute) deadline. Even if overflowing the u64 type
395 * is very unlikely to occur in both cases, here we scale down
396 * as we want to avoid that risk at all. Scaling down by 10
397 * means that we reduce granularity to 1us. We are fine with it,
398 * since this is only a true/false check and, anyway, thinking
399 * of anything below microseconds resolution is actually fiction
400 * (but still we want to give the user that illusion >;).
401 */
Dario Faggioli332ac172013-11-07 14:43:45 +0100402 left = (pi_se->dl_period >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
403 right = ((dl_se->deadline - t) >> DL_SCALE) *
404 (pi_se->dl_runtime >> DL_SCALE);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100405
406 return dl_time_before(right, left);
407}
408
409/*
410 * When a -deadline entity is queued back on the runqueue, its runtime and
411 * deadline might need updating.
412 *
413 * The policy here is that we update the deadline of the entity only if:
414 * - the current deadline is in the past,
415 * - using the remaining runtime with the current deadline would make
416 * the entity exceed its bandwidth.
417 */
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100418static void update_dl_entity(struct sched_dl_entity *dl_se,
419 struct sched_dl_entity *pi_se)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100420{
421 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
422 struct rq *rq = rq_of_dl_rq(dl_rq);
423
424 /*
425 * The arrival of a new instance needs special treatment, i.e.,
426 * the actual scheduling parameters have to be "renewed".
427 */
428 if (dl_se->dl_new) {
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100429 setup_new_dl_entity(dl_se, pi_se);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100430 return;
431 }
432
433 if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100434 dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
435 dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
436 dl_se->runtime = pi_se->dl_runtime;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100437 }
438}
439
440/*
441 * If the entity depleted all its runtime, and if we want it to sleep
442 * while waiting for some new execution time to become available, we
443 * set the bandwidth enforcement timer to the replenishment instant
444 * and try to activate it.
445 *
446 * Notice that it is important for the caller to know if the timer
447 * actually started or not (i.e., the replenishment instant is in
448 * the future or in the past).
449 */
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100450static int start_dl_timer(struct sched_dl_entity *dl_se, bool boosted)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100451{
452 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
453 struct rq *rq = rq_of_dl_rq(dl_rq);
454 ktime_t now, act;
455 ktime_t soft, hard;
456 unsigned long range;
457 s64 delta;
458
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100459 if (boosted)
460 return 0;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100461 /*
462 * We want the timer to fire at the deadline, but considering
463 * that it is actually coming from rq->clock and not from
464 * hrtimer's time base reading.
465 */
466 act = ns_to_ktime(dl_se->deadline);
467 now = hrtimer_cb_get_time(&dl_se->dl_timer);
468 delta = ktime_to_ns(now) - rq_clock(rq);
469 act = ktime_add_ns(act, delta);
470
471 /*
472 * If the expiry time already passed, e.g., because the value
473 * chosen as the deadline is too small, don't even try to
474 * start the timer in the past!
475 */
476 if (ktime_us_delta(act, now) < 0)
477 return 0;
478
479 hrtimer_set_expires(&dl_se->dl_timer, act);
480
481 soft = hrtimer_get_softexpires(&dl_se->dl_timer);
482 hard = hrtimer_get_expires(&dl_se->dl_timer);
483 range = ktime_to_ns(ktime_sub(hard, soft));
484 __hrtimer_start_range_ns(&dl_se->dl_timer, soft,
485 range, HRTIMER_MODE_ABS, 0);
486
487 return hrtimer_active(&dl_se->dl_timer);
488}
489
490/*
491 * This is the bandwidth enforcement timer callback. If here, we know
492 * a task is not on its dl_rq, since the fact that the timer was running
493 * means the task is throttled and needs a runtime replenishment.
494 *
495 * However, what we actually do depends on the fact the task is active,
496 * (it is on its rq) or has been removed from there by a call to
497 * dequeue_task_dl(). In the former case we must issue the runtime
498 * replenishment and add the task back to the dl_rq; in the latter, we just
499 * do nothing but clearing dl_throttled, so that runtime and deadline
500 * updating (and the queueing back to dl_rq) will be done by the
501 * next call to enqueue_task_dl().
502 */
503static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
504{
505 struct sched_dl_entity *dl_se = container_of(timer,
506 struct sched_dl_entity,
507 dl_timer);
508 struct task_struct *p = dl_task_of(dl_se);
Kirill Tkhai0f397f22014-05-20 13:33:42 +0400509 struct rq *rq;
510again:
511 rq = task_rq(p);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100512 raw_spin_lock(&rq->lock);
513
Kirill Tkhai0f397f22014-05-20 13:33:42 +0400514 if (rq != task_rq(p)) {
515 /* Task was moved, retrying. */
516 raw_spin_unlock(&rq->lock);
517 goto again;
518 }
519
Dario Faggioliaab03e02013-11-28 11:14:43 +0100520 /*
Juri Lelliaee38ea2014-10-24 10:16:38 +0100521 * We need to take care of several possible races here:
522 *
523 * - the task might have changed its scheduling policy
524 * to something different than SCHED_DEADLINE
525 * - the task might have changed its reservation parameters
526 * (through sched_setattr())
527 * - the task might have been boosted by someone else and
528 * might be in the boosting/deboosting path
529 *
530 * In all this cases we bail out, as the task is already
531 * in the runqueue or is going to be enqueued back anyway.
Dario Faggioliaab03e02013-11-28 11:14:43 +0100532 */
Juri Lelliaee38ea2014-10-24 10:16:38 +0100533 if (!dl_task(p) || dl_se->dl_new ||
534 dl_se->dl_boosted || !dl_se->dl_throttled)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100535 goto unlock;
536
537 sched_clock_tick();
538 update_rq_clock(rq);
539 dl_se->dl_throttled = 0;
Juri Lelli5bfd1262014-04-15 13:49:04 +0200540 dl_se->dl_yielded = 0;
Kirill Tkhaida0c1e62014-08-20 13:47:32 +0400541 if (task_on_rq_queued(p)) {
Dario Faggioliaab03e02013-11-28 11:14:43 +0100542 enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
543 if (task_has_dl_policy(rq->curr))
544 check_preempt_curr_dl(rq, p, 0);
545 else
Kirill Tkhai88751252014-06-29 00:03:57 +0400546 resched_curr(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100547#ifdef CONFIG_SMP
548 /*
549 * Queueing this task back might have overloaded rq,
550 * check if we need to kick someone away.
551 */
552 if (has_pushable_dl_tasks(rq))
553 push_dl_task(rq);
554#endif
Dario Faggioliaab03e02013-11-28 11:14:43 +0100555 }
556unlock:
557 raw_spin_unlock(&rq->lock);
558
559 return HRTIMER_NORESTART;
560}
561
562void init_dl_task_timer(struct sched_dl_entity *dl_se)
563{
564 struct hrtimer *timer = &dl_se->dl_timer;
565
566 if (hrtimer_active(timer)) {
567 hrtimer_try_to_cancel(timer);
568 return;
569 }
570
571 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
572 timer->function = dl_task_timer;
573}
574
575static
576int dl_runtime_exceeded(struct rq *rq, struct sched_dl_entity *dl_se)
577{
578 int dmiss = dl_time_before(dl_se->deadline, rq_clock(rq));
579 int rorun = dl_se->runtime <= 0;
580
581 if (!rorun && !dmiss)
582 return 0;
583
584 /*
585 * If we are beyond our current deadline and we are still
586 * executing, then we have already used some of the runtime of
587 * the next instance. Thus, if we do not account that, we are
588 * stealing bandwidth from the system at each deadline miss!
589 */
590 if (dmiss) {
591 dl_se->runtime = rorun ? dl_se->runtime : 0;
592 dl_se->runtime -= rq_clock(rq) - dl_se->deadline;
593 }
594
595 return 1;
596}
597
Juri Lellifaa59932014-02-21 11:37:15 +0100598extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
599
Dario Faggioliaab03e02013-11-28 11:14:43 +0100600/*
601 * Update the current task's runtime statistics (provided it is still
602 * a -deadline task and has not been removed from the dl_rq).
603 */
604static void update_curr_dl(struct rq *rq)
605{
606 struct task_struct *curr = rq->curr;
607 struct sched_dl_entity *dl_se = &curr->dl;
608 u64 delta_exec;
609
610 if (!dl_task(curr) || !on_dl_rq(dl_se))
611 return;
612
613 /*
614 * Consumed budget is computed considering the time as
615 * observed by schedulable tasks (excluding time spent
616 * in hardirq context, etc.). Deadlines are instead
617 * computed using hard walltime. This seems to be the more
618 * natural solution, but the full ramifications of this
619 * approach need further study.
620 */
621 delta_exec = rq_clock_task(rq) - curr->se.exec_start;
Kirill Tkhai734ff2a2014-03-04 19:25:46 +0400622 if (unlikely((s64)delta_exec <= 0))
623 return;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100624
625 schedstat_set(curr->se.statistics.exec_max,
626 max(curr->se.statistics.exec_max, delta_exec));
627
628 curr->se.sum_exec_runtime += delta_exec;
629 account_group_exec_runtime(curr, delta_exec);
630
631 curr->se.exec_start = rq_clock_task(rq);
632 cpuacct_charge(curr, delta_exec);
633
Dario Faggioli239be4a2013-11-07 14:43:39 +0100634 sched_rt_avg_update(rq, delta_exec);
635
Dario Faggioliaab03e02013-11-28 11:14:43 +0100636 dl_se->runtime -= delta_exec;
637 if (dl_runtime_exceeded(rq, dl_se)) {
638 __dequeue_task_dl(rq, curr, 0);
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100639 if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted)))
Dario Faggioliaab03e02013-11-28 11:14:43 +0100640 dl_se->dl_throttled = 1;
641 else
642 enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH);
643
644 if (!is_leftmost(curr, &rq->dl))
Kirill Tkhai88751252014-06-29 00:03:57 +0400645 resched_curr(rq);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100646 }
Peter Zijlstra17248132013-12-17 12:44:49 +0100647
648 /*
649 * Because -- for now -- we share the rt bandwidth, we need to
650 * account our runtime there too, otherwise actual rt tasks
651 * would be able to exceed the shared quota.
652 *
653 * Account to the root rt group for now.
654 *
655 * The solution we're working towards is having the RT groups scheduled
656 * using deadline servers -- however there's a few nasties to figure
657 * out before that can happen.
658 */
659 if (rt_bandwidth_enabled()) {
660 struct rt_rq *rt_rq = &rq->rt;
661
662 raw_spin_lock(&rt_rq->rt_runtime_lock);
Peter Zijlstra17248132013-12-17 12:44:49 +0100663 /*
664 * We'll let actual RT tasks worry about the overflow here, we
Juri Lellifaa59932014-02-21 11:37:15 +0100665 * have our own CBS to keep us inline; only account when RT
666 * bandwidth is relevant.
Peter Zijlstra17248132013-12-17 12:44:49 +0100667 */
Juri Lellifaa59932014-02-21 11:37:15 +0100668 if (sched_rt_bandwidth_account(rt_rq))
669 rt_rq->rt_time += delta_exec;
Peter Zijlstra17248132013-12-17 12:44:49 +0100670 raw_spin_unlock(&rt_rq->rt_runtime_lock);
671 }
Dario Faggioliaab03e02013-11-28 11:14:43 +0100672}
673
Juri Lelli1baca4c2013-11-07 14:43:38 +0100674#ifdef CONFIG_SMP
675
676static struct task_struct *pick_next_earliest_dl_task(struct rq *rq, int cpu);
677
678static inline u64 next_deadline(struct rq *rq)
679{
680 struct task_struct *next = pick_next_earliest_dl_task(rq, rq->cpu);
681
682 if (next && dl_prio(next->prio))
683 return next->dl.deadline;
684 else
685 return 0;
686}
687
688static void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
689{
690 struct rq *rq = rq_of_dl_rq(dl_rq);
691
692 if (dl_rq->earliest_dl.curr == 0 ||
693 dl_time_before(deadline, dl_rq->earliest_dl.curr)) {
694 /*
695 * If the dl_rq had no -deadline tasks, or if the new task
696 * has shorter deadline than the current one on dl_rq, we
697 * know that the previous earliest becomes our next earliest,
698 * as the new task becomes the earliest itself.
699 */
700 dl_rq->earliest_dl.next = dl_rq->earliest_dl.curr;
701 dl_rq->earliest_dl.curr = deadline;
Juri Lelli6bfd6d72013-11-07 14:43:47 +0100702 cpudl_set(&rq->rd->cpudl, rq->cpu, deadline, 1);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100703 } else if (dl_rq->earliest_dl.next == 0 ||
704 dl_time_before(deadline, dl_rq->earliest_dl.next)) {
705 /*
706 * On the other hand, if the new -deadline task has a
707 * a later deadline than the earliest one on dl_rq, but
708 * it is earlier than the next (if any), we must
709 * recompute the next-earliest.
710 */
711 dl_rq->earliest_dl.next = next_deadline(rq);
712 }
713}
714
715static void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
716{
717 struct rq *rq = rq_of_dl_rq(dl_rq);
718
719 /*
720 * Since we may have removed our earliest (and/or next earliest)
721 * task we must recompute them.
722 */
723 if (!dl_rq->dl_nr_running) {
724 dl_rq->earliest_dl.curr = 0;
725 dl_rq->earliest_dl.next = 0;
Juri Lelli6bfd6d72013-11-07 14:43:47 +0100726 cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100727 } else {
728 struct rb_node *leftmost = dl_rq->rb_leftmost;
729 struct sched_dl_entity *entry;
730
731 entry = rb_entry(leftmost, struct sched_dl_entity, rb_node);
732 dl_rq->earliest_dl.curr = entry->deadline;
733 dl_rq->earliest_dl.next = next_deadline(rq);
Juri Lelli6bfd6d72013-11-07 14:43:47 +0100734 cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline, 1);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100735 }
736}
737
738#else
739
740static inline void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline) {}
741static inline void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline) {}
742
743#endif /* CONFIG_SMP */
744
745static inline
746void inc_dl_tasks(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
747{
748 int prio = dl_task_of(dl_se)->prio;
749 u64 deadline = dl_se->deadline;
750
751 WARN_ON(!dl_prio(prio));
752 dl_rq->dl_nr_running++;
Kirill Tkhai72465442014-05-09 03:00:14 +0400753 add_nr_running(rq_of_dl_rq(dl_rq), 1);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100754
755 inc_dl_deadline(dl_rq, deadline);
756 inc_dl_migration(dl_se, dl_rq);
757}
758
759static inline
760void dec_dl_tasks(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
761{
762 int prio = dl_task_of(dl_se)->prio;
763
764 WARN_ON(!dl_prio(prio));
765 WARN_ON(!dl_rq->dl_nr_running);
766 dl_rq->dl_nr_running--;
Kirill Tkhai72465442014-05-09 03:00:14 +0400767 sub_nr_running(rq_of_dl_rq(dl_rq), 1);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100768
769 dec_dl_deadline(dl_rq, dl_se->deadline);
770 dec_dl_migration(dl_se, dl_rq);
771}
772
Dario Faggioliaab03e02013-11-28 11:14:43 +0100773static void __enqueue_dl_entity(struct sched_dl_entity *dl_se)
774{
775 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
776 struct rb_node **link = &dl_rq->rb_root.rb_node;
777 struct rb_node *parent = NULL;
778 struct sched_dl_entity *entry;
779 int leftmost = 1;
780
781 BUG_ON(!RB_EMPTY_NODE(&dl_se->rb_node));
782
783 while (*link) {
784 parent = *link;
785 entry = rb_entry(parent, struct sched_dl_entity, rb_node);
786 if (dl_time_before(dl_se->deadline, entry->deadline))
787 link = &parent->rb_left;
788 else {
789 link = &parent->rb_right;
790 leftmost = 0;
791 }
792 }
793
794 if (leftmost)
795 dl_rq->rb_leftmost = &dl_se->rb_node;
796
797 rb_link_node(&dl_se->rb_node, parent, link);
798 rb_insert_color(&dl_se->rb_node, &dl_rq->rb_root);
799
Juri Lelli1baca4c2013-11-07 14:43:38 +0100800 inc_dl_tasks(dl_se, dl_rq);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100801}
802
803static void __dequeue_dl_entity(struct sched_dl_entity *dl_se)
804{
805 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
806
807 if (RB_EMPTY_NODE(&dl_se->rb_node))
808 return;
809
810 if (dl_rq->rb_leftmost == &dl_se->rb_node) {
811 struct rb_node *next_node;
812
813 next_node = rb_next(&dl_se->rb_node);
814 dl_rq->rb_leftmost = next_node;
815 }
816
817 rb_erase(&dl_se->rb_node, &dl_rq->rb_root);
818 RB_CLEAR_NODE(&dl_se->rb_node);
819
Juri Lelli1baca4c2013-11-07 14:43:38 +0100820 dec_dl_tasks(dl_se, dl_rq);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100821}
822
823static void
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100824enqueue_dl_entity(struct sched_dl_entity *dl_se,
825 struct sched_dl_entity *pi_se, int flags)
Dario Faggioliaab03e02013-11-28 11:14:43 +0100826{
827 BUG_ON(on_dl_rq(dl_se));
828
829 /*
830 * If this is a wakeup or a new instance, the scheduling
831 * parameters of the task might need updating. Otherwise,
832 * we want a replenishment of its runtime.
833 */
834 if (!dl_se->dl_new && flags & ENQUEUE_REPLENISH)
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100835 replenish_dl_entity(dl_se, pi_se);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100836 else
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100837 update_dl_entity(dl_se, pi_se);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100838
839 __enqueue_dl_entity(dl_se);
840}
841
842static void dequeue_dl_entity(struct sched_dl_entity *dl_se)
843{
844 __dequeue_dl_entity(dl_se);
845}
846
847static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
848{
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100849 struct task_struct *pi_task = rt_mutex_get_top_task(p);
850 struct sched_dl_entity *pi_se = &p->dl;
851
852 /*
853 * Use the scheduling parameters of the top pi-waiter
854 * task if we have one and its (relative) deadline is
855 * smaller than our one... OTW we keep our runtime and
856 * deadline.
857 */
Juri Lelli64be6f12014-10-24 10:16:37 +0100858 if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) {
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100859 pi_se = &pi_task->dl;
Juri Lelli64be6f12014-10-24 10:16:37 +0100860 } else if (!dl_prio(p->normal_prio)) {
861 /*
862 * Special case in which we have a !SCHED_DEADLINE task
863 * that is going to be deboosted, but exceedes its
864 * runtime while doing so. No point in replenishing
865 * it, as it's going to return back to its original
866 * scheduling class after this.
867 */
868 BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH);
869 return;
870 }
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100871
Dario Faggioliaab03e02013-11-28 11:14:43 +0100872 /*
873 * If p is throttled, we do nothing. In fact, if it exhausted
874 * its budget it needs a replenishment and, since it now is on
875 * its rq, the bandwidth timer callback (which clearly has not
876 * run yet) will take care of this.
877 */
878 if (p->dl.dl_throttled)
879 return;
880
Dario Faggioli2d3d8912013-11-07 14:43:44 +0100881 enqueue_dl_entity(&p->dl, pi_se, flags);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100882
883 if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
884 enqueue_pushable_dl_task(rq, p);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100885}
886
887static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags)
888{
889 dequeue_dl_entity(&p->dl);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100890 dequeue_pushable_dl_task(rq, p);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100891}
892
893static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags)
894{
895 update_curr_dl(rq);
896 __dequeue_task_dl(rq, p, flags);
Dario Faggioliaab03e02013-11-28 11:14:43 +0100897}
898
899/*
900 * Yield task semantic for -deadline tasks is:
901 *
902 * get off from the CPU until our next instance, with
903 * a new runtime. This is of little use now, since we
904 * don't have a bandwidth reclaiming mechanism. Anyway,
905 * bandwidth reclaiming is planned for the future, and
906 * yield_task_dl will indicate that some spare budget
907 * is available for other task instances to use it.
908 */
909static void yield_task_dl(struct rq *rq)
910{
911 struct task_struct *p = rq->curr;
912
913 /*
914 * We make the task go to sleep until its current deadline by
915 * forcing its runtime to zero. This way, update_curr_dl() stops
916 * it and the bandwidth timer will wake it up and will give it
Juri Lelli5bfd1262014-04-15 13:49:04 +0200917 * new scheduling parameters (thanks to dl_yielded=1).
Dario Faggioliaab03e02013-11-28 11:14:43 +0100918 */
919 if (p->dl.runtime > 0) {
Juri Lelli5bfd1262014-04-15 13:49:04 +0200920 rq->curr->dl.dl_yielded = 1;
Dario Faggioliaab03e02013-11-28 11:14:43 +0100921 p->dl.runtime = 0;
922 }
923 update_curr_dl(rq);
924}
925
Juri Lelli1baca4c2013-11-07 14:43:38 +0100926#ifdef CONFIG_SMP
927
928static int find_later_rq(struct task_struct *task);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100929
930static int
931select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
932{
933 struct task_struct *curr;
934 struct rq *rq;
935
936 if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
937 goto out;
938
939 rq = cpu_rq(cpu);
940
941 rcu_read_lock();
942 curr = ACCESS_ONCE(rq->curr); /* unlocked access */
943
944 /*
945 * If we are dealing with a -deadline task, we must
946 * decide where to wake it up.
947 * If it has a later deadline and the current task
948 * on this rq can't move (provided the waking task
949 * can!) we prefer to send it somewhere else. On the
950 * other hand, if it has a shorter deadline, we
951 * try to make it stay here, it might be important.
952 */
953 if (unlikely(dl_task(curr)) &&
954 (curr->nr_cpus_allowed < 2 ||
955 !dl_entity_preempt(&p->dl, &curr->dl)) &&
956 (p->nr_cpus_allowed > 1)) {
957 int target = find_later_rq(p);
958
959 if (target != -1)
960 cpu = target;
961 }
962 rcu_read_unlock();
963
964out:
965 return cpu;
966}
967
968static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
969{
970 /*
971 * Current can't be migrated, useless to reschedule,
972 * let's hope p can move out.
973 */
974 if (rq->curr->nr_cpus_allowed == 1 ||
Juri Lelli6bfd6d72013-11-07 14:43:47 +0100975 cpudl_find(&rq->rd->cpudl, rq->curr, NULL) == -1)
Juri Lelli1baca4c2013-11-07 14:43:38 +0100976 return;
977
978 /*
979 * p is migratable, so let's not schedule it and
980 * see if it is pushed or pulled somewhere else.
981 */
982 if (p->nr_cpus_allowed != 1 &&
Juri Lelli6bfd6d72013-11-07 14:43:47 +0100983 cpudl_find(&rq->rd->cpudl, p, NULL) != -1)
Juri Lelli1baca4c2013-11-07 14:43:38 +0100984 return;
985
Kirill Tkhai88751252014-06-29 00:03:57 +0400986 resched_curr(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +0100987}
988
Peter Zijlstra38033c32014-01-23 20:32:21 +0100989static int pull_dl_task(struct rq *this_rq);
990
Juri Lelli1baca4c2013-11-07 14:43:38 +0100991#endif /* CONFIG_SMP */
992
Dario Faggioliaab03e02013-11-28 11:14:43 +0100993/*
994 * Only called when both the current and waking task are -deadline
995 * tasks.
996 */
997static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p,
998 int flags)
999{
Juri Lelli1baca4c2013-11-07 14:43:38 +01001000 if (dl_entity_preempt(&p->dl, &rq->curr->dl)) {
Kirill Tkhai88751252014-06-29 00:03:57 +04001001 resched_curr(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001002 return;
1003 }
1004
1005#ifdef CONFIG_SMP
1006 /*
1007 * In the unlikely case current and p have the same deadline
1008 * let us try to decide what's the best thing to do...
1009 */
Dario Faggioli332ac172013-11-07 14:43:45 +01001010 if ((p->dl.deadline == rq->curr->dl.deadline) &&
1011 !test_tsk_need_resched(rq->curr))
Juri Lelli1baca4c2013-11-07 14:43:38 +01001012 check_preempt_equal_dl(rq, p);
1013#endif /* CONFIG_SMP */
Dario Faggioliaab03e02013-11-28 11:14:43 +01001014}
1015
1016#ifdef CONFIG_SCHED_HRTICK
1017static void start_hrtick_dl(struct rq *rq, struct task_struct *p)
1018{
xiaofeng.yan177ef2a2014-08-26 03:15:41 +00001019 hrtick_start(rq, p->dl.runtime);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001020}
1021#endif
1022
1023static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
1024 struct dl_rq *dl_rq)
1025{
1026 struct rb_node *left = dl_rq->rb_leftmost;
1027
1028 if (!left)
1029 return NULL;
1030
1031 return rb_entry(left, struct sched_dl_entity, rb_node);
1032}
1033
Peter Zijlstra606dba22012-02-11 06:05:00 +01001034struct task_struct *pick_next_task_dl(struct rq *rq, struct task_struct *prev)
Dario Faggioliaab03e02013-11-28 11:14:43 +01001035{
1036 struct sched_dl_entity *dl_se;
1037 struct task_struct *p;
1038 struct dl_rq *dl_rq;
1039
1040 dl_rq = &rq->dl;
1041
Kirill Tkhaia1d9a322014-04-10 17:38:36 +04001042 if (need_pull_dl_task(rq, prev)) {
Peter Zijlstra38033c32014-01-23 20:32:21 +01001043 pull_dl_task(rq);
Kirill Tkhaia1d9a322014-04-10 17:38:36 +04001044 /*
1045 * pull_rt_task() can drop (and re-acquire) rq->lock; this
1046 * means a stop task can slip in, in which case we need to
1047 * re-start task selection.
1048 */
Kirill Tkhaida0c1e62014-08-20 13:47:32 +04001049 if (rq->stop && task_on_rq_queued(rq->stop))
Kirill Tkhaia1d9a322014-04-10 17:38:36 +04001050 return RETRY_TASK;
1051 }
1052
Kirill Tkhai734ff2a2014-03-04 19:25:46 +04001053 /*
1054 * When prev is DL, we may throttle it in put_prev_task().
1055 * So, we update time before we check for dl_nr_running.
1056 */
1057 if (prev->sched_class == &dl_sched_class)
1058 update_curr_dl(rq);
Peter Zijlstra38033c32014-01-23 20:32:21 +01001059
Dario Faggioliaab03e02013-11-28 11:14:43 +01001060 if (unlikely(!dl_rq->dl_nr_running))
1061 return NULL;
1062
Peter Zijlstra3f1d2a32014-02-12 10:49:30 +01001063 put_prev_task(rq, prev);
Peter Zijlstra606dba22012-02-11 06:05:00 +01001064
Dario Faggioliaab03e02013-11-28 11:14:43 +01001065 dl_se = pick_next_dl_entity(rq, dl_rq);
1066 BUG_ON(!dl_se);
1067
1068 p = dl_task_of(dl_se);
1069 p->se.exec_start = rq_clock_task(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001070
1071 /* Running task will never be pushed. */
Juri Lelli71362652014-01-14 12:03:51 +01001072 dequeue_pushable_dl_task(rq, p);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001073
Dario Faggioliaab03e02013-11-28 11:14:43 +01001074#ifdef CONFIG_SCHED_HRTICK
1075 if (hrtick_enabled(rq))
1076 start_hrtick_dl(rq, p);
1077#endif
Juri Lelli1baca4c2013-11-07 14:43:38 +01001078
Peter Zijlstradc877342014-02-12 15:47:29 +01001079 set_post_schedule(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001080
Dario Faggioliaab03e02013-11-28 11:14:43 +01001081 return p;
1082}
1083
1084static void put_prev_task_dl(struct rq *rq, struct task_struct *p)
1085{
1086 update_curr_dl(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001087
1088 if (on_dl_rq(&p->dl) && p->nr_cpus_allowed > 1)
1089 enqueue_pushable_dl_task(rq, p);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001090}
1091
1092static void task_tick_dl(struct rq *rq, struct task_struct *p, int queued)
1093{
1094 update_curr_dl(rq);
1095
1096#ifdef CONFIG_SCHED_HRTICK
1097 if (hrtick_enabled(rq) && queued && p->dl.runtime > 0)
1098 start_hrtick_dl(rq, p);
1099#endif
1100}
1101
1102static void task_fork_dl(struct task_struct *p)
1103{
1104 /*
1105 * SCHED_DEADLINE tasks cannot fork and this is achieved through
1106 * sched_fork()
1107 */
1108}
1109
1110static void task_dead_dl(struct task_struct *p)
1111{
1112 struct hrtimer *timer = &p->dl.dl_timer;
Dario Faggioli332ac172013-11-07 14:43:45 +01001113 struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
1114
1115 /*
1116 * Since we are TASK_DEAD we won't slip out of the domain!
1117 */
1118 raw_spin_lock_irq(&dl_b->lock);
1119 dl_b->total_bw -= p->dl.dl_bw;
1120 raw_spin_unlock_irq(&dl_b->lock);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001121
Dario Faggioli2d3d8912013-11-07 14:43:44 +01001122 hrtimer_cancel(timer);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001123}
1124
1125static void set_curr_task_dl(struct rq *rq)
1126{
1127 struct task_struct *p = rq->curr;
1128
1129 p->se.exec_start = rq_clock_task(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001130
1131 /* You can't push away the running task */
1132 dequeue_pushable_dl_task(rq, p);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001133}
1134
Juri Lelli1baca4c2013-11-07 14:43:38 +01001135#ifdef CONFIG_SMP
1136
1137/* Only try algorithms three times */
1138#define DL_MAX_TRIES 3
1139
1140static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu)
1141{
1142 if (!task_running(rq, p) &&
Kirill Tkhai1ba93d42014-09-12 17:42:20 +04001143 cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
Juri Lelli1baca4c2013-11-07 14:43:38 +01001144 return 1;
Juri Lelli1baca4c2013-11-07 14:43:38 +01001145 return 0;
1146}
1147
1148/* Returns the second earliest -deadline task, NULL otherwise */
1149static struct task_struct *pick_next_earliest_dl_task(struct rq *rq, int cpu)
1150{
1151 struct rb_node *next_node = rq->dl.rb_leftmost;
1152 struct sched_dl_entity *dl_se;
1153 struct task_struct *p = NULL;
1154
1155next_node:
1156 next_node = rb_next(next_node);
1157 if (next_node) {
1158 dl_se = rb_entry(next_node, struct sched_dl_entity, rb_node);
1159 p = dl_task_of(dl_se);
1160
1161 if (pick_dl_task(rq, p, cpu))
1162 return p;
1163
1164 goto next_node;
1165 }
1166
1167 return NULL;
1168}
1169
Juri Lelli1baca4c2013-11-07 14:43:38 +01001170static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask_dl);
1171
1172static int find_later_rq(struct task_struct *task)
1173{
1174 struct sched_domain *sd;
Christoph Lameter4ba29682014-08-26 19:12:21 -05001175 struct cpumask *later_mask = this_cpu_cpumask_var_ptr(local_cpu_mask_dl);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001176 int this_cpu = smp_processor_id();
1177 int best_cpu, cpu = task_cpu(task);
1178
1179 /* Make sure the mask is initialized first */
1180 if (unlikely(!later_mask))
1181 return -1;
1182
1183 if (task->nr_cpus_allowed == 1)
1184 return -1;
1185
Juri Lelli91ec6772014-09-19 10:22:41 +01001186 /*
1187 * We have to consider system topology and task affinity
1188 * first, then we can look for a suitable cpu.
1189 */
1190 cpumask_copy(later_mask, task_rq(task)->rd->span);
1191 cpumask_and(later_mask, later_mask, cpu_active_mask);
1192 cpumask_and(later_mask, later_mask, &task->cpus_allowed);
Juri Lelli6bfd6d72013-11-07 14:43:47 +01001193 best_cpu = cpudl_find(&task_rq(task)->rd->cpudl,
1194 task, later_mask);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001195 if (best_cpu == -1)
1196 return -1;
1197
1198 /*
1199 * If we are here, some target has been found,
1200 * the most suitable of which is cached in best_cpu.
1201 * This is, among the runqueues where the current tasks
1202 * have later deadlines than the task's one, the rq
1203 * with the latest possible one.
1204 *
1205 * Now we check how well this matches with task's
1206 * affinity and system topology.
1207 *
1208 * The last cpu where the task run is our first
1209 * guess, since it is most likely cache-hot there.
1210 */
1211 if (cpumask_test_cpu(cpu, later_mask))
1212 return cpu;
1213 /*
1214 * Check if this_cpu is to be skipped (i.e., it is
1215 * not in the mask) or not.
1216 */
1217 if (!cpumask_test_cpu(this_cpu, later_mask))
1218 this_cpu = -1;
1219
1220 rcu_read_lock();
1221 for_each_domain(cpu, sd) {
1222 if (sd->flags & SD_WAKE_AFFINE) {
1223
1224 /*
1225 * If possible, preempting this_cpu is
1226 * cheaper than migrating.
1227 */
1228 if (this_cpu != -1 &&
1229 cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {
1230 rcu_read_unlock();
1231 return this_cpu;
1232 }
1233
1234 /*
1235 * Last chance: if best_cpu is valid and is
1236 * in the mask, that becomes our choice.
1237 */
1238 if (best_cpu < nr_cpu_ids &&
1239 cpumask_test_cpu(best_cpu, sched_domain_span(sd))) {
1240 rcu_read_unlock();
1241 return best_cpu;
1242 }
1243 }
1244 }
1245 rcu_read_unlock();
1246
1247 /*
1248 * At this point, all our guesses failed, we just return
1249 * 'something', and let the caller sort the things out.
1250 */
1251 if (this_cpu != -1)
1252 return this_cpu;
1253
1254 cpu = cpumask_any(later_mask);
1255 if (cpu < nr_cpu_ids)
1256 return cpu;
1257
1258 return -1;
1259}
1260
1261/* Locks the rq it finds */
1262static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq)
1263{
1264 struct rq *later_rq = NULL;
1265 int tries;
1266 int cpu;
1267
1268 for (tries = 0; tries < DL_MAX_TRIES; tries++) {
1269 cpu = find_later_rq(task);
1270
1271 if ((cpu == -1) || (cpu == rq->cpu))
1272 break;
1273
1274 later_rq = cpu_rq(cpu);
1275
1276 /* Retry if something changed. */
1277 if (double_lock_balance(rq, later_rq)) {
1278 if (unlikely(task_rq(task) != rq ||
1279 !cpumask_test_cpu(later_rq->cpu,
1280 &task->cpus_allowed) ||
Kirill Tkhaida0c1e62014-08-20 13:47:32 +04001281 task_running(rq, task) ||
1282 !task_on_rq_queued(task))) {
Juri Lelli1baca4c2013-11-07 14:43:38 +01001283 double_unlock_balance(rq, later_rq);
1284 later_rq = NULL;
1285 break;
1286 }
1287 }
1288
1289 /*
1290 * If the rq we found has no -deadline task, or
1291 * its earliest one has a later deadline than our
1292 * task, the rq is a good one.
1293 */
1294 if (!later_rq->dl.dl_nr_running ||
1295 dl_time_before(task->dl.deadline,
1296 later_rq->dl.earliest_dl.curr))
1297 break;
1298
1299 /* Otherwise we try again. */
1300 double_unlock_balance(rq, later_rq);
1301 later_rq = NULL;
1302 }
1303
1304 return later_rq;
1305}
1306
1307static struct task_struct *pick_next_pushable_dl_task(struct rq *rq)
1308{
1309 struct task_struct *p;
1310
1311 if (!has_pushable_dl_tasks(rq))
1312 return NULL;
1313
1314 p = rb_entry(rq->dl.pushable_dl_tasks_leftmost,
1315 struct task_struct, pushable_dl_tasks);
1316
1317 BUG_ON(rq->cpu != task_cpu(p));
1318 BUG_ON(task_current(rq, p));
1319 BUG_ON(p->nr_cpus_allowed <= 1);
1320
Kirill Tkhaida0c1e62014-08-20 13:47:32 +04001321 BUG_ON(!task_on_rq_queued(p));
Juri Lelli1baca4c2013-11-07 14:43:38 +01001322 BUG_ON(!dl_task(p));
1323
1324 return p;
1325}
1326
1327/*
1328 * See if the non running -deadline tasks on this rq
1329 * can be sent to some other CPU where they can preempt
1330 * and start executing.
1331 */
1332static int push_dl_task(struct rq *rq)
1333{
1334 struct task_struct *next_task;
1335 struct rq *later_rq;
1336
1337 if (!rq->dl.overloaded)
1338 return 0;
1339
1340 next_task = pick_next_pushable_dl_task(rq);
1341 if (!next_task)
1342 return 0;
1343
1344retry:
1345 if (unlikely(next_task == rq->curr)) {
1346 WARN_ON(1);
1347 return 0;
1348 }
1349
1350 /*
1351 * If next_task preempts rq->curr, and rq->curr
1352 * can move away, it makes sense to just reschedule
1353 * without going further in pushing next_task.
1354 */
1355 if (dl_task(rq->curr) &&
1356 dl_time_before(next_task->dl.deadline, rq->curr->dl.deadline) &&
1357 rq->curr->nr_cpus_allowed > 1) {
Kirill Tkhai88751252014-06-29 00:03:57 +04001358 resched_curr(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001359 return 0;
1360 }
1361
1362 /* We might release rq lock */
1363 get_task_struct(next_task);
1364
1365 /* Will lock the rq it'll find */
1366 later_rq = find_lock_later_rq(next_task, rq);
1367 if (!later_rq) {
1368 struct task_struct *task;
1369
1370 /*
1371 * We must check all this again, since
1372 * find_lock_later_rq releases rq->lock and it is
1373 * then possible that next_task has migrated.
1374 */
1375 task = pick_next_pushable_dl_task(rq);
1376 if (task_cpu(next_task) == rq->cpu && task == next_task) {
1377 /*
1378 * The task is still there. We don't try
1379 * again, some other cpu will pull it when ready.
1380 */
1381 dequeue_pushable_dl_task(rq, next_task);
1382 goto out;
1383 }
1384
1385 if (!task)
1386 /* No more tasks */
1387 goto out;
1388
1389 put_task_struct(next_task);
1390 next_task = task;
1391 goto retry;
1392 }
1393
1394 deactivate_task(rq, next_task, 0);
1395 set_task_cpu(next_task, later_rq->cpu);
1396 activate_task(later_rq, next_task, 0);
1397
Kirill Tkhai88751252014-06-29 00:03:57 +04001398 resched_curr(later_rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001399
1400 double_unlock_balance(rq, later_rq);
1401
1402out:
1403 put_task_struct(next_task);
1404
1405 return 1;
1406}
1407
1408static void push_dl_tasks(struct rq *rq)
1409{
1410 /* Terminates as it moves a -deadline task */
1411 while (push_dl_task(rq))
1412 ;
1413}
1414
1415static int pull_dl_task(struct rq *this_rq)
1416{
1417 int this_cpu = this_rq->cpu, ret = 0, cpu;
1418 struct task_struct *p;
1419 struct rq *src_rq;
1420 u64 dmin = LONG_MAX;
1421
1422 if (likely(!dl_overloaded(this_rq)))
1423 return 0;
1424
1425 /*
1426 * Match the barrier from dl_set_overloaded; this guarantees that if we
1427 * see overloaded we must also see the dlo_mask bit.
1428 */
1429 smp_rmb();
1430
1431 for_each_cpu(cpu, this_rq->rd->dlo_mask) {
1432 if (this_cpu == cpu)
1433 continue;
1434
1435 src_rq = cpu_rq(cpu);
1436
1437 /*
1438 * It looks racy, abd it is! However, as in sched_rt.c,
1439 * we are fine with this.
1440 */
1441 if (this_rq->dl.dl_nr_running &&
1442 dl_time_before(this_rq->dl.earliest_dl.curr,
1443 src_rq->dl.earliest_dl.next))
1444 continue;
1445
1446 /* Might drop this_rq->lock */
1447 double_lock_balance(this_rq, src_rq);
1448
1449 /*
1450 * If there are no more pullable tasks on the
1451 * rq, we're done with it.
1452 */
1453 if (src_rq->dl.dl_nr_running <= 1)
1454 goto skip;
1455
1456 p = pick_next_earliest_dl_task(src_rq, this_cpu);
1457
1458 /*
1459 * We found a task to be pulled if:
1460 * - it preempts our current (if there's one),
1461 * - it will preempt the last one we pulled (if any).
1462 */
1463 if (p && dl_time_before(p->dl.deadline, dmin) &&
1464 (!this_rq->dl.dl_nr_running ||
1465 dl_time_before(p->dl.deadline,
1466 this_rq->dl.earliest_dl.curr))) {
1467 WARN_ON(p == src_rq->curr);
Kirill Tkhaida0c1e62014-08-20 13:47:32 +04001468 WARN_ON(!task_on_rq_queued(p));
Juri Lelli1baca4c2013-11-07 14:43:38 +01001469
1470 /*
1471 * Then we pull iff p has actually an earlier
1472 * deadline than the current task of its runqueue.
1473 */
1474 if (dl_time_before(p->dl.deadline,
1475 src_rq->curr->dl.deadline))
1476 goto skip;
1477
1478 ret = 1;
1479
1480 deactivate_task(src_rq, p, 0);
1481 set_task_cpu(p, this_cpu);
1482 activate_task(this_rq, p, 0);
1483 dmin = p->dl.deadline;
1484
1485 /* Is there any other task even earlier? */
1486 }
1487skip:
1488 double_unlock_balance(this_rq, src_rq);
1489 }
1490
1491 return ret;
1492}
1493
Juri Lelli1baca4c2013-11-07 14:43:38 +01001494static void post_schedule_dl(struct rq *rq)
1495{
1496 push_dl_tasks(rq);
1497}
1498
1499/*
1500 * Since the task is not running and a reschedule is not going to happen
1501 * anytime soon on its runqueue, we try pushing it away now.
1502 */
1503static void task_woken_dl(struct rq *rq, struct task_struct *p)
1504{
1505 if (!task_running(rq, p) &&
1506 !test_tsk_need_resched(rq->curr) &&
1507 has_pushable_dl_tasks(rq) &&
1508 p->nr_cpus_allowed > 1 &&
1509 dl_task(rq->curr) &&
1510 (rq->curr->nr_cpus_allowed < 2 ||
1511 dl_entity_preempt(&rq->curr->dl, &p->dl))) {
1512 push_dl_tasks(rq);
1513 }
1514}
1515
1516static void set_cpus_allowed_dl(struct task_struct *p,
1517 const struct cpumask *new_mask)
1518{
1519 struct rq *rq;
1520 int weight;
1521
1522 BUG_ON(!dl_task(p));
1523
1524 /*
1525 * Update only if the task is actually running (i.e.,
1526 * it is on the rq AND it is not throttled).
1527 */
1528 if (!on_dl_rq(&p->dl))
1529 return;
1530
1531 weight = cpumask_weight(new_mask);
1532
1533 /*
1534 * Only update if the process changes its state from whether it
1535 * can migrate or not.
1536 */
1537 if ((p->nr_cpus_allowed > 1) == (weight > 1))
1538 return;
1539
1540 rq = task_rq(p);
1541
1542 /*
1543 * The process used to be able to migrate OR it can now migrate
1544 */
1545 if (weight <= 1) {
1546 if (!task_current(rq, p))
1547 dequeue_pushable_dl_task(rq, p);
1548 BUG_ON(!rq->dl.dl_nr_migratory);
1549 rq->dl.dl_nr_migratory--;
1550 } else {
1551 if (!task_current(rq, p))
1552 enqueue_pushable_dl_task(rq, p);
1553 rq->dl.dl_nr_migratory++;
1554 }
1555
1556 update_dl_migration(&rq->dl);
1557}
1558
1559/* Assumes rq->lock is held */
1560static void rq_online_dl(struct rq *rq)
1561{
1562 if (rq->dl.overloaded)
1563 dl_set_overload(rq);
Juri Lelli6bfd6d72013-11-07 14:43:47 +01001564
1565 if (rq->dl.dl_nr_running > 0)
1566 cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr, 1);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001567}
1568
1569/* Assumes rq->lock is held */
1570static void rq_offline_dl(struct rq *rq)
1571{
1572 if (rq->dl.overloaded)
1573 dl_clear_overload(rq);
Juri Lelli6bfd6d72013-11-07 14:43:47 +01001574
1575 cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001576}
1577
1578void init_sched_dl_class(void)
1579{
1580 unsigned int i;
1581
1582 for_each_possible_cpu(i)
1583 zalloc_cpumask_var_node(&per_cpu(local_cpu_mask_dl, i),
1584 GFP_KERNEL, cpu_to_node(i));
1585}
1586
1587#endif /* CONFIG_SMP */
1588
Dario Faggioliaab03e02013-11-28 11:14:43 +01001589static void switched_from_dl(struct rq *rq, struct task_struct *p)
1590{
Juri Lelli1baca4c2013-11-07 14:43:38 +01001591 if (hrtimer_active(&p->dl.dl_timer) && !dl_policy(p->policy))
Dario Faggioliaab03e02013-11-28 11:14:43 +01001592 hrtimer_try_to_cancel(&p->dl.dl_timer);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001593
Juri Lellia5e7be32014-09-19 10:22:39 +01001594 __dl_clear_params(p);
1595
Juri Lelli1baca4c2013-11-07 14:43:38 +01001596#ifdef CONFIG_SMP
1597 /*
1598 * Since this might be the only -deadline task on the rq,
1599 * this is the right place to try to pull some other one
1600 * from an overloaded cpu, if any.
1601 */
1602 if (!rq->dl.dl_nr_running)
1603 pull_dl_task(rq);
1604#endif
Dario Faggioliaab03e02013-11-28 11:14:43 +01001605}
1606
Juri Lelli1baca4c2013-11-07 14:43:38 +01001607/*
1608 * When switching to -deadline, we may overload the rq, then
1609 * we try to push someone off, if possible.
1610 */
Dario Faggioliaab03e02013-11-28 11:14:43 +01001611static void switched_to_dl(struct rq *rq, struct task_struct *p)
1612{
Juri Lelli1baca4c2013-11-07 14:43:38 +01001613 int check_resched = 1;
1614
Dario Faggioliaab03e02013-11-28 11:14:43 +01001615 /*
1616 * If p is throttled, don't consider the possibility
1617 * of preempting rq->curr, the check will be done right
1618 * after its runtime will get replenished.
1619 */
1620 if (unlikely(p->dl.dl_throttled))
1621 return;
1622
Kirill Tkhaida0c1e62014-08-20 13:47:32 +04001623 if (task_on_rq_queued(p) && rq->curr != p) {
Juri Lelli1baca4c2013-11-07 14:43:38 +01001624#ifdef CONFIG_SMP
1625 if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p))
1626 /* Only reschedule if pushing failed */
1627 check_resched = 0;
1628#endif /* CONFIG_SMP */
1629 if (check_resched && task_has_dl_policy(rq->curr))
Dario Faggioliaab03e02013-11-28 11:14:43 +01001630 check_preempt_curr_dl(rq, p, 0);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001631 }
1632}
1633
Juri Lelli1baca4c2013-11-07 14:43:38 +01001634/*
1635 * If the scheduling parameters of a -deadline task changed,
1636 * a push or pull operation might be needed.
1637 */
Dario Faggioliaab03e02013-11-28 11:14:43 +01001638static void prio_changed_dl(struct rq *rq, struct task_struct *p,
1639 int oldprio)
1640{
Kirill Tkhaida0c1e62014-08-20 13:47:32 +04001641 if (task_on_rq_queued(p) || rq->curr == p) {
Dario Faggioliaab03e02013-11-28 11:14:43 +01001642#ifdef CONFIG_SMP
Juri Lelli1baca4c2013-11-07 14:43:38 +01001643 /*
1644 * This might be too much, but unfortunately
1645 * we don't have the old deadline value, and
1646 * we can't argue if the task is increasing
1647 * or lowering its prio, so...
1648 */
1649 if (!rq->dl.overloaded)
1650 pull_dl_task(rq);
1651
1652 /*
1653 * If we now have a earlier deadline task than p,
1654 * then reschedule, provided p is still on this
1655 * runqueue.
1656 */
1657 if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline) &&
1658 rq->curr == p)
Kirill Tkhai88751252014-06-29 00:03:57 +04001659 resched_curr(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001660#else
1661 /*
1662 * Again, we don't know if p has a earlier
1663 * or later deadline, so let's blindly set a
1664 * (maybe not needed) rescheduling point.
1665 */
Kirill Tkhai88751252014-06-29 00:03:57 +04001666 resched_curr(rq);
Juri Lelli1baca4c2013-11-07 14:43:38 +01001667#endif /* CONFIG_SMP */
1668 } else
1669 switched_to_dl(rq, p);
Dario Faggioliaab03e02013-11-28 11:14:43 +01001670}
Dario Faggioliaab03e02013-11-28 11:14:43 +01001671
1672const struct sched_class dl_sched_class = {
1673 .next = &rt_sched_class,
1674 .enqueue_task = enqueue_task_dl,
1675 .dequeue_task = dequeue_task_dl,
1676 .yield_task = yield_task_dl,
1677
1678 .check_preempt_curr = check_preempt_curr_dl,
1679
1680 .pick_next_task = pick_next_task_dl,
1681 .put_prev_task = put_prev_task_dl,
1682
1683#ifdef CONFIG_SMP
1684 .select_task_rq = select_task_rq_dl,
Juri Lelli1baca4c2013-11-07 14:43:38 +01001685 .set_cpus_allowed = set_cpus_allowed_dl,
1686 .rq_online = rq_online_dl,
1687 .rq_offline = rq_offline_dl,
Juri Lelli1baca4c2013-11-07 14:43:38 +01001688 .post_schedule = post_schedule_dl,
1689 .task_woken = task_woken_dl,
Dario Faggioliaab03e02013-11-28 11:14:43 +01001690#endif
1691
1692 .set_curr_task = set_curr_task_dl,
1693 .task_tick = task_tick_dl,
1694 .task_fork = task_fork_dl,
1695 .task_dead = task_dead_dl,
1696
1697 .prio_changed = prio_changed_dl,
1698 .switched_from = switched_from_dl,
1699 .switched_to = switched_to_dl,
1700};