diff options
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 256e577faf1b..5285332392d5 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -518,12 +518,20 @@ again: } /* - * We need to take care of a possible races here. In fact, the - * task might have changed its scheduling policy to something - * different from SCHED_DEADLINE or changed its reservation - * parameters (through sched_setattr()). + * We need to take care of several possible races here: + * + * - the task might have changed its scheduling policy + * to something different than SCHED_DEADLINE + * - the task might have changed its reservation parameters + * (through sched_setattr()) + * - the task might have been boosted by someone else and + * might be in the boosting/deboosting path + * + * In all this cases we bail out, as the task is already + * in the runqueue or is going to be enqueued back anyway. */ - if (!dl_task(p) || dl_se->dl_new) + if (!dl_task(p) || dl_se->dl_new || + dl_se->dl_boosted || !dl_se->dl_throttled) goto unlock; sched_clock_tick(); @@ -532,7 +540,7 @@ again: dl_se->dl_yielded = 0; if (task_on_rq_queued(p)) { enqueue_task_dl(rq, p, ENQUEUE_REPLENISH); - if (task_has_dl_policy(rq->curr)) + if (dl_task(rq->curr)) check_preempt_curr_dl(rq, p, 0); else resched_curr(rq); @@ -847,8 +855,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) * smaller than our one... OTW we keep our runtime and * deadline. */ - if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) + if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) { pi_se = &pi_task->dl; + } else if (!dl_prio(p->normal_prio)) { + /* + * Special case in which we have a !SCHED_DEADLINE task + * that is going to be deboosted, but exceedes its + * runtime while doing so. No point in replenishing + * it, as it's going to return back to its original + * scheduling class after this. + */ + BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH); + return; + } /* * If p is throttled, we do nothing. In fact, if it exhausted @@ -1607,8 +1626,12 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) /* Only reschedule if pushing failed */ check_resched = 0; #endif /* CONFIG_SMP */ - if (check_resched && task_has_dl_policy(rq->curr)) - check_preempt_curr_dl(rq, p, 0); + if (check_resched) { + if (dl_task(rq->curr)) + check_preempt_curr_dl(rq, p, 0); + else + resched_curr(rq); + } } } |