diff options
author | Peter Zijlstra <peterz@infradead.org> | 2014-11-26 00:44:03 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-02-04 06:52:26 (GMT) |
commit | 1019a359d3dc4b64d0e1e5a5efcb725d5e83994d (patch) | |
tree | e3ea8601967f078e09dc436670cf8dfcd903311d /kernel | |
parent | a7bebf488791aa1036f3e6629daf01d01f705dcb (diff) | |
download | linux-1019a359d3dc4b64d0e1e5a5efcb725d5e83994d.tar.xz |
sched/deadline: Fix stale yield state
When we fail to start the deadline timer in update_curr_dl(), we
forget to clear ->dl_yielded, resulting in wrecked time keeping.
Since the natural place to clear both ->dl_yielded and ->dl_throttled
is in replenish_dl_entity(); both are after all waiting for that event;
make it so.
Luckily since 67dfa1b756f2 ("sched/deadline: Implement
cancel_dl_timer() to use in switched_from_dl()") the
task_on_rq_queued() condition in dl_task_timer() must be true, and can
therefore call enqueue_task_dl() unconditionally.
Reported-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kirill Tkhai <ktkhai@parallels.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1416962647-76792-4-git-send-email-wanpeng.li@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/sched/deadline.c | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 7b684f9..a027799 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -350,6 +350,11 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se, dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline; dl_se->runtime = pi_se->dl_runtime; } + + if (dl_se->dl_yielded) + dl_se->dl_yielded = 0; + if (dl_se->dl_throttled) + dl_se->dl_throttled = 0; } /* @@ -536,23 +541,19 @@ again: sched_clock_tick(); update_rq_clock(rq); - dl_se->dl_throttled = 0; - dl_se->dl_yielded = 0; - if (task_on_rq_queued(p)) { - enqueue_task_dl(rq, p, ENQUEUE_REPLENISH); - if (dl_task(rq->curr)) - check_preempt_curr_dl(rq, p, 0); - else - resched_curr(rq); + enqueue_task_dl(rq, p, ENQUEUE_REPLENISH); + if (dl_task(rq->curr)) + check_preempt_curr_dl(rq, p, 0); + else + resched_curr(rq); #ifdef CONFIG_SMP - /* - * Queueing this task back might have overloaded rq, - * check if we need to kick someone away. - */ - if (has_pushable_dl_tasks(rq)) - push_dl_task(rq); + /* + * Queueing this task back might have overloaded rq, + * check if we need to kick someone away. + */ + if (has_pushable_dl_tasks(rq)) + push_dl_task(rq); #endif - } unlock: raw_spin_unlock(&rq->lock); @@ -613,10 +614,9 @@ static void update_curr_dl(struct rq *rq) dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec; if (dl_runtime_exceeded(rq, dl_se)) { + dl_se->dl_throttled = 1; __dequeue_task_dl(rq, curr, 0); - if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted))) - dl_se->dl_throttled = 1; - else + if (unlikely(!start_dl_timer(dl_se, curr->dl.dl_boosted))) enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH); if (!is_leftmost(curr, &rq->dl)) @@ -853,7 +853,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) * its rq, the bandwidth timer callback (which clearly has not * run yet) will take care of this. */ - if (p->dl.dl_throttled) + if (p->dl.dl_throttled && !(flags & ENQUEUE_REPLENISH)) return; enqueue_dl_entity(&p->dl, pi_se, flags); |