diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-04-13 11:08:20 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-04-13 11:08:20 -0400 |
commit | 6631e635c65dc33cb798cc2f51d0ddd69ada6319 (patch) | |
tree | c71585118b3ddd42b1bf666fef9f96e60b79f757 /kernel | |
parent | a626ca6a656450e9f4df91d0dda238fff23285f4 (diff) |
block: don't flush plugged IO on forced preemtion scheduling
We really only want to unplug the pending IO when the process actually
goes to sleep. So move the test for flushing the plug up to the place
where we actually deactivate the task - where we have properly checked
for preemption and for the process really sleeping.
Acked-by: Jens Axboe <jaxboe@fusionio.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/sched.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 48013633d792..a187c3fe027b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c | |||
@@ -4111,20 +4111,20 @@ need_resched: | |||
4111 | try_to_wake_up_local(to_wakeup); | 4111 | try_to_wake_up_local(to_wakeup); |
4112 | } | 4112 | } |
4113 | deactivate_task(rq, prev, DEQUEUE_SLEEP); | 4113 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
4114 | |||
4115 | /* | ||
4116 | * If we are going to sleep and we have plugged IO queued, make | ||
4117 | * sure to submit it to avoid deadlocks. | ||
4118 | */ | ||
4119 | if (blk_needs_flush_plug(prev)) { | ||
4120 | raw_spin_unlock(&rq->lock); | ||
4121 | blk_flush_plug(prev); | ||
4122 | raw_spin_lock(&rq->lock); | ||
4123 | } | ||
4114 | } | 4124 | } |
4115 | switch_count = &prev->nvcsw; | 4125 | switch_count = &prev->nvcsw; |
4116 | } | 4126 | } |
4117 | 4127 | ||
4118 | /* | ||
4119 | * If we are going to sleep and we have plugged IO queued, make | ||
4120 | * sure to submit it to avoid deadlocks. | ||
4121 | */ | ||
4122 | if (prev->state != TASK_RUNNING && blk_needs_flush_plug(prev)) { | ||
4123 | raw_spin_unlock(&rq->lock); | ||
4124 | blk_flush_plug(prev); | ||
4125 | raw_spin_lock(&rq->lock); | ||
4126 | } | ||
4127 | |||
4128 | pre_schedule(rq, prev); | 4128 | pre_schedule(rq, prev); |
4129 | 4129 | ||
4130 | if (unlikely(!rq->nr_running)) | 4130 | if (unlikely(!rq->nr_running)) |