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| author | Cong Wang <xiyou.wangcong@gmail.com> | 2015-06-24 21:41:47 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-07-06 14:15:08 +0200 |
| commit | d49db342f0e276b354383b3281c5668b6b80f5c2 (patch) | |
| tree | 646345871947652187cedb234ee08ffb2ef4974e /kernel/sched/fair.c | |
| parent | Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kerne... (diff) | |
| download | linux-d49db342f0e276b354383b3281c5668b6b80f5c2.tar.xz linux-d49db342f0e276b354383b3281c5668b6b80f5c2.zip | |
sched/fair: Test list head instead of list entry in throttle_cfs_rq()
According to the comments, we need to test if this is
the first throttled task, however, list_empty() tests on
the entry cfs_rq->throttled_list, not the head, this is wrong.
This is a bug because we don't re-init the list entry after
removing it from the list, so list_empty() could return false
even if the list is really empty.
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435174907-432-1-git-send-email-xiyou.wangcong@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | kernel/sched/fair.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 65c8f3ebdc3c..d113c3ba8bc4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3683,7 +3683,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) cfs_rq->throttled = 1; cfs_rq->throttled_clock = rq_clock(rq); raw_spin_lock(&cfs_b->lock); - empty = list_empty(&cfs_rq->throttled_list); + empty = list_empty(&cfs_b->throttled_cfs_rq); /* * Add to the _head_ of the list, so that an already-started |