Commit-ID: d49db342f0e276b354383b3281c5668b6b80f5c2 Gitweb: http://git.kernel.org/tip/d49db342f0e276b354383b3281c5668b6b80f5c2 Author: Cong Wang <xiyou.wangcong@xxxxxxxxx> AuthorDate: Wed, 24 Jun 2015 12:41:47 -0700 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Mon, 6 Jul 2015 14:15:08 +0200 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@xxxxxxxxx> Signed-off-by: Cong Wang <cwang@xxxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Reviewed-by: Ben Segall <bsegall@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1435174907-432-1-git-send-email-xiyou.wangcong@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 65c8f3e..d113c3b 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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