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author | Peter Zijlstra <peterz@infradead.org> | 2013-11-20 12:22:37 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2014-01-13 17:38:55 +0100 |
commit | 8cb75e0c4ec9786b81439761eac1d18d4a931af3 (patch) | |
tree | 9d13e6c3580a36cd76d1b3a96827795949519409 /kernel/sched | |
parent | c9c8986847d2f4fc474c10ee08afa57e7474096d (diff) | |
download | op-kernel-dev-8cb75e0c4ec9786b81439761eac1d18d4a931af3.zip op-kernel-dev-8cb75e0c4ec9786b81439761eac1d18d4a931af3.tar.gz |
sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding
With various drivers wanting to inject idle time; we get people
calling idle routines outside of the idle loop proper.
Therefore we need to be extra careful about not missing
TIF_NEED_RESCHED -> PREEMPT_NEED_RESCHED propagations.
While looking at this, I also realized there's a small window in the
existing idle loop where we can miss TIF_NEED_RESCHED; when it hits
right after the tif_need_resched() test at the end of the loop but
right before the need_resched() test at the start of the loop.
So move preempt_fold_need_resched() out of the loop where we're
guaranteed to have TIF_NEED_RESCHED set.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-x9jgh45oeayzajz2mjt0y7d6@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r-- | kernel/sched/core.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 392c6f8..0326c06 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1510,8 +1510,7 @@ void scheduler_ipi(void) * TIF_NEED_RESCHED remotely (for the first time) will also send * this IPI. */ - if (tif_need_resched()) - set_preempt_need_resched(); + preempt_fold_need_resched(); if (llist_empty(&this_rq()->wake_list) && !tick_nohz_full_cpu(smp_processor_id()) |