diff options
author | Alex Shi <alex.shi@linaro.org> | 2014-01-10 10:50:57 +0800 |
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committer | Alex Shi <alex.shi@linaro.org> | 2014-01-10 10:50:57 +0800 |
commit | 450cdfa9c5713551ab1438ab210679868b52a994 (patch) | |
tree | edd98f9698aa88af55a3a1ee3de62e52917c39ba /kernel/sched/core.c | |
parent | bf78886fb6c4131885f84f3eaaf7474509d40e51 (diff) | |
parent | 8b4ed85b8404ffe7e10ee410c4df3968b86f0793 (diff) |
Merge remote-tracking branch 'stable/linux-3.10.y' into linux-linaro-lsk
Conflicts:
arch/arm64/kernel/smp.c
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r-- | kernel/sched/core.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fb9b7b74a83..fc5112c20fe 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1487,7 +1487,13 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) unsigned long flags; int cpu, success = 0; - smp_wmb(); + /* + * If we are going to wake up a thread waiting for CONDITION we + * need to ensure that CONDITION=1 done by the caller can not be + * reordered with p->state check below. This pairs with mb() in + * set_current_state() the waiting thread does. + */ + smp_mb__before_spinlock(); raw_spin_lock_irqsave(&p->pi_lock, flags); if (!(p->state & state)) goto out; @@ -2980,6 +2986,12 @@ need_resched: if (sched_feat(HRTICK)) hrtick_clear(rq); + /* + * Make sure that signal_pending_state()->signal_pending() below + * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) + * done by the caller to avoid the race with signal_wake_up(). + */ + smp_mb__before_spinlock(); raw_spin_lock_irq(&rq->lock); switch_count = &prev->nivcsw; |