diff options
| -rw-r--r-- | kernel/sched/core.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index cc814933f7d6..d8d76a65cfdd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -417,10 +417,11 @@ void wake_q_add(struct wake_q_head *head, struct task_struct *task) * its already queued (either by us or someone else) and will get the * wakeup due to that. * - * This cmpxchg() executes a full barrier, which pairs with the full - * barrier executed by the wakeup in wake_up_q(). + * In order to ensure that a pending wakeup will observe our pending + * state, even in the failed case, an explicit smp_mb() must be used. */ - if (cmpxchg(&node->next, NULL, WAKE_Q_TAIL)) + smp_mb__before_atomic(); + if (cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL)) return; get_task_struct(task); |