diff options
Diffstat (limited to 'kernel/locking/osq_lock.c')
| -rw-r--r-- | kernel/locking/osq_lock.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c index 1f7734949ac8..d5610ad52b92 100644 --- a/kernel/locking/osq_lock.c +++ b/kernel/locking/osq_lock.c @@ -135,7 +135,7 @@ bool osq_lock(struct optimistic_spin_queue *lock) */ /* - * Wait to acquire the lock or cancelation. Note that need_resched() + * Wait to acquire the lock or cancellation. Note that need_resched() * will come with an IPI, which will wake smp_cond_load_relaxed() if it * is implemented with a monitor-wait. vcpu_is_preempted() relies on * polling, be careful. @@ -154,13 +154,17 @@ bool osq_lock(struct optimistic_spin_queue *lock) */ for (;;) { - if (prev->next == node && + /* + * cpu_relax() below implies a compiler barrier which would + * prevent this comparison being optimized away. + */ + if (data_race(prev->next) == node && cmpxchg(&prev->next, node, NULL) == node) break; /* * We can only fail the cmpxchg() racing against an unlock(), - * in which case we should observe @node->locked becomming + * in which case we should observe @node->locked becoming * true. */ if (smp_load_acquire(&node->locked)) |