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[v5,5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock

Message ID 1464859590-5292-7-git-send-email-xinhui.pan@linux.vnet.ibm.com (mailing list archive)
State Superseded
Headers show

Commit Message

xinhui June 2, 2016, 9:26 a.m. UTC
cmpxchg_release is light-wight than cmpxchg, On some arch like ppc,
barrier impact the performace too much.

Suggested-by:  Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
 kernel/locking/qspinlock_paravirt.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index a5b1248..2bbffe4 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -614,7 +614,7 @@  __visible void __pv_queued_spin_unlock(struct qspinlock *lock)
 	 * unhash. Otherwise it would be possible to have multiple @lock
 	 * entries, which would be BAD.
 	 */
-	locked = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
+	locked = cmpxchg_release(&l->locked, _Q_LOCKED_VAL, 0);
 	if (likely(locked == _Q_LOCKED_VAL))
 		return;