Thread (1 message) 1 message, 1 author, 2016-05-17

[PATCH v2 5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock

STALE3790d

From: Pan Xinhui <hidden>
Date: 2016-05-17 07:49:46
Subsystem: locking primitives, the rest · Maintainers: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Linus Torvalds

cmpxchg_release is lighter, we can gain a better performace then.

Suggested-by: Boqun Feng <redacted>
Signed-off-by: Pan Xinhui <redacted>
---
 kernel/locking/qspinlock_paravirt.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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;
 
-- 
1.9.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help