[PATCH v5 5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock
From: Pan Xinhui <hidden>
Date: 2016-06-02 09:27:43
Also in:
lkml
Subsystem:
locking primitives, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Linus Torvalds
cmpxchg_release is light-wight than cmpxchg, On some arch like ppc, barrier impact the performace too much. 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;
--
2.4.11