Messages in this thread Patch in this message | | | From | Pan Xinhui <> | Subject | [PATCH v4 5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock | Date | Wed, 1 Jun 2016 20:00:46 +0800 |
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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 --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
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