From 7b1fb0c526936873a260e860ce3bca82113c3d4c Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 22 Apr 2015 03:16:50 -0400 Subject: [PATCH] optimize spin lock not to dirty cache line while spinning --- src/thread/pthread_spin_lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/thread/pthread_spin_lock.c b/src/thread/pthread_spin_lock.c index df575f08..0462e0f3 100644 --- a/src/thread/pthread_spin_lock.c +++ b/src/thread/pthread_spin_lock.c @@ -2,6 +2,6 @@ int pthread_spin_lock(pthread_spinlock_t *s) { - while (a_swap(s, 1)) a_spin(); + while (*(volatile int *)s || a_cas(s, 0, 1)) a_spin(); return 0; } -- 2.25.1