From 4b05a1c74d1cfae37cf6ff293ee928350f031418 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 27 Nov 2012 22:59:52 -0500 Subject: [PATCH] percpu-rwsem: use synchronize_sched_expedited Use synchronize_sched_expedited() instead of synchronize_sched() to improve mount speed. This patch improves mount time from 0.500s to 0.013s for Jeff's test-case. Signed-off-by: Mikulas Patocka Reported-and-tested-by: Jeff Chua Signed-off-by: Linus Torvalds --- include/linux/percpu-rwsem.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 250a4acddb2b..bd1e86071e57 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -13,7 +13,7 @@ struct percpu_rw_semaphore { }; #define light_mb() barrier() -#define heavy_mb() synchronize_sched() +#define heavy_mb() synchronize_sched_expedited() static inline void percpu_down_read(struct percpu_rw_semaphore *p) { @@ -51,7 +51,7 @@ static inline void percpu_down_write(struct percpu_rw_semaphore *p) { mutex_lock(&p->mtx); p->locked = true; - synchronize_sched(); /* make sure that all readers exit the rcu_read_lock_sched region */ + synchronize_sched_expedited(); /* make sure that all readers exit the rcu_read_lock_sched region */ while (__percpu_count(p->counters)) msleep(1); heavy_mb(); /* C, between read of p->counter and write to data, paired with B */ -- 2.11.0