From ef3230880abd36553ab442363d3c9a0661f00769 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Sat, 23 Jul 2011 20:44:24 +0200 Subject: [PATCH] backing-dev: use synchronize_rcu_expedited instead of synchronize_rcu backing-dev: use synchronize_rcu_expedited instead of synchronize_rcu synchronize_rcu sleeps several timer ticks. synchronize_rcu_expedited is much faster. With 100Hz timer frequency, when we remove 10000 block devices with "dmsetup remove_all" command, it takes 27 minutes. With this patch, removing 10000 block devices takes only 15 seconds. Signed-off-by: Mikulas Patocka Signed-off-by: Jens Axboe --- mm/backing-dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f032e6e1e09a..2ef0dc9e7f39 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -505,7 +505,7 @@ static void bdi_remove_from_list(struct backing_dev_info *bdi) list_del_rcu(&bdi->bdi_list); spin_unlock_bh(&bdi_lock); - synchronize_rcu(); + synchronize_rcu_expedited(); } int bdi_register(struct backing_dev_info *bdi, struct device *parent,