Commit ef323088 authored Jul 23, 2011 by Mikulas Patocka Committed by Jens Axboe Jul 23, 2011

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 <mpatocka@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

parent 4c64500e

mm/backing-dev.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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,

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