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>
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index f032e6e..2ef0dc9 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -505,7 +505,7 @@
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,