blk-mq: bitmap tag: remove barrier in bt_clear_tag()

The barrier isn't necessary because both atomic_dec_and_test()
and wake_up() implicate one barrier.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Ming Lei 2014-05-11 01:01:49 +08:00 committed by Jens Axboe
parent 0289b2e110
commit 60f2df8a29

View File

@ -244,7 +244,6 @@ static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag)
bs = bt_wake_ptr(bt);
if (bs && atomic_dec_and_test(&bs->wait_cnt)) {
smp_mb__after_clear_bit();
atomic_set(&bs->wait_cnt, bt->wake_cnt);
bt_index_inc(&bt->wake_index);
wake_up(&bs->wait);