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>
mariux64 · May 10, 2014 · 60f2df8 · 60f2df8
1 parent 0289b2e
commit 60f2df8
Showing 1 changed file with 0 additions and 1 deletion.
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
@@ -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);