From: Ming Lei <tom.leiming@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, linux-kernel@vger.kernel.org
Cc: Ming Lei <tom.leiming@gmail.com>
Subject: [PATCH 2/5] blk-mq: bitmap tag: remove barrier in bt_clear_tag()
Date: Sun, 11 May 2014 01:01:49 +0800 [thread overview]
Message-ID: <1399741312-10453-3-git-send-email-tom.leiming@gmail.com> (raw)
In-Reply-To: <1399741312-10453-1-git-send-email-tom.leiming@gmail.com>
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>
---
block/blk-mq-tag.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index b8b968d..777aad7 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -243,7 +243,6 @@ 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_WAIT_BATCH);
bt_index_inc(&bt->wake_index);
wake_up(&bs->wait);
--
1.7.9.5
next prev parent reply other threads:[~2014-05-10 17:02 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-10 17:01 [PATCH 0/5] blk-mq: bitmap tag: fix and cleanup Ming Lei
2014-05-10 17:01 ` [PATCH 1/5] blk-mq: bitmap tag: use clear_bit_unlock in bt_clear_tag() Ming Lei
2014-05-10 17:01 ` Ming Lei [this message]
2014-05-10 17:01 ` [PATCH 3/5] blk-mq: bitmap tag: select random tag betweet 0 and (depth - 1) Ming Lei
2014-05-10 17:01 ` [PATCH 4/5] blk-mq: bitmap tag: cleanup blk_mq_init_tags Ming Lei
2014-05-10 17:01 ` [PATCH 5/5] blk-mq: bitmap tag: fix wait batch for allocation Ming Lei
2014-05-10 19:39 ` [PATCH 0/5] blk-mq: bitmap tag: fix and cleanup Jens Axboe
2014-05-11 1:13 ` Ming Lei
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