linux-kernel - [PATCH 2/5] blk-mq: bitmap tag: remove barrier in bt_clear

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 11 May 2014 01:01:49 +0800
From:	Ming Lei <tom.leiming@...il.com>
To:	Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org
Cc:	Ming Lei <tom.leiming@...il.com>
Subject: [PATCH 2/5] 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@...il.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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/