From mboxrd@z Thu Jan 1 00:00:00 1970 From: "kedacomkernel" Subject: [Patch]use atomic_dec_return() instead of atomic_dec() and atomic_read() Date: Wed, 29 Feb 2012 15:07:52 +0800 Message-ID: <201202291507476878071@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: linux-raid List-Id: linux-raid.ids >From ebdcb976dc5c7aa992f8bd682babffbbb143de18 Mon Sep 17 00:00:00 2001 From: majianpeng Date: Wed, 29 Feb 2012 15:05:17 +0800 Subject: [PATCH] md:use atomic_dec_return() instead of atomic_dec() and atomic_read(). Signed-off-by: majianpeng --- drivers/md/raid5.c | 8 +++----- 1 files changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 360f2b9..9b58d05 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -208,11 +208,9 @@ static void __release_stripe(struct r5conf *conf, struct stripe_head *sh) md_wakeup_thread(conf->mddev->thread); } else { BUG_ON(stripe_operations_active(sh)); - if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) { - atomic_dec(&conf->preread_active_stripes); - if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) - md_wakeup_thread(conf->mddev->thread); - } + if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state) && + (atomic_dec_return(&conf->preread_active_stripes) < IO_THRESHOLD)) + md_wakeup_thread(conf->mddev->thread); atomic_dec(&conf->active_stripes); if (!test_bit(STRIPE_EXPANDING, &sh->state)) { list_add_tail(&sh->lru, &conf->inactive_list); -- 1.7.5.4 -------------- kedacomkernel 2012-02-29