From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [md PATCH 05/23] md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read(). Date: Wed, 14 Mar 2012 15:40:39 +1100 Message-ID: <20120314044039.7978.6916.stgit@notabene.brown> References: <20120314043555.7978.75486.stgit@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120314043555.7978.75486.stgit@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids From: majianpeng Signed-off-by: majianpeng Signed-off-by: NeilBrown --- drivers/md/raid5.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 3f55145..99b2bbf 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -208,11 +208,10 @@ 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) + if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + if (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);