Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754263AbaLDPLK (ORCPT ); Thu, 4 Dec 2014 10:11:10 -0500 Received: from mail-qg0-f47.google.com ([209.85.192.47]:42418 "EHLO mail-qg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753543AbaLDPLJ (ORCPT ); Thu, 4 Dec 2014 10:11:09 -0500 Date: Thu, 4 Dec 2014 10:11:04 -0500 From: Tejun Heo To: NeilBrown Cc: Jan Kara , Lai Jiangshan , Dongsu Park , linux-kernel@vger.kernel.org Subject: [PATCH workqueue/for-3.18-fixes 1/2] workqueue: invert the order between pool->lock and wq_mayday_lock Message-ID: <20141204151104.GD15219@htj.dyndns.org> References: <20141106165811.GA2338@gmail.com> <545C368C.5040704@cn.fujitsu.com> <20141110162848.6f2246bb@notabene.brown> <20141110085250.GB15948@quack.suse.cz> <20141111090402.35fa0700@notabene.brown> <20141118152754.60b0c75e@notabene.brown> <20141202204304.GR10918@htj.dyndns.org> <20141203114011.5d02dc43@notabene.brown> <20141203172010.GC5013@htj.dyndns.org> <20141203180241.GD5013@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141203180241.GD5013@htj.dyndns.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, pool->lock nests inside pool->lock. There's no inherent reason for this order. The only place where the two locks are held together is pool_mayday_timeout() and it just got decided that way. This nesting order turns out to complicate things with the planned rescuer_thread() update. Let's invert them. This doesn't cause any behavior differences. Signed-off-by: Tejun Heo Cc: NeilBrown Cc: Dongsu Park Cc: Lai Jiangshan --- kernel/workqueue.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1804,8 +1804,8 @@ static void pool_mayday_timeout(unsigned struct worker_pool *pool = (void *)__pool; struct work_struct *work; - spin_lock_irq(&wq_mayday_lock); /* for wq->maydays */ - spin_lock(&pool->lock); + spin_lock_irq(&pool->lock); + spin_lock(&wq_mayday_lock); /* for wq->maydays */ if (need_to_create_worker(pool)) { /* @@ -1818,8 +1818,8 @@ static void pool_mayday_timeout(unsigned send_mayday(work); } - spin_unlock(&pool->lock); - spin_unlock_irq(&wq_mayday_lock); + spin_unlock(&wq_mayday_lock); + spin_unlock_irq(&pool->lock); mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/