From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758447AbaDVUqc (ORCPT ); Tue, 22 Apr 2014 16:46:32 -0400 Received: from mail-qa0-f42.google.com ([209.85.216.42]:42393 "EHLO mail-qa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758401AbaDVUq1 (ORCPT ); Tue, 22 Apr 2014 16:46:27 -0400 Date: Tue, 22 Apr 2014 16:46:23 -0400 From: Tejun Heo To: Lai Jiangshan Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2 V3] workqueue: substitute POOL_FREEZING with __WQ_FREEZING Message-ID: <20140422204623.GC3615@mtj.dyndns.org> References: <1398081561-12618-1-git-send-email-laijs@cn.fujitsu.com> <20140421222035.GA22730@htj.dyndns.org> <5355CA43.5040608@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5355CA43.5040608@cn.fujitsu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Apr 22, 2014 at 09:47:47AM +0800, Lai Jiangshan wrote: > Testing workqueue_freezing requires wq_pool_mutex held. > Although almost-all pwq_adjust_max_active() are called with wq_pool_mutex held, > except workqueue_set_max_active(). But I hope pwq_adjust_max_active() > don't require the heavy wq_pool_mutex. No it doesn't require wq_pool_mutex to be held. All it requires is that the changed state is visible on the subsequent pwq_adjust_max_active() invocatino which is already trivially guaranteed. Thanks. -- tejun