From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754428Ab2H3ChJ (ORCPT ); Wed, 29 Aug 2012 22:37:09 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:53721 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753638Ab2H3ChH (ORCPT ); Wed, 29 Aug 2012 22:37:07 -0400 X-IronPort-AV: E=Sophos;i="4.80,337,1344182400"; d="scan'208";a="5750390" Message-ID: <503ED232.3010501@cn.fujitsu.com> Date: Thu, 30 Aug 2012 10:38:42 +0800 From: Lai Jiangshan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc14 Thunderbird/3.1.4 MIME-Version: 1.0 To: Tejun Heo CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/9 V3] workqueue: add POOL_MANAGING_WORKERS References: <1346259120-6216-1-git-send-email-laijs@cn.fujitsu.com> <1346259120-6216-4-git-send-email-laijs@cn.fujitsu.com> <20120829182102.GA2258@dhcp-172-17-108-109.mtv.corp.google.com> In-Reply-To: <20120829182102.GA2258@dhcp-172-17-108-109.mtv.corp.google.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/30 10:36:52, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/30 10:36:52, Serialize complete at 2012/08/30 10:36:52 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/30/2012 02:21 AM, Tejun Heo wrote: > Hello, Lai. > > On Thu, Aug 30, 2012 at 12:51:54AM +0800, Lai Jiangshan wrote: >> When hotplug happens, the plug code will also grab the manager_mutex, >> it will break too_many_workers()'s assumption, and make too_many_workers() >> ugly(kick the timer wrongly, no found bug). >> >> To avoid assumption-coruption, we add the original POOL_MANAGING_WORKERS back. > > I don't think we're gaining anything with this and I'd like to confine > management state within the mutex only. If too_many_workers() firing > spuriously while CPU up/down is in progress, just add a comment > explaining why it's a non-problem OK, I drop this patch, Could you add the comment, I'm not good at English. > (actual worker management never > happens while cpu up/down holds manager positions). > I don't agree this claim. It happens "rarely", not "never", otherwise I missed something. Thanks, Lai