From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030800AbXCGOpv (ORCPT ); Wed, 7 Mar 2007 09:45:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030794AbXCGOpv (ORCPT ); Wed, 7 Mar 2007 09:45:51 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:60461 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030800AbXCGOpu (ORCPT ); Wed, 7 Mar 2007 09:45:50 -0500 Date: Wed, 7 Mar 2007 20:22:57 +0530 From: Srivatsa Vaddagiri To: menage@google.com Cc: akpm@osdl.org, pj@sgi.com, sekharan@us.ibm.com, dev@sw.ru, xemul@sw.ru, serue@us.ibm.com, ebiederm@xmission.com, ckrm-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org, rohitseth@google.com, mbligh@google.com, winget@google.com, containers@lists.osdl.org, devel@openvz.org Subject: Re: [PATCH 2/7] containers (V7): Cpusets hooked into containers Message-ID: <20070307145257.GD32105@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20070212081521.808338000@menage.corp.google.com> <20070212085104.290909000@menage.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070212085104.290909000@menage.corp.google.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 12, 2007 at 12:15:23AM -0800, menage@google.com wrote: > - mutex_lock(&callback_mutex); > - list_add(&cs->sibling, &cs->parent->children); > + cont->cpuset = cs; > + cs->container = cont; > number_of_cpusets++; > - mutex_unlock(&callback_mutex); What's the rule to read/write number_of_cpusets? The earlier cpuset code was incrementing/decrementing under callback_mutex, but now we aren't. How safe is that? The earlier cpuset code also was reading number_of_cpusets w/o the callback_mutex held (atleast in cpuset_zone_allowed_softwall). Is that safe? -- Regards, vatsa