From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946520AbXD3RJ5 (ORCPT ); Mon, 30 Apr 2007 13:09:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946519AbXD3RJ5 (ORCPT ); Mon, 30 Apr 2007 13:09:57 -0400 Received: from smtp-out.google.com ([216.239.45.13]:49743 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946520AbXD3RJy (ORCPT ); Mon, 30 Apr 2007 13:09:54 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=NIWV+5H8/vcRqfkMAUPbX12m8XkxkBrdtEvV6ojhJJgX5ZKloAIw7n9iIvT91bliV q6v+9OugVsI43mRfA9zWA== Message-ID: <6599ad830704301009k11100a78we98e20deba9b1fdc@mail.gmail.com> Date: Mon, 30 Apr 2007 10:09:38 -0700 From: "Paul Menage" To: vatsa@in.ibm.com, "Paul Jackson" Subject: Re: [PATCH 0/9] Containers (V9): Generic Process Containers Cc: akpm@linux-foundation.org, dev@sw.ru, xemul@sw.ru, serue@us.ibm.com, ebiederm@xmission.com, haveblue@us.ibm.com, svaidy@linux.vnet.ibm.com, balbir@in.ibm.com, ckrm-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org, rohitseth@google.com, mbligh@google.com, containers@lists.osdl.org, devel@openvz.org In-Reply-To: <20070430171225.GH24350@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070427104607.252541000@menage.corp.google.com> <20070429023721.53f249b9.pj@sgi.com> <20070430171225.GH24350@in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 4/30/07, Srivatsa Vaddagiri wrote: > On Sun, Apr 29, 2007 at 02:37:21AM -0700, Paul Jackson wrote: > > It builds and boots and mounts the cpuset file system ok. > > But trying to write the 'mems' file hangs the system hard. > > Basically we are attempting a read_lock(&tasklist_lock) in > container_task_count() after taking write_lock_irq(&tasklist_lock) in > update_nodemask()! Paul, is there any reason why we need to do a write_lock() on tasklist_lock if we're just trying to block fork, or is it just historical accident? Wouldn't it be fine to do a read_lock()? Paul