From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932119AbYB1VaM (ORCPT ); Thu, 28 Feb 2008 16:30:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756859AbYB1V3z (ORCPT ); Thu, 28 Feb 2008 16:29:55 -0500 Received: from smtp1.linux-foundation.org ([207.189.120.13]:48299 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756747AbYB1V3y (ORCPT ); Thu, 28 Feb 2008 16:29:54 -0500 Date: Thu, 28 Feb 2008 13:21:42 -0800 From: Andrew Morton To: "Paul Menage" Cc: containers@lists.osdl.org, linux-kernel@vger.kernel.org, balbir@linux.vnet.ibm.com, a.p.zijlstra@chello.nl, xemul@openvz.org, pj@sgi.com Subject: Re: [RFC] Prefixing cgroup generic control filenames with "cgroup." Message-Id: <20080228132142.4d4b1eef.akpm@linux-foundation.org> In-Reply-To: <6599ad830802281314s25c033d6tc021725ae28aef8d@mail.gmail.com> References: <6599ad830802281314s25c033d6tc021725ae28aef8d@mail.gmail.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Feb 2008 13:14:05 -0800 "Paul Menage" wrote: > All control files created by cgroup subsystems are given a prefix > corresponding to their subsystem name. But control files provided by > cgroups itself have no prefix. Currently that set of files is just > "tasks", "notify_on_release" and "release_agent", but that set is > likely to expand in the future. To reduce the risk of clashes, it > would make sense to prefix these files and any future ones with the > "cgroup." prefix. > > The only reason that I can see *not* to do this would be for > compatibility with 2.6.24. Do people think this is a strong enough > reason to leave the existing names? If distros are planning to ship > products based on 2.6.24, presumably they'd be adding their own > patches anyway, so they could add a trivial prefix change patch too. > (I realise this discussion would have been more useful *before* 2.6.24 > shipped, but I didn't quite get round to it ...) > > A compromise might be to keep "tasks" unprefixed, and say that future > names get the "cgroup." prefix; in this case I'd be inclined to add > the prefix to notify_on_release and release_agent on the grounds that > there's much less chance of breaking anyone with those files since (I > suspect) they're much less used. > > Note that if you mount a cgroup filesystem with the "noprefix" option, > which is what the cpuset filesystem wrapper does, no subsystems have > prefixes, and in this case the "cgroup." prefix wouldn't be used > either. So this doesn't affect any users that explicitly mount cpusets > rather than cgroups. > > Thoughts? > It would be easier to judge if we could see the full directory tree. Because if something is in /foo/bar/cgroup/notify_on_release then prefixing the filename with "cgroup_" seems pretty pointless.