From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750722AbZB0FJV (ORCPT ); Fri, 27 Feb 2009 00:09:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751341AbZB0FJK (ORCPT ); Fri, 27 Feb 2009 00:09:10 -0500 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:40030 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751637AbZB0FJJ (ORCPT ); Fri, 27 Feb 2009 00:09:09 -0500 Date: Fri, 27 Feb 2009 10:38:24 +0530 From: Dhaval Giani To: KAMEZAWA Hiroyuki Cc: Andrew Morton , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, menage@google.com, lizf@cn.fujitsu.com, balbir@linux.vnet.ibm.com Subject: Re: [PATCH 1/2] cgroup allow subsys to set default mode of its own file Message-ID: <20090227050823.GA11860@linux.vnet.ibm.com> Reply-To: Dhaval Giani References: <20090225163555.d2a0b24c.kamezawa.hiroyu@jp.fujitsu.com> <20090226130005.3282cb02.akpm@linux-foundation.org> <20090227092031.f42cbbbe.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090227092031.f42cbbbe.kamezawa.hiroyu@jp.fujitsu.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 27, 2009 at 09:20:31AM +0900, KAMEZAWA Hiroyuki wrote: > On Thu, 26 Feb 2009 13:00:05 -0800 > Andrew Morton wrote: > > > On Wed, 25 Feb 2009 16:35:55 +0900 > > KAMEZAWA Hiroyuki wrote: > > > > > When I wrote tools for maintain cgroup, I can't find which file is > > > writable intarfece or not via cgroup file systems. (finally, I did > > > dirty approach.) > > > IMHO, showing "this file is read-only" in explicit way is useful > > > for user-land (tools). In other story, a file whose name sounds read-only > > > may have "trigger" operation and support reseting. In this case, > > > "writable" is informative. > > > > Well, we have compatibility issues here. If we make this change, and > > people write tools which depend upon that change then those tools might > > break when run upon older kernels. Or they need back-compatibility > > additions, which increases the testing burden of those tools. > > > > One way in which we could improve this situation is to backport these > > changes into earlier kernels, although I don't know which versions. > > > > What do we think? > > > It sounds problem to me. > > Hmm..1st commit to kernel/cgroup.c is 2007-10-19, then 2.6.24 is the oldest one. > But I think distro's tools for cgroup is not as old as... > Hmm, backport to 2.6.25 is enough ? > Balbir, how do you think ? I think you are familiar with libcgroup. > I would like to have this backported to at least the distro kernels. thanks, -- regards, Dhaval