From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757040AbZKDQZ0 (ORCPT ); Wed, 4 Nov 2009 11:25:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754163AbZKDQZZ (ORCPT ); Wed, 4 Nov 2009 11:25:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36681 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752275AbZKDQZZ (ORCPT ); Wed, 4 Nov 2009 11:25:25 -0500 Message-ID: <4AF1AACE.6060705@redhat.com> Date: Wed, 04 Nov 2009 17:24:46 +0100 From: Jan Safranek User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20091014 Fedora/3.0-2.8.b4.fc11 Lightning/1.0pre Thunderbird/3.0b4 MIME-Version: 1.0 To: "Serge E. Hallyn" CC: Dave Hansen , balbir@linux.vnet.ibm.com, Dhaval Giani , containers@lists.linux-foundation.org, "linux-kernel@vger.kernel.org" , Bharata B Rao , libcg-devel , "menage@google.com" Subject: Re: [RFC] Mount point suggestions for cgroup References: <20091104063005.GC3560@balbir.in.ibm.com> <20091104154024.0b8f6123.kamezawa.hiroyu@jp.fujitsu.com> <20091104081618.GD3560@balbir.in.ibm.com> <1257348117.31972.4360.camel@nimitz> <20091104161142.GA8825@us.ibm.com> In-Reply-To: <20091104161142.GA8825@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/04/2009 05:11 PM, Serge E. Hallyn wrote: > Quoting Dave Hansen (dave@linux.vnet.ibm.com): >> On Wed, 2009-11-04 at 13:46 +0530, Balbir Singh wrote: >>> The reason I liked /dev/cgroup was because cpusets could be >>> mounted at /dev/cpuset or /dev/cgroup/cpuset. My concern with /cgroup >>> is that a ls "/" now becomes larger in size. But I'll take your vote >>> for it as +1 for /cgroup. >> >> /dev/pts is a decent precedent for doing it under /dev, although it does >> deal with actual devices. cgroups do not. > > Hmm, on whose behalf are you making this decision? > > LSB people will want to avoid using /cgroup, LSB (and FHS) IMHO does not specify any place for such stuff: /dev - for devices only, cgroups are not devices /mnt - for admin temporary mounts and "should not affect the manner in which any program is run" /var - for "any unsorted variable data", cgroups are not "unsorted variable data", it's interface to kernel FHS does not specify either /sys and /selinux and it seems to me nobody complains about them. /sys/cgroup would be the best, if sysfs supported mkdir(). But it does not :(. Our kernel guys told me it's relatively easy to create new empty directory /sys/cgroup (or /sys/kernel/cgroup), but it must be compiled into kernel or a module. Then I could mount some tmpfs to it, create /sys/cgroup/cpu, /sys/cgroup/memory etc. and mount the control group hierarchies there... but as you can see, it's really really ugly thing to do. Jan