From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756112AbZBWCz6 (ORCPT ); Sun, 22 Feb 2009 21:55:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752862AbZBWCzt (ORCPT ); Sun, 22 Feb 2009 21:55:49 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:58446 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752652AbZBWCzt (ORCPT ); Sun, 22 Feb 2009 21:55:49 -0500 Message-ID: <49A21044.40402@cn.fujitsu.com> Date: Mon, 23 Feb 2009 10:56:04 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: KAMEZAWA Hiroyuki CC: "linux-kernel@vger.kernel.org" , menage@google.com, containers@lists.linux-foundation.org Subject: Re: Question for remount References: <20090220190223.e8b4f6a8.kamezawa.hiroyu@jp.fujitsu.com> <49A20976.2050301@cn.fujitsu.com> In-Reply-To: <49A20976.2050301@cn.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Li Zefan wrote: >> 1. Documentation/cgroups/cgroup.txt says >> #mount -oremount,cpuset,ns /dev/cgroup >> But this should be >> #mount -tcgroup none /dev/cgroup -oremount,cpuset,ns >> > > I agree. Actually I noticed this long ago. > > Doing this won't remove cpuacct from the cgroup hierarchy: > # mount -t cgroup -o cpu,cpuacct xxx /mnt > # mount -o remount,cpu /mnt > This will get you right: > # mount [-t cgroup] -o remount,cpu xxx /mnt > How about this patch: [PATCH] cgroups: fix documentation about remount This won't remove cpuacct from the mounted hierachy: # mount -t cgroup -o cpu,cpuacct xxx /mnt # mount -o remount,cpu /mnt Because for this usage mount(8) will append the new options to the current options. And this will get you right: # mount [-t cgroup] -o remount,cpu xxx /mnt Signed-off-by: Li Zefan --- Documentation/cgroups/cgroups.txt | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 93feb84..5cbeab2 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -337,8 +337,13 @@ subsystems, type: To change the set of subsystems bound to a mounted hierarchy, just remount with different options: +# mount -o remount,cpuset,ns hier1 /dev/cgroup -# mount -o remount,cpuset,ns /dev/cgroup +Now numtasks is removed from the hierarchy and ns is added. + +Note this will add ns to the hierarchy but won't remove numtasks or +cpuset: +# mount -o remount,ns /dev/cgroup Note that changing the set of subsystems is currently only supported when the hierarchy consists of a single (root) cgroup. Supporting -- 1.5.4.rc3