From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932832Ab2C3Pm6 (ORCPT ); Fri, 30 Mar 2012 11:42:58 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:59083 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753470Ab2C3Pmu (ORCPT ); Fri, 30 Mar 2012 11:42:50 -0400 Date: Fri, 30 Mar 2012 08:42:46 -0700 From: Tejun Heo To: Li Zefan Cc: glommer@parallels.com, lizf@cn.fujitsu.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, rni@google.com, ctalbott@google.com Subject: Re: [PATCHSET] cgroup: cftype based file interface, take #2 Message-ID: <20120330154246.GE28934@google.com> References: <1332368265-21586-1-git-send-email-tj@kernel.org> <4F75AA1F.9020007@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F75AA1F.9020007@huawei.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey, Li. On Fri, Mar 30, 2012 at 08:42:07PM +0800, Li Zefan wrote: > > This patch replaces cgroup file interface with cftype based one which > > allows dynamic additions and removals of cftype arrays whether the > > target subsystem is attached or not. This can be used to make subsys > > rebinding via remount work properly but I intentionally avoided doing > > that at the moment. > > What's the problem with remount? Subsys can't be changed if any non-root cgroup exists. > and is it important enough that it should be fixed even the feature > is marked as deprecated? I'm not sure. We *might* need it during multi-mount -> single-mount transition depending on how that's implemented, so the "at the moment" qualifier. It probably won't be fixed but I'm not fully sure. > > This makes cgroup population simpler for controllers and will be used > > to allow controllers to be more dynamic. e.g. blkio subsys has > > sub-policies which may come and go while blkio subsys is attached and > > it currently uses fixed set of files which stays blank if not in use. > > Dynamic cgroup files was mentioned before. The scenario in mind was blkio > control files can be added/removed automatically as devices come and ago. > > So this time blkio subsystem is really going to be made more dynamic > soon? Patchset already posted. http://thread.gmane.org/gmane.linux.kernel.cgroups/1376 Thanks. -- tejun