From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: Re: [PATCH 6/7] [RFC] Support multiply-bindable cgroup subsystems Date: Wed, 18 Mar 2009 10:39:27 +0800 Message-ID: <49C05EDF.5010607@cn.fujitsu.com> References: <20090312104507.24154.71691.stgit@menage.corp.google.com> <20090312105147.24154.62638.stgit@menage.corp.google.com> <49BF4744.5060309@cn.fujitsu.com> <49C057EB.1000307@cn.fujitsu.com> <6599ad830903171916x7364ec7cw76975d71d5125d82@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6599ad830903171916x7364ec7cw76975d71d5125d82-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Paul Menage Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: containers.vger.kernel.org Paul Menage wrote: > On Tue, Mar 17, 2009 at 7:09 PM, Li Zefan wrote: >> Ah, I just notice debug_subsys will never be in rootnode. > > Right - this is the first of the "Open Issues" that I mentioned in the > patch. The question is how to display the multiply-bindable subsystems > in /proc/cgroup in a way that won't break backward-compatibility. > Options include: > > - always display one line for each subsystem; if a subsystem is > multiply-bindable then the "hierarchy id" and "num cgroups" columns > may be empty or have multiple (comma or slash-separated?) values > Then "hierarchy id" is no long a single number.. > - for a multiply-bindable subsystem, have a header line to indicate > that the subsystem exists, and then a separate line for each bound > instance of the subsystem. > I think it's better to show every subsystems including debug_subsys in /proc/cgroups, and show exactly n lines of debug_susys if we have n hierarcies with debug_subsys binded, but no header line. > Either of these could confuse existing userspace parsers, but I'm not And some cgroup test programs, like controller tests in ltp and some test programs that I wrote, but they are ok for this change. > sure that any exist other than libcgroup, and I don't think it's in > wide use yet. >