From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992533AbXDDDAd (ORCPT ); Tue, 3 Apr 2007 23:00:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992553AbXDDDAd (ORCPT ); Tue, 3 Apr 2007 23:00:33 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:48843 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992533AbXDDDAc (ORCPT ); Tue, 3 Apr 2007 23:00:32 -0400 Date: Wed, 4 Apr 2007 08:37:56 +0530 From: Srivatsa Vaddagiri To: "Paul Menage" Cc: sekharan@us.ibm.com, ckrm-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org, xemul@sw.ru, containers@lists.osdl.org, pj@sgi.com, "Eric W. Biederman" , mbligh@google.com, winget@google.com, rohitseth@google.com, "Serge E. Hallyn" , dev@sw.ru, devel@openvz.org Subject: Re: [ckrm-tech] [PATCH 7/7] containers (V7): Container interface to nsproxy subsystem Message-ID: <20070404030756.GA9008@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20070403153220.GA24946@sergelap.austin.ibm.com> <6599ad830704030845p654cf8dh65ccdc46c92d3688@mail.gmail.com> <20070403164615.GJ2456@in.ibm.com> <6599ad830704030952r5c295f3ap6e366de31dab2ccb@mail.gmail.com> <20070403171155.GK2456@in.ibm.com> <6599ad830704031010i5418abf1o12b11334cde4d2c5@mail.gmail.com> <20070403173048.GL2456@in.ibm.com> <6599ad830704031030n2311bcd7hca9f34e64c66337f@mail.gmail.com> <20070403175101.GN2456@in.ibm.com> <6599ad830704031049v7fad0a83q3c24211cf44d71d6@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6599ad830704031049v7fad0a83q3c24211cf44d71d6@mail.gmail.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 03, 2007 at 10:49:49AM -0700, Paul Menage wrote: > > Why is the hierarchy bit important here? Usually controllers need to > > know "tell me what cpuset this task belongs to", which is answered > > by tsk->nsproxy->ctlr_data[CPUSET_ID]. > > I was thinking of queries from userspace. User space queries like "what is the cpuset to which this task belongs", where the answer needs to be something of the form "/dev/cpuset/C1"? The patches address that requirement atm by having a dentry pointer in struct cpuset itself. Do you see similar queries coming in for every resource controller object (show me the path of cpu_acct, cpu_ctl, rss_ctl ... objects to which this task belongs)? IMO that will not be the case, in which case we can avoid adding N pointers (N = max hierarchies) in nsproxy just to support queries of those sort. If additional resource objects need to support such queries in future, we could add a dentry pointer in those objects as and when the need arises. -- Regards, vatsa