From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755530AbYDAGiS (ORCPT ); Tue, 1 Apr 2008 02:38:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751516AbYDAGiJ (ORCPT ); Tue, 1 Apr 2008 02:38:09 -0400 Received: from ausmtp04.au.ibm.com ([202.81.18.152]:41855 "EHLO ausmtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751350AbYDAGiI (ORCPT ); Tue, 1 Apr 2008 02:38:08 -0400 Message-ID: <47F1D576.608@linux.vnet.ibm.com> Date: Tue, 01 Apr 2008 11:55:58 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: YAMAMOTO Takashi CC: menage@google.com, xemul@openvz.org, hugh@veritas.com, skumar@linux.vnet.ibm.com, lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, taka@valinux.co.jp, linux-mm@kvack.org, rientjes@google.com, akpm@linux-foundation.org, kamezawa.hiroyu@jp.fujitsu.com Subject: Re: [RFC][-mm] Add an owner to the mm_struct (v3) References: <20080401054324.829.4517.sendpatchset@localhost.localdomain> <20080401060330.743815A02@siro.lan> In-Reply-To: <20080401060330.743815A02@siro.lan> 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 YAMAMOTO Takashi wrote: >> This patch removes the mem_cgroup member from mm_struct and instead adds >> an owner. This approach was suggested by Paul Menage. The advantage of >> this approach is that, once the mm->owner is known, using the subsystem >> id, the cgroup can be determined. It also allows several control groups >> that are virtually grouped by mm_struct, to exist independent of the memory >> controller i.e., without adding mem_cgroup's for each controller, >> to mm_struct. >> >> A new config option CONFIG_MM_OWNER is added and the memory resource >> controller selects this config option. >> >> NOTE: This patch was developed on top of 2.6.25-rc5-mm1 and is applied on top >> of the memory-controller-move-to-own-slab patch (which is already present >> in the Andrew's patchset). >> >> I am indebted to Paul Menage for the several reviews of this patchset >> and helping me make it lighter and simpler. >> >> This patch was tested on a powerpc box, by running a task under the memory >> resource controller and moving it across groups at a constant interval. >> >> Signed-off-by: Balbir Singh >> --- > > changing mm->owner without notifying controllers makes it difficult to use. > can you provide a notification mechanism? But mm->owner is just a way to get to the correct cgroup and that does not change when mm->owner changes. Do we really need this notification? For the virtual memory controller, move_task() is sufficient, not sure why mm->owner is required. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL