Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756636AbYHUDwi (ORCPT ); Wed, 20 Aug 2008 23:52:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755189AbYHUDw2 (ORCPT ); Wed, 20 Aug 2008 23:52:28 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:45695 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754082AbYHUDw1 (ORCPT ); Wed, 20 Aug 2008 23:52:27 -0400 Date: Thu, 21 Aug 2008 12:58:42 +0900 From: KAMEZAWA Hiroyuki To: balbir@linux.vnet.ibm.com Cc: LKML , "yamamoto@valinux.co.jp" , "nishimura@mxp.nes.nec.co.jp" , ryov@valinux.co.jp, "linux-mm@kvack.org" Subject: Re: [RFC][PATCH -mm 0/7] memcg: lockless page_cgroup v1 Message-Id: <20080821125842.7a8a073e.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <48ACE2D5.8090106@linux.vnet.ibm.com> References: <20080819173014.17358c17.kamezawa.hiroyu@jp.fujitsu.com> <20080820185306.e897c512.kamezawa.hiroyu@jp.fujitsu.com> <20080820194108.e76b20b3.kamezawa.hiroyu@jp.fujitsu.com> <20080820200006.a152c14c.kamezawa.hiroyu@jp.fujitsu.com> <20080821111740.49f99038.kamezawa.hiroyu@jp.fujitsu.com> <48ACE2D5.8090106@linux.vnet.ibm.com> Organization: Fujitsu X-Mailer: Sylpheed 2.4.2 (GTK+ 2.10.11; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1676 Lines: 42 On Thu, 21 Aug 2008 09:06:53 +0530 Balbir Singh wrote: > > I'd like to rewrite force_empty to move all usage to "default" cgroup. > > There are some reasons. > > > > 1. current force_empty creates an alive page which has no page_cgroup. > > This is bad for routine which want to access page_cgroup from page. > > And this behavior will be an issue of race condition in future. > > 2. We can see amount of out-of-control usage in default cgroup. > > > > But to do this, I'll have to avoid "hitting limit" in default cgroup. > > I'm now wondering to make it impossible to set limit to default cgroup. > > (will show as a patch in the next version of series.) > > Does anyone have an idea ? > > > > Hi, Kamezawa-San, > > The definition of default-cgroup would be root cgroup right? I would like to > implement hierarchies correctly in order to define the default-cgroup (it could > be a parent of the child cgroup for example). > Ah yes, "root" cgroup, now. I need trash-can-cgroup somewhere for force_empty. Accounted-in-trash-can is better than accounter by no one. Once we change the behavior, we can have another choices of improvements. 1. move account information to the parent cgroup. 2. move account information to user-defined trash-can cgroup. As first step, I'd like to start from "root" cgroup. We can improve behavior in step-by-step manner as we've done. Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/