From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 539DB6B0044 for ; Wed, 7 Jan 2009 22:46:46 -0500 (EST) Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp05.in.ibm.com (8.13.1/8.13.1) with ESMTP id n083kaOe012917 for ; Thu, 8 Jan 2009 09:16:36 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id n083keYe3391508 for ; Thu, 8 Jan 2009 09:16:40 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id n083kZYa028241 for ; Thu, 8 Jan 2009 14:46:36 +1100 Date: Thu, 8 Jan 2009 09:16:35 +0530 From: Balbir Singh Subject: Re: [RFC][PATCH 0/4] Memory controller soft limit patches Message-ID: <20090108034634.GA7294@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20090107184110.18062.41459.sendpatchset@localhost.localdomain> <20090107185627.GL4145@linux.vnet.ibm.com> <20090108093700.2ad10d85.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090108093700.2ad10d85.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Dhaval Giani , Andrew Morton , Sudhir Kumar , YAMAMOTO Takashi , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Rientjes , Pavel Emelianov List-ID: * KAMEZAWA Hiroyuki [2009-01-08 09:37:00]: > On Thu, 8 Jan 2009 00:26:27 +0530 > Dhaval Giani wrote: > > > On Thu, Jan 08, 2009 at 12:11:10AM +0530, Balbir Singh wrote: > > > > > > Here is v1 of the new soft limit implementation. Soft limits is a new feature > > > for the memory resource controller, something similar has existed in the > > > group scheduler in the form of shares. We'll compare shares and soft limits > > > below. I've had soft limit implementations earlier, but I've discarded those > > > approaches in favour of this one. > > > > > > Soft limits are the most useful feature to have for environments where > > > the administrator wants to overcommit the system, such that only on memory > > > contention do the limits become active. The current soft limits implementation > > > provides a soft_limit_in_bytes interface for the memory controller and not > > > for memory+swap controller. The implementation maintains an RB-Tree of groups > > > that exceed their soft limit and starts reclaiming from the group that > > > exceeds this limit by the maximum amount. > > > > > > This is an RFC implementation and is not meant for inclusion > > > > > > TODOs > > > > > > 1. The shares interface is not yet implemented, the current soft limit > > > implementation is not yet hierarchy aware. The end goal is to add > > > a shares interface on top of soft limits and to maintain shares in > > > a manner similar to the group scheduler > > > > Just to clarify, when there is no contention, you want to share memory > > proportionally? > > > I don't like to add "share" as the kernel interface of memcg. > We used "bytes" to do (hard) limit. Please just use "bytes". > Yes, we'll have soft limit in bytes, but for a hierarchical view, shares do make a lot of sense. The user can use whichever interface suits them the most. -- Balbir -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org