From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762223AbZCaGHH (ORCPT ); Tue, 31 Mar 2009 02:07:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758178AbZCaGGk (ORCPT ); Tue, 31 Mar 2009 02:06:40 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:52451 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761067AbZCaGGj (ORCPT ); Tue, 31 Mar 2009 02:06:39 -0400 Date: Tue, 31 Mar 2009 11:36:07 +0530 From: Balbir Singh To: KAMEZAWA Hiroyuki Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "kosaki.motohiro@jp.fujitsu.com" , "nishimura@mxp.nes.nec.co.jp" Subject: Re: [RFC][PATCH 7/8] memcg soft limit LRU reorder Message-ID: <20090331060607.GH16497@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20090327135933.789729cb.kamezawa.hiroyu@jp.fujitsu.com> <20090327141225.1e483acd.kamezawa.hiroyu@jp.fujitsu.com> <20090330075246.GA16497@balbir.in.ibm.com> <20090331090023.e1d30a5a.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090331090023.e1d30a5a.kamezawa.hiroyu@jp.fujitsu.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * KAMEZAWA Hiroyuki [2009-03-31 09:00:23]: > On Mon, 30 Mar 2009 13:22:46 +0530 > Balbir Singh wrote: > > > * KAMEZAWA Hiroyuki [2009-03-27 14:12:25]: > > > > > From: KAMEZAWA Hiroyuki > > > > > > This patch adds a function to change the LRU order of pages in global LRU > > > under control of memcg's victim of soft limit. > > > > > > FILE and ANON victim is divided and LRU rotation will be done independently. > > > (memcg which only includes FILE cache or ANON can exists.) > > > > > > The routine finds specfied number of pages from memcg's LRU and > > > move it to top of global LRU. They will be the first target of shrink_xxx_list. > > > > This seems to be the core of the patch, but I don't like this very > > much. Moving LRU pages of the mem cgroup seems very subtle, why can't > > we directly use try_to_free_mem_cgroup_pages()? > > > It ignores many things. My concern is that such subtle modification to the global LRU 1. Can break the age property of elements in the LRU (we have mixed ages now in the LRU) 2. Can potentially impact lumpy reclaim, since we've mix LRU pages from the memory controlelr into the global LRU? -- Balbir