From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 238316B003D for ; Tue, 31 Mar 2009 02:20:43 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n2V6KvLH014719 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 31 Mar 2009 15:20:58 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 9003445DE57 for ; Tue, 31 Mar 2009 15:20:57 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 6801345DE5D for ; Tue, 31 Mar 2009 15:20:57 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 26847E18006 for ; Tue, 31 Mar 2009 15:20:57 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id AFD161DB8040 for ; Tue, 31 Mar 2009 15:20:56 +0900 (JST) Date: Tue, 31 Mar 2009 15:19:29 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 7/8] memcg soft limit LRU reorder Message-Id: <20090331151929.3d958a95.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090331060607.GH16497@balbir.in.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> <20090331060607.GH16497@balbir.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "kosaki.motohiro@jp.fujitsu.com" , "nishimura@mxp.nes.nec.co.jp" List-ID: On Tue, 31 Mar 2009 11:36:07 +0530 Balbir Singh wrote: > * 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 > okay. maybe everyone's concern. > 1. Can break the age property of elements in the LRU (we have mixed > ages now in the LRU) We have to break(change) some, anyway. I think this kind of LRU-swapping/reorder technique is a popular technique to give LRU a hint and reordering is one of the least invasive options. It doesn't affect global LRU other than the order of pages and all statistics are updated in sane way. > 2. Can potentially impact lumpy reclaim, since we've mix LRU pages > from the memory controlelr into the global LRU? > I can't catch what you ask...but I think no influence to lumpty reclaim. It gathers vicitm pages from neiborhood of a page which should be removed. Hmm ? Thanks, -Kame -- 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