From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 127BA6B02AA for ; Wed, 28 Jul 2010 10:17:13 -0400 (EDT) Date: Wed, 28 Jul 2010 10:17:05 -0400 From: Vivek Goyal Subject: Re: [RFC][PATCH 4/7][memcg] memcg use ID in page_cgroup Message-ID: <20100728141705.GA16314@redhat.com> References: <20100727165155.8b458b7f.kamezawa.hiroyu@jp.fujitsu.com> <20100727165629.6f98145c.kamezawa.hiroyu@jp.fujitsu.com> <20100728023904.GE12642@redhat.com> <20100728114402.571b8ec6.kamezawa.hiroyu@jp.fujitsu.com> <20100728031358.GG12642@redhat.com> <20100728121820.0475142a.kamezawa.hiroyu@jp.fujitsu.com> <20100728122128.411f2128.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100728122128.411f2128.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , gthelen@google.com, m-ikeda@ds.jp.nec.com, "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" List-ID: On Wed, Jul 28, 2010 at 12:21:28PM +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 28 Jul 2010 12:18:20 +0900 > KAMEZAWA Hiroyuki wrote: > > > > > Hmm, but page-allocation-time doesn't sound very good for me. > > > > > > > > > > Why? > > > > > > > As you wrote, by attaching ID when a page cache is added, we'll have > > much chances of free-rider until it's paged out. So, adding some > > reseting-owner point may be good. > > > > But considering real world usage, I may be wrong. > > There will not be much free rider in real world, especially at write(). > > Then, page-allocation time may be good. > > > > (Because database doesn't use page-cache, there will be no big random write > > application.) > > > > Sorry, one more reason. memory cgroup has much complex code for supporting > move_account, re-attaching memory cgroup per pages. > So, if you take care of task-move-between-groups, blkio-ID may have > some problems if you only support allocation-time accounting. I think initially we can just keep it simple for blkio controller and not move page charges across blkio cgroup when process moves. Vivek -- 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