From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id DB4116B0207 for ; Tue, 30 Mar 2010 00:56:07 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o2U4u4L8011746 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 30 Mar 2010 13:56:04 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id A74CC45DE55 for ; Tue, 30 Mar 2010 13:56:03 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 8351B45DE4E for ; Tue, 30 Mar 2010 13:56:03 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 5866BE38002 for ; Tue, 30 Mar 2010 13:56:03 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id EDE851DB804C for ; Tue, 30 Mar 2010 13:56:02 +0900 (JST) Date: Tue, 30 Mar 2010 13:51:59 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH(v2) -mmotm 2/2] memcg move charge of shmem at task migration Message-Id: <20100330135159.025b9366.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100330130648.ad559645.nishimura@mxp.nes.nec.co.jp> References: <20100329120243.af6bfeac.nishimura@mxp.nes.nec.co.jp> <20100329120359.1c6a277d.nishimura@mxp.nes.nec.co.jp> <20100329133645.e3bde19f.kamezawa.hiroyu@jp.fujitsu.com> <20100330103301.b0d20f7e.nishimura@mxp.nes.nec.co.jp> <20100330112301.f5bb49d7.kamezawa.hiroyu@jp.fujitsu.com> <20100330114903.476af77e.nishimura@mxp.nes.nec.co.jp> <20100330121119.fcc7d45b.kamezawa.hiroyu@jp.fujitsu.com> <20100330130648.ad559645.nishimura@mxp.nes.nec.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: linux-mm , Andrew Morton , Balbir Singh List-ID: On Tue, 30 Mar 2010 13:06:48 +0900 Daisuke Nishimura wrote: > On Tue, 30 Mar 2010 12:11:19 +0900, KAMEZAWA Hiroyuki wrote: > > On Tue, 30 Mar 2010 11:49:03 +0900 > > Daisuke Nishimura wrote: > > > > > On Tue, 30 Mar 2010 11:23:01 +0900, KAMEZAWA Hiroyuki wrote: > > > > SHARED mapped file cache is not moved by patch [1/2] ??? > > > > It sounds strange. > > > > > > > hmm, I'm sorry I'm not so good at user applications, but is it usual to use > > > VM_SHARED file caches(!tmpfs) ? > > > And is it better for us to move them only when page_mapcount() == 1 ? > > > > > > > Considering shared library which has only one user, moving MAP_SHARED makes sense. > > Unfortunately, there are people who creates their own shared library just for > > their private dlopen() etc. (shared library for private use...) > > > > So, I think moving MAP_SHARED files makes sense. > > > Thank you for your explanations. > I'll update my patches to allow to move MAP_SHARED(but page_mapcount() == 1) > file caches, and resend. > Hmm, considering again...current summary is following...right ? - If page is an anon, it's not moved if page_mapcount() > 2. - If page is a page cache, it's not moved if page_mapcount() > 2. - If page is a shmem, it's not moved regardless of mapcount. - If pte is swap, it's not moved refcnt > 2. I think following is straightforward and simple. - If page is an anon or swap of anon, it's not moved if referer > 2. (i.e. inherited from it's parent) - If page is file,shmem or swap of shmem, it's moved regardless of referer. But pages only under "from" memcg can be moved. I doubt adding too much speciality to shmem is not good. How do you think ? 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