From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <owner-linux-mm@kvack.org>
Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227])
	by kanga.kvack.org (Postfix) with ESMTP id 87DB96B01EF
	for <linux-mm@kvack.org>; Tue, 20 Apr 2010 00:22:55 -0400 (EDT)
Date: Tue, 20 Apr 2010 13:20:50 +0900
From: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Subject: Re: [RFC][BUGFIX][PATCH 2/2] memcg: fix file mapped underflow at
 migration (v3)
Message-Id: <20100420132050.3477a717.nishimura@mxp.nes.nec.co.jp>
In-Reply-To: <20100419172629.dbf65e18.kamezawa.hiroyu@jp.fujitsu.com>
References: <20100413134207.f12cdc9c.nishimura@mxp.nes.nec.co.jp>
	<20100415120516.3891ce46.kamezawa.hiroyu@jp.fujitsu.com>
	<20100415120652.c577846f.kamezawa.hiroyu@jp.fujitsu.com>
	<20100416193143.5807d114.kamezawa.hiroyu@jp.fujitsu.com>
	<20100419124225.91f3110b.nishimura@mxp.nes.nec.co.jp>
	<20100419131817.f263d93c.kamezawa.hiroyu@jp.fujitsu.com>
	<20100419170701.3864992e.nishimura@mxp.nes.nec.co.jp>
	<20100419172629.dbf65e18.kamezawa.hiroyu@jp.fujitsu.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: owner-linux-mm@kvack.org
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: LKML <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>, Mel Gorman <mel@csn.ul.ie>, Rik van Riel <riel@redhat.com>, Minchan Kim <minchan.kim@gmail.com>, Balbir Singh <balbir@linux.vnet.ibm.com>, KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>, Christoph Lameter <cl@linux-foundation.org>, Andrea Arcangeli <aarcange@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
List-ID: <linux-mm.kvack.org>

> > I have one concern for now. Reading the patch, the flag have influence on
> > only anonymous pages, so we'd better to note it and I feel it strange to
> > set(and clear) the flag of "old page" always(iow, even when !PageAnon)
> > in prepare_migration.
> > 
> 
> Hmm...Checking "Only Anon" is simpler ?
I just thought it was inconsistent that we always set/clear the bit about "old page",
while we set the bit about "new page" only in PageAnon case.

> It will have no meanings for migrating
> file caches, but it may have some meanings for easy debugging. 
> I think "mark it always but it's used only for anonymous page" is reasonable
> (if it causes no bug.)
> 
Anyway, I don't have any strong objection.
It's all right for me as long as it is well documented or commented.


Thanks,
Daisuke Nishimura.

--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>