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Date: Tue, 20 Apr 2010 13:26:16 +0900
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
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>
Subject: Re: [RFC][BUGFIX][PATCH 2/2] memcg: fix file mapped underflow at
 migration (v3)
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On Tue, 20 Apr 2010 13:20:50 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:

> > > 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.
> 
Ok, look into again.


> > 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.
> 
Maybe I can post v4, today.

Thanks,
-Kame