From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx152.postini.com [74.125.245.152]) by kanga.kvack.org (Postfix) with SMTP id B8F1B6B0044 for ; Fri, 9 Mar 2012 17:46:22 -0500 (EST) From: Naoya Horiguchi Subject: Re: [PATCH] memcg: revert fix to mapcount check for this release Date: Fri, 9 Mar 2012 17:46:11 -0500 Message-Id: <1331333171-27972-1-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Linus Torvalds , Andrew Morton , KAMEZAWA Hiroyuki , Daisuke Nishimura , Naoya Horiguchi , Andrea Arcangeli , Hillf Danton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Fri, Mar 09, 2012 at 01:37:32PM -0800, Hugh Dickins wrote: > Respectfully revert commit e6ca7b89dc76 "memcg: fix mapcount check > in move charge code for anonymous page" for the 3.3 release, so that > it behaves exactly like releases 2.6.35 through 3.2 in this respect. > > Horiguchi-san's commit is correct in itself, 1 makes much more sense > than 2 in that check; but it does not go far enough - swapcount > should be considered too - if we really want such a check at all. Agreed. We should rethink whole design rather than detail. > We appear to have reached agreement now, and expect that 3.4 will > remove the mapcount check, but had better not make 3.3 different. > > Signed-off-by: Hugh Dickins Reviewed-by: Naoya Horiguchi > --- > > mm/memcontrol.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- 3.3-rc6+/mm/memcontrol.c 2012-03-05 22:03:45.940000832 -0800 > +++ linux/mm/memcontrol.c 2012-03-09 13:06:41.716250093 -0800 > @@ -5075,7 +5075,7 @@ static struct page *mc_handle_present_pt > return NULL; > if (PageAnon(page)) { > /* we don't move shared anon */ > - if (!move_anon() || page_mapcount(page) > 1) > + if (!move_anon() || page_mapcount(page) > 2) > return NULL; > } else if (!move_file()) > /* we ignore mapcount for file pages */ > > -- > 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/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: email@kvack.org > -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org