From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx119.postini.com [74.125.245.119]) by kanga.kvack.org (Postfix) with SMTP id C4B106B0044 for ; Fri, 9 Mar 2012 16:38:02 -0500 (EST) Received: by iajr24 with SMTP id r24so3781538iaj.14 for ; Fri, 09 Mar 2012 13:38:02 -0800 (PST) Date: Fri, 9 Mar 2012 13:37:32 -0800 (PST) From: Hugh Dickins Subject: [PATCH] memcg: revert fix to mapcount check for this release In-Reply-To: Message-ID: References: <1330719189-20047-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1330719189-20047-2-git-send-email-n-horiguchi@ah.jp.nec.com> <20120309101658.8b36ce4f.kamezawa.hiroyu@jp.fujitsu.com> <20120309122448.92931dc6.kamezawa.hiroyu@jp.fujitsu.com> <20120309150109.51ba8ea1.nishimura@mxp.nes.nec.co.jp> <20120309162357.71c8c573.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Andrew Morton , KAMEZAWA Hiroyuki , Daisuke Nishimura , Naoya Horiguchi , Andrea Arcangeli , Hillf Danton , linux-kernel@vger.kernel.org, linux-mm@kvack.org 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. 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 --- 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