From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id D400C60021B for ; Sun, 27 Dec 2009 22:18:42 -0500 (EST) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id nBS3IdK6028639 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Mon, 28 Dec 2009 12:18:40 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id AB4CE45DE50 for ; Mon, 28 Dec 2009 12:18:39 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 88C7745DE4F for ; Mon, 28 Dec 2009 12:18:39 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id E7AD81DB803F for ; Mon, 28 Dec 2009 12:18:38 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 9C11D1DB8037 for ; Mon, 28 Dec 2009 12:18:38 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH -mmotm-2009-12-10-17-19] Prevent churning of zero page in LRU list. In-Reply-To: <20091228115315.76b1ecd0.minchan.kim@barrios-desktop> References: <20091228115315.76b1ecd0.minchan.kim@barrios-desktop> Message-Id: <20091228121758.A67E.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Mon, 28 Dec 2009 12:18:38 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , lkml , linux-mm , Hugh Dickins , Rik van Riel List-ID: > > VM doesn't add zero page to LRU list. > It means zero page's churning in LRU list is pointless. > > As a matter of fact, zero page can't be promoted by mark_page_accessed > since it doesn't have PG_lru. > > This patch prevent unecessary mark_page_accessed call of zero page > alghouth caller want FOLL_TOUCH. > > Signed-off-by: Minchan Kim Looks good to me. Reviewed-by: KOSAKI Motohiro -- 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