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 A1CFF6B005D for ; Tue, 9 Jun 2009 03:55:43 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n598OCUM029472 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 9 Jun 2009 17:24:12 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id D3AF945DD78 for ; Tue, 9 Jun 2009 17:24:11 +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 AF39445DD7E for ; Tue, 9 Jun 2009 17:24:11 +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 8CF9A1DB803E for ; Tue, 9 Jun 2009 17:24:11 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id EFE8A1DB8046 for ; Tue, 9 Jun 2009 17:24:10 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH mmotm] vmscan: handle may_swap more strictly (Re: [PATCH mmotm] vmscan: fix may_swap handling for memcg) In-Reply-To: <28c262360906090119r6e881caq9b74028ba43567a7@mail.gmail.com> References: <20090609164850.DD73.A69D9226@jp.fujitsu.com> <28c262360906090119r6e881caq9b74028ba43567a7@mail.gmail.com> Message-Id: <20090609172035.DD7C.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 9 Jun 2009 17:24:10 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: kosaki.motohiro@jp.fujitsu.com, Daisuke Nishimura , LKML , linux-mm , Andrew Morton , Johannes Weiner , Balbir Singh , KAMEZAWA Hiroyuki List-ID: > On Tue, Jun 9, 2009 at 4:58 PM, KOSAKI > Motohiro wrote: > >> Hi, KOSAKI. > >> > >> As you know, this problem caused by if condition(priority) in shrink_zone. > >> Let me have a question. > >> > >> Why do we have to prevent scan value calculation when the priority is zero ? > >> As I know, before split-lru, we didn't do it. > >> > >> Is there any specific issue in case of the priority is zero ? > > > > Yes. > > > > example: > > > > get_scan_ratio() return anon:80%, file=20%. and the system have > > 10000 anon pages and 10000 file pages. > > > > shrink_zone() picked up 8000 anon pages and 2000 file pages. > > it mean 8000 file pages aren't scanned at all. > > > > Oops, it can makes OOM-killer although system have droppable file cache. > > > Hmm..Can that problem be happen in real system ? > The file ratio is big means that file lru list scanning is so big but > rotate is small. > It means file lru have few reclaimable page. > > Isn't it ? I am confusing. > Could you elaborate, please if you don't mind ? hm, ok, my example was wrong. I intention is, if there are droppable file-back pages (althout only 1 page), OOM-killer shouldn't occuer. many or few is unrelated. -- 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