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 489926B01E3 for ; Thu, 15 Apr 2010 00:35:22 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o3F4ZJug007996 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 15 Apr 2010 13:35:19 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 1F5E245DE52 for ; Thu, 15 Apr 2010 13:35:19 +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 004E545DE51 for ; Thu, 15 Apr 2010 13:35:19 +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 D0A141DB8037 for ; Thu, 15 Apr 2010 13:35:18 +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 87CBC1DB803B for ; Thu, 15 Apr 2010 13:35:18 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] mm: disallow direct reclaim page writeback In-Reply-To: <20100415130212.D16E.A69D9226@jp.fujitsu.com> References: <20100415013436.GO2493@dastard> <20100415130212.D16E.A69D9226@jp.fujitsu.com> Message-Id: <20100415133332.D183.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Date: Thu, 15 Apr 2010 13:35:17 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Dave Chinner Cc: kosaki.motohiro@jp.fujitsu.com, Mel Gorman , Chris Mason , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org List-ID: > Hi > > > How about this? For now, we stop direct reclaim from doing writeback > > only on order zero allocations, but allow it for higher order > > allocations. That will prevent the majority of situations where > > direct reclaim blows the stack and interferes with background > > writeout, but won't cause lumpy reclaim to change behaviour. > > This reduces the scope of impact and hence testing and validation > > the needs to be done. > > Tend to agree. but I would proposed slightly different algorithm for > avoind incorrect oom. > > for high order allocation > allow to use lumpy reclaim and pageout() for both kswapd and direct reclaim > > for low order allocation > - kswapd: always delegate io to flusher thread > - direct reclaim: delegate io to flusher thread only if vm pressure is low > > This seems more safely. I mean Who want see incorrect oom regression? > I've made some pathes for this. I'll post it as another mail. Now, kernel compile and/or backup operation seems keep nr_vmscan_write==0. Dave, can you please try to run your pageout annoying workload? -- 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