From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 69DB16B01F0 for ; Thu, 15 Apr 2010 07:26:13 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o3FBQAa4011794 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 15 Apr 2010 20:26:10 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 151DF45DE4F for ; Thu, 15 Apr 2010 20:26:10 +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 E0C7245DE56 for ; Thu, 15 Apr 2010 20:26:09 +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 CA6D51DB8042 for ; Thu, 15 Apr 2010 20:26:09 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 6E5B71DB8038 for ; Thu, 15 Apr 2010 20:26:09 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 1/4] vmscan: delegate pageout io to flusher thread if current is kswapd In-Reply-To: <20100415103109.GC10966@csn.ul.ie> References: <20100415131106.D174.A69D9226@jp.fujitsu.com> <20100415103109.GC10966@csn.ul.ie> Message-Id: <20100415195227.D1B0.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 15 Apr 2010 20:26:08 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Dave Chinner , Chris Mason , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org List-ID: > On Thu, Apr 15, 2010 at 01:11:37PM +0900, KOSAKI Motohiro wrote: > > Now, vmscan pageout() is one of IO throuput degression source. > > Some IO workload makes very much order-0 allocation and reclaim > > and pageout's 4K IOs are making annoying lots seeks. > > > > At least, kswapd can avoid such pageout() because kswapd don't > > need to consider OOM-Killer situation. that's no risk. > > > > Well, there is some risk here. Direct reclaimers may not be cleaning > more pages than it had to previously except it splices subsystems > together increasing stack usage and causing further problems. > > It might not cause OOM-killer issues but it could increase the time > dirty pages spend on the LRU. > > Am I missing something? No. you are right. I fully agree your previous mail. so, I need to cool down a bit ;) -- 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