From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id B12096B01E3 for ; Thu, 15 Apr 2010 04:26:36 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o3F8QXcn014556 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 15 Apr 2010 17:26:33 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 6C9AE45DE4F for ; Thu, 15 Apr 2010 17:26:33 +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 4B52645DE4D for ; Thu, 15 Apr 2010 17:26:33 +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 19CD5E08002 for ; Thu, 15 Apr 2010 17:26:33 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id CB74D1DB8040 for ; Thu, 15 Apr 2010 17:26:28 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 1/4] vmscan: delegate pageout io to flusher thread if current is kswapd In-Reply-To: <20100415171142.D192.A69D9226@jp.fujitsu.com> References: <64BE60A8-EEF9-4AC6-AF0A-0ED3CB544726@freebsd.org> <20100415171142.D192.A69D9226@jp.fujitsu.com> Message-Id: <20100415172215.D19B.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 15 Apr 2010 17:26:27 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Johannes Weiner Cc: kosaki.motohiro@jp.fujitsu.com, Suleiman Souhlal , Dave Chinner , Mel Gorman , Chris Mason , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, suleiman@google.com List-ID: Cc to Johannes > > > > On Apr 14, 2010, at 9:11 PM, 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. > > > > > > Signed-off-by: KOSAKI Motohiro > > > > What's your opinion on trying to cluster the writes done by pageout, > > instead of not doing any paging out in kswapd? > > Something along these lines: > > Interesting. > So, I'd like to review your patch carefully. can you please give me one > day? :) Hannes, if my remember is correct, you tried similar swap-cluster IO long time ago. now I can't remember why we didn't merged such patch. Do you remember anything? > > > > > > Cluster writes to disk due to memory pressure. > > > > Write out logically adjacent pages to the one we're paging out > > so that we may get better IOs in these situations: > > These pages are likely to be contiguous on disk to the one we're > > writing out, so they should get merged into a single disk IO. > > > > Signed-off-by: Suleiman Souhlal > > > > -- 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