From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 875476B0201 for ; Thu, 15 Apr 2010 04:17:45 -0400 (EDT) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o3F8HgPF014385 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 15 Apr 2010 17:17:42 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id BC8C645DE58 for ; Thu, 15 Apr 2010 17:17:38 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 8D8FF45DE56 for ; Thu, 15 Apr 2010 17:17:38 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id C4B1E1DB805E for ; Thu, 15 Apr 2010 17:17:37 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 63A4E1DB8038 for ; Thu, 15 Apr 2010 17:17:34 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 1/4] vmscan: delegate pageout io to flusher thread if current is kswapd In-Reply-To: <64BE60A8-EEF9-4AC6-AF0A-0ED3CB544726@freebsd.org> References: <20100415131106.D174.A69D9226@jp.fujitsu.com> <64BE60A8-EEF9-4AC6-AF0A-0ED3CB544726@freebsd.org> Message-Id: <20100415171142.D192.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 15 Apr 2010 17:17:33 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Suleiman Souhlal Cc: kosaki.motohiro@jp.fujitsu.com, 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: > > 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? :) > > 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