Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754637Ab0DOIRm (ORCPT ); Thu, 15 Apr 2010 04:17:42 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:57286 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751256Ab0DOIRi (ORCPT ); Thu, 15 Apr 2010 04:17:38 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Suleiman Souhlal Subject: Re: [PATCH 1/4] vmscan: delegate pageout io to flusher thread if current is kswapd 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 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 X-Mailer: Becky! ver. 2.50.07 [ja] Date: Thu, 15 Apr 2010 17:17:33 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1349 Lines: 39 > > 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/