From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753411AbYKYLf1 (ORCPT ); Tue, 25 Nov 2008 06:35:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750828AbYKYLfR (ORCPT ); Tue, 25 Nov 2008 06:35:17 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:38368 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbYKYLfP (ORCPT ); Tue, 25 Nov 2008 06:35:15 -0500 From: KOSAKI Motohiro To: Rik van Riel Subject: Re: [PATCH] vmscan: bail out of page reclaim after swap_cluster_max pages Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mel@csn.ul.ie, akpm@linux-foundation.org In-Reply-To: <20081124145057.4211bd46@bree.surriel.com> References: <20081124145057.4211bd46@bree.surriel.com> Message-Id: <20081125203333.26F0.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Date: Tue, 25 Nov 2008 20:35:12 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Sometimes the VM spends the first few priority rounds rotating back > referenced pages and submitting IO. Once we get to a lower priority, > sometimes the VM ends up freeing way too many pages. > > The fix is relatively simple: in shrink_zone() we can check how many > pages we have already freed, direct reclaim tasks break out of the > scanning loop if they have already freed enough pages and have reached > a lower priority level. > > However, in order to do this we do need to know how many pages we already > freed, so move nr_reclaimed into scan_control. > > Signed-off-by: Rik van Riel > --- > Kosaki, this should address the zone scanning pressure issue. hmmmm. I still don't like the behavior when priority==DEF_PRIORITY. but I also should explain by code and benchmark. therefore, I'll try to mesure this patch in this week. thanks.