From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752801AbYKYNdb (ORCPT ); Tue, 25 Nov 2008 08:33:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750793AbYKYNdX (ORCPT ); Tue, 25 Nov 2008 08:33:23 -0500 Received: from mx2.redhat.com ([66.187.237.31]:39038 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745AbYKYNdW (ORCPT ); Tue, 25 Nov 2008 08:33:22 -0500 Message-ID: <492BFE6F.5090902@redhat.com> Date: Tue, 25 Nov 2008 08:32:31 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: KOSAKI Motohiro CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mel@csn.ul.ie, akpm@linux-foundation.org Subject: Re: [PATCH] vmscan: bail out of page reclaim after swap_cluster_max pages References: <20081124145057.4211bd46@bree.surriel.com> <20081125203333.26F0.KOSAKI.MOTOHIRO@jp.fujitsu.com> In-Reply-To: <20081125203333.26F0.KOSAKI.MOTOHIRO@jp.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KOSAKI Motohiro wrote: >> 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. Well, the behaviour when priority==DEF_PRIORITY is the same as the kernel's behaviour without the patch... > therefore, I'll try to mesure this patch in this week. Looking forward to it. -- All rights reversed.