Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756144AbZFHOt1 (ORCPT ); Mon, 8 Jun 2009 10:49:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754112AbZFHOtU (ORCPT ); Mon, 8 Jun 2009 10:49:20 -0400 Received: from mx2.redhat.com ([66.187.237.31]:41099 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753866AbZFHOtU (ORCPT ); Mon, 8 Jun 2009 10:49:20 -0400 Message-ID: <4A2D24B0.4080301@redhat.com> Date: Mon, 08 Jun 2009 10:48:16 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: Mel Gorman CC: KOSAKI Motohiro , Christoph Lameter , yanmin.zhang@intel.com, Wu Fengguang , linuxram@us.ibm.com, linux-mm , LKML Subject: Re: [PATCH 1/3] Reintroduce zone_reclaim_interval for when zone_reclaim() scans and fails to avoid CPU spinning at 100% on NUMA References: <1244466090-10711-1-git-send-email-mel@csn.ul.ie> <1244466090-10711-2-git-send-email-mel@csn.ul.ie> <4A2D129D.3020309@redhat.com> <20090608135433.GD15070@csn.ul.ie> In-Reply-To: <20090608135433.GD15070@csn.ul.ie> 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 Content-Length: 1144 Lines: 32 Mel Gorman wrote: > On Mon, Jun 08, 2009 at 09:31:09AM -0400, Rik van Riel wrote: >> Mel Gorman wrote: >> >>> The scanning occurs because zone_reclaim() cannot tell >>> in advance the scan is pointless because the counters do not distinguish >>> between pagecache pages backed by disk and by RAM. >> Yes it can. Since 2.6.27, filesystem backed and swap/ram backed >> pages have been living on separate LRU lists. > > Yes, they're on separate LRU lists but they are not the only pages on those > lists. The tmpfs pages are mixed in together with anonymous pages so we > cannot use NR_*_ANON. > > Look at patch 2 and where I introduced; I have to admit I did not read patches 2 and 3 before replying to the (strange looking, at the time) text above patch 1. With that logic from patch 2 in place, patch 1 makes perfect sense. Acked-by: Rik van Riel -- All rights reversed. -- 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/