Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757758AbXHUI7K (ORCPT ); Tue, 21 Aug 2007 04:59:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752958AbXHUI64 (ORCPT ); Tue, 21 Aug 2007 04:58:56 -0400 Received: from gir.skynet.ie ([193.1.99.77]:35891 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752210AbXHUI6z (ORCPT ); Tue, 21 Aug 2007 04:58:55 -0400 Date: Tue, 21 Aug 2007 09:58:53 +0100 To: Christoph Lameter Cc: Lee.Schermerhorn@hp.com, ak@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 4/6] Record how many zones can be safely skipped in the zonelist Message-ID: <20070821085853.GD29794@skynet.ie> References: <20070817201647.14792.2690.sendpatchset@skynet.skynet.ie> <20070817201808.14792.13501.sendpatchset@skynet.skynet.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) From: mel@skynet.ie (Mel Gorman) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1018 Lines: 24 On (17/08/07 14:03), Christoph Lameter didst pronounce: > Is there any performance improvement because of this patch? It looks > like processing got more expensive since an additional cacheline needs to > be fetches to get the skip factor. > It's a small gain on a few machines. Where I thought it was more likely to be a win is on x86-64 NUMA machines particularly if the zonelist ordering was zone order as there would be potentially many nodes to skip. Kernbench didn't show up any regressions for the other machines but the userspace portion of that workload is unlikely to notice the loss of a cache line. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - 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/