From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 21 Aug 2007 09:58:53 +0100 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: From: mel@skynet.ie (Mel Gorman) Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Lee.Schermerhorn@hp.com, ak@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org