Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964997AbVLFSJX (ORCPT ); Tue, 6 Dec 2005 13:09:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964996AbVLFSJX (ORCPT ); Tue, 6 Dec 2005 13:09:23 -0500 Received: from cantor2.suse.de ([195.135.220.15]:2195 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S964992AbVLFSJW (ORCPT ); Tue, 6 Dec 2005 13:09:22 -0500 Date: Tue, 6 Dec 2005 19:09:20 +0100 From: Andi Kleen To: Christoph Lameter Cc: Andi Kleen , akpm@osdl.org, Christoph Hellwig , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, torvalds@osdl.org Subject: Re: [PATCH 1/2] Zone reclaim V2 Message-ID: <20051206180920.GR11190@wotan.suse.de> References: <20051206172444.18786.30131.sendpatchset@schroedinger.engr.sgi.com> <20051206175256.GO11190@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1429 Lines: 31 On Tue, Dec 06, 2005 at 10:01:28AM -0800, Christoph Lameter wrote: > On Tue, 6 Dec 2005, Andi Kleen wrote: > > > > An arch can control zone_reclaim by setting zone_reclaim_mode during bootup > > > if it is discovered that the kernel is running on an NUMA configuration. > > > > Looks much better. Thanks. But how about auto controlling the variable in generic > > code based on node_distance() (at least for the non node hotplug case) > > Any suggestions on how to determine zone reclaim behavior based on node > distances? AFAIK the main aspects in this are latency and bandwidth of > remote accesses. These vary depending on the distance of the remote node > under consideration. I would enable it if distance for any combination of online (or possible?) nodes is > LOCAL_DISTANCE. I guess hotplug can be ignored for now. If an architecture really needs something better it can be still refined. But there aren't that many NUMA architectures anyways, so it shouldn't be a big issue. It will actually need some tweaking on Opterons because many BIOS just report 10 everywhere in SLIT and it should be still enabled, but that can be done in the architecture then. -Andi - 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/