From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752308AbXDZQ3k (ORCPT ); Thu, 26 Apr 2007 12:29:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754831AbXDZQ3j (ORCPT ); Thu, 26 Apr 2007 12:29:39 -0400 Received: from atlrel7.hp.com ([156.153.255.213]:37700 "EHLO atlrel7.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752308AbXDZQ3i (ORCPT ); Thu, 26 Apr 2007 12:29:38 -0400 Subject: Re: [PATCH] change global zonelist order on NUMA v3 From: Lee Schermerhorn To: Christoph Lameter Cc: KAMEZAWA Hiroyuki , ak@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, Eric Whitney In-Reply-To: References: <20070426183417.058f6f9e.kamezawa.hiroyu@jp.fujitsu.com> <200704261147.44413.ak@suse.de> <20070426191043.df96c114.kamezawa.hiroyu@jp.fujitsu.com> <20070426195348.6a4e5652.kamezawa.hiroyu@jp.fujitsu.com> <1177603203.5705.36.camel@localhost> Content-Type: text/plain Organization: HP/OSLO Date: Thu, 26 Apr 2007 12:29:22 -0400 Message-Id: <1177604962.5705.55.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2007-04-26 at 09:06 -0700, Christoph Lameter wrote: > Hmmmm... One additional easy way to fix this would be to create a DMA > node and place it very distant to other nodes. This would make it a > precious system resource that is only used for > > 1. GFP_DMA allocations > > 2. If the memory on the other nodes is exhausted. > This would solve the problem for "100% CLM" configurations where the only thing in the interleaved pseudo-node is DMA zone. However, we can configure any %-age of CLM between 0% [fully interleaved, pseudo-SMP] and "100%" [which is not really, as I've mentioned]. Interestingly, older revs of our firmware set the SLIT distance for the interleaved pseudo-node to 255 [or such], so it was always last. Then someone decided that the interleaved node was effectively closer than other nodes... I have been considering an HP-platform-specific boot option [handled by a new ia64 machine vec op] to re-distance the interleaved node, but for other platforms, such as Kame's, I think we still need the ability to move the DMA zones last in the Normal zone lists. Or, exclude them altogether? Lee