From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261590AbVHBPqZ (ORCPT ); Tue, 2 Aug 2005 11:46:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261581AbVHBPoT (ORCPT ); Tue, 2 Aug 2005 11:44:19 -0400 Received: from dvhart.com ([64.146.134.43]:8891 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S261587AbVHBPnx (ORCPT ); Tue, 2 Aug 2005 11:43:53 -0400 Date: Tue, 02 Aug 2005 08:43:50 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" To: Sonny Rao , Paul Mackerras Cc: torvalds@osdl.org, akpm@osdl.org, anton@samba.org, Mike Kravetz , linux-kernel@vger.kernel.org Subject: Re: [PATCH] POWER 4 fails to boot with NUMA Message-ID: <1980000.1122997430@[10.10.2.4]> In-Reply-To: <20050801062322.GA32415@kevlar.burdell.org> References: <17133.45774.226079.790875@cargo.ozlabs.ibm.com> <20050801062322.GA32415@kevlar.burdell.org> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --Sonny Rao wrote (on Monday, August 01, 2005 02:23:22 -0400): > On Mon, Aug 01, 2005 at 12:27:42AM -0500, Paul Mackerras wrote: >> From: Mike Kravetz >> >> If CONFIG_NUMA is set, some POWER 4 systems will fail to boot. This is >> because of special processing needed to handle invalid node IDs (0xffff) >> on POWER 4. My previous patch to handle memory 'holes' within nodes >> forgot to add this special case for POWER 4 in one place. >> >> In reality, I'm not sure that configuring the kernel for NUMA on POWER 4 >> makes much sense. Are there POWER 4 based systems with NUMA characteristics >> that are presented by the firmware? But, distros want one kernel for all >> systems so NUMA is on by default in their kernels. The patch handles those >> cases. > > IIRC, In SMP mode the NUMA topology is exported. I've tried this on a > p690 and it worked correctly on older kernels (2.6.10 or 2.6.11) > > I also noticed a nice speedup on a few things compared to LPAR mode :-) Yeah, I have a p650 that's set up similarly .... I thought the auto-test stuff was covering that, but it seems NUMA is not turned on for that box like I thought it was. will fix .... M.