Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271005AbUJVJec (ORCPT ); Fri, 22 Oct 2004 05:34:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270908AbUJVJak (ORCPT ); Fri, 22 Oct 2004 05:30:40 -0400 Received: from host213-160-108-25.dsl.vispa.com ([213.160.108.25]:60551 "EHLO cenedra.walrond.org") by vger.kernel.org with ESMTP id S270916AbUJVJ0t (ORCPT ); Fri, 22 Oct 2004 05:26:49 -0400 From: Andrew Walrond To: linux-kernel@vger.kernel.org Subject: Re: lost memory on a 4GB amd64 Date: Fri, 22 Oct 2004 10:26:22 +0100 User-Agent: KMail/1.7 Cc: Sergei Haller , "Rafael J. Wysocki" , Andi Kleen References: <200409241315.42740.andrew@walrond.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200410221026.22531.andrew@walrond.org> X-Spam-Score: 0.0 (/) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1256 Lines: 29 On Friday 22 Oct 2004 09:59, Sergei Haller wrote: > > If I disable NUMA in 2.6.8.1, it works stable! > > The same with 2.6.9, which is out for a few days: if NUMA is disabled, > everything's find, if NUMA is enabled, the kernel crashes (as described in > previous mails) > > What is this NUMA by the way? Is it OK to live without? > Non uniform memory architecture. Basically, some of the ram is attached to cpu1 and some to cpu2. They can still access each others ram using HyperTransport, but can access their own ram faster. I'm no expert, but I guess that the NUMA code tries to achieve persistent process cpu affinity and keep all process memory in the relevant cpu's NUMA ram bank. Or something :) Your board isn't numa, in the sense that all the ram is attached to one cpu, but I don't think that it should break when NUMA is enabled. I've cc'ed Andi Kleen (x86_64 supremo) who might have some insights, but I'm guessing he'll say "Bios problem - tough luck". I might be wrong ;) Andrew Walrond - 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/