From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261517AbVFMX4I (ORCPT ); Mon, 13 Jun 2005 19:56:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261484AbVFMXyn (ORCPT ); Mon, 13 Jun 2005 19:54:43 -0400 Received: from mxsf25.cluster1.charter.net ([209.225.28.225]:63460 "EHLO mxsf25.cluster1.charter.net") by vger.kernel.org with ESMTP id S261500AbVFMXwR (ORCPT ); Mon, 13 Jun 2005 19:52:17 -0400 X-IronPort-AV: i="3.93,196,1115006400"; d="scan'208"; a="1004645416:sNHT31109864" From: Jacob Martin Reply-To: martin@cs.uga.edu Organization: University of Georgia To: Andi Kleen Subject: Re: PROBLEM: OOPSes in PREEMPT SMP for AMD Opteron Dual-Core with Memhole Mapping (non tainted kernel) Date: Mon, 13 Jun 2005 19:53:16 +0000 User-Agent: KMail/1.8 Cc: linux-kernel@vger.kernel.org References: <200506071836.12076.martin@cs.uga.edu> <200506121529.50259.martin@cs.uga.edu> <20050613100604.GA18976@muc.de> In-Reply-To: <20050613100604.GA18976@muc.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200506131953.16958.martin@cs.uga.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Monday 13 June 2005 10:06 am, Andi Kleen wrote: > On Sun, Jun 12, 2005 at 03:29:50PM -0400, Jacob Martin wrote: > > Hardware memhole mapping never seems to work, or causes lockups right > > away. I need to test it further though. > > > > I have discovered that with the following features enabled: > > > > 1. Software memhole mapping > > 2. Continuous, > > > > linux sees the entire 4GB of memory. However, when things start getting > > requested from the upper half, there are Oopses generated. Attached are > > two Oopses that occurred under the test scenario described. > > What happens when you boot with numa=off or with numa=noacpi ? You got it! It seems to be working just fine without it compiled into the kernel. > The system seems to believe it has memory in an area not covered > by mem_map. I think you hit it right on the head. I enabled NUMA because I had anticipated upgrading later. So I guess if you don't actually have NUMA set up hardware-wise, and enable this module, then you will have problems. Maybe a simple update to the kernel "K8 NUMA support" Processor feature's help section should be made to note this? Or, is there something that could be fixed somewhere. I wouldn't mind helping, it was baffling me for two weeks. > > launch big memory apps. > > > > I suppose I could write a program to consume/probe the upper memory half. > > Anyone know of a good/quicky way to do that? > > You can use the attached program which I often use for similar purposes. > It writes nearly all free memory in a loop and also often triggers memory > problems. Thanks for that too! Sincerely, Jacob Martin -- Jacob Martin