Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932546AbXARWAT (ORCPT ); Thu, 18 Jan 2007 17:00:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932555AbXARWAT (ORCPT ); Thu, 18 Jan 2007 17:00:19 -0500 Received: from mx1.redhat.com ([66.187.233.31]:56535 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932546AbXARWAR (ORCPT ); Thu, 18 Jan 2007 17:00:17 -0500 Date: Thu, 18 Jan 2007 16:57:22 -0500 (EST) From: Chip Coldwell To: Andi Kleen cc: Chris Wedgwood , Christoph Anton Mitterer , Robert Hancock , linux-kernel@vger.kernel.org, knweiss@gmx.de, andersen@codepoet.org, krader@us.ibm.com, lfriedman@nvidia.com, linux-nforce-bugs@nvidia.com Subject: Re: data corruption with nvidia chipsets and IDE/SATA drives (k8 cpu errata needed?) In-Reply-To: <200701180915.32944.ak@suse.de> Message-ID: References: <200701170829.54540.ak@suse.de> <200701180915.32944.ak@suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1184 Lines: 35 On Thu, 18 Jan 2007, Andi Kleen wrote: > > The Northbridge guarantees coherency over the aperture, but > only if the caching attributes match. That's interesting. Makes sense, I suppose. > You would need to change_page_attr() every kernel address that is mapped into > the IOMMU to use an uncached aperture. AGP does this, but the frequency of > mapping for the IOMMU is much higher and it would be prohibitively costly > unfortunately. But it still might be a reasonable thing to do to test the theory that the problem is cache coherency across the graphics aperture, even if it isn't a long-term solution for the problem. > In the past we saw corruptions from such conflicts, so this is more > than just theory. I suspect you traded a more easy to trigger > corruption with a more subtle one. Yup. That was the inspiration for the script. Chip -- Charles M. "Chip" Coldwell Senior Software Engineer Red Hat, Inc 978-392-2426 - 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/