From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758895Ab1DNOch (ORCPT ); Thu, 14 Apr 2011 10:32:37 -0400 Received: from terminus.zytor.com ([198.137.202.10]:47022 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758837Ab1DNOcg (ORCPT ); Thu, 14 Apr 2011 10:32:36 -0400 Message-ID: <4DA7054B.1060203@zytor.com> Date: Thu, 14 Apr 2011 07:31:39 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110403 Fedora/3.1.9-6.fc15 Thunderbird/3.1.9 MIME-Version: 1.0 To: Ingo Molnar CC: Joerg Roedel , Yinghai Lu , Alex Deucher , Linus Torvalds , Linux Kernel Mailing List , dri-devel@lists.freedesktop.org, Thomas Gleixner , Tejun Heo Subject: Re: Linux 2.6.39-rc3 References: <20110412090207.GE19819@8bytes.org> <20110412184433.GF19819@8bytes.org> <20110413064609.GA18777@elte.hu> <20110413172147.GI19819@8bytes.org> <4DA5F62F.3030504@kernel.org> <4DA654D6.2060103@zytor.com> <20110414085624.GC18463@8bytes.org> <20110414091137.GC9248@elte.hu> In-Reply-To: <20110414091137.GC9248@elte.hu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/14/2011 02:11 AM, Ingo Molnar wrote: > > I'd strongly suggest we revert back to the old and proven allocation order, as > long as it results in valid layouts. Even if we figure out this particular > GART/GTT assumption there might be a dozen others in other types of hardware. > Yes, but we might also be hiding a real bug which bites other hardware. We have found real and very serious bugs in the kernel this way before -- things where drivers scribble over random memory and allocation order exposed the failure in a predictable way, as opposed to random crashes. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.