Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760025AbXI0Wdi (ORCPT ); Thu, 27 Sep 2007 18:33:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759023AbXI0Wda (ORCPT ); Thu, 27 Sep 2007 18:33:30 -0400 Received: from outbound-fra.frontbridge.com ([62.209.45.174]:43066 "EHLO outbound1-fra-R.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758762AbXI0Wd3 (ORCPT ); Thu, 27 Sep 2007 18:33:29 -0400 X-BigFish: VP X-MS-Exchange-Organization-Antispam-Report: OrigIP: 163.181.251.8;Service: EHS X-Server-Uuid: D6C75999-9DAF-4D89-B9AC-C25E3A0BB76A Date: Thu, 27 Sep 2007 16:33:36 -0600 From: "Jordan Crouse" To: "H. Peter Anvin" cc: jkeating@redhat.com, "Joerg Pommnitz" , "Chuck Ebbert" , "Linux Kernel Mailing List" , "Andi Kleen" Subject: Re: More E820 brokenness Message-ID: <20070927223336.GB4755@cosmic.amd.com> References: <46FC2BFD.6070200@zytor.com> MIME-Version: 1.0 In-Reply-To: <46FC2BFD.6070200@zytor.com> User-Agent: Mutt/1.5.13 (2006-08-11) X-OriginalArrivalTime: 27 Sep 2007 22:33:07.0420 (UTC) FILETIME=[6047E9C0:01C80156] X-WSS-ID: 6AE2F0292ZC500270-01-01 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1454 Lines: 35 On 27/09/07 15:17 -0700, H. Peter Anvin wrote: > As luck would have it, it's not just an obscure Geode system which has a > broken E820 implementation. Today I received a bug report about a Dell > system (XPS M1330) with broken E820. > > Unfortunately, the workaround for the Geode breaks this system, because > x86-64 doesn't fall back to the e801/88 information like the i386 kernel > does. > > I wonder if the relevant people could test out this patch to see how it > works on their respective system. This patch reverts to 2.6.23-rc8 > behaviour of simply truncating the map, but still makes e801/88 info > available to the kernel; this hopefully should match 2.6.22 behaviour. Breaks on the Geode - original behavior. I think that having boot_prams.e820_entries != 0 makes the kernel assume the e820 data is correct. > I want to emphasize that this is seriously broken. Using a partial e820 > map could have disastrous results, since the kernel will have partial > memory map information and not know about reserved areas, etc. Part of > me feels that the right thing to do is what the current git kernel does > -- either fall back to e801, or stop and error. I'm inclined to agree. Jordan - 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/