From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756102AbYFPPtt (ORCPT ); Mon, 16 Jun 2008 11:49:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753971AbYFPPtm (ORCPT ); Mon, 16 Jun 2008 11:49:42 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45153 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753609AbYFPPtl (ORCPT ); Mon, 16 Jun 2008 11:49:41 -0400 Message-ID: <48568B56.7060307@zytor.com> Date: Mon, 16 Jun 2008 08:48:38 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: "Huang, Ying" CC: Paul Jackson , mingo@elte.hu, tglx@linutronix.de, yhlu.kernel@gmail.com, steiner@sgi.com, travis@sgi.com, linux-kernel@vger.kernel.org, andi@firstfloor.org, akpm@linux-foundation.org Subject: Re: [PATCH 4/8] x86 boot: allow overlapping ebda and efi memmap memory ranges References: <20080616062945.14597.78009.sendpatchset@polaris-admin.engr.sgi.com> <20080616063001.14597.96170.sendpatchset@polaris-admin.engr.sgi.com> <1213600062.11185.13.camel@caritas-dev.intel.com> <20080616032457.718f4d87.pj@sgi.com> <1213606435.12968.14.camel@caritas-dev.intel.com> In-Reply-To: <1213606435.12968.14.camel@caritas-dev.intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Huang, Ying wrote: >>> Or do not reserve EBDA on EFI system. >> I suppose. This would have been a bigger change than I could >> suggest. For all I know, there are existing systems using EBDA >> and EFI together. Would this change break them? >> >> If you have good reason to know that's essentially impossible then >> I have no objections, so far as my needs go, to not reserving EBDA >> on EFI systems. > > I think if EBDA area is used in EFI system, it should be reserved in EFI > memory map. Realistically, we need the infrastructure to be able to make paranoia reservations, and you need to be able to deal with later finding they are actually in use. That's part of why we *make* paranoia reservations. It's not acceptable to say "oh, it's EFI, we don't need it" -- that's equivalent to saying "oh, EFI firmware won't have any bugs." Although I know there are plenty of EFI fanboys who seem to have that idea, I consider it about as likely as the tooth fairy. -hpa