From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758874AbYEBFFj (ORCPT ); Fri, 2 May 2008 01:05:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751062AbYEBFFb (ORCPT ); Fri, 2 May 2008 01:05:31 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46549 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750984AbYEBFFb (ORCPT ); Fri, 2 May 2008 01:05:31 -0400 Message-ID: <481AA042.7060101@zytor.com> Date: Thu, 01 May 2008 22:01:54 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Robert Hancock CC: Andi Kleen , Jesse Barnes , linux-pci@atrey.karlin.mff.cuni.cz, TJ , Ingo Molnar , Thomas Gleixner , linux-kernel Subject: Re: Why such a big difference in init-time PCI resource call-paths (x86 vs x86_64) ? References: <481AA095.3010201@shaw.ca> In-Reply-To: <481AA095.3010201@shaw.ca> 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 Robert Hancock wrote: >> >> Yes, considering all possible reservation schemes is really critical >> here (including the magic knowledge of the legacy region). > > FYI, from what I've read, Windows ignores e820 for detecting resource > reservations and looks at ACPI reservations only (at least if it's > running in ACPI mode which these days is almost universal). It seems > Windows really only uses e820 for locating RAM areas.. There is no doubt ACPI is critical. Using E820 is good practice too, though. Windows actually uses (only) one of several methods, depending on which HAL it chooses to use. -hpa