From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754307Ab3A2BKe (ORCPT ); Mon, 28 Jan 2013 20:10:34 -0500 Received: from terminus.zytor.com ([198.137.202.10]:48099 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751342Ab3A2BKd (ORCPT ); Mon, 28 Jan 2013 20:10:33 -0500 Message-ID: <51072147.9090306@zytor.com> Date: Mon, 28 Jan 2013 17:09:27 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Thomas Renninger CC: yinghai@kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, vgoyal@redhat.com, horms@verge.net.au Subject: Re: [PATCH 1/2] x86 e820: Check for exactmap appearance when parsing first memmap option References: <1358868049-19884-1-git-send-email-trenn@suse.de> <1358868049-19884-2-git-send-email-trenn@suse.de> In-Reply-To: <1358868049-19884-2-git-send-email-trenn@suse.de> X-Enigmail-Version: 1.5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/22/2013 07:20 AM, Thomas Renninger wrote: > From: Yinghai Lu > > memmap=exactmap will throw away all original, but also until then > user defined (through other provided memmap= parameters) areas. > That means all memmap= boot parameters passed before a memmap=exactmap > parameter are not recognized. > Without this fix: > memmap=x@y memmap=exactmap memmap=i#k > only i#k would get recognized. > > This is wrong, this fix will only throw away all original e820 areas once > when memmap=exactmap is found in the whole boot command line and before > any other memmap= option is parsed. > I don't understand why this is wrong. The kernel command line is always parsed from left to right, and I don't see anything inherently problematic with that with something like a big hammer like exactmap. -hpa