From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753083Ab0IVXRB (ORCPT ); Wed, 22 Sep 2010 19:17:01 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33617 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752134Ab0IVXRA (ORCPT ); Wed, 22 Sep 2010 19:17:00 -0400 Message-ID: <4C9A8E4C.9030504@zytor.com> Date: Wed, 22 Sep 2010 16:16:28 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100907 Fedora/3.1.3-1.fc13 Thunderbird/3.1.3 MIME-Version: 1.0 To: David Rientjes CC: Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Yinghai Lu , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: tidy e820 output References: <20100922172744.19085.41844.stgit@bob.kio> <201009221220.34066.bjorn.helgaas@hp.com> <4C9A4AAF.3030503@zytor.com> <201009221253.01049.bjorn.helgaas@hp.com> <4C9A51DC.5020009@zytor.com> <4C9A881B.9010309@zytor.com> In-Reply-To: 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 09/22/2010 04:12 PM, David Rientjes wrote: > On Wed, 22 Sep 2010, H. Peter Anvin wrote: > >>> This patch is going to break our userspace parsing scripts if you change >>> the output format. Admittedly, we're probably one of the few users who >>> actually parses this output, but we do have reasons to do it for our >>> firmware. If there was some improvement being introduced here, we'd >>> happily handle multiple regexs (we constantly add new patterns when new >>> kernels are released), but I'm not seeing how this is better. >> >> Kernel messages are not an ABI or API. >> >> The user space API for this stuff is /sys/firmware/memmap. >> > > I'm referring to using [start, start + addr - 1] in the output, like > /sys/firmware/memmap does, as opposed to [start, start + addr]. Is it not > valuable to include the actual e820 map in some way, especially when you > have your own BIOS? We've always used this output since it isn't > available later. "The actual e820 map" contains (start, length, type) -- the end bracket is not part of it at all. Either way, /sys/firmware/memmap does provide the memory map as provided by the firmware through whatever means. > Another use of this information that people may already be using it for is > ensuring the memmap= on the command line is parsed correctly. > > So, again, I'm looking for the benefit here in this patch and it's not > immediately apparent to me. Consistency with other resources displayed seems like a major win to me. -hpa