Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753318Ab2JCSJM (ORCPT ); Wed, 3 Oct 2012 14:09:12 -0400 Received: from mail.x86-64.org ([217.9.48.20]:34169 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750748Ab2JCSJK (ORCPT ); Wed, 3 Oct 2012 14:09:10 -0400 Date: Wed, 3 Oct 2012 20:08:59 +0200 From: Borislav Petkov To: "H. Peter Anvin" Cc: Daniel Blueman , Ingo Molnar , Steffen Persvold , Thomas Gleixner , linux-kernel@vger.kernel.org, Borislav Petkov , x86@kernel.org Subject: Re: [PATCH] RFC: Fix AMD Northbridge-ID contiguity assumptions Message-ID: <20121003180859.GB15939@aftab.osrc.amd.com> References: <1349256029-14851-1-git-send-email-daniel@numascale-asia.com> <506C56B2.50505@zytor.com> <506C5EDB.9000107@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <506C5EDB.9000107@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1951 Lines: 54 On Wed, Oct 03, 2012 at 08:50:51AM -0700, H. Peter Anvin wrote: > On 10/03/2012 08:30 AM, Daniel Blueman wrote: > > > > > > Is that "on NumaScale systems"? If so, please say so rather than trying > > > to make it sound generic; if it is not, can you give some other examples? > > > >It is for Numascale (NumaChip) systems for our purposes. > > > >Any other systems which interconnect Opterons via address space routing > >(needed for >8 HT nodes) will get this benefit. I can't put my hand to > >exactly what is out there, but can find out. > > > > The reason I'm asking is because it is an important bit of the > record of the code to know if this is a specific need or a general > need. This may be obvious now, but 5-10 years from now someone will > need to know why or what. > > The two paragraphs above is exactly what is needed, i.e. "NumaChip > or any other design which shares these specific design features: > ..." Absolutely! And it would be best to put that explanation in the code somewhere around node_to_amd_index() so that it is there at a first glance. Btw, I'll review the patch tomorrow since it is a holiday today here. I have only two nits for now: * node is u32, do you really have such big systems with 2^32-1 nodes? Or can the max node number fit into a, say, u16 or u8? * node_to_amd_index returns 0 in the unsuccessful case but node index 0 seems ok to me, i.e. the first element in the array of northbridges. It probably should return a negative value rather to signal a failure... Thanks. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551 -- 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/