From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751889AbWFVTVx (ORCPT ); Thu, 22 Jun 2006 15:21:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751891AbWFVTVx (ORCPT ); Thu, 22 Jun 2006 15:21:53 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:42632 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751889AbWFVTVw (ORCPT ); Thu, 22 Jun 2006 15:21:52 -0400 Subject: Re: [RFC] patch [1/1] convert i386 summit subarch to use SRAT data for apicid_to_node From: keith mannthey Reply-To: kmannth@us.ibm.com To: "Martin J. Bligh" Cc: Dave Jones , lkml In-Reply-To: <449A3A70.5000906@mbligh.org> References: <1150941296.10001.25.camel@keithlap> <20060622022414.GB4449@redhat.com> <1150948551.10001.62.camel@keithlap> <449A3A70.5000906@mbligh.org> Content-Type: text/plain Organization: Linux Technology Center IBM Date: Thu, 22 Jun 2006 12:21:49 -0700 Message-Id: <1151004109.5880.29.camel@keithlap> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-06-21 at 23:36 -0700, Martin J. Bligh wrote: > keith mannthey wrote: > > On Wed, 2006-06-21 at 22:24 -0400, Dave Jones wrote: > > > >>On Wed, Jun 21, 2006 at 06:54:55PM -0700, keith mannthey wrote: > >> > Hello All, > >> > This patch converts the i386 summit subarch apicid_to_node to use node > >> > information provided by the SRAT. The current way of obtaining the > >> > nodeid > >> > > >> > static inline int apicid_to_node(int logical_apicid) > >> > { > >> > return logical_apicid >> 5; > >> > } > >> > > >> > is just not correct for all summit systems/bios. Assuming the apicid > >> > matches the Linux node number require a leap of faith that the bios lay- > >> > ed out the apicids a set way. Modern summit HW does not layout its bios > >> > in the manner for various reasons and is unable to boot i386 numa. > >> > > >> > The best way to get the correct apicid to node information is from the > >> > SRAT table. > >> > >>Do all summit's have SRAT tables ? > >>I was under the impression the early ones were around before > >>the invention of SRAT. > > > > > > That is a good point. Let me check into the x440 (1st gen). x445 x460 > > (2nd,3rd gen) uses SRAT for sure (these patches have been tested on > > these systems). > > > > The x440 lists an srat but maybe it is using some special bios area. I > > will build a test kernel give it a whirl. > > I'm pretty sure they all had SRAT tables - the test machine we use > regularly for test.kernel.org (elm3b67) does. The NUMA-Q (x430) doesn't, > but that's a separate subarch. Tested ontop of x440 just fine it does use the SRAT. It doesn't do anything NUMA-Q like :) Thanks, keith mannthey Linux Technology Center IBM