From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754529AbZHYJOn (ORCPT ); Tue, 25 Aug 2009 05:14:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753181AbZHYJOl (ORCPT ); Tue, 25 Aug 2009 05:14:41 -0400 Received: from sg2ehsobe003.messaging.microsoft.com ([207.46.51.77]:52982 "EHLO SG2EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751308AbZHYJOl convert rfc822-to-8bit (ORCPT ); Tue, 25 Aug 2009 05:14:41 -0400 X-SpamScore: -17 X-BigFish: VPS-17(zz1432R98dN936eMa594izz1202hzzz32i6bh203h43j61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0KOXDO4-01-46O-02 X-M-MSG: Date: Tue, 25 Aug 2009 11:13:53 +0200 From: Andreas Herrmann To: Peter Zijlstra CC: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH 13/15] sched: Detect child domain of NUMA (aka NODE) domain Message-ID: <20090825091353.GH20811@alberich.amd.com> References: <20090820131243.GO29327@alberich.amd.com> <20090820134347.GB29327@alberich.amd.com> <1251128058.7538.299.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: <1251128058.7538.299.camel@twins> User-Agent: Mutt/1.5.16 (2007-06-09) X-OriginalArrivalTime: 25 Aug 2009 09:13:53.0711 (UTC) FILETIME=[5DFA1BF0:01CA2564] Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 24, 2009 at 05:34:18PM +0200, Peter Zijlstra wrote: > On Thu, 2009-08-20 at 15:43 +0200, Andreas Herrmann wrote: > > On multi-node processors a NUMA node might not span a socket. > > Instead a socket might span several NUMA nodes. > > > > This patch introduces a check whether NODE domain is parent > > of MC domain and sets s_data.numa_child_level accordingly. > > (See previous patch for further details.) > > right, except that the previous patch > was rather cryptic :/ Sorry for that. > So you're proposing to have the NODE level depend on multi-node and then > flip NODE and CPU around? Conditioned. Only if a NUMA node does not span an entire socket, e.g. node 0: 0-3 node 1: 4-7 socket 0: 0-3, 4-7 You may have a SRAT that describes one NUMA node containing all sockets, e.g. node 0: 0-7 socket 0 : 0-7 If we have something like that on a multi-node processor system then we don't need to flip NODE and CPU around. Same is true if there is no SRAT or SRAT is bogus or CONFIG_ACPI_NUMA=n. In theory, I could also think of node interleaving where a NUMA node spans internal nodes of a socket on a multi-node processor -- no flip in domain hierarchy needed. On balance, as soon as a socket spans more than one NUMA node we have to flip NODE and CPU. Regards, Andreas -- Operating | Advanced Micro Devices GmbH System | Karl-Hammerschmidt-Str. 34, 85609 Dornach b. München, Germany Research | Geschäftsführer: Thomas M. McCoy, Giuliano Meroni Center | Sitz: Dornach, Gemeinde Aschheim, Landkreis München (OSRC) | Registergericht München, HRB Nr. 43632