From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754851AbZHYK2Q (ORCPT ); Tue, 25 Aug 2009 06:28:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752990AbZHYK2Q (ORCPT ); Tue, 25 Aug 2009 06:28:16 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:45758 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752725AbZHYK2P (ORCPT ); Tue, 25 Aug 2009 06:28:15 -0400 Date: Tue, 25 Aug 2009 12:28:06 +0200 From: Ingo Molnar To: Andreas Herrmann Cc: Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [PATCH 15/15] x86: Fix cpu_coregroup_mask to return correct cpumask on multi-node processors Message-ID: <20090825102806.GA19941@elte.hu> References: <20090820131243.GO29327@alberich.amd.com> <20090820134604.GD29327@alberich.amd.com> <1251128176.7538.301.camel@twins> <20090825093101.GJ20811@alberich.amd.com> <1251194143.7538.1128.camel@twins> <20090825102409.GK20811@alberich.amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090825102409.GK20811@alberich.amd.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andreas Herrmann wrote: > On Tue, Aug 25, 2009 at 11:55:43AM +0200, Peter Zijlstra wrote: > > On Tue, 2009-08-25 at 11:31 +0200, Andreas Herrmann wrote: > > > On Mon, Aug 24, 2009 at 05:36:16PM +0200, Peter Zijlstra wrote: > > > > On Thu, 2009-08-20 at 15:46 +0200, Andreas Herrmann wrote: > > > > > The correct mask that describes core-siblings of an processor > > > > > is topology_core_cpumask. See topology adapation patches, especially > > > > > http://marc.info/?l=linux-kernel&m=124964999608179 > > > > > > > > > > > > argh, violence, murder kill.. this is the worst possible hack and you're > > > > extending it :/ > > > > > > So this is the third code area > > > (besides sched_*_power_savings sysfs interface, and the __cpu_power fiddling) > > > that is crap, mess, a hack. > > > > > > Didn't know that I'd enter such a minefield when touching this code. ;-( > > > > Yeah, you're lucky that way ;-) Its been creaking for a while, and I've > > been making noises to the IBM people (who so far have been the main > > source of power saving patches) to clean this up, but now you trod onto > > all of it at once.. > > > > > What would be your perferred solution for the > > > core_cpumask/llc_shared_map stuff? Another domain level to get rid of > > > this function? > > > > Right, I'd like to see everything exposed as domain levels. > > > > > > numa-cluster > > numa > > socket > > in-socket-numa > > multi-core > > shared-cache > > core > > threads > > > > We currently have a fixed order of these things, but I think we should > > simply provide helpers for building the sd tree and let the arch code do > > that instead of exporting all these masks in a fixed order. > > > > Once we get the arch domain tree, we do degenerate stuff to cull all the > > trivial domains and fold SD flags. > > So any in-socket-numa is only going to haeppen with the > arch-defined domain tree. > > Now that this is settled you should throw away the > __build_sched_domains cleanup patches that are in tip. They won't > be of use when domain creation code is basically changed. I'd rather keep them - it gives a better/cleaner basis to develop the new stuff. Ingo