From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757258AbaIRAdP (ORCPT ); Wed, 17 Sep 2014 20:33:15 -0400 Received: from www.sr71.net ([198.145.64.142]:37628 "EHLO blackbird.sr71.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755768AbaIRAdO (ORCPT ); Wed, 17 Sep 2014 20:33:14 -0400 Message-ID: <541A2848.6030308@sr71.net> Date: Wed, 17 Sep 2014 17:33:12 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Peter Zijlstra CC: linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@linux.intel.com, ak@linux.intel.com, Alex Chiang , Borislav Petkov , Rusty Russell , Mike Travis , Greg Kroah-Hartman , Heiko Carstens Subject: Re: [PATCH] x86: Consider multiple nodes in a single socket to be "sane" References: <20140915222641.D640BD8A@viggo.jf.intel.com> <20140916032920.GH2840@worktop.localdomain> <5417F228.9060301@sr71.net> <20140916175851.GC2848@worktop.localdomain> <5418CC6F.2040803@sr71.net> <20140917225726.GH2848@worktop.localdomain> In-Reply-To: <20140917225726.GH2848@worktop.localdomain> 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 09/17/2014 03:57 PM, Peter Zijlstra wrote: >> > Another option would be to: >> > 1. Add a new "PKG" level and actually _build_ it with phys_proc_id >> > 2. Make sure to tie the sysfs 'core_siblings' file to PKG >> > 3. Leave the "MC" level as it is now, but define it as being the lowest- >> > common-denominator of core grouping. In other words, the "MC" group >> > will stop at a NUMA node or a socket boundary, whichever it sees >> > first. >> > 4. Chop the "COD_NUMA" level off in sched_init_numa() > No, we should provide an arch override for sched_domain_topology which > has the right setup for the detected topology. > > See arm,powerpc and s390, which already have his. I _think_ the problem here is that all of the existing topologies describe something below the smallest NUMA node. With the cluster-on-die stuff, we've got a node boundary smack in the middle of the existing topology levels. So, if we're going to do this with a new sched_domain_topology, we've got to make sure that we eliminate all of the levels below that first NUMA node. I think that means just have a topology with the SMT level alone in it. Does that work?