From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752828AbdDNQtX (ORCPT ); Fri, 14 Apr 2017 12:49:23 -0400 Received: from merlin.infradead.org ([205.233.59.134]:43562 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbdDNQtV (ORCPT ); Fri, 14 Apr 2017 12:49:21 -0400 Date: Fri, 14 Apr 2017 18:49:09 +0200 From: Peter Zijlstra To: Lauro Ramos Venancio Cc: linux-kernel@vger.kernel.org, lwang@redhat.com, riel@redhat.com, Mike Galbraith , Thomas Gleixner , Ingo Molnar Subject: Re: [RFC 3/3] sched/topology: Different sched groups must not have the same balance cpu Message-ID: <20170414164909.tfybszncwkm4yxap@hirez.programming.kicks-ass.net> References: <1492091769-19879-1-git-send-email-lvenanci@redhat.com> <1492091769-19879-4-git-send-email-lvenanci@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1492091769-19879-4-git-send-email-lvenanci@redhat.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 13, 2017 at 10:56:09AM -0300, Lauro Ramos Venancio wrote: > Currently, the group balance cpu is the groups's first CPU. But with > overlapping groups, two different groups can have the same first CPU. > > This patch uses the group mask to mark all the CPUs that have a > particular group as its main sched group. The group balance cpu is the > first group CPU that is also in the mask. Please give a NUMA configuration and CPU number where this goes wrong. Because only the first group of a domain matters, and with the other thing fixed, I'm not immediately seeing where we go wobbly.