From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755400Ab3E0RJU (ORCPT ); Mon, 27 May 2013 13:09:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50828 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752566Ab3E0RJT (ORCPT ); Mon, 27 May 2013 13:09:19 -0400 From: Andrew Jones To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, a.p.zijlstra@chello.nl, fenghua.yu@intel.com Cc: linux-kernel@vger.kernel.org Subject: [PATCH] sched/x86: construct all sibling maps if smt Date: Mon, 27 May 2013 19:09:00 +0200 Message-Id: <1369674540-10601-1-git-send-email-drjones@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 316ad248307fb ("sched/x86: Rewrite set_cpu_sibling_map()") broke the construction of sibling maps, which also broke the booted_cores accounting. Before the rewrite, if smt was present, then each map was updated for each smt sibling. After the rewrite only cpu_sibling_mask gets updated, as the llc and core maps depend on 'has_mc = x86_max_cores > 1' instead. This leads to problems with topologies like the following (qemu -smp sockets=2,cores=1,threads=2) processor : 0 physical id : 0 siblings : 1 <= should be 2 core id : 0 cpu cores : 1 processor : 1 physical id : 0 siblings : 1 <= should be 2 core id : 0 cpu cores : 0 <= should be 1 processor : 2 physical id : 1 siblings : 1 <= should be 2 core id : 0 cpu cores : 1 processor : 3 physical id : 1 siblings : 1 <= should be 2 core id : 0 cpu cores : 0 <= should be 1 This patch restores the former construction by defining has_mc as (has_smt || x86_max_cores > 1). This should be fine as there were no (has_smt && !has_mc) conditions in the context. Signed-off-by: Andrew Jones --- arch/x86/kernel/smpboot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 9c73b51817e47..886a3234eaff3 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -372,15 +372,15 @@ static bool __cpuinit match_mc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) void __cpuinit set_cpu_sibling_map(int cpu) { - bool has_mc = boot_cpu_data.x86_max_cores > 1; bool has_smt = smp_num_siblings > 1; + bool has_mc = has_smt || boot_cpu_data.x86_max_cores > 1; struct cpuinfo_x86 *c = &cpu_data(cpu); struct cpuinfo_x86 *o; int i; cpumask_set_cpu(cpu, cpu_sibling_setup_mask); - if (!has_smt && !has_mc) { + if (!has_mc) { cpumask_set_cpu(cpu, cpu_sibling_mask(cpu)); cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu)); cpumask_set_cpu(cpu, cpu_core_mask(cpu)); -- 1.8.1.4