From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25E95C4BA1B for ; Wed, 26 Feb 2020 16:42:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05D5024670 for ; Wed, 26 Feb 2020 16:42:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727860AbgBZQma (ORCPT ); Wed, 26 Feb 2020 11:42:30 -0500 Received: from foss.arm.com ([217.140.110.172]:38934 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726151AbgBZQm1 (ORCPT ); Wed, 26 Feb 2020 11:42:27 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5332031B; Wed, 26 Feb 2020 08:42:27 -0800 (PST) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BA2343F819; Wed, 26 Feb 2020 08:42:25 -0800 (PST) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Peter Zijlstra , Ingo Molnar , Vincent Guittot , Dietmar Eggemann , morten.rasmussen@arm.com, qperret@google.com, Catalin Marinas , Will Deacon , Mark Rutland Subject: [PATCH 1/2] sched/topology: Don't enable EAS on SMT systems Date: Wed, 26 Feb 2020 16:41:17 +0000 Message-Id: <20200226164118.6405-2-valentin.schneider@arm.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200226164118.6405-1-valentin.schneider@arm.com> References: <20200226164118.6405-1-valentin.schneider@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org EAS already requires asymmetric CPU capacities to be enabled, and mixing this with SMT is an aberration, but better be safe than sorry. Signed-off-by: Valentin Schneider --- kernel/sched/topology.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 00911884b7e7..76cd0a370b9a 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -360,6 +360,10 @@ static bool build_perf_domains(const struct cpumask *cpu_map) goto free; } + /* EAS definitely does *not* handle SMT */ + if (sched_smt_active()) + goto free; + for_each_cpu(i, cpu_map) { /* Skip already covered CPUs. */ if (find_pd(pd, i)) -- 2.24.0