From patchwork Thu Jan 23 20:39:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 213266 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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 28398C2D0DB for ; Thu, 23 Jan 2020 20:40:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9F60246B3 for ; Thu, 23 Jan 2020 20:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729406AbgAWUjt (ORCPT ); Thu, 23 Jan 2020 15:39:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:45974 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729355AbgAWUjs (ORCPT ); Thu, 23 Jan 2020 15:39:48 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5E74724695; Thu, 23 Jan 2020 20:39:47 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1iujGU-000mh5-AE; Thu, 23 Jan 2020 15:39:46 -0500 Message-Id: <20200123203946.200669575@goodmis.org> User-Agent: quilt/0.65 Date: Thu, 23 Jan 2020 15:39:57 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Julia Cartwright , Daniel Wagner , Tom Zanussi , Dick Hollenbeck Subject: [PATCH RT 27/30] sched/core: migrate_enable() must access takedown_cpu_task on !HOTPLUG_CPU References: <20200123203930.646725253@goodmis.org> MIME-Version: 1.0 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org 4.19.94-rt39-rc2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior [ Upstream commit a61d1977f692e46bad99a100f264981ba08cb4bd ] The variable takedown_cpu_task is never declared/used on !HOTPLUG_CPU except for migrate_enable(). This leads to a link error. Don't use takedown_cpu_task in !HOTPLUG_CPU. Reported-by: Dick Hollenbeck Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/cpu.c | 2 ++ kernel/sched/core.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/kernel/cpu.c b/kernel/cpu.c index 5366c8c69c2f..b9d7ac61d707 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -846,7 +846,9 @@ static int take_cpu_down(void *_param) return 0; } +#ifdef CONFIG_PREEMPT_RT_BASE struct task_struct *takedown_cpu_task; +#endif static int takedown_cpu(unsigned int cpu) { diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e465381b464d..cbd76324babd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7314,9 +7314,11 @@ void migrate_enable(void) p->migrate_disable = 0; rq->nr_pinned--; +#ifdef CONFIG_HOTPLUG_CPU if (rq->nr_pinned == 0 && unlikely(!cpu_active(cpu)) && takedown_cpu_task) wake_up_process(takedown_cpu_task); +#endif if (!p->migrate_disable_scheduled) goto out;