From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934495AbaFIW6I (ORCPT ); Mon, 9 Jun 2014 18:58:08 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57087 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933755AbaFIWp7 (ORCPT ); Mon, 9 Jun 2014 18:45:59 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lai Jiangshan , Peter Zijlstra , Andrew Morton , "Gautham R. Shenoy" , Linus Torvalds , Michael wang , Paul Gortmaker , "Rafael J. Wysocki" , "Srivatsa S. Bhat" , Toshi Kani , Ingo Molnar Subject: [PATCH 3.10 19/40] sched: Fix hotplug vs. set_cpus_allowed_ptr() Date: Mon, 9 Jun 2014 15:48:50 -0700 Message-Id: <20140609224839.814100625@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140609224839.127615063@linuxfoundation.org> References: <20140609224839.127615063@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lai Jiangshan commit 6acbfb96976fc3350e30d964acb1dbbdf876d55e upstream. Lai found that: WARNING: CPU: 1 PID: 13 at arch/x86/kernel/smp.c:124 native_smp_send_reschedule+0x2d/0x4b() ... migration_cpu_stop+0x1d/0x22 was caused by set_cpus_allowed_ptr() assuming that cpu_active_mask is always a sub-set of cpu_online_mask. This isn't true since 5fbd036b552f ("sched: Cleanup cpu_active madness"). So set active and online at the same time to avoid this particular problem. Fixes: 5fbd036b552f ("sched: Cleanup cpu_active madness") Signed-off-by: Lai Jiangshan Signed-off-by: Peter Zijlstra Cc: Andrew Morton Cc: Gautham R. Shenoy Cc: Linus Torvalds Cc: Michael wang Cc: Paul Gortmaker Cc: Rafael J. Wysocki Cc: Srivatsa S. Bhat Cc: Toshi Kani Link: http://lkml.kernel.org/r/53758B12.8060609@cn.fujitsu.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/cpu.c | 6 ++++-- kernel/sched/core.c | 1 - 2 files changed, 4 insertions(+), 3 deletions(-) --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -698,10 +698,12 @@ void set_cpu_present(unsigned int cpu, b void set_cpu_online(unsigned int cpu, bool online) { - if (online) + if (online) { cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); - else + cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); + } else { cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); + } } void set_cpu_active(unsigned int cpu, bool active) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5270,7 +5270,6 @@ static int __cpuinit sched_cpu_active(st unsigned long action, void *hcpu) { switch (action & ~CPU_TASKS_FROZEN) { - case CPU_STARTING: case CPU_DOWN_FAILED: set_cpu_active((long)hcpu, true); return NOTIFY_OK;