Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755216AbaFWJPr (ORCPT ); Mon, 23 Jun 2014 05:15:47 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:56207 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753875AbaFWJMY (ORCPT ); Mon, 23 Jun 2014 05:12:24 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@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 , Jiri Slaby Subject: [PATCH 3.12 035/111] sched: Fix hotplug vs. set_cpus_allowed_ptr() Date: Mon, 23 Jun 2014 10:31:10 +0200 Message-Id: <774f680a78bd9ac6ccac097e7826632e506046a9.1403512281.git.jslaby@suse.cz> X-Mailer: git-send-email 2.0.0 In-Reply-To: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> References: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- kernel/cpu.c | 6 ++++-- kernel/sched/core.c | 1 - 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index d7f07a2da5a6..92599d897125 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -695,10 +695,12 @@ void set_cpu_present(unsigned int cpu, bool present) 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) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a494ace683e3..07039cba59d9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4726,7 +4726,6 @@ static int sched_cpu_active(struct notifier_block *nfb, 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; -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/