From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755392AbaEVM1U (ORCPT ); Thu, 22 May 2014 08:27:20 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51210 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755356AbaEVM1P (ORCPT ); Thu, 22 May 2014 08:27:15 -0400 Date: Thu, 22 May 2014 05:26:02 -0700 From: tip-bot for Lai Jiangshan Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, srivatsa.bhat@linux.vnet.ibm.com, rafael.j.wysocki@intel.com, toshi.kani@hp.com, ego@linux.vnet.ibm.com, akpm@linux-foundation.org, wangyun@linux.vnet.ibm.com, tglx@linutronix.de, laijs@cn.fujitsu.com, paul.gortmaker@windriver.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, rafael.j.wysocki@intel.com, srivatsa.bhat@linux.vnet.ibm.com, toshi.kani@hp.com, ego@linux.vnet.ibm.com, akpm@linux-foundation.org, wangyun@linux.vnet.ibm.com, tglx@linutronix.de, laijs@cn.fujitsu.com, paul.gortmaker@windriver.com In-Reply-To: <53758B12.8060609@cn.fujitsu.com> References: <53758B12.8060609@cn.fujitsu.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched: Fix hotplug vs. set_cpus_allowed_ptr() Git-Commit-ID: 6acbfb96976fc3350e30d964acb1dbbdf876d55e X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 6acbfb96976fc3350e30d964acb1dbbdf876d55e Gitweb: http://git.kernel.org/tip/6acbfb96976fc3350e30d964acb1dbbdf876d55e Author: Lai Jiangshan AuthorDate: Fri, 16 May 2014 11:50:42 +0800 Committer: Ingo Molnar CommitDate: Thu, 22 May 2014 10:21:31 +0200 sched: Fix hotplug vs. set_cpus_allowed_ptr() 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 --- 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 a9e710e..247979a 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -726,10 +726,12 @@ 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 44e00ab..86f3890 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5076,7 +5076,6 @@ 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;