From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754247Ab3GAQEs (ORCPT ); Mon, 1 Jul 2013 12:04:48 -0400 Received: from multi.imgtec.com ([194.200.65.239]:10418 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752123Ab3GAQEq (ORCPT ); Mon, 1 Jul 2013 12:04:46 -0400 From: James Hogan To: CC: Thomas Gleixner , James Hogan , "Srivatsa S. Bhat" , Oleg Nesterov , "Anton Vorontsov" Subject: [PATCH 1/5] metag: use clear_tasks_mm_cpumask() Date: Mon, 1 Jul 2013 17:04:15 +0100 Message-ID: <1372694659-30176-2-git-send-email-james.hogan@imgtec.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1372694659-30176-1-git-send-email-james.hogan@imgtec.com> References: <1372694659-30176-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-SEF-Processed: 7_3_0_01192__2013_07_01_17_04_44 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() was introduced in v3.5-rc1 to fix this issue, so let's use it for metag too. Signed-off-by: James Hogan Cc: "Srivatsa S. Bhat" Cc: Thomas Gleixner Cc: Oleg Nesterov Cc: Anton Vorontsov --- arch/metag/kernel/smp.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c index 86fdda4..b813515 100644 --- a/arch/metag/kernel/smp.c +++ b/arch/metag/kernel/smp.c @@ -276,7 +276,6 @@ static DECLARE_COMPLETION(cpu_killed); int __cpuexit __cpu_disable(void) { unsigned int cpu = smp_processor_id(); - struct task_struct *p; /* * Take this CPU offline. Once we clear this, we can't return, @@ -296,12 +295,7 @@ int __cpuexit __cpu_disable(void) flush_cache_all(); local_flush_tlb_all(); - read_lock(&tasklist_lock); - for_each_process(p) { - if (p->mm) - cpumask_clear_cpu(cpu, mm_cpumask(p->mm)); - } - read_unlock(&tasklist_lock); + clear_tasks_mm_cpumask(cpu); return 0; } -- 1.8.1.2