From 3eaa73bde2fb475b731a0fde7dd11c3ecfb8679c Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Thu, 31 May 2012 16:26:22 -0700 Subject: [PATCH] arm: use clear_tasks_mm_cpumask() 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() has this issue fixed, so let's use it. Suggested-by: Oleg Nesterov Signed-off-by: Anton Vorontsov Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/kernel/smp.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index b735521a4a54..2c7217d971db 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -109,7 +109,6 @@ static void percpu_timer_stop(void); int __cpu_disable(void) { unsigned int cpu = smp_processor_id(); - struct task_struct *p; int ret; ret = platform_cpu_disable(cpu); @@ -139,12 +138,7 @@ int __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; }