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 <[email protected]> Cc: "Srivatsa S. Bhat" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Anton Vorontsov <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
