From 693525e3bea25cf2ee6cf2b862ba7c148e891df2 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 21 Jul 2009 13:56:38 +0200 Subject: [PATCH] sched: Ensure the migration task doesn't go away during use Like sched_migrate_task(), set_cpus_allowed_ptr() should hold onto the migration thread too. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched.c b/kernel/sched.c index 475138c42548..7f83be35d65c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7078,8 +7078,12 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) { /* Need help from migration thread: drop lock and wait. */ + struct task_struct *mt = rq->migration_thread; + + get_task_struct(mt); task_rq_unlock(rq, &flags); wake_up_process(rq->migration_thread); + put_task_struct(mt); wait_for_completion(&req.done); tlb_migrate_finish(p->mm); return 0;