wait_task_inactive
wait_task_inactive(iit->tsk, TASK_ANY);
wait_task_inactive(ptr->task, TASK_ANY);
extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
if (!wait_task_inactive(p, state)) {
WARN_ON_ONCE(!wait_task_inactive(k, TASK_PARKED));
if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE) || kthread->started) {
WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN)))
if (!wait_task_inactive(tsk, TASK_PARKED))
ncsw = wait_task_inactive(target, state);
unlikely(wait_task_inactive(target, state) != ncsw))