Q_REQUEUE_PI_WAIT
old != Q_REQUEUE_PI_WAIT);
WARN_ON_ONCE(old != Q_REQUEUE_PI_WAIT);
if (unlikely(old == Q_REQUEUE_PI_WAIT))
new = Q_REQUEUE_PI_WAIT;
atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT,
(void)atomic_cond_read_relaxed(&q->requeue_state, VAL != Q_REQUEUE_PI_WAIT);