Function tdq_choose

freebsd/kern/sched_ule.c:1376–1401

* Pick the highest priority task we have and return it. */

 * Pick the highest priority task we have and return it.
 */
static struct thread *
tdq_choose(struct tdq *tdq)
{
	struct thread *td;

	TDQ_LOCK_ASSERT(tdq, MA_OWNED);
	td = runq_choose(&tdq->tdq_realtime);
	if (td != NULL)
		return (td);
	td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx);
	if (td != NULL) {
		KASSERT(td->td_priority >= PRI_MIN_BATCH,
		    ("tdq_choose: Invalid priority on timeshare queue %d",
		    td->td_priority));
		return (td);
	}
	td = runq_choose(&tdq->tdq_idle);
	if (td != NULL) {
		KASSERT(td->td_priority >= PRI_MIN_IDLE,
		    ("tdq_choose: Invalid priority on idle queue %d",
		    td->td_priority));
		return (td);
	}

	return (NULL);
}

/*
 * Initialize a thread queue.