474 		EQUIV(sq->sq_head, sq->sq_tail);			\
478 		EQUIV(sq->sq_head, (sq->sq_flags & SQ_MESSAGES));	\
480 		IMPLY(sq->sq_head != NULL, sq->sq_head->q_sqprev == NULL);\
487 		IMPLY(sq->sq_head == NULL, sq->sq_pri == 0);		\
489 		EQUIV(sq->sq_head, sq->sq_nqueues);			\
490 		if (sq->sq_head == NULL) {				\
491 			sq->sq_head = sq->sq_tail = qp;			\
514 				sq->sq_head = qp;			\
515 				sq->sq_pri = sq->sq_head->q_spri;	\
533 		ASSERT(sq->sq_head != NULL && sq->sq_tail != NULL);	\
537 		ASSERT(qp->q_sqprev != NULL || sq->sq_head == qp);	\
541 			sq->sq_head = qp->q_sqnext;			\
557 		if (sq->sq_head != NULL) {				\
558 			sq->sq_pri = sq->sq_head->q_spri;		\
564 		ASSERT(sq->sq_head != NULL || sq->sq_evhead != NULL ||	\
722 	sq->sq_head = NULL;  in queue_constructor()
795 	ASSERT(sq->sq_head == NULL);  in syncq_destructor()
1305 	    ((qp->q_syncq->sq_head == NULL) &&  in qdetach()
1306 	    (wqp->q_syncq->sq_head == NULL)));  in qdetach()
2169 		    ((rq->q_syncq->sq_head == NULL) &&  in munlink()
2170 		    (_WR(rq)->q_syncq->sq_head == NULL)));  in munlink()
2532 	ASSERT(rq->q_syncq == NULL || (rq->q_syncq->sq_head == NULL &&  in setq()
2534 	ASSERT(wq->q_syncq == NULL || (wq->q_syncq->sq_head == NULL &&  in setq()
2560 	ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL);  in setq()
3467 	ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL);  in freeq()
5651 	ASSERT(sq->sq_head == NULL);  in free_syncq()
6529 		for (qp = sq->sq_head;  in drain_syncq()
6579 	ASSERT((sq->sq_head == NULL) || (flags & SQ_GOAWAY) ||  in drain_syncq()
6580 	    (type & SQ_CI) || sq->sq_head->q_draining);  in drain_syncq()
6910 		if (sq->sq_tail == sq->sq_head) {  in qfill_syncq()
7000 	q = sq->sq_head;  in flush_syncq()
7062 				q = sq->sq_head;  in flush_syncq()