qh_hmax
qp->qh_qmax, qp->qh_hmax) < 0)
qp->qh_qmax, qp->qh_hmax) < 0)
qp->qh_hmax = 1;
ASSERT(qp->qh_hlen == cnt && qp->qh_hmax >= cnt);
MAXINCR(qp->qh_hmax, qp->qh_hlen);
qp->qh_hmax = 1;