qdisc_qstats_qlen_backlog
qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
qdisc_qstats_qlen_backlog(qdisc, &qlen, &backlog);
qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
qdisc_qstats_qlen_backlog(cl->leaf.q, &qlen, &qs.backlog);