sch_htb: update backlog as well

We saw qlen!=0 but backlog==0 on our production machine:

qdisc htb 1: dev eth0 root refcnt 2 r2q 10 default 1 direct_packets_stat 0 ver 3.17
 Sent 172680457356 bytes 222469449 pkt (dropped 0, overlimits 123575834 requeues 0)
 backlog 0b 72p requeues 0

The problem is we only count qlen for HTB qdisc but not backlog.
We need to update backlog too when we update qlen, so that we
can at least know the average packet length.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 846a7f98cef96886410e885a0c1c1b03f54f3f13..87b02ed3d5f212cee3e5bf871c71b72b6329a8aa 100644 (file)
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -600,6 +600,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                htb_activate(q, cl);
        }
 
+       qdisc_qstats_backlog_inc(sch, skb);
        sch->q.qlen++;
        return NET_XMIT_SUCCESS;
 }
@@ -889,6 +890,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
 ok:
                qdisc_bstats_update(sch, skb);
                qdisc_unthrottled(sch);
+               qdisc_qstats_backlog_dec(sch, skb);
                sch->q.qlen--;
                return skb;
        }
@@ -955,6 +957,7 @@ static unsigned int htb_drop(struct Qdisc *sch)
                        unsigned int len;
                        if (cl->un.leaf.q->ops->drop &&
                            (len = cl->un.leaf.q->ops->drop(cl->un.leaf.q))) {
+                               sch->qstats.backlog -= len;
                                sch->q.qlen--;
                                if (!cl->un.leaf.q->q.qlen)
                                        htb_deactivate(q, cl);
@@ -984,12 +987,12 @@ static void htb_reset(struct Qdisc *sch)
                        }
                        cl->prio_activity = 0;
                        cl->cmode = HTB_CAN_SEND;
-
                }
        }
        qdisc_watchdog_cancel(&q->watchdog);
        __skb_queue_purge(&q->direct_queue);
        sch->q.qlen = 0;
+       sch->qstats.backlog = 0;
        memset(q->hlevel, 0, sizeof(q->hlevel));
        memset(q->row_mask, 0, sizeof(q->row_mask));
        for (i = 0; i < TC_HTB_NUMPRIO; i++)