net_sched: sch_htb: add per class overlimits counter

HTB qdisc overlimits counter is properly increased, but we have no per
class counter, meaning it is difficult to diagnose HTB problems.

This patch adds this counter, visible in "tc -s class show dev eth0",
with current iproute2.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.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 7e148376ba528efabe5a53a09653f9161c264be7..c6d7ae81b41f4e277afb93a3003fefcd3f27de35 100644 (file)
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -142,6 +142,7 @@ struct htb_class {
        struct rb_node          node[TC_HTB_NUMPRIO];   /* node for self or feed tree */
 
        unsigned int drops ____cacheline_aligned_in_smp;
+       unsigned int            overlimits;
 };
 
 struct htb_level {
@@ -533,6 +534,9 @@ htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
        if (new_mode == cl->cmode)
                return;
 
+       if (new_mode == HTB_CANT_SEND)
+               cl->overlimits++;
+
        if (cl->prio_activity) {        /* not necessary: speed optimization */
                if (cl->cmode != HTB_CANT_SEND)
                        htb_deactivate_prios(q, cl);
@@ -1143,6 +1147,7 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
        struct htb_class *cl = (struct htb_class *)arg;
        struct gnet_stats_queue qs = {
                .drops = cl->drops,
+               .overlimits = cl->overlimits,
        };
        __u32 qlen = 0;