From: Eric Dumazet <edumazet@google.com>
Date: Mon, 18 Sep 2017 12:36:22 -0700
Subject: net_sched: sch_htb: add per class overlimits counter
Patch-mainline: v4.15-rc1
Git-commit: 3c75f6ee139d464351f8ab77a042dd3635769d98
References: bsc#1109837

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/sch_htb.c |    5 +++++
 1 file changed, 5 insertions(+)

--- 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 *
 	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,
 	struct htb_class *cl = (struct htb_class *)arg;
 	struct gnet_stats_queue qs = {
 		.drops = cl->drops,
+		.overlimits = cl->overlimits,
 	};
 	__u32 qlen = 0;