net_sched: increment drop counters in qdisc_tree_decrease_qlen()
qdisc_tree_decrease_qlen() is called when some packets are dropped
on a qdisc, and we want to notify parents of qlen changes.
We also can increment parents qdisc qstats drop counters.
This permits more accurate drop counters up to root qdisc.
For example a graft operation typically resets a qdisc
(drops all packets) and call qdisc_tree_decrease_qlen()
Note that callers are responsible for their drop counters.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 2adda7f..cd81505 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -737,9 +737,11 @@
const struct Qdisc_class_ops *cops;
unsigned long cl;
u32 parentid;
+ int drops;
if (n == 0)
return;
+ drops = max_t(int, n, 0);
while ((parentid = sch->parent)) {
if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
return;
@@ -756,6 +758,7 @@
cops->put(sch, cl);
}
sch->q.qlen -= n;
+ sch->qstats.drops += drops;
}
}
EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
