From: Jakub Kicinski Date: Wed, 29 May 2024 16:25:27 +0000 (-0700) Subject: net: count drops due to missing qdisc as dev->tx_drops X-Git-Tag: v6.11-rc1~163^2~263 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4fdb6b6063f07d959a1c52a2ee580afc4da34e2d;p=thirdparty%2Flinux.git net: count drops due to missing qdisc as dev->tx_drops Catching and debugging missing qdiscs is pretty tricky. When qdisc is deleted we replace it with a noop qdisc, which silently drops all the packets. Since the noop qdisc has a single static instance we can't count drops at the qdisc level. Count them as dev->tx_drops. ip netns add red ip link add type veth peer netns red ip link set dev veth0 up ip -netns red link set dev veth0 up ip a a dev veth0 10.0.0.1/24 ip -netns red a a dev veth0 10.0.0.2/24 ping -c 2 10.0.0.2 # 2 packets transmitted, 2 received, 0% packet loss, time 1031ms ip -s link show dev veth0 # TX: bytes packets errors dropped carrier collsns # 1314 17 0 0 0 0 tc qdisc replace dev veth0 root handle 1234: mq tc qdisc replace dev veth0 parent 1234:1 pfifo tc qdisc del dev veth0 parent 1234:1 ping -c 2 10.0.0.2 # 2 packets transmitted, 0 received, 100% packet loss, time 1034ms ip -s link show dev veth0 # TX: bytes packets errors dropped carrier collsns # 1314 17 0 3 0 0 Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20240529162527.3688979-1-kuba@kernel.org Signed-off-by: Paolo Abeni --- diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 2a637a17061b9..1417f1991452f 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -633,6 +633,7 @@ EXPORT_SYMBOL_GPL(netif_carrier_event); static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc, struct sk_buff **to_free) { + dev_core_stats_tx_dropped_inc(skb->dev); __qdisc_drop(skb, to_free); return NET_XMIT_CN; }