[PATCH 4.9 06/84] net_sched/sfq: update hierarchical backlog when drop packet

Greg Kroah-Hartman
2017-08-28T08:10:35Z

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

[ Upstream commit 325d5dc3f7e7c2840b65e4a2988c082c2c0025c5 ]

When sfq_enqueue() drops head packet or packet from another queue it
have to update backlog at upper qdiscs too.

Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sched/sch_sfq.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -434,6 +434,7 @@ congestion_drop:
qdisc_drop(head, sch, to_free);

slot_queue_add(slot, skb);
+ qdisc_tree_reduce_backlog(sch, 0, delta);
return NET_XMIT_CN;
}

@@ -465,8 +466,10 @@ enqueue:
/* Return Congestion Notification only if we dropped a packet
* from this flow.
*/
- if (qlen != slot->qlen)
+ if (qlen != slot->qlen) {
+ qdisc_tree_reduce_backlog(sch, 0, dropped - qdisc_pkt_len(skb));
return NET_XMIT_CN;
+ }

/* As we dropped a packet, better let upper stack know this */
qdisc_tree_reduce_backlog(sch, 1, dropped);