This is a note to let you know that I've just added the patch titled net_sched/sfq: update hierarchical backlog when drop packet to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net_sched-sfq-update-hierarchical-backlog-when-drop-packet.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Aug 24 17:44:02 PDT 2017 From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Date: Tue, 15 Aug 2017 16:37:04 +0300 Subject: net_sched/sfq: update hierarchical backlog when drop packet From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> [ 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@xxxxxxxxxxxxxx> Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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); Patches currently in stable-queue which might be from khlebnikov@xxxxxxxxxxxxxx are queue-4.9/net_sched-remove-warning-from-qdisc_hash_add.patch queue-4.9/net_sched-fix-order-of-queue-length-updates-in-qdisc_replace.patch queue-4.9/net_sched-sfq-update-hierarchical-backlog-when-drop-packet.patch