On 15.08.2017 17:09, Eric Dumazet wrote:
On Tue, 2017-08-15 at 16:37 +0300, Konstantin Khlebnikov wrote:
When sfq_enqueue() drops head packet or packet from another queue it
have to update backlog at upper qdiscs too.
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
---
net/sched/sch_sfq.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index f80ea2cc5f1f..82469ef9655e 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -437,6 +437,7 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct
sk_buff **to_free)
qdisc_drop(head, sch, to_free);
slot_queue_add(slot, skb);
+ qdisc_tree_reduce_backlog(sch, 0, delta);
return NET_XMIT_CN;
}
@@ -468,8 +469,10 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
/* 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);
Are you sure you have tested this patch ?
Nope. I'm not sure. But we have something similar in our 4.4 kernel for a while.
Also fq_codel and pfifo_head_drop do something similar tho this.
Probably this might crash without "[PATCH 1/2] net_sched: call qlen_notify only if
child qdisc is empty".
I hadn't tested them separately.
