| From ea1f7f45630c2bbe53cd65583524d954eeb5d91f Mon Sep 17 00:00:00 2001 |
| From: Vinicius Costa Gomes <vinicius.gomes@intel.com> |
| Date: Mon, 14 Oct 2019 13:38:22 -0700 |
| Subject: [PATCH] sched: etf: Fix ordering of packets with same txtime |
| |
| commit 28aa7c86c2b49f659c8460a89e53b506c45979bb upstream. |
| |
| When a application sends many packets with the same txtime, they may |
| be transmitted out of order (different from the order in which they |
| were enqueued). |
| |
| This happens because when inserting elements into the tree, when the |
| txtime of two packets are the same, the new packet is inserted at the |
| left side of the tree, causing the reordering. The only effect of this |
| change should be that packets with the same txtime will be transmitted |
| in the order they are enqueued. |
| |
| The application in question (the AVTP GStreamer plugin, still in |
| development) is sending video traffic, in which each video frame have |
| a single presentation time, the problem is that when packetizing, |
| multiple packets end up with the same txtime. |
| |
| The receiving side was rejecting packets because they were being |
| received out of order. |
| |
| Fixes: 25db26a91364 ("net/sched: Introduce the ETF Qdisc") |
| Reported-by: Ederson de Souza <ederson.desouza@intel.com> |
| Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/net/sched/sch_etf.c b/net/sched/sch_etf.c |
| index db0c2ba1d156..b244881d2b9a 100644 |
| --- a/net/sched/sch_etf.c |
| +++ b/net/sched/sch_etf.c |
| @@ -171,7 +171,7 @@ static int etf_enqueue_timesortedlist(struct sk_buff *nskb, struct Qdisc *sch, |
| |
| parent = *p; |
| skb = rb_to_skb(parent); |
| - if (ktime_after(txtime, skb->tstamp)) { |
| + if (ktime_compare(txtime, skb->tstamp) >= 0) { |
| p = &parent->rb_right; |
| leftmost = false; |
| } else { |
| -- |
| 2.7.4 |
| |
