On Mon, 2016-06-27 at 12:50 +0200, Eric Dumazet wrote:
> On Mon, 2016-06-27 at 15:24 +0530, Arjun V wrote:
>
> > Applied your patch.
> > The above debug print is not getting invoked, when skb->len is greater than
> > 65536.
>
> Interesting.
>
> It looks like we might have a bug in tcp_shift_skb_data() not respecting
> sk->sk_gso_max_size at all ...
Note that this also means TCP receiver misbehaves and force us to SACK
reneging.
Patch would be :
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8bd9911fdd16..3587efe22864 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2784,6 +2784,10 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
segs = tp->snd_cwnd - tcp_packets_in_flight(tp);
if (segs <= 0)
return;
+ /* In case tcp_shift_skb_data() have aggregated large skbs,
+ * we need to make sure not sending too big TSO packets.
+ */
+ segs = min_t(int, segs, tp->gso_segs);
if (fwd_rexmitting) {
begin_fwd:
