tcp: xps: fix reordering issues
commit 3853b5841c01a ("xps: Improvements in TX queue selection")
introduced ooo_okay flag, but the condition to set it is slightly wrong.
In our traces, we have seen ACK packets being received out of order,
and RST packets sent in response.
We should test if we have any packets still in host queue.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 536d409..ec335fa 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -874,11 +874,13 @@
&md5);
tcp_header_size = tcp_options_size + sizeof(struct tcphdr);
- if (tcp_packets_in_flight(tp) == 0) {
+ if (tcp_packets_in_flight(tp) == 0)
tcp_ca_event(sk, CA_EVENT_TX_START);
- skb->ooo_okay = 1;
- } else
- skb->ooo_okay = 0;
+
+ /* if no packet is in qdisc/device queue, then allow XPS to select
+ * another queue.
+ */
+ skb->ooo_okay = sk_wmem_alloc_get(sk) == 0;
skb_push(skb, tcp_header_size);
skb_reset_transport_header(skb);