tcp: do not set queue_mapping on SYNACK
At the time of commit fff326990789 ("tcp: reflect SYN queue_mapping into
SYNACK packets") we had little ways to cope with SYN floods.
We no longer need to reflect incoming skb queue mappings, and instead
can pick a TX queue based on cpu cooking the SYNACK, with normal XPS
affinities.
Note that all SYNACK retransmits were picking TX queue 0, this no longer
is a win given that SYNACK rtx are now distributed on all cpus.
Signed-off-by: Eric Dumazet <edumazet@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 6e79fcb..19adedb 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3518,7 +3518,7 @@
int res;
tcp_rsk(req)->txhash = net_tx_rndhash();
- res = af_ops->send_synack(sk, NULL, &fl, req, 0, NULL, true);
+ res = af_ops->send_synack(sk, NULL, &fl, req, NULL, true);
if (!res) {
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);