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>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3b35c3f4d268..944eaca69115 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6236,7 +6236,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
         }
         if (fastopen_sk) {
                 af_ops->send_synack(fastopen_sk, dst, &fl, req,
-                                    skb_get_queue_mapping(skb), &foc, false);
+                                    &foc, false);
                 /* Add the child socket directly into the accept queue */
                 inet_csk_reqsk_queue_add(sk, req, fastopen_sk);
                 sk->sk_data_ready(sk);
@@ -6247,7 +6247,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
                 if (!want_cookie)
                         inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
                 af_ops->send_synack(sk, dst, &fl, req,
-                                    skb_get_queue_mapping(skb), &foc, !want_cookie);
+                                    &foc, !want_cookie);
                 if (want_cookie)
                         goto drop_and_free;
         }