udp: gro behind static key
Avoid the socket lookup cost in udp_gro_receive if no socket has a
udp tunnel callback configured.
udp_sk(sk)->gro_receive requires a registration with
setup_udp_tunnel_sock, which enables the static key.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5fc4beb..1bec220 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1889,7 +1889,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
return 0;
}
-static DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
+DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
void udp_encap_enable(void)
{
static_branch_enable(&udp_encap_needed_key);
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 0c0522b..802f2bc 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -405,7 +405,7 @@ static struct sk_buff *udp4_gro_receive(struct list_head *head,
{
struct udphdr *uh = udp_gro_udphdr(skb);
- if (unlikely(!uh))
+ if (unlikely(!uh) || !static_branch_unlikely(&udp_encap_needed_key))
goto flush;
/* Don't bother verifying checksum if we're going to flush anyway. */