net/ipv4: add dst cache support for gre lwtunnels
In case of UDP traffic with datagram length below MTU this
gives about 4% performance increase
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Suggested-and-Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 65748db..917c2c1 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -540,9 +540,16 @@
goto err_free_skb;
key = &tun_info->key;
- rt = gre_get_rt(skb, dev, &fl, key);
- if (IS_ERR(rt))
- goto err_free_skb;
+ rt = !skb->mark ? dst_cache_get_ip4(&tun_info->dst_cache, &fl.saddr) :
+ NULL;
+ if (!rt) {
+ rt = gre_get_rt(skb, dev, &fl, key);
+ if (IS_ERR(rt))
+ goto err_free_skb;
+ if (!skb->mark)
+ dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
+ fl.saddr);
+ }
tunnel_hlen = ip_gre_calc_hlen(key->tun_flags);