In case of UDP traffic with datagram length below MTU this gives about 4% performance increase
Signed-off-by: Paolo Abeni <pab...@redhat.com> Suggested-and-Acked-by: Hannes Frederic Sowa <han...@stressinduktion.org> --- v2: codying style cleanup --- net/ipv4/ip_gre.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 7c51c4e..dfa98cc 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -531,9 +531,16 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) 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); -- 1.8.3.1