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>
This commit is contained in:
Paolo Abeni 2016-02-12 15:43:59 +01:00 committed by David S. Miller
parent 468dfffcd7
commit 3c1cb4d260

View File

@ -540,9 +540,16 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
goto err_free_skb;
key = &tun_info->key;
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);