From: Paolo Abeni Date: Wed, 23 Dec 2015 15:54:27 +0000 (+0100) Subject: geneve: initialize needed_headroom X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=184fc8b5ee601cd83dbbdf3e6cfec5f5b8d3b41a;p=deliverable%2Flinux.git geneve: initialize needed_headroom Currently the needed_headroom field for the geneve device is left to the default value. This patch set it to space required for basic geneve encapsulation, so that we can avoid the skb head re-allocation on xmit. This give a 6% speedup for unsegment traffic on geneve tunnel. v1 -> v2: - add ETH_HLEN for the lower device to the needed headroom Signed-off-by: Paolo Abeni Acked-by: Hannes Frederic Sowa Acked-by: John W. Linville Signed-off-by: David S. Miller --- diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index c2b79f5d1c89..58efdec12f30 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -1155,7 +1155,7 @@ static int geneve_configure(struct net *net, struct net_device *dev, struct geneve_net *gn = net_generic(net, geneve_net_id); struct geneve_dev *t, *geneve = netdev_priv(dev); bool tun_collect_md, tun_on_same_port; - int err; + int err, encap_len; if (!remote) return -EINVAL; @@ -1187,6 +1187,14 @@ static int geneve_configure(struct net *net, struct net_device *dev, if (t) return -EBUSY; + /* make enough headroom for basic scenario */ + encap_len = GENEVE_BASE_HLEN + ETH_HLEN; + if (remote->sa.sa_family == AF_INET) + encap_len += sizeof(struct iphdr); + else + encap_len += sizeof(struct ipv6hdr); + dev->needed_headroom = encap_len + ETH_HLEN; + if (metadata) { if (tun_on_same_port) return -EPERM;