@@ -35,6 +35,7 @@ struct pcpu_vstats {
struct veth_priv {
struct net_device __rcu *peer;
atomic64_t dropped;
+ unsigned requested_headroom;
};
/*
@@ -271,6 +272,29 @@ static int veth_get_iflink(const struct net_device *dev)
return iflink;
}
+static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
+{
+ struct veth_priv *peer_priv, *priv = netdev_priv(dev);
+ struct net_device *peer;
+
+ if (new_hr < 0)
+ new_hr = 0;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ if (unlikely(!peer))
+ goto out;
+
+ peer_priv = netdev_priv(peer);
+ priv->requested_headroom = new_hr;
+ new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
+ dev->needed_headroom = new_hr;
+ peer->needed_headroom = new_hr;
+
+out:
+ rcu_read_unlock();
+}
+
static const struct net_device_ops veth_netdev_ops = {
.ndo_init = veth_dev_init,
.ndo_open = veth_open,
@@ -285,6 +309,7 @@ static const struct net_device_ops veth_netdev_ops = {
#endif
.ndo_get_iflink = veth_get_iflink,
.ndo_features_check = passthru_features_check,
+ .ndo_set_rx_headroom = veth_set_rx_headroom,
};
#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
@@ -301,6 +326,7 @@ static void veth_setup(struct net_device *dev)
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
dev->priv_flags |= IFF_NO_QUEUE;
+ dev->priv_flags |= IFF_PHONY_HEADROOM;
dev->netdev_ops = &veth_netdev_ops;
dev->ethtool_ops = &veth_ethtool_ops;
The rx headroom for veth dev is the peer device needed_headroom. Avoid ping-pong updates setting the private flag IFF_PHONY_HEADROOM. This avoids skb head reallocation when forwarding from a veth dev towards a device adding some kind of encapsulation. When transmitting frames below the MTU size towards a vxlan device, this gives about 10% performance speed-up when OVS is used to connect the veth and the vxlan device and a little more when using a plain Linux bridge. Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- drivers/net/veth.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)