ovs: propagate per dp max headroom to all vports
authorPaolo Abeni <pabeni@redhat.com>
Fri, 26 Feb 2016 09:45:39 +0000 (10:45 +0100)
committerDavid S. Miller <davem@davemloft.net>
Tue, 1 Mar 2016 20:54:30 +0000 (15:54 -0500)
This patch implements bookkeeping support to compute the maximum
headroom for all the devices in each datapath. When said value
changes, the underlying devs are notified via the
ndo_set_rx_headroom method.

This also increases the internal vports xmit performance.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/openvswitch/datapath.c
net/openvswitch/datapath.h
net/openvswitch/vport-internal_dev.c

index c4e8455d5d56bbb9d701cff6dd21bb3793860f98..e6a7d494df24dbf58a9d177693d07c164fb84e3a 100644 (file)
@@ -1908,6 +1908,29 @@ static struct vport *lookup_vport(struct net *net,
                return ERR_PTR(-EINVAL);
 }
 
+/* Called with ovs_mutex */
+static void update_headroom(struct datapath *dp)
+{
+       unsigned dev_headroom, max_headroom = 0;
+       struct net_device *dev;
+       struct vport *vport;
+       int i;
+
+       for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
+               hlist_for_each_entry_rcu(vport, &dp->ports[i], dp_hash_node) {
+                       dev = vport->dev;
+                       dev_headroom = netdev_get_fwd_headroom(dev);
+                       if (dev_headroom > max_headroom)
+                               max_headroom = dev_headroom;
+               }
+       }
+
+       dp->max_headroom = max_headroom;
+       for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++)
+               hlist_for_each_entry_rcu(vport, &dp->ports[i], dp_hash_node)
+                       netdev_set_rx_headroom(vport->dev, max_headroom);
+}
+
 static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
@@ -1973,6 +1996,12 @@ restart:
 
        err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
                                      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
+
+       if (netdev_get_fwd_headroom(vport->dev) > dp->max_headroom)
+               update_headroom(dp);
+       else
+               netdev_set_rx_headroom(vport->dev, dp->max_headroom);
+
        BUG_ON(err < 0);
        ovs_unlock();
 
@@ -2039,8 +2068,10 @@ exit_unlock_free:
 
 static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
 {
+       bool must_update_headroom = false;
        struct nlattr **a = info->attrs;
        struct sk_buff *reply;
+       struct datapath *dp;
        struct vport *vport;
        int err;
 
@@ -2062,7 +2093,16 @@ static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
        err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
                                      info->snd_seq, 0, OVS_VPORT_CMD_DEL);
        BUG_ON(err < 0);
+
+       /* the vport deletion may trigger dp headroom update */
+       dp = vport->dp;
+       if (netdev_get_fwd_headroom(vport->dev) == dp->max_headroom)
+               must_update_headroom = true;
+       netdev_reset_rx_headroom(vport->dev);
        ovs_dp_detach_port(vport);
+
+       if (must_update_headroom)
+               update_headroom(dp);
        ovs_unlock();
 
        ovs_notify(&dp_vport_genl_family, reply, info);
index 67bdecd9fdc1f2b0544c2081aa1a557b16e0063a..427e39a045cf2d98aff3add0b4a9f47c50c467f4 100644 (file)
@@ -68,6 +68,8 @@ struct dp_stats_percpu {
  * ovs_mutex and RCU.
  * @stats_percpu: Per-CPU datapath statistics.
  * @net: Reference to net namespace.
+ * @max_headroom: the maximum headroom of all vports in this datapath; it will
+ * be used by all the internal vports in this dp.
  *
  * Context: See the comment on locking at the top of datapath.c for additional
  * locking information.
@@ -89,6 +91,8 @@ struct datapath {
        possible_net_t net;
 
        u32 user_features;
+
+       u32 max_headroom;
 };
 
 /**
index ec76398a792fbb7451c53b958304a2e001704604..83a5534abd312b34d8e0171981645f32691cdf39 100644 (file)
@@ -138,6 +138,11 @@ internal_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats)
        return stats;
 }
 
+void internal_set_rx_headroom(struct net_device *dev, int new_hr)
+{
+       dev->needed_headroom = new_hr;
+}
+
 static const struct net_device_ops internal_dev_netdev_ops = {
        .ndo_open = internal_dev_open,
        .ndo_stop = internal_dev_stop,
@@ -145,6 +150,7 @@ static const struct net_device_ops internal_dev_netdev_ops = {
        .ndo_set_mac_address = eth_mac_addr,
        .ndo_change_mtu = internal_dev_change_mtu,
        .ndo_get_stats64 = internal_get_stats,
+       .ndo_set_rx_headroom = internal_set_rx_headroom,
 };
 
 static struct rtnl_link_ops internal_dev_link_ops __read_mostly = {
@@ -158,7 +164,8 @@ static void do_setup(struct net_device *netdev)
        netdev->netdev_ops = &internal_dev_netdev_ops;
 
        netdev->priv_flags &= ~IFF_TX_SKB_SHARING;
-       netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_OPENVSWITCH;
+       netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_OPENVSWITCH |
+                             IFF_PHONY_HEADROOM;
        netdev->destructor = internal_dev_destructor;
        netdev->ethtool_ops = &internal_dev_ethtool_ops;
        netdev->rtnl_link_ops = &internal_dev_link_ops;
@@ -199,6 +206,7 @@ static struct vport *internal_dev_create(const struct vport_parms *parms)
                err = -ENOMEM;
                goto error_free_netdev;
        }
+       vport->dev->needed_headroom = vport->dp->max_headroom;
 
        dev_net_set(vport->dev, ovs_dp_get_net(vport->dp));
        internal_dev = internal_dev_priv(vport->dev);