net: openvswitch: select vport upcall portid directly

The commit 69c51582ff786 ("dpif-netlink: don't allocate per
thread netlink sockets"), in Open vSwitch ovs-vswitchd, has
changed the number of allocated sockets to just one per port
by moving the socket array from a per handler structure to
a per datapath one. In the kernel datapath, a vport will have
only one socket in most case, if so select it directly in
fast-path.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/openvswitch/vport.c

@@ -403,8 +403,9 @@ u32 ovs_vport_find_upcall_portid(const struct vport *vport, struct sk_buff *skb)
 
 	ids = rcu_dereference(vport->upcall_portids);
 
-	if (ids->n_ids == 1 && ids->ids[0] == 0)
-		return 0;
+	/* If there is only one portid, select it in the fast-path. */
+	if (ids->n_ids == 1)
+		return ids->ids[0];
 
 	hash = skb_get_hash(skb);
 	ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids);