openvswitch: refactor do_output() to move NULL check out of fast path
skb_clone() NULL check is implemented in do_output(), as past of the
common (fast) path. Refactoring so that NULL check is done in the
slow path, immediately after skb_clone() is called.
Besides optimization, this change also improves code readability by
making the skb_clone() NULL check consistent within OVS datapath
module.
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 930b1b6..9fd33c0 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -551,21 +551,14 @@
return 0;
}
-static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
+static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
{
- struct vport *vport;
+ struct vport *vport = ovs_vport_rcu(dp, out_port);
- if (unlikely(!skb))
- return -ENOMEM;
-
- vport = ovs_vport_rcu(dp, out_port);
- if (unlikely(!vport)) {
+ if (likely(vport))
+ ovs_vport_send(vport, skb);
+ else
kfree_skb(skb);
- return -ENODEV;
- }
-
- ovs_vport_send(vport, skb);
- return 0;
}
static int output_userspace(struct datapath *dp, struct sk_buff *skb,
@@ -768,8 +761,12 @@
a = nla_next(a, &rem)) {
int err = 0;
- if (prev_port != -1) {
- do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
+ if (unlikely(prev_port != -1)) {
+ struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
+
+ if (out_skb)
+ do_output(dp, out_skb, prev_port);
+
prev_port = -1;
}