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>
This commit is contained in:
Andy Zhou 2014-09-08 00:35:02 -07:00 committed by Pravin B Shelar
parent 426cda5cc1
commit 738967b8bf

View File

@ -551,21 +551,14 @@ static int set_sctp(struct sk_buff *skb,
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 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
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;
}