openvswitch: refactor do_output() to move NULL check out of fast path (738967b8) · Commits · 戴 / test

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>

net/openvswitch/actions.c

+11 −14

Original line number	Diff line number	Diff line
		@@ -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;

		if (unlikely(!skb))
		return -ENOMEM;

		vport = ovs_vport_rcu(dp, out_port);
		if (unlikely(!vport)) {
		kfree_skb(skb);
		return -ENODEV;
		}
		struct vport *vport = ovs_vport_rcu(dp, out_port);

		if (likely(vport))
		ovs_vport_send(vport, skb);
		return 0;
		else
		kfree_skb(skb);
		}

		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;
		}

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