openvswitch: Simplify do_execute_actions().

do_execute_actions() implements a worthwhile optimization: in case
an output action is the last action in an action list, skb_clone()
can be avoided by outputing the current skb. However, the
implementation is more complicated than necessary.  This patch
simplify this logic.

Signed-off-by: Andy Zhou <azhou@ovn.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
andy zhou 2017-01-27 13:45:28 -08:00 committed by David S. Miller
parent 6d45408db1
commit 5b8784aaf2
1 changed files with 21 additions and 23 deletions

View File

@ -1141,12 +1141,6 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *attr, int len)
{
/* Every output action needs a separate clone of 'skb', but the common
* case is just a single output action, so that doing a clone and
* then freeing the original skbuff is wasteful. So the following code
* is slightly obscure just to avoid that.
*/
int prev_port = -1;
const struct nlattr *a;
int rem;
@ -1154,20 +1148,28 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
a = nla_next(a, &rem)) {
int err = 0;
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, key);
OVS_CB(skb)->cutlen = 0;
prev_port = -1;
}
switch (nla_type(a)) {
case OVS_ACTION_ATTR_OUTPUT:
prev_port = nla_get_u32(a);
case OVS_ACTION_ATTR_OUTPUT: {
int port = nla_get_u32(a);
struct sk_buff *clone;
/* Every output action needs a separate clone
* of 'skb', In case the output action is the
* last action, cloning can be avoided.
*/
if (nla_is_last(a, rem)) {
do_output(dp, skb, port, key);
/* 'skb' has been used for output.
*/
return 0;
}
clone = skb_clone(skb, GFP_ATOMIC);
if (clone)
do_output(dp, clone, port, key);
OVS_CB(skb)->cutlen = 0;
break;
}
case OVS_ACTION_ATTR_TRUNC: {
struct ovs_action_trunc *trunc = nla_data(a);
@ -1257,11 +1259,7 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
}
}
if (prev_port != -1)
do_output(dp, skb, prev_port, key);
else
consume_skb(skb);
consume_skb(skb);
return 0;
}