From 5b8784aaf29be20ba8d363e1124d7436d42ef9bf Mon Sep 17 00:00:00 2001 From: andy zhou Date: Fri, 27 Jan 2017 13:45:28 -0800 Subject: [PATCH] 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 Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/openvswitch/actions.c | 42 ++++++++++++++++++++---------------------- 1 file changed, 20 insertions(+), 22 deletions(-) diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index 514f7bc..efa9a88 100644 --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -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); + switch (nla_type(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; - prev_port = -1; - } - - switch (nla_type(a)) { - case OVS_ACTION_ATTR_OUTPUT: - prev_port = nla_get_u32(a); 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; } -- 2.7.4