Re: [net-next sample action optimization v2 1/4] openvswitch: Deferred fifo API change.

[Andy Zhou]

On Thu, Mar 16, 2017 at 10:28 AM, Pravin Shelar  wrote:
> On Tue, Mar 14, 2017 at 4:08 PM, Andy Zhou  wrote:
>> add_deferred_actions() API currently requires actions to be passed in
>> as a fully encoded netlink message. So far both 'sample' and 'recirc'
>> actions happens to carry actions as fully encoded netlink messages.
>> However, this requirement is more restrictive than necessary, future
>> patch will need to pass in action lists that are not fully encoded
>> by themselves.
>
> It is not obvious why this change is required?
> can you explain it.

The original 'attr' requires a nested netlink message for the callee
to get the size of
the actions list.  In the sample case, since we rewrite sample into an
internal format that
does not have actions encoded as a nested netlink, we will need to
pass both pointer
to the first action, and the size of the actions list.

Re: [net-next sample action optimization v2 1/4] openvswitch: Deferred fifo API change.

[Pravin Shelar]

On Tue, Mar 14, 2017 at 4:08 PM, Andy Zhou  wrote:
> add_deferred_actions() API currently requires actions to be passed in
> as a fully encoded netlink message. So far both 'sample' and 'recirc'
> actions happens to carry actions as fully encoded netlink messages.
> However, this requirement is more restrictive than necessary, future
> patch will need to pass in action lists that are not fully encoded
> by themselves.

It is not obvious why this change is required?
can you explain it.

[net-next sample action optimization v2 1/4] openvswitch: Deferred fifo API change.

[Andy Zhou]

add_deferred_actions() API currently requires actions to be passed in
as a fully encoded netlink message. So far both 'sample' and 'recirc'
actions happens to carry actions as fully encoded netlink messages.
However, this requirement is more restrictive than necessary, future
patch will need to pass in action lists that are not fully encoded
by themselves.

Signed-off-by: Andy Zhou 
Acked-by: Joe Stringer 
---
 net/openvswitch/actions.c | 18 +++---
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index c82301c..75182e9 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -51,6 +51,7 @@ static int do_execute_actions(struct datapath *dp, struct 
sk_buff *skb,
 struct deferred_action {
struct sk_buff *skb;
const struct nlattr *actions;
+   int actions_len;
 
/* Store pkt_key clone when creating deferred action. */
struct sw_flow_key pkt_key;
@@ -119,8 +120,9 @@ static struct deferred_action *action_fifo_put(struct 
action_fifo *fifo)
 
 /* Return true if fifo is not full */
 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
-   const struct sw_flow_key 
*key,
-   const struct nlattr *attr)
+   const struct sw_flow_key *key,
+   const struct nlattr *actions,
+   const int actions_len)
 {
struct action_fifo *fifo;
struct deferred_action *da;
@@ -129,7 +131,8 @@ static struct deferred_action *add_deferred_actions(struct 
sk_buff *skb,
da = action_fifo_put(fifo);
if (da) {
da->skb = skb;
-   da->actions = attr;
+   da->actions = actions;
+   da->actions_len = actions_len;
da->pkt_key = *key;
}
 
@@ -966,7 +969,8 @@ static int sample(struct datapath *dp, struct sk_buff *skb,
/* Skip the sample action when out of memory. */
return 0;
 
-   if (!add_deferred_actions(skb, key, a)) {
+   if (!add_deferred_actions(skb, key, nla_data(acts_list),
+ nla_len(acts_list))) {
if (net_ratelimit())
pr_warn("%s: deferred actions limit reached, dropping 
sample action\n",
ovs_dp_name(dp));
@@ -1123,7 +1127,7 @@ static int execute_recirc(struct datapath *dp, struct 
sk_buff *skb,
return 0;
}
 
-   da = add_deferred_actions(skb, key, NULL);
+   da = add_deferred_actions(skb, key, NULL, 0);
if (da) {
da->pkt_key.recirc_id = nla_get_u32(a);
} else {
@@ -1278,10 +1282,10 @@ static void process_deferred_actions(struct datapath 
*dp)
struct sk_buff *skb = da->skb;
struct sw_flow_key *key = >pkt_key;
const struct nlattr *actions = da->actions;
+   int actions_len = da->actions_len;
 
if (actions)
-   do_execute_actions(dp, skb, key, actions,
-  nla_len(actions));
+   do_execute_actions(dp, skb, key, actions, actions_len);
else
ovs_dp_process_packet(skb, key);
} while (!action_fifo_is_empty(fifo));
-- 
1.8.3.1