Re: [patch net-next v2 01/12] flow_offload: Introduce offload of HW stats type

[Jiri Pirko <jiri@resnulli.us>]

Tue, Mar 03, 2020 at 08:13:23PM CET, ecree@solarflare.com wrote:
>On 28/02/2020 17:24, Jiri Pirko wrote:
>> From: Jiri Pirko <jiri@mellanox.com>
>>
>> Initially, pass "ANY" (struct is zeroed) to the drivers as that is the
>> current implicit value coming down to flow_offload. Add a bool
>> indicating that entries have mixed HW stats type.
>>
>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>> ---
>> v1->v2:
>> - moved to actions
>> - add mixed bool
>> ---
>>  include/net/flow_offload.h | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
>> index 4e864c34a1b0..eee1cbc5db3c 100644
>> --- a/include/net/flow_offload.h
>> +++ b/include/net/flow_offload.h
>> @@ -154,6 +154,10 @@ enum flow_action_mangle_base {
>>  	FLOW_ACT_MANGLE_HDR_TYPE_UDP,
>>  };
>>  
>> +enum flow_action_hw_stats_type {
>> +	FLOW_ACTION_HW_STATS_TYPE_ANY,
>> +};
>> +
>>  typedef void (*action_destr)(void *priv);
>>  
>>  struct flow_action_cookie {
>> @@ -168,6 +172,7 @@ void flow_action_cookie_destroy(struct flow_action_cookie *cookie);
>>  
>>  struct flow_action_entry {
>>  	enum flow_action_id		id;
>> +	enum flow_action_hw_stats_type	hw_stats_type;
>>  	action_destr			destructor;
>>  	void				*destructor_priv;
>>  	union {
>> @@ -228,6 +233,7 @@ struct flow_action_entry {
>>  };
>>  
>>  struct flow_action {
>> +	bool				mixed_hw_stats_types;
>Some sort of comment in the commit message the effect that this will
> be set in patch #12 would be nice (and would have saved me some
> reviewing time looking for it ;)
>Strictly speaking this violates SPOT; I know a helper to calculate
> this 'at runtime' in the driver would have to loop over actions,
> but it's control-plane so performance doesn't matter :grin:

That is what I wanted to avoid.


>I'd suggest something like adding an internal-use-only MIXED value to
> the enum, and then having a helper
> enum flow_action_hw_state_type flow_action_single_stats_type(struct flow_action *action);
> which could return FLOW_ACTION_HW_STATS_TYPE_MIXED or else whichever
> type all the actions have (except that the 'different' check might
> be further complicated to ignore DISABLED, since most
> flow_action_entries will be for TC actions with no .update_stats()
> which thus don't want stats and can use DISABLED to express that).
>That then avoids having to rely on the first entry having the stats
> type (so flow_action_first_entry_get() goes away).

No problem. I can call a helper that would go over the entries from
driver. As you say, it is a slow path.

Will do.


>
>-ed
>>  	unsigned int			num_entries;
>>  	struct flow_action_entry 	entries[0];
>>  };