Re: [patch net-next 1/3] team: remove synchronize_rcu() called during queue override change

[Jiri Pirko <jiri@resnulli.us>]

Tue, Jun 11, 2013 at 02:48:45AM CEST, fbl@redhat.com wrote:
>On Mon, Jun 10, 2013 at 05:42:23PM +0200, Jiri Pirko wrote:
>> This patch removes synchronize_rcu() from function
>> __team_queue_override_port_del(). That can be done because it is ok to
>> do list_del_rcu() and list_add_tail_rcu() on the same list_head member
>> without calling synchronize_rcu() in between. A bit of refactoring
>> needed to be done because INIT_LIST_HEAD needed to be removed (to not
>> kill the forward pointer) as well.
>> 
>> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
>> ---
>>  drivers/net/team/team.c | 63 ++++++++++++++++++++++++++++++++++++-------------
>>  1 file changed, 47 insertions(+), 16 deletions(-)
>> 
>[...]
>
>> @@ -1278,17 +1310,16 @@ static int team_queue_id_option_set(struct team *team,
>>  				    struct team_gsetter_ctx *ctx)
>>  {
>>  	struct team_port *port = ctx->info->port;
>> +	u16 new_queue_id = ctx->data.u32_val;
>>  
>> -	if (port->queue_id == ctx->data.u32_val)
>> +	if (port->queue_id == new_queue_id)
>
>Since you're passing new_queue_id to port->queue_id and
>in the other parts you test against !port->queue_id to see
>if it's enable or not, that means queue 0 can't be used.
>
>Maybe I am missing something, but wouldn't be better to
>initialize with -1 and allow 0 to be used as well?

0 means default queue. It's done the same was as in bonding code.

>
>fbl
>
>>  		return 0;
>> -	if (ctx->data.u32_val >= team->dev->real_num_tx_queues)
>> +	if (new_queue_id >= team->dev->real_num_tx_queues)
>>  		return -EINVAL;
>> -	port->queue_id = ctx->data.u32_val;
>> -	team_queue_override_port_refresh(team, port);
>> +	team_queue_override_port_change_queue_id(team, port, new_queue_id);
>>  	return 0;
>>  }
>>  
>