Re: [dpdk-dev] [PATCH] eventdev: Fix links_map initialization

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

On Wed, Mar 01, 2017 at 10:47:36PM -0600, Gage Eads wrote:
> This patch initializes the links_map array entries to
> EVENT_QUEUE_SERVICE_PRIORITY_INVALID, as expected by
> rte_event_port_links_get().
> 
> Signed-off-by: Gage Eads <gage.eads@intel.com>
> ---
>  lib/librte_eventdev/rte_eventdev.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_eventdev/rte_eventdev.c b/lib/librte_eventdev/rte_eventdev.c
> index 68bfc3b..b8cd92b 100644
> --- a/lib/librte_eventdev/rte_eventdev.c
> +++ b/lib/librte_eventdev/rte_eventdev.c
> @@ -190,6 +190,8 @@ rte_event_dev_queue_config(struct rte_eventdev *dev, uint8_t nb_queues)
>  	return 0;
>  }
>  
> +#define EVENT_QUEUE_SERVICE_PRIORITY_INVALID (0xdead)
> +
>  static inline int
>  rte_event_dev_port_config(struct rte_eventdev *dev, uint8_t nb_ports)
>  {
> @@ -251,6 +253,9 @@ rte_event_dev_port_config(struct rte_eventdev *dev, uint8_t nb_ports)
>  					"nb_ports %u", nb_ports);
>  			return -(ENOMEM);
>  		}
> +		for (i = 0; i < nb_ports * RTE_EVENT_MAX_QUEUES_PER_DEV; i++)
> +			dev->data->links_map[i] =
> +				EVENT_QUEUE_SERVICE_PRIORITY_INVALID;
>  	} else if (dev->data->ports != NULL && nb_ports != 0) {/* re-config */
>  		RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->port_release, -ENOTSUP);
>  
> @@ -305,6 +310,10 @@ rte_event_dev_port_config(struct rte_eventdev *dev, uint8_t nb_ports)
>  
>  		if (nb_ports > old_nb_ports) {
>  			uint8_t new_ps = nb_ports - old_nb_ports;
> +			unsigned int old_links_map_end =
> +				old_nb_ports * RTE_EVENT_MAX_QUEUES_PER_DEV;
> +			unsigned int links_map_end =
> +				nb_ports * RTE_EVENT_MAX_QUEUES_PER_DEV;
>  
>  			memset(ports + old_nb_ports, 0,
>  				sizeof(ports[0]) * new_ps);
> @@ -312,9 +321,9 @@ rte_event_dev_port_config(struct rte_eventdev *dev, uint8_t nb_ports)
>  				sizeof(ports_dequeue_depth[0]) * new_ps);
>  			memset(ports_enqueue_depth + old_nb_ports, 0,
>  				sizeof(ports_enqueue_depth[0]) * new_ps);
> -			memset(links_map +
> -				(old_nb_ports * RTE_EVENT_MAX_QUEUES_PER_DEV),
> -				0, sizeof(ports_enqueue_depth[0]) * new_ps);
> +			for (i = old_links_map_end; i < links_map_end; i++)
> +				links_map[i] =
> +					EVENT_QUEUE_SERVICE_PRIORITY_INVALID;

rte_event_port_setup() has rte_event_port_unlink() at the end of the
function. On rte_event_port_unlink, we are doing the same
operation(writing EVENT_QUEUE_SERVICE_PRIORITY_INVALID) and
rte_event_port_links_get() should be called after rte_event_dev_start(),
If so, Do you still think this duplicates writes are required? or Do you
have any other call sequence in mind?

---------------------------- Description from header file-----------------
The functions exported by the application Event API to setup a device
designated by its device identifier must be invoked in the following order:
    - rte_event_dev_configure()
    - rte_event_queue_setup()
    - rte_event_port_setup()
    - rte_event_port_link()
    - rte_event_dev_start()

Then, the application can invoke, in any order, the functions
exported by the Event API to schedule events, dequeue events, enqueue events,
change event queue(s) to event port [un]link establishment and so on.

Application may use rte_event_[queue/port]_default_conf_get() to get the
default configuration to set up an event queue or event port by
overriding few default values.

If the application wants to change the configuration (i.e. call
rte_event_dev_configure(), rte_event_queue_setup(), or
rte_event_port_setup()), it must call rte_event_dev_stop() first to stop the
device and then do the reconfiguration before calling rte_event_dev_start()
again. The schedule, enqueue and dequeue functions should not be invoked
when the device is stopped.
-----------------------------------------------------------------------------



>  		}
>  
>  		dev->data->ports = ports;
> @@ -815,8 +824,6 @@ rte_event_port_link(uint8_t dev_id, uint8_t port_id,
>  	return diag;
>  }
>  
> -#define EVENT_QUEUE_SERVICE_PRIORITY_INVALID (0xdead)
> -
>  int
>  rte_event_port_unlink(uint8_t dev_id, uint8_t port_id,
>  		      uint8_t queues[], uint16_t nb_unlinks)
> -- 
> 2.7.4
>