Re: [dpdk-dev] [PATCH v1 1/5] eventdev: rx_adapter: add support to configure event buffer size

[Jerin Jacob <jerinjacobk@gmail.com>]

On Sat, Sep 18, 2021 at 6:41 PM Naga Harish K S V
<s.v.naga.harish.k@intel.com> wrote:
>
> Currently Rx event buffer is static array
> with a default size of 192(6*BATCH_SIZE).
>
> ``rte_event_eth_rx_adapter_create2`` api is added which takes
> ``struct rte_event_eth_rx_adapter_params`` to configure event
> buffer size in addition other params . The event buffer is
> allocated dynamically at run time aligned to BATCH_SIZE + 2*BATCH_SIZE.
>
> Signed-off-by: Naga Harish K S V <s.v.naga.harish.k@intel.com>
> Signed-off-by: Ganapati Kundapura <ganapati.kundapura@intel.com>
> ---
>
> +/**
> + * A structure to hold adapter config params
> + */
> +struct rte_event_eth_rx_adapter_params {
> +       uint16_t event_buf_size;
> +       /**< size of event buffer for the adapter */

See below.

> +};
> +
>  /**
>   *
>   * Callback function invoked by the SW adapter before it continues
> @@ -330,6 +339,40 @@ int rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
>                                 rte_event_eth_rx_adapter_conf_cb conf_cb,
>                                 void *conf_arg);
>
> +/**
> + * Create a new ethernet Rx event adapter with the specified identifier.
> + * This function allocates Rx adapter event buffer with the size specified
> + * in rxa_params aligned to BATCH_SIZE plus (BATCH_SIZE+BATCH_SIZE) and
> + * uses an internal configuration function that creates an event port.

This function may use for adding another
rte_event_eth_rx_adapter_params:: value.
So semantics of rte_event_eth_rx_adapter_params::event_buf_size you
can document at
in that structure.  This function,  you can tell it adapter creation
varint with parameters or so
See below.

> + * This default function reconfigures the event device with an
> + * additional event port and setups up the event port using the port config
> + * parameter passed into this function. In case the application needs more
> + * control in configuration of the service, it should use the
> + * rte_event_eth_rx_adapter_create_ext() version.
> + *
> + * @param id
> + *  The identifier of the ethernet Rx event adapter.
> + *
> + * @param dev_id
> + *  The identifier of the event device to configure.
> + *
> + * @param rxa_params
> + *  Pointer to struct rte_event_eth_rx_adapter_params containing
> + *  size to allocate rx event buffer.

Value NULL is allowed to represent the default values or so.

> + *
> + * @param port_config
> + *  Argument of type *rte_event_port_conf* that is passed to the conf_cb
> + *  function.
> + *
> + * @return
> + *   - 0: Success
> + *   - <0: Error code on failure
> + */
> +__rte_experimental
> +int rte_event_eth_rx_adapter_create2(uint8_t id, uint8_t dev_id,
> +                       struct rte_event_eth_rx_adapter_params *rxa_params,
> +                       struct rte_event_port_conf *port_config);

Couple of suggestion on API name and prototype:
- I think, we can remove 2 version and give more meaningful,name like
rte_event_eth_rx_adapter_create_with_param() or so

- Keep new parameter as last to have better compatibility i.e
rte_event_eth_rx_adapter_create_with_param(uint8_t id, uint8_t dev_id,
struct rte_event_port_conf *port_config, struct
rte_event_eth_rx_adapter_params *rxa_params)