Re: [dpdk-dev] [PATCH] eventdev: add callback for Rx adapter SW transfers

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

-----Original Message-----
> Date: Fri, 8 Jun 2018 23:54:16 +0530
> From: Nikhil Rao <nikhil.rao@intel.com>
> To: jerin.jacob@caviumnetworks.com
> CC: dev@dpdk.org, Nikhil Rao <nikhil.rao@intel.com>
> Subject: [PATCH] eventdev: add callback for Rx adapter SW transfers
> X-Mailer: git-send-email 1.8.3.1
> 
> Add ability for application to register a callback function
> for SW transfers, the callback can decide which packets can
> be enqueued to the event device.
> 
> Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
> ---
>  lib/librte_eventdev/rte_event_eth_rx_adapter.h     | 78 ++++++++++++++++++++++
>  lib/librte_eventdev/rte_event_eth_rx_adapter.c     | 69 +++++++++++++++++--
>  .../prog_guide/event_ethernet_rx_adapter.rst       | 14 ++++
>  lib/librte_eventdev/rte_eventdev_version.map       |  1 +
>  4 files changed, 158 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/librte_eventdev/rte_event_eth_rx_adapter.h b/lib/librte_eventdev/rte_event_eth_rx_adapter.h
> index 97f25e9..23d2ed5 100644
> --- a/lib/librte_eventdev/rte_event_eth_rx_adapter.h
> +++ b/lib/librte_eventdev/rte_event_eth_rx_adapter.h
> @@ -63,6 +63,17 @@
>   * rte_event_eth_rx_adapter_service_id_get() function can be used to retrieve
>   * the service function ID of the adapter in this case.
>   *
> + * For SW based packet transfers, the service function temporarily enqueues

I think, you can mention this case is valid when
!RTE_EVENT_ETH_RX_ADAPTER_CAP_INTERNAL_PORT

> + * mbufs to an event buffer before batch enqueueing these to the event device.
> + * If the buffer fills up, the service function stops dequeueing packets from
> + * the ethernet device. The application may want to monitor the buffer fill
> + * level and instruct the service function to selectively buffer packets
> + * The application may also use some other criteria to decide which packets
> + * should enter the event device even when the event buffer fill level is low.
> + * The rte_event_eth_rx_adapter_cb_register() function allows the
> + * application to register a callback that selects which packets to enqueue
> + * to the event device.
> + *
>   * Note:
>   * 1) Devices created after an instance of rte_event_eth_rx_adapter_create
>   *  should be added to a new instance of the rx adapter.
> @@ -206,6 +217,47 @@ struct rte_event_eth_rx_adapter_stats {
>   * @warning
>   * @b EXPERIMENTAL: this API may change without prior notice
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> + *
> + * Register callback to process Rx packets, this is supported for
> + * SW based packet transfers.
> + * @see rte_event_eth_sw_rx_cb_fn
> + *
> + * @param id
> + *  Adapter identifier.
> + * @param eth_dev_id
> + *  Port identifier of Ethernet device.
> + * @param cb_fn
> + *  Callback function.
> + * @param cb_arg
> + *  Callback arg.
> + * @return
> + *  - 0: Success
> + *  - <0: Error code on failure.
> + */
> +int __rte_experimental
> +rte_event_eth_rx_sw_cb_register(uint8_t id,
> +				uint16_t eth_dev_id,
> +				rte_event_eth_rx_sw_cb_fn cb_fn,
> +				void *cb_arg);


The documentation is using rte_event_eth_rx_adapter_cb_register(),
I think, it is better to keep that name. Remove *_sw_* from normative
DPDK APIs.


> +
>  #ifdef __cplusplus
>  }
>  #endif
> diff --git a/lib/librte_eventdev/rte_eventdev_version.map b/lib/librte_eventdev/rte_eventdev_version.map
> index c3f18d6..6bc81c6 100644
> --- a/lib/librte_eventdev/rte_eventdev_version.map
> +++ b/lib/librte_eventdev/rte_eventdev_version.map
> @@ -109,4 +109,5 @@ EXPERIMENTAL {
>  	rte_event_crypto_adapter_stats_get;
>  	rte_event_crypto_adapter_stats_reset;
>  	rte_event_crypto_adapter_stop;
> +	rte_event_eth_rx_sw_cb_register;

Use alphabetical order.

With above changes:
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

>  };
> -- 
> 1.8.3.1
>