Re: [dpdk-dev] [PATCH v2] doc: add preferred burst size support

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 02/01/2018 03:48 PM, Shreyansh Jain wrote:
> rte_eth_rx_burst(..,nb_pkts) function has semantic that if return value
> is smaller than requested, application can consider it end of packet
> stream. Some hardware can only support smaller burst sizes which need
> to be advertised. Similar is the case for Tx burst.
>
> This patch adds deprecation notice for rte_eth_dev_info structure as
> two new members, for preferred Rx and Tx burst size would be added -
> impacting the size of the structure.
>
> Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
> ---
> * Refer: http://dpdk.org/dev/patchwork/patch/32112 for context
>
> v2:
>   - fix spelling error in deprecation notice
>
>   doc/guides/rel_notes/deprecation.rst | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index d59ad5988..fdc7656fa 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -59,3 +59,11 @@ Deprecation Notices
>     be added between the producer and consumer structures. The size of the
>     structure and the offset of the fields will remain the same on
>     platforms with 64B cache line, but will change on other platforms.
> +
> +* ethdev:  Currently, if the  rte_eth_rx_burst() function returns a value less
> +  than *nb_pkts*, the application will assume that no more packets are present.
> +  Some of the hw queue based hardware can only support smaller burst for RX
> +  and TX and thus break the expectation of the rx_burst API. Similar is the
> +  case for TX burst. ``rte_eth_dev_info`` will be added with two new
> +  parameters, ``uint16_t pref_rx_burst`` and ``uint16_t pref_tx_burst``,
> +  for preferred RX and TX burst sizes, respectively.

Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>