Re: [PATCH] doc: announce ABI change on ethdev

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 5/1/2017 7:58 AM, Shahaf Shuler wrote:
> This is an ABI change notice for DPDK 17.08 in librte_ether
> about changes in rte_eth_txmode structure.
> 
> Currently Tx offloads are enabled by default, and can be disabled
> using ETH_TXQ_FLAGS_NO* flags. This behaviour is not consistent with
> the Rx side where the Rx offloads are disabled by default and enabled
> according to bit field in rte_eth_rxmode structure.
> 
> The proposal is to disable the Tx offloads by default, and provide
> a way for the application to enable them in rte_eth_txmode structure.
> Besides of making the Tx configuration API more consistent for
> applications, PMDs will be able to provide a better out of the
> box performance.
> Finally, as part of the work, the ETH_TXQ_FLAGS_NO* will
> be superseded as well.
> 
> Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
> ---
> looks like this patch has arrived to everyone     
> besides dev@dpdk.org resending it again. sorry for
> the noise.                                        
> ---
>  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 a3e7c720c..0920b4766 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -81,3 +81,11 @@ Deprecation Notices
>  
>    - ``rte_crpytodev_scheduler_mode_get``, replaced by ``rte_cryptodev_scheduler_mode_get``
>    - ``rte_crpytodev_scheduler_mode_set``, replaced by ``rte_cryptodev_scheduler_mode_set``
> +
> +* ethdev: in 17.08 ABI changes are planned:
> +  Tx offloads will no longer be enabled by default.
> +  Instead, the ``rte_eth_txmode`` structure will be extended with bit field to enable
> +  each Tx offload.
> +  Besides of making the Rx/Tx configuration API more consistent for the
> +  application, PMDs will be able to provide a better out of the box performance.

I understand the consistency part, but why PMD performs better when Tx
offload disabled?

> +  as part of the work, ``ETH_TXQ_FLAGS_NO*`` will be superseded as well.
>