Re: [dpdk-dev] [PATCH] doc: plan splitting the ethdev ops struct

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

On 2/18/2020 5:07 AM, Jerin Jacob wrote:
> On Mon, Feb 17, 2020 at 9:08 PM Ferruh Yigit <ferruh.yigit@intel.com> wrote:
>>
>> For the ABI compatibility it is better to hide internal data structures
>> from the application as much as possible. But because of some inline
>> functions 'struct eth_dev_ops' can't be hidden completely.
>>
>> Plan is to split the 'struct eth_dev_ops' into two as ones used by
>> inline functions and ones not used, and hide the second part that not
>> used by inline functions completely to the application.
> 
> It is a good improvement.  IMO, If anything used in fast-path it
> should be in ``struct rte_eth_dev``
> and rest can completely be moved to internal. In this case, if
> `rte_eth_tx_descriptor_status`
> not used on fastpath, Maybe we don't need to maintain the inline
> status and move completely
> to .c file.

Moving fast-past dev_ops to ``struct rte_eth_dev`` makes sense, also suggested
by Andrew, and will hide the rest.

Those inline dev_ops are datapath related so may be better to keep them as
inline, but not really sure about their users and how much they care about minor
performance impact if we chose to convert them into regular functions.

> 
> Those may be specifics of the work. In general, this change looks good to me.
> 
> Acked-by: Jerin Jacob <jerinj@marvell.com>
> 
> 
> 
> 
> 
>>
>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
>> ---
>> Cc: David Marchand <david.marchand@redhat.com>
>> Cc: Thomas Monjalon <thomas@monjalon.net>
>> Cc: Andrew Rybchenko <arybchenko@solarflare.com>
>> ---
>>  doc/guides/rel_notes/deprecation.rst | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
>> index dfcca87ab..2aa431028 100644
>> --- a/doc/guides/rel_notes/deprecation.rst
>> +++ b/doc/guides/rel_notes/deprecation.rst
>> @@ -72,6 +72,12 @@ Deprecation Notices
>>    In 19.11 PMDs will still update the field even when the offload is not
>>    enabled.
>>
>> +* ethdev: Split the ``struct eth_dev_ops`` struct to hide it as much as possible.
>> +  Currently the ``struct eth_dev_ops`` struct is accessible by the application
>> +  because some inline functions, like ``rte_eth_tx_descriptor_status()``,
>> +  access the struct directly. The struct will be separate in two, the ops used
>> +  by inline functions still will be accessible to user but rest will be hidden.
>> +
>>  * cryptodev: support for using IV with all sizes is added, J0 still can
>>    be used but only when IV length in following structs ``rte_crypto_auth_xform``,
>>    ``rte_crypto_aead_xform`` is set to zero. When IV length is greater or equal
>> --
>> 2.24.1
>>