Re: [dpdk-dev] [PATCH v2] doc: announce ABI change for pktmbuf pool create API

[Hemant Agrawal <hemant.agrawal@nxp.com>]

On 12/18/2017 7:21 PM, Wiles, Keith wrote:
>
>
>> On Dec 15, 2017, at 4:41 AM, Hemant Agrawal <hemant.agrawal@nxp.com> wrote:
>>
>> Introduce a new argument ops_name in rte_mempool_set_ops_byname
>> for allowing the application to optionally specify the mempool ops.
>>
>> Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
>> ---
>> v2: fix checkpatch error
>>
>> doc/guides/rel_notes/deprecation.rst | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
>> index 13e8543..968ca14 100644
>> --- a/doc/guides/rel_notes/deprecation.rst
>> +++ b/doc/guides/rel_notes/deprecation.rst
>> @@ -53,3 +53,6 @@ Deprecation Notices
>>
>> * librte_meter: The API will change to accommodate configuration profiles.
>>   Most of the API functions will have an additional opaque parameter.
>> +
>> +* librte_mbuf: a new optional parameter for representing name of mempool_ops
>> +  will be added to the API ``rte_pktmbuf_pool_create``.
>
>
> Sorry, for the late response I was on vacation.
>
> My question is why do we need to change rte_pktmbuf_pool_create ABI yet again, why could we not add a new API to just set the name of the pool after it is created. This would allow all current applications to work without any ABI breakage and only require adding a new API call for anyone that wants the name. The rte_pktmbuf_pool_create() routine could assign a default name or some incrementing style name as the default. e.g. ‘pktmbuf_%d’ with a static incrementing variable or whatever you like.
>
> Sorry if this was asked and answered before.
>

I understand the concerns.

However, the new API to just set the name will not work post create.
rte_pktmbuf_pool_create is a wrapper API, which complete the mempool 
configuration on the basis default mempool_ops.

The idea proposed is to create pktmbuf pool from a specific mempool 
(ops_name).

We can leave "rte_pktmbuf_pool_create" as it is.
and create another similar API with e.g. 
"rte_pktmbuf_pool_create_specific", which will also take ops_name as 
argument.  (We can combine the internal implementation with NULL 
ops_name for rte_pktmbuf_pool_create.)

This way we will have flexibility for the applications looking for 
pktmbufs from a specific mempool.

any thoughts?

Hemant

>> --
>> 2.7.4
>>
>
> Regards,
> Keith
>