On Friday 29 September 2017 12:23 PM, Olivier MATZ wrote:
> On Fri, Sep 29, 2017 at 11:16:20AM +0100, santosh wrote:
>> Hi Olivier,
>>
>>
>> On Friday 29 September 2017 09:32 AM, Olivier MATZ wrote:
>>> On Mon, Sep 25, 2017 at 10:52:31PM +0100, santosh wrote:
>>>> Hi Olivier,
>>>>
>>>>
>>>> On Monday 25 September 2017 08:37 AM, Olivier MATZ wrote:
>>>>
>>>>>> +{
>>>>>> + struct rte_eth_dev *dev;
>>>>>> + const char *tmp;
>>>>>> +
>>>>>> + RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
>>>>>> +
>>>>>> + if (pool == NULL)
>>>>>> + return -EINVAL;
>>>>>> +
>>>>>> + dev = &rte_eth_devices[port_id];
>>>>>> +
>>>>>> + if (*dev->dev_ops->pools_ops_supported == NULL) {
>>>>>> + tmp = rte_eal_mbuf_default_mempool_ops();
>>>>>> + if (!strcmp(tmp, pool))
>>>>>> + return 0;
>>>>>> + else
>>>>>> + return -ENOTSUP;
>>>>> I don't understand why we are comparing with
>>>>> rte_eal_mbuf_default_mempool_ops().
>>>>>
>>>>> It means that the result of the function would be influenced
>>>>> by the parameter given by the user.
>>>> But that will be only for ops not supported case and in that case,
>>>> function _must_ make sure that if inputted param is _default_ops_name
>>>> then function should return ops supported correct info (whether
>>>> returning '0' : Best ops or '1': ops does support
>>>> , this part is arguable.. meaning One can say that default_ops
>>>> ='handle-name' is best possible handle Or
>>>> one of handle which platform supports).
>>>>
>>>>> I think that a PMD that does not implement ->pools_ops_supported
>>>>> should always return 1 (mempool is supported).
>>> I don't agree.
>>> The result of this API (mempool ops supported or not by a PMD)
>>> should not depend on what user asks for.
>>>
>>>> Return 1 says: PMD support this ops..
>>>>
>>>> So if ops is not supported and func returns with 1, then which ops
>>>> application will use?
>>>> If that ops is default_ops.. then How application will distinguish when to
>>>> use default ops or
>>>> param ops?.. as because in both cases func will return with value 1.
>>>>
>>>> The approach in the patch takes care of that condition and func will
>>>> return -ENOTSUP
>>>> if (ops not support || inputted param not matching with default ops)
>>>> otherwise will return
>>>> 0 or 1.
>>>>
>>>> At application side;
>>>> For error case: In case of -ENOTSUP, its upto application to use
>>>> _default_ops or exit.
>>>> For good case: 0 or 1 case, func gaurantee that handle is either best
>>>> handle for pool or pool supports
>>>> that handle.. However in your suggestion if ops not supported case returns
>>>> 1 then application is not
>>>> sure which ops to use.. default_ops Or input ops given to func.
>>>>
>>>> make sense?
>>> My proposition is:
>>>
>>> - what a PMD returns does not depend on used parameter:
>>> - 0: best support
>>> - 1: support
>>> - -ENOTSUP: not supported
>>>
>>> - if a PMD does not implement the _ops_supported() API, assume all pools
>>> are supported (returns 1)
>> If API returns 1 for PMD does not implement _ops_supported() case,
>> then do we really need -ENOTSUP?
> When the PMD explicitly does not support a mempool ops.
>
> Not implementing the API means, like today: "I don't care what
> the mempool ops is, so I a priori support all the ones available,
> without preference".
>
More confusing to me.
If PMD does not implement mempool_ops then
if (_ops_supported() == NULL)
return 1; /// per your proposition.
so I don't see why we need -ENOTSUP error code in API?
