[dpdk-dev] [RFC] ethdev: add new fields for max LRO session size

[Ferruh Yigit]

On 10/2/2019 2:58 PM, Thomas Monjalon wrote:
> 24/09/2019 14:03, Matan Azrad:
>> From: Ferruh Yigit
>>> On 9/15/2019 8:48 AM, Matan Azrad wrote:
>>>> Hi Ferruh
>>>>
>>>> From: Ferruh Yigit <ferruh.yigit at intel.com>
>>>>> On 8/29/2019 8:47 AM, Matan Azrad wrote:
>>>>>> It may be needed by the user to limit the LRO session packet size.
>>>>>> In order to allow the above limitation, add new Rx configuration for
>>>>>> the maximum LRO session size.
>>>>>>
>>>>>> In addition, Add a new capability to expose the maximum LRO session
>>>>>> size supported by the port.
>>>>>>
>>>>>> Signed-off-by: Matan Azrad <matan at mellanox.com>
>>>>>
>>>>> Hi Matan,
>>>>>
>>>>> Is there any existing user of this new field?
>>>>
>>>> All the LRO users need it due to the next reasons:
>>>>
>>>> 1. If scatter is enabled - The dpdk user can limit the LRO session size created
>>> by the HW by this field, if no field like that - there is no way to limit it.
>>>> 2. No scatter - the dpdk user may want to limit the LRO packet size in order
>>> to save enough tail-room in the mbuf for its own usage.
>>>> 3. The limitation of max_rx_pkt_len is not enough - doesn't make sense to
>>> limit LRO traffic as single packet.
>>>>
>>>
>>> So should there be more complement patches to this RFC? To update the
>>> users of the field with the new field.
>>
>>
>> We already exposed it as ABI breakage in the last deprecation notice.
>> We probably cannot complete it for 19.11 version, hopefully for 20.02 it will be completed.
> 
> We won't break the ABI in 20.02.
> What should be done in 19.11?
> 

The ask was to add code that uses new added fields, this patch only adds new
field to two public ethdev struct.

@Thomas, @Andrew, if this patch doesn't goes it on this release it will have to
wait a year. I would like to see the implementation but it is not there, what is
your comment?