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

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

On 10/27/2019 9:04 AM, Matan Azrad wrote:
> Hi All
> 
> From: Andrew Rybchenko
>> On 10/18/19 7:35 PM, Ferruh Yigit wrote:
>>> 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@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@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?
>>
>> I don't mind to accept it in 19.11 modulo better description of what is LRO
>> session length/size.
> 
> 
> Thanks,
> 
> We can create the patch for ethdev for 19.11-RC2.
> 
> Also PMD implementation to use it for RC2.
> 
> Is it OK? (We need to break ABI as described in the deprecation notice)
> 

OK from me to have ethdev update and PMD implementation for rc2.