Re: [PATCH iwl-next v4 0/5] iavf: Add devlink and devlink rate support'

Zhang, Xuejun
2023-08-28T22:46:15Z

On 8/24/2023 12:04 AM, Jiri Pirko wrote:
> Wed, Aug 23, 2023 at 09:13:34PM CEST, xuejun.zhang@intel.com wrote:
>> On 8/22/2023 8:34 AM, Jiri Pirko wrote:
>>> Tue, Aug 22, 2023 at 05:12:55PM CEST,kuba@kernel.org wrote:
>>>> On Tue, 22 Aug 2023 08:12:28 +0200 Jiri Pirko wrote:
>>>>> NACK! Port function is there to configure the VF/SF from the eswitch
>>>>> side. Yet you use it for the configureation of the actual VF, which is
>>>>> clear misuse. Please don't
>>>> Stating where they are supposed to configure the rate would be helpful.
>>> TC?
>> Our implementation is an extension to this commit 42c2eb6b1f43 ice: Implement
>> devlink-rate API).
>>
>> We are setting the Tx max & share rates of individual queues in a VF using
>> the devlink rate API.
>>
>> Here we are using DEVLINK_PORT_FLAVOUR_VIRTUAL as the attribute for the port
>> to distinguish it from being eswitch.
> I understand, that is a wrong object. So again, you should use
> "function" subobject of devlink port to configure "the other side of the
> wire", that means the function related to a eswitch port. Here, you are
> doing it for the VF directly, which is wrong. If you need some rate
> limiting to be configured on an actual VF, use what you use for any
> other nic. Offload TC.
Thanks for detailed explanation and suggestions. Sorry for late reply as
it took a bit longer to understand options.

As sysfs has similar rate configuration on per queue basis with
tx_maxrate, is it a viable option for our use case (i.e allow user to
configure tx rate for each allocated queue in a VF).

Pls aslo see If adding tx_minrate to sysfs tx queue entry is feasible on
the current framework.