Re: [PATCH net-next 03/10] devlink: Serialize access to rate domains

Jiri Pirko
2025-02-25T13:36:12Z

Wed, Feb 19, 2025 at 03:21:30AM +0100, kuba@kernel.org wrote:
>On Fri, 14 Feb 2025 13:54:43 +0100 Jiri Pirko wrote:
>> For the record, I'm still not convinced that introducing this kind of
>> shared inter-devlink lock is good idea. We spent quite a bit of painful
>> times getting rid of global devlink_mutex and making devlink locking
>> scheme nice and simple as it currently is.
>>
>> But at the same time I admit I can't think of any other nicer solution
>> to the problem this patchset is trying to solve.
>>
>> Jakub, any thoughts?
>
>The problem comes from having a devlink instance per function /
>port rather than for the ASIC. Spawn a single instance and the
>problem will go away 🤷️

Yeah, we currently have VF devlink ports created under PF devlink instance.
That is aligned with PCI geometry. If we have a single per-ASIC parent
devlink, this does not change and we still need to configure cross
PF devlink instances.

The only benefit I see is that we don't need rate domain, but
we can use parent devlink instance lock instead. The locking ordering
might be a bit tricky to fix though.

>
>I think we talked about this multiple times, I think at least
>once with Jake, too. Not that I remember all the details now..
>--
>pw-bot: cr