Re: [RFC PATCH v4 2/4] dpll: Add DPLL framework base functions

Jiri Pirko
2022-12-08T08:14:51Z

Wed, Dec 07, 2022 at 05:59:41PM CET, kuba@kernel.org wrote:
>On Wed, 7 Dec 2022 14:10:42 +0100 Jiri Pirko wrote:
>> >> Why do we need this association at all?
>> >
>> >Someone someday may want netns delegation and if we don't have the
>> >support from the start we may break backward compat introducing it.
>>
>> Hmm. Can you imagine a usecase?
>
>Running DPLL control in a namespace / container.
>
>I mean - I generally think netns is overused, but yes, it's what
>containers use, so I think someone may want to develop their
>timer controller SW in as a container?

The netdevices to control are already in the container. Isn't that
enough?

>
>> Link to devlink instance btw might be a problem. In case of mlx5, one
>> dpll instance is going to be created for 2 (or more) PFs. 1 per ConnectX
>> ASIC as there is only 1 clock there. And PF devlinks can come and go,
>> does not make sense to link it to any of them.
>
>If only we stuck to the "one devlink instance per ASIC", huh? :)

Yeah...

>
>> Thinking about it a bit more, DPLL itself has no network notion. The
>> special case is SyncE pin, which is linked to netdevice. Just a small
>> part of dpll device. And the netdevice already has notion of netns.
>> Isn't that enough?
>
>So we can't use devlink or netdev. Hm. So what do we do?
>Make DPLLs only visible in init_net? And require init_net admin?
>And when someone comes asking we add an explicit "move to netns"
>command to DPLL?

Well, as I wrote. The only part needed to be network namespaced are the
netdev related pins. And netdevices have netns support. So my question
again, why is that not enough?