Re: [PATCH net-next 7/9] devlink: allow registering parameters after the instance

[Jacob Keller <jacob.e.keller@intel.com>]

On 1/11/2023 8:45 AM, Jakub Kicinski wrote:
> On Wed, 11 Jan 2023 10:32:13 +0100 Jiri Pirko wrote:
>>>> I'm confused. You want to register objects after instance register?  
>>>
>>> +1, I think it's an anti-pattern.  
>>
>> Could you elaborate a bit please?
> 
> Mixing registering sub-objects before and after the instance is a bit
> of an anti-pattern. Easy to introduce bugs during reload and reset /
> error recovery. I thought that's what you were saying as well.

I was thinking of a case where an object is dynamic and might get added
based on events occurring after the devlink was registered.

But the more I think about it the less that makes sense. What events
would cause a whole subobject to be registerd which we wouldn't already
know about during initialization of devlink?

We do need some dynamic support because situations like "add port" will
add a port and then the ports subresources after the main devlink, but I
think that is already supported well and we'd add the port sub-resources
at the same time as the port.

But thinking more on this, there isn't really another good example since
we'd register things like health reporters, regions, resources, etc all
during initialization. Each of these sub objects may have dynamic
portions (ex: region captures, health events, etc) but the need for the
object should be known about during init time if its supported by the
device driver.