Re: [RFC PATCH v3 05/10] sched/topology: Reference the Energy Model of CPUs when available

[Peter Zijlstra]

On Tue, Jun 19, 2018 at 06:13:17PM +0100, Quentin Perret wrote:
> I agree having one list per root_domain should be better. I'll change that
> in v4. But I also think the idea of a global static_key is broken then.

Static keys are global per definition, there is only a single copy of
the code.

You have to enable if there is a root domain with more than 1
freq-domain.

> We need a per root_domain thing as well. The SD_ASYM_CPUCAPACITY flag
> might be set on one hierarchy and not the other for ex. Not sure if
> attaching a static_key to each root_domain really makes sense though ...
> 
> Would replacing the static_key by a flag attached to the root_domain be
> reasonable ? 

Keep the static key as is, enable if any root domain needs it.

> > (and an empty list if there is but one entry on).
> 
> Sorry but I didn't understand that ...

If you have only a single freq-domain, there is nothing to do, right?