Re: [PATCH 1/4] PM / EM: and devices to Energy Model

On Monday 20 Jan 2020 at 15:53:35 (+0100), Dietmar Eggemann wrote:

Would be really nice if this wouldn't be required. We should really aim for 1 framework == 1 set of interfaces.

What happens if someone calls em_get_pd() on a CPU EM?

E.g:

static struct perf_domain *pd_init(int cpu) {

•   struct em_perf_domain *obj = em_cpu_get(cpu);
  

•   struct device *dev = get_cpu_device(cpu);
  

•   struct em_perf_domain *obj = em_pd_get(dev);
    struct perf_domain *pd;
  
  

Two versions of one functionality will confuse API user from the beginning ...

Agreed, this looks a bit confusing. It should be trivial to make em_dev_get() (or whatever we end up calling it) work for CPUs too, though. And we could always have a em_cpu_get(int cpu) API that is a basically a wrapper around em_dev_get() for convenience.

Thanks, Quentin