Re: [patch v5 11/15] sched: add power/performance balance allow flag

Peter Zijlstra
2013-02-20T13:37:55Z

On Wed, 2013-02-20 at 20:04 +0800, Alex Shi wrote:

> >> @@ -5195,6 +5197,8 @@ static int load_balance(int this_cpu, struct rq
> >> *this_rq,
> >> .idle = idle,
> >> .loop_break = sched_nr_migrate_break,
> >> .cpus = cpus,
> >> + .power_lb = 0,
> >> + .perf_lb = 1,
> >> };
> >>
> >> cpumask_copy(cpus, cpu_active_mask);
> >
> > This construct allows for the possibility of power_lb=1,perf_lb=1, does
> > that make sense? Why not have a single balance_policy enumeration?
>
> (power_lb == 1 && perf_lb == 1) is incorrect and impossible to have.
>
> (power_lb == 0 && perf_lb == 0) is possible and it means there is no any
> balance on this cpu.
>
> So, enumeration is not enough.

Huh.. both 0 doesn't make any sense either. If there's no balancing, we
shouldn't be here to begin with.