Re: [PATCH] base: arch_topology: Use policy->max to calculate freq_factor

[Lukasz Luba]

On 11/17/21 10:12 AM, Lukasz Luba wrote:
> On 11/15/21 8:10 PM, Thara Gopinath wrote:
> > cpuinfo.max_freq can reflect boost frequency if enabled during boot.  
> > Since
> > we don't consider boost frequencies while calculating cpu capacities, use
> > policy->max to populate the freq_factor during boot up.
> >
> > Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
> > ---
> >   drivers/base/arch_topology.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
> > index 43407665918f..df818b439bc3 100644
> > --- a/drivers/base/arch_topology.c
> > +++ b/drivers/base/arch_topology.c
> > @@ -334,7 +334,7 @@ init_cpu_capacity_callback(struct notifier_block *nb,
> >       cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
> >       for_each_cpu(cpu, policy->related_cpus)
> > -        per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq / 1000;
> > +        per_cpu(freq_factor, cpu) = policy->max / 1000;
> >       if (cpumask_empty(cpus_to_visit)) {
> >           topology_normalize_cpu_scale();
>
> LGTM
>
> Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxxx>

Rafael, Thara, please ignore for a while this review.
We are going to do full investigation of this boost frequency,
capacity, schedutil util-to-freq mapping with cpuinfo.max_freq.
The code pointed by Rafael in that sched_util function
already has issue [1]. We have to figure out the consistent
solution for all platforms.

Regards,
Lukasz

[1] 
https://elixir.bootlin.com/linux/v5.16-rc2/source/kernel/sched/cpufreq_schedutil.c#L152