Re: [PATCH] cpufreq: dt: Set default policy->transition_delay_ns

From: Rafael J. Wysocki
Date: Mon Jun 26 2017 - 20:23:07 EST


On Monday, May 22, 2017 04:57:27 PM Viresh Kumar wrote:
> On 22-05-17, 19:17, Leo Yan wrote:
> > This afternoon Amit pointed me for this patch, should fix as below?
> > Otherwise it seems directly assign the same value from unit 'ns' to
> > 'us' but without any value conversion.
> >
> > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> > index 76877a6..dcc90fc 100644
> > --- a/kernel/sched/cpufreq_schedutil.c
> > +++ b/kernel/sched/cpufreq_schedutil.c
> > @@ -538,7 +538,7 @@ static int sugov_init(struct cpufreq_policy *policy)
> > unsigned int lat;
> >
> > tunables->rate_limit_us = LATENCY_MULTIPLIER;
> > - lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
> > + lat = policy->cpuinfo.transition_latency / NSEC_PER_MSEC;
> > if (lat)
> > tunables->rate_limit_us *= lat;
> > }
>
> I will let Rafael comment in as well. NSEC_PER_USEC is used in the
> earlier governors as well (ondemand/conservative) in exactly the same
> way as schedutil is using.

The reason why it is used by schedutil is because the other governors used it
that way. IOW, doesn't matter. :-)

Thanks,
Rafael