Re: [PATCH] sched/cpufreq: Align trace event behavior of fast switching

[Douglas Raillard]

Hi Rafael,

On 8/7/19 9:40 PM, Rafael J. Wysocki wrote:
> On Wed, Aug 7, 2019 at 5:34 PM Douglas RAILLARD
> <douglas.raillard@xxxxxxx> wrote:
> > Fast switching path only emits an event for the CPU of interest, whereas the
> > regular path emits an event for all the CPUs that had their frequency changed,
> > i.e. all the CPUs sharing the same policy.
> >
> > With the current behavior, looking at cpu_frequency event for a given CPU that
> > is using the fast switching path will not give the correct frequency signal.
>
> Do you actually have any systems where that is a problem?  If so, then
> what are they?

That happens on Google Pixel 3 smartphone, which uses this cpufreq driver: drivers/cpufreq/qcom-cpufreq-hw.c.

[1] git clone https://git.linaro.org/people/amit.pundir/linux.git -b blueline-mainline-tracking

Thanks,
Douglas