Re: [PATCH V3 3/3] arm64: topology: Make AMUs work with modular cpufreq drivers

From: Ionela Voinescu
Date: Tue Dec 15 2020 - 07:00:38 EST


Hi,

On Tuesday 15 Dec 2020 at 11:04:16 (+0530), Viresh Kumar wrote:
> The AMU counters won't get used today if the cpufreq driver is built as
> a module as the amu core requires everything to be ready by late init.
>
> Fix that properly by registering for cpufreq policy notifier. Note that
> the amu core don't have any cpufreq dependency after the first time
> CPUFREQ_CREATE_POLICY notifier is called for all the CPUs. And so we
> don't need to do anything on the CPUFREQ_REMOVE_POLICY notifier. And for
> the same reason we check if the CPUs are already parsed in the beginning
> of amu_fie_setup() and skip if that is true. Alternatively we can shoot
> a work from there to unregister the notifier instead, but that seemed
> too much instead of this simple check.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> ---
> V3:
> - This is a new patch.
>
> Ionela,
>
> I don't have a way to test the AMU stuff, will it be possible for you to
> give it a try ?
>

I'll review this new patch and then I'll give the full set a try.

Thanks for the interest in improving this,
Ionela.