Re: [PATCH] cpufreq,cppc: fix issue when hotplugging out policy->cpu

From: Ionela Voinescu
Date: Tue Sep 22 2020 - 12:25:44 EST


Sorry for the delay, I just got back from holiday as well.

On Monday 07 Sep 2020 at 11:41:54 (+0530), Viresh Kumar wrote:
> On 04-09-20, 10:43, Ionela Voinescu wrote:
> > Do you know why it was designed this way in the first place?
> No.
> > I assumed it was designed like this (per-cpu cppc_cpudata structures) to
> > allow for the future addition of support for the HW_ALL CPPC coordination
> > type. In that case you can still have PSD (dependency) domains but the
> > desired performance controls would be per-cpu, with the coordination
> > done in hardware/firmware. So, in the HW_ALL case you'd end up having
> > different performance controls even for CPUs in the same policy.
> > Currently the CPPC driver only supports SW_ANY which is the traditional
> > cpufreq approach.
> Then the person who would add that feature will take care of fixing the issues
> then. We should make sure we handle the current use-case optimally. And a
> per-cpu thing isn't working well for that.

Okay, I'll follow your lead and remove the per-cpu structures.


> --
> viresh