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

From: Viresh Kumar
Date: Mon Sep 07 2020 - 02:12:10 EST


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.

--
viresh