Re: [PATCH v3 4/7] thermal/drivers/tegra: Add driver for Tegra30 thermal sensor

Dmitry Osipenko
2021-06-16T08:39:57Z

16.06.2021 11:30, Vincent Guittot пишет:
> On Wed, 16 Jun 2021 at 10:03, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>>
>> +Vincent.
>>
>> On 15-06-21, 22:32, Dmitry Osipenko wrote:
>>> IIUC, the cpufreq already should be prepared for the case where firmware
>>> may override frequency. Viresh, could you please clarify what are the
>>> possible implications of the frequency overriding?
>>
>> The only implication is software would think hardware is running at
>> some other frequency, while it is not. Not sure if something may break
>> as a result of this.
>>
>> The scheduler's view of CPUs will not be same though, i.e. scheduler
>> will see capacity as X, while in reality it has changed to Y.
>
> thermal_pressure is used by scheduler to balance the load between CPUs
> according to the actual max frequency. If the thermal pressure doesn't
> reflect reality, scheduler will end up enqueuing too many tasks on a
> throttle CPU.

What if all CPUs are throttled equally and running on the same
frequency, will throttling have any effect on the scheduler decisions?