Re: [Resend][PATCH] cpufreq: conservative: Decrease frequency faster when the timer deferred

Viresh Kumar
2016-11-08T08:32:32Z

On 8 November 2016 at 12:49, Stratos Karafotis <stratosk@semaphore.gr> wrote:
> I think we shouldn't. That's why the patch first decreases the frequency
> by n freq steps (where n the number of deferred periods).
> Then the normal processing takes place.

The problem that I see is that the new algorithm will reduce the
frequency even if we are
on a ramp up phase.

For example consider this case:

- We have a special load running, that runs in bursts. i.e. runs for
some time, lets the CPU idle
then and then again runs.

- To run the load properly, we need to ramp up the frequency

- But the new algorithm can make the frequency stagnant in this case.
i.e. because of the idle
period you may want to decrease the frequency by delta A and then the
regular algorithm may
want to increase it by same delta A.

That's why I was asking to adopt this only in the ramp down path.

--
viresh