RE: Ask for help on governor

["Doug Smythies" <dsmythies@telus.net>]

Hi,

On 2017.12.14 Stratos Karafotis wrote:

> I'm not sure I understood what the problem is (maybe because I can't see
> the description of the issue in the quotes).

For my part of it, the problem is that the default sample_period for
the intel_cpufreq scaling driver (i.e. intel_pstate in passive mode)
is 500 uSec. Everything, as far as I can determine, becomes busted if
the sampling period is less than a jiffy.

By the way, the default sampling period for the acpi_cpufreq driver seems to be
10 milliseconds, and everything is fine. I do not know why the defaults for
the intel_cpufreq driver are so short, and suggest that they shouldn't be,
in which case your commit might be O.K.

>
> Commit 00bfe05889e91b5112893b001e4a47b0a0f8bdd7 affects only conservative
> governor.
> Do you have the same issue with ondemand too?

Yes, this entire thread has been about the conservative governor.

That was the first time Andy mentioned issues with on demand, but
I do see it misbehave with the intel_cpufreq default sample period
(a.k.a sampling_rate) of 500uSec. See another e-mail I send in a moment.

... Doug