Re: PROBLEM: Cpufreq constantly keeps frequency at maximum on 4.5-rc4

[Arto Jantunen <viiru@iki.fi>]

Viresh Kumar <viresh.kumar@linaro.org> writes:

> On 21-02-16, 22:33, Arto Jantunen wrote:
>> I have tested both available governors, and see the same behavior either
>> way. The kernel I have defaults to performance, I think I'll try
>> building another one which defaults to powersave to see if that changes
>> anything (perhaps both governors actually work but it isn't possible to
>> switch between them at runtime?). The Debian userspace defaults to
>> ondemand, which doesn't exist for intel_pstate.
>
> I took a close look at git log between 4.4 and 4.5-rc1 for intel-pstate and it
> had only three patches:
>
> 157386b6fc14 cpufreq: intel_pstate: Configurable algorithm to get target pstate
> e70eed2b6454 cpufreq: intel_pstate: Account for non C0 time
> 63d1d656a523 cpufreq: intel_pstate: Account for IO wait time
>
> The first one creates special routines based on the CPU model you have, yours is
> 94, i.e. 5e, which means we are going to use: core_params in your case. And so
> you will be using get_target_pstate_use_performance() for .get_target_pstate().
>
> The two later patches doesn't make any changes to the working of core_params()
> and so shouldn't have changed anything for skylake.
>
> Anyway, Please trying reverting the above three patches to see if there is a bug
> somewhere there. So you need to do:
>
> git revert 63d1d656a523
> git revert e70eed2b6454
> git revert 157386b6fc14

Thanks. I tried this, and somewhat surprisingly it doesn't change the
result. I guess we are back to doing a full bisect?

-- 
Arto Jantunen