Re: [intel-pstate driver regression] processor frequency very high even if in idle

From: JÃrg Otte
Date: Tue Mar 29 2016 - 13:32:33 EST


2016-03-29 19:24 GMT+02:00 JÃrg Otte <jrg.otte@xxxxxxxxx>:
> in v4.5 and earlier intel-pstate downscaled idle processors (load
> 0.1-0.2%) to minumum frequency, in my case 800MHz.
>
> Now in v4.6-rc1 the characteristic has dramatically changed. If in
> idle the processor frequency is more or less a few MHz around 2500Mhz.
> This is the maximum non turbo frequency.
>
> No difference between powersafe or performance governor.
>
> I currently use acpi_cpufreq which works as usual.
>
> Processor:
> Intel(R) Core(TM) i5-4200M CPU @ 2.50GHz (family: 0x6, model: 0x3c,
> stepping: 0x3)
>
> Last known good kernel is: 4.5.0-01127-g9256d5a
> First known bad kernel is: 4.5.0-02535-g09fd671
>
> There is
> commit 277edba Merge tag 'pm+acpi-4.6-rc1-1' of
> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
> in between, which brought a few changes in intel_pstate.
>
> thanks, JÃrg