Arch Linux

Lyan

Member

Registered: 2014-07-19

Posts: 4

Linux kernel 3.15.6-1 and intel_pstate problem

Hi everyone. I used archlinux a lot, back at the intel core duo age.
Now i've setup everything in my laptop, works great.
(I didn't post in the laptop section because i guess this is only a kernel-driver related problem. Feel free to move the topic)

Now, i have an intel 2430m (i5 2.3 ghz) and my machine runs terribly while on load. It seems that it doesn't disable turbo-boost even on high temperature.
i've installed cpupower (it's disabled in systemd since i don't need the startup script)
i've also installed and enabled thermald from aur (not the git, stable), and it seems that it makes no difference...

I just want to disable completely turbo boost, or disable it at higher temps (shouldn't that be done automatically?)
I tried with this

echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo

But not only it doesn't stick at reboot (which is not a problem for me, easy systemd script), but it doesn't actually work. I keep seeing that the frequency goes up to 2.8 Ghz.
Also, limiting the frequency by the percentage stated in intel_pstate configuration won't work either.

Useful output here:
$ cpupower frequency-info

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 0.97 ms.
  hardware limits: 800 MHz - 2.90 GHz
  available cpufreq governors: performance, powersave
  current policy: frequency should be within 800 MHz and 2.90 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores

(Setting cpupower frequency-set -u clock_freq to 2.3Ghz display the correct policy, but doesn't limit the frequency in real usage)

The driver is intel_pstate, as suggested by the output of cpupower. Also the governor is on powersave (which i read it's the default for intel_pstate, so it should be good).
Any suggestion?
(CPU reaches 90 degrees on load, and turbo boost still kicks in... Is a kernel or a driver issue?)

Last edited by Lyan (2014-07-28 12:31:38)

Asbestbrezel

Member

Registered: 2014-07-27

Posts: 67

Re: Linux kernel 3.15.6-1 and intel_pstate problem

I guess, i've got the same problem. Posted yesterday. https://bbs.archlinux.org/viewtopic.php?id=184849

If you disable intel_pstate in kernel-parameters, it works.

Lyan

Member

Registered: 2014-07-19

Posts: 4

Re: Linux kernel 3.15.6-1 and intel_pstate problem

I guess, i've got the same problem. Posted yesterday. https://bbs.archlinux.org/viewtopic.php?id=184849
If you disable intel_pstate in kernel-parameters, it works.

Disabling intel_pstate get back the old ondemand governor?
Probably intel_pstate are somewhat still bugged.

Lyan

Member

Registered: 2014-07-19

Posts: 4

Re: Linux kernel 3.15.6-1 and intel_pstate problem

I can confirm that when using intel3000 HD (or probably any intel HD series) in graphic intensive app, intel_pstate settings gets ignored somehow...
I'm constantly using VGA external monitor, i'll try to use internal and report back if the issues persist.

Edit: disabling/enabling powersaving features changes nothing, as well as kernel parameters for i915.
Also i tried to enable/disable vsync for application and Dri2 driver, nothing changed. Still CPU frequency gets pumped at 2.9 Ghz.
Settings in the intel_pstate driver don't work, echoing new value sets only the value but doens't change the behaviour.

I tried to revert back to original kernel and not the linux-ck, no difference.

Last edited by Lyan (2014-07-28 14:18:22)