Re: Problem: Possible regression in intel_pstate on 3.12

Viresh Kumar
2013-12-16T09:08:41Z

Adding Dirk in cc..

On 8 December 2013 21:55, Joakim Hernberg <jbh@alchemy.lu> wrote:
> When I'm running KDE on linux 3.12 (archlinux) my intel i7-2600k seems
> to no longer reduce the cpu multiplier and thus runs hotter than under
> linux 3.11. i7z shows the cpu as being close to idle and using C0 to
> C6 states.
>
> On "Linux version 3.12.3-1-ARCH (tobias@T-POWA-LX) (gcc version 4.8.2
> (GCC) ) #1 SMP PREEMPT Wed Dec 4 21:45:42 CET 2013"
>
> Output of # cpupower frequency-list when booted to the command prompt:
>
> 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: 1.60 GHz - 5.90 GHz
> available cpufreq governors: performance, powersave
> current policy: frequency should be within 1.60 GHz and 5.90 GHz.
> The governor "powersave" may decide which speed to use
> within this range.
> current CPU frequency is 1.69 GHz (asserted by call to hardware).
> 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
>
> When booted into KDE and system more or less idle:
>
> 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: 1.60 GHz - 5.90 GHz
> available cpufreq governors: performance, powersave
> current policy: frequency should be within 1.60 GHz and 5.90 GHz.
> The governor "powersave" may decide which speed to use
> within this range.
> current CPU frequency is 4.30 GHz (asserted by call to hardware).
> 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
>
> Output of top while in KDE:
>
> top - 14:21:13 up 9 min, 16 users, load average: 0.48, 0.88, 0.59
> Tasks: 205 total, 1 running, 204 sleeping, 0 stopped, 0 zombie
> %Cpu(s): 1.2 us, 0.4 sy, 0.0 ni, 98.1 id, 0.3 wa, 0.0 hi, 0.0
> si, 0.0 st KiB Mem: 15366248 total, 2435540 used, 12930708 free,
> 71804 buffers KiB Swap: 4193276 total, 0 used, 4193276 free,
> 1135904 cached
>
>
>
> On "Linux version 3.11.6-1-ARCH
> (nobody@var-lib-archbuild-extra-x86_64-thomas) (gcc version 4.8.1
> 20130725 (prerelease) (GCC) ) #1 SMP PREEMPT Fri Oct 18 23:22:36 CEST
> 2013"
>
> Output of cpupower frequency-list while in KDE:
>
> 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: 1.60 GHz - 5.90 GHz
> available cpufreq governors: performance, powersave
> current policy: frequency should be within 1.60 GHz and 5.90 GHz.
> The governor "powersave" may decide which speed to use
> within this range.
> current CPU frequency is 1.94 GHz (asserted by call to hardware).
> 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
>
> I'm attaching the config files of both kernels in case it's simply a
> configuration pebcak.
>
> --
>
> Joakim