Arch Linux

mocambo

Member

Registered: 2017-09-24

Posts: 27

CPU works constantly on low state

Hello !

Discovered that Pentium M 2.25GHz works constantly on the low 800Mhz level.

XFCE cpu frequency monitor says:

"Your system does not support cpufreq.
The plugin only shows the current cpu frequency."

/sys/devices/system/cpu/cpu*/cpufreq catalog is empty.

In the pentium4, i686 and i486 kernel config files i see CONFIG_X86_INTEL_PSTATE=y. https://wiki.archlinux.org/title/CPU_frequency_scaling states that Intel_pstate implements a scaling driver with an internal governor for Intel Core (Sandy Bridge and newer) processors. Is that right that cpufreq part of 32 bit linux kernel is optimized for i3/i5/i7 processors ?

If I remember correctly, with Manjaro kernels I did'nt had such a problems. Unfortunately I cant find any configs used for compiling 32-bit Manjaro kernels.

Tried with linux and linux-zen with the same result.

Any ideas ?

# dmesg | grep intel_pstate
[    1.998139] intel_pstate: CPU model not supported

# modprobe acpi-cpufreq
modprobe: ERROR: could not insert 'acpi_cpufreq': No such device

# cpupower frequency-info
analyzing CPU 0:
  no or unknown cpufreq driver is active on this CPU
  CPUs which run at the same hardware frequency: Not Available
  CPUs which need to have their frequency coordinated by software: Not Available
  maximum transition latency:  Cannot determine or is not supported.
Not Available
  available cpufreq governors: Not Available
  Unable to determine current policy
  current CPU frequency: Unable to call hardware
  current CPU frequency:  Unable to call to kernel
  boost state support:
    Supported: no
    Active: no

# cpufreq-bench
loading defaults
parsing: sleep -> 50000
parsing: load -> 50000
parsing: cpu -> 0
parsing: priority -> LOW

parsing: output -> /var/log/cpufreq-bench
logfilename: /var/log/cpufreq-bench/benchmark_archlinux_5.12.15-zen1-1.0-zen-zen_1630944287.log
Logfile: /var/log/cpufreq-bench/benchmark_archlinux_5.12.15-zen1-1.0-zen-zen_1630944287.log
parsing: sleep_step -> 50000
parsing: load_step -> 50000
parsing: cycles -> 20
parsing: rounds -> 40
parsing: verbose -> 0
parsing: governor -> ondemand
approx. test duration: 57m
set affinity to cpu #0
set scheduler priority to 0
set performance as cpufreq governor
cpufreq_modify_policy_governor: No such file or directory
error: unable to set performance governor

Last edited by mocambo (2021-09-10 02:01:43)

levi

Moderator

From: Yorkshire, UK

Registered: 2018-06-16

Posts: 1,197

Re: CPU works constantly on low state

I also get intel_pstate not supported in my dmesg, but on this pentium4 capable CPU is it does switch between about four different frequencies when loaded and thermally limited.  I guess it's not using intel_pstate for that.

---

Architecture: pentium4, Testing repos: Yes, Hardware: EeePC 901+2GB RAM+OS half on the SD card.

abaumann

Administrator

From: Zurich

Registered: 2019-11-14

Posts: 1,032

Website

Re: CPU works constantly on low state

Just a feeling of mine, but intel_pstate seems a little bit too for a Pentium M. I would try other methods like 'speedstep', 'acpi' or 'p4-clockmod'.
I also had isues with cpupower with certain machines (even 64-bit ones, so also 'cpufrequtils' might be an option.