Frequency scaling not working

Kevin J. Cummings cummings at
Wed Nov 21 23:36:18 UTC 2007

Ryan Campbell wrote:
> I still have not been able to get my frequency scaling working, but
> after some looking around I noticed that
> /proc/acpi/processor/CPU0/throttling says:
> # cat /proc/acpi/processor/CPU0/throttling
> <not supported>

Under Fedora 6 (which my laptop is running), I have the CPU Frequency
Scaling Monitor running in the upper menu bar.  Lately (ie, after a
recent kernel update) its been telling me that my processor frequency
scaling is no longer supported.  Odd because it used to be supported.
I was looking into the applets options, it can monitor CPU0 or CPU1.

Then I went and looked at /proc/acpi/processor and found that it
contained 2 entries:  CPU1 and CPU2

> Is this normal?  It seems odd because I also get this:
> # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
> 2001000 2000000 1600000 1200000 800000

and my /sys/devices/system/cpu conatins cpu0 and cpu1 subdirectories,
neither of which has a cpufreq subdirectory.

> Which makes me think that throttling should be working. I am running out
> of ideas though.

I too am at a loss to explain.

> Ryan

Kevin J. Cummings
kjchome at
cummings at
cummings at
Registered Linux User #1232 (

More information about the fedora-list mailing list