laptop & cpu

[Bas van Gils]

On Wed, Oct 12, 2005 at 07:48:13PM +0200, Bas van Gils wrote:
> 
> A while ago I migrated from another distro (SourceMage) to ubuntu. Pretty
> happy with it. While I was still running SMGL, the CPU of my laptop would slow
> down as soon as the powercord was pulled from the laptop (i.e., when I'm on
> the road). A friend helped me set it up a while ago but I completely forgot
> what was involved. Is this also possible on ubuntu? Any pointers?

Hi again,

I spent a bit more time on this and did a lil' more research. First some info
about my box. The relevant bits from "/proc/cpuinfo" are:

  vendor_id : GenuineIntel
  model name  : Intel(R) Pentium(R) 4 CPU 2.50GHz
  flags   : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36
  clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid

The flags suggest that acpi should work. Well, it does (for example: closing
the lid will push X into screenlock). From "/var/log/kern.log" I learned that:

  kern.log.0:Oct  4 16:11:46 localhost kernel: Access to /proc/cpufreq is
  deprecated and will be removed from (new) 2.6. kernels soon after 2005-01-01

After a bit of googling I found [1] which suggested that I should use

  /sys/devices/system/cpu/cpu0/cpufreq/

However, that directory doesn't exist. I tried to load the modules that are
listed on [1]. All went fine except for acpi-cpufreq. Trying to load that one
results in:

  # sudo modprobe acpi-cpufreq
  FATAL: Error inserting acpi_cpufreq (/lib/modules/2.6.12-9-386/kernel/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.ko): No such device

which seems to be consistent with the missing directory. A bit more googling
lead to a very nice post on ubuntu forum which in turn lead to [2]. This page
has more interesting info about getting cpufreq to work. The suggestion there
was to look at the errors in dmesg but `dmesg | grep -i acpi | grep -i error`
comes up empty in my case.

At this point I'm lost ;-) Any help is appreciated. Thanks,


  Bas





[1] http://www.thinkwiki.org/wiki/How_to_make_use_of_Dynamic_Frequency_Scaling#Using_the_Sys_Interface
[2] http://pages.cpsc.ucalgary.ca/~weckerl/ferrari_ubuntu_64.html

-- 
<Bas.vanGils at cs.ru.nl> - GPG Key ID: 2768A493  -  http://www.cs.ru.nl/~basvg
Radboud University Nijmegen Institute for Computing and Information Sciences