cpufreq and changing driver

Nate Lawson nate at root.org
Wed Nov 30 18:05:39 GMT 2005

Marco Calviani wrote:
> Hi,
> 2005/11/30, Bruno Ducrot <ducrot at poupinou.org>:
>>You have to load the cpufreq.ko module at boot.
>>Adding that line:
>>cpufreq_load = "YES"
>>to /boot/loader.conf
>>should be OK.
> I have that line in that position, and it seems working. The point is
> that i would like to change the driver and use (AFAIU) a better driver
> for my system (est).
> In particular i have:
> dev.cpu.0.%desc: ACPI CPU
> dev.cpu.0.%driver: cpu
> dev.cpu.0.%location: handle=\_PR_.CPU0
> dev.cpu.0.%pnpinfo: _HID=none _UID=0
> dev.cpu.0.%parent: acpi0
> Maybe i didn't understood well: but what i have to do to use the Intel
> Enhanced SpeedStep driver?

You should send the full output of "sysctl dev.cpu".  There is no 
cpufreq driver (est, acpi_perf, or other) driver running.  Perhaps look 
at your dmesg to see if one is probing/attaching.

If you are using acpi and load cpufreq.ko, you've got all the cpufreq 
drivers in one package.  The right one for your platform will 
automatically probe/attach.

>>powerd need some rework in order to get it working properly.  There
>>is one FreeBSD project on that subject if you are interrested.
> Well, thanks i'm very interested, although i'm not at all experienced
> in kernel programming....
> I'm not inside this issue, but it would not be possible to "emulate"
> the behaviour of the ondemand governor? (sorry if this question makes
> no sense)

I have no idea what you mean by "on-demand governor".  The only 
automated control of cpu speed is either by the BIOS (which we can't 
control) or the TM/TM2 (and that one is heat-based, not load-based).


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