[Gflopper]

I recently bought a dv6227cl and am greatly endebted to all the submitters to
this forum for your help in getting linux to run on it. First and formost I
give you a heartfelt thank-you!

There are still some things that I have not been able to get to work, however.
One of the main ones is CPU frequency scaling or throttling.

I am running SimplyMEPIS 6.5.b6_64 and the kernel is reported as
2.6.15-27-desktop64-smp. My dv6227cl has an AMD Turion64x2.

The boot parameters:

root=/dev/sda2 nomce quiet vga=791 resume=/dev/sda3
noapic pci=assign-busses noirqdebug

I noticed the "desktop" word in the kernel name. Is that "desktop" as opposed
to "laptop" or is that "desktop" as opposed to "server"? Anyway, the clock
speed seems to be locked at one frequency regardless of how idle the processor
is. When the ambient temperature is about 23 to 25 degrees C, the temperature
of the notebook (acpi sensor) cycles from 50 to 59 degrees C. It will climb
for about 60 seconds and then fall for about 90 seconds so that it takes about
2.5 minutes to complete a cycle. I can't hear the fan, but I suppose it is
cycling. All of this is with the "KDE System Guard" running, a terminal window
open, and a Konqueror window open, but with no other activity going on on the
notebook. The "process table" of "KDE System Guard" shows itself as taking
about 1.75 "User%" most of the time, and "kded" as taking 0.88 of "User%". And
"System%" and "Nice" are zero almost all the time. In other words, hardly
anything going on. The clock frequencies of both CPU's are 1600Mhz. All this
is with the AC adapter plugged in *or* not! It is the same either on battery
or AC adapter.

I tried in KPowersave to set the "CPU Frequency Policy" to "Dynamic" but it is
still 1600Mhz no matter what.

The temperature and fan would be tolerable if not for the fact they indicate
the battery life will be dismal. Only five minutes after unplugging the AC
adapter (system still just idling), KPowersave indicates a charge of 93% and
estimates 51 minutes remaining. I have not let the battery run down all the
way and timed it for a real test, but it's bound to be rather short without
reducing the clock speed. What I would like, of course, is to have the CPU run
fast when I am really using all those cycles for something, and have the clock
slow when the processor is mearly idling.

Is this what other dv6000 series laptop owners are seeing, or is there a way to
throttle back the clock speed when the system is idle?

[Zelmo]

Check that you have the libcpufreq0 and cpufrequtils packages installed, plus a scaling daemon (powernowd is a good one). Without those, frequency scaling won't work.

[Gflopper]

Originally Posted by Zelmo

Check that you have the libcpufreq0 and cpufrequtils packages installed, plus a scaling daemon (powernowd is a good one). Without those, frequency scaling won't work.

Thank you, Zelmo, for your reply. It helped alittle. I found that I had
libcpufreq0 installed, but did not have cpufrequtils installed. I did install
cpufrequtils. I found I did not have "powernowd" but I do have "powersaved".

After installing the cpufrequtils package, I right-clicked on the KPowersave
icon (it is on the KDE panel and looks like a plug when AC adapter is plugged
in, or a battery unplugged) and changed the "CPU Frequency Policy" from
"Performance" to "Dynamic". By left-clicking on the KPowersave icon, I bring
up the "KPowersave Information Dialog" which shows the "Powersave Daemon:
running" and the frequencies of the two processors still at 1600Mhz. After
rebooting, the CPU policy has changed back to "Performance". I unplug the AC
and the policy changes to "Dynamic", but the processor speeds do not change.
They have always been 1600Mhz. I leave the machine alone until the screen goes
blank (2 minutes) and when I check it again, the speeds are 1600. It says the
"Powersave Daemon" is "running".

Also KDE System Guard shows speeds have been 1600 all along. The temperature has
been cycling from 50 to 60 degrees C with about a 2 minute period. CPU
usr/sys/nice loads all combined have been somewhere below 10%.

Evidently, it's still chewing up energy at a high rate. Is there anything else
I can test or investigate?

[antidrugue]

To enable CPU frequency management, you will need to get the proper modules loaded at startup. Nowadays you don't need anymore a CPU scaling daemon, as this functionality is included directly into the Linux Kernel.

I wrote a tutorial not long ago that sums it up nicely for Debian-based distro (like Mepis or Ubuntu). I suggest you take a look at it :
http://technowizah.com/2007/01/debia...anagement.html

If you have further questions after reading it, just post back.

[Gflopper]

Thank you, antidrugue, for your reply, and for writing that tutorial. I read
the tutorial. As I said before, I am running SimplyMEPIS 64 on an AMD
Turion64x2. It is a "Mobile Technology TL-50". You said a CPU scaling daemon
is not necessary, and that may be, but for some reason the "KPowersave
Information Dialog" in MEPIS reports explicitly "Powersave Daemon: running".

After using KPowersave to set the CPU Frequency Policy to "Dynamic", I issued
the command "cpufreq-info" you mentioned in the tutorial. I got this:

cpufrequtils 0.4: cpufreq-info (C) Dominik Brodowski 2004
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
driver: powernow-k8
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 1.60 GHz
available frequency steps: 1.60 GHz, 800 MHz
available cpufreq governors: userspace, powersave, ondemand, performance
current policy: frequency should be within 800 MHz and 1.60 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 1.60 GHz.
analyzing CPU 1:
driver: powernow-k8
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 1.60 GHz
available frequency steps: 1.60 GHz, 800 MHz
available cpufreq governors: userspace, powersave, ondemand, performance
current policy: frequency should be within 800 MHz and 1.60 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 1.60 GHz.

I also used lsmod to verify that the driver and policy governer modules are
loaded.

It looks like the tutorial says it should and it is consistent with everything
KDE System Guard and KPowersave says, but evidently "ondemand" is deciding
to leave the frequency at it's maximum no matter what. Granted, the frequency
steps are limited to two. But really, it's 1600Mhz and the temperature cycles
from 50 to 60 degrees C with KDE System Guard being the only open window.