cpufrequtils, when does it increase the CPU speed?

Yes · 2008-05-05 21:13:04

I just installed cpufreqtils and set it up, and it lowered my CPU frequency from 2.33 GHz to 2.00. I wanted to see if it would bring it back up, but when I tried compiling something it stayed at 2.00, even though the CPU usage was almost 100 %. Does this mean I configured something wrong, or does it just take a few minutes to come back up? It was only Irssi, so it wasn't at 100 % for more than 30 seconds.

Thanks!

Raccoon1400 · 2008-05-05 21:57:41

Is the maximum frequency set right?
/etc/conf.d/cpufreq
That's my best guess.
Adjust the min value too. My core duo has two 1.6GHz cores, and they spend most of their time at 800MHz.

phrakture · 2008-05-05 22:00:22

It adjusts based on the governor you choose. The cpufreq governing is described here: http://www.mjmwired.net/kernel/Document … ernors.txt (this is a random find via google, there may be better docs elsewhere)

Raccoon1400 · 2008-05-05 22:11:06

Thanks for the link. I was wondering what the difference was.

Is your governor set to powersave?

Yes · 2008-05-05 22:21:02

My governor is set to ondemand, and if I understand correctly that means it should increase when it needs to.

The min/max values are 2.00 Ghz and 2.33 GHz, which is what cpufreq-info says the hardware limits are.

Raccoon1400 · 2008-05-05 22:39:38

Try setting it to performance and see if it goes up to 2.33 then
Or open the largest app you can think of. A virtual machine brings my cpu scaling to max for almost the entire time the guest OS is running.

low · 2008-05-05 22:50:56

I have the clock values commented out in /etc/conf.d/cpufreq, the kernel detects them and sets the limits automatically. Also, dunno if it is necessary, but I have 'cpufreq' in rc.conf.

Yes · 2008-05-06 19:40:29

Commenting out the lines doesn't do anything. I have cpufreq in my rc.conf.

I tried setting it to performance with `cpufreq-set -g performance`, but cpufreq-info still reported the speed as being 2.00 GHz.

Raccoon1400 · 2008-05-06 22:09:23

acpi-cpufreq cpufreq_ondemand cpufreq_powersave

did you add these modules to the modules section in rc.conf?

Yes · 2008-05-06 22:33:25

I have acpi-cpufreq and cpufreq_ondemand, but not cpufreq_powersave. Do I need that too? I modprobed it before I tried `cpufreq-set -g performance`.

Raccoon1400 · 2008-05-06 22:38:43

you need powersave if you want to use the powersave governor.

Yes · 2008-05-06 23:14:37

Ok, but if I'm using ondemand I don't need powersave in rc.conf, right?

peart · 2008-05-06 23:18:09

Yes wrote:

Ok, but if I'm using ondemand I don't need powersave in rc.conf, right?

Right. I use ondemand and don't have powersave in rc.conf. Everything woks just fine.

Yes · 2008-05-06 23:31:37

peart wrote:

Right. I use ondemand and don't have powersave in rc.conf. Everything woks just fine.

Would you mind sharing your /etc/conf.d/cpufreq file, as well as what you have in your /etc/rc.conf and your processor?

I think it might have something to do with the fact that I have a dual core processor. I added `echo "ondemand" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor` and `echo "ondemand" > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor` to /etc/rc.local like the Wiki says, but it still seems like I'm doing something wrong.

peart · 2008-05-06 23:55:56

Yes,

I have an Intel Core 2 Duo T7200. My cpufreq setup is pretty straight-forward. Here's the interesting parts of rc.conf:

MODULES=(acpi_cpufreq)
DAEMONS=(syslog-ng @iptables @acpid @cpufreq @crond @alsa @hal @fam @slim net-profiles !nfslock !cups)

Last but not least, a very simple /etc/conf.d/cpufreq:

#configuration for cpufreq control

# valid governors:
#  ondemand, performance, powersave,
#  conservative, userspace
governor="ondemand"

# valid suffixes: Hz, kHz (default), MHz, GHz, THz
min_freq="1GHz"
max_freq="2GHz"

I just started a kernel compilation, and ran cpufreq-info many times, and the speed of both cores did jump around between 1GHz and 2GHz. So everything works.

There is one thing worth mentioning, in case it makes a difference. I used a stripped down minimalist kernel (which explains why my MODULES array is so tiny). I don't think it would make a difference tho. I've seen my cpufreq stuff work with Arch's kernel26.

Yes · 2008-05-07 00:46:45

Did you do anything special for your Core 2 Duo?

My config files all look the same, but I started compiling the kernel and it still didn't go back up to 2.33 GHz.

peart · 2008-05-07 01:26:47

No Yes I didn't ?!?

Everything I did is listed in my post above, and just works like that. I'm really not sure why your processors don't go up to full speed. I only have two suggestions:

1) Try loading module cpufreq_stats then rerunning a kernel compilation. Afterwards, check the file /sys/devices/system/cpu/cpu<X>/cpufreq/stats. It'll show you how much time the CPU spent at each frequency stepping. Maybe it does go up to 2.33GHz, but for very brief periods, so you just don't see it.

2) Have you checked for clues in /var/log/everything.log? Perhaps even /proc/cpuinfo? Maybe there's an error or warning that'll tell you what's going on.

Yes · 2008-05-07 19:53:56

/sys/devices/system/cpu/cpu<X>/cpufreq/stats/time_in_state says that both cores spend 0 time at 2.33 GHz. There's nothing in /proc/cpuinfo, and the only possible problems in /var/log/everything.log are these exceptions that apparently happened on bootup:

May  7 14:42:10 arch ACPI: Processor [CPU0] (supports 8 throttling states)
May  7 14:42:10 arch ACPI: SSDT 7FEE8300, 0087 (r1  PmRef  Cpu1Ist     3000 INTL 20040311)
May  7 14:42:10 arch ACPI: Processor [CPU1] (supports 8 throttling states)
May  7 14:42:10 arch ACPI Exception (processor_core-0816): AE_NOT_FOUND, Processor Device is not present [20070126]
May  7 14:42:10 arch ACPI Exception (processor_core-0816): AE_NOT_FOUND, Processor Device is not present [20070126]

Arch Linux

#1 2008-05-05 21:13:04

cpufrequtils, when does it increase the CPU speed?

#2 2008-05-05 21:57:41

Re: cpufrequtils, when does it increase the CPU speed?

#3 2008-05-05 22:00:22

Re: cpufrequtils, when does it increase the CPU speed?

#4 2008-05-05 22:11:06

Re: cpufrequtils, when does it increase the CPU speed?

#5 2008-05-05 22:21:02

Re: cpufrequtils, when does it increase the CPU speed?

#6 2008-05-05 22:39:38

Re: cpufrequtils, when does it increase the CPU speed?

#7 2008-05-05 22:50:56

Re: cpufrequtils, when does it increase the CPU speed?

#8 2008-05-06 19:40:29

Re: cpufrequtils, when does it increase the CPU speed?

#9 2008-05-06 22:09:23

Re: cpufrequtils, when does it increase the CPU speed?

#10 2008-05-06 22:33:25

Re: cpufrequtils, when does it increase the CPU speed?

#11 2008-05-06 22:38:43

Re: cpufrequtils, when does it increase the CPU speed?

#12 2008-05-06 23:14:37

Re: cpufrequtils, when does it increase the CPU speed?

#13 2008-05-06 23:18:09

Re: cpufrequtils, when does it increase the CPU speed?

#14 2008-05-06 23:31:37

Re: cpufrequtils, when does it increase the CPU speed?

#15 2008-05-06 23:55:56

Re: cpufrequtils, when does it increase the CPU speed?

#16 2008-05-07 00:46:45

Re: cpufrequtils, when does it increase the CPU speed?

#17 2008-05-07 01:26:47

Re: cpufrequtils, when does it increase the CPU speed?

#18 2008-05-07 19:53:56

Re: cpufrequtils, when does it increase the CPU speed?

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