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#1 2013-03-11 12:33:33

wudu
Member
Registered: 2010-03-08
Posts: 80

cpupower - can set performance and powersave governors only

Hi,
I got a HP compaq nx6110 laptop (I know, it's old and slow but it fits my needs for a laptop and it was free smile ). To increase the time on battery I installed laptop-mode-tools and cpupower. The laptop-mode-tools does what it should but cpupower doesn't set the governors correct.

After modprobing p4_clockmod I can make use of cpupower to get infos:

[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  driver: p4-clockmod
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.00 ms.
  hardware limits: 175 MHz - 1.40 GHz
  available frequency steps: 175 MHz, 350 MHz, 525 MHz, 700 MHz, 875 MHz, 1.05 GHz, 1.23 GHz, 1.40 GHz
  available cpufreq governors: ondemand, performance
  current policy: frequency should be within 175 MHz and 1.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.40 GHz (asserted by call to hardware).
  boost state support:
    Supported: no
    Active: no

But I can't set the governor to ondemand:

[root@Laptop wudu]# cpupower frequency-set -g ondemand
Setting cpu: 0
[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  driver: p4-clockmod
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.00 ms.
  hardware limits: 175 MHz - 1.40 GHz
  available frequency steps: 175 MHz, 350 MHz, 525 MHz, 700 MHz, 875 MHz, 1.05 GHz, 1.23 GHz, 1.40 GHz
  available cpufreq governors: ondemand, performance
  current policy: frequency should be within 175 MHz and 1.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.40 GHz (asserted by call to hardware).
  boost state support:
    Supported: no
    Active: no

After modprobing cpufreq_conservative and cpufreq_powersave cpupower tells me that these governors are available now:

[root@Laptop wudu]# modprobe cpufreq_conservative
[root@Laptop wudu]# modprobe cpufreq_powersave   
[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  driver: p4-clockmod
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.00 ms.
  hardware limits: 175 MHz - 1.40 GHz
  available frequency steps: 175 MHz, 350 MHz, 525 MHz, 700 MHz, 875 MHz, 1.05 GHz, 1.23 GHz, 1.40 GHz
  available cpufreq governors: powersave, conservative, ondemand, performance
  current policy: frequency should be within 175 MHz and 1.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.40 GHz (asserted by call to hardware).
  boost state support:
    Supported: no
    Active: no

So I'm trying them:

[root@Laptop wudu]# cpupower frequency-set -g conservative
Setting cpu: 0
[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  driver: p4-clockmod
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.00 ms.
  hardware limits: 175 MHz - 1.40 GHz
  available frequency steps: 175 MHz, 350 MHz, 525 MHz, 700 MHz, 875 MHz, 1.05 GHz, 1.23 GHz, 1.40 GHz
  available cpufreq governors: powersave, conservative, ondemand, performance
  current policy: frequency should be within 175 MHz and 1.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.40 GHz (asserted by call to hardware).
  boost state support:
    Supported: no
    Active: no
[root@Laptop wudu]# cpupower frequency-set -g powersave   
Setting cpu: 0
[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  driver: p4-clockmod
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.00 ms.
  hardware limits: 175 MHz - 1.40 GHz
  available frequency steps: 175 MHz, 350 MHz, 525 MHz, 700 MHz, 875 MHz, 1.05 GHz, 1.23 GHz, 1.40 GHz
  available cpufreq governors: powersave, conservative, ondemand, performance
  current policy: frequency should be within 175 MHz and 1.40 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 175 MHz (asserted by call to hardware).
  boost state support:
    Supported: no
    Active: no

As you can see cpupower can just set performance and powersave. I want to use ondemand when on battery because the laptop is already slow in performance mode but nearly unusable when in powersave mode (175MHz).

BTW I can set to all speeds listed manually. Showing you with 875MHz as example:

[root@Laptop wudu]# cpupower frequency-set -u 875000     
Setting cpu: 0
[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  driver: p4-clockmod
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.00 ms.
  hardware limits: 175 MHz - 1.40 GHz
  available frequency steps: 175 MHz, 350 MHz, 525 MHz, 700 MHz, 875 MHz, 1.05 GHz, 1.23 GHz, 1.40 GHz
  available cpufreq governors: powersave, conservative, ondemand, performance
  current policy: frequency should be within 175 MHz and 875 MHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 875 MHz (asserted by call to hardware).
  boost state support:
    Supported: no
    Active: no

Hope some one has an idea...
Thanks in advance.

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#2 2013-03-11 12:41:01

Gusar
Member
Registered: 2009-08-25
Posts: 3,605

Re: cpupower - can set performance and powersave governors only

p4_clockmod is, like it's name says, for P4 processors. It does clock modulation, not frequency scaling. You have a Pentium M in there, so you should use acpi_cpufreq. Which should get automatically loaded nowadays. Though if it doesn't, load it manually. With it loaded, ondemand should then be available. Latest kernels have it as default even (because using anything else makes no sense).

Though if you have an actual P4 in there (the info google gives is kinda confusing)... Well then like I said, p4_clockmod does clock modulation, not frequency scaling. Having it at anything other than performance makes no sense. The point of clock modulation is thermal management, not powersaving. The P4 doesn't have any powersaving.

Last edited by Gusar (2013-03-11 12:45:10)

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#3 2013-03-11 12:54:58

wudu
Member
Registered: 2010-03-08
Posts: 80

Re: cpupower - can set performance and powersave governors only

It's an Intel Celeron CPU and according to https://wiki.archlinux.org/index.php/CP … ncy_driver p4_clockmod is correct.

Trying to modprobe acpi-cpufreq gives me that:

[root@Laptop wudu]# modprobe acpi-cpufreq
modprobe: ERROR: could not insert 'acpi_cpufreq': No such device

And p4_clockmod puts speedstep-lib in as well:

[root@Laptop wudu]# lsmod | grep p4
p4_clockmod             3201  0 
speedstep_lib           5136  1 p4_clockmod

With speedstep-lib loaded without p4_clockmod I can't use cpupower:

[root@Laptop wudu]# rmmod p4_clockmod
[root@Laptop wudu]# lsmod | grep p4
[root@Laptop wudu]# lsmod | grep speed
speedstep_lib           5136  0 
[root@Laptop wudu]# cpupower frequency-info
analyzing CPU 0:
  no or unknown cpufreq driver is active on this CPU
  boost state support:
    Supported: no
    Active: no

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#4 2013-03-11 13:07:35

wudu
Member
Registered: 2010-03-08
Posts: 80

Re: cpupower - can set performance and powersave governors only

Sorry, read before your edit. Thanks for that info.
You say it's used for thermal management. But how can it decrease temperature without saving power?

Last edited by wudu (2013-03-11 13:10:09)

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#5 2013-06-07 02:00:04

nunobaba
Member
From: paris, france
Registered: 2009-03-11
Posts: 16

Re: cpupower - can set performance and powersave governors only

Interesting. My situation is quite the same, with only cpufreq governors powersave and performance loaded, while the others could not be loaded. I'd be much interested to a hint to adjust the configuration to make this work.

Here's the content of /etc/modules-load.d/acpi-cpufreq.conf

acpi-cpufreq
cpufreq_ondemand
cpufreq_conservative
cpufreq_powersave

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#6 2013-06-07 08:21:52

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

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#7 2013-06-07 09:05:44

nunobaba
Member
From: paris, france
Registered: 2009-03-11
Posts: 16

Re: cpupower - can set performance and powersave governors only

Many thanks, Karol, for the links. I was tweaking the intel_pstate parameter last night while missing this interesting conversation. And no change to the situation insofar, which has these aspects:

- All cpufreq_ondemand, cpufreq_conservative and cpufreq_userspace simply don't get loaded. Does the intel_pstate imply all scaling governors except the powersave and performance could not be loaded?

- Modprobing any of these governors manually doesn't include them either.

- The systemctl-modules-load.service is also down, failing to load at boot.

Could there be something I keep missing?

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