Bug 240485

Summary: [Powerdevil | KDE 4.4.80] Powerdevil doesn't seem to be able to handle Cpufreq for powersaving
Product: [Unmaintained] solid Reporter: Panos <panosfilip>
Component: powermanagement-daemonAssignee: Dario Freddi <drf>
Status: RESOLVED NOT A BUG    
Severity: normal CC: julroy67, tiposchi, virgolus
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Unlisted Binaries   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Panos 2010-06-02 18:07:01 UTC 
Version:           unspecified (using Devel) 
OS:                Linux

Archlinux x86_64
KDE 4.5 beta1 (4.4.80)
Linux kernel 2.6.34

After upgrading, I found out that I couldn't handle cpufreq through Powerdevil. Even though "Enable system power saving" is enabled, CPU's power throttle (Intel Core i5 750) is being used "ondemand" (I guess by BIOS or the kernel, because cpufreq reports that it is on "performance" mode).

Is it possible that I could handle Cpufreq through KDE 4.5 or is that disabled ? I would like to have my CPU under powersaving scheme most of the time.



Reproducible: Always

Steps to Reproduce:
Steps to reproduce in order to make sure that Powerdevil should enable powersaving.

1. Upgrade to KDE 4.5 beta1
2. Navigate to Systemsettings > Power Management
3. In Profile Management, in "When AC adaptor is plugged in" (or the battery option) choose "Powersave"
4. In "Edit Profiles" > "Powersave", tick the "Enable System power saving", and then press apply.

Actual Results:  
Even though that should enable system powersaving, CPU is not handled by KDE in any way, so if we want (for example) constant powersaving, that isn't happening. 

Expected Results:  
CPU ought to have been under KDE's control (in some way) in order to handle it's powersaving features.

OS: Linux (x86_64) release 2.6.34-ARCH
Compiler: gcc 4.5
Comment 1 Julien Humbert 2010-06-09 22:55:13 UTC 
Same here, I have to set manually in the term the governor I wish to use, KDE uses performance governor each time it starts. Seen in beta 1 and still present in beta 2.

Using Archlinux kde-unstable packages.
OS: Linux (x86_64) release 2.6.34-ARCH
Compiler: gcc
Comment 2 Dario Freddi 2010-06-10 11:59:41 UTC 
This option has been removed on purpose from KDE SC 4.5 after a long discussion on kde-core-devel.
Long story short: this option has been removed since with newer kernels, the ondemand governor should ALWAYS provide the best possible choice depending on the situation.

However, you can still use PowerDevil's advanced capabilities to change your governor: you might already know you can tell PowerDevil to execute a script upon profile change. Making it execute "solid-powermanagement set cpufreq <your governor>" will have the same effect.

Please note that the various input on removing this option was given by people working on the kernel's powermanagement features, so make sure your system isn't already performing/saving enough before you mess with cpufreq.

Hope this helps.
Comment 3 Dario Freddi 2010-06-19 12:02:07 UTC 
*** Bug 242072 has been marked as a duplicate of this bug. ***