Call For Testing: pm-utils-powersave-policy

Amit Kucheria amit.kucheria at
Fri Mar 19 07:58:12 GMT 2010

On 10 Mar 18, Chase Douglas wrote:
> Hello all,
> I've been working on some fixes, additions, and cleanup to the current
> pm-utils-powersave-policy package that's slated for inclusion in
> Lucid. The package takes some of the good stuff from the old
> laptop-mode-tools package and moves it to policy scripts that are
> invoked by pm-powersave when on battery power. The items currently
> include:
> * 10 second audio codec power down (vs no power down)
> * 1 minute console (tty1) screen powersave timeout
> * 60 (vs 15) second dirty page writeback timeout
> * Disable WOL for ethernet devices
> * Enable SATA link power save mode (when swapping is unlikely)
> * Enable multi-thread and multi-core power save mode
> To test these changes, please add my powersave ppa
> (ppa:chasedouglas/powersave) and upgrade the pm-utils and
> pm-utils-powersave-policy packages. When you transition from AC to
> battery power these scripts will fire and log what they did (if
> anything) to /var/log/pm-powersave.log. You can also test by running
> 'sudo pm-powersave true' to enable power saving, or 'sudo pm-powersave
> false' to disable power saving.
> One easy way to gauge power savings is to install powertop and execute
> while on battery power:
> $ sudo sh -c "sleep 30; powertop -d -t 30"
> This will wait 30 seconds and then retrieve power information for 30
> seconds. During this time you should not use your laptop as we are
> trying to get a steady-state result. It wouldn't hurt to run this a
> few times to ensure the results are consistent. In the output you
> should find a "Power usage (ACPI estimate)" wattage that describes how
> much energy is used by the system.
 You forgot to note that these scripts are only triggered on ACPI event for
 AC and battery (IOW, when the AC power is plugged in or pulled out).

 So, in essence they're only 'enabled' when on battery and thus targetted at
 laptops, netbooks.


> I am interested in hearing whether the scripts seem to be doing their
> job by looking at the pm-powersave.log file and the power usage. A
> comparison to Karmic power usage would also be helpful, but not
> necessary.
> Thanks,
> Chase
> -- 
> ubuntu-devel mailing list
> ubuntu-devel at
> Modify settings or unsubscribe at:

Amit Kucheria, Kernel Engineer || amit.kucheria at

More information about the ubuntu-devel mailing list