PowerTOP tool released; time to fix the wasted laptop power on fedora?

William Cohen wcohen at redhat.com
Mon May 14 14:04:13 EDT 2007

Jordan Crouse wrote:
> On 14/05/07 12:20 -0400, William Cohen wrote:
>> interesting information about power consumption isn't available. The code 
>> attempts to read the ACPI information (/proc/acpi/processor/) for C state 
>> information. Is there some other place that this type of information would be 
>> available on XO machine?
> You mean /proc/acpi/processor/../power specifically?

Yes, it is using /proc/acpu/processor/../power.
> We only support a maximum of "C1" (esentially 'hlt').  Not sure how much
> more of that information it needs.  I'm also not sure how we can report
> the "current C" state. I guess we would need a file of our own.
> If you can figure out what information the app needs, we can either dummy
> it up, or figure out a way around it. :)
> Jordan

With the high-speed suspend/resume is there some counter keeping track of the 
time spent suspended?

I  have a little systemtap script that records when the processor enter and 
leaves C1 state. I guess that something similar could be done to track the 
amount of time in suspend if the suspend/resume doesn't track that information.

PowerTOP is using the /proc/timer_stats. However, there is some useful 
information like the pid that PowerTOP is removing from the output.


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