measuring avg cpu speed while powerd(8) is running

Philip S. Schulz ph.schulz at
Sat Aug 6 17:33:20 GMT 2005

Joost Bekkers wrote:
> Hi
> Is there a way to calculate (over eg. a 5 minute interval) the average amount
> the cpu was throttled? In this case by powerd(8).

No, powerd currently reads the CPU usage periodically and adjusts the 
clock speed based on the current CPU idle value. You can somewhat 
influence the behavior with the options described in the powerd man page.
  powerd does not keep a history of CPU usage and it does not record the 
adjustments it makes. However, you could kind of record powerd 
activities by starting it with the -v option and redirect stdout to a file.

> I was thinking there might be a counter/timer which is linked to the cpu clock,
> but sofar I haven't been able to find one.

Well, you can see the current CPU frequency by looking at dev.cpu.0.freq 
where 0 is the id of the CPU you want to query.



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