powerd doesn't decrease CPU frequency in some cases

[Rui Paulo]

At Mon, 24 Dec 2007 23:16:54 +0200,
Aragon Gouveia wrote:
> 
> Hi,
> 
> | By Rui Paulo <rpaulo at fnop.net>
> |                                          [ 2007-12-24 14:43 +0200 ]
> > Isn't it better to teach est(4) to ignore values that differ in, say,  
> > +/- 5Mhz ?
> 
> I agree my patch isn't ideal.  I was thinking about it today and it might
> be useful to implement something that ignores frequencies whose power
> ratings don't differ by more than X mW.  In my case, both 2201 and 2200 are
> rated to draw 35000 mW.  The question is, in these cases which one of the
> two should be ignored?  Can't ignore both...

I think you can ignore one of them, which one doesn't really matter
because the power levels are the same. I suspect that, in these cases,
the 2001 comes after 2000 in the EST table, so if we ignore a value
already present, 2000 will remain and 2001 will be ignored.

> Sorry Andrey, I missed your patch.  Was a bit overly excited when I saw
> someone else finally experiencing the same problem as me after receiving
> zero response a month ago when I posted about it. :)
> 
> Something I asked in my post a month ago was where does
> dev.cpu.X.freq_levels get its data?  I was thinking it might be something
> that can be addressed with a patched ACPI DSDT?

dev.cpu.0.freq_levels is the combiation of several power/speed
throttling sources, namely, est(4), acpi_throttle(4), etc. The API
that deals with this is cpufreq(8).

Regards.
--
Rui Paulo