powerd(8)

Alexander S. Usov A.S.Usov at kvi.nl
Wed Apr 20 17:40:45 PDT 2005


Eric Anderson wrote:
> Ok, I've attached my tweaks to PHK's adaptive.  I run it like this:
> 
> /usr/sbin/powerd -a max -b adaptive2 -p 100 -r 20
> 
> Seems to do a pretty decent job at being responsive, yet gives me a longer
> battery time than the default adaptive.  Not perfect, but still better I
> think..

This one works quite nicely, but you should add an additional check that
your index "i" is not bigger that "numfreqs-1" when you are going to
decrease a speed.

But in general, it looks that a main problem with original adaptive
algorithm is that it is possible to decrease an effective cpu frequency
to an incredibly small values (for mine centrino it can go from 1.3Ghz
down to 75Mhz), where even the easiest things take a lot of time, so it
is forced to increase it. It looks that just limiting the minimal frequency
by a something like 200-300 Mhz should make the original adaptive algorithm
work much better.

-- 
Best regards,
  Alexander.



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