cpufreq and changing driver

Marco Calviani marco.calviani at gmail.com
Wed Nov 30 20:28:09 GMT 2005

Hi Bruno,

> The ondemand governor is basically an implemation of the following
> algorithm:
> There is a counter, say count.
> at each given fixed intervall:
> if (idle less than a watermark) {
>     frequency full
>     reinitialise count to 10
> } else if (idle more than another watermark) {
>     decrement count
>     if count is 0 {
>         down one step the frequency
>     }
> else reinitilize count to 10
> Note that in the latter case, the down step is performed only
> after 10 such comparison.  In other word, intervall is ten times
> larger for the down side than the full frequency one.
> This work well when you can perform, say, 20 to 50 transitions per
> second.  Otherwise, it is pretty bad.

Thanks very much!
 But i'm not understanding if this high number of transitions are a
problem from the hardware point of view or from the software
implementation in freeBSD?

Best regards,

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