On Wed, Apr 06, 2005 at 08:49:15AM +0200, Frank Behrens wrote: > Bruno Ducrot <[EMAIL PROTECTED]> wrote on 4 Apr 2005 19:17: > > You may start looking at src/usr.sbin/powerd in -current, and improve it > > a bit? The actual algorithm used in powerd may need some rework IMHO. > > Which problems do you see?
powerd use an exponentional decrease of the frequency. This might be not stable for certain workload. > My comments: > 1. If the frequency is raised it should not go down immediately on > short idle phases. To raise the frequency the current idle value > should used but to lower the frequency we should calculate a weighted > idle average value. It might be a solution. It has been tested in that paper: http://www-mtl.mit.edu/research/icsystems/pubs/conferences/2001/sinha_vlsi2001.pdf and it seems it's maybe not the better one, though (search 'MAW', its exactly what you suggest). > 2. The default polling time of 500 ms seems to be very short. It can > increased to several seconds. Problem if you increase teh polling intervall is that you can't be sure that the system can detect in time when going up. -- Bruno Ducrot -- Which is worse: ignorance or apathy? -- Don't know. Don't care. _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
