how to get cpu states more than once a second?

Bernd Walter ticso at cicely12.cicely.de
Wed Mar 3 02:23:48 PST 2004


On Wed, Mar 03, 2004 at 07:57:24PM +1100, Peter Jeremy wrote:
> On Wed, Mar 03, 2004 at 07:27:31AM +0100, Bernd Walter wrote:
> >Currently I get the states via kern.cp_time, but this only allows
> >a granularity of a single second and I need something around 50-100ms.
> 
> As far as I can tell - both by studying the source code and by
> running "sysctl -x kern.cp_time" in a loop - kern.cp_time increments
> continuously.  statclock() increments the relevant element in the
> array by one at a rate of stathz (128Hz by default).

Yes - my fault - the limit was selfmade...
 
> Obviously, you need to smooth the result over a period substantially
> longer than 1/128 second to get a useful result (unless you want to
> pulse-width modulate your display) but 12.8Hz (stathz/10) would give
> you 10 samples which would be ideal for a 10-segment bargraph.

It's a 16-segment USB which does the modulation itself.
I only need to send a 16bit bitmask.

-- 
B.Walter                   BWCT                http://www.bwct.de
ticso at bwct.de                                  info at bwct.de



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