[PD] jack

Larry Troxler lt at westnet.com
Sun Mar 30 01:42:00 CET 2003


On Thursday 27 March 2003 20:42, Antonis Galanopoulos wrote:
> Hi Guenter,
> i got the latest cvs and it works fine. the problem with the moving objects
> is gone although I didnt test that much. It hasn't crashed yet and it is
> running for quite a while now .
> I noticed however that the CPU usage has gone up. It was 2-3 % before and
> it is 9-10 now with the same patch. I guess that has to do with the less
> priority pd now has. Thats not a problem though, I'm just letting you know.
> Thanks very much.

A question for Guenter, or whoever else: how is the CPU usage measured? 
Is it the time at the start of a DSP cycle to the time at the end of the 
cycle, or is it really only the CPU time that the PD process actually uses, 
taking into account that PD could be pre-empted in the middle of the 
processing (I think that before jack, this was probably not an issue before)?


If the latter (true CPU usage is measured), I don't understand it. Why would 
PD's CPU usage increase by that much?

If the former (only the time between the start and end of the processing is 
measured) I suppose it means that PD is being pre-empted, presumably by jack.
But why would this be happening, if PD is fast enough to complete its 
processing in time (and hence not get pre-empted by jack due to timeout)?

Larry Troxler








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