Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4]

Lee Revell
2004-10-29T02:19:50Z

On Thu, 2004-10-28 at 20:57 -0400, Paul Davis wrote:
> >> XRUN Rate . . . . . . . . . . . 424 8 4 /hour
> >> Delay Rate (>spare time) . . . 496 0 0 /hour
> >> Delay Rate (>1000 usecs) . . . 940 8 4 /hour
> >> Maximum Delay . . . . . . . . . 6904 921 721 usecs
> >> Maximum Process Cycle . . . . . 1449 1469 1590 usecs
> >> Average DSP CPU Load . . . . . 38 39 40 %
> >> Average Context-Switch Rate . . 7480 8929 9726 /sec
> >
> >looks pretty good, doesnt it?
>
> yes and no. its troubling that we're using an extra 100usecs of time
> for the max process cycle, if the statistics make that number
> meaningful. and why a 30% increase in the context switch rate? is that
> an artifact or a real behavioural change? the xrun rate is not bad,
> although i'd need to know the period size. 4 clicks per hour would
> actually be unacceptable to most professionals, but this may have been
> with significant loading outside of JACK - i don't know.

I would not take these results too seriously yet, they are comparing one
highly experimental kernel to another. Neither of these setups claims
to be ready for professional use yet - we are definitely going for zero
xruns, period, this seems to be achievable with most hardware. I just
left this in to give you some context.

Lee