Messages in this thread | | | Date | Fri, 29 Oct 2004 13:36:52 +0200 | From | Ingo Molnar <> | Subject | Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] |
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* Paul Davis <paul@linuxaudiosystems.com> wrote:
> >my main suspicion is that either the main jackd thread itself calls the > >kernel where the kernel (unexpectedly for jackd) schedules away for > >whatever reason, or that the chain of wakeup in the audio path somehow > >gets violated (i.e. a kernel problem). There's one quick thing we could > > the "max delay" measurement isn't a reflection of the runtime activity > of jackd. its simply a measurement of the delay between when jackd > expected to be next woken from poll and when it actually was. > > as you noted, jackd generally goes back to sleep in poll typically a > long time before the next interrupt is expected. hence any delay in > the wakeup is between the interrupt handler and the scheduler getting > jackd's main thread back on the processor. i think.
this brings up the next question: does the jackd measurement also timestamp the time when it calls poll() - hence detecting in-jackd processing delays? If yes, which value is this from Rui's stats? If not then it might make sense to add it.
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