Re: Documentation request - realtime abilities and how to use them

[Tim Janik <timj gtk org>]

On Fri, 13 Feb 2004, Henning Sprang wrote:

> > [...]
> >
> > but giving hard round-robin rt-priorities (like with
> > sched_setscheduler(2))
> > to a desktop application like beast is _not_ right. basically, with
> > round-robin scheduling, beast threads would always run when needed, but
> > also would get run if the code runs into a buggy endless-loop (e.g. within
> > a LADSPA plugin), causing the machine to effectively halt.
> > i.e. SCHED_RR or SCHED_FIFO is unly usefull if you can guarantee to some
> > extend that your application is almost bug free. that's comlpetely
> > impractical
> > for an ordinary desktop application that loads third-party plugins though.
>
> hmm, just a quick thought that springs up my mind but could be completely
> wrong:
> for a professional user it might be less of a problem if the whole system
> crashes when trying some crazy new ladspa plugin than if anything disturbs him
> when just being on doing a master record for some work.
>
> But i can'tr estimate now which case happens more often and which one is
> really more disturbing - a master record can be repeatd easily too, or one can
> integrate ways to get the work into a wav file that doesn't mind if running in
> realtime.
>
>
> But my question derived from me thinking beast has those possibilities
> already. So I come to a nes question: how do i avoid cliking and hanging, which
> occurs for me even in the Party monster sample song, when just swithcing in the
> beast gui from one synthesizer view to another while playing - this should
> really not happen, an d setting nice to -20 doesn't help, either.
> Or is it quite normal that this doesn't work on a 2000 MHZ processor?.

no, that's also related to kernel latency and some other factors.
you'll get the best behaviour with a 2.6 kernel and nicing.
short of running 2.6 however, try increasing the latency setting in
the "Device Monitor" dialog.

>
> Henning
>

---
ciaoTJ