[LAU] Realtime Kernel

[Fons Adriaensen]

On Tue, Mar 18, 2008 at 08:00:18PM +0200, Arda Eden wrote:

> That's what i see when i type uname -a :
> Linux melinda 2.6.18.8-86 #2 SMP Mon Feb 11 00:50:59 EET 2008 i686 mobile
> AMD Athlon(tm) XP-M 2200+ GNU/Linux
> 
> So it looks like i don't have realtime support. But i can use any audio
> application without having any xruns or latencies.

Even the standard kernels have 'realtime support' in the
sense that you can have realtime threads. The difference
with the -rt kernels is that the latter will allow you to
push the limits, by making some possibly long kernel code
paths pre-emptable, and by handling interrupts in a more
flexible way.

But today's 'standard' kernels can perform quite well unless
you're unlucky or you want very low latencies.
 
> I changed my /etc/security/limits.conf file as:
> @audio - rtprio 95
> @audio - memlock 512000
> @audio - nice -19

This has no direct relation to the -rt features of the kernel,
but it allows normal users (in the 'audio' group) to create
realtime threads and to lock memory. Without this you would
have to be root to do this.

-- 
FA

Laboratorio di Acustica ed Elettroacustica
Parma, Italia

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