[vdr] Re: Kernel-Patch to make VDR undisturbable

[Matthias Loetzke <Matthias@Loetzke.de>]

Andreas Schultz (aschultz@cs.uni-magdeburg.de) schrieb:
> > Do you see a possibility in userspace to make sure that VDR runs
> > undisturbed? I do not. IMHO a kernel modification is unavoidable.
> 
> yep, SCHED_FIFO/SCHED_RR ;-)

I looked further into the kernel-souces, and I agree with you, that it is 
possible.

VDR was never designed to be realtime scheduled, so you will need a completly 
different design.
Doing the nessecary changes therefor will be close as much work as a complete 
rewrite of the VDR code.
It must be _guaranted_ that neither VDR nor the DVB-driver will ever lock 
other processes out under any circumstances. Thats close to impossible with a 
complex programm! (but quiet easy using my kernel patch (which lets VDR 
behave somewhat similar to a realtime process without dangers))

Yes, a rewrite of VDR for rt-scheduling would be the cleanest solution, but 
to stay realistic I do not think anybody is willing to do that work.


Matthias.