On Fri, 2004-04-16 at 10:49, Fernando Pablo Lopez-Lezcano wrote:
There are a couple more issues that pertain to doing
"professional"
audio under 2.6.x that are not addressed by the current Fedora Core
kernel builds, AFAIK
If you are concerned about latency (ie: using very small audio buffers)
then the stock configuration of the 2.6.x kernel has the preemptible
kernel option turned off. In my tests latency is worse than with it
on[1].
That's a showstopper for doing serious MIDI and DAW stuff. Preempt must
be turned on for any kind of serious work in that field.
So, the stock 2.6 has it turned off. How about the FC2 pre-releases? Do
they also turn it off?
If you want to use the Jack low latency audio server (Jack Audio
Connection Kit) with realtime privileges (SCHED_FIFO) then the obvious
alternative is to build and load the LSM kernel module[2]. Regretfully
that would need CONFIG_SECURITY_CAPABILITIES to be a module instead of
being built into the kernel, as in the last build I tried (otherwise you
can't build the LSM module).
If i run JACK as root, do i still need the LSM module?
Currently i run all the audio/MIDI stuff as root, since security is not
an issue on that system, and this way i don't ever see any of the
privilege issues that normally come up.
It's not elegant, though, i admit it.
--
Florin Andrei
http://florin.myip.org/