6 Mar
2005
6 Mar
'05
1:37 p.m.
Jack O'Quin wrote:
"Best" depends on your needs and priorities.
I would accept a kernel that is only used for music. Actually the only
thing I need realtime for is running csound5 in realtime controlled over
midi. I just upgraded from csound4 and performance is better in csound5,
but still I cannot get buffersize lower than 512 (csound-alone-latency:
12ms = too much) without a click every 30 secs or so. csound4 clicked
much more, about every 2 secs, so I'm thinking I'm close, mainly due to
the fact csound5 is able to use the alsa drivers instead of oss-emulation.
To be honest I'm not sure exactly what is the cause of the problem
(which is why I want to see what an optimized kernel will do), I can
think of:
1) kernel.
2) unnecessary services
3) the fact that my soundcard is usb (Edirol UA-1A)
4) csound itself (doubt it)
5) computer. Hope not, it a P4 2.4Ghz laptop
For lowest latency, 2.6.10 with Ingo Molnar's
realtime preemption
patches is currently the best.
That's new for me... You're not talking about this, right?
[atte@aarhus src]$ head linux-2.6.10-rt2.patch
diff -ruN -X /home/joq/bin/kdiff.exclude
linux-2.6.10-rc2-mm3/Documentation/realtime-lsm.txt
linux-2.6.10-rc2-mm3-rt2/Documentation/realtime-lsm.txt
--- linux-2.6.10-rc2-mm3/Documentation/realtime-lsm.txt Wed Dec 31
18:00:00 1969
+++ linux-2.6.10-rc2-mm3-rt2/Documentation/realtime-lsm.txt Wed Nov
24 09:58:29 2004
@@ -0,0 +1,39 @@
+
+ Realtime Linux Security Module
+
+
+This Linux Security Module (LSM) enables realtime capabilities. It
+was written by Torben Hohn and Jack O'Quin, under the provisions of
I tried applying the above patch, but I didn't see anything new under
"security" in the kernel config, so I guess I did something wrong...
Where to get the patches you're talking about, and what to do?
But, that requires considerable effort
on your part.
Not that much, since I'm on a home brewn 2.6.9... This also means that I
have a working alsa setup. If i wen't with 2.4 I would have to install
alsa seperately, so...
A recent, stable 2.6.x kernel is also an easy option.
I'm getting as
good or better LL results with vanilla 2.6.10 than with 2.4.19 and the
LL patches. I have not tried 2.6.11 yet, but expect it to be even
better. IMO, latency is no longer a reason to avoid 2.6 kernels.
As mentioned, I'm already on 2.6.9.
For the easiest solution, go with PlanetCCRMA
(Fedora/RedHat) or
AGNULA/DeMuDi (Debian). They've got this stuff all integrated and
readily available for binary download.
I'm not interrested in "easy" but in "best". I'm on
debian/unstable, so
maybe agnula would be possible. I just want to make sure that my current
system is not "infected" with all kinds of agnula stuff. Is it possible
just to get the low-latency kernel and use on an unstable system?
--
peace, love & harmony
Atte
http://www.atte.dk