30 Mar
2006
30 Mar
'06
10:04 p.m.
On Wednesday, 29. March 2006 17:28, Florian Schmidt wrote:
At least on 2.6.15 and 2.6.16, yes (with several different versions of the
realtime patch). I don't think I ever used chrt on a 2.6.12 kernel,
because I hadn't read your "Ramblings on linux audio/midi system setup"
back then :)
I did. I used
various versions of 2.6.12, 2.6.15 and 2.6.16 with the
respective realtime patches, same result.
And i suppose you also had the priorities setup similar to your current
setup right? The preemption check actually checks only for one
class of realtime
violations: Those where the app gives up the cpu volountarily (due to
using non rt safe calls that consequently make the process go to
sleep).
Ok, I see... So these xruns can only be remedied by fixing the apps, not
by changing my system configuration?
There's yet another class of realtime unsafeness:
Simply taking too
long in the process callback. If the period is i.e. 10 ms, and the app
needs 20 ms you get an xrun although the app never gave up the cpu
volountarily.
How do I catch those errors? Using the latency tracer? Or does that only
report latencies within the kernel?
Anyway, I think I could do with some explanation how to use it, and how
to interpret the contents of /proc/latency_trace...
Dominic