Could this be a possible solution to the in-process
xrun issue?
http://www.onlamp.com/pub/a/onlamp/2002/11/07/linux_threads.html
there is no "in-process" xrun issue. the problem is for
"out-of-process" clients. the problem has nothing whatsoever to do
with the pthreads implementation, and everything to do with the kernel
scheduler and worst-case kernel scheduling latencies.
the problem in 2.4.19 has been seen by other people in other
contexts. it may not may not be present in 2.5/2.6 - we don't know
yet. even if its gone, there might be other issues, perhaps new ones,
that surface.
the stuff mentioned in the article about the O(1) scheduler and some
other changes that ingo has made are of some relevance to the problem,
but its not clear how much since nobody has tried JACK on 2.5 AFAIK.
--p