Re: [patch] voluntary-preempt-2.6.9-rc1-bk12-R5

[Ingo Molnar]

* Rui Nuno Capela <rncbc@xxxxxxxxx> wrote:

> b) When CONFIG_SCHED_SMT is not set, I can run all along with
> softirq-preempt=1, hardirq-preempt=1 et al. While running jackd in
> realtime mode, I get NO hard-locks, but unfortunately XRUNs are
> plenty. A real storm. However I've noticed that the whole seems pretty
> much stable, as I didn't experience one single system hang. Regression
> to softirq-preempt=0 and hardirq-preempt=0 dissolves the xrun storm to
> nothing again.

when you set softirq-preempt=1 and hardirq-preempt=1 then you also need
to make the soundcard's IRQ non-threaded via /proc/irq/*/*/threaded
(pick the right one that is your soundcard). E.g. i have a CMI8738-MC6 
on IRQ11, so i'd have to do this:

	echo 0 > /proc/irq/11/CMI8738-MC6/threaded

to mark the soundcard's interrupt as directly-executed.

	Ingo
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