Sorry if this is an obvious question, but I'm short of time today and
really tired of Google searching.
Linux dlm-A6200 3.2.0-54-lowlatency #56-Ubuntu SMP PREEMPT Thu Sep 19
17:22:47 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
I have jack 2 connected via ALSA to an M-Audio Fast Track Pro.
If there is any slight glitch in the USB power -- for instance, in a
performance space where the sound engineer might need to plug/unplug cables
frequently -- jackd spins out of control on one CPU and often locks up the
user interface, forcing a hard shutdown and reboot. If I'm very lucky, I
can get into the terminal, find jack's PID and kill it, but when the mouse
and keyboard stop responding, there's nothing I can do reach for the power
This occurs less frequently in 12.04 than it did when I started with 10.04,
but when it does happen (as it did just now), it really, really ticks me
I think there must be some automated way for the system to recognize that
jack is out of control and kill it.  notes:
-t, --timeout int
Set client timeout limit in milliseconds. The default is
msec. In realtime mode the client timeout must be smaller
the watchdog timeout (5000 msec).
Interesting... "watchdog timeout"... but I have never seen any effect from
the watchdog mentioned here. Jack just keeps locking up the system for way
longer than 5 seconds.
I'm happy to provide more info if you can tell me what commands to run.
Normally I would research it myself, but I'm just not in the mood today. If
there's already good documentation on this, great, but... too many pages to
read and I have no idea which is the best one.
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