[linux-audio-user] Re: jackd "zombified - calling shutdown handler"

Pieter Palmers pieterp at joow.be
Fri Feb 23 09:42:02 EST 2007


grae wrote:
> Well I'm currently testing this to be sure but I think my issue is
> with the "priority" setting of jackd, apparently is has to be above
> 50?
> 
> Currently from the ubuntu repository it defaults to 0  (I
> think...maybe I changed it but not sure why I would) and makes me
> wonder what use it is having a value like that.  Is there any time
> that a person would want a priority of zero, or anything less than the
> "magical" number of 50?  Again, I don't know much about all this stuff
> so I'm always trying to piece it together as I go.
The magic in this number is that this is the default value assigned to 
threaded IRQ handlers (at least on my system by rtirq). This means that 
when you run jackd with a priority higher than 50, it won't be 
interrupted by hardware interrupts from e.g. vga devices or harddisks.

Note that it is best to make sure that the IRQ handler of your ohci1394 
card is higher than the priority you run jack with (I make it 90).

see:
http://freebob.sourceforge.net/index.php/IRQ_Threading_and_Priorities

Another tip: due to libfreebob internals, it is better to use 3 smaller 
periods instead of 2 larger, e.g. -n3 -p256 will probably work better 
than -n2 -p512.


> 
> Anyway, I've been trying for a long time to get a good linux audio
> setup and I think I've finally done it!  Thanks to everyone who works
> so hard on all this great software. :)
> 
you're welcome ;)

Pieter Palmers
FreeBoB developer



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