Re: [LAU] [Jack-Devel] zombification behaviour...

From: torbenh <torbenh@email-addr-hidden>
Date: Thu Nov 18 2010 - 16:42:55 EET

hi... i thought i take this to lau to get an impression on users
feelings.

here is the story. i basically wanted to improve the heuristics for
client zombification. i wanted jack to only kick clients which take a
whole cpu slice. the result would be that you can overload the cpu
with well behaving clients, and jack would not act on it.

the result in a synchronous jackd (jackd1/tschack or jackd2 -S)
would be continuous xruns, and probably bad noise.

the problem is that its not 100% possible to identify the bad client,
and its always possible, that we might kick an inocent client.

so many people on jack-dev advocate not kicking any client (this is what
jack2 does) jack2 users probably have an SMP system, so jack RT load at
100% doesnt mean their system is unresponsive.

for UP users it might make sense to stop processing after a continous
series of timeouts, so that the user can fix things up.

On Wed, Nov 17, 2010 at 02:50:02PM -0500, Paul Davis wrote:
>
> [ ... ]
>
> there are really 3 possible policies:
>
> 1) ignore all client behaviour (jack2)
> 2) try to zombify the misbehaving client(s) (jack1)
> 3) stop running the process() cycle if there is misbehaviour, and
> restart whenever
> the graph is rechained (indicating that a client has been removed, or
> added, or connections where changed)
>
> torben has been experimenting with an improved version of (2) and with (3)

my argumentation is that if i make the rules for (2) less agressive,
jack might not act up when you overload the cpu.
so i would basically like to protect the user by implementing (3)

after testing the overload situation i think the noise is not so bad.
and i would probably prefer this over silence, if i was on stage.

but UP people might want their cpu freed so they can fix the situation
quickly.

> _______________________________________________
> Jack-Devel mailing list
> Jack-Devel@email-addr-hidden
> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org

-- 
torben Hohn
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-user
Received on Thu Nov 18 20:15:02 2010

This archive was generated by hypermail 2.1.8 : Thu Nov 18 2010 - 20:15:02 EET