[AG-TECH] Linux PiG - single CPU problem, AG 2.3

Andrew Daviel advax at triumf.ca
Thu Dec 2 23:32:30 CST 2004

I was going to order a single-CPU system for a Linux superPiG (3 cameras
but 1 box for easy VRVS compatability), but now I'm not sure if it will
work... help !

I have AG 2.3 on 3 Linux systems (well, 5 , but I've only seriously tried
the sound on 3)

#1 - dual Athlon 2.4GHz, 512Mb, RedHat 9 - production node, works
tolerably well.
Also runs a lightly loaded webserver plus Mozilla, Acroread etc.

#2 - single P4 2.4GHz, 756Mb, RH 9 - desktop. Also running Mozilla +
various odd shells

#3 - single P3 800Mhz, 256Mb, FC1 - VRVS node. Not much else running.

In the single-CPU machines, Rat media is running at about 97% CPU (it is
on one CPU of the dual, too). If another task eats CPU (e.g. "find /
-exec ls -l {}\;>/dev/null) then the percentage of CPU consumed by Rat
falls and the other task runs properly. So it works OK with VRVS (i.e.
Mozilla and vic). I suspect this is normal Rat behaviour.

If AG2.3 is running, it seems to be blocked or at least slowed by Rat
when changing rooms on the venue server.
With Rat running, it takes four minutes to change rooms (timed on #2) ...

If Rat is re-niced to a lower priority, it does not make any significant
difference. If Rat is killed, the room change proceeds at normal speed
and Rat is re-launched in the new room.

I don't understand what is happening (for that matter, I don't understand
why an audio application needs to run a polling loop while a video
application seems to run nicely on interrupts), but clearly the
single-CPU systems are virtually unusable in a production environment.

Ideas ?

Andrew Daviel, TRIUMF, Canada
Tel. +1 (604) 222-7376
security at triumf.ca

More information about the ag-tech mailing list