Scheduling Issues with Multimedia Apps

[Loren M. Lang]

Certain tasks that have been doing on FreeBSD like installing ports seem
to interrupt my music playing.  Particually when portupgrade is
extracting/checksumming and when it is updating the package database.
Now to try and solve this I tried to set xmms to use realtime priority
and made it setuid root.  According to top it's running at priority 20
nice -76 so it seems to be running realtime, but portupgrade can still
interrupt the audio occasionally.  I've tried nicing portupgrade before,
but I usually forget, though I'm not even sure if nicing it fixed the
problem.  I've had this problem with FreeBSD 4.9 to 5.3 on two
completely different machines.  Also I've had to stop distibuted.net
running before because I couldn't play movies with mplayer smoothly.
This was on a P4 3.0 GHz, 1G DDR 400 MHz ram.  dnet always runs with a
nice value of 20 which puts it at about priority 131.  Why are these
programs able to interrupt my multimedia programs so much.  The
multimedia programs don't need to use much CPU time with systems as fast
as these, but they just need to make sure they get X work done in Y
amount of time.  If their scheduled apropriately there should be no
conflicts, I've never really had this issues with linux, AFAIK.  Is
there any better way to fix this?
-- 
I sense much NT in you.
NT leads to Bluescreen.
Bluescreen leads to downtime.
Downtime leads to suffering.
NT is the path to the darkside.
Powerful Unix is.

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