Subject: Audio interrupt latency
To: None <port-arm32@netbsd.org>
From: Charles M. Hannum <mycroft@mit.edu>
List: port-arm32
Date: 08/17/1998 02:55:05
Actually, I can stimulate the lossage even better by playing a file
locally and then, on another machine, doing:

# ping -s 8192 -f chomp

(`chomp' is the Shark...)

The output gets `slow', and I see lots of:

Aug 17 02:50:11 chomp /netbsd: audio: play interrupt(1665) off relative by 19501 us (49970)
Aug 17 02:50:11 chomp /netbsd: audio: play interrupt(1666) off relative by 41575 us (49970)
Aug 17 02:50:11 chomp /netbsd: audio: play interrupt(1669) off relative by 19781 us (49970)

`Something definitely isn't right here.'

BTW, I looked at the way interrupts are handled, and I must say, the
port would benefit a great deal from using a software masking scheme
like the i386 port uses.  Particularly the grotesque ISA IRQ handling.