Subject: Please help me work around nasty quirk in NetBSD 1.2's task scheduling.
To: None <port-amiga@NetBSD.ORG>
From: Rob <dickrp@wckn.dorm.clarkson.edu>
List: port-amiga
Date: 11/30/1996 03:03:18
I posted a few days ago about diffficulty printing when other tasks were
vying for processor time.  If I print on a clean system, I get >4 pages 
per minute.  When I try to print the same file with lpd at `nice = -20'
and some other demanding task at `nice = +20' it takes 4 minutes or more
to print one page.

The BSD scheduling quantum is 10 Hz instead of 60 Hz as in AmigaOS.  As
printing is fast even when other tasks are vying for time under AmigaOS,
I thought that the size of the quantum under BSD might be responsible for
the problem.

I tried changing the scheduling frequency quantum in kern_synch.c
and I have found that increasing the period doesn't help the problem but
reducing the period (to 60 Hz instead of 10) makes printing even slower.

Isn't there some way I can tell NetBSD to service a print job              
whenever it requires it?  When I want to print something, I have to
`kill -STOP' all of the demanding background tasks I have running before I   
can print.  I must be doing something wrong... I can't imagine that this
behavior is intended.      

Thanks to anyone who helps me turn my Amiga back into a multi-tasking machine,

-Robert Dick (dickrp@wckn.dorm.clarkson.edu)-
A3000, '060
NetBSD-1.2
LaserJet 5L