Subject: panic: MMU Fault
To: None <port-hp300@NetBSD.ORG>
From: Peter Maydell <>
List: port-hp300
Date: 03/09/1998 00:25:02
A friend of mine is running NetBSD 1.2 on an HP 9000/400t. It appears
to be having some problems with memory management. If a lot of memory
is used (by loading a large image with Netscape, for instance) it will
die with the error:
panic: MMU fault
Stopped at _Debugger+0x6: unlk a6

Also, before this occurred the machine became very sluggish. Attempting
to run ps -awux caused a pause of several seconds. The output claimed
that pagedaemon was using 30% of the CPU. The machine didn't appear to
be thrashing during the pause, but there was disk activity after the 
pause and before the output appeared. Similar pause-disk activity 
effects occurred when attempting to switch to different programs in
various xterms. X would also tend to freeze for a few seconds before

Is this a) a known problem? b) likely to be a hardware error 
c) solvable?

Peter Maydell