Slow DZ

[utzoo!decvax!pur-ee!purdue!cak]

	We made our first foray into high speed uucp (1200 baud vadic
modem) without crashing under 2.8bsd today. We have a DZ, and
an 11/60 and previously we had crashed every time we tried to use the
vadic.  Today, we started iostat 1 on a terminal, and uucico on
another, and nothing else, and discovered that the system was about 1%
idle on the average. We had to move uuxqt to uuxqt. to prevent it from
starting, because it would crash. ANYTHING would crash the system
(except maybe another iostat; logging in and starting a csh would take
it down). Our DZ did not seem to be such a load under v6; any ideas
why?  This is really an unacceptable situation, help would be
appreciated. Has anyone tried to put the 'pseudo-DMA' DZ driver for the
VAX onto an 11? This might be the solution.  I also have code for a
somewhat more unorthodox DZ driver from UNSW -- they throw away DZ
interrupts completely and poll the device under control of a KW-11P. We
don't have a P, just a K, and no software for it, and I am not really
looking forward to converting both to version 7.
	I tried to debug a crash dump yesterday, and found that some of
the saved PC values pointed into the 040000 page, where there
are no global symbols. A full nm showed that there are symbols
beginning with ~ (excuse my ignorance, but what are those, in relation
to similarly named symbols beginning with _) but the symbols I found
were ridiculous; for example, the trace back showed something like:

	_panic() 
	_trap() 
	_call() 
	~lpclose() 
	~rlread() 
	_trap() 
	_call()

Which makes little, if any sense (I understand the calls and traps,
but...) The crashes are at the same location, always! (620 -- in the
middle of _dump????).

	Also, we tried increasing NMOUNT from 6 to 8. As soon as we
mount the 7th file system (including the root) the system just
goes away somewhere, in a large loop. Haven't figured that one out yet,
either.

HELP!
			Chris Kent (cincy!chris)
P.S. Even though I am writing from Purdue, all the above refers to U of
Cincinnati (cincy on the net). Reply either to cincy!chris or
purdue!cak.