4.2 performance

[Mark Callow]

We have just converted our Vax 11/750 from 4.1bsd to 4.2bsd.
The system is currently terribly terribly slow.   Since I haven't
seen any other comments about 4.2's performance I hadn't expected
it to be slower.  In fact I expected it to be faster.

The system is slow slow that vi is a pain and you can sometimes
watch individual characters being written to the terminal even
though the baud rate is 9600.  Also I am having troubles with
uucp timing out.  I increased PKTIME in the packet driver but I still
get timeouts.  I was running rtiuucp on 4.1 (which is also the one
distributed with 4.2) and it was absolutely rock solid.  The system
is verging on the unusable and is slower than a Sun running 4.1c

When we changed over to 4.2 we also added a Fujitsu Eagle disk
on a new controller in addition to one rm05.  Having thus introduced
interleaved swapping plus having moved the user file systems to a
second disk arm plus having the 4.2 file system I expected to see a
significant improvement.  I also added an Interlan ethernet controller.

When I was working on the system alone during the conversion work my
feeling was that compilations were significantly faster and that other
things that I was doing (mostly editing) were about the same.

I have watched vmstat and cannot see any sign of excessive interrupts,
context switches, system calls or paging all though I am hampered in
my interpretation of the output because I never looked at it much when we
were running 4.1.  The only noticeable thing is that the cpu idle time
is frequently 0% when our normal load (18 users) is on the system.
I have also looked at ps and have seen what appear to be very low priorities
(eg 75 for ccom).  Are such low priorities to be expected?  One other strange
thing I noticed is that rvcat which is spawned by the new lpr program has
priority -1 even when its status is given as R.  I thought negative
priorities meant a process was waiting for something.

Can anyone give me any suggestions of areas to watch and possible
causes of this slow running.  What are other users' experiences with
4.2?  Any responses are welcome.  I will summarize to the net if
sufficient interest is shown.

For reference our configuration is:
	Vax 11/750 - no fpa, 2MB memory, 2dz11, 2 Emulex dh's,
		   - 1 Interlan 10 Mbit/s ethernet controller
	1 rm05	on massbus 0
	1 tu77  on massbus 1
	1 eagle on massbus 2 using Emulex controller.
	1 lp11 and controller
	1 Versatec v80 and 121 controller
-- 
>From the Tardis of Mark Callow
msc at qubix.UUCP,  decwrl!qubix!msc at Berkeley.ARPA
...{decvax,ucbvax,ihnp4}!decwrl!qubix!msc, ...{ittvax,amd70}!qubix!msc