Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!mcsun!ukc!newcastle.ac.uk!turing!ncrr
From: C.R.Ritson@newcastle.ac.uk (C.R. Ritson)
Newsgroups: comp.sys.encore
Subject: Multimax thrashing
Keywords: multimax memory sysparam thrashing parameter
Message-ID: <1990Dec3.170300.14750@newcastle.ac.uk>
Date: 3 Dec 90 17:03:00 GMT
Sender: news@newcastle.ac.uk
Organization: Computing Laboratory, U of Newcastle upon Tyne, UK NE1 7RU.
Lines: 34

We have an encore multimax that is overloaded.  We cannot at this time
afford more memory for it.

Every  few  days  at  a  time of high load, the physical memory in use
climbs from its normal 80-90% to 99% and stays there.  No  matter  how
hard  the system swaps (thrashes) it seems to be unable to do anything
to improve the situation.  The only solution is to reboot, and  assume
that this makes some users go away for a coffee.

The  system  paramers  are  largely set to their default values.  Does
anyone have any  hints  about  alternate  settings  that  improve  the
performance under high load?  Are there any known bugs in this area?

For  your  information, incase it might help, here is some information
about our system:

running O/S: Umax 4.3 (R4.1.0) APC NFS Fri Aug 24 15:17:15 1990

Megabytes of memory                                             64
Maximum number of CPUs configured                               8 (4 APCs)

Number of clock interrupts per second                           10
Maximum number of users                                         100
Maximum number of processes per user                            50
Ticks between process timeslice interrupts                      2000

Number of swap buffers                                          64
Microseconds of user virtual time between working set scans     2000000

Chris Ritson
--
PHONE: +44 91 222 8175              Computing Laboratory,
FAX  : +44 91 222 8232              University of Newcastle upon Tyne,
TELEX: uk+53654-UNINEW_G            UK, NE1 7RU