[comp.unix.ultrix] HELP!! Segmentation faults: Ultrix-4.0/ISODE-6.0/OSIMIS-2.1

morse@quark.mpr.ca (Daryl Morse) (10/13/90)

We are trying to bring up (read: keep up) OSIMIS and ISODE on
DECstation 5000s running Ultrix 4.0, but are encountering segmentation
faults under load, as well as lots of noise due to unaligned accesses.
We turned off the unaligned access messages with the uac command, but
the segmentation faults are a brick wall.

My questions are directed at users of OSIMIS and ISODE running
DECstations, as well as DEC software support. We are not sure whether
the segmentation faults are a result of the software or the operating
system. The unaligned access messages are clearly caused by the code.
(The Sun4 compiler has a handy-dandy "-misaligned" flag, which seems
to have averted problems on that platform.) Ultrix supposedly fixes-up
problems due to misalignment on the fly, as the numerous error
messages used to indicate before we shut them off. However, we already
are running a patched version of vm_drum.o, which was necessary to
enable us to run a well-known OO development environment without
crashing the system on a regular basis.

1. Is the runtime fix-up known to be robust under all circumstances,
or will it break under pathological conditions? Will we know if it
breaks?

2. Has anyone been able to get OSIMIS and ISODE to run reliably on a
DECstation (with any version of Ultrix)? If so, did you encounter
similar problems?

3. Are there any known problems with Ultrix 4.0 that cause
segmentation faults? Are any patches available? (We are desperate!)
Could the patch to vm_drum be causing other problems? (Sorry, we
received only a compressed binary, without any official documentation
(ie. no SPR or patch number). I do have the name and email address of
a DEC contact for it, however.)

I will be eternally grateful for any assistance offered. Please reply
via email. I will post the solution when I find it. Thanks.



--
Daryl Morse                     | Voice : (604) 293-5476
MPR Teltech Ltd. 		| Fax   : (604) 293-5787
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