Subject: alignment errors on decstation5000 running ultrix 4.2

From: [email-masked]
Date: Mon, 16 Nov 92 07:15:01 -0800

Hi,

postgres 3.1 on a decstation5000/200 running ultrix 4.2 is puking
CONSTANTLY with unaligned access errors. Is there some -D option I can
recompile with to get rid of the problem? Here is a sample error
message; judging from the pc's logged, we are in a tight loop somewhere.
Needless to say, the performance of the backend on this platform is less
than abysmal.

Cheers,
			-- Sean

----- error log sample -----

# uerf | more
                                                  uerf version 4.2-011 (15)

********************************* ENTRY     1.
*********************************

----- EVENT INFORMATION -----

EVENT CLASS                             OPERATIONAL EVENT
OS EVENT TYPE                  250.     ASCII MSG
SEQUENCE NUMBER              33423.
OPERATING SYSTEM                        ULTRIX 32
OCCURRED/LOGGED ON                      Mon Oct 19 14:12:15 1992 EDT
OCCURRED ON SYSTEM                      loos
SYSTEM ID                 x82020220     HW REV: x20
                                        FW REV: x2
                                        CPU TYPE: R2000A/R3000
PROCESSOR TYPE                          KN02/R3000
MESSAGE                                 Fixed up unaligned data access for pid
                                         _14488 (postgres) at pc 0x10021334
--------
--
Sean Levy, n-dim Group, EDRC, CMU, 5000 Forbes Ave, PGH, PA 15213
Email: [email-masked], Phone: +1 412 268 5221, Fax: +1 412 268 5229

---

From: <[email-masked]>
Date: Mon, 16 Nov 92 09:18:30 PST

> Needless to say, the performance of the backend on this platform is less

3.1 had a number of known bugs that could cause this behavior; that
release is no longer supported.  you should install 4.0.1.

4.0.1 also disables the address fixups done by the ultrix kernel, forcing
a coredump if an unaligned access happens.  we don't know of any examples
of this in a 4.0.1 system, but if an unaligned access happens, dumping
core is certainly preferable to having the kernel scramble pointers.

					mike