Hi PostgreSQL developers!
There have already been some reports about the mysterious Bus error
that postmaster dies with on some architectures. Since that bites
pretty hard, I did some investigations and tests on various
architectures with various configurations.
As background, Debian currently builds with gcc 4.0.2 by default, and
I use the latest 7.4.9 and 8.0.4 PostgreSQL versions. The default is
to build with -O2.
Here are the results:
* On i386, PowerPC, AMD 64, S/390, arm, and Alpha all versions work
fine with all tested compiler versions (gcc 3.3.3 and 4.0.2).
* On IA 64, HP PARISC, and sparc postmaster 7.4 and 8.0 fail with a
bus error when ran from initdb. It works fine as soon as I
- build with gcc 3.3 or
- build with -O0 or
- run postmaster through initdb under gdb (grumpf) or
- run postmaster through initdb under strace or
- run postmaster directly (not through initdb).
Yay Heisenbugs. :-/
Also, at least 8.1 on sparc works also well with gcc 4.0 and -O2.
* And then there is MIPS, which really sucks. It constantly crashes
in all configurations I tried it with:
8.0 with gcc-4.0 -O2
8.0 with gcc-4.0 -O0
8.0 with gcc-3.3 -O2
8.0 with gcc-3.3 -O2 and --disable-spinlocks
7.4 with gcc-4.0 -O2 original without any patches
7.4 with gcc-3.3 -O2 with recent MIPS spinlock patch
This also produces an usable backtrace:
Starting program:
/home/mpitt/8.0/postgresql-8.0-8.0.3/debian/tmp/usr/lib/postgresql/8.0/b=
in/postmaster
Program received signal SIGBUS, Bus error.
0x006e4f80 in InitializeGUCOptions () at guc.c:2360
2360 *conf->variable =3D
conf->reset_val;
(gdb) bt
#0 0x006e4f80 in InitializeGUCOptions () at guc.c:2360
#1 0x005c7f68 in PostmasterMain (argc=3D1, argv=3D0x100539e0) at postma=
ster.c:439
#2 0x0056f874 in main (argc=3D1, argv=3D0x100539e0) at main.c:268
Some weeks ago I tracked down the particular variable it fails on
(some float variable; unfortunately I forgot the name, but if it is
important, I can redo the research), but I did not find any
datatype mismatch or similar obvious things.
Does anybody have an idea about these bus errors? Also, if somebody
wants to track down the MIPS bug: I can offer temporary ssh access to
a Debian sid with all required build dependencies, gdb, and the like
for debugging.
Thanks and have a nice day!
Martin
--=20
Martin Pitt http://www.piware.de
Ubuntu Developer http://www.ubuntu.com
Debian Developer http://www.debian.org
In a world without walls and fences, who needs Windows and Gates?
