Subject: random core dumps while swapping
To: None <>
From: David Laight <>
List: tech-kern
Date: 03/17/2003 22:01:45
My sparc system is generating random core file while swapping
heavily.  I don't know if this is a sparc specific fault, or a
generic one - I haven't tried the same test on any other systems.

dmesg gives:
NetBSD 1.6P (GENERIC) #14: Mon Mar 17 17:55:52 GMT 2003
total memory = 65216 KB
avail memory = 56848 KB
using 840 buffers containing 3360 KB of memory
bootpath: /iommu@0,10000000/sbus@0,10001000/ledma@4,8400010/le@4,8c00000
mainbus0 (root): SUNW,TP90: hostid 80260032
cpu0 at mainbus0: TMS390S10 @ 50 MHz, on-chip FPU
cpu0: physical 4K instruction (32 b/l), 2K data (16 b/l): cache enabled

The system is booting diskless, but has swap on a SCSI disk.

I was running the following:
$ ulimit -p 532
$ while sleep 60 & do :; done
and noticed that the shell was reporting that processes had dumped core.
I've also had a 'ps' command dump while the code was active.

The core dumps are typically 'Segmentation fault', or 'Illegal instrcution'
and usually confuse gdb.  I don't get a core dump every time, but have
seen quite few.  I've also had the system lock solid (wouldn't even
break to the prom).

There may be a related problem that /bin/sh sometimes decides that the
while loop should not be executed, but abort after starting 1 sleep.

Anyone seen anything like this?


David Laight: