Original Problem:
>Error generated from UBPCALC when launched from command line:
>
>
>I/O error : file 'CMDFILE'
>error code: 3/5 (ANS85), pc=0, call=2, seg=0
> 13 File not found
>
>
>Error encountered when launched from job submission form GJAPCTL:
>
>Unaligned access pid=25123 <UBPCALC> va=0x140b73d1 pc=0x121bd120
>ra=0x121b69a0 inst=0xa0c60000
I received a near instaneous response:
There are actually two separate problems there.
One is that the file CMDFILE is not being found and/or is protected
against
access. (I'm guessing the second part because the error code 13 in
/usr/include/errno.h for C programs is "Permission denied").
The other error is that the program was attempting to make an access to
a data
item that isn't aligned on a 4- or 8-byte boundary. This is called an
"unaligned access". Alpha hardware is designed to allow extremely
speedy
access to data aligned on 32-bit (4 byte) or 64-bit (8-byte) boundaries.
Data
that is not aligned to the nearest 4/8 byte boundary is considered
"unaligned".
The access will work, but at a large speed penalty.
Digital UNIX can be set to do three possible things when these are
encountered:
1. Stop the program and core dump with an error message
2. Emit an error message and continue
3. Say nothing.
In cases 2 and 3, the correct access occurs; it's just that the access
is
actually handled by a low-level routine in the OS instead of in the
hardware.
The developers of the application should have done whatever they could
to
prevent those messages from occurring, both by correctly laying out the
data
structures, and by making a setsysinfo(2) call to turn off the unaligned
access
messages.
See the uac(1) man page for info on how to control Digital UNIX's
behavior when
unaligned accesses happen.
Hope this helps,
John
--
John Francini, francini_at_progress.com
I recieved similar replies from:
David J. DeWolfe [sxdjd_at_java.sois.alaska.edu]
and
Sylvain Robitaille
who, along with one other, suggested an SCT newsgroup and checking with
vendor as well as RTFM.
Thanks all!! The programmers appreciated your replies very much.
Jef H. HamLin
Bangor Hydro
Bangor, Maine
Received on Wed Feb 17 1999 - 13:51:16 NZDT