forrtl: severe (180): SIGBUS, bus error occurred

[dario_bercioux]

I have installed the intel fortran 9.1.024 on a Power Mac Pro with Intel Core Duo processor. I also have source code of NAG 19 fortran library coming from an old Alpha computer that I have compiled on this Mac computer using Intel Fortran.

Now I an using this routine F02FAF (http://www.nag.co.uk/numeric/fl/manual19/pdf/F02/f02faf_fl19.pdf) that is noting else than a LAPACK routine. After the compilation of the code
I have the following message error:

forrtl: severe (180): SIGBUS, bus error occurred

It is important to mark, that the same program was working of my old laptop with a former version of the intel compiler and a linux distribution.

Dario

[TimP]

This could require some detailed debugging. Among the possibilities are that the Core Duo fails immediately on faulty code which appears to run OK on other processors. I spent the time of several people on such a situation, where an array over-run clobbered the stack. The code ran to apparently satisfactory completion on an earlier model, yet the use of a clobbered address produced immediate failure on the newer CPU. In my case, the error could have been caught by IMPLICIT NONE, or by run-time checking of string and array length.

[Ron_Green]

There are a couple of possibilites, which Wikipedia does a nice job of collecting:

Computer programs may throw SIGBUS for improper memory handling:

invalid address alignment the program has attempted to read or write data that does not fit the CPU's memory alignment rules. non-existent physical address this is equivalent to a segmentation fault, but for a physical address rather than a virtual address. object-specific hardware error this is far less common, however it is present in Solaris, when virtual memory pages have disappeared (e.g. accessing an mmaped file which has been truncated. [1])

What options did you use to build your application AND the NAG library? Particularly, did you use -align? and what -O optimization did you use? And just to be sure, you did you use Intel for compiling the NAG library and your application? and both were built on the Mac?

I think it's good advice to try "-g -checkbounds -traceback" on the compile+build along with your optimization. Then, of course, build it with -O0 -g -check bounds -traceback

As for the last 2 possibilities listed by Wikipedia, the non-exisitent physical memory can only happen if you have a flakey memory DIMM. The last possibilty: I have seen bus errors RARELY with a bad CPU or the seating of the CPU. That is very very rare, though. Just for a sanity check, find a system exerciser - perhaps a LINPACK or some other memory/cpu intensive app and run it for a day to stress the system.

If all this fails to isolate the problem,open a problem report on premier.intel.com

good hunting!

ron