[Beowulf] progress on ifort and gfortran issue

Nifty Tom Mitchell niftyompi at niftyegg.com
Tue Feb 24 11:00:16 PST 2009

On Tue, Feb 24, 2009 at 05:49:58PM -0000, Paulo Afonso Lopes wrote:
> If you compile your code with -g (debugging support), and "just run"
> normally, it should crash and create a core file in the working dir. (do a
> ls -la to find it)
> If you gdb --core=<your core file here> it will point you to the offending
> instruction (helps if you are running on the dir where you have your
> source code :-) otherwise you should add --directory=<your sources>

Do check user limits to ensure that the size of your core file
is not limited to zero.   On a cluster it is common
to have the core file limit set to zero.  Should a many rank
MPI program dump core the I/O tossed at a NFS server can
boggle the mind.   The value of -g is that symbols are kept
and associated with bits in the binary so a debugger can
interact symbolical with the binary and source code symbols.

$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Also the name of core files can be manipulated 
so each rank has its own core file.

	T o m  M i t c h e l l 
	Found me a new hat, now what?

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