OpenMPI debugging?

Accelerated Computing HPC Compilers Legacy PGI Compilers
1

I’m trying to debug programs compiled with OpenMPI (v1.1a9).

It sort of works with a command line like:

mpirun --debugger “pgdbg @mpirun@ @mpirun_args@” --debug -np 2 ./cpi

In fact, this starts to debug orterun when the “run” command is entered, but stops automatically at the MPI_Comm_Rank line in my test program. I’m not sure why, but that’s pretty handy.

However, it prints:
db_set_code_brk : DiBreakpointSet fails
many times before it gets to that point and after every “step” command.

Other than that, it seems to be working.

My two questions are:

  1. Does anyone have any experience with debugging OpenMPI apps with pgdbg?
  2. What do the “DiBreakpointSet fails” errors mean and how do I prevent them?

Thanks a lot.
–andy

2

Hi Andy,

Actually I’m pleasantly surprised that PGDBG works at all with OpenMPI since PGDBG currently only supports MPICH. While we’re planning on adding OpenMPI and MPICH-2 support later this year, in the immediate future, there isn’t a work around this problem, other than to use MPICH.

Thanks,
Mat

3

Mat,

I guess I’m glad it works at all, too. :)

We’ll be looking forward to the next version of the compilers/debuggers with support for OpenMPI. If there’s anything we can do to help, we’d be willing to do what we can.

Thanks a lot.

–andy