GDB*: The GNU* Project Debugger

Use the following command to launch the GDB* debugger with Intel® MPI Library:

$ mpirun -gdb -n 4 ./testc

You can work with the GDB debugger as you usually do with a single-process application. For details about how to work with parallel programs, see the GDB documentation at http://www.gnu.org/software/gdb/.

You can also attach to a running job with

$ mpirun –n 4 -gdba <pid>

Where <pid> is the process ID for the running MPI rank.