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MPICH - enable debugging prints from `MPIU_DBG_PRINTF()`

What is right order of configuring and running MPICH2 or MPICH-3 to enable debugging prints, embedded to code with MPIU_DBG_PRINTF(). I already used --enable-g=dbg,mem,log configure option, and set environment variable MPICH_DBG_OUTPUT to stdout but still have no debug prints from the examples/cpi runs.

Solution

  • you might need to set a few extra environment variables:

    • MPICH_DBG_LEVEL to VERBOSE
    • MPICH_DBG_CLASS to ALL

    For example:

    mpiexec -n 2 -env MPICH_DBG_OUTPUT VERBOSE \
    -env MPICH_DBG_CLASS ALL \
    -env MPICH_DBG_FILENAME "dbg-%w-%d.log" ./examples/cpi

    The wiki has some more information about the other things you can do with the MPICH debugging facility:

    https://wiki.mpich.org/mpich/index.php/Debug_Event_Logging