mpiP is a lightweight profiling library for MPI applications developed by LLNL and ORNL. Because it only collects statistical information about MPI functions, mpiP generates considerably less overhead and much less data than tracing tools. All the information captured by mpiP is task-local. It only uses communication during report generation, typically at the end of the experiment, to merge results from all of the tasks into one output file. We have tested mpiP on a variety of C/C++/Fortran applications from 2 to 208K processes, including an 8000-process run on the LLNL dawn BG/P system and a 208K-process run on the LLNL BG/L system. Within VI-HPS, LLNL is the main contact for mpiP.
LLNL and ORNL