IPMPI: Improved MPI Communication Logger

Most parallel profilers reveal only the MPI point-to-point communication patterns in a communication matrix. However, this may lead to sub-optimal process mapping due to incomplete information about the application communications. In this work, we have developed a profiler, IPMPI, that reveals the complete communication information including collective communications. We compare the results of two recent process mapping tools, TopoMatch and LPMS, with and without the input from IPMPI. We have run six applications and benchmarks such as ROMS, LAMMPS, DFT, HPCG, miniAMR and miniFE on two supercomputers and our shared department cluster. We observed a maximum average gain between 5.7 - 8.6% across these systems.