BoostN: Optimizing Imbalanced Neighborhood Communication on Homogeneous Many-Core System

MPI neighborhood communication with sparse and imbalanced patterns is common in process-level parallel programs. However, these programs often encounter significant performance slowdowns in today's many-core clusters that feature dozens of cores per node. There are two key causes for this slowdown. First, there is substantial competition for memory and network ports when a large number of processes simultaneously access the MPI library. Second, many neighborhood communications do not align well with the many-core architecture, resulting in performance bottlenecks that could have been mitigated.