Planning for Performance: Persistent Collective Operations for MPI



Advantages of nonblocking collective communication in MPI have been established over the past quarter century, even predating MPI1. For regular computations with fixed communication patterns, more optimizations can be revealed through the use of persistence (planned transfers) not currently available in the MPI-3 API except for a limited form of point-to-point persistence (aka half-channels) standardized since MPI-1. This paper covers the design, prototype implementation of LibPNBC (based on LibNBC), and MPI-4 standardization status of persistent nonblocking collective operations...