An analysis of the impact of MPI overlap and independent progress
Ron Brightwell, Keith D. Underwood · 2004
The overlap of computation and communication has long been considered to be a significant performance benefit for applications. Similarly, the ability of MPI to make independent progress (that is, to make progress on outstanding communication operations while not in the MPI library) is also believed to yield performance benefits. Using an intelligent network interface to offload the work required to support overlap and independent progress is thought to be an ideal solution, but the benefits of this approach have been poorly studied at the application level. This lack of analysis is complicated by the fact that most MPI implementations do not sufficiently support overlap or independent progress. Recent work has demonstrated a quantifiable advantage for an MPI implementation that uses offload to provide overlap and independent progress. This paper extends this previous work by further qualifying the source of the performance advantage (offload, overlap, or independent progress).