Self-consistent MPI Performance Requirements

The MPI Standard does not make any performance guarantees, but users expect (and like) MPI implementations to deliver good performance. A common-sense expectation of performance is that an MPI function should perform no worse than a combination of other MPI functions that can implement the same functionality. In this paper, we formulate some performance requirements and conditions that good MPI implementations can be expected to fulfill by relating aspects of the MPI standard to each other. Such a performance formulation could be used by benchmarks and tools, such as SKaMPI and Perfbase, to automatically verify whether a given MPI implementation fulfills basic performance requirements. We present examples where some of these requirements are not satisfied, demonstrating that there remains room for improvement in MPI implementations.