Abstract
The MPI-2 Standard, released in 1997, defined an interface for
one-sided communication, also known as remote memory access (RMA). It
was designed with the goal that it should permit efficient
implementations on multiple platforms and networking technologies,
and also in heterogeneous environments and non-cache-coherent
systems. Nonetheless, even 12 years after its existence, the
MPI-2 RMA
interface remains scarcely used for a number of reasons. This paper
discusses the limitations of the MPI-2 RMA specification, outlines
the goals and requirements for a new RMA API that would better meet
the needs of both users and implementers, and presents a strawman
proposal for such an API. We also study the tradeoffs facing the design of
this new API and discuss how it may be implemented efficiently on both
cache-coherent and non-cache-coherent systems.