D. Buntinas, G. Mercier, and W. Gropp, "Implementation and Evaluation of Shared-Memory Communication and Synchronization Operations in MPICH2 using the Nemesis Communication Subsystem," Parallel Computing, vol. 33, no. 9, Elsevier, 2007, pp. 634-644, March 2007. [pdf]
This paper presents the implementation of MPICH2 over the Nemesis communication subsystem and the evaluation of its shared-memory performance. We describe design issues as well as some of the optimization techniques we employed. We conducted a performance evaluation over shared memory using microbenchmarks. The evaluation shows that MPICH2 Nemesis has very low communication overhead, making it suitable for smaller-grained applications.