Title: MPI and beyond: Communication paradigms for large irregular communication patterns

Speaker: Brian Barrett, Graduate Student, Open Systems Lab, Indiana University

Date/Time: Wednesday, August 15, 2007, 9:00 am - 10:00 am (MT)

Location: JCEL 899, Room  1702 (Sandia NM),
Video-Conference to CA:  915/S101 8:00 - 9:00 a.m. CA time.

Brief Abstract: This talk will discuss the implementation and application of MPI one-sided operations for irregular and asynchronous communication patterns.  Carried out as part of the Open MPI project, the one-sided interface was the final piece of MPI-2 support to be added and was included as part of the Open MPI 1.2 release.  Open MPI is a portable high-performance implementation of the MPI-1 & MPI-2 standards, and supports most modern high-performance networks, including InfiniBand and Myrinet.  These different networks have different remote memory access mechanisms and I will discuss some of the resulting implementation challenges for supporting one-sided operations.

With one-sided support in place, we compared the use of MPI point-to-point and one-sided communication for supporting distributed-memory computation for large-scale graph problems. While both approaches appear to be sufficient building blocks, a new communication paradigm that exploits the growing ratio between computational power and memory bandwidth is necessary to continue increasing the scalability and performance of graph computations.