A Case Study of Communication Optimizations on 3D Mesh Interconnects

Optimal network performance is critical to efficient parallel scaling for communication-bound applications on large machines. With wormhole routing, no-load latencies do not increase significantly with number of hops traveled. Yet, we, and others have recently shown that in presence of contention, message latencies can grow substantially large. Hence task mapping strategies should take the topology of the machine into account on large machines. In this paper, we present topology aware mapping as a technique to optimize communication on 3-dimensional mesh interconnects and hence improve performance. Our methodology builds upon the idea of object-based decomposition used in Charm++ which separates the processes of decomposition from mapping of computation to processors and allows a more flexible mapping based on communication patterns between objects. Exploiting this and the topology of the allocated job partition, we present mapping strategies for a production code, OpenAtom to improv...

• Type: Conference
• Year: 2009
• Where: EUROPAR
• Authors: Abhinav Bhatele, Eric J. Bohm, Laxmikant V. Kalé
• Keywords: Distributed And Parallel Computing, EUROPAR 2009, Large Machines, Task Mapping Strategies, Topology Aware Mapping