Optimized collectives for PGAS languages with one-sided communication

• Published in: Conference on High Performance Networking and Computing: Proceedings of the 2006 ACM/IEEE conference on Supercomputing; 11-17 Nov. 2006 pp. 143 - 143-es
• Main Authors: Bonachea, Dan, Hargrove, Paul, Nishtala, Rajesh, Welcome, Michael, Yelick, Katherine
• Format: Conference Proceeding
• Language: English
• Published: New York, NY, USA ACM 11.11.2006
• Series: ACM Conferences
• Subjects: General and reference > Cross-computing tools and techniques > Performance; Software and its engineering > Software creation and management > Software verification and validation > Operational analysis; Software and its engineering > Software organization and properties > Contextual software domains > Operating systems > Communications management; Software and its engineering > Software organization and properties > Software system structures > Distributed systems organizing principles
• ISBN: 0769527000; 9780769527000
• DOI: 10.1145/1188455.1188604

Optimized collective operations are a crucial performance factor for many scientific applications. This work investigates the design and optimization of collectives in the context of Partitioned Global Address Space (PGAS) languages such as Unified Parallel C (UPC). Languages with one-sided communication permit a more flexible and expressive collective interface with application code, in turn enabling more aggressive optimization and more effective utilization of system resources. We investigate the design tradeoffs in a collectives implementation for UPC, ranging from resource management to synchronization mechanisms and target-dependent selection of optimal communication patterns. Our collectives are implemented in the Berkeley UPC compiler using the GASNet communication system, tuned across a wide variety of supercomputing platforms, and benchmarked against MPI collectives. Special emphasis is placed on the newly added Cray XT3 backend for UPC, whose characteristics are benchmarked in detail.