As the demands of computational science and engineering simulations increase, the size and capabilities of High Performance Computing (HPC) clusters are also expected to grow. Consequently, the software providing the application programming abstractions for the clusters must adapt to meet these demands. Specifically, the increased cost of interprocessor synchronization and communication in larger systems must be accommodated. Non-blocking operations that allow communication latency to be hidden by overlapping it with computation have been proposed to mitigate this problem.
In this work, we investigate offloading a portion of the communication processing to dedicated hardware in order to support communication/computation overlap efficiently. We work with the Message Passing Interface (MPI), the de facto standard for parallel programming in HPC environments. We investigate both point-to-point non-blocking communication and collective operations; our work with collectives focuses on the allgather operation. We develop designs for both flat and hierarchical cluster topologies and examine both eager and rendezvous communication protocols.
We also develop a generalized primitive operation with the aim of simplifying further research into non-blocking collectives. We propose a new algorithm for the non-blocking allgather collective and implement it using this primitive. The algorithm has constant resource usage even when executing multiple operations simultaneously.
We implemented these designs using CORE-Direct offloading support in Mellanox InfiniBand adapters. We present an evaluation of the designs using microbenchmarks and an application kernel that shows that offloaded non-blocking communication operations can provide latency that is comparable to that of their blocking counterparts while allowing most of the duration of the communication to be overlapped with computation and remaining resilient to process arrival and scheduling variations. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-05-29 11:55:53.87
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/12215 |
| Date | 30 May 2014 |
| Creators | Inozemtsev, Grigori |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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