An Efficient Implementation of the BSP Programming Library for Via

Abstract

Virtual Interface Architecture(VIA) is a light-weight protocol for protected user-level zero-copy communication. In spite of the promised high performance of VIA, previous MPI implementations for GigaNets cLAN revealed low communication performance. Two main sources of such low performance are the discrepancy in the communication model between MPI and VIA and the multi-threading overhead. In this paper, we propose a new implementation of the Bulk Synchronous Parallel(BSP) programming library for VIA called xBSP to overcome such problems. To the best of our knowledge, xBSP is the first implementation of the BSP library for VIA. xBSP demonstrates that the selection of a proper library is important to exploit the features of light-weight protocols. Intensive use of Remote Direct Memory Access(RDMA) operations leads to high performance close to the native VIA performance with respect to round trip delay and bandwidth. Considering the effects of multi-threading, memory registration, and completion policy on performance, we could obtain an efficient BSP implementation for cLAN, which was confirmed by experimental results.