Performance Evaluation of Pipelined Communication Combined with Computation in OpenCL Programming on FPGA

In recent years, much High Performance Computing (HPC) researchers attract to utilize Field Programmable Gate Arrays (FPGAs) for HPC applications. We can use FPGAs for communication as well as computation thanks to FPGA's I/O capabilities. HPC scientists cannot utilize FPGAs for their applications because of the difficulty of the FPGA development, however High Level Synthesis (HLS) allows them to use with appropriate costs. In this study, we propose a Communication Integrated Reconfigurable CompUting System (CIRCUS) to enable us to utilize high-speed interconnection of FPGAS from OpenCL. CIRCUS makes a fused single pipeline combining the computation and the communication, which hides the communication latency by completely overlapping them. In this paper, we present the detail of the implementation and the evaluation result using two benchmarks: pingpong benchmark and allreduce benchmark.