OmpSs@FPGA: An Open Source Framework for Programming FPGA Clusters

Field Programmable Gate Arrays (FPGA) have seen an increase in popularity in High-Performance Computing (HPC) environments due to their high flexibility and energy efficiency. However, the adoption of these devices for HPC application acceleration is relatively new, and their application is still focused on niche applications mainly due to the programmability issues FPGAs have traditionally faced. In this work, we present an open-source toolchain with support for different FPGA devices and memory topologies, and for implicit and explicit message-passing multi-node and multi-FPGA programming models, which, to the best of our knowledge, is the first of its kind available. The presented toolchain tries to address the increased complexity of programming newer multi-die devices using High-Bandwidth Memory (HBM) by proposing and evaluating HBM design strategies as well as inter-FPGA communication. In addition to presenting the framework characteristics, we evaluate its performance results over a cluster of FPGAs for a set of HPC application benchmarks delivering performance improvements over previous implementations in both single and multi-node versions. The presented framework is an ongoing effort to solve the lack of mature tools and ecosystems that allow programming large clusters of FPGAs, and consequently make scaling applications across multiple FPGA devices a simpler task.