Programming models like CUDA, OpenMP, OpenACC and OpenCL are designed to offload compute-intensive workloads to accelerators efficiently. However, the naive offload model, which synchronously copies and executes in sequence, requires extensive hand-tuning of techniques, such as pipelining to overlap computation and communication. Therefore, we propose an easy-to-use, directive-based pipelining extension for OpenMP to overlap data transfers and kernel computation. This extension can map data to a pre-allocated device buffer and can automate memory-constrained array indexing and sub-task scheduling. We evaluate a prototype implementation of our approach with three different applications. The experimental results show that our approach can reduce memory usage by 52% to 97% while delivering a 1:41X to 1:65X speedup over the naive offload model.
['Xuewen Cui', 'Thomas R. W. Scogland', 'Bronis R. de Supinski', 'Wu-chun Feng']
Directive-Based Pipelining Extension for OpenMP