Load-balanced pipeline parallelism

Abstract

Accelerating a single thread in current parallel systems remains a challenging problem, because sequential threads do not naturally take advantage of the additional cores. Recent work shows that automatic extraction of pipeline parallelism is an effective way to speed up single thread execution. However, two problems remain challenging - load balancing and inter-thread communication. This work shows new mechanism to exploit pipeline parallelism that naturally solves the load balancing and communication problems. This compiler-based technique automatically extracts the pipeline stages and executes them in a data parallel fashion, using token-based chunked synchronization to handle sequential stages. This technique provides linear speedup for several applications, and outperforms prior techniques to exploit pipeline parallelism by as much as 50%.