Title
Highly Efficient Compensation-Based Parallelism for Wavefront Loops on GPUs
Abstract
Wavefront loops are widely used in many scientific applications, e.g., partial differential equation (PDE) solvers and sequence alignment tools. However, due to the data dependencies in wavefront loops, it is challenging to fully utilize the abundant compute units of GPUs and to reuse data through their memory hierarchy. Existing solutions can only optimize for these factors to a limited extent. For example, tiling-based methods optimize memory access but may result in load imbalance; while compensation-based methods, which change the original order of computation to expose more parallelism and then compensate for it, suffer from both global synchronization overhead and limited generality. In this paper, we first prove under which circumstances that breaking data dependencies and properly changing the sequence of computation operators in our compensation-based method does not affect the correctness of results. Based on this analysis, we design a highly efficient compensation-based parallelism on GPUs. Our method provides weighted scan-based GPU kernels to optimize the computation and combines with the tiling method to optimize memory access and synchronization. The performance results on the NVIDIA K80 and P100 GPU platforms demonstrate that our method can achieve significant improvements for four types of real-world application kernels over the state-of-the-art research.
Year
DOI
Venue
2018
10.1109/IPDPS.2018.00037
2018 IEEE International Parallel and Distributed Processing Symposium (IPDPS)
Keywords
Field
DocType
GPU,wavefront,scan,prefix sum,parallelism,locality,synchronization
Kernel (linear algebra),Synchronization,Memory hierarchy,Wavefront,Prefix sum,Computer science,Parallel computing,Correctness,Operator (computer programming),Computation
Conference
ISSN
ISBN
Citations 
1530-2075
978-1-5386-4369-3
1
PageRank 
References 
Authors
0.35
22
5
Name
Order
Citations
PageRank
Kaixi Hou1855.85
Hao Wang2534.46
Wu-chun Feng32812232.50
Vetter, Jeffrey42383186.44
Seyong Lee568949.44