A Fast Work-Efficient GPU Algorithm for SSSP

This paper presents a new Single Source Shortest Path (SSSP)
algorithm for GPUs. Our key advancement is an improved
work scheduler, which is central to the performance of SSSP
algorithms. Previous GPU solutions for SSSP use simple work
schedulers that can be implemented efficiently on GPUs but
that produce low quality schedules. Such solutions underutilize the hardware and yield poor work efficiency. Our
solution introduces a more sophisticated work scheduler
that produces high quality schedules while being efficiently
implementable on GPUs.
To evaluate our solution, we use 226 graph inputs from
the Lonestar 4.0 benchmark suite and the SuiteSparse Matrix Collection, and we find that our solution outperforms
the previous state-of-the-art solution by an average of 2.9×,
showing that an efficient work scheduling mechanism can be
implemented on GPUs without sacrificing schedule quality.