MicRun: A framework for scale-free graph algorithms on SIMD architecture of the Xeon Phi

Graph algorithms currently play increasingly important roles, especially in social networks and language modeling scenarios. Recently, accelerating graph algorithms by heterogeneous high performance computers with the integrated cores and expanded SIMD lanes has been becoming the mainstream. However, the existing methods, restricted by the low-efficiency grouping strategy and the non-optimized selection mechanism of tile size of a graph, are far below our expectations in many ways. Moreover, there are few convenient integrated tools provided for deploying the graph algorithms on MIC architecture. In this paper, we propose a high-efficiency framework MicRun, which is flexible to be used for graph algorithms on SIMD architecture of the Xeon Phi. There are two key components in MicRun, the Bucket Grouping module and Auto-tuning module. In the Grouping module, an optimization algorithm is designed for splitting graph tiles into conflict-free groups, which can be directly processed on SIMD parallelism. In the Auto-tuning module, a novel strategy is proposed for optimizing the tile size to boost execution efficiency of the graph computation. MicRun currently supports Bellman-Ford and PageRank algorithms, we also conduct extensive validation experiments on MicRun. Experimental results show that MicRun outperforms existing mechanisms in terms of storage and time overhead. As a consequence, both graph algorithms achieve an average speedup of 1.1× by MicRun, compared with the state-of-the-art.