Optimal Data Allocation for Graph Processing in Processing-in-Memory Systems

Abstract

Graph processing involves lots of irregular memory accesses and increases demands on high memory bandwidth, making it difficult to execute efficiently on compute-centric architectures. Dedicated graph processing accelerators based on the processing-in-memory (PIM) technique have recently been proposed. Despite they achieved higher performance and energy efficiency than conventional architectures, the data allocation problem for communication minimization in PIM systems (e.g., hybrid memory cubes (HMCs)) has still not been well solved. In this paper, we demonstrate that the conventional “graph data allocation = graph partitioning” assumption is not true, and the memory access patterns of graph algorithms should also be taken into account when partitioning graph data for communication minimization. For this purpose, we classify graph algorithms into two representative classes from a memory access pattern point of view and propose different graph data partitioning strategies for them. We then propose two algorithms to optimize the partition-to-HMC mapping to minimize the inter-HMC communication. Evaluations have proved the superiority of our data allocation framework and the data movement energy efficiency is improved by 4.2-5 × on average than the state-of-the-art GraphP approach.