SISA: Set-Centric Instruction Set Architecture for Graph Mining on Processing-in-Memory Systems

TL;DR

This paper introduces SISA, a set-centric instruction set architecture designed for graph mining on processing-in-memory systems, significantly accelerating complex algorithms by exploiting set operations and PIM techniques.

Contribution

The paper presents a novel set-centric ISA extension called SISA, enabling efficient execution of set operations for graph mining on PIM hardware, with demonstrated 10x speedups.

Findings

SISA outperforms hand-tuned baselines in graph algorithms.

Set operations are central to complex graph mining algorithms.

SISA achieves over 10x speedup in maximal clique listing.

Abstract

Simple graph algorithms such as PageRank have been the target of numerous hardware accelerators. Yet, there also exist much more complex graph mining algorithms for problems such as clustering or maximal clique listing. These algorithms are memory-bound and thus could be accelerated by hardware techniques such as Processing-in-Memory (PIM). However, they also come with nonstraightforward parallelism and complicated memory access patterns. In this work, we address this problem with a simple yet surprisingly powerful observation: operations on sets of vertices, such as intersection or union, form a large part of many complex graph mining algorithms, and can offer rich and simple parallelism at multiple levels. This observation drives our cross-layer design, in which we (1) expose set operations using a novel programming paradigm, (2) express and execute these operations efficiently with carefully designed set-centric ISA extensions called SISA, and (3) use PIM to accelerate SISA instructions. The key design idea is to alleviate the bandwidth needs of SISA instructions by mapping set operations to two types of PIM: in-DRAM bulk bitwise computing for bitvectors representing high-degree vertices, and near-memory logic layers for integer arrays representing low-degree vertices. Set-centric SISA-enhanced algorithms are efficient and outperform hand-tuned baselines, offering more than 10x speedup over the established Bron-Kerbosch algorithm for listing maximal cliques. We deliver more than 10 SISA set-centric algorithm formulations, illustrating SISA's wide applicability.