Refereed International Conference Publications

PID-Comm: A Fast and Flexible Collective Communication Framework for Commodity Processing-in-DIMMs [abstract]
Junguk Hong, Si Ung Noh, Chaemin Lim, Seongyeon Park, Jeehyun Kim, Hanjun Kim, Youngsok Kim, and Jinho Lee
The 51st Annual International Symposium on Computer Architecture (ISCA), July 2024.

Recent dual in-line memory modules (DIMMs) are starting to support processing-in-memory (PIM) by associating their memory banks with processing elements (PEs), allowing applications to overcome the data movement bottleneck by offloading memory-intensive operations to the PEs. Many highly parallel applications have been shown to benefit from these PIM-enabled DIMMs, but further speedup is often limited by the huge overhead of inter-PE communication. This mainly comes from the slow CPU-mediated inter-PE communication methods which incurs significant performance overheads, making it difficult for PIM-enabled DIMMs to accelerate a wider range of applications. Prior studies have tried to alleviate the communication bottleneck, but they lack enough flexibility and performance to be used for a wide range of applications. In this paper, we present PID-Comm, a fast and flexible collective inter-PE communication framework for commodity PIM-enabled DIMMs. The key idea of PID-Comm is to abstract the PEs as a multi-dimensional hypercube and allow multiple instances of collective inter-PE communication between the PEs belonging to certain dimensions of the hypercube. Leveraging this abstraction, PID-Comm first defines eight collective inter-PE communication patterns that allow applications to easily express their complex communication patterns. Then, PID-Comm provides high-performance implementations of the collective inter-PE communication patterns optimized for the DIMMs. Our evaluation using 16 UPMEM DIMMs and representative parallel algorithms shows that PID-Comm greatly improves the performance by up to 4.20× compared to the existing inter-PE communication implementations.