Inclusive-PIM: Hardware-Software Co-design for Broad Acceleration on Commercial PIM Architectures

TL;DR

This paper evaluates commercial PIM architectures for accelerating a broad range of primitives across domains, identifies bottlenecks, and proposes hardware-software co-design optimizations to enhance their performance.

Contribution

It introduces a PIM-amenability-test for assessing primitives and proposes co-design strategies to improve PIM performance beyond ML-focused designs.

Findings

Commercial PIMs do not fully realize their potential for diverse primitives.

Hardware-software co-design can significantly improve PIM speedups.

Average PIM speedup increased from 1.12x to 2.49x with proposed optimizations.

Abstract

Continual demand for memory bandwidth has made it worthwhile for memory vendors to reassess processing in memory (PIM), which enables higher bandwidth by placing compute units in/near-memory. As such, memory vendors have recently proposed commercially viable PIM designs. However, these proposals are largely driven by the needs of (a narrow set of) machine learning (ML) primitives. While such proposals are reasonable given the the growing importance of ML, as memory is a pervasive component, %in this work, we make there is a case for a more inclusive PIM design that can accelerate primitives across domains. In this work, we ascertain the capabilities of commercial PIM proposals to accelerate various primitives across domains. We first begin with outlining a set of characteristics, termed PIM-amenability-test, which aid in assessing if a given primitive is likely to be accelerated by PIM. Next, we apply this test to primitives under study to ascertain efficient data-placement and orchestration to map the primitives to underlying PIM architecture. We observe here that, even though primitives under study are largely PIM-amenable, existing commercial PIM proposals do not realize their performance potential for these primitives. To address this, we identify bottlenecks that arise in PIM execution and propose hardware and software optimizations which stand to broaden the acceleration reach of commercial PIM designs (improving average PIM speedups from 1.12x to 2.49x relative to a GPU baseline). Overall, while we believe emerging commercial PIM proposals add a necessary and complementary design point in the application acceleration space, hardware-software co-design is necessary to deliver their benefits broadly.