Mainframe-Style Channel Controllers for Modern Disaggregated Memory Systems

TL;DR

This paper proposes mainframe-inspired memory channel controllers as a portable, OS-friendly abstraction for Near-Data Processing in disaggregated memory systems, leveraging cache coherence for enhanced programmability.

Contribution

It introduces a novel memory channel controller abstraction inspired by mainframe systems, enabling OS integration and fine-grained interaction in modern disaggregated memory architectures.

Findings

Provides a portable, OS-centric abstraction for Near-Data Processing.

Utilizes cache coherence for richer programming models.

Facilitates integration without CPU architecture changes.

Abstract

Despite the promise of alleviating the main memory bottleneck, and the existence of commercial hardware implementations, techniques for Near-Data Processing have seen relatively little real-world deployment. The idea has received renewed interest with the appearance of disaggregated or "far" memory, for example in the use of CXL memory pools. However, we argue that the lack of a clear OS-centric abstraction of Near-Data Processing is a major barrier to adoption of the technology. Inspired by the channel controllers which interface the CPU to disk drives in mainframe systems, we propose memory channel controllers as a convenient, portable, and virtualizable abstraction of Near-Data Processing for modern disaggregated memory systems. In addition to providing a clean abstraction that enables OS integration while requiring no changes to CPU architecture, memory channel controllers incorporate another key innovation: they exploit the cache coherence provided by emerging interconnects to provide a much richer programming model, with more fine-grained interaction, than has been possible with existing designs.