Revisiting Trim for CXL Memory

Abstract

The expansion of memory disaggregation, driven by datacentric applications, increases heterogeneity in memory systems. This shift enables the use of inexpensive, yet lifetimelimited, flash memory to be used as a memory expansion module. We argue that TRIM should be introduced into memory management systems to effectively respond to this transition. In this position paper, we explore the potential adoption of flash memory as memory expansion and present an analytical model that offers a straightforward yet rigorous evaluation of TRIM's effectiveness. Using this model and characteristics extracted from real-world workloads, we evaluate the effectiveness of TRIM in scalable memory systems and prove its necessity.