eBPF-mm: Userspace-guided memory management in Linux with eBPF

TL;DR

This paper presents eBPF-mm, a Linux memory management framework that uses eBPF to enable user-defined policies for page size promotion, improving memory handling based on application profiles.

Contribution

It introduces a new kernel hook point for eBPF programs during page faults and a profiling framework for application-specific memory region optimization.

Findings

Enhanced control over page size promotion using eBPF

Profiles effectively identify hot memory regions for optimization

Framework improves memory management flexibility in Linux

Abstract

We leverage eBPF in order to implement custom policies in the Linux memory subsystem. Inspired by CBMM, we create a mechanism that provides the kernel with hints regarding the benefit of promoting a page to a specific size. We introduce a new hook point in Linux page fault handling path for eBPF programs, providing them the necessary context to determine the page size to be used. We then develop a framework that allows users to define profiles for their applications and load them into the kernel. A profile consists of memory regions of interest and their expected benefit from being backed by 4KB, 64KB and 2MB pages. In our evaluation, we profiled our workloads to identify hot memory regions using DAMON.