LinuxFP: Transparently Accelerating Linux Networking

This paper introduces transparent acceleration into the Linux networking stack. To do so, we build on years of research in creating high-performance software-based packet processing systems. Rather than treating these technologies as alternative pipelines, we leverage the technology to create explicit fast paths in the Linux kernel. With this, Linux still serves as a complete implementation of all its supported protocols, but frequent operations on the critical path can be transparently han-dled by a fast path. We implement a controller that continuously introspects the Linux kernel to determine exactly what packet-processing functionality is currently configured. The controller then synthesizes and deploys a minimal fast past into the packet processing pipeline that only implements functionality that is currently needed. In this way, common command line tools, such as brctl, control plane software, such as FRRouting (FRR), and higher-level management frameworks such as Kubernetes and Ansible, work without modification and transparently benefit from a faster network data plane. Our system, LinuxFP, includes a controller that can implement IP forwarding, bridging, and IP filtering fast paths that are synthesized on-demand using their specific and current configuration in the kernel. We evaluate performance improvements using Linux management tools and a Kubernetes network plugin. We show performance improvements over Linux for packet forwarding of 77 % and 20 % for an unmodified Kubernetes network plugin.