Analysis of Linux Kernel Packet Processing on Manycore Systems

Due to increased demand for high scalability and programmability in recent data centers, there has been a paradigm shift from traditional hardware-based network functions to software defined network functions. While implementing network functions in software offers great flexibility, it also reveals significant overheads and performance issues associated with the network stack in current operating systems. Since manycore processors and advanced network technology can provide significant performance improvements for applications such as router workloads that are responsive to parallelism, there is a need to optimize the packet processing performance of current operating systems. The network stack in the operating systems suffer from a number of overheads associated with core mechanisms of the kernel such as task scheduling, memory management, process synchronization, interrupt handling, etc. Each of these overheads snowballs into severe performance penalty of software network functions as each packet traverses its path through the network stack in the kernel. In this paper, we provide an analysis of the packet processing capability of manycore systems, running general-purpose operating system (OS). We identify the major performance bottlenecks in the packet processing path of Linux kernel network stack and provide an insight into various performance and scalability issues that need to be addressed.