Understanding Roadblocks in Virtual Network I/O: A Comprehensive Analysis of CPU Cache Usage

One big challenge in cloud-native network functions (CNFs) is the poor performance of packet forwarding. In this paper, we comprehensively analyze CPU cache usage in regard to the interprocess communication (vhost-user) as well as the packet I/O framework (DPDK). We cover four high-end CPUs, and examine 141 implementation/configuration patterns on an EIVU (Essential Implementation of Vhost-User) platform to clarify how the patterns affect the cache behaviors. The result pinpoints the roadblocks in a generalized form; cache invalidations stemming from three design/implementation factors are the major bottle-necks in vhost-user/DPDK, and shows potential of 100+ Mpps container networking for future software-centric environment.