Demonstration of Path-Based Packet Batcher for Accelerating Vectorized Packet Processing

Recently, a major challenge on generic multi-core network processing platforms is how to improve packet processing performance. Vector packet processor (VPP) is a modularized and high- performance software framework for building network dataplane applications. The key idea of VPP is to reduce instruction cache (i-cache) misses with vectorized packet processing. However, the packets in a vector may traverse different processing paths in some scenarios. In such case, the vector is split into several smaller vectors, and the per- packet overhead would increase. In this paper, we propose a Path-based Packet Batcher (PPB) to accelerate VPP. PPB is transparent to VPP, and it requires no modification to VPP. Before VPP processes packets, PPB batches the packets based on the processing paths they will traverse. We build a prototype based on FPGA to evaluate the performance optimizations to VPP with PPB. Experiment results show that the reduction of i-cache misses can be up to 57.6% when the batch size is 128.