The power of batching in the Click modular router.

The Click modular router has been one of the most popular software router platforms for rapid prototyping and new protocol development. Unfortunately, its internal architecture has not caught up with recent hardware advancements, and the performance remains sub-optimal in high-speed networks despite its benefit of flexible module composition. In this work, we identify the performance bottlenecks of the existing Click router and extend it to scale with modern computer systems. Our improvements focus on both I/O and computation batching, and include various optimizations for multicore systems and multi-queue network cards. We find that these techniques improve the performance by almost a factor of 10, and the maximum throughput reaches 28 Gbps of minimum-sized IPv4 packet forwarding speed on a single machine.