Abstract: Software router has played a more and more important role in the development of modern networks, and the Click modular router has been one of the most popular software routers as it provides a good platform for new protocol development and rapid prototyping. Due to external overhead introduced by practical mechanism, I/O performance, which has become a bottleneck, strictly prevents the packet processing capability of Click in the user level. Aiming at the shortcomings of the I/O mechanism in the existing Click modular router, this paper proposes an optimized I/O framework for the Click modular router in the user level, through using the poll mode, zero copy and packet prefetching. The experimental results show that the optimized I/O framework can provide better performance (121 times) than the native.

Key words: software router, Click, I/O, poll mode, zero copy, packets prefetching

摘要： 软件路由器在现代网络的发展中发挥着越来越重要的作用，而Click是具有良好模块化设计的软件路由器，为开发和验证新的路由协议等应用提供了很好的软件平台。由于实现机制问题，用户态Click的I/O性能严重限制报文处理能力，影响以Click软件路由器为平台的系统的整体性能。针对现有Click用户态I/O机制的不足，提出了一种面向用户态Click的I/O优化框架，通过采用轮询技术、零拷贝技术和报文预取技术提升了I/O性能。实验结果表明：优化后的用户态Click的I/O性能提升了121倍。

关键词: 软件路由器, Click, I/O, 轮询, 零拷贝, 报文预取