Operating System Support for High-Speed Communication

This paper looks at the I/O bottleneck in operating systems, with particular focus on high-speed networking. We start by identifying the causes of this bottleneck, which are rooted in a mismatch of operating system behavior with the performance characteristics of modern computer hardware. Then, traditional approaches to supporting I/O in operating systems are re-evaluated in light of current hardware performance tradeoffs. This re-evaluation gives rise to a set of novel techniques that eliminate the I/O bottleneck. The root cause of the OS I/O bottleneck is that speed improvements of main memory have lagged behind those of the central processing unit (CPU) and I/O devices during the past decade [6]. In state-of-the-art computer systems, the bandwidth of main memory is orders of magnitude lower than the bandwidth of the CPU, and the bandwidths of the fastest I/O devices approach that of main memor