Making way for Linux In The Enterprise

The first step in improving Linux performance is quantifying it. But how exactly do you quantify performance for Linux or for comparable systems? In this article, members of the IBM Linux Technology Center share their expertise as they describe how they ran several benchmark tests on the Linux 2.4 and 2.5 kernels late last year.

The Linux operating system is one of the most successful open source projects to date. Linux exhibits high reliability as a Web server operating system, and it has significant market share in this market. Web servers are typically low-end to midrange systems with up to 4-way symmetric multiple processors (SMP); enterprise-level systems have more complex requirements, such as larger processor counts and I/O configurations and significant memory and bandwidth requirements. In order for Linux to be enterprise-ready and commercially viable in the SMP market, its SMP scalability, disk and network I/O performance, scheduler, and virtual memory manager must be improved relative to commercial UNIX systems.

The Linux Scalability Effort (LSE) (see Resources for a link) is an open source project that addresses these Linux kernel issues for enterprise class machines, with 8-way scalability and beyond.

The IBM Linux Technology Center's (LTC) Linux Performance Team (see Resources for a link) actively participates in the LSE effort. In addition, their objective is to make Linux better by improving Linux kernel performance with special emphasis on SMP scalability.

This article describes the strategy and methodology used by the team for measuring, analyzing, and improving the performance and scalability of the Linux kernel, focusing on platform-independent issues. A suite of benchmarks is used to accomplish this task. The benchmarks provide coverage for a diverse set of workloads, including Web serving, database, and file serving. In addition, we show the various components of the kernel (disk I/O subsystem, for example) that are stressed by each benchmark.