Out of the box, Linux runs just fine for many uses. But if you find yourself needing to ferret out performance problems or tune the kernel for better performance, Linux has more than enough tools to measure and tweak system performance. In this guide, we'll take a look at five of the best utilities to measure system performance and tweak the Linux kernel. You'll find many, many, many utilities for measuring and improving Linux system performance. The utilities discussed here are chosen because they're widely available, and provide a good scope functionality. Also, I chose to avoid tools that have too steep a learning curve. As an example, SystemTap is a bit more complex than should be covered in an overview article. I left out some of the more basic tools such as ps and top because most Linux users are exposed to them fairly early on. And I didn't try to tackle any application-specific tools.