SystemTap provides free software (GPL) infrastructure to simplify the gathering of information about the running Linux system. This assists diagnosis of a performance or functional problem. SystemTap eliminates the need for the developer to go through the tedious and disruptive instrument, recompile, install, and reboot sequence that may be otherwise required to collect data. SystemTap provides a simple command line interface and scripting language for writing instrumentation for a live running kernel. The instrumentation makes extensive use of the probe points and functions provided in the tapset library. This document describes the various probe points and functions.

In this guide, tapset definitions appear in the following format: name:return (parameters) definition The return field specifies what data type the tapset extracts and returns from the kernel during a probe (and thus, returns). Tapsets use 2 data types for return: long (tapset extracts and returns an integer) and string (tapset extracts and returns a string). In some cases, tapsets do not have a return value. This simply means that the tapset does not extract anything from the kernel. This is common among asynchronous events such as timers, exit functions, and print functions.