What is "lttng"

LTTng (Linux Trace Toolkit Next Generation) is a system software package for correlated tracing of the Linux kernel, applications and libraries. The project was originated by Mathieu Desnoyers with an initial release in 2005. Its predecessor is the Linux Trace Toolkit.

LTTng uses the Tracepoint instrumentation of the Linux kernel, as well as various other information sources such as kprobes, and the Perf performance monitoring counters.

Designed for minimal performance impact and has a near-zero impact when not tracing, it is useful for debugging a wide range of bugs that are otherwise extremely challenging.