Tracepoints and kernel modules

While debugging, it’s invaluable to be able to trace functions in the Linux
kernel. There are several tools for that task: perf, ftrace (with helper tool
like trace-cmd), bpftrace, etc.

For my own debug of kernel internals and in the last few years to debug the
i915 module for Intel graphics, I usually use tracepoints or dynamic
tracepoints (with perf probe) as the trigger for something I want to trace.

One question I get some times is “how do I trace the initial probe of a
kernel module?”. At that time you (usually) don’t yet have the module …