<a href="https://lttng.org/">LTTng</a> creator Mathieu Desnoyers seems a
bit trapped in something of a <a
href="https://dictionary.cambridge.org/dictionary/english/catch-22">catch-22</a>.
At the 2026 <a href="https://lpc.events/">Linux Plumbers Conference</a>
(LPC), he led a discussion on the problem he is having in trying to
collaborate with other tracing projects (e.g. <a
href="https://docs.kernel.org/trace/ftrace.html">ftrace</a>, <a
href="https://perfwiki.github.io/main/">perf</a>) in the kernel. The
feedback he has gotten, both over the years and more recently, does not
show a path that would allow him to contribute the 21-year-old
GPLv2-licensed LTTng tracing framework, or, incrementally, features from
it, to the mainline kernel.