It's not that bad. - Some of those are not in-tree, like LTTng and SystemTap. - Tracepoints, kprobes, events, and uprobes are all event libraries used by perf

It's not that bad. - Some of those are not in-tree, like LTTng and SystemTap. - Tracepoints, kprobes, events, and uprobes are all event libraries used by perf or ftrace, just like DTrace had multiple providers (fbt, pid, etc). The real fragmentation is perf and ftrace, since both are in-tree front ends. That's not too bad, and they both have different strengths. eBPF is weird in that it's neither an event library or a front end. It's programmatic capabilities. We're mostly using an out of tree project, bcc, to run it.