[exikyut]

`perf top` on Linux, and doing a (really) deeeep dive on the perf and BPF APIs, may be of interest.

The possibly-incorrect impression I get of the performance-analysis related areas of the kernel is that they're a bit siloed (in the same way that X11 is siloed, and only a very small group of people look at it), which may render it bit functionally academic. (It's newer code, though, so there's less chance of eccentricity, FWIW.) Isolation does have benefits - with less chaos to keep up with and less bus factor, the code is changing less and the maintainers have more mental bandwidth to post on mailinglists :), so you have more opportunity to get a good understanding of what's going on.

I don't have the same low-level experience you do, but I do share the same interest in wanting to understand "what's really going on" - and I incidentally want to make a Linux system monitor tool that vacuums up as much information that the kernel is willing to make available to it. `htop` and friends surface a very caricatured picture from maybe 1-10% of the data the kernel has to offer at any given moment.