Bootchart but lighter and more precise. - I remember this bootchart Debian project from many years ago?
Relies on ftrace events to monitor everything needed while incurring a very low overhead. It has a microsecond-precision and doesn't affect the workload being measured by more than a few percents.
Screenshots with Perfetto (Google Chrome tracing UI)
It's useful for debugging build systems, understanding what shell scripts actually do, figuring out what programs does a proprietary software run, etc.
Comments from abathur on resholve (built with Oils)
this relies on fragile bash mechanisms; maybe OSH can do better - with profiling there's a bunch of errors but overall it's ~300x slower https://i.imgur.com/qif7Qp3.png so i'm sceptical on all the efficiency claims