Ah, cool. I just tested it out and it seems to work as documented. Unfortunately it requires root access, and incurs about 1 microsecond of overhead per function call on my machine.

Reading the X-Ray abstract, unless I'm missing it, it doesn't go into detail about the time overhead. I do see mention of CPU and RAM usage, though.

I'm not sure that we have any evidence that X-Ray offers less overhead here, though it's certainly cool if it does.

Can you give an example where perf works with 10 million+ probe points?

:)

(and where this does not have an antagonist effect on the other things on the machine?)