[crabbone]

> Maybe EBPF is in that vein?

Not just that :) It was "inspired by". Well, it's the same idea.

> The notion of "pausing" the system to step through things interactively was usually untenable.

That's not what EBPF would be used for in such a system. You'd write a bit of code that can be loaded into a running program and executed as a particular condition occurs. Like how you can attach some code to evaluate on a breakpoint in many other debuggers.