The new profiler popup has a new overhead mechanism which is much lighter, with only a few different levels of overhead. This bug tracks the work to compute it on both the popup and on the about:profiling page.

While we're at it, we should also increase the overhead for Windows sampling times.

See: https://github.com/firefox-devtools/Gecko-Profiler-Addon/issues/83

Markus wrote:

Drastically increase displayed overhead when going below 1ms on Windows
On Windows we now use a busy-loop to implement sub-1ms waits. This loop eats one core per profiled process and has very high overhead. We should reflect that overhead in the UI.