Can nanoTime be non-monotonic?

[Pavel Rappo]

I was reading a book that refers to this 2015 post claiming that
nanoTime can be non-monotonic:
https://steveloughran.blogspot.com/2015/09/time-on-multi-core-multi-socket-servers.html

In fact, I'm not sure what the claim actually is, as the author is a
bit vague. It's unclear whether they say that they have actually
observed it, or they just strongly suspect that it's possible.

Has non-monotonicity ever been observed by hotspot developers? Can it
be observed on a modern hardware + JVM?

Thanks,
-Pavel