I have a slight concern with using internals like __commpage_gettimeofday, but it has been in the released xnu source since at least 10.12, and it was [used by qemu when they had separate darwin support](https://github.com/qemu/qemu/blob/1c8a881daaca6fe0646a425b0970fb3ad25f6732/d...) way back in 2011, so it was presumably around even for 10.6/10.7. So, given the performance impact, I'm in support.