but date and clock_gettime are still accessible and not much more overhead than the Mach API call. Additionally as I mention in another comment, this would have

but date and clock_gettime are still accessible and not much more overhead than the Mach API call. Additionally as I mention in another comment, this would have to be about Meltdown, not Spectre, and Meltdown is mitigated in the kernel through other techniques without sacrificing timers.