::scalehrtime could be more precise
Work by Bryan Cantrill.
Original comment by Bryan says:
For quite some time, we've had the ::scalehrtime dcmd (see OS-770). However, this is imprecise with respect to large values (e.g., TSC reads) because it doesn't follow the same algorithm as the kernel (which only converts values less than the tsc_tick interval). ::scalehrtime should mimic this, using a delta against tsc_last if the value to convert is closer to tsc_last than it is to 0.