Were not getting any younger

The Linux time subsystem, which once provided only tick granularity via a simple periodic addition to xtime, now must provide nanosecond resolution. As more and more unique timekeeping hardware becomes available, and as virtualization and low-latency demands grow, the complexity of maintenance and bug resolution increases.

This paper explores the requirements of a modern timing system, encompassing both time-keeping and hard and soft timers. We propose a new infrastructure to elegantly meet those needs and discuss how kernel interfaces can best be modified to use human-time units.