[$] Improving the kernel timers API

The kernel's timer interface has been around for a long time, and its APIshows it. Beyond a lack of conformance with current in-kernel interfacepatterns, the timer API is not as efficient as it could be and stands inthe way of ongoing kernel-hardening efforts. A late addition to the 4.14 kernel paves the way toward awholesale change of this API to address these problems.