Linux: ktimers, High Resolution Timer Framework

With the latest release of his real time kernel patches [story], Ingo Molnar [interview] announced a new feature, "a complete rework of the high-resolution timers framework, from Thomas Gleixner, called 'ktimers'." Ingo explains that the end-effect of the new timer framework is a "much more deterministic HRT engine." He goes on to explain how this works:

"Under the ktimer framework the HR (and posix) timers live in a separate domain, have their own (per-CPU) rbtree to stay scalable and deterministic even with a high number of timers. Another positive effect of the introduction of separate ktimers is that kernel/timer.c is now using preemptible locks again, removing the cascade() worst-case latency. The cleanup factor is high as well: the ktimer framework slashes 1300+ lines off the HRT code. See kernel/ktimer.c for details."