Scheduling preemption

Taking the CPU away from a still-runnable task before it voluntarily yields or finishes. Round-robin scheduling uses scheduling preemption when a scheduling quantum expires, commonly using a timer interrupt to regain control. Kernel preemption is the more specific question of whether an execution already within the operating-system kernel can be suspended for another runnable context.

A process scheduling policy that can replace a running, still-runnable task with another task. Time-sliced round-robin scheduling uses a hardware timer interrupt to regain control when a scheduling quantum expires.