An Improved Least-Laxity-First Scheduling Algorithm of Variable Time Slice for Periodic Tasks

The LLF (least laxity first) scheduling algorithm assigns a priority to a task according to its executing urgency. The smaller the laxity value of a task is, the sooner it needs to be executed. However it leads to switch frequently among tasks, which causes the overhead of a system and restricts its application. The least switch and laxity first scheduling algorithm is proposed in the paper, which improves the least laxity first algorithm for periodic task by searching out an appropriate common divisor.