Eager Scheduling with Lazy Retry for Dynamic Task Scheduling

Task scheduling policies can be generally classiied as eager scheduling and lazy scheduling. The former attempts to schedule the tasks whenever there are free processors available, while the latter delays the scheduling of some tasks so as to accommodate more appropriate tasks. In this paper we propose a hybrid policy, called eager scheduling with lazy retry (ESLR). This policy tries to schedule a task eagerly upon its arrival. If the scheduling fails, then the task is rescheduled after a delay period. This later mechanism is referred to as lazy retry. Simulation results show that the ESLR policy can reduce system fragmentation and enhance scheduling eeciency.