Abstract: In garbage collection(GC) models of previous work, real-time tasks and GC are mostly scheduled by rate-monotonic （RM) algorithm for simplicity. To meet the deadlines of hard real-time tasks, the time-based GC is proposed in recent years. The mutators and GC are scheduled with earliest deadline first (EDF), the latency and jitter of EDF and RM scheduling are compared, and the detail analysis of scheduling GC by EDF is given. The simulation results are given too. The comparison results show that EDF scheduled systems can be more portable since they can schedule aperiodic tasks with hard real-time requirements and the system memory requirements can be further reduced as compared with other scheduling strategies based on RM algorithm. Furthermore, in EDF scheduled system the performance of latency and jitter of tasks are not worse than those in RM scheduled system.

Key words: GC, real-time, algorithm, memory requirements, EDF scheduling