Study on a New Kind of Real-Time Scheduling Algorithm

Many application specific operating systems based on system on chip are composed of lots of tasks that can generate multi-tasking under preemptive scheduling.Preemptive multi-tasking incurs high preemption switching overheads,and these costs may jeopardize a system schedulability.A novel scheduling,named dynamic preemption threshold,is proposed here.The scheduling can reduce preemption costs by thread assignment and changing task dynamic preemption threshold at run time.Because dynamic preemption threshold is based on dynamic algorithm,it can achieve a high processor utilization with relative low cost in context switching and memory requirement.The scheduling perfectly integrates preemption threshold scheduling into EDF algorithm,and accomplishes to transform static model to dynamic algorithm seamlessly.