Abstract: The development of complex real-time embedded systems has become a trend in recent years.To reduce cost and enhance flexibility,multiple systems are sharing common computing platforms via virtualization technology.We studied the real-time performance of algorithm Credit in Xen which is the most popular virtual machine monitor.Firstly we analyzed the basic implementation of Credit which is the default scheduling algorithm in Xen virtual machine.Then we proposed and proved an effective method that can configure VCPU parameters to improve the real-time performance of Credit for promotion.On this basis,we finally obtained the resources function curve SBF allocated for VCPU in the worst case by showing and getting the basic properties of Credit scheduling algorithm.

Key words: Virtualization,Xen,Scheduling algorithms,Real-time systems,Supply bound function