A Modified Priority Based CPU Scheduling Scheme for Virtualized Environment

In order to maximum the hardware resource utilization, Virtual Machine (VM) management has become an important research field of virtualization technology. VM scheduling is crucial for the throughput of a system and thus affects the overall system performance. According to the scheduling algorithm of Credit Scheduler using in XEN hypervisor, each virtual CPU is asynchronously assigned to a physical CPU by CPU scheduler in order to maximize the throughput. But for a concurrent program, the implementations of threads are not completely independent. In this paper, a solution is proposed for the synchronization problem of a concurrent program. By modifying the Xen Credit Scheduler, threads in the concurrent program can be synchronized and the performance in concurrent workload is greatly enhanced. The waste of CPU time can be reduced and achieve higher throughput while keeping the design of the scheduler to be light weight, fair, and efficient. With the proposed scheduler, more VMs can be deployed while achieving the same throughput, thus gain greater utilization of resources and better energy efficiency