Improving GPOS real-time responsiveness using vCPU migration in an embedded multicore virtualization platform

In this paper, a vCPU (virtual CPU) migration mechanism in order to improve real-time responsiveness in a GPOS (General Purpose Operating System) is presented in the embedded multicore virtualization platform and can also be applied to CPS environment. In a GPOS/RTOS (Real Time Operating System) virtualization system nowadays, tasks in GPOS, however, also need some degree of real-time services from the system. Unfortunately, in a traditional virtualization platform, a virtualization layer always gives RTOS vCPU higher priority and preempts the execution of GPOS. Therefore, a kernel module in the GPOS is added in our virtualization system to export and boost a GPOS vCPU contexts which needs higher priority against RTOS vCPU. At the same time, in order not to sacrifice the performance of the victim RTOS vCPU, a vCPU migration mechanism is added to our virtualization system, and migrates the RTOS vCPU to a low-loading CPU when this vCPU is preempted. Performance improvement of GPOS's real-time responsiveness is also given while a detailed analysis of the overhead of the RTOS vCPU is performed as well.