Adaptive Interrupt-free System In High Performance I/O Virtualization

Along with the development of cloud computing and virtualizationtechnology, high speed network connection becomes one of the keycomponents in cloud computing and datacenter. Single-root I/Ovirtualization (SR-IOV) enhances the network throughput be close to linerate and achieve high scalability in the10Gbps and higher networkenvironment. However, the overhead of the interrupt virtualization withSR-IOV technology still remains a significant overhead source due toadditional trap-and-emulation overhead on the virtual interrupt controller.The higher the virtualization network connection is, the higher interruptfrequency is generated by the high bandwidth network. To mitigate thisproblem, we propose a simple event-based polling model, EBP, whichleverages existing system events to trigger a regular packet polling so thatnetwork interrupt is eliminated from the critical I/O paths in the virtualenvironment.. Due to the varieties of system events, the EBP can deal withthe network workload in a configurable and flexible manner. Based onhierarchical virtualized environment, EBP can also be implemented in eitherguest OS kernel level or VMM level. Since the polling is much morelight-weight than the interrupt processing, EBP can significantly reduce thenetwork processing overhead. The experimental results prove the efficiencyof EBP, which can achieve up to59%performance improvement and23%better scalability ratio.