【作者】 张莹；

【导师】 郑志蕴；

【作者基本信息】 郑州大学 ， 计算机应用技术， 2012， 硕士

【摘要】 虚拟化技术是创建灵活动态的企业级设施架构的关键机制。随着多处理器技术的发展,计算能力有了很大提高,也加速了虚拟化技术这一关键机制的发展。虚拟化技术可以屏蔽底层复杂的物理环境,允许多个虚拟机之间共享物理机资源,另外,正在运行的虚拟机可以无间断地在两台物理机之间进行迁移。所以对于大多数企业来说,基于虚拟化技术的企业架构能够提供更多的安全稳定性能,并且也是合并服务器资源和应用的理想解决方案之一。Xen是目前应用比较广泛的开源虚拟化软件之一,它能够使多个客户操作系统以接近物理系统的性能同时运行在相互隔离的环境中,并对底层物理硬件实现共享访问,包括处理器资源。在虚拟化环境中,虚拟机上的CPU调度是以虚拟CPU作为调度单位进行分时调度。SEDF是Xen中缺省的CPU调度算法之一,该算法支持实时性较强的应用,但是缺少SMP架构中多处理器之间负载均衡的控制。本文考虑到SMP架构中处理器和cache的关系,提出一种虚拟机环境中的CPU调度算法,该算法设计了一个共享等待队列,各个处理器根据自身负载情况,共享等待队列动态调整VCPU的调度顺序,不仅能够选择最优处理器来执行,并且可以避免处理器空闲。仿真测试结果表明,本文提出的调度算法具有较高的系统吞吐量和任务完成率,也能够降低任务执行的平均周转时间和平均响应时间。本文提出的算法不仅减少了cache和内存数据同步带来的性能损耗,而且支持较好的全局负载均衡,能够充分合理利用处理器资源。更多还原

【Abstract】 Virtualization is a key mechanism of creating a flexible and dynamic enterprise infrastructure. With the development of more powerful multi-processors, the availability of computing power increased. Also it accelerates the trend of virtualization. It can shield the complicated underlying physical environment easily, and allow sharing of the physical machine resource among different virtual machines. Moreover, virtualization could dynamically migrate virtual machine from the running physical machine to another one without interrupting. So it can provide more security and steady for enterprise infrastructure, and it is also an ideal solution to consolidate server and application for most enterprises.Xen is one of the most popular open source software. It could make several guest OS running with the similar performance in the isolated environment and sharing the physical resource such as processor. In the virtual environment, the CPU scheduling of virtual machine is based on the virtual CPU and is time-shared. SEDF is one of the default CPU schedulers in the Xen. It supports the real time application well, but doesn’t have the ability of balancing the load among multi-processors in the SMP architecture.Considering the relationship between SMP architecture and cache, this paper illustrates a new scheduler. This scheduler contains a share waiting queue, and according to the loading status of each CPU, it dynamically adjusts the scheduling order of the virtual CPU. It can choose a optimal CPU for the scheduling virtual CPU, and avoid the free of processor.The simulation results demonstrate that the improved algorithm could get better performance than SEDF under several test standard. The system throughput and completed tasks are well, and the average turnaround time and average response time are get smaller. The improved algorithm can not only decrease the performance loss of multi-processor, but also support global loading balance better and make the processor resource more fully and reasonable.更多还原