本文選題：虛擬化 + 虛擬機調度��； 參考：《蘭州交通大學》2013年碩士論文

【摘要】：隨著虛擬化技術不斷成熟，處理器性能不斷提高，這使得多個操作系統(tǒng)同時運行在單個計算機，甚至單個處理器核上成為可能。虛擬化技術已經(jīng)廣泛應用于服務整合和高性能計算領域。在虛擬化環(huán)境中，虛擬機監(jiān)視器(Virtual Machine Monitor，簡稱VMM)接管了傳統(tǒng)操作系統(tǒng)的大部分功能，運行在處理器最高特權級。VMM能夠創(chuàng)建多個隔離的虛擬系統(tǒng)，即虛擬機(Virtual Machine，簡稱VM)，運行在虛擬機中的操作系統(tǒng)稱為客戶操作系統(tǒng)(Guest OS)。其中VMM在虛擬化平臺的資源管理中發(fā)揮重要作用，它根據(jù)調度策略將虛擬機的虛擬CPU動態(tài)映射到物理CPU。 計算性能是衡量計算機系統(tǒng)優(yōu)劣的一個重要指標。由于虛擬化技術目前還不成熟，虛擬化計算平臺的性能與傳統(tǒng)計算平臺相比存在較大的差異，主要體現(xiàn)在系統(tǒng)性能上。虛擬化平臺需要高效調度多個專用的虛擬機“同時”運行在同一物理主機上。VMM中的虛擬機調度算法是影響虛擬化平臺計算性能的關鍵因素。因此，本文研究的重點是如何通過改進虛擬機調度算法來實現(xiàn)虛擬化中計算性能優(yōu)化。具體研究內容是在深入分析Xen虛擬化中Credit調度算法基礎上，提出了共享CPU的虛擬機調度算法。 CPU在傳統(tǒng)環(huán)境中為一個操作系統(tǒng)獨享，而在虛擬化環(huán)境中可能被多個運行客戶操作系統(tǒng)的虛擬機共享。共享CPU的虛擬機表示多個虛擬機同時運行在一個處理器或一個處理器核上，是虛擬化中的一種常見現(xiàn)象。工業(yè)界廣泛使用的Xen虛擬化系統(tǒng)默認使用Credit調度器，隨著共享CPU的虛擬機增加，每個虛擬機經(jīng)歷的CPU訪問延遲隨之延長，這導致I/O受限型應用經(jīng)歷更長的I/O處理延遲，即在共享CPU的虛擬機系統(tǒng)中I/O受限型應用性能很低。 為了提高共享CPU虛擬機系統(tǒng)中I/O受限型應用性能，本文引入了一個新虛擬機類型，稱為延遲敏感型虛擬機，該虛擬機高效運行I/O受限型應用的同時，保持和其它共享CPU虛擬機對資源的公平共享；提出了vCredit調度器，用更小的微時間片調度延遲敏感型虛擬機，而用Credit默認時間片調度非延遲敏感型虛擬機，，能以更高的頻率調度每個延遲敏感型虛擬機，從而延遲敏感型虛擬機能更及時處理I/O事件，同時不破壞所有共享虛擬機的CPU共享公平性；在Xen VMM中實現(xiàn)了vCredit原型。實驗表明，vCredit調度器繼承了Credit調度器在對稱多處理器系統(tǒng)中負載均衡的特性，保留了其公平性的優(yōu)點，同時大大減少網(wǎng)絡數(shù)據(jù)包往返延遲和UDP數(shù)據(jù)報抖動率，達到更好的應用性能。vCredit將Intel的MPI基準測試程序的執(zhí)行時間減少一半或更多。
[Abstract]:With the maturity of virtualization technology and the improvement of processor performance, it is possible for multiple operating systems to run on a single computer or even on a single processor core at the same time. Virtualization technology has been widely used in service integration and high performance computing. In a virtualized environment, Virtual Machine Monitor (VMMs) takes over most of the functions of traditional operating systems, running at the processor's highest privilege level. VMM can create multiple isolated virtual systems. The operating system running in the virtual machine is called guest operating system Guest OS. VMM plays an important role in resource management of virtualization platform. It dynamically maps virtual CPU of virtual machine to physical CPU according to scheduling strategy. Computing performance is an important index to measure the quality of computer system. Because the virtualization technology is not mature at present, the performance of the virtualization computing platform is different from the traditional computing platform, which is mainly reflected in the system performance. Virtualization platform requires efficient scheduling of multiple dedicated virtual machines "simultaneously" running on the same physical host. VMM scheduling algorithm is the key factor that affects the computing performance of the virtualization platform. Therefore, this paper focuses on how to optimize computing performance in virtualization by improving the virtual machine scheduling algorithm. On the basis of deep analysis of Credit scheduling algorithm in Xen virtualization, a virtual machine scheduling algorithm based on shared CPU is proposed. CPU is exclusive to an operating system in traditional environment. In a virtualized environment, it may be shared by multiple virtual machines running client operating systems. It is a common phenomenon in virtualization that shared CPU virtual machines mean that multiple virtual machines run on one processor or one processor core at the same time. Xen virtualization systems, which are widely used in industry, use Credit scheduler by default. As the number of shared CPUs increases, the CPU access latency for each virtual machine increases, which results in longer I / O processing latency for I / O restricted applications. That is, the performance of I / O constrained applications in shared CPU virtual machine systems is very low. In order to improve the performance of I / O restricted application in shared CPU virtual machine system, a new type of virtual machine called delay sensitive virtual machine is introduced in this paper. A vCredit scheduler is proposed to schedule the delay sensitive virtual machine with a smaller time slice, while the non-delay sensitive virtual machine is scheduled by the default time slice of Credit. Each delay-sensitive virtual machine can be scheduled at a higher frequency, so that the delay-sensitive virtual machine can handle I / O events more timely without destroying the CPU sharing fairness of all shared virtual machines, and the vCredit prototype is implemented in Xen VMM. The experimental results show that the credit scheduler inherits the load balancing property of the credit scheduler in symmetric multiprocessor systems and retains the advantages of fairness, while greatly reducing the network packet round trip delay and the UDP Datagram jitter rate. Achieve better application performance. VCredit halves or more execution time for Intel's MPI benchmark.
【學位授予單位】：蘭州交通大學
【學位級別】：碩士
【學位授予年份】：2013
【分類號】：TP302

【共引文獻】

相關期刊論文 前1條

1 喻波;胡懷湘;;MR-IOV:下一代數(shù)據(jù)中心I/O虛擬化技術[J];計算機技術與發(fā)展;2013年10期

本文編號：2031058