In this dissertation , the hardware / software co - design flow and ac3 decoding algorithm is analyzed and the ac3 audio decoding on the virgo risc - core . then the extended instruction is added to lessen the cpu cycles used and to reduce the memory space used by the decoding program 其次,本文在分析软硬件协同设计流程和ac3解码算法以及risc核virgo上实现ac3音频解码的基础上,扩展指令集增加特殊指令减少了ac3解码的时间和解码程序占用的空间。
Context switching occurs when the operating system scheduler replaces one process operating on a cpu with another process and is the result of a variety of factors , such as job or process priority , waiting for other resources like i o , if the process is using up all of its allocated cpu cycles time slice , and so on 上下文切换是在操作系统调度程序用另一个进程替换cpu上正在运行的一个进程时发生的,而且是各种因素作用的结果,例如作业(或进程)优先级、是否等待其他资源(如i / o ) 、进程是否将用完所有分配给它的cpu周期(时间片)等。
This article first analyzes a paradoxical phenomenon that is predominant in campus lan settings where there is a large amount of idle cpu cycles available while at the same time the computing needs from many researchers ca n ' t be met . it proposes an idea of setting up a campus computing grid with a detailed plan for its implementation , discusses the challenges of upscaling a campus computing grid into an internet computing grid and suggests possible solutions . gram ( grid resource allocation manager ) of globus toolkit 3 . 2 and relative technology on it is studied , and the solutions to extend gram to support task rescheduling and the cooperation type task are proposed . the design and implement of the gram client based on web that is the kernel part of the task anagement module are discussed , and the design of resource discovery module and task transfer module are gived 本文首先分析了校园网环境中存在大量计算资源闲置与科研人员科学计算需要得不到满足之间的矛盾,给出了建立校园计算网格的构想及具体的设计方案,并提出了校园计算网格推广到internet计算网格存在的问题及解决方案;研究了globustoolkit3 . 2中的资源分配管理器gram及其相关技术,并给出了扩展gram对任务再调度和协作型任务支持的解决方案;设计实现了校园计算网格中任务管理模块的核心部分基于web的gram客户端,并介绍了资源发现与任务迁移模块的设计;然后在分析min - min调度算法基础上,借鉴qosguidedmin - min算法的思想,并利用主机资源分类的思想,给出了在负载平衡和时间跨度都有较大改善的balance - qosguidedmin - min算法模型的思想与实现;最后设计实现了调度算法验证模块,并在此模块上对比了改进的算法balance - qosguidedmin - min与min - min算法的调度性能。