调度机制对CPU-MEM负载共享系统的性能影响

分布式系统中调度机制对负载共享系统性能有不同的影响.基于CPU-MEM的负载共享策略由于充分考虑了分布式系统中内存资源对系统性能的作用,从而大大降低了系统页失效的次数,提高了系统资源的利用率,最终使得整个分布式系统性能有了很大提高.在一般调度策略RR的基础上,基于CPU-MEM的负载共享,提出了一种节点调度策略--多内存多时间片轮询策略(RR-MMMCS),并在模拟实验中表明了RR-MMMCS策略的优越性.讨论了任务的内存需求量和任务服务时间的变异特性对CPU-MEM负载共享策略以及RR-MMMCS调度机制策略性能的影响,表明无论是对计算密集型任务还是数据密集型任务,基于CPU-MEM负载共享策略和RR-MMMCS调度机制策略有较高的效率和稳定的性能.

Effect of scheduling discipline on load sharing system

Scheduling schemes have different effects on the performance of load sharing in distributed systems.Because the load sharing policy based on CPU-memory has made the system memory an important role in effecting the system performance,it can reduce the paging fault and enhance the usage of the system resources,thus can improve the whole performance a lot.In light of the characteristics of the load sharing based on the CPU-memory,a new CPU local scheduling policy named more memory-request more CPU slice(RR-MMMCS),which is based on the round robin policy,is developed.And the merits of RR-MMMCS are proved in the trace-driven simu-lation experiments.Furthermore,the effects on the load sharing policy based on the CPU-memory of the variance of the interarrival time and service time are discussed,and show that the load sharing policy based on the CPU-memory and the RR-MMMCS scheduling policy are effective and have steady performances in both the CPU-bound and the memory-bound jobs.