开放式实时系统中的自适应调度方法  

The Adaptive Scheduling Approaches to Open Real-Time Systems

作　　者：邹勇[1] 淮晓永[1] 李明树[1] 

机构地区：[1]中国科学院软件研究所互联网软件技术实验室,北京100080

出　　处：《计算机学报》2004年第1期58-65,共8页Chinese Journal of Computers

基　　金：国家自然科学基金重大项目 (698962 5 0 3 );国家"八六三"高技术研究发展计划(2 0 01AA113 2 0 1)资助

摘　　要：首先针对开放式实时系统 ,讨论了自适应实时调度的需求情况和自适应技术应用上的关键问题 ;提出了适用于硬实时调度需求的调度参数自适应调整机制 ;重点面向软实时调度需求 ,提出了一种基于模糊控制策略的自适应调度方法 ,它致力于动态跟踪调度对象的负载变化 ,并把截止期错过率控制在期望值附近 .相对于现有方法 。The adaptive scheduling problems for open real time systems are discussed in this paper. In an open real time system, tasks are loaded dynamically and their schedulability is tested on line. At the mean time, how much CPU bandwidth the tasks need may not be known as a priori. This feature urges us to develop adaptive real time scheduling approaches which can allocate resources to tasks dynamically at run time. According to the scheduling requirements of the open real time system, adaptive scheduling approaches are presented respectively for hard real time tasks and soft real time tasks. Firstly, an approach based on feedback control is presented for the hard real time tasks scheduling. Secondly, for soft real time applications, another adaptive scheduling approach is presented. The second one is based on fussy control technology. It can control the deadline missing ratio near the expected value while sampling the applications’ performance. These adaptive scheduling approaches are developed for open real time system, with the merits that they can schedule different kinds of real time tasks and adapt to their dynamic resource requirements through tuning the schedulers.

关 键 词：开放式实时系统 自适应调度方法 调度策略 服务器 操作系统 

分 类 号：TP316.2[自动化与计算机技术—计算机软件与理论]