| 摘要: |
| 任务可调度性判定是实时系统调度理论研究的核心问题.单调速率(RM)算法是实时调度的重要算法,自其提出以来已被广泛研究.然而到目前为止,尚缺乏专题性的文章来系统而深入地探讨RM及其扩展算法的可调度性判定,以及各种现实条件和实现方式(包括任务调度的时间开销和任务同步问题等)对可调度性的影响.围绕RM算法下的可调度性判定问题,由浅入深,系统性地讨论各种不同假设和实现方式对可调度性的影响,具体为下述3大类问题：（1）理想的RM算法下的可调度性判定的CPU利用率最小上界最小及可调度的充分必要条件；（2）考虑调度时间开销情况下的可调度性判定条件；（3）优先级反转协议及其对可调度性的影响.给除了具体实例来叙述上述问题，并从算法复杂度和可检测率两方面比较各种算法的优劣。 |
| 关键词: 实时系统 实时操作系统 实时调度 RM算法 可调度性判定 |
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| 基金项目:Supported bv the National Natural Science Foundation of China under Grant No.60373053(国家自然科学基金);the Hundred Talents of the Chinese Academy of Sciences(中国科学院"百人计划");the Chinese Academy of Sciences and the Royal Society of the United Kingd |
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| On Schedulability Test of Rate Monotonic and Its Extendible Algorithms |
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WANG Yong-Ji,CHEN Qiu-Ping
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| Abstract: |
| Schedulability test is an essential issue in real-time scheduling theory. Rate monotonic(RM) algorithm is one of the scheduling algorithms in real-time systems However, a general review on this field can hardly be seen. This paper presents a review of the various schedulability tests under RM algorithm, starting from the simplest ideal RM scheduling model and then going into the more complicated ones. Three subjects are covered: (1) schedulable tasks?CPU utilization least bound and the sufficient and necessary conditions; (2) condition of schedulable tasks taking the scheduling time cost into account; (3) condition of schedulable tasks taking priority inversion into account. Some appropriate examples are provided to illustrate and compare the relative merits among the discussed algorithms. |
| Key words: real-time system real-time operating system real-time scheduling RM algorithm schedulability test |
