Linux进程调度机制分析

Analysis on the Mechanism of Linux Process Scheduler

从如何增强Linux操作系统对实时任务的支持出发,阐述了2.4内核进程调度系统设计上存在的缺陷:缺乏对实时任务的支持,无法保证实时任务得到及时响应和调度;对多处理器环境的支持较差.分析了Linux的最新2.6内核进程调度系统的原理和实现细节.与2.4内核相比,2.6内核增强了对实时任务和多处理器环境的支持,实现了O(1)调度算法,支持抢占式调度,在响应时间及系统开销上均有大的改进,其显著特点是支持抢占式调度、支持多处理器负载平衡等,更加适合于实时应用环境.

In order to study how to strengthen the real-time support of Linux operating system, some weaknesses of the process scheduler of the 2.4 kernel are discusses. Owing to the lack of real-time support, the system can not guarantee that the real-time tasks be responded and scheduled in time. The 2.4 kernel is not enough to the multiprocessor support. This paper analyses the principles and implementing details of process scheduler in the 2.6 kernel. Compared with the 2.4 kernel, the 2.6 kernel strengthens the support of real- time tasks and multiprocessor environment, implements the O （1） scheduling algorithm and preeption. The article also describes some improvement in the 2.6 kernel on response time and system spending. The prominence characteristics of the 2.6 process scheduler are to support preemption and the loading balance of multiprocessor etc.,so it can be used in the real-time environment.