With the rapid progress of information and networking technologies, the development of embedded systems becomes the highlight around the all of IT industries. In this situation, Linux system, which has made great success in server applications, will obtain further development and find wide applications in the embedded industry, with the advantages of open codes, low cost and powerful functions etc. The research on embedded Linux systems has recently been paid many attentions to and becomes very popular.The paper mainly discusses the research of Linux real time performance in order to meet the needs in embedded field. Firstly, the paper introduces embedded system, real time operation system, embedded Linux, deeply analyses advantages of Linux serving as embedded operation system and shortcomings in the aspect of hard real time performance. The paper compares various scheme of embedded Linux implementing real time performance on the basis of above. We focus on the kernel preemption strategy and scheduling algorithms.This article compares the advantages and disadvantages of two improved schemes for kernel preemption, and analyzes the real time shortcomings of Linux process schedule scheme, and discusses the real time process schedule schemes of RM & EDF, and how to resolve the problem of PRI inversion. We design and realize a real time scheduler based on EDF idea. After some tests, we prove that the new real time scheduler has better effect in real time performance than unimproved Linux, and the new one can be well used in real time field.At last, some other key techniques of Linux real-time method and opinions are put forward. Through changing corresponding method, it must be made a large effect on embedded domain. We view the direction of embedded Linux in the future. |