Embedded Linux Design And Implementation Of Fault-tolerant Real-time Scheduling Algorithm

Applications in embedded Linux operation system is a hot research subjectnowadays. How to change the Linux from normal OS to embedded real-time OS is avery important research issue. How to improve real-time ability and reliability of theembedded Linux operation system is a issue that is full of challenge. Because taskscheduling directly impacts the system performance, to study task scheduling scheme inembedded Linux operation system is of great significance. With the support of thenational 863 project, which arms to construct a platform for embedded software, thisdissertation has deeply studied fault-tolerant scheduling theory in Linux operationsystem.Firstly, the dissertation analyzes the characters of embedded Linux OS, theadvantage and disadvantage are pointed out accordingly. Analyzes the method ofimproving the real-time ability, Introduces a typical embedded real-time LinuxOS—RT-Linux. Analyzes its system construction, modification that arms to hardreal-time performance, and its scheduling algorithm.Secondly, the dissertation discusses the factors that influence the system reliability,the causes of those factors, and the basic concepts of system reliability systematically,introduces real-time scheduling in detail. And then presents two different real-timemulti-processor fault-tolerant scheduling algorithms: PPB-MFT-EDF andAPB-MFT-EDF. The first one is passive backup, while last one is active backup. Thecertification for task schedulable is given and some important character about the twoalgorithms is present. The certification and simulation results have proved that theperformance of APB-MFT-EDF algorithm is better than PPB-MFT-EDF.Thirdly, we achieve the FT-EDF algorithm based on RT-Linux. This dissertationanalyzes the scheduling module of RT-Linux in detail, and presents the modification tothe scheduling module that makes FT-EDF algorithm usable. Some test base on themodified algorithm has been carried out. The results show that the time and performancecost of fault-tolerance scheduling can satisfy requirements of real-time system.