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Ebook Operating systems - Internals and design principles (6th edition): Part 2

(BQ) Part 2 book "Operating systems - Internals and design principles" has contents: Uniprocessor scheduling, multiprocessor and real time scheduling, file management, I/O management and disk scheduling, embedded operating systems, embedded operating systems,.and other contents. | PART FOUR Scheduling A n operating system must allocate computer resources among the potentially competing requirements of multiple processes. In the case of the processor, the resource to be allocated is execution time on the processor and the means of allocation is scheduling. The scheduling function must be designed to satisfy a number of objectives, including fairness, lack of starvation of any particular process, efficient use of processor time, and low overhead. In addition, the scheduling function may need to take into account different levels of priority or real-time deadlines for the start or completion of certain processes. Over the years, scheduling has been the focus of intensive research, and many different algorithms have been implemented. Today, the emphasis in scheduling research is on exploiting multiprocessor systems, particularly for multithreaded applications, and real-time scheduling. ROAD MAP FOR PART FOUR Chapter 9 Uniprocessor Scheduling Chapter 9 concerns scheduling on a system with a single processor. In this limited context, it is possible to define and clarify many design issues related to scheduling. Chapter 9 begins with an examination of the three types of processor scheduling: long term, medium term, and short term. The bulk of the chapter focuses on short-term scheduling issues. The various algorithms that have been tried are examined and compared. Chapter 10 Multiprocessor and Real-Time Scheduling Chapter 10 looks at two areas that are the focus of contemporary scheduling research. The presence of multiple processors complicates the scheduling decision and opens up new opportunities. In particular, with multiple processors it is possible simultaneously to schedule for execution multiple threads within the same process. The first part of Chapter 10 provides a survey of multiprocessor and multithreaded scheduling. The remainder of the chapter deals with real-time scheduling. Real-time requirements are the most demanding for a .