COMPARE CPU SCHEDULING IN LINUX AND UNIX
TERM PAPER OF OPERATING SYSTEM
[ In the below project there is the explanation of the process algorithms used in UNIX and LINUX and there comparison..]
2.Introduction to unix
3.Unix scheduling algorithms
4.Problems in Unix scheduling
5.Introduction to linux
6.Linux process scheduling
I wish to express my deepest gratitude and warmest appreciation to the following people, who, in any way have contributed and inspired me to the overall success of the undertaking term paper: KAVITA CHOUDHARY MADAM who had assigned me this job to enhance my knowledge, my parents who had been the continuous source of financial aid and moral support and then my roommates who helped me to complete my work on time.
1.WHAT IS PROCESS SCHEDULING?
To manage all the processes in ready queue for the maximum utilization of CPU, this job is done by process scheduler on the basis of scheduling algorithms. Scheduling is a key concept in computer multitasking, multiprocessing operating system and real-time operating system designs. Scheduling refers to the way processes are assigned to run on the available CPUs, since there are typically many more processes running than there are available CPUs. This assignment is carried out by softwares known as a scheduler and dispatcher.
2.WHAT IS PROCESS SCHEDULER?
It takes the job from the ready queue and dispatch it to CPU according to scheduling algorithms Scheduler is mainly concerned with:
a)CPU utilization - to keep the CPU as busy as possible.
b)Throughput - number of processes that complete their execution per time unit. c)Turnaround - total time between submission of a process and its completion. d)Waiting time - amount of time a process has been waiting in the ready queue. e)Response time - amount of time it takes from when a request was submitted until the first response is produced. f)Fairness - Equal CPU time to each thread.
3.WHAT IS SCHEDULING ALGORITHMS?
These are the sum of instructions or system calls the are followed by scheduler to take job to CPU. TYPES OF SCHDULING ALGORITHMS:
Primitive: these are those jobs in which we can take CPU back from the running process and reassign it after some time. Primitive algos:
c.Shortest remaining time
Non-Primitive : these are those jobs in which we can’t take CPU back from the running process. Non-Primitive algos:
a.First come First serve
c.Shortest job first
INTRODUCTION ABOUT UNIX
Unix (officially trademarked as UNIX, sometimes also written as UNIX with small caps) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna. Today's Unix systems are split into various branches, developed over time by AT&T as well as various commercial vendors and non-profit organizations. The Open Group, an industry standards consortium, owns the “Unix” trademark. Only systems fully compliant with and certified according to the Single UNIX Specification are qualified to use the trademark; others might be called "Unix system-like" or "Unix-like" (though the Open Group disapproves of this term). However, the term "Unix" is often used informally to denote any operating system that closely resembles the trademarked system.During the late 1970s and early 1980s, the influence of Unix in academic circles led to...