CIS 3110 Lecture Notes - Lecture 11: Cpu-Bound, Time-Sharing, Transaction Processing
2 Mar 2018
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Document Summary
Scheduling is a matter of managing queues to minimize queueing delay and to optimize performance in a queuing environment. Process execution is characterized by the length of cpu burst and the number of bursts. A process spends waiting in the ready queue. Number of jobs processed per unit of time. Same time/cost regardless of load on the system. The scheduler always chooses a process of higher priority over one of lower priority. Pure priority scheduling may result in starvation of lower-priority processes. If unacceptable, priority of a process could change with its age or execution history. Non-preemptive scheduling takes place due to i/o or process termination. Preemptive scheduling takes allows the os to interrupt the currently running process and move it in ready state. Provides better service to the total population of processes. May prevent one process from monopolizing the processor. User productivity increases with more rapid response time. User time is the time spent thinking about the response.
