Describe Priority Scheduling algorithm of operating system?, Basic Computer Science

Priority Scheduling

• The fundamental idea is straightforward: each process is assigned a priority, and priority is permitted to run. Equal-Priority processes are scheduled in FCFS order. The shortest-Job-First (SJF) algorithm is a special case of general priority scheduling algorithm.
• Priority can be defined either internally or outwardly. Internally distinct priorities use some measurable quantities or behaviors to compute priority of a process.
• An SJF algorithm is simply a priority algorithm where the priority is the inverse of the (predicted) next CPU burst. That is, the longer the CPU explodes, the lower the priority and vice versa.
Illustrations of Internal priorities are
• Deadlines.
• Memory necessities.
• CPU Vs I/O necessities.
• File necessities,
for example, number of open files.
Externally distinct priorities are set by criteria that are external to operating system for example:
• The significance of process.
• Kind or amount of funds being rewarded for computer use.
• The division sponsoring the work.
• A preemptive priority algorithm will preemptive the CPU if the priority of the newly arrival process is higher than the priority of the currently running process.
• This scheduling can be either preemptive or non preemptive
• A non-preemptive priority algorithm will simply put the new process at the head of the ready queue.
A major trouble with priority scheduling is indefinite blocking or starvation. A solution to the trouble of indefinite blockage of the low-priority process is aging. Aging is a method of gradually increasing the priority of processes that wait in the system for an extended period of time.
Posted Date: 5/2/2012 8:39:06 AM | Location : United States







Related Discussions:- Describe Priority Scheduling algorithm of operating system?, Assignment Help, Ask Question on Describe Priority Scheduling algorithm of operating system?, Get Answer, Expert's Help, Describe Priority Scheduling algorithm of operating system? Discussions

Write discussion on Describe Priority Scheduling algorithm of operating system?
Your posts are moderated
Related Questions
For a processor to be able to process an instruction, it requires to be able to determine what the instruction is asking to be carried out. For this to take place, the CPU requires

write a function named "location_of_largest"that takes as its arguments the following:(1) an array of integer values

7. Name and explain the action in Conceptual Dependency which refers to a transfer of possession.

Read World Population Data File. Store the values in multiple vectors. Sort them by most populated region and output the results ext file is here : please">http://www.csupomona.

Development of Personnel Computer Operating System: The next important breakthrough in computer use occurred in 1982, with the introduction of the IBM personal computer. The I

Communications Programs : By communications programs, we mean those programs which allow a computer to communicate via a transmission cable to another electronic device. Here we d

In view of the fact that processes frequently need to communicate with other processes therefore, there is require for a well-structured interaction, devoid of using interrupts, a

What is virtual memory? How address mapping is done in cache memory? Elaborate your answer with examples.

Computer Storage: Computer systems include two types of digital information storage: internal storage, within the CPU, and the backing (back up) storage on external devices su