Andrew S. Tanenbaum (OS) Edition 4 Exercise 2 Question 40 (Page No. 177)

Question

Round-robin schedulers normally maintain a list of all runnable processes, with each process occurring exactly once in the list. What would happen if a process occurred twice in the list? Can you think of any reason for allowing this?

Answer 1

If a process occurs twice in that list then it would be executed twice by the processor.

The reason for allowing this may be to increase priority of a process as it will be executed as many number of times as it is in the list.

Answer 2

Another reason might be the that other process execution time finished as the process listed twice in the list is the only process that required execution.

Answer 3

A process will gets more quanta per scheduling cycles and also it is used to give important process a larger share of CPU