Sunday, June 3, 2007

Question 36

Three jobs, A through C, are started simultaneously according to the following scheduling methods: About how many minutes will elapse before Job B execution terminates?

The amounts of processing time for these jobs when executed independently are as follows: Job A takes 5 minutes, Job B 10 minutes, and Job C 15 minutes. The amounts of processing time given are all in terms of CPU time.

[Scheduling Methods]
(1) Jobs are executed in the order they are placed on the queue.
(2) If processing does not end during a specified interval of time (this is called a "time quantum"), processing is suspended, and that job is replaced at the end of the queue.
(3) The time quantum is set to a sufficiently small value compared to job processing time and the time required to switch jobs can be ignored.

a) 15
b) 20
c) 25
d) 30


No comments: