In batch operating system three job J1 J2 and J3 are submitted for execution each job involes an I/O activity a CPU time and another i/o activity job a requires a total of 20 ms with 2 ms CPU time J2 requires 30 ms total time with 6 ms CPU time J3 requires15 ms total time 3 ms CPU time what will be the CPU utilization for uniprogramming and multiprogramming

(A) The CPU time for J1 is = 2 ms other time is = 18 ms, for J2 CPU time = 6 ms other time = 24 ms, for J3 CPU time = 3 ms and other time = 12 ms (B) The CPU Utilization for uni-programming is 0.203 or 20.3% (C) For Multi-programming, when a program is not free and busy with an operation, the CPU is allocated to other programs.

Explanation:

Solution

Given that:

A (1) Job J1 = CPU time = 2ms

Other time = 18 ms

Total time = 20 ms

(2) Job J2 = CPU time 6ms

Other time = 24 ms

Total time = 30 ms

(3) Job J3 = CPU time = 3ms

Other time = 12ms

Total time = 15 ms

(B) For the CPU Utilization for uni-programming, we have the following as follows:

CPU utilization = The total time of CPU/The total real time

Thus,

= (2 + 6+3) / (18+24+12)

= 11/54

=0.203 or 20.3%

(C) For the CPU utilization for multi-programming, when a program is not available that is busy in an operation, such as the input and output the CPU can be allocated or designated to other programs