Question

Consider the following set of jobs to be scheduled for execution on a single CPU system.

Job	Arrival Time	Burst (msec)	Priority
A	0	6	3 (Silver)
B	1	2	1 (Diamond)
C	3	5	3 (Silver)
D	5	3	4 (Bronze)
E	7	2	2 (Gold)

  

(a)     Draw a Gantt chart showing First-Come-First-Served (FCFS) scheduling , Premtive PRIORITY Sheduling, Highest Response ratio Next (HRRN) and Round Robin(quantum=4).

I need this in half hour

Answer 1

Gantt Charts

1.FCFS

A

B

C

D

E

0-------------------6---------------------8----------------------13---------------------16------------------18

2. Preemptive Priority

A

B

A

E

A

C

D

0-------------2-------------4---------------7--------------9--------------10--------------15-------------18

3. Highest Response Ratio Next(HRRN)

Response ratio = (waiting time + service time)/service time

Upto 7 all jobs are arrived so A and B execute. ( Non preemtive)

RR(C) = (5+3)/5 = 1.6

RR(D)= (3+5)/3 = 8/3 = 2.6

RR(E) = (7+2)/2 = 9/2 = 4.5

A

B

E

D

C

0-------------------6---------------------8-------------------10---------------------13--------------------18

4. Round Robin(quantum = 4)

A

B

C

D

E

A

C

0-------------4--------------6---------------10-------------13------------15-------------17--------------18

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