Question # 6 [5 Marks]

1. Assume that the main memory has the following 5 fixed partitions with the following sizes: 100KB, 500KB, 200KB, 300KB and 600KB (in order)

1. Explain the following allocation algorithms: First-fit, Best-fit and Worst-fit.
2. How would each of the First-fit, Best-fit and Worst-fit algorithms place processes of 212KB, 417KB, 112KB and 426KB (in order)?
3. Compute the total memory size that is not used for each algorithm.
4. Which algorithm makes the efficient use of the memory?

2. Consider the following Page tables and show the process allocation in main memory having 19 frame

Process 0			Process 1			process 2			process 3
page #	Frame		Page #	Frame		Page #	Frame		Page #	Frame
0	3		0	0		0	1		0	2
1	4		1	5		1	6		1	11
2	7		2	8		2	13		2	12
3	9					3	15		3	14
4	10					4	16
						5	17
						6	18

Question # 7 [5 Marks]

A disk contains total 200 tracks and Request Queue contains tracks 80, 160, 41, 136, 22, 18, 192. Apply FCFS and SCAN and find total track movements if head start position is at 50. Compare the results and Discuss which algorithm is better to apply?