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(Ch. 6) In a system using dynamic partitions the Primary Memory use is as shown

ID: 3594056 • Letter: #

Question

(Ch. 6) In a system using dynamic partitions the Primary Memory use is as shown below just before Job Q requests 25K of memory space. a. If First fit memory allocation is being used, i. What change would be made to Primary Memory Use when job Q is loaded? Indicate with the starting point of job Q and ii. the amount of external fragmentation remaining when job Q is loaded (in Kbytes) b. If Best Fit memory allocation were being used, i. what change would be made to Primary Memory Use when job Q is loaded? Indicate with the starting point of job Q and ii. the amount of external fragmentation remaining following the end of job Q (in Kbytes).

2. (Ch. 6) In a system using dynamic partitions the Primary Memory use is as shown below just before Job Q requests 25K of memory space. a. If First fit memory allocation is being used, What change would be made to Primary Memory Use when job Q is loaded? Indicate with the starting point of job Q and the amount of external fragmentation remaining when job Q is loaded (in Kbytes) i. ii. b. If Best Fit memory allocation were being used, i. what change would be made to Primary Memory Use when job Q is loaded? Indicate with the starting point of job Q and the amount of external fragmentation remaining following the end of job Q (in kbytes) ii. Primary memory First Fit Primary Memory Best Fit Operating System Operating System ob P 20K 20K Job P SOK 50K 60K 60K Job N 100K 100K 140K ob O 150K 150K 180K Job L ob L 200K 200K

Explanation / Answer

2. Job Q = 25K

a) First Fit

Operating System 0 20K  

Job P 50k

Job L

200K

Total External Fragmentation = 10 + 30 = 40KBytes

a) Best Fit

Operating System 0 20K  

Job P 50k

Job Q 175K

5 k internal Fragmentation

Job L

200K

Total External Fragmentation = 10 + 40 = 50 K

Operating System 0 20K  

Job P 50k

10k 60K Job N 100K Job Q 125 K 15k internal fragmentation 140 K Job O 150K 30k 180K

Job L

200K