Memory management

Question

The address sequence generated by tracing a particular program executing in a pure demand paging system with 100 records per page with 1 free main memory frame is recorded as follows.What is the number of page faults ?

780,450,456,520,599,098,108,109,754,555

Comments

Is it 6?

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No.Even even my answer is 6.

But the correct answer given is 7 page faults.

Answer 1

There are 100 records per page.

Records      Page number

0-99                    0

100-199              1

200-299             2

300-399             3

400-499             4

500-599             5

600-699             6

700-799             7

So, the page sequence or the reference string is 7 4 4 5 5 0 1 1 7 5 and there is only frame in main memory.

7  4   4  5   5  0   1  1   7  5

F  F  H  F H  F  F H  F F

So, in all we have 7 page faults.

Comments

Thank you.:-)