Q40,p2,D14. In a demand paging memory system, page table is held in registers. The time taken to service a page fault is 8 m.sec. if an empty frame is available or if the replaced page is not modified, and it takes 20 m.secs., if the replaced page is modified. What is the average access time to service a page fault assuming that the page to be replaced is modified 70% of the time ?

(A) 11.6 m.sec. (B) 16.4 m.sec.

(C) 28 m.sec. (D) 14 m.sec

Answer B.

Explanation.

Let 30 faults are without modification so time is 240 ms.

And rest 70 faults are with medication 20x70 ms

Average access time of servicing a page fault is (240+1400)/100.