UGC NET CSE | December 2014 | Part 2 | Question: 40

Question

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.

Comments

can anyone please tell what is the meaning of “replaced page is modified”.

Answer 1

Service a page fault=8msec.

Page is not modified=20m.sec.

Page replace=70% of time

the average access time to service a page fault=0.7⨉20+0.3⨉8=14+2.4=16.4ms

Comments

srestha...u did wrong..

if an empty frame is available or if the replaced page is not modified = 8 m.secs.,

if the replaced page is modified. = 20 msec

---

yes @Tauhin ,thanks