Lecture 3

Question 1

Page Fault

Answer 1

page is not currently loaded into a physical address space

Question 2

What detects page faults?

Answer 2

MMU

Question 3

What does the exception handling for page faults?

Answer 3

OS-kernel level applications

Question 4

How does OS handle page fault?

Answer 4

Tries to make page accessible and map it to physical memory. If page cant be accessed process is terminated and an illegal memory access error thrown.

Question 5

Name the three types of page faults.

Answer 5

compulsory faults, capacity faults, and policy faults.

Question 6

What is the most common type of page fault?

Answer 6

Compulsory fault

Question 7

Compulsory fault

Answer 7

Required page is not in main memory

Question 8

How to avoid a compulsory page fault?

Answer 8

Pre-fetching

Question 9

Pre-fetching

Answer 9

Frequently-used pages are loaded into cache

memory accessible by the page table.

Question 10

Capacity faults

Answer 10

Main memory is full and pages must be swapped out for the required page to be swapped in (page replacement algorithm).

Question 11

Policy fault

Answer 11

Page is prematurely swapped out of main memory because of the replacement policy (algorithm).

Question 12

What carries out the scheduling of page resources?

Answer 12

page replacement policy (an algorithm run by the memory management unit)

Question 13

Fully associative memory mapping

Answer 13

Any page in virtual memory can be translated to any frame in physical excluding frames dedicated to kernel level applications.

Question 14

Page Table Base Register (PTBR)

Answer 14

tells the MMU whether the page is already in memory or not.

Question 15

Translation Lookaside Buffer (TLB)

Answer 15

special memory cache for storing frequently used

pages.

Question 16

When trying to load a page, not in main memory where does the MMU look for the page?

Answer 16

First in TLB then in secondary storage.