Consider a main memory with 3 page frames in the following sequence of page reference 3, 4, 2, 3, 9, 1, 6, 3, 4, 9. What is the number of page fault using FIFO page replacement algorithm?

A virtual memory system uses FIFO page replacement policy and allocates a fixed number of frames to the process. Consider the following statements M : Increasing the number of page frames allocated to a process sometimes increases the page fault rate N : Some programs do not exhibit locality of reference Which one of the following is true?

A

Both M and N are true and N is the reason for M

B

Both M and N are true but N is not the reason for M

C

Both M and N are false

D

M is false, but N is true

A virtual memory system uses First In First Out (FIFO) page replacement policy and allocates a fixed number of frames to a process. Consider the following statements. P : Increasing the number of page frames allocated to a process sometimes increases the page fault rate Q : Some programs do not exhibit locality of reference Which of the following is TRUE?

A

Both P and Q are true, and Q is the reason for P

B

Both P and Q are true, but Q is not the reason for P

C

P is false but Q is true

D

Both P and Q are false

Fact 1: Eyeglass frames cost between $35 and $350.
Fact 2: Some eyeglass frames are made of titanium.
Fact 3: Some eyeglass frames are made of plastic.

If the first three statements are facts, which of the following statements must also be a fact?
I: Titanium eyeglass frames cost more than plastic frames.
II: Expensive eyeglass frames last longer than cheap frames.
III: Only a few eyeglass frames cost less than $35.

A

I only

B

II only

C

II and III only

D

None of the statements is a known fact.

Consider the virtual page reference string 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 Let a computer system has main memory size of 3 page frames which are initially empty and it is running on demand paged virtual memory system. The number of page faults under LRU and FIFO page replacement policy are respectively:

A

9, 6

B

6, 3

C

6, 9

D

3 , 6

Consider the virtual page reference string 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 on a demand paged virtual memory system running on a computer system that has main memory size of 3 page frames which are initially empty. Let LRU, FIFO and OPTIMAL denote the number of page faults under the corresponding page replacement policy. Then

A

OPTIMAL < LRU < FIFO

B

OPTIMAL < FIFO < LRU

C

OPTIMAL = LRU

D

OPTIMAL = FIFO

Recall that Belady’s anomaly is that the page-fault rate may increase as the number of allocated frames increases. Now, consider the following statements: S1: Random page replacement algorithm (where a page chosen at random is replaced) Suffers from Belady’s anomaly S2: LRU page replacement algorithm suffers from Belady’s anomaly Which of the following is CORRECT?

A

S1 is true, S2 is true

B

S1 is true, S2 is false

C

S1 is false, S2 is true

D

S1 is false, S2 is false

Consider a main memory with five page frames and the following sequence of page references: 3, 8, 2, 3, 9, 1, 6, 3, 8, 9, 3, 6, 2, 1, 3. Which one of the following is true with respect to page replacement policies First In First Out (FIFO) and Least Recently Used (LRU)?

A

Both incur the same number of page faults

B

FIFO incurs 2 more page faults than LRU

C

LRU incurs 2 more page faults than FIFO

D

FIFO incurs 1 more page faults than LRU

Consider a process executing on an operating system that uses demand paging. The average time for a memory access in the system is M units if the corresponding memory page is available in memory, and D units if the memory access causes a page fault. It has been experimental measured that the average time taken for a memory access in the process is X units. Which one of the following is the correct expression for the page fault rate experienced by the process?

A

(D - M) / (X - M)

B

(X - M) / (D - M)

C

(D - X) / (D - M)

D

(X - M) / (D - X)

Consider the following page reference string: 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 Assume that there are three-page frames which are initially empty. Let LRU, FIFO, OPTIMAL denote the number of page faults under the corresponding page replacement strategy. Then, which of the following is TRUE?

A

LRU = FIFO = OPTIMAL

B

LRU = OPTIMAL

C

FIFO < OPTIMAL < LRU

D

OPTIMAL < FIFO < LRU

How many page faults will occur if FIFO Page replacement algorithm is used for the following reference string with three-page frames? 7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2, 1, 2, 0, 1, 7, 0, 1

A

17

B

14

C

16

D

15

Consider a main memory with 3 page frames in the following sequence of page reference 3, 4, 2, 3, 9, 1, 6, 3, 4, 9. What is the number of page fault using FIFO page replacement algorithm?

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