Question 1

A sign of thrashing is

Accepted Answer

A)  the CPU utilization increases as the degree of multiprogramming is increased. 
B)  the CPU utilization decreases as the degree of multiprogramming is increased. 
C)  the CPU utilization increases as the number of pages allocated to each process is increased. 
D)  the CPU utilization decreases as the number of pages allocated to each process is increased. 
A)  the CPU utilization increases as the degree of multiprogramming is increased. 
B)  the CPU utilization decreases as the degree of multiprogramming is increased. 
C)  the CPU utilization increases as the number of pages allocated to each process is increased. 
D)  the CPU utilization decreases as the number of pages allocated to each process is increased.

Question 2

The working set strategy

Accepted Answer

A)  swaps out a process if OS cannot allocate enough pages to accommodate its working set. 
B)  swaps in a new process if there is enough memory available to accommodate its working set. 
C)  keeps the degree of multiprogramming as high as possible while preventing thrashing. 
D)  All of the above. 
A)  swaps out a process if OS cannot allocate enough pages to accommodate its working set. 
B)  swaps in a new process if there is enough memory available to accommodate its working set. 
C)  keeps the degree of multiprogramming as high as possible while preventing thrashing. 
D)  All of the above.

Question 3

Stack algorithms can never exhibit Belady's anomaly.

Accepted Answer

A) True 
 B)False

Question 4

Explain the distinction between global allocation versus local allocation.

Accepted Answer

When a process incurs a page fault, it m

Question 5

Prepaging an executable program is much easier than prepaging a text file.

Accepted Answer

A) True 
 B)False

Question 6

Some operating systems keep a pool of free frames so that the frequency of page faults is lowered.

Accepted Answer

A) True 
 B)False

Question 7

Lock bit is NOT used for which of the following cases:

Accepted Answer

A)  the page that is being used for I/O. 
B)  some OS pages. 
C)  a new page that has just been brought in. 
D)  a page that belongs to a high priority process. 
A)  the page that is being used for I/O. 
B)  some OS pages. 
C)  a new page that has just been brought in. 
D)  a page that belongs to a high priority process.

Question 8

Given the reference string of page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 3 and a system with three page frames, what is the final configuration of the three frames after the OPT algorithm is applied?

Accepted Answer

A)  1, 3, 4 
B)  1, 2, 3 
C)  2, 3, 4 
D)  1, 2, 1 
A)  1, 3, 4 
B)  1, 2, 3 
C)  2, 3, 4 
D)  1, 2, 1

Question 9

Explain how copy-on-write operates.

Accepted Answer

Copy-on-write (COW) initially allows a p

Question 10

A drawback of equal or proportional allocation is that

Accepted Answer

A)  they are very expensive to compute. 
B)  the processes that arrive earlier get more pages than the processes arriving later. 
C)  the allocation varies according to the degree of multiprogramming. 
D)  a high-priority process is treated the same as a low-priority process. 
A)  they are very expensive to compute. 
B)  the processes that arrive earlier get more pages than the processes arriving later. 
C)  the allocation varies according to the degree of multiprogramming. 
D)  a high-priority process is treated the same as a low-priority process.

Question 11

How are lock bits useful in I/O requests?

Accepted Answer

A lock bit is associated with every fram

Question 12

Which of the following is true about the strategy that uses page fault frequency (PFF) to prevent thrashing?

Accepted Answer

A)  A new page is allocated to a process if PFF is too high. 
B)  A page is deallocated from a process if the PFF is too low. 
C)  A new process may be swapped in if PFF is too low. 
D)  All of the above. 
A)  A new page is allocated to a process if PFF is too high. 
B)  A page is deallocated from a process if the PFF is too low. 
C)  A new process may be swapped in if PFF is too low. 
D)  All of the above.

Question 13

Explain how working set model works.

Accepted Answer

The working set model uses an integer pa

Question 14

In Additional-Reference-Bits algorithm,

Accepted Answer

A)  the least-recently used page is identified very efficiently on a page fault. 
B)  a group of pages that have not been used recently are efficiently identified. 
C)  a page that has been referenced most recently is identified. 
D)  None of the above. 
A)  the least-recently used page is identified very efficiently on a page fault. 
B)  a group of pages that have not been used recently are efficiently identified. 
C)  a page that has been referenced most recently is identified. 
D)  None of the above.

A sign of thrashing is

The working set strategy

Stack algorithms can never exhibit Belady's anomaly.

Explain the distinction between global allocation versus local allocation.

Prepaging an executable program is much easier than prepaging a text file.

Some operating systems keep a pool of free frames so that the frequency of page faults is lowered.

Lock bit is NOT used for which of the following cases:

Given the reference string of page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 3 and a system with three page frames, what is the final configuration of the three frames after the OPT algorithm is applied?

Explain how copy-on-write operates.

A drawback of equal or proportional allocation is that

How are lock bits useful in I/O requests?

Which of the following is true about the strategy that uses page fault frequency (PFF) to prevent thrashing?

Explain how working set model works.

In Additional-Reference-Bits algorithm,

Introduction

Operating-System Structures

Processes

Threads Concurrency

Cpu Scheduling

Synchronization Tools

Synchronization Examples

Deadlocks

Main Memory

Mass-Storage Structure

Io Systems

File-System Interface

File-System Implementation

File-System Internals

Security

Protection

Filters

Exam 10: Virtual Memory

A sign of thrashing is

The working set strategy

Stack algorithms can never exhibit Belady's anomaly.

Explain the distinction between global allocation versus local allocation.

Prepaging an executable program is much easier than prepaging a text file.

Some operating systems keep a pool of free frames so that the frequency of page faults is lowered.

Lock bit is NOT used for which of the following cases:

Given the reference string of page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 3 and a system with three page frames, what is the final configuration of the three frames after the OPT algorithm is applied?

Explain how copy-on-write operates.

A drawback of equal or proportional allocation is that

How are lock bits useful in I/O requests?

Which of the following is true about the strategy that uses page fault frequency (PFF) to prevent thrashing?

Explain how working set model works.

In Additional-Reference-Bits algorithm,

Introduction

Operating-System Structures

Processes

Threads Concurrency

Cpu Scheduling

Synchronization Tools

Synchronization Examples

Deadlocks

Main Memory

Mass-Storage Structure

Io Systems

File-System Interface

File-System Implementation

File-System Internals

Security

Protection

Filters