3305 Final Exam Review
1. To select a process to run in a multiprocessor architecture, the scheduler will assign processes to a core from
Either a common or a private ready queue is possible
Common ready queue
Private ready queue
2. Suppose a program can run 10% serial and 90% parallel. Using Amdahl's Law, calculate the expected performance gain by adding 16 cores.
15
3.3
6.4
12.1
3. Multiple pages with similar code and data structures are known as
None of these
Related pages
pages with the same locality
Neighbour pages
4. A differential backup can also be known as
an incremental backup
None of these
5. Which of the following is a reason for a file system to not use indexed allocation?
Random access is slow
These are all reasons to not use indexed allocation
The index block may not be large enough to hold all indexes
It suffers from external fragmentation
6. Another name for a virtual machine manager is
Virtual visor
Vmware
Guest kernel
Hypervisor
7. A backup that is held off-site and/or disconnected from any network is known as
a full backup
a differential backup
a cold storage backup
an incremental backup
8. Applying labels to objects and domains and permitting the action when the labels match is known as
Role-based access control
Label-based access control
Mandatory access control
Classified access control
9. Which of the following is a benefit to virtualization
Virtual machines do not need to be expanded as the workload grows
Easier to consolidate multiple operating systems on the same host system
Guest operating systems can read and write each other's data
These are all benefits to virtualization
10. If the operating system cannot find a free frame in the free frame list, the operating system will
Send an error to the requesting process
Find a frame that can be written to disk and use that frame for the new request
All of these are common strategies
Crash dump
11. Which of the following is a reason for a file system to not use contiguous allocation?
These are all reasons to not choose contiguous allocation
Performance is poor
Disk space may be difficult to find for large files
Difficult to implement
12. Unlike forking, if the parent thread of a multithreaded process exits, all of its 'child' threads will also exit.
True
False
13. A context switch consumes CPU time
True
False
14. To notify a process that a particular event has occurred, one would send the process
A signal
A handler
An interrupt
An alarm
15. A worm requires user input to propagate
True
False
16. Assigning more memory to all the guest VMs than the host system physically has is known as
Oversubscribing
Virtual memory
Paging
Deduplication
17. It is sometimes a good idea to keep a task assigned to a specific core rather than re-balance it to another core
True
False
18. In Round-Robin CPU scheduling, if there are 10 processes in the ready queue and the time quantum is 3ms, then no process waits more than
None of these
20ms
30ms
27ms
19. Which of the following is not a factor to consider when deciding which storage medium to use
Volatility
Cost
Speed
Weight
20. The TLB holds a copy of the page table.
True
False
21. Which of the following methods are not used to keep track of frame usage?
Counters
All of these can be used.
Stack
Hash map
22. When two processes communicate using an unbounded buffer, the consumer may need to wait before reading from the buffer.
True
False
23. Swap space is assigned to
Dedicated files on a filesystem
Either of these are possible
Raw partitions
None of these
24. Which of the following is the best definition of a virtual file system?
A file system implemented in user mode instead of kernel mode
A uniform API provided by the operating system to make the underlying file system operations transparent to the user
A file system designed to manage virtual machines
An API created for network-based file systems such as NFS
25. Main memory is an example of Nonvolatile storage (NVS)
True
False
26. Before a user can use the files in a file system, the file system must be
All of these
Opened
Partitioned
Mounted
27. Main memory is an example of Nonvolatile storage (NVS)
True
False
28. Which of the following is not a service commonly provided by an operating system?
I/O operations
Code compilation
Error detection
Process communication
29. Message passing is typically faster than shared memory.
True
False
30. If using a valid/invalid bit in a demand paging strategy, every page will generate a page fault at least once.
True
False
31. Validating a username and password is known as
Authorization
Encryption
Authentication
None of these
32. A file system should have good performance with many features without sacrificing reliability
True
False
33. A CPU may have multiple layers of caching
True
False
34. Consider the following processes in the ready queue with the following CPU burst times. Match the following scheduling algorithms with the order of processes
FCFS: P1, P2, P3
SJF: P2, P3, P1
LCFS: P3, P2, P1
RR (Quantum 10): P1, P2, P3, P1
35. In the context of file systems, FUSE stands for
Files under system events
File based user structures
Fragmentation unless sector extents
File system user space
36. Most modern operating systems use a nonpreemptive scheduling scheme
True
False
37. For efficiency, modern disks often maintain their own list of disk requests and act on them using built-in algorithms
True
False
38. The size of the memory allocated for a process is stored in
The relocation register
The process size register
The limit register
The base register
39. The list of free frames is maintained by
The MMU
The operating system
The running process
None of these
40. Pages can be labelled as read-only
True
False
41. When two processes communicate using an unbounded buffer, the producer may need to wait before writing to the buffer.
True
False
42. A common approach used by most modern operating systems to manage process synchronization is to temporarily disable interrupts
True
False
43. Which of the following is not a service commonly provided by an operating system?
Process communication
I/O operations
Error detection
Code compilation
44. If an operating system is permitting multiple processes to write to a locked file, this is an example of
Exclusive lock with advisory locking
Exclusive lock with mandatory locking
Shared lock with mandatory locking
None of these
45. If a program declares a variable before a fork() the child and the parent can communicate with one another using that variable.
True
False
46. A parent and child process always share the same block of memory
True
False
47. Using a first-fit algorithm on fixed partitions, match the following process blocks with the following partitions (*None of the Above* means this partition is not used) Process Size P1 20 P2 400 P3 150 P4 175 Partition Size 1 100 2 200 3 200 4 300 5 400 6 500 7 500
P2
P1
P4
P3
None of the Above
48. A parent process must wait for its child processes to finish before it can execute instructions.
True
False
49. Message passing is typically faster than shared memory.
True
False
50. If the CPU wants to use memory address 256, and the relocation register holds the value 256, and the limit register holds the value 512, then the physical address in memory is (assume contiguous memory allocation)
512 but an error will be generated
512 and no error will be generated
There is not enough information
256 and no error will be generated
51. In a nonpreemptive scheduling scheme, the next process to run is
The next process in the queue
The process in the queue with the highest priority
A randomly selected process
The process in the queue with the shortest run time
52. An area of memory containing process information such as process state, CPU registers, I/O status information, etc. is known as a
CPU Control Block
Process Control Block
CPU Registry
Process Status File
53. All modern operating system employ a layered operating system structure only
True
False
54. Symmetric and asymmetric encryption/decryption are roughly equivalent in terms of computation power required
True
False
55. When an interrupt is signaled, the CPU will finish its current task and address the interrupt when the task is complete.
True
False
56. If an application fails, the operating system can sometimes generate a
File-system dump
Crash dump
Application dump
Core dump
57. Higher page faults usually means higher effective memory access time
True
False
58. Interrupts are:
An efficient way of multitasking
Generated by exceptional conditions in the CPU
Signals that inform the OS that an event has occurred
Used to start a computer
59. A process is by definition a program in execution
True
False
60. Which storage medium certain process data is stored on does not influence process speed
True
False
61. A parent process must wait for its child processes to finish before it can execute instructions.
True
False
62. The greater the serial portion of a task, the greater the expected performance gains by adding parallelism.
True
False
63. Shared data that is always read-only does not necessarily need to be used in a critical section.
True
False
64. The primary purpose of an operating system is:
To make the most efficient use of the computer hardware
To allow people to use the computer
To keep systems programmers employed
To make computers easier to use
65. Which storage medium certain process data is stored on does not influence process speed
True
False
66. In Round-Robin CPU scheduling, if there are 10 processes in the ready queue and the time quantum is 3ms, then no process waits more than
27ms
30ms
20ms
None of these
67. Rank the following locations on a hard drive disk from 1 (most specific/smallest block) to 4 (most generic/largest block) 1. Sector 2. Track 3. Platter/Cylinder
1
2
3
68. A stack is an example of a data structure with good locality
True
False
69. The valid/invalid bit in the page table is used to indicate whether the page is mapped to a free frame or not.
True
False
70. Sort the following storage mediums from fastest to slowest 1. Registers 2. Main memory 3. Hard drive 4. Cache
4 (Slowest)
3
2
1 (Fastest)
71. A semaphore can be implemented as a mutex lock
True
False
72. With a Multilevel Feedback Queue scheduling algorithm, once the scheduler has placed the process in a queue, it could be moved to a different queue later.
True
False
73. A context switch consumes CPU time
True
False
74. One drawback to Priority scheduling is
All of these
Process priority cannot change
Longer average waiting time compared to most other scheduling algorithms
The potential for starvation
75. Consider a logical address space of 12 bits. If each page size is 8 bits, how many pages are there in the logical address? (Assume the entire address space is dedicated to the page number and offset. Do not consider other bits like the valid/invalid or protection bit)
32 pages
None of these
4 pages
16 pages
76. Which storage medium certain process data is stored on does not influence process speed
True
False
77. Which of the following file system types are common in UNIX/Linux systems
zfs
ext3
All of these are common
ext4
78. Suppose a program can run 20% serial and 80% parallel. Using Amdahl's Law, calculate the expected performance gain by adding 4 cores.
2
1.5
4
2.5
79. Which of the following is not a component of a process
Heap
Text
These are all components of a process
Stack
80. On a DFS, all the actions performed by a client between the open() and the close() call is known as
File session
DFS
File block
NFS
81. A context switch consumes CPU time
True
False
82. Binding the address of data to physical addresses in memory occurs at
Load time
Any of these are possible
Execution time
Compile time
83. Forcing programs to run inside a limited environment is known as
Sandboxing
System Integrity Protection
System-call filtering
Code-signing
84. To balance tasks across multicores, an operating system may employ which strategy?
Periodically check for cores with too many tasks and push some of those tasks to other cores
Either strategy could be used
Periodically check for cores that have too few tasks and pull some tasks from other cores
85. Windows has been used as a desktop operating system only
True
False
86. Which of the following is the best definition of a translation look-aside buffer
A cache in the CPU that holds a subset of the page table
B A register in the CPU that holds the address in memory of the page table
C. A table in memory that holds the list of pages and frames
D. A register In the CPU that holds the see of the page table
87. Consider the following processes in the ready queue with the following CPU burst times. Match the following scheduling algorithms with the order of processes
FCFS: P1, P2, P3
SJF: P2, P3, P1
LCFS: P3, P2, P1
RR (Quantum 10): P1, P2, P3, P1
88. An area of memory containing process information such as process state, CPU registers, I/O status information, etc is known as
Process Status File
CPU Registry
CPU Control Block
Process Control Block
89. If an application fails the operating system can sometimes generate a
Core dump
Application dump
Crash dump
File-system dump
90. Main memory is an example of Nonvolatile storage (NVS)
True
False
91. The first computers used a very basic operating system
True
False
92. Which of the following is not a component of a process?
Heap
These are all components of a process
Stack
Text
93. Windows has been used as a desktop operating system only
True
False
94. For performance reasons, operating systems will usually let the free-frame list reach zero and use a page-out/page-in strategy when frames are needed.
True
False
95. In a nonpreemptive scheduling scheme, the next process to run is
The process in the queue with the shortest run time
A randomly selected process
The next process in the queue
The process in the queue with the highest priority
96. The greater the serial portion of a task, the greater the expected performance gains by adding parallelism.
True
False
97. Which of the following is not a factor to consider when deciding which storage medium to use
Volatility
Weight
Cost
Speed
98. In the event of disk failure, data loss is likely to occur in which RAID configuration?
RAID 0
RAID 1
RAID 5
None of these
99. Which of the following is the best definition for security?
Protecting data from theft
Encrypting sensitive data from malicious attacks
A set of mechanisms to provide protection
A measure of confidence that the data on a system is secure
100. Emulation and Virtualization are identical terms
True
False
101. Which of the following is the best definition for a WAN
A WAN is synonymous with the Internet
Any wifi network
A network consisting of computers across a country
A network consisting of all the computers in the same building
102. Context switching is managed by the
Dispatcher
Switcher
CPU
Scheduler
103. A system is using virtual memory if
There are more pages than frames
There are more frames than pages
There are an equal number of pages and frames
Any of these are possible
104. A backup that only contains the changed files from the previous backup is known as
a cumulative backup
an incremental backup
a diferential backup
a full backup
105. The CPU cache is storage space built into the CPU itself
True
False
106. Changing from one user to a user with higher privileges is known as
Impersonating privilege
Sudo-ing
Privilege escalation
Two-step authentication
107. Only permitting programs to run if they have been approved by the vendor is known as
System-call filtering
Code-signing
Sandboxing
System Integrity Protection
108. A process is by definition a program in execution
True
False
109. In Multilevel queue scheduling, which of the following is not true?
Processes can move between the queues
Starvation is possible
Each queue is assigned a priority level
Different queues can use different scheduling algorithms
110. A trap to the operating system when a page is invalid is known as
A swap
None of these
A page fault
An Invalid reference
111. Virtualization and emulation are synonymous
True
False
112. Which of the following is not a basic file operation that an operating system needs to provide functionality for?
Move
Create
Truncate
D All of these are basic file operations
113. Which of the following is a reason why two processes may want to cooperate
All of these
Speed
Sharing Information
Convenience
114. DLLs are loaded when requested by a process and are not shared with other processes
True
False
115. Which of the following is not a page replacement algorithm?
These are all valid algorithms
Least frequently used
Shortest job first
First-in first-out
116. With a Multilevel Feedback Queue scheduling algorithm, once the scheduler has placed the process in a queue, it could be moved to a different queue later.
True
False
117. Consider a page size of 1024 bytes, what is the internal fragmentation on a process using 15,616 bytes
None of these
0 bytes
256 bytes
768 bytes
118. Contiguous memory allocation is also commonly referred to as
Virtual memory
None of these are valid terms
Paging
Swapping
119. One drawback to Priority scheduling is
Longer average waiting time compared to most other scheduling algorithms
The potential for starvation
All of these
Process priority cannot change
120. In the context of file systems, a contiguous set of sectors that can be assigned to parts of a file is known as a
track
block
volume
FCB
121. The master boot record typically contains all the code necessary to boot the operating system
True
False
122. In modern computing, multithreading an application is no longer a common strategy
True
False
123. Which of the following is a possible reason to load only part of a program in memory?
More programs can run concurrently
All of these are possible reasons to load only part of a program into memory
Some parts of some data structures are rarely used
Some subroutines are rarely used
124. Main memory is an example of Nonvolatile storage
True
False
125. A child may share which resources with a parent?
All
None
All of these are possibilities
Some
126. The core operating system files (eg. Kernel, libraries) are found in which partition?
None of these
Swap partition
Root partition
Boot partition
127. Managing what is in memory and when is the responsibility of the running process
True
False
128. In a one-to-one multithreading model, the developer can use only single-threading.
True
False
129. A software-generated interrupt is known as a
Segfault
Signal
Trap
Overflow
130. An operating system must have a user interface
True
False
131. Processes that need more frames will use one from their own list of free frames
True
False
132. If a process has multiple threads and one of the threads calls fork(), the child process will also be multithreaded.
True
False
133. Which of the following is not an on-storage file system structure discussed in class?
System-wide open-file table
Volume control block
FCB
These are all on-storage file system structures
134. Most modern operating systems provide an abstraction between the logical files and the physical addresses of the files on disk
True
False
135. Consider a logical address space of 2^16. If there are 32 pages in the logical address, what is the size of each page? (Assume the entire address space is dedicated to the page number and o"set. Do not consider other bits like the valid/invalid bit)
2048 bits
1024 bits
4096 bits
None of these
136. Linux represents the system state and other attributes under which directory?
/usr
/proc
/dev
/etc
137. Which of the following is not a necessary criterion for a solution to the critical section problem?
All processes with a critical section must employ mutual exclusion
If the shared resource is available for use, any process that wants to use it can secure the resource and enter its critical section
A process may not prevent other processes from ever entering their critical section
All processes that wish to use a shared resource must have an equal chance of obtaining the shared resource
138. Most modern operating systems employ which type of directory structure?
Single
Two-level
Tree
Acyclic Graph
139. Before the data in a file can be used by a process, that data must first be loaded into memory.
True
False
140. Which of the following is not a factor to consider when deciding which storage medium to use
Volatility
Cost
Speed
Weight
141. To prevent a process from running too long, the operating system uses a ____ to limit CPU time
Timer
Cache
Switch
DMA
142. Peterson's solution is a common strategy employed by modern operating systems to solve the critical section problem
True
False
143. If the developer does not write a handler for a signal, the kernel has a default handler for the signal
True
False
144. When a process changes from one to another, the operating system must perform a
Context Switch
Save State
Reload
Interrupt
145. Which of the following is a reason why two processes may want to cooperate?
Speed
All of these
Convenience
Sharing Information
146. Consider a logical address space of 4 bytes (32 bits). If the page size is 1 byte (8 bits), how many pages can be used? (Assume the entire address space is dedicated to the page number and offset. Do not consider other bits like the valid/invalid or protection bit)
2^24
2^8
2^16
None of these
147. With asymmetric cryptography, the same key is used for both encryption and decryption
True
False
148. Using dynamic partitions for contiguous memory allocation suffers from
External fragmentation
Neither of these
Both of these
Internal fragmentation
149. Which of the following is a reason why two processes may want to cooperate?
Speed
Convenience
Sharing Information
All of these
150. Which of the following is not a benefit of multithreading?
Threads can easily share variables
CPU instructions execute faster when run in a thread
Applications respond to user input faster
Threads can run on multiple CPUs or multiple cores concurrently
151. Which of the following is not true about ordinary pipes?
It uses non-blocking send
It uses blocking receive
It uses indirect message passing
It uses a bounded capacity buffer
152. Round-Robin scheduling ensures that starvation cannot occur
True
False
153. A process is, by definition, a program in execution
True
False
154. Unlike forking, if the 'parent' thread of a multithreaded process exits, all of its 'child' threads will also exit.
True
False
155. If a program declares a variable before a fork() the child and the parent can communicate with one another using that variable
True
False
156. Operating systems require that all files on a file system follow one of these three structures: Free-form Simple record Complex record
True
False
157. If an application fails, the operating system can sometimes generate a
Application dump
Crash dump
Core dump
File-system dump
158. Most modern operating systems will implement techniques to ensure the CPU does not update areas of memory it should not update.
True
False
159. If an application fails the operating system can sometimes generate a
Core dump
Application dump
Crash dump
File-system dump
160. For efficiency, NVM devices typically write data at low level pages.
True
False
161. Using data in registers is faster than using data in memory
True
False
162. The operating system kernel is:
The same thing as the CPU
A low-level part of the system that interfaces directly with the hardware
An application like a word processor
Part of the application software
163. If a program declares a variable before a fork(), the child and the parent can communicate with one another using that variable.
True
False
164. A parent and child process always share the same block of memory
True
False
165. Direct communication message passing is an example of which type of communication model?
These are all possible
One-to-many
One-to-one
Many-to-many
166. A process whose parent process has already terminated is known as a
Runaway process
Non-waiting process
Zombie process
Orphan process
167. Consider the relationship between pages and frames. For any operating system which of the following statements is not a reasonable implementation?
All of these are reasonable implementation
There can be an equal number of pages and frames
There can be more frames than pages
There can be more pages than frames
168. Managing what is in memory and when is the responsibility of the running process
True
False
169. A parent process must wait for its child processes to finish before it can execute instructions
True
False
170. One drawback to Priority scheduling is
Longer average waiting time compared to most other scheduling algorithms
Process priority cannot change
All of these
The potential for starvation
171. Mutex locks and semaphores are identical concepts. Programmers choose one or the other as a matter of style.
True
False
172. To prevent a process from running too long the operating system uses a
DMA to limit CPU time
Switch
Cache
Timer
173. What is the average wait time for these processes if using the SJF scheduling algorithm
~2.3ms
~6.7ms
There is not enough information
~2.5ms
174. A process whose parent process that does not wait on it is known as a
Orphan process
Non-waited process
Zombie process
Runaway process
175. If the data required by a process is only found on disk, the CPU must always ask the operating system to handle retrieving the data
True
False
176. Asymmetric multiprocessing is the most common multiprocessing strategy used by operating systems.
True
False
177. Consider a system with swap space held on an HDD with an access time of 10,000,000 microseconds and a memory access time of 1 microseconds. Suppose a page fault occurs 1/1000 accesses, the effective memory access time is
1.100 microseconds
1.999 microseconds
None of these
2.001 microseconds
178. Which of the following is a benefit of using a many-to-one multithreading model?
There doesn't have to be a relationship between user threads and kernel threads
More efficient use of resources
The developer doesn't have to manage the threads. The kernel manages the threads instead.
The kernel limits how many threads a developer can actually create, limiting the developer's ability to overwhelm the system
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