CS 446 Quiz Questions

Question 1

[Select all that apply] Which of the following requires the operating system to involve itself with paging? Process creation Process termination Process blocking Process execution

Accepted Answer

Process creation Process termination Process execution

Question 2

[Select all that apply]Which of the following are benefits of using global page allocation over local page allocation

Less thrashing
Page frame consistency
Differentiates number of pages per process based on criteria
Less memory wasted

Accepted Answer

Less thrashing Differentiates number of pages per process based on criteria Less memory wasted

Question 3

[Select all that apply]Which of the following best describes the effect of using a large page size?

Internal fragmentation is more likely than if the page were smaller
Page table entry number is increased
Shorter page table load times
Less space is used in the TLB

Accepted Answer

Internal fragmentation is more likely than if the page were smaller Shorter page table load times Less space is used in the TLB

Question 4

[T/F] The paging daemon is responsible for ensuring that some number (or more) free page frames exist

Accepted Answer

True

Question 5

[T/F]Larger sized pages result in a larger number of page table entries.

Accepted Answer

False

Question 6

[T/F]Segmentation causes internal fragmentation more often than external fragmentation

Accepted Answer

False

Question 7

[T/F]The MMU is responsible for setting the policy that decides which pages to swap on and off RAM

Accepted Answer

False

Question 8

[T/F]The modified bit is also known as the dirty bit.

Accepted Answer

True

Question 9

[T/F]The optimal page replacement algorithm is not implementable in practice because the OS does not know how many instructions will be executed by a process before running it.

Accepted Answer

True

Question 10

A benefit of a VM is that it is portable. T/F

Accepted Answer

True

Question 11

A container is a VM T/F

Accepted Answer

False

Question 12

A hypervisor is a type of microkernel T/F

Accepted Answer

False

Question 13

A keyboard is an output device T/F

Accepted Answer

False

Question 14

A page fault occurs. Order the series of events that takes place

OS loads the page provided by the page handler
CPU traps to kernel
MMU Sends signal to CPU
Page fault handler checks where fault occurred
OS re-executes faulting instruction
Page fault handler gathers data structures and necessary pages

Accepted Answer

first: MMU Sends signal to CPU
second: CPU traps to kernel
third: Page fault handler checks where fault occurred
fourth: Page fault handler gathers data structures and necessary pages
fifth: OS loads the page provided by the page handler
sixth: OS re-executes faulting instruction

Question 15

All memory reserved for a process must be contiguous, regardless of memory allocation method. T/F

Accepted Answer

False

Question 16

Atomic operations ensure that resources/data do not end up in an incorrect intermediate state

Accepted Answer

True

Question 17

By design, which of the following operating systems are designed to handle many requests from many different users at one time? [select all that apply] server mainframe pc sensor node system

Accepted Answer

server mainframe

Question 18

Character devices store IO device input as fixed-size, consecutive blocks. T/F

Accepted Answer

False

Question 19

Cloud services help ensure data redundancy. T/F

Accepted Answer

True

Question 20

Coalescing waits until a device sends a significant number of requests, which are sent all at once to the driver. T/F

Accepted Answer

True

Question 21

Each file in a unix OS is associated with a read, write, and execute bit for the creator, their access group, and others. T/F

Accepted Answer

True

Question 22

Every file, including directories, has an associated, unique inode. T/F

Accepted Answer

True

Question 23

Files that begin with . are hidden from users unless explicitly searched for. T/F

Accepted Answer

True

Question 24

For each of the following, match the synchronization model with its description

Accepted Answer

Producer Consumer Model - Threads/process obtain (for reference) and modify the resources in a shared buffer
Reader Writer Model - Multiple 1+ threads/process obtain (for reference) a resource while another/thread/process is allowed to ...
Dining Philosophers Model - N threads synchronize access to N resources, where each thread/process needs access to 2+ resource

Question 25

For each of the locker operations below, match them with the associated step number (first, second, third)

Accepted Answer

Create Lock - 1st Initialize Lock - 2nd Thread Gains Lock - 3rd Thread Releases Lock - 4th Lock is Destroyed - 5th

Question 26

For each type of lock, select the most appropriate description

Accepted Answer

Spin Block - If mutex is available, the thread will take it. If not, the thread is placed in the waiting queue
Spin Wait - If mutex is available, the thread will take it. If not, the thread will stay on the CUP until the lock is released
Monitor - An object that encapsulates the critical region, its lock (mutex or CV), and any operations to coordinate the lock
Condition Variable (CV) - Signals when the lock has been freed so that a thread/process can acquire it more quickly
Semaphore - Acts as a lock to many threads across many processes

Question 27

Fork launches a new command in the generated child process. T/F

Accepted Answer

False

Question 28

HDDs are faster to write to than SSDs. T/F

Accepted Answer

False

Question 29

If I introduce a new file to an operating system, it must be mounted either manually or by the OS itself. T/F

Accepted Answer

True

Question 30

If process A is using a critical region, process B should be able to read from the critical region at the same time.

Accepted Answer

False

Question 31

if we're more concerned with performance than with security, TCP remote protocols are best. T/F

Accepted Answer

False

Question 32

In linux, directories are just specialized files. T/F

Accepted Answer

True

Question 33

Linux backended systems use one to one thread mappings from user space to kernel space threads. T/F

Accepted Answer

True

Question 34

main is the entry point for C programs, and this is where the OS will begin execution. T/F

Accepted Answer

True

Question 35

Page faults occur when an entire process cannot be brought into memory at once. T/F

Accepted Answer

False

Question 36

Paging requires less memory than directly allocating a memory space. T/F

Accepted Answer

False

Question 37

Parallelism is preferred over multithreading when there is a shared data dependency among threads.

Accepted Answer

False

Question 38

Processes usually share all of their information with other processes T/F

Accepted Answer

False

Question 39

SSDs are slower to read from than HDD. T/F

Accepted Answer

False

Question 40

SSDs do not use pages T/F

Accepted Answer

False

Question 41

Synchronization is concerned with which of the following?

Accepted Answer

sharing data coordinating CPU cores efficiency fairness

Question 42

The chmod command will allow a file's protections to be changed. T/F

Accepted Answer

True

Question 43

The clock algorithm is the most efficient algorithm of the algorithms discussed in class. T/F

Accepted Answer

False

Question 44

The device controller consists of an electronic and a mechanical component T/F

Accepted Answer

True

Question 45

The operating system should be able to interrupt any thread at any time. T/F

Accepted Answer

False

Question 46

The process with PID 1 in most unix backed operating systems is init T/F

Accepted Answer

True

Question 47

The process with PID 1 in most unix backed operating systems is init. T/F

Accepted Answer

True

Question 48

The purpose of a container is to package an app and its library dependencies for shipment/safety. T/F

Accepted Answer

True

Question 49

The root of unix file systems is denoted with C: T/F

Accepted Answer

False

Question 50

The size of the physical address space and a process' virtual address space must be the same. T/F

Accepted Answer

False

Question 51

The smallest OS that uses the fewest resources is a sensor node OS. T/F

Accepted Answer

False

Question 52

The thread API calls (create, join, exit) used by a program are dependent on lock type chosen

Accepted Answer

True

Question 53

Threads have their own copy of each child process. T/F

Accepted Answer

False

Question 54

Threads share address space, global variables, and lists of open files. T/F

Accepted Answer

True

Question 55

Time sharing implies that a single process is given the entire CPU. T/F

Accepted Answer

True

Question 56

Trapping to kernel is expensive and should usually be minimized. T/F

Accepted Answer

True

Question 57

Ubuntu prioritizes ease of use over security. T/F

Accepted Answer

False

Question 58

Using a base register to allocate memory ensures that processes are isolated from each other. T/F

Accepted Answer

True

Question 59

Using a base register to translate virtual memory to physical memory prevents one process from accidentally overwriting another process' address space. T/F

Accepted Answer

False

Question 60

Using chroot to create a container segregates the file system and memory space of the container from the host OS T/F

Accepted Answer

False

Question 61

What is the purpose of the translation lookaside buffer?

To map all addresses from virtual to physical memory
To store the address of all of the pages that have been created for a process
To cache frequently used pages so that they can be found faster
To modify the memory space and its partitions

Accepted Answer

To cache frequently used pages so that they can be found faster

Question 62

What is the role of the operating system in networking?

It manages access permissions
It allows the hardware to directly interact with the user space when a request is sent
It provides the software necessary for networking communications
It allows the user to directly manipulate the communication channel

Accepted Answer

It manages access permissions It provides the software necessary for networking communications

Question 63

When a process is created, the operating system automatically adds which of the following to the address space [select all that apply] Empty memory space Threads Heap Code

Accepted Answer

Empty memory space Heap Code

Question 64

When a thread table is created in kernel space, a process table is unnecessary

Accepted Answer

False

CS 446 Quiz Questions

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