Operating Systems Fundamentals

Front 1

How does a Deadlock occur?

Back 1

When 2 or more processes are trying to use the same resources

Front 2

What is a deadlock?

Back 2

When 2 or more competing processes are waiting for the other to finish, so neither ever does

Front 3

A resource management program which ensures that shared resources are not to be taken by more than one process at a time and detects every possible deadlock situation does what? A) Creates a child process B) Prevents deadlock C) Duplicates resources (Input A, B, or C)

Back 3

B

Front 4

What are the differences between parent and child processes? True or False: Threads share the same address space, global variables, codes, data, files and signal handlers with the process has created those threads

Back 4

True

Front 5

What are the differences between parent and child processes? Fill in the blanks: __________ are used to schedule program execution on ______.

Back 5

Threads CPU

Front 6

What are the differences between parent and child processes? Fill in the blanks: ________ are used to group resources together.

Back 6

Processes

Front 7

What are the differences between parent and child processes? Fill in the blanks: ___________ processes has different address space from the __________ process, and often duplicate some / all the global variables, codes, data, files and signal handlers of the parent process.

Back 7

Child Parent

Front 8

Multiple choice: Multi-threads is the ability for a CPU to run more than 1 ____________ at a time. A) Thread B) Process C) Both Thread and Process D) None of the above (Input A, B, C, or D)

Back 8

C

Front 9

True or False: Its not possible to have a deadlock situation with threads?

Back 9

False

Front 10

It is the main memory of a computer

Back 10

RAM

Front 11

Allows a system to read and write data onto it

Back 11

RAM

Front 12

All data will disappear after system reboot

Back 12

RAM

Front 13

It is a permanent Memory

Back 13

ROM

Front 14

Allows system to read data from it

Back 14

ROM

Front 15

All data remains there after system reboot

Back 15

ROM

Front 16

How many bits represent 1 byte of memory?

Back 16

8 bits

Front 17

We usually use _______ when we talk about data speed / data bandwidth e.g. 32 ____, 100 Mbps

Back 17

bits

Front 18

We normally use _______ when we talk about data capacity. E.g. 16GB memory, 1 TB hard disk.

Back 18

bytes

Front 19

Inter-process communication (IPC) Message passing method needs to know addresses of both the sender and the recipient? True or False

Back 19

True

Front 20

True or False: Only the OS knows the physical address of memory?

Back 20

False

Hint 20

No one knows, not even the OS

Front 21

The address of a process is used when one process wants to communicate with another process True or False

Back 21

True

Front 22

Fill in the blanks: ___________ _____________ is a mechanism in which a process can be swapped temporarily out of main _____________ to a backing store and then brought back into memory for continued execution

Back 22

Memory swapping memory

Front 23

Fill in the blanks: A ____________ may swap out of the memory if it is not running (or just waiting for something) and available spaces can be used for ____________ other processes. When that process is ready to run, then it is brought back to memory.

Back 23

Process Executing

Front 24

_______________ ___________ ______________ are fragments of memory that cannot be used to load any program as they are too small.

Back 24

Unusable Memory Fragments

Front 25

Unusable Memory Fragments may be caused by?

Back 25

Poor Memory management

Front 26

A technique in which physical memory is broken into blocks of the same size is called?

Back 26

Paging

Front 27

A technique to break memory into logical pieces where each piece represents a group of related information is called?

Back 27

Segmentation

Front 28

___________ has a fixed sized. (Paging or segment)

Back 28

Paging

Front 29

___________ can vary in size. (Paging or segment)

Back 29

Segment

Front 30

What are the two types of Fragmentation?

Back 30

Internal and External

Front 31

External or Internal Fragmentation: • Total memory space is enough for a process to fit in it • It is not contiguous so it cannot be used.

Back 31

External

Front 32

External or Internal Fragmentation: • Memory block assigned to a process is bigger • Some portion of memory is left unused as it cannot be used by another process.

Back 32

Internal

Front 33

True or False: The process reallocation is used for reallocating an entire memory used for a process not a part of memory that is allocated inside the process. Therefore, it cannot be used to solve the Internal Fragmentation problem.

Back 33

True

Front 34

What does CPU use to convert from logical address to its corresponding physical address?

Back 34

Memory Management Unit

Hint 34

MMU

Front 35

What happens if your computer has more than 4GB memory but it runs a 32 bit windows. Will the 32 bit Windows only see 4GB of memory, meaning anything over 4GB won’t be able to be used? Agree / Disagree

Back 35

Agree

Front 36

True or False: The more bits the more capacity a system can handle?

Back 36

True

Front 37

What memory is used when an OS and programs are loaded to be executed?

Back 37

RAM

Front 38

OS and programs become what when residing in a memory?

Back 38

Process

Front 39

True or False: An OS or program can run without RAM?

Back 39

False

Front 40

The process consumes memory and uses memory for writing / access data for different purposes e.g. stores its _______ data, stores contents of the _________, stores _________ data, and stores __________ data for other processes to access.

Back 40

Own file temporary shared

Front 41

Who is responsible for reducing the possibility of internal fragmentation problems?

Back 41

Programmers

Front 42

True or False: OS can solve the internal fragmentation problem by itself?

Back 42

False

Front 43

What is the main benefit of using Virtual Memory?

Back 43

Programs that are larger than physical memory can be loaded into a memory and executed

Front 44

What are the possible drawbacks of using Virtual Memory?

Back 44

When the Virtual Memory is to big and it is hard to be efficiently managed as it usually uses a hard disk to store / swap the data, the executing speed is much reduced.

Front 45

Why some pages need to be swapped out?

Back 45

They are pages that belong to a idle process (or a process that is waiting for something)

Front 46

Why do some pages remain in a memory?

Back 46

They are the pages that belong to an active process

Front 47

Can a process have some of its memory pages swapped out while the rest still remains in a memory? Yes / No

Back 47

Yes

Front 48

Why is it not good to have unnecessary swapping?

Back 48

Swapping a page that is needed by a running process will require the OS to swap that page back to the memory again wasting time and resources.

Front 49

Whichof the following is NOT true about file systems?

A) Mounting is a method to attach a file to the main file system

B) FAT file system is used in USB drive because it is simple and robust

C) NFTS is a file system used in windows

D) File system us created during the physical / low level formatting

Back 49

D

Front 50

Dividing/ marking a disk into sectors that the disk controller can read and write iscalled what?eads

Back 50

Physical Formatting

Front 51

Fillin the blanks: Cache is very _________, _________ size, and very ______ type ofstorage?

Back 51

Expensive, small, fast

Front 52

Howcan a deadlock be prevented before occurring?

Back 52

By having a resource management program

Front 53

Whichof the following is NOT considered as the benefit of multi-threading?

Back 53

No constraint by the amount of physical memory

Front 54

True or False: Thread ID is not shared by the threads in a process?

Back 54

True

Front 55

Is reallocating current processes in memory a deadlock recovery solution?

Back 55

Yes

Front 56

Whatis the main reason for processes getting into a deadlock?

Back 56

Resource Sharing

Front 57

Whatis the definition for internal fragmentation; how can it be solved?

Back 57

Memoryblock assigned to a process is bigger and some portion of memory is leftunused; can be solved by redesigning a program

Front 58

What is NOT among the benefits of Virtual Memory (VM)?

Back 58

Faster deadlock detection

Front 59

Atechnique in which physical memory is broken into blocks of the same size iscalled?

Back 59

Paging

Front 60

Whichcomponent converts logical memory addresses to physical addresses?

Back 60

MMU

Front 61

Whatis the maximum number of values which can be shown in a binary (2-bit) system?

Back 61

4

Front 62

Is itpossible to have a deadlock situation with threads?

Back 62

Yes

Front 63

Whatare the differences between multi-threads and multi-tasking?

Back 63

Multi-Threads is theability for CPU to run more than 1 thread at a time.

Multi-Tasking is theability for CPU to run more than 1 process at a time.

Front 64

What are the differences between threads and Child Processes?

Back 64

Threads: share the same address space, global variables, codes, data, files, and signal handlers with the process has created those threads. Threads are used to schedule program execution on CPU.

Child Processes has different address space from the parent process and duplicate the global variables, codes, data files and signal handlers of the parent process. Processes are used to group resources together.

Front 65

What is a Deadlock?

Back 65

Where 2 ormore competing processes are each waiting for the other to finish, so neitherof them does.

Front 66

How does a Deadlock occur?

Back 66

When 2 or more processes are trying to use the same resources

Front 67

How do you prevent a Deadlock?

Back 67

1. Usinga resource management program to ensure shared resources are not to be taken bymore than one process at a time.

2. Have a process Management program to detectevery possible deadlock situationped__3#

Front 68

True or False: In a tree-structured directory, directories and files may be shared by other users / directories?

Back 68

False

Front 69

Which of the following is the correct command to set the permission of Test.php?

A) chmod 761 Test.php

B) chmod 731 Test1.php

C) chmod 764 Test1,php

D) chmod 016 Test1.php

Back 69

c

Front 70

Prevention of legitimate use by overloading the targeted computer is called?

Back 70

Denial of Service

Front 71

Granting access control for systems resources is the responsibility of what user?

Back 71

Root User

Front 72

Identity theft at financial services company is particularly done by:

Back 72

Crimeware