Test 2 Part 1

Question 1

Size of the cache in blocks?

Answer 1

Bytes / Bytes per block

Question 2

How many writes occur?

Answer 2

Every time it gives a variable a value it is writing to it, so multiply the for loops

Question 3

Capacity Miss?

Answer 3

Capacity misses occur when the amount of data referenced by a program exceeds the capacity of the cache

Question 4

Cold Miss

Answer 4

This happens when an object is given a value

Question 5

Synchronous Events are Caused by?

Answer 5

instruction currently being executed

Question 6

Asynchronous events are caused by

Answer 6

Something outside of the program

Question 7

Trap

Answer 7

Is intentional and requested by running program

Question 8

Fault

Answer 8

Is unintentional and recoverable

Question 9

Abort

Answer 9

Unintentional and unrecoverable

Question 10

Fork outputs must include

Answer 10

Both the parent and child processes

Question 11

What does wait(NULL) do?

Answer 11

Waits for child process to terminate

Question 12

What does flush() do?

Answer 12

Flushs input after it is printed

Question 13

Size of points array

Answer 13

(64*64)/bytes per block

Question 14

hardware multiprocessing

Answer 14

System Timer: At regular intervals, the system timer goes off which causes control to be transferred to the OS scheduler.

Question 15

Software multiprocessing

Answer 15

Schedular: Chooses a process to run from a set of ready to run processes.

Question 16

SIGCHLD

Answer 16

The SIGCHLD signal is sent to a process when a child processterminates, is interrupted, or resumes after being interrupted.

Question 17

What process reaps the parent process

Answer 17

the shell

Question 18

what process reaps the child process

Answer 18

init process

Question 19

What process reaps the grandchild

Answer 19

process the child process

Question 20

What process executes the handler

Answer 20

The process that receives the SIGCHLD process

Question 21

Where is a.out executed?

Answer 21

foreground, & makes it run in the background

Question 22

What are the two primary system functions that the shell causes when a.out is ran, and what do they do

Answer 22

Fork: Creates child process
Exec: Called by child to run a different program

Question 23

What prevents the shell from redisplaying the shell prompt right away rather than after a few seconds when the program completes?

Answer 23

the shell has a loop to wait for the child process to terminate

Question 24

how is a builtin cmd handled differently by the shell

Answer 24

it doesn’t run either fork or exec

Question 25

what signal will be sent to the shell when ctrlC is pressed?
what signal will be sent to the loopforever process?

Answer 25

Sends a SIGINT & SIGCHLD
SIGINT

Question 26

What is Internal Fragmentation

Answer 26

This is space that isn’t used for the payload (headers, footers, padding) inside an allocated block (fixed block)

Question 27

What is external fragmentation

Answer 27

When there is enough heap memory but not enough space in a single free block

Question 28

What is memory utilization?

Answer 28

Memory utilization is the % of heap that is used for payloads, fragmentation decreases this.

Question 29

Define throughput

Answer 29

Number of requests per unit of time

Question 30

Which free list provides a higher throughput?

Answer 30

Explicit, it uses pointer which is faster

Question 31

Difference between explicit and implicit free list?

Answer 31

Explicit only contains free blocks
Implicit contains free blocks and allocated blocks

Question 32

Define virtual memory

Answer 32

Mechanism that allows process to share primary memory so they are executed concurrently (execution times overlay)

Question 33

what is a page fault?

Answer 33

address is good but page is not, in DRAM

Question 34

what is a seg fault?

Answer 34

address is bad

Question 35

Coalescing is performed to avoid?

Answer 35

External fragmentation

Question 36

Why is the footer important?

Answer 36

Helps find previous block to coalesce, only needed on free blocks.

Question 37

Physical Page

Answer 37

Same as page frame, same size as VP (in bytes)

Question 38

Values that are initialized already when ready to use are stored

Answer 38

in the data section

Question 39

Memory pointed to by a pointer is stored

Answer 39

in the heap

Question 40

Misc variables are stored in the

Answer 40

stack

Question 41

Breakdown physical block

Answer 41

ppn[ct], ppo[ct, ci, c0(0)]

Question 42

Breakdown virtual block

Answer 42

vpn[index(15), tag], vpo