Exam 3

Question 1

MMU

Answer 1

Memory Management Unit

Question 2

TLB

Answer 2

Translation Lookaside Buffer

Question 3

FIFO

Answer 3

First In, First Out

Question 4

DMA

Answer 4

Direct Memory Access

Question 5

RAID

Answer 5

Redundant Array of Inexpensive Disks

Question 6

dynamic relocation

Answer 6

moving things around in memory dynamically

Question 7

swapping

Answer 7

Memory allocation changes as processes come into memory and leave it

Question 8

memory compaction

Answer 8

“burping” the holes out from between the pages

Question 9

coalescing

Answer 9

combining adjacent holes in RAM into one

Question 10

virtual address

Answer 10

this can be added to the block’s base to get the physical address

Question 11

page frame

Answer 11

block in REAL memory that may hold a page

Question 12

page fault

Answer 12

an error that occurs when a block of memory that has not been stored in RAM has been attempted to be accessed

Question 13

page table

Answer 13

An array with subscripts that correspond to blocks of virtual memory. The destination block of real memory is the value of that subscript. So array[virtualMemoryBlock] would hold the actual physical RAM address

Question 14

translation lookaside buffer(TLB)

Answer 14

a small hardware device that maps virtual address to physical addresses without going through the page table

Question 15

dirty page frame

Answer 15

when a page in RAM and a page on the disk differ (variables changed, etc)(One that has been modified)

Question 16

working set

Answer 16

the set of pages that have been accessed in the k most recent

Question 17

thrashing

Answer 17

excessive page files

Question 18

cylinders

Answer 18

vertical sections of the piece of the disk

Question 19

sectors

Answer 19

pieces of the track

Question 20

cycle stealing

Answer 20

disk drives have higher priority than the CPU and will steal cycles from it on the bus

Question 21

tracks

Answer 21

a piece of the surface of the disk

Question 22

striping

Answer 22

when a file is spread across multiple disks

Question 23

cylinder skew

Answer 23

starting point for next larger track is offset from previous track, to account for time required for read/write head to move so it doesn’t have to wait for a complete revolution for start point to come back again

Question 24

elevator algorithm

Answer 24

goes up to the top, and down towards the bottom, picking processes as it goes up and down

Question 25

pits and lands

Answer 25

burning mountains and valleys on the surface of the cd to represent 1s and 0s

Question 26

mickey

Answer 26

unit of mouse movement

Question 27

pixel

Answer 27

a picture element

Question 28

i-node

Answer 28

an index node, stores the attributes and disk block locations of the filesystem object's data

Question 29

in order to support multiprogramming with dynamic relocation, computer designers added what two special registers?

Answer 29

Base register and the limit register

Question 30

what data structures may be used to keep track of which sections of memory are used by a process and whech sections are holes

Answer 30

Bitmap, Linked List

Question 31

how would these structures be used to coalesce memory

Answer 31

bitmap-there's nothing to do | linked list-take two nodes and merge them into one

Question 32

what is the difference between a page and a page frame?

Answer 32

page - virtual page | page frame- where it goes in real memory

Question 33

who or what deals with page faults

Answer 33

OS

Question 34

what is stored in a page table

Answer 34

the mapping between virtual and physical addresses

Question 35

Why is a translation lookaside often used?

Answer 35

speeds up the process of checking to see if a page has been loaded in memory

Question 36

what is an inverted page table and when might it be used

Answer 36

When subscripts and values are swapped. Subscripts = page frames and values = page

Question 37

what is the formula that determines the optimal page size?

Answer 37

p=sqrt(2se)

Question 38

what are the two types of backing stores

Answer 38

executable image | page file

Question 39

what is a platter

Answer 39

a circular disk - a track on top and a track on bottom

Question 40

a track

Answer 40

a ring of sectors on a disk

Question 41

a cylinder

Answer 41

a vertical group of platters

Question 42

a sector

Answer 42

a section of space in a track

Question 43

what is seek time

Answer 43

how much time it takes the read/write head to get to its destination

Question 44

what is rotation time or rotational delay

Answer 44

how long it takes for a sector to make it all the way around to its origin point

Question 45

describe the 6 RAID levels

Answer 45

0-striping; no parity; purely parallel and for speed 5-duplication across drives with parity bit, which is also shared by other drives so it's shared uniformly 6-duplicated parity bits

Question 46

the time required to read or write a disk block is determined by what three factors?

Answer 46

seek time rotation delay transfer time

Question 47

explain how 24-bit RGB representation is used to render "true color"

Answer 47

One byte for Red, one for Green, one for Blue

Question 48

what would a system manager implement disk quotas?

Answer 48

keep anyone from hogging space

Question 49

what two techniques are often used to track the free blocks on a disk drive

Answer 49

bitmaps | link list