Chap 8

Question 1

The size of virtual storage is limited by the actual number of main storage locations.

Answer 1

FALSE

Question 2

The addresses a program may use to reference memory are distinguished from the addresses the memory system uses to identify physical storage sites.

Answer 2

TRUE

Question 3

Most of the memory management issues confronting the operating system designer are in the are of paging when segmentation is combined with paging.

Answer 3

TRUE

Question 4

Segmentation is not visible to the programmer.

Answer 4

FALSE

Question 5

The placement policy determines where in real memory a process piece is to reside.

Answer 5

TRUE

Question 6

Virtual memory allows for very effective multiprogramming and relieves the user of the unnecessarily tight constraints of main memory.

Answer 6

TRUE

Question 7

The principle of locality states that program and data references within a process do not tend to cluster.

Answer 7

FALSE

Question 8

The smaller the page size, the greater the amount of internal fragmentation.

Answer 8

FALSE

Question 9

The design issue of page size is related to the size of the physical main memory and program size.

Answer 9

TRUE

Question 10

Segments may be of unequal, indeed dynamic, size.

Answer 10

TRUE

Question 11

The page currently stored in a frame may still be replaced even when the page is locked.

Answer 11

FALSE

Question 12

One way to counter the potential performance problems of a variable-allocation global scope policy is to use page buffering.

Answer 12

TRUE

Question 13

The PFF policy evaluates the working set of a process at sampling instances based on elapsed virtual time.

Answer 13

FALSE

Question 14

A precleaning policy writes modified pages before their page frames are needed so that pages can be written out in batches.

Answer 14

TRUE

Question 15

UNIX is intended to be machine-independent; therefore its memory management scheme will vary from one system to the next.

Answer 15

TRUE

Question 16

The address of a storage location in main memory is the _________.

Answer 16

real address

Question 17

__________ is the virtual storage assigned to a process.

Answer 17

virtual address space

Question 18

_________ is the range of memory addresses available to a process.

Answer 18

address space

Question 19

The _______ structure indexes page table entries by frame number rather than by virtual page number.

Answer 19

inverted page table

Question 20

The _______ states the process that owns the page.

Answer 20

process identifier

Question 21

A __________ is issued if a desired page is not in main memory.

Answer 21

page fault

Question 22

___________ allows the programmer to view memory as consisting of multiple address spaces.

Answer 22

segmentation

Question 23

_________ is transparent to the programmer and eliminates external fragmentation providing efficient use of main memory.

Answer 23

paging

Question 24

The _________ determines when a page should be brought into main memory.

Answer 24

fetch policy

Question 25

With ________ pages other than the one demanded by a page fault are brought in.

Answer 25

prepaging

Question 26

The _______ policy results in the fewest number of page faults.

Answer 26

optimal

Question 27

A ________ chooses only among the resident pages of the process that generated the page fault in selecting a page to replace.

Answer 27

local replacement policy

Question 28

The ________ algorithm requires a use bit to be associated with each page in memory.

Answer 28

page fault frequency

Question 29

________ is where modified process pages can be written out at the time of replacement, or a precleaning policy can be used, which clusters the output activity by writing out a number of pages at once.

Answer 29

Cleaning policy

Question 30

_________ is the concept associated with determining the number of processes that will be resident in main memory.

Answer 30

Load control

Question 31

The address assigned to a location in virtual memory to allow that location to be accessed as though it were part of main memory is the ___________.

Answer 31

virtual address

Question 32

_________ is the storage allocation scheme in which secondary memory can be addressed as though it were part of main memory.

Answer 32

virtual memory

Question 33

The size of virtual storage is limited by the addressing scheme of the computer system and by the amount of ___________ available

Answer 33

secondary memory

Question 34

The ______ policy treats the page frames allocated to a process as a circular buffer and pages are removed in a round robin style.

Answer 34

FIFO

Question 35

The portion of a process that is actually in main memory at any time is defined to be the ____________ of the process.

Answer 35

resident set

Question 36

A __________ policy allows the number of page frames allocated to a process to be varied over the lifetime of the process.

Answer 36

variable allocation

Question 37

Because a process executes only in main memory, that memory is referred to as ______________.

Answer 37

real memory

Question 38

When the system spends most of its time swapping pieces rather than executing instructions it leads to a condition known as ____________.

Answer 38

thrashing

Question 39

To overcome the problem of doubling the memory access time, most virtual memory schemes make use of a special high-speed cache for page table entries called a ____________.

Answer 39

translation lookaside buffer

Question 40

The technique where the processor is equipped with hardware that allows it to interrogate simultaneously a number of TLB entries to determine if there is a match on page number is referred to as ______________.

Answer 40

associative mapping

Question 41

With _________, a page is brought into main memory only when a reference is made to a location on that page.

Answer 41

demand paging

Question 42

The ___________ policy replaces the page in memory that has not been referenced for the longest time.

Answer 42

least recently used

Question 43

The __________ provides a virtual memory capability that allocates page frames in main memory to processes and also allocates page frames to disk block buffers.

Answer 43

paging system

Question 44

Linux makes use of a three-level page table structure consisting of the following types of tables: page directory, page table, and ___________.

Answer 44

page middle directory

Question 45

In SVR4 and Solaris systems, the memory management scheme that manages memory allocation for the kernel is called the ____________.

Answer 45

kernel memory allocator

Question 46

_________ allows the programmer to view memory as consisting of multiple address spaces. Select one: a. Paging b. Locality c. Segmentation d. Resident set management

Answer 46

c

Question 47

With _________ pages other than the one demanded by a page fault are brought in. Select one: a. slab allocation b. thrashing c. hashing d. prepaging

Answer 47

d

Question 48

_________ is the concept associated with determining the number of processes that will be resident in main memory. Select one: a. Virtual memory manager b. Page fault frequency c. LRU policy d. Load Control

Answer 48

d

Question 49

The _________ algorithm requires a use bit to be associated with each page in memory. Select one: a. page placement b. working set c. VSWS d. page fault frequency

Answer 49

b