Deck 9: Memory Management in Operating Systems: Segmentation, Paging, and Strategies for Efficiency

Question 1

________, while plentiful, is slower than other forms of storage and not suitable for running programs.

A) main memory
B) cache
C) secondary storage
D) All of the above

Answer 1

secondary storage

Question 2

Which of the following statements is false?

A) Secondary storage cannot be referenced directly by a processor.
B) Some systems cannot afford the overhead of virtual memory.
C) Real memory management is unimportant in today's systems.
D) Most of today's systems are virtual memory systems.

Answer 2

Real memory management is unimportant in today's systems.

Question 3

Operating systems can divide main memory into portions called ________ so that one process cannot overwrite another's memory, either inadvertently or maliciously.

A) sections
B) partitions
C) modules
D) regions

Answer 3

partitions

Question 4

A memory manager's primary function is ________.

A) to determine how to allocate available memory
B) to determine how to respond to changes in a process's memory usage
C) to interact with special memory management hardware
D) all of the above

Question 5

According to ________, many processes that access data and instructions once are likely to access them again in the future.

A) access patterns
B) Moore's Law
C) spatial locality
D) temporal locality

Question 6

Going from lower to higher levels in the memory hierarchy, ________.

A) storage access time decreases
B) storage cost per bit increases
C) storage capacity increases
D) both a and b

Question 7

________ strategies determine which pieces of data to remove from main memory to free space for a new process.

A) Fetch
B) Placement
C) Replacement
D) both a and c

Question 8

________ strategies attempt to load a piece of program or data into memory before it is referenced.

A) Demand fetch
B) Anticipatory fetch
C) First-fit placement
D) Next-fit placement

Question 9

In general, the overhead incurred by ________ allocation is outweighed by the advantages of being able to store more processes in main memory at the same time.

A) contiguous
B) noncontiguous
C) fragment
D) segment

Question 10

Noncontiguous memory allocation splits programs into blocks of memory called ________ that can be loaded into nonadjacent "holes" in main memory.

A) pages
B) partitions
C) frames
D) segments

Question 11

Before the advent of ________, programmers wrote all the code necessary to implement a particular application, including the highly detailed machine-level input/output instructions.

A) an IOCS
B) a BIOS
C) object-oriented programming languages
D) memory management

Question 12

________ is a technique that involves breaking a program into logical segments and keeping only the currently needed segment in memory at any one time.

A) Caching
B) Swapping
C) Dynamic programming
D) Creating overlays

Question 13

________ can be thought of as a modern operating system-controlled version of overlays.

A) IOCS
B) Virtual memory
C) Caching
D) Noncontiguous memory

Question 14

A(n) ________ can be used in single-user contiguous memory allocation systems to prevent programs from damaging the operating system's memory.

A) lock
B) protection bit
C) boundary register
D) semaphore

Question 15

To allow programs to access and execute operating system instructions, operating systems provide ________.

A) the executive mode of execution
B) system calls
C) memory protection keys
D) both a and b

Question 16

________ was an early innovation that helped decrease the amount time the computer wasted between jobs.

A) Batch processing
B) Interactive computing
C) Single-user contiguous memory allocation
D) both a and b

Question 17

A ________ reads and executes the control-language statements that define each job as well as helps prepare the system for the next job.

A) boundary register
B) batch processor
C) single-stream batch processor
D) job stream processor

Question 18

Under fixed-partition multiprogramming, ________ occurs when a memory partition is larger than the memory and data of the process currently loaded into it.

A) compaction
B) garbage collection
C) internal fragmentation
D) external fragmentation

Question 19

In a partitioned memory environment, the single boundary register is replaced by the ________ and ________ registers which delimit the upper and lower boundaries of a partition, respectively.

A) base, limit
B) limit, base
C) high, low
D) low, high

Question 20

________-partition multiprogramming allows a process to occupy only as much space as needed in an attempt to prevent ________ fragmentation.

A) Variable, internal
B) Fixed, internal
C) Variable, external
D) Fixed, external

Question 21

To maximize the use of available space, ________ combines adjacent holes in memory, while ________ relocates all occupied areas of memory to one end of main memory, leaving a single large free memory hole instead of numerous small holes.

A) internal fragmentation, external fragmentation
B) compaction, coalescing
C) coalescing, compaction
D) variable-partition multiprogramming, fixed-partition multiprogramming

Question 22

The significant overhead associated with ________ makes it largely unsuitable for use in real-time systems.

A) coalescing
B) compaction
C) memory protection
D) fixed-partition multiprogramming

Question 23

Under a ________ placement strategy, the system places an incoming job in the hole in main memory in which it fits most tightly.

A) first-fit
B) next-fit
C) best-fit
D) worst-fit

Question 24

The ________ placement strategy allows the system to make a placement decision quickly and generally incurs the least amount of overhead of the various placement strategies.

A) best-fit
B) worst-fit
C) first-fit
D) none of the above

Question 25

________ temporarily removes a process from main memory to allow another process to make use of the system's resources.

A) Swapping
B) Switching
C) Compacting
D) Coalescing