Question 1

Consider paging address translation by direct mapping. Given the base address, a, in the page table origin register, virtual address v = (p, d)  and an entry p' (in the page table starting at address a)  for the page frame corresponding to virtual page p, what is the real address corresponding to v?

Accepted Answer

A)   p' * d
B)   p' concatenated with d
C)   (a + p)  * d
D)   (a + p)  concatenated with d

Question 2

In a combined segmentation/paging system, ________.

Accepted Answer

A)   all the pages of a segment must be in main memory at once
B)   virtual memory pages that are contiguous in virtual memory must be contiguous in main memory
C)   segments typically are arranged across multiple pages
D)   all of the above

Question 3

In a block mapping system, suppose that a is a base address stored in the block map table origin register and that the block map table for the process with base address a contains the real address b' for the start of virtual block b in main memory and the real address d' for the start of virtual block d in main memory. What is the real address of virtual address v = (b, d) ?

Accepted Answer

A)   b' + d
B)   d' + b
C)   a + b'
D)   a + d' A

Question 4

Using copy-on-write to ensure that two processes do not interfere with each other when modifying pages ________.

Accepted Answer

A)   slows down process creation
B)   improves performance when processes modify a significant amount of shared data during execution
C)   both a and b
D)   none of the above

Question 5

A process given append-only access to a segment may __________.

Accepted Answer

A)   read information from the segment
B)   write information to the segment
C)   pass program control to instructions in that segment for execution on a processor
D)   write additional information to the end of the segment, but not modify existing information

Question 6

Systems that use dynamic address translation exhibit ________-the property that contiguous addresses in a process's virtual address space need not be contiguous in physical memory.

Accepted Answer

A)   transparent contiguity
B)   dynamic contiguity
C)   artificial contiguity
D)   static contiguity

Question 7

In a paging system, ________.

Accepted Answer

A)   a page frame is always larger than an incoming page
B)   a page frame is always smaller than the incoming page
C)   given the virtual memory address v = (p, d)  , where page p is in page frame p' and the fixed page size is ps, then the real memory address of v is (p' + d)  * ps
D)   when a process references a page that is not in main memory, the operating system loads the nonresident page into memory from secondary storage

Question 8

In a virtual memory system , ________.

Accepted Answer

A)   each virtual address space is much smaller than the real address space
B)   determining how to map virtual addresses to physical addresses is of great importance
C)   MMUs convert physical addresses to virtual addresses during execution
D)   when the system is ready to run a process, the system loads the process's code and data from main memory into cache

Question 9

To improve performance, a designer can attempt to reduce the number of collisions that occur in an inverted page table by ________.

Accepted Answer

A)   increasing the size of the inverted page table
B)   increasing the range of the hash function using a hash anchor table
C)   both a and b
D)   none of the above

Question 10

Page sharing ________.

Accepted Answer

A)   increases the amount of main memory required for a group of processes to run efficiently
B)   decreases a system's degree of multiprogramming
C)   does not allow modifiable procedures from being used by more than one process at the same time
D)   none of the above

Question 11

In multilevel page tables, __________ is reduced compared to direct-mapped tables when process's use only a small number of pages.

Accepted Answer

A)   internal fragmentation
B)   external fragmentation
C)   memory fragmentation
D)   table fragmentation D

Question 12

Sharing __________ using segmentation can simplify memory management compared to paging.

Accepted Answer

A)   an object
B)   reentrant code
C)   a dynamic array
D)   all of the above

Question 13

Under direct/associative mapping, ________.

Accepted Answer

A)   accessing the associative memory is slower than accessing the main memory
B)   the number of entries in the TLB needs to be large to achieve good performance
C)   the page table entries maintained in the TLB typically correspond only to the more-recently referenced pages
D)   better performance can be achieved than under a complete associative mapping C

Question 14

In an inverted page table, the number of PTEs that must be stored in main memory is proportional to _________.

Accepted Answer

A)   the size of physical memory
B)   the size of virtual memory
C)   the size of a virtual address space
D)   the size of the process

Question 15

All of a process's segments ________.

Accepted Answer

A)   must consist of contiguous memory locations
B)   must be the same size
C)   must be placed adjacent to one another in main memory
D)   are maintained in main memory during execution

Question 16

The overhead incurred by multilevel page address translation is __________.

Accepted Answer

A)   significant due to increased table fragmentation
B)   significant due to additional memory references
C)   offset by caches and TLBs
D)   none of the above

Question 17

In a system that uses segmentation address translation by direct mapping, ________.

Accepted Answer

A)   the segment map table origin register contains the segment map table's base address value
B)   the mapping mechanism uses the information stored in the segment map table to translate the virtual address to a physical address
C)   the sum of the segment map table's base address and the segment number determines the location of the segment's map table entry
D)   all of the above

Question 18

In a paged and segmented system using combined associative/direct mapping, ________.

Accepted Answer

A)   missing-segment faults, segment-overflow exceptions and segment-protection exceptions can never occur during dynamic address translation
B)   the more tables a system maintains in main memory, the fewer processes it can support
C)   the associative memory is unimportant to the efficient operation of the dynamic address translation
D)   the benefit of maintaining only a few of the tables in main memory at any one time is that address translation proceeds faster at execution time

Question 19

Inverted page tables use __________ to map virtual pages to PTEs.

Accepted Answer

A)   arrays
B)   hash functions
C)   linked lists
D)   chaining mechanisms

Question 20

An associative mapping __________.

Accepted Answer

A)   stores the entire page table in content-addressed associative memory
B)   provides better performance than direct mapping
C)   is too expensive to implement
D)   all of the above

Exam 10: Memory Management and Address Translation in Operating Systems

Consider paging address translation by direct mapping. Given the base address, a, in the page table origin register, virtual address v = (p, d) and an entry p' (in the page table starting at address a) for the page frame corresponding to virtual page p, what is the real address corresponding to v?

Correct Answer
verified

In a combined segmentation/paging system, ________.

Correct Answer
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Correct Answer
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A

Using copy-on-write to ensure that two processes do not interfere with each other when modifying pages ________.

Correct Answer
verified

A process given append-only access to a segment may __________.

Correct Answer
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Systems that use dynamic address translation exhibit ________-the property that contiguous addresses in a process's virtual address space need not be contiguous in physical memory.

Correct Answer
verified

In a paging system, ________.

Correct Answer
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In a virtual memory system , ________.

Correct Answer
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To improve performance, a designer can attempt to reduce the number of collisions that occur in an inverted page table by ________.

Correct Answer
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Page sharing ________.

Correct Answer
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In multilevel page tables, __________ is reduced compared to direct-mapped tables when process's use only a small number of pages.

Correct Answer
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D

Sharing __________ using segmentation can simplify memory management compared to paging.

Correct Answer
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Under direct/associative mapping, ________.

Correct Answer
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C

In an inverted page table, the number of PTEs that must be stored in main memory is proportional to _________.

Correct Answer
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All of a process's segments ________.

Correct Answer
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The overhead incurred by multilevel page address translation is __________.

Correct Answer
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In a system that uses segmentation address translation by direct mapping, ________.

Correct Answer
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In a paged and segmented system using combined associative/direct mapping, ________.

Correct Answer
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Inverted page tables use __________ to map virtual pages to PTEs.

Correct Answer
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An associative mapping __________.

Correct Answer
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Exam 10: Memory Management and Address Translation in Operating Systems

Consider paging address translation by direct mapping. Given the base address, a, in the page table origin register, virtual address v = (p, d) and an entry p' (in the page table starting at address a) for the page frame corresponding to virtual page p, what is the real address corresponding to v?

Correct AnswerverifiedShow Answer

In a combined segmentation/paging system, ________.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

Using copy-on-write to ensure that two processes do not interfere with each other when modifying pages ________.

Correct AnswerverifiedShow Answer

A process given append-only access to a segment may __________.

Correct AnswerverifiedShow Answer

Systems that use dynamic address translation exhibit ________-the property that contiguous addresses in a process's virtual address space need not be contiguous in physical memory.

Correct AnswerverifiedShow Answer

In a paging system, ________.

Correct AnswerverifiedShow Answer

In a virtual memory system , ________.

Correct AnswerverifiedShow Answer

To improve performance, a designer can attempt to reduce the number of collisions that occur in an inverted page table by ________.

Correct AnswerverifiedShow Answer

Page sharing ________.

Correct AnswerverifiedShow Answer

In multilevel page tables, __________ is reduced compared to direct-mapped tables when process's use only a small number of pages.

Correct AnswerverifiedD

Sharing __________ using segmentation can simplify memory management compared to paging.

Correct AnswerverifiedShow Answer

Under direct/associative mapping, ________.

Correct AnswerverifiedC

In an inverted page table, the number of PTEs that must be stored in main memory is proportional to _________.

Correct AnswerverifiedShow Answer

All of a process's segments ________.

Correct AnswerverifiedShow Answer

The overhead incurred by multilevel page address translation is __________.

Correct AnswerverifiedShow Answer

In a system that uses segmentation address translation by direct mapping, ________.

Correct AnswerverifiedShow Answer

In a paged and segmented system using combined associative/direct mapping, ________.

Correct AnswerverifiedShow Answer

Inverted page tables use __________ to map virtual pages to PTEs.

Correct AnswerverifiedShow Answer

An associative mapping __________.

Correct AnswerverifiedShow Answer

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A

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D

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C

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