Memory Management

Question 1

Which of the following is a benefit of allowing a program that is only partially in memory to
execute?
A) Programs can be written to use more memory than is available in physical memory.
B) CPU utilization and throughput is increased.
C) Less I/O is needed to load or swap each user program into memory.
D) All of the above

Answer 1

D- ALL OF THE ABOVE

Question 2

In systems that support virtual memory, ____.
A) virtual memory is separated from logical memory.
B) virtual memory is separated from physical memory.
C) physical memory is separated from secondary storage.
D) physical memory is separated from logical memory

Answer 2

D- PHYSICAL MEMORY IS SEPARATED FROM LOGICAL MEMORY

Question 3

The vfork() system call in UNIX ____.
A) allows the child process to use the address space of the parent
B) uses copy-on-write with the fork() call
C) is not intended to be used when the child process calls exec() immediately after creation
D) duplicates all pages that are modified by the child process

Answer 3

A- ALLOWS THE CHILD PROCESS TO USE THE ADDRESS SPACE OF THE PARENT

Question 4

Belady’s anomaly states that ____.
A) giving more memory to a process will improve its performance
B) as the number of allocated frames increases, the page-fault rate may decrease for all page
replacement algorithms
C) for some page replacement algorithms, the page-fault rate may decrease as the number of
allocated frames increases
D) for some page replacement algorithms, the page-fault rate may increase as the number of
allocated frames increases

Answer 4

D- FOR SOME PAGE REPLACEMENT ALGORITHMS, THE PAGE-FAULT RATE MAY INCREASE AS THE NUMBER OF ALLOCATED FRAMES INCREASES

Question 5

Optimal page replacement ____.
A) is the page-replacement algorithm most often implemented
B) is used mostly for comparison with other page-replacement schemes
C) can suffer from Belady’s anomaly
D) requires that the system keep track of previously used pages

Answer 5

B- IS USED MOSTLY FOR COMPARISON WITH OTHER PAGE-REPLACEMENT SCHEMES

Question 6

The \_\_\_\_\_ allocation algorithm allocates available memory to each process according to its
size.
A) equal
B) global
C) proportional
D) slab

Answer 6

C- PROPORTIONAL

Question 7

The \_\_\_\_ is the number of entries in the TLB multiplied by the page size.
A) TLB cache
B) page resolution
C) TLB reach
D) hit ratio

Answer 7

C- TLB REACH

Question 8

. ________ allows the parent and child processes to initially share the same pages, but when
either process modifies a page, a copy of the shared page is created.
A) copy-on-write
B) zero-fill-on-demand
C) memory-mapped
D) virtual memory fork

Answer 8

A- COPY-ON-WRITE

Question 9

. \_\_\_\_\_ is the algorithm implemented on most systems.
A) FIFO
B) Least frequently used
C) Most frequently used
D) LRU

Answer 9

D- LRU

Question 10

. \_\_\_\_\_ occurs when a process spends more time paging than executing.
A) Thrashing
B) Memory-mapping
C) Demand paging
D) Swapping

Answer 10

A- THRASHING

Question 11

Windows uses a local page replacement policy _____.
A) when a process exceeds its working set minimum
B) when a process exceeds its working set maximum
C) when the system undergoes automatic working set trimming
D) under all circumstances

Answer 11

B- WHEN A PROCESS EXCEEDS ITS WORKING SET MAXIMUM

Question 12

Which of the following statements is false with regard to Solaris memory management?
A) The speed at which pages are examined (the scanrate) is constant.
B) The pageout process only runs if the number of free pages is less than lotsfree.
C) An LRU approximation algorithm is employed.
D) Pages selected for replacement may be reclaimed before being placed on the free list.

Answer 12

A- THE SPEED AT WHICH PAGES ARE EXAMINED (THE SCANRATE) IS CONSTANT

Question 13

Which of the following statements is false with regard to allocating kernel memory?
A) Slab allocation does not suffer from fragmentation.
B) Adjacent segments can be combined into one larger segment with the buddy system.
C) Because the kernel requests memory of varying sizes, some of which may be quite small, the
system does not have to be concerned about wasting memory

Answer 13

C

Question 14

The \_\_\_\_\_ is an approximation of a program's locality.
A) locality model
B) working set
C) page fault frequency
D) page replacement algorithm

Answer 14

B- WORKING SET

Question 15

\_\_\_\_\_\_ allows a portion of a virtual address space to be logically associated with a file.
A) Memory-mapping
B) Shared memory
C) Slab allocation
D) Locality of reference

Answer 15

A- MEMORY MAPPING

Question 16

Systems in which memory access times vary significantly are known as \_\_\_\_\_\_\_\_\_\_.
A) memory-mapped I/O
B) demand-paged memory
C) non-uniform memory access
D) copy-on-write memory

Answer 16

C- NON-UNIFORM MEMORY ACCESS

Question 17

Which of the following is considered a benefit when using the slab allocator?
A) Memory is allocated using a simple power-of-2 allocator.
B) It allows kernel code and data to be efficiently paged.
C) It allows larger segments to be combined using coalescing.
D) There is no memory fragmentation.

Answer 17

D- THERE IS NO MEMORY FRAGMENTATION