操作系统选择题库答案及详解_Multiple Choice Questions 8

Multiple Choice Questions 8Question1
The type of memory that allows for very effective multiprogramming and relieves the user of memory size constraints is referred to as:
选择一个答案

a. Virtual memory √

b. Real memory

c. Main memory

d. All of the above

Question2
The replacement policy that is impossible to implement because it would require the O/S to have perfect knowledge of future events is called the:
选择一个答案

a. Least recently used (LRU) policy

b. Clock policy

c. Optimal policy √

d. None of the above

Question3
The replacement policy that chooses only among the resident pages of the process that generated the page fault in selecting a page to replace is referred to as a:
选择一个答案

a. Local replacement policy √

b. Variable replacement policy

c. Global replacement policy

d. None of the above

Question4
The concept associated with determining the number of processes that will be resident in main memory is referred to as:
选择一个答案

a. A cleaning policy

b. Load Control

c. None of the above

d. The page fault frequency √

Question5
In SVR4 and Solaris systems, the memory management scheme that manages user processes and disk I/O is called the:
选择一个答案

a. Paging system √

b. None of the above

c. Virtual memory manager

d. Kernel memory allocator

Question6
The multilevel memory management scheme implemented in Linux was designed to minimize large page tables and directories in which of the following line of processors:
选择一个答案

a. 32-bit Pentium/X86 architecture

b. 16-bit X86 architecture

c. 64-bit Alpha architecture √

d. None of the above

Question7
The Windows 2000 virtual memory manager can use page sizes ranging from:
选择一个答案

a. 64 KB to 4 GB

b. None of the above

c. 4 KB to 64 KB √

d. 4 GB to 4 TB

Question8
The situation where the processor spends most of its time swapping process pieces rather than executing instructions is called:
选择一个答案

a. Paging

b. The Principle of Locality

c. None of the above

d. Thrashing √

Question9
The situation that occurs when the desired page table entry is not found in the Translation Lookaside Buffer (TLB) is called a:
选择一个答案

a. None of the above

b. TLB hit

c. TLB miss √

d. Page fault

Question10
The real address of a word in memory is translated from the following portions of a virtual address:
选择一个答案

a. None of the above

b. Frame number and offset

c. Page number and frame number

d. Page number and offset √

Question11
Segmentation has a number of advantages to the programmer over a non-segmented address space, including:
选择一个答案

a. Sharing among processes

b. Simplifying the handling of growing data structures

c. All of the above √

d. Protection

Question12
In a combined paging/segmentation system, a user’s address space is broken up into a number of:
选择一个答案

a. Fixed-size pages, which are in turn broken down into variable-sized segments

b. Segments or pages, at the discretion of the programmer

c. Variable-sized Segments, which are in turn broken down into fixed-size pages √

d. All of the above

Question13
Sharing is achieved in a segmentation system by:
选择一个答案

a. Having a common data area that all processes can share

b. Referencing a segment in the segment tables of more than one process √

c. All of the above

d. Each process segment table having a reference to the dispatcher main memory area

Question14
A fundamental choice in the design of the memory-management portion of an O/S is:
选择一个答案

a. Whether or not to use virtual memory techniques

b. All of the above √

c. Whether to use paging, segmentation of a combination of the two

d. The algorithms employed for various aspects of memory management

Question15
The fetch policy that exploits the characteristics of most secondary memory devices, such as disks, which have seek time and rotational latency is called:
选择一个答案

a. Swapping

b. Demand paging

c. Prepaging √

d. None of the above