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1、Operating Systems, 5 th ed. Test Bank Chapter 8 Page of 8 1 Chapter 8 Virtual Memory True / False Questions: 1.T / F In a system employing a memory management strategy that doesnt require an entire process to be in main memory at one time, the portion of a process that is actually in main memory at
2、any given time is defined to be the resident set of the process. 在一个使用一个不需要 整个的程序以一个次是在主存中的存储器管理系统中, 程序的部分实际上是在任何的给定时间是在主记忆中定 义当程序的居留组。 ANS: T 2.T / F The condition known as thrashing occurs when the majority of the processes in main memory require repetitive blocking on a single shared I/O device i
3、n the system.在一个系统中，当 大量的主存中的进程要求重复阻断一个单独共享的I/O 设备的情况称之为系统抖动 ANS: F (processor spends most of its time swapping rather than executing) 错。是处理器花费大量 时间不断进行交换块，而不是去执行指令 3.T / F The modify (M) bit is a control bit in a page table entry that indicates whether the contents of the corresponding page have be
4、en altered since the page was last loaded into memory. 修改位（ M ）是一个控制位，他表示相应页的内容从上一次装入主存中到现在是否已经发生变化。 ANS: T对 4.T / F A Page Fault occurs when the desired page table entry is not found in the Translation Lookaside Buffer (TLB).一个页错误的发生是在转移后备缓冲器中不存在所需要的页 ANS: F (when the desired page is not found in m
5、ain memory)错误，是发生在主存中不存在所需页表 5.T / F One of the advantages to the programmer of virtual memory using segmentation is that it simplifies the handling of growing data structures by allowing the segment to grow or shrink as necessary. 对程序员而言，使用虚拟内存的一个优点是它简化了处理增加的数据结构，这是通过允许段进行必 要的增加或者缩小的操作 ANS: T对 6.T
6、/ F In a combined paging/segmentation system, a users address space is broken up into a number of fixed-size pages, which in turn are broken up into a number of segments.在一个段页复用 的系统中，一个用户的地址空间被划分程序多固定大小的页，这些也有被划分成许多段 ANS: F (opposite segments/pages)错误的，先分成段，在进行分页 7.T / F To achieve sharing in a segm
7、entation system, it is possible for a segment to be referenced in the segment tables of more than one process. 为了实现在一个段系统的共享，一个段有 可能再多共和进程的段表中被使用 Operating Systems, 5 th ed. Test Bank Chapter 8 Page of 8 2 ANS: T 8.T / F Linux is an example of an operating system that does not provide virtual memory
8、.linux 就是一个没有提供虚拟内存的操作系统。 ANS: F (early UNIX or MS-DOS)错，早期的unix 和 msdos 9.T / F The fetch policy determines when a page should be brought into main memory.读取策略确定 一页何时取入主存 ANS: T对 10. T / F The Least Recently Used (LRU) replacement policy replaces the page in memory that has been referenced most rec
9、ently.LRU替换策略是替换最常用的页 ANS: F错 (that has not been referenced in the longest amount of time) .LRU替换策略是替换距离 当前时间最远的页 11. T / F A global replacement policy considers all unlocked pages in main memory as candidates for replacement, regardless of which process owns a particular page.全局替换策略是把主存中所有的 未被锁定的页都
10、作为替换的候选页，而不管他们属于那个进程 ANS: T对 12. T / F In a precleaning policy, modified pages are written to secondary memory once they have been selected for replacement.在预约式清除策略中，被修改的页一旦被选中作为替换，将会被写入辅存中 ANS: F (written before that, so they can be batched)错 13. T / F SVR4 and Solaris systems use two separate sche
11、mes for memory management, one for user processes and disk I/O, and another for kernel memory allocation.SVR4和 Solaris系统使用了两套独 立的内存管理方案，一个是对用户进程和磁盘的I/O 接口，而另一个则是为微内核内存分配管理 ANS: T 14. T / F Linux makes use of a two-level page table structure, consisting of a page directory and a page table.linux利用两级分
12、页结构组成页目录和页表 ANS: F (three-level, also a page middle directory)错误，应用了三级，还包括页中间目录 15. T / F Every W2K user process sees a separate 32-bit address space, allowing 4 GB of memory per process.每一个 win2000 的用户进程看到的是一个独立的32 位地址空间，每个进程允许有4GB存储空间 ANS: T对 Operating Systems, 5 th ed. Test Bank Chapter 8 Page of
13、 8 3 Multiple Choice Questions: 1.The type of memory that allows for very effective multiprogramming and relieves the user of memory size constraints is referred to as:哪一种类型的存储器允许更有效的多道程序设计，并且解除了 用户与主存大小之间的约束 a.Real memory 真实内存 b.Virtual memory虚拟内存 c.Main memory 主存 d.All of the above三者皆是 ANS: B 2.Th
14、e situation where the processor spends most of its time swapping process pieces rather than executing instructions is called: 处理器花费大量时间不断进行交换块，而不是去执行指令的现象称为 a.Paging 分页 b.The Principle of Locality局部性原理 c.Thrashing系统抖动 d.None of the above都不是 ANS: C 3.The situation that occurs when the desired page ta
15、ble entry is not found in the Translation Lookaside Buffer (TLB) is called a: 在转移后备缓冲器中不存在所需要的页的情况叫做 a.TLB miss TLB 未命中 b.TLB hit TLB命中 c.Page fault 页错误 d.None of the above都不是 ANS: A 4.The real address of a word in memory is translated from the following portions of a virtual address: 一个字的在主存中的真实地址从
16、下列虚拟地址的哪一部分转送的 a.Page number and frame number页号和帧号 b.Page number and offset页号和偏移地址 c.Frame number and offset帧号和偏移地址 d.None of the above都不是 ANS: B 5.Segmentation has a number of advantages to the programmer over a non-segmented address space, including:分段组织和非段式地址空间想必有很多优点，包括 Operating Systems, 5 th ed. Test Bank Chapter 8 Page of 8 4 a.Simplifying the handli
