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

Multiple Choice Questions 1Question1The general role of an operating system is to:选择一个答案a. Provide a set of services to system usersb. Manage files for application programsc. Act as an interface between various computersd. None of the aboveFeedback:A. 为系统用户提供一系列服务B. 为应用程序管理文件(这显然不是)C. 作为多台计算机间的接口(应该是CPU与硬件之间的接口)D. errorQuestion2Information that must be saved prior to the processor transferring control to the interrupt handler routine includes:选择一个答案a. Program Status Word (PSW) & Contents of processor registersb. Program Status Word (PSW)c. None of the aboved. Program Status Word (PSW) & Location of next instructionFeedback:D.程序状态字和下个指令的位置 P14Question3One accepted method of dealing with multiple interrupts is to:选择一个答案a. Service them in round-robin fashionb. Disable all interrupts except those of highest priorityc. None of the aboved. Define priorities for the interruptsFeedback:处理多个中断的方法 P18The first is to disable interrupts while an interrupt is being processed.A second approach is to define priorities for interrupts and to allow an interrupt of higher priority to cause a lower-priority interrupt handler to be interrupted.A. 轮循服务(显然错误)B. 只服务优先级高的，忽视优先级低的C. errorD. 为这些中断定义优先级Question4In a uniprocessor system(单处理器系统), multiprogramming(多道程序设计) increases processor efficiency by:选择一个答案a. Taking advantage of time wasted by long wait interrupt handling b. Eliminating all idle processor cyclesc. All of the aboved. Increasing processor speedFeedback:A.利用等待中断的时间 P18Question5As one proceeds down the memory hierarchy (i.e., from inboard memory to offline storage), the following condition(s) apply:选择一个答案a. Decreasing capacityb. Increasing access timec. All of the aboved. Increasing cost per bitFeedback:A.容量 B.访问时间 C.errorD.价格 Question6Small, fast memory located between the processor and main memory is called选择一个答案a. WORM memoryb. CD-RW memoryc. None of the aboved. Cache memoryFeedback:D.存储器的层次结构由上至下依次为：寄存器(processer)，高速缓存，主存储器(memory)，磁盘，磁带Question7When a new block of data is written into cache memory, the following determines which cache location the block will occupy:选择一个答案a. None of the aboveb. Cache sizec. Block sized. Write policyFeedback:Nothing will change.高速缓冲存储器设计：cache size，block size,mapping function,replacement algorithm,write policy.Question8The four main structural elements of a computer system are:选择一个答案a. None of the aboveb. Processor, Registers, Main Memory & System Busc. Processor, Main Memory, I/O Modules & System Busd. Processor, Registers, I/O Modules & Main MemoryFeedback:计算机有四个主要的结构化部件：处理器、主存储器、输入/输出模块、系统总线 P6Question9The two basic types of processor registers are:选择一个答案a. User-visible and Control/Status registersb. Control and Status registersc. User-visible and user-invisible registersd. None of the aboveFeedback:用户可见寄存器：数据寄存器、地址寄存器、索引寄存器、段指针、栈指针控制和状态寄存器：程序计数器PC、指令寄存器IRQuestion10Address registers may contain选择一个答案a. Partial memory addressesb. Memory addresses of datac. Memory addresses of instructionsd. All of the aboveFeedback:A.辅存地址B.数据的主存储器地址C.指令的主存储器地址Question11A Control/Status register that contains the address of the next instruction to be fetched is called the:选择一个答案a. Program Counter (PC)b. All of the abovec. Instruction Register (IR)d. Program Status Word (PSW)Feedback:A. Program counter (PC) = Address of instructionC. Instruction register (IR) = Instruction being executedD. Program Status Word (PSW) = contains status informationQuestion12The two basic steps used by the processor in instruction processing are:选择一个答案a. None of the aboveb. Fetch and Instruction cyclesc. Fetch and Execute cyclesd. Instruction and Execute cyclesFeedback:In its simplest form, instruction processing consists of two steps: The processor reads (fetches) instructions from memory one at a time and executes each instruction. P9Question13A fetched instruction is normally loaded into the:选择一个答案a. Accumulator (AC)b. None of the abovec. Instruction Register (IR)d. Program Counter (PC)Feedback:Instruction register (IR) = Instruction being executedA. Accumulator (AC) = Temporary storage 临时存储体Question14A common class of interrupts is选择一个答案a. Programb. I/Oc. Timerd. All of the aboveFeedback:Classes of interrupts:Program, Timer, I/O, Hardware failureQuestion15When an external device becomes ready to be serviced by the processor, the device sends this type of signal to the processor:选择一个答案a. Handler signalb. None of the abovec. Interrupt signald. Halt signalFeedback:请求中断信号Multiple Choice Questions 2Question1A primary objective of an operating system is:选择一个答案a. Ability to evolveb. Conveniencec. Efficiencyd. All of the aboveFeedback:操作系统的三个主要目标：方便，有效，扩展的能力Question2The paging system in a memory management system provides for dynamic mapping between a virtual address used in a program and:选择一个答案a. A real address in a programb. None of the abovec. A virtual address in main memoryd. A real address in main memoryFeedback：The paging system provides for a dynamic mapping between the virtual address used in the program and a real address, or physical address, in mainmemory. P51Question3Relative to information protection and security in computer systems, access control typically refers to:选择一个答案a. The flow of data within the systemb. Proving that security mechanisms perform according to specificationc. Regulating user and process access to various aspects of the systemd. None of the aboveFeedback：调节用户和进程对系统方方面面的访问权限Question4A common problem with full-featured operating systems, due to their size and difficulty of the tasks they address, is:选择一个答案a. Sub-par performanceb. Chronically late in deliveryc. All of the aboved. Latent bugs that show up in the fieldFeedback：一个功能完善的操作系统的大小和它所处理任务的困难性，导致了四个让人遗憾但又普遍存在的问题：操作系统在交付使用时习惯性表现出落后系统有潜在的错误总是难以达到期望的性能不可能开发出既复杂又不易受各种安全性攻击的操作系统P 54Question5A technique in which a process, executing an application, is divided into threads that can run concurrently is called:选择一个答案a. None of the aboveb. Multithreadingc. Symmetric multiprocessing (SMP)d. MultiprocessingFeedback：Multithreading is a technique in which a process, executing an application, is divided into threads that can run concurrently. P56Question6WIN2K supports several types of user applications, including:选择一个答案a. Linuxb. System 10c. WIN32d. None of the aboveFeedback：NothingQuestion7Key to the success of Linux has been its character as a free software package available under the auspices of the:选择一个答案a. Berkeley Software Distributionb. Free Software Foundationc. World Wide Web Consortiumd. None of the aboveFeedback：Key to the success of Linux has been the availability of free software packagesunder the auspices of the Free Software Foundation (FSF). P70Question8The operating system provides many types of services to end-users, programmers and system designers, including:选择一个答案a. Built-in user applicationsb. All of the abovec. Relational database capabilities with the internal file systemd. Error detection and responseFeedback：the OS typically provides services in the following areas： Program development Program execution Access to I/O devices Controlled access to files System access Error detection and response AccountingQuestion9The operating system is unusual in its role as a control mechanism, in that:选择一个答案a. It runs on a special processor, completely separated from the rest of the systemb. It never relinquishes control of the system processorc. None of the aboved. It frequently relinquishes control of the system processor and must depend on the processor to regain control of the system Feedback： The OS functions in the same way as ordinary computer software; that is, it is a program or suite of programs executed by the processor. The OS frequently relinquishes control and must depend on the processor to allow it to regain control. P40Question10Operating systems must evolve over time because选择一个答案a. Users will only purchase software that has a current copyright dateb. New hardware is designed and implemented in the computer systemc. All of the aboved. Hardware must be replaced when it failsFeedback：计算机需要不断发展的原因：硬件升级和新型硬件的出现、新的服务、纠正错误P 40/41Question11A major problem with early serial processing systems was:选择一个答案a. Inability to get hardcopy outputb. Setup timec. Lack of input devicesd. All of the aboveFeedback：调度和准备时间Question12An example of a hardware feature that is desirable in a batch-processing system is选择一个答案a. None of the aboveb. A completely accessible memory areac. Large clock cyclesd. Privileged instructionsFeedback：内存保护、定时器、特权指令、中断Question13A computer hardware feature that is vital to the effective operation of a multiprogramming operating system is:选择一个答案a. Very large memoryb. Multiple processorsc. I/O interrupts and DMAd. All of the aboveFeedback：支持I/O中断和直接存储器访问Question14The principle objective of a time sharing, multiprogramming system is to选择一个答案a. Maximize processor useb. None of the abovec. Provide exclusive access to hardwared. Maximize response timeFeedback：批处理多道程序设计是为了充分使用处理器，分时多道程序设计是为了减小响应时间Question15Which of the following major line of computer system development created problems in timing and synchronization that contributed to the development of the concept of the process?选择一个答案a. Multiprogramming batch operation systemsb. Real time transaction systemsc. All of the aboved. Time sharing systemsFeedback：Three major lines of computer system development created problems in timing and synchronization that contributed to the development of the concept of the process: multiprogramming batch operation, time sharing, and real-time transaction systems.Question16Which of the following major line of computer system development created problems in timing and synchronization that contributed to the development of the concept of the process?选择一个答案a. Multiprogramming batch operation systemsb. Real time transaction systemsc. Time sharing systemsd. All of the aboveMultiple Choice Questions 3Question1The behavior of a processor can be characterized by examining:选择一个答案a. Multiple process tracesb. A single process tracec. All of the aboved. The interleaving of the process tracesFeedback:We can characterize behavior of the processor by showing how the traces of the various processes are interleaved. P81Question2The Process Image element that contains the modifiable part of the user space is called the:选择一个答案a. User Programb. None of the abovec. System Stackd. Process Control BlockFeedback:User data.Question3The processor execution mode that user programs typically execute in is referred to as:选择一个答案a. System modeb. None of the abovec. User moded. Kernel modeFeedback:用户态。System mode = kernel modeQuestion4One step in the procedure for creating a new process involves:选择一个答案a. Assigning a unique identifierb. All of the abovec. Allocating space for the processd. Initializing the process control blockFeedback：P99 12345Question5A process switch may occur when the system encounters an interrupt condition, such as that generated by a:选择一个答案a. All of the aboveb. Trapc. Supervisor calld. Memory faultFeedback：中断：时钟中断、I/O中断、内存失效陷阱系统调用Question6In the Process Based O/S:选择一个答案a. None of the aboveb. Major kernel functions are organized as separate functionsc. The User Process Image includes a kernel stackd. O/S code and data are contained in the shared address spaceFeedback：主要的内核函数被组织成独立的进程 P103Question7In a typical UNIX system, the element of the process image that contains the processor status information is the:选择一个答案a. All of the aboveb. System-level contextc. Register contextd. User-level contextFeedback：处理器状态信息保存在寄存器上下文中Question8The behavior of an individual process can be characterized by examining:选择一个答案a. The interleaving of the process tracesb. All of the abovec. Multiple process tracesd. A single process traceFeedback:独立的进程：单独的进程轨迹Question9The basic Two-State Process Model defines two possible states for a process in relationship to the processor:选择一个答案a. Running and Executingb. Running and Not Runningc. None of the aboved. Executing and WaitingFeedback:运行和非运行两种状态Question10There are a number of conditions that can lead to process termination, including:选择一个答案a. Normal completionb. Parent terminationc. All of the aboved. Bounds violationFeedback：P 85Question11In the Five-State Process Model, the following represents a valid state transition:选择一个答案a. All of the aboveb. New - Blockedc. New - Runningd. Running - BlockedFeedback：Null - New / New - Ready / Ready - Running / Running - Exit / Running - Ready / Running - Blocked / Blocked - Ready / Ready - Exit / Blocked - ExitQuestion12In a Process Model that implements two suspend states, a valid state transition is represented by:选择一个答案a. Ready - Ready/Suspendb. Running - Ready/Suspendc. Ready/Suspend - Readyd. All of the aboveFeedback:P 89/90Question13The scheduling strategy where each process in the queue is given a certain amount of time, in turn, to execute and then returned to the queue, unless blocked is referred to as:选择一个答案a. Round-Robinb. Prioritizationc. All of the aboved. LIFOFeedback:Round-Robin 轮循 P84Question14A Memory Table is an O/S control structure that is used by the O/S to:选择一个答案a. Manage I/O devicesb. Provide information about system filesc. None of the aboved. Manage processesFeedback：Memory tables are used to keep track of both main (real) and secondary(virtual) memory.Question15The Process Image element that contains the collection of attributes needed by the O/S to control a particular process is called the:选择一个答案a. User Datab. System Stackc. None of the aboved. Process Control BlockFeedback：进程控制块Multiple Choice Questions 4Question1The concept of a process in an operating system embodies two primary characteristics, one of which is:选择一个答案a. None of the aboveb. Resource ownershipc. Symmetric multiprocessingd. MultithreadingFeedback:资源所有权、调度/执行Question2Early operating systems that were designed with little concern about structure are typically referred to as:选择一个答案a. Monolithic operating systemsb. Kernel operating systemsc. All of the aboved. Layered operating systemsFeedback：单体结构的操作系统Question3A benefit of the microkernel organization is:选择一个答案a. Flexibilityb. All of the abovec. Portabilityd. ExtensibilityFeedback：一致接口、可扩展性、灵活性、可移植性、可靠性、分布式系统支持、对面向对象操作系统的支持Question4In low-level microkernel memory management, an example of an operation that can support external paging and virtual memory management is the:选择一个答案a. Map operationb. Flush operationc. Grant operationd. All of the aboveFeedback：三个微内核操作支持内核外的分页和虚存管理授权、映射、刷新 P129Question5In a W2K system, the state that a thread enters when it has been unblocked and the resource for which it has been blocked is not yet available is called the:选择一个答案a. Waiting stateb. Standby statec. None of the aboved. Transition stateFeedback：过渡态Question6In a Solaris system, a User-Level Thread (ULT) that enters the active state is assigned to a:选择一个答案a. Heavy-Weight Process (HWP)b. Light-Weight Process (LWP)c. None of the aboved. Kernel threadFeedback：轻量级进程Question7In a Linux system, when a new process is cloned, the two processes share the same:选择一个答案a. Process identifierb. Virtual memoryc. task_struct data structured. All of the aboveFeedback：克隆后共享同一个虚存Question8An example of a system that implements a single process with multiple threads is:选择一个答案a. WIN 2000b. All of the abovec. Solarisd. JavaFeedback：P 113Question9Which of the following is true regarding the relationship between processes and threads:选择一个答案a. It takes less time to switch between two different processes than to switch between two threads within the same processb. It takes far less time to create a new thread in an existing process than to create a new process c. It takes less time to terminate a process than a threadd. All of the aboveFeedback：NothingQuestion10The basic thread operation related to the change in thread state that occurs when a thread needs to wait for an event is referred to as the:选择一个答案a. Unblock operationb. None of the abovec. Spawn operation 派生d. Block operationFeedback：显然阻塞Question11One of the disadvantages of User-Level Threads (ULTs) compared to Kernel-Level Threads (KLTs) is:选择一个答案a. All of the aboveb. When a ULT executes a system call, all threads in the process are blocked c. Scheduling is application specificd. Thread switching does not require kernel mode privilegesFeedback：P 119/120Question12In the Linux O/S, multiple threads may be created and executed within a single process. This is an example of the following Thread-to-Process relationship:选择一个答案a. 1:Mb. 1:1c. None of the aboved. M:NFeedback：Thread ：Process = M ：1Question13The computer system category where a single processor executes a single instruction stream to operate on data stored in a single memory is called:选择一个答案a. Single Instruction Multiple Data (SIMD) streamb. None of the abovec. Single Instruction