(Test Bank) Operating System Concepts

Silberschatz,Gagne,Galvin, 10

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Test Bank

10th Edition

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Test Bank for Operating System Concepts, The downloadable file consists of 193 pages, and the total size of the file is 2.13 MB. Purchase now only for highly discounted price.

Author(s): Silberschatz, Gagne, Galvin

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Study Note Preview

1 Chapter 1 Multiple Choice Questions 1. In what way is an operating system like a government? A) It seldom functions correctly. B) It creates an environment within which other programs can do useful work. C) It performs most useful functions by itself. D) It is always concerned primarily with the individual's needs. Ans: B Section 1.1 Difficulty: Easy 2. Which of the following components of a computer system defines the ways to use system resources to solve computing problems? A) application programs B) operating system C) computer hardware D) computer logo Ans: A Difficulty: Easy Feedback: 1.1 3. ____ operating systems are designed primarily to maximize resource utilization. A) PC B) Handheld computer C) Mainframe D) Network Ans: C Feedback: 1.1.1 Difficulty: Easy 2 4. Which of the following programs runs all the time on the computer? A) compiler B) assembler C) text editor D) kernel Ans: D Difficulty: Easy Feedback: 1.1.3 5. Which of the following will trigger an interrupt? A) kernel function B) software execution C) CPU execution D) I/O completion Ans: D Difficulty: Easy Feedback: 1.2.1 6. Which of the following is NOT secondary storage device? A) random access memory B) solid state disks C) optical disk D) magnetic tape Ans: A Difficulty: Easy Feedback: 1.2.2 7. Which of the following contains the addresses of all the service rout ines? A) page table B) interrupt vector C) system call table D) file descriptor table Ans: B Difficulty: Easy Feedback: 1.2.1.1 3 8. Which of the following stage triggers the CPU switch from user program to interrupt processing? A) I/O request B) transfer done C) interrupt signaled D) interrupt handled Ans: C Difficulty: Medium Feedback: 1.2.1.1 9. The device controller _____ an interrupt by asserting a signal on the interrupt request line. A) raises B) catches C) dispatches D) clears Ans: A Difficulty: Easy Feedback: 1.2.1.2 10. The CPU catches the interrupt and ____ it to the interrupt handler A) raises B) catches C) dispatches D) clears Ans: C Difficulty: Easy Feedback: 1.2.1.2 11. Which of the following clears the interrupt by servicing the device? A) interrupt reque st line B) interrupt -controller hardware C) interrupt vector D) interrupt service routine Ans: D Difficulty: Medium Feedback: 1.2.1.1 4 12. Which of the following is nonvolatile? A) register B) cache C) main memory D) hard -disk drive Ans: D Difficulty: Easy Feedback: 1.2.2 13. Which of the following is tertiary storage medium? A) register B) magnetic tapes C) main memory D) hard -disk drive Ans: B Difficulty: Easy Feedback: 1.2.2 14. Which of the following is the denotation of 10243 bytes? A) KB B) MB C) GB D) TB Ans: C Difficulty: Easy Feedback: 1.2.2 15. Which of the following storage medium is the slowest regarding access speed? A) cache B) solid state drive C) register D) main memory Ans: B Difficulty: Easy Feedback: 1.2.2 5 16. Which of the following is the definition of processor? A) the hardware that executes instructions B) a physical chip that contains one or more CPUs C) the basic computation unit of the CPU D) including multiple computing cores on t he same CPU Ans: B Difficulty: Medium Feedback: 1.3.2 17. Where is the location of L1 cache? A) inside CPU core B) inside processor but outside CPU core C) inside main memory D) inside registers Ans: A Difficulty: Medium Feedback: 1.3.2 18. Which of the following is loosely coupled? A) multiprocessor systems B) single -processor system C) multi -core processor D) clustered system Ans: D Difficulty: Easy Feedback: 1.3.3 19. Which of the following technology reduces the overhead for bulk data movement? A) Direct Memory Access (DMA) B) Non -uniform Memory Access (NUMA) C) Symmetric Multiprocessing (SMP) D) Storage Area Network (SAN) Ans: A Difficulty: Easy Feedback: 1.2.3 6 20. The two separate modes of operating in a system are A) supervisor mode and system mode B) kernel mode and privileged mode C) physical mode and logical mode D) user mode and kernel mode Ans: D Difficulty: Medium Feedback: 1.5.1 21. Which of the following principles is used for adding and removing items from a stack? A) first in first out (FIFO) B) last in first out (LIFO) C) random order D) round robin Ans: B Difficulty: Easy Feedback: 1.9.1 22. Which of the following principles is used for adding and removing items from a queue? A) first in first out (FIFO) B) last in first out (LIFO) C) random order D) round robin Ans: A Difficulty: Easy Feedback: 1.9.1 23. Which of the following are use d by Linux kernel as data structures? A) Lists, Stacks, and Queues B) Trees C) Hash Functions and Maps D) Bitmaps E) All of the above Ans: E Difficulty: Easy Feedback: 1.9 7 24. Which of the following computing environments place rigid time requireme nts on the operation of a processor or the flow of data? A) traditional computing B) real -time embedded system C) client -server computing D) peer -to-peer computing Ans: B Difficulty: Easy Feedback: 1.10.6 25. Which of the following statements is false? A) Mobile devices must be concerned with power consumption. B) Mobile devices can provide features that are unavailable on desktop or laptop computers. C) The difference in storage capacity between a mobile device and laptop is shrink ing. D) Mobile devices usually have fewer processing cores than a standard desktop computer. Ans: C Difficulty: Medium Feedback:1.11.2 Essay Questions 1. Computer systems can be divided into four approximate components. What are they? Ans: Hardware, operating system, application programs, and users. Feedback: 1.1 Difficulty: Easy 2. Explain why an operating system can be viewed as a resource allocator. Ans: A computer system has many resources that may be required to solve a problem: CPU time, memory space, file -storage space, I/O devices, and so on. The operating system acts as the manager of these resources. Facing numerous and possibly conflicting requests for resources, the operating system must decide how to allocate them to spec ific programs and users so that it can operate the computer system efficiently and fairly. Feedback: 1.1.2 Difficulty: Medium 8 3. Distinguish between system and application programs. Ans: System programs are not part of the kernel, but still are assoc iated with the operating system. Application programs are not associated with the operating of the system. Feedback: 1.1.3 Difficulty: Easy 4. Why is main memory not suitable for permanent program storage or backup purposes? Furthermore, what is the main disadvantage to storing information on a magnetic disk drive as opposed to main memory? Ans: Main memory is a volatile memory in that any power loss to the system will result in erasure of the data stored within that memory. While disk drives can store m ore information permanently than main memory, disk drives are significantly slower. Feedback: 1.2 Difficulty: Hard 5. Explain the purpose of an interrupt vector. Ans: The interrupt vector is merely a table of pointers to specific interrupt -handling routines. Because there are a fixed number of interrupts, this table allows for more efficient handling of the interrupts than with a general -purpose, interrupt -processing routine. Feedback: 1.2.1 Difficulty: Medium 6. What is a bootst rap program, and where is it stored? Ans: A bootstrap program is the initial program that the computer runs when it is powered up or rebooted. It initializes all aspects of the system, from CPU registers to device controllers to memory contents. Typically , it is stored in read -only memory (ROM) or electrically erasable programmable read -only memory (EEPROM), known by the general term firmware, within the computer hardware. Feedback: 1.2.1 Difficulty: Medium 7. What role do device controllers and device drivers play in a computer system? Ans: A general -purpose computer system consists of CPUs and multiple device controllers that are connected through a common bus. Each device controller is in charge of a specific type of 9 device. The device controller is responsible for moving the data between the peripheral devices that it controls and its local buffer storage. Typically, operating systems have a device driver for each device controller. This device driver understands the device controller and presents a uniform interface for the device to the rest of the operating system. Feedback: 1.2.1 Difficulty: Medium 8. Describe why direct memory access (DMA) is considered an efficient mechanism for performing I/O. Ans: DMA is efficient for moving large amounts of data between I/O devices and main memory. It is considered efficient because it removes the CPU from being responsible for transferring data. DMA instructs the device controller to move data between the devices and main memory. Feedback: 1.2.3 Difficulty: Medium 9. Describe why multi -core processing is more efficient than placing each processor on its own chip. Ans: A large reason why it is more efficient is that communication between processors on the same chip is faster than processors on se parate chips. Feedback: 1.3.2 Difficulty: Medium 10. Distinguish between uniform memory access (UMA) and non -uniform memory access (NUMA) systems. Ans: On UMA systems, accessing RAM takes the same amount of time from any CPU. On NUMA systems, accessing some parts of memory may take longer than accessing other parts of memory, thus creating a performance penalty for certain memory accesses. Feedback: 1.3.2 Difficulty: Medium 11. Why are clustered systems considered to provide high -availability service? Ans: Clustered systems are considered high -availability in that these types of systems have redundancies capable of taking over a specific process or task in the case of a failure. The redundancies are inherent due to the fact that clustered systems are composed of two or more individual systems coupled together. Feedback: 1.3.3 Difficulty: Medium 10 12. Describe the differences between physical, virtual, and logical memory. Ans: Physical memory is the memory available for machines to execute operations (i.e., cache, random access memory, etc.). Virtual memory is a method through which programs can be executed that requires space larger than that available in physical memory by using disk memory as a backing store for main memory. Logical memor y is an abstraction of the computer’s different types of memory that allows programmers and applications a simplified view of memory and frees them from concern over memory -storage limitations. Feedback: 1.4 Difficulty: Medium 13. Describe the operating system's two modes of operation. Ans: In order to ensure the proper execution of the operating system, most computer systems provide hardware support to distinguish between user mode and kernel mode. A mode bit is added to the hardware of the computer to indicate the current mode: kernel (0) or user (1). When the computer system is executing on behalf of a user application, the system is in user mode. However, when a user application requests a service from the operating system (via a system call), it mu st transition from user to kernel mode to fulfill the request. Feedback: 1.5.1 Difficulty: Medium 14. Explain cache coherency. Ans: In multiprocessor environments, two copies of the same data may reside in the local cache of each CPU. Whenever one CPU alters the data, the cache of the other CPU must receive an updated version of this data. Cache coherency involves ensuring that multiple caches store the most updated version of the stored data. Feedback: 1.8.3 Difficulty: Medium 15. Explain the differe nce between protection and security. Ans: Protection is concerned with controlling the access of processes or users to the resources of the computer system. The role of security is to defend the system from internal or external attacks. Feedback: 1.9 Difficulty: Medium 11 16. Explain the difference between singly, doubly, and circularly linked lists. Ans: A singly linked list is where each item points to its successor. A doubly linked list allows an item to point to its predecessor or successor. A circularly linked list is the where the last element points back to the first. Feedback:1.10.1 Difficulty: Easy 17. What two operating systems currently dominate mobile computing? Ans: Apple's iOS and Google's Android Feedback:1.11.2 Diffic ulty: Easy 18. Distinguish mobile computing from traditional desktop computing. Ans: Mobile computing takes place on handheld devices and tablets. Because these devices are portable and lightweight, they typically do not have the processing power and s torage capacity of desktop systems. However, features such as GPS and accelerometers have allowed mobile devices to provide functionality that is unavailable to desktop systems. Feedback: 1.11.2 Difficulty: Medium 19. Describe the compute -server and file -server types of server systems. Ans: The compute -server system provides an interface to which a client can send a request to perform an action (for example, read data from a database); in response, the server executes the action and sends back results to the client. The file -server system provides a file -system interface where clients can create, update, read, and delete files. An example of such a system is a Web server that delivers files to clients running Web browsers. Feedback: 1. 10.3 Diffi culty: Medium 12 20. Describe cloud computing. Ans: Cloud computing is a type of computing that delivers computing, storage, and application services across a network. Cloud computing often uses virtualization to provide its functionality. There are many different types of cloud environments, as well as services offered. Cloud computing may be either public, private, or a hybrid of the two. Additionally, cloud computing may offer applications, platforms, or system infrastructures. Feedback:1. 10.7 Difficulty: Hard True/False Questions 1. There is no universally accepted definition of an operating system. Ans: True Feedback:1.1.3 Difficulty: Medium 2. Solid state disks are generally faster than magnetic disks. Ans: True Feedback: 1. 5.5 Difficulty: Easy 3. Solid state disks are considered volatile storage. Ans: False Feedback: 1.2.2 Difficulty: Medium 4. Virtually all modern operating systems provide support for SMP Ans: True Feedback: 1.3.2 Difficulty: Easy 13 5. MapReduce is a system which allows for parallel processing of data across nodes in the cluster. Ans: Yes Feedback:1.4 Difficulty: Medium 6. A system call runs in kernel mode only. Ans: Yes Feedback:1.4.2 Difficulty: Easy 7. A system call is triggered by hardware. Ans: False Feedback: 1.5.1 Difficulty: Easy 8. The process runs with effective UID all the time until the proces s is stopped. Ans: No Feedback:1.6 Difficulty: Medium 9. On UNIX, t he setuid attribute on a program causes that program to run with the user ID of the current user’s ID. Ans: No Feedback:1.6 Difficulty: Medium 10. VMware is a virtual machine manager when it manages guest operating systems. Ans: Yes Feedback:1.7 Difficulty: Easy 14 11. Skype uses a hybrid peer -to-peer approach. Ans: Yes Feedback:1.10.4 Difficulty: Easy 12. Processors for most mobile devices run at a slower speed than a processor in a desktop PC. Ans: True Feedback: 1. 10.2 Difficulty: Medium 1 Chapter 2 Multiple Choice Questions 1. Which of the following statements is incorrect? A) An operating system provides an environment for the execution of programs. B) An operating system manages system resources. C) Operating systems provide both command line as well as graphical user interfaces. D) Operating systems must provide both protection and security. Ans: C Feedback: 2.1 Difficulty: Easy 2. Which of the following is an inter -process communication that requires two processes share memory ? A) message passing B) shared memory C) socket communication D) all of the above Ans: B Feedback: 2.1 Difficulty: Easy 3. Which of the following is not an operating system service? A) program execution B) I/O operation C) protection and security D) graphical user interface Ans: D Feedback: 2.2 Difficulty: Easy 2 4. Which of the following is a user interface where human fingers slide across the screen or press buttons to select choices? A) touch screen B) graphical user interface C) command line D) voice control Ans: A Feedback: 2.2.1 Difficulty: Easy 5. Which of the following is not a type of command interpreter? A) Bourne shell B) C shell C) Korn shell D) KDE or GNOME Ans: D Feedback: 2.2.1 Difficulty: Easy 6. _____ provide(s) an interface to the services provided by an operating system. A) Shared memory B) System calls C) Simulators D) Communication Ans: B Feedback: 2.3 Difficulty: Medium 7. Which of the following is the only gateway between user space and kernel space? A) user interface B) system call C) operating system D) hardware drivers Ans: B Feedback: 2.3.2 Difficulty: Medium 3 8. What is the relationship between library call open() and open() system call ? A) open() system call is part of open() B) open() system call in an alternate version of open() C) open() is a predecessor version of open() system call D) open() invokes open() system call to get service from operating system Ans: D Feedback: 2.3.2 Difficulty: Medium 9. What category of syst em call includes the ones for process creation of and termination? A) process control B) file management C) device management D) protection Ans: A Feedback: 2.3.3.1 Difficulty: Easy 10. Which of the following defines the view of the operating system seen by most users? A) application and system programs B) system calls C) device drivers D) library calls Ans: A Feedback: 2.4 Difficulty: Easy 11. The Windows CreateProcess() system call creates a new process. What is the equivalent system call in UNIX ? A) NTCreateProcess() B) process() C) fork() D) getpid() Ans: C Feedback: 2. 3.3.1 Difficulty: Easy 4 12. The close() system call in UNIX is used to close a file. What is the equivalent system call in Windows ? A) CloseHandle() B) close() C) CloseFile() D) Exit() Ans: A Feedback: 2. 3.3.1 Difficulty: Easy 13. The Windows CreateFile() system call is used to create a file. What is the equivalent system call in UNIX ? A) ioctl() B) open() C) fork() D) createfile() Ans: B Feedback: 2. 3.3.1 Diffi culty: Easy 14. The ________ provides a portion of the system call interface for UNIX and Linux. A) POSIX B) Java C) Standard C library D) Standard API Ans: C Feedback: 2. 3.3.1 Difficulty: Medium 15. A message -passing model is ____. A) easier to implement than a shared memory model for intercomputer communication B) faster than the shared memory model C) a network protocol, and does not apply to operating systems D) only useful for small simple o perating systems Ans: A Feedback: 2. 3.3.5 Difficulty: Medium 5 16. Microkernels use _____ for communication. A) message passing B) shared memory C) system calls D) virtualization Ans: A Feedback: 2. 8.3 Difficulty: Easy 17. Android runs Java programs _____________ A) in the Android RunTime (ART) virtual machine. B) natively. C) in the Java virtual machine. D) Android does not run Java programs. Ans: A Feedback: 2. 8.5.2 Difficulty: Medium 18. ______ is a mobile operating system designed for the iPhone and iPad. A) Mac OS X B) Android C) UNIX D) iOS Ans: D Feedback: 2. 8.5.1 Difficulty: Medium 19. Which of the following operating system structure is the one for MS -DOS? A) monolithic structure B) layered structure C) microkernel D) modular approach Ans: A Feedback: 2.8.1 Difficulty: Easy 6 20. Which of the following inter -process communication is used in microkernel? A) message passing B) shared memory C) socket communication D) all of the above Ans: A Feedback: 2.8 .3 Difficulty: Medium 21. Which of the following operating system structure is the one for Mach OS? A) monolithic structure B) layered structure C) microkernel D) modular approach Ans: C Feedback: 2.8.3 Difficulty: Easy 22. Which of the following operating system structure involves using loadable kernel module in design? A) monolithic structure B) layered structure C) microkernel D) modular approach Ans: D Feedback: 2.8.4 Difficulty: Easy 23. Which of the following is a m uch more restricted, or even closed, system to developers than others? A) Linux B) Mac OS X C) iOS D) Android Ans: C Feedback: 2.8.5.1 Difficulty: Easy 7 24. Which of the following is the correct program type for GRUB in Linux and Unix systems? A) bootstrap program B) compiler program C) binder program D) system utility Ans: A Feedback: 2.9.2 Difficulty: Easy 25. When a process fails, the operating system t akes a ________ which can then be probed by a debugger for failure analysis? A) core dump B) crash dump C) capture of network statistic information D) capture of CPU usage information Ans: A Feedback: 2.10.1 Difficulty: Easy Essay Questions 1. There are two different ways that commands can be processed by a command interpreter. One way is to allow the command interpreter to contain the code needed to execute the command. The other way is to implement the commands through system programs. Compare and c ontrast the two approaches. Ans: In the first approach, upon the user issuing a command, the interpreter jumps to the appropriate section of code, executes the command, and returns control back to the user. In the second approach, the interpreter loads the appropriate program into memory along with the appropriate arguments. The advantage of the first method is speed and overall simplicity. The disadvantage to this technique is that new commands require rewriting the interpreter program which, after a nu mber of modifications, may get complicated, messy, or too large. The advantage to the second method is that new commands can be added without altering the command interpreter. The disadvantage is reduced speed and the clumsiness of passing parameters from the interpreter to the system program. Feedback: 2.2 Difficulty: Hard 8 2. Describe the relationship between an API, the system -call interface, and the operating system. Ans: The system -call interface of a programming language serves as a link to system calls made available by the operating system. This interface intercepts function calls in the API and invokes the necessary system call within the operating system. Thus, most of the details of the operating -system interface are hidden from the prog rammer by the API and are managed by the run-time support library. Feedback: 2.3 Difficulty: Hard 3. Describe three general methods used to pass parameters to the operating system during system calls. Ans: The simplest approach is to pass the paramete rs in registers. In some cases, there may be more parameters than registers. In these cases, the parameters are generally stored in a block, or table, of memory, and the address of the block is passed as a parameter in a register. Parameters can also be pl aced, or pushed, onto the stack by the program and popped off the stack by the operating system. Feedback: 2.3 Difficulty: Medium 4. Describe some requirements, or goals, when designing an operating system. Ans: Requirements can be divided into user and system goals. Users desire a system that is convenient to use, easy to learn, and to use, reliable, safe, and fast. System goals are defined by those people who must design, create, maintain, and operate the system: The system should be easy to design, implement, and maintain; it should be flexible, reliable, error -free, and efficient. Feedback: 2. 7.1 Difficulty: Medium 5. What are the advantages of using a higher -level language to implement an operating system? Ans: The code can be written faster, is more compact, and is easier to understand and debug. In addition, improvements in compiler technology will improve the generated code for the entire operating system by simple recompilation. Finally, an operating system is far easier to port — to move to some other hardware — if it is written in a higher -level language. Feedback: 2. 7.3 Difficulty: Medium 9 6. What are the advantages and disadvantages of using a microkernel approach? Ans: One benefit of the microkernel approach is ease of ext ending the operating system. All new services are added to user space and consequently do not require modification of the kernel. The microkernel also provides more security and reliability, since most services are running as user — rather than kernel — processes. Unfortunately, microkernels can suffer from performance decreases due to increased system function overhead. Feedback: 2. 8.3 Difficulty: Medium 7. Explain why a modular kernel may be the best of the current operating system design techniques. Ans: The modular approach combines the benefits of both the layered and microkernel design techniques. In a modular design, the kernel needs only to have the capability to perform the required functions and know how to communicate between modules. However , if more functionality is required in the kernel, then the user can dynamically load modules into the kernel. The kernel can have sections with well -defined, protected interfaces, a desirable property found in layered systems. More flexibility can be achi eved by allowing the modules to communicate with one another. Feedback: 2. 8.4 Difficulty: Hard 8. Describe how Mac OS X is considered a hybrid system. Ans: Primarily because the kernel environment is a blend of the Mach microkernel and BSD UNIX (which i s closer to a monolithic kernel.) Feedback: 2. 8.5.1 Difficulty: Medium 9. Describe how Android uses a unique virtual machine for running Java programs. Ans: The Android RunTime (ART) virtual machine is designed specifically for Android and has been optimized for mobile devices with limited memory and CPU processing capabilities. Feedback: 2. 8.5.2 Difficulty: Medium 10 True/False Questions 1. Application programmers typically use an API rather than directory invoking system calls. Ans: True Feedback: 2.3 Difficulty: Easy 2. In general, Windows system calls have longer, more descriptive names and UNIX system calls use shorter, less descriptive names. Ans: True Feedback: 2.4 Difficulty: Easy 3. Many operating system merge I/O devices and files into a combined file because of the similarity of system calls for each. Ans: True Feedback: 2.4.3 Difficulty: Medium 4. Applications compiled on one operating system can be directly executable on other operating systems due to common structure. Ans: False Feedback: 2.6 Difficulty: Easy 5. One important principle is the separation of policy from mechanism. Ans: True Feedback: 2.7.2 Difficulty: Easy 11 6. Mac OS X is a hybrid system consisting of both the Mach microkernel and BSD UNIX. Ans: True Feedback: 2. 8.5.1 Difficulty: Medium 7. iOS is open source, Android is closed source. Ans: False Feedback: 2. 8.5.1 Difficulty: Medium 8. iOS and Android combine different structures, resulting in hybrid systems tha t address performance, security, and usability issues. Ans: True Feedback: 2.8.5 Difficulty: Easy