OSG key

Question #10 (1 point) How many categories can be the I/O devices roughly divided? 1 2 3 4

2

A ____ is a group of related records that contains information to be used by specific application programs to generate reports. A. Field B. Record group C. File D. Directory

A

A ____ is a portion of a process that can run independently A. thread B. program C. Mini-process D. subprocess

A

An arrival message causes the system to create a new thread to handle this message. This new thread is call______ A. Pop-up B. Upcall C. Activator D. Distributed

A

In order to implement mutual exclusion on a critical resource for competing processes, only one program at a time should be allowed: A. In the critical region of the program B. To perform message passing C. To exhibit cooperation D. None of the other choices

A

OS Win32 use system call_____, while OS Unix use system call______ to create a new process A. CreateProcess; fork B. fork, CreateProcess C. copy, CreateProcess D. CreateProcess; copy

A

Operating system abstraction supports the ability to have ______ operation even when there is only one CPU available A. pseudoparallelism B. parallel C. multiple D. None of the other choices

A

Question #1 (1 point) The Linking technique that allows the file to appear in more than one directory are: Hard link Symbolic link Both hard link and symbolic link Soft link

A

Question #11 (1 point) In order to implement mutual exclusion on a critical resource for competing processes, only one program at a time should be allowed: A.In the critical region of the program B.To perform message passing C.To exhibit cooperation D.None of the other choices

A

Question #12 (1 point) Imagine that a certain printer can print 400 characters per second and that the time to write a character to the printer's output register is so short it can be ignored. If to run this printer using interrupt-driven I/O and each character printed requires an interrupt that takes 50 µsec all-in to service. How many percent of the CPU does the interrupt overhead cost? 2% of the CPU 98% of the CPU 4% of the CPU 96% of the CPU

A

Question #15 (1 point) Which of the following statements is incorrect about I/O using DMA? a, DMA is software solution to speed up data transfer between I/O device and memory b, DMA helps free up the CPU during the I/O to do other work c, DMA helps reduce the number of interrupts d, None of the other choices

A

Question #16 (1 point) What is asynchronous transfer in principles of I/O software? The CPU starts the transfer and goes off to do something else until the interrupt arrives The user program starts system call to transfer and automatically suspended until the data are available in the buffer The user process makes system call and goes to sleep until other process it wakes up None of the other choices

A

Question #17 (1 point) When an external device becomes ready to be serviced by the processor, the device sends this signal to the processor. This signal is called: a, Interrupt signal b, Halt signal c, Handler signal d, None of the other choices

A

Question #21 (1 point) What is the table where its entry contains the memory address of Interrupt service routine a, Interrupt vector table b, Interrupt table c, Address table d, Address lines table

A

Question #25 (1 point) What is the purpose of CPU scheduling algorithms? a, Pick one of the ready processes to run next b, Put to sleep and wake up processes in an efficient manner c, Allocate memory to the processes in a fair and efficient way d, None of the other choices

A

Question #27 (1 point) What happens when a thread calls Down (S) when it wants to enter its critical section, where S is a binary semaphore set to 1? a, The thread is allowed to enter its critical section and S is decremented. b, The thread is blocked and added to a queue of waiting threads. c, The semaphore is set to 2. d, None of the other choices

A

Question #29 (1 point) Which mechanism is implemented by writing to the log file with the purpose of file system management and optimization? a, Journaling File Systems b, Log-Structured File Systems c, Virtual File Systems d, None of the other choices

A

Question #3 (1 point) Which is not a goal of a scheduling algorithm for all systems? A.Response time B.Policy enforcement C.Balance D.Fairness

A

Question #34 (1 point) Semaphores that are initialized to 1 and used for two or more processes to ensure only one can enter its critical section at the same time are called: a, Binary semaphores b, Integer semaphores c, Counter semaphores d, None of the other choices

A

Question #36 (1 point) If i-node contains 10 direct addresses and all disk blocks are 1024 KB, what is largest possible file a, 10 MB b, 10 GB c, 1 GB d, None of the other choices

A

Question #4 (1 point) An interrupt that leaves the machine in well-defined state is called a(n) ______ a, Precise interrupt b, Imprecise interrupt c, Required interrupt d, Disappointed interrupt

A

Question #9 (1 point) The I/O technique where the processor busy waits for an I/O operation to complete is called: Programmed I/O Interrupt-driven I/O Direct Memory Access (DMA) None of the other choices

A

Which of the following conditions must be held to provide good solution for mutual exclusion? A. No two processes simultaneously in critical region B. No assumptions made about speeds or numbers of CPUs C. No process running outside its critical region may block another process D. No process must wait forever to enter its critical region E. All of the other choices

A

Which of the following conditions that causes the processes to be terminated, when processes have done their work? A. Normal exit (voluntary ) B. Error exit (voluntary) C. Fatal error (involuntary) D. Killed by another process (involuntary)

A

Which of the following statements is a hardware solution to the critical region problem? A. TSL B. Shared memory C. Semaphore D. None of the other choices

A

A entry of the Process table is called: A. Process management block B. Process control block C. Process check block D. All of the other choices

B

A process where no concurrency inside process; everything happens sequentially is called : A. Random access process B. Sequential process C. Sequential access process D. None of the other choices

B

Critical Region (Section) concept used in interprocess communication is: A. A part of shared memory B. A part of the program where the shared memory is accessed C. None of the other choices D. A part of shared data

B

How many percent of the CPU time is wasted, when a computer system has enough room to hold two program and these programs are idle waiting for I/O half the time? A. 50% B. 25% C. 75% D. None of the other choices

B

In terms of main memory efficiency the method of "Backing up pages dynamically" in comparison with the method of "Paging to a static swap area" is A. Better B. Worse C. Equal D. Nearly equal

B

Many computer users and some operating systems call subdirectories ____. A. Folders B. Files C. Volumes D. Databases

B

Question #1 (1 point) Which of the following is correct about Shortest Job First scheduling algorithm? A. Avoid Starvation B.Minimize average waiting time C.Avoid Starvation and Minimize average waiting time D.None of the other choices

B

Question #1 5(1 point) Which of the following is not a CPU scheduling criterion? A.CPU utilization B.Burst time C.Throughput D.Response time

B

Question #16 (1 point) Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the average waiting time for SJF (Shortest job first) scheduling. Ignore process switching overhead. A.14 minutes B.8 minutes C.6 minutes D.18.8 minutes

B

Question #17 (1 point) Which of the following synchronization mechanisms does not rely on busy-waiting? A.Lock variables B.Strict alternation C.Peterson's algorithm D.Semaphores

B

Question #20 (1 point) The first-come, first-served (FCFS) algorithm is fine for most ____ systems a,Interactive b,Batch c,Real time d,Multiuser

B

Question #24 (1 point) The File Manager writes the volume name and other descriptive information on an easy-to-access place on each unit: ____ of the CD or DVD The outermost part The innermost part Immediately following the master file directory Stored at the beginning of the volume

B

Question #26 (1 point) In the hierarchical structure for managing I/O, which layer is closest to the hardware? a, Device drivers b, Device-independent OS software c, Interrupt handlers d, None of the other choices

B

Question #30 (1 point) How many level of scheduling are used in computer a,1 b,2 c,3 d,4

B

Question #30 (1 point) ____ allocation allows files to use any storage space available on the disk. a, Contiguous storage b, Noncontiguous storage c, Fragmented storage d, Add-on storage

B

Question #32 (1 point) A entry of the Process table is called: a,Process management block b,Process control block c,Process check block d,All of the other choices

B

Question #33 (1 point) Which method is used to implement files with file's size larger than 2 GB in UNIX V7? a, i-node with single indirect block b, i-node with triple indirect block c, FAT 32 d, FAT 16

B

Question #38 (1 point) Which class of I/O devices that disks and tapes belong to? Stream devices Block devices Character devices None of the other choices

B

Question #46 (1 point) Which part of a disk is used to boot the computer? Free block MBR Root block Super block

B

Question #47 (1 point) Which solution is used to solve the "missing block" problem for file system consistency? a, The file system checker rebuilds the free list b, The file system checker adds the missing blocks to the free list c, The file system checker allocate the free block, then copy the duplicate block in used to there d, None of the other choices

B

Question #48 (1 point) The File Manager writes the volume name and other descriptive information on an easy-to-access place on each unit: ____ of the magnetic disk The outermost part The innermost part Immediately following the master file directory Stored at the beginning of the volume

B

Question #6 (1 point) Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the average turnaround time for SJF (Shortest job first) scheduling. Ignore process switching overhead. A.14 minutes B.8 minutes C.6 minutes D.18.8 minutes

B

What is the purpose of process synchronization? A. Let different users run different processes independently B. Avoid race condition C. Avoid deadlock D. None of the other choices

B

Which of a system call is to allow the system free up internal table space? A. OPEN B. CLOSE C. SEEK D. DELETE

B

Which of the following conditions that causes the processes to be terminated, when the processes have a program bug? A. Normal exit (voluntary ) B. Error exit (voluntary) C. Fatal error (involuntary) D. Killed by another process (involuntary)

B

Which of the following is not special file? A. Character special file B. Stream special file C. Block special file D. None of the other choices

B

Which of the following is specified to indicate the directory where the file is located? A. Extension B. Path name C. Root directory D. Sub-directory

B

Which of the following process state transitions is correct, when the operating system discovers that process cannot continue right now because of is not enough resource? A. Running -> Blocked (waiting) B. Running -> ready C. Blocked (waiting) -> ready D. Ready -> running

B

____ are special files with listings of filenames and their attributes. A. Databases B. Directories C. Programs D. Data files

B

A computer has four page frames. The time of loading, time of last access, and the R and M bits for each page are as shown below (the times are in clock ticks): Page Loaded Last ref. R M -------------------------------------------------------------------------------------- 0 226 280 0 0 1 160 265 0 1 2 110 270 1 0 3 120 285 1 1 Which page will FIFO replace? A. 0 B. 1 C. 2 D. 3

C

File is generally defined to be: A. A basic element of data B. A collection of related fields C. A collection of similar records D. None of the other choices

C

How many percent of the CPU time is wasted, when a computer system has enough room to hold two programs and these programs are idle waiting for I/O 10% of the time? A. 90% B. 99% C. 1% D. None of the other choices

C

How many ways is Thread implemented? A. 1 B. 2 C. 3 D. None of the other choices

C

In a single processor system, mutual exclusion can be guaranteed by: A. Overlapping processes B. Interleaving processes C. Disabling interrupts D. All of the other choices

C

OS Windows use system call_____, while OS Unix use system call______ to terminate processes normally A. exit; ExitProcess B. ExitProcess; exit C. ExitProcess; terminate D. terminate; ExitProcess

C

Question #13 (1 point) Which of the following statements is not correct about "device independence"? Files and devices are accessed in the same way, independent of their physical nature A system has to maintain only one set of system calls for both writing on a file and writing on the console Device independence requires all programmers to deal with different devices directly Device independent interfaces should be given to programmers

C

Question #14 (1 point) In separating I/O and memory space system, the set of I/O ports form the I/O port space. This mechanism allows: a, Programs in user space can easily access to I/O devices b, Only programs in kernel can access to I/O devices c, Both programs in user space and kernel can access to I/O devices d, None of the other choices

C

Question #19 (1 point) Which of the following statements is incorrect? The term data rate refers to the speed with which data moves to and from the individual I/O device In the interrupt-driven I/O technique, the processor issues an I/O request, continues with other work and eventually receives notification that the request was fulfilled A hard drive is an example of a I/O character device None of the other choices

C

Question #21 (1 point) Some systems increase the priority of jobs that have been in the system for an unusually long time to expedite their exit, which is known as ____.? a,Lagging b,Bumping c,Aging d,Accelerated priority

C

Question #24 (1 point) The term _____ characterizes a system configuration that includes an I/O module that is a separate processor with a specialized instruction set. a, I/O device b, Programmed I/O c, DMA d, None of the other choices

C

Question #25 (1 point) Disk can be divided up into one or more partitions. The first block of every partition is called: Free block MBR Boot block Super block

C

Question #29 (1 point) Which one cannot be able to solve the race condition? a, TSL b, Shared memory c, Semaphore d, Monitor

C

Question #31 (1 point) Strategy used for dumping a disk to tapes is: Physical dump Logical dump Both physical dump and logical dump None of the other choices Both physical dump and logical dump None of the other choices

C

Question #35 (1 point) Assume that four jobs A-D require the CPU cycles listed below. Using the Shortest Job First algorithm, the ____ job is run first. Arrival time: 4 1 0 2 Job: A B C D CPU cycle: 5 2 6 4 A B C D

C

Question #35 (1 point) Which of the following information contain in the entry of the partition tables? a, Starting and ending address of each partition b, Marking a partition as active c, Both starting and ending address of each partition and marking a partition as active d, None of the other choices

C

Question #37 (1 point) Which of the following allocation methods the i-nodes use? Contiguous allocation Linked allocation Indexed allocation Linked allocation using FAT

C

Question #39 (1 point) Which is the maximum number of partition that most disks can be divided up? 2 3 4 5

C

Question #42 (1 point) Which of the following is correct about symbolic links? a, Symbolic links need not space to store the path name b, Symbolic links can only point to files on the same machines c, Symbolic links can point to files in the network d, None of the other choices

C

Question #49 (1 point) Which classes of I/O devices that keyboard belong to? Stream devices Block devices Character devices None of the other choices

C

Question #5 (1 point) In general, which is the best technique for I/O Data transfer? a, Programmed I/O b, Interrupt-Driven I/O c, Direct Memory Access d, None of the other choices

C

Question #8 (1 point) Which of the following is a preemptive scheduling algorithm A.FCFS B.Shortest Job First C.Round Robin D.None of the other choices

C

Sometimes it happens that a thread wants to give another thread a chance to run. It can establish this goal by calling______ A. thread_create B. thread_exit C. thread_wait D. thread_yield

C

The absolute pathname of a file in Linux is with respect to the A. Home directory B. Login directory C. Root directory on the system D. All of the other choices

C

What is the "sequential processes" concept? A. There are both many CPU and many PC B. All process is executed in concurrency C. No concurrency inside a process; everything happens sequentially D. None of the other choices

C

Which conditions of mutual exclusion does the Lock Variables (Software proposal) violate? A. No two processes simultaneously in critical region B. No assumptions made about speeds or numbers of CPUs C. No process running outside its critical region may block another process D. No process must wait forever to enter its critical region

C

Which is special file? A. character special file B. block special file C. Both character special file and block special file D. None of the other choices

C

Which kind of tables is used in the segmentation? A. Global Descriptor Table (GDT) B. Local Descriptor Table (LDT ) C. Both Global Descriptor Table (GDT) and Local Descriptor Table (LDT ) D. None of the other choices

C

Which of a system call is to allow the system announce that the file is coming and set some of the attributes? A. OPEN B. CLOSE C. CREATE D. RENAME

C

Which of the following conditions that causes the processes to be terminated, when the processes executes a system call tell the OS to finish some other process? A. Normal exit (voluntary ) B. Error exit (voluntary) C. Fatal error (involuntary) D. Killed by another process (involuntary)

C

Which of the following is not file structure? A. Byte sequence B. Record sequence C. Ring D. Tree

C

____ is a specialized WRITE command for existing data files that allows for appending records or for rewriting selected records in their original place in the file. A. APPEND B. UPDATE C. REWRITE D. MODIFY

C

In some thread systems, a thread want be blocked until an other thread has exited. It can establish this goal by calling______ A. thread_create B. thread_exit C. thread_wait D. thread_yield

D

Question #1 (1 point) Programmed I/O should be acceptable for which of the following systems? Interactive systems Multiprogramming systems Embedded systems None of the other choices

D

Question #11 (1 point) Which is the right order between the 4 I/O software layers? User-level I/O software, Device drivers, Interrupt handlers, Device-independent OS software User-level I/O software, Interrupt handlers, Device drivers, Device-independent OS software Device-independent OS software, user-level I/O software, Device drivers, Interrupt handlers User-level I/O software, Device-independent OS software, Device drivers, Interrupt handlers

D

Question #12 (1 point) .What is Software proposal in the solution of Mutual exclusion with Busy waiting? A.Message passing B.Monitors C.Peterson's Solution D.All of the other choices

D

Question #13 (1 point) Which of the following is appropriate to release page table and pages? A.Process creation B.Process execution C.Page fault time D.Process termination time

D

Question #18 (1 point) Which of the following statement is not true about separating I/O and memory space? Device drivers must be written using assembly language Programs must use 2 instructions to test whether the device is ready There is special protection mechanism to keep user processes from performing I/O Caching a device control register would be disastrous

D

Question #2 (1 point) Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. . Determine the average waiting time for FCFS scheduling. Ignore process switching overhead. A.17 minutes B.18 minutes C.18.8 minutes D.12,8 minutes

D

Question #2 (1 point) Which of the following statements is not correct about the device controller of I/O devices? a, Is electronic component of device b, Is also called adapter c, Can handle two, four, or even eight identical devices d, Is software component of device

D

Question #22 (1 point) DMA operations require the following information from the processor a, Address of I/O device b, Starting memory location to read from and write to c, Number of words to be read or written d, All of the other choices

D

Question #22 (1 point) Which of the following is true about Atomic action on semaphores? a,Checking the value b,Changing the value c,Possibly going to sleep d,All of the other choices

D

Question #23 (1 point) Which are allocation methods of disk blocks for files? Contiguous allocation Linked allocation Indexed allocation All of the other choices

D

Question #26 (1 point) Which of the following statements about the task of device controller of I/O devices is correct? Convert serial bit stream to block of bytes Perform error correction as necessary Make available to main memory All of the other choices

D

Question #27 (1 point) The disk block in a partition that includes a magic number, the number of blocks in the file system and other key administrative information is called: a, Free block b, MBR c, Boot block d, Superblock

D

Question #28 (1 point) The main classes of I/O devices are: Stream devices Block devices Character devices Block devices and Character devices

D

Question #34 (1 point) Which is not attribute of MS-DOS file? Read-Only Archived Hidden, System Lock

D

Question #4 (1 point) Which of the following statements about semaphores is true? A.P and V (Down and Up) operations should be indivisible operations B.If several processes attempt a P(S) operation simultaneously, only one process should be allowed to proceed. C.A semaphore implementation should guarantee that processes do not suffer indefinite postponement. D.All of the other choices

D

Question #40 (1 point) An example of a I/O character devices is CD ROM Disks Modem All of the other choices

D

Question #43 (1 point) Which is the maximum partition size, if the FAT type is FAT-16 and the block size is 2 KB? 8 MB 128 MB 256 MB 512 MB

D

Question #44 (1 point) Which of a system call is to allow the file to appear in more than one directory? OPEN SEEK CREATE LINK

D

Question #5(1 point). _____ is the act of allowing only one process to have access to a dedicated resource A.No preemption B.Circular wait C.Resource holding D.Mutual exclusion

D

Question #6 (1 point) An example of the key differences that can exist across (and even in) types of I/O devices is: Data rate Data representation Error conditions All of the other choices

D

Question #7 (1 point) Which approach is used in order to CPU communicate with the control registers of the I/O device? a, Separating I/O and memory space b, Memory-mapped I/O c, Hybrid: separating I/O and memory space and memory-mapped I/O d, All of the other choices

D

The following requirement must be met by any facility or capability that is to provide support for mutual exclusion: A. Only one process at a time can be allowed into a critical section B. A process remains in its critical region for a finite time only C. No assumption can be made about relative process speeds D. All of the other choices

D

What is Software proposal in the solution of Mutual exclusion with Busy waiting? A. Lock Variables B. Strict Alternation C. Peterson's Solution D. All of the other choices

D

Where should be put the page replacement algorithm In Mach model of Page fault handling with an external pager? A. In the low-level MMU handler B. In the page fault handler that is part of the kernel C. In the external pager running in user space D. All of the other choices

D

Which conditions of mutual exclusion does the Strict Alternation (Software proposal ) violate A. No two processes simultaneously in critical region B. No assumptions made about speeds or numbers of CPUs C. No process running outside its critical region may block another process D. No process must wait forever to enter its critical region

D

Which of a system call is to allow the system fetch the attributes and list of disk addresses into main memory for rapid access on later call? A. OPEN B. CLOSE C. SEEK D. RENAME

D

Which of the following cannot be shared among different threads of a process? A. Process code B. File handles C. Process data D. Stack

D

Which of the following is appropriate to release page table and pages? A. Process creation B. Process execution C. Page fault time D. Process termination time

D

Which of the following process state transitions is correct, when the external event for which a process was waiting happens? A. Running -> Blocked (waiting) B. Running -> ready C. Blocked (waiting) -> ready D. Ready -> running

D

Which of the following process state transitions is correct, when the scheduler picks a process from the ready queue to run? A. Running -> Blocked (waiting) B. Running -> ready C. Blocked (waiting) -> ready D. Ready -> running

D

Which of the following statements about segmentation is false? A. There are several linear address spaces B. The total address space can be more than the size of physical memory C. Sharing of procedures between different users can be facilitated D. None of the other choices

D

Which statement about disabling interrupts to resolve race conditions is wrong? A. In theory, a program can disable interrupts when it enters a critical section, and re-enable interrupts when finished with a critical section, to eliminate race conditions. B. Disabling/enabling interrupts may negatively affect the I/O system. C. Programs with infinite loops in their critical sections are a significant problem with the interrupt-based approach. D. User-mode programs are the best place to invoke disableInterrupt().

D

Which statement about disadvantage of Disabling interrupts, (the hardware solution to the critical region problem) is correct? A. If process is locked in Critical Section: System Halt B. Permit process to use command privileges: Danger! C. Don't ensure Mutual Exclusion for the system with N CPUs D. All of the other choices

D

____ is the act of allowing only one process to have access to a dedicated resource A. No preemption B. Circular wait C. Resource holding D. Mutual exclusion

D

A CPU may have separate fetch, decode and execute units, so that can carry out three steps of the three instructions in the same time is called: a,Pipeline b,Superscalar c,Multicore d,None of the other choices

a

A computer with a 32-bit address uses a two-level page table. Virtual addresses are split into a 9-bit top-level page table field, an 11-bit second-level page table field, and an offset. How many pages are there in the address space? 2^20 pages 2^21 pages 2^22 pages 2^23 pages

a

A system with 32 bit virtual address. If the page size is 16 KB and each table entry occupies 4 bytes, what is the size of the page table? 1 MB 2 MB 4 MB 8 MB

a

Assume that process A-D make up the set of runnable processes on memory as B1 B2 B3 A1 A2 A5 A7 D3 D4 D6 C1 C6 C5. Suppose D gets a page fault. Which page is replaced using the local policy? Assume that the replaced page is always a last page. D6 B3 C5 None of the others

a

Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Their (externally determined) priorities are 3, 5, 2, 1, and 4, respectively, with 5 being the highest priority. Determine the average waiting time for Priority scheduling. Ignore process switching overhead. 10,8 minutes 12,8 minutes 16,8 minutes 54 minutes

a

In "No Memory Abstraction", the static relocation technique is ____ a, When the program is loaded at address n, the constant n was added to every program address b, When the program is compiled, the address of program is added with the constant value where the program will be loaded c, After the program is loaded at address n, the constant n is stored at a particular register. d, None of the other choices

a

Question #18 (1 point) Which method is used to implement files to keep each file as a linked list of disk blocks? a, Linked List Allocation b, Contiguous Allocation c, File Allocation Table i-node

a

Question #20 (1 point) Which is the maximum partition size, if FAT type is FAT-12 and the block size is 2 KB? 8 MB 128 MB 256 MB 512 MB

a

Question #26 (1 point) Which of the following statements is true about hardware solution to the critical region problem? a, Disable Interrupts b, Monitors c, Semaphore d, None of the other choices

a

Question #3 (1 point) Which statement about DMA is incorrect? a, The controller does not need to wait for the CPU to transfer data to/from memory b, The CPU can start a DMA block transfer, and in the mean time do other work c, The CPU needs not to be concerned with the time it takes to transfer data d, It is always true that DMA is less expensive than CPU-mediate data transfers

a

Question #41 (1 point) Which is space efficiency, if 4KB-file using file system with 8KB-block? 50% 75% 25% 100%

a

Question #45 (1 point) An example of a I/O block devices is CD ROM Printer Modem All of the other choices

a

Question #5 (1 point) Which of a system call is to allow the system to specify from where to take the data in file? OPEN SEEK CREATE LINK

a

Question #7 (1 point) Which of the following is not correct about the main classes of I/O devices? a, Stream devices b, Block devices c, Character devices d, Block devices and Character devices

a

The page table for each process maintains: The page frame location for each page of the process The page location for each frame of the process The physical memory location of the process None of the other choices

a

The second-chance page-replacement algorithm a, Moves pages found at the head of a FIFO queue with the referenced bit turned on back to the tail of the queue to avoid replacing them b, Searches through a circular list of pages and replaces the first page it encounters that has the referenced bit turned off c, Relies on a modified bit to determine which page to replace d, None of the other choices

a

The two basic types of processor registers are: a,General and special registers b,Control and Status registers c,User-visible and user-invisible registers d,None of the other choices

a

There are ____ entries per page in the Page table. 1 2 3 4

a

Which is not an example of a resource that is commonly space-multiplexed? a, CPU b, Video RAM c, Hard drive d, Main memory

a

Which of the events that causes the processes to be created, when an operation system is booted? A. System initialization B. Execution of a process creation system call C. User request to create a new process D. Initiation of a batch job

a

Which of the following actions generates an external interrupt? a,An input/output operation is completed. b,A page that does not exist in the main memory is accessed by the virtual storage management. c,A system call instruction is executed. d,Division by zero occurs.

a

Which of the following information bits in the entry of page table is used to indicate Page Fault? Present/absent bit Status bit Referenced bit Modified bit

a

Which of the following instructions should be allowed only in kernel mode? a,Disable all interrupts b,Read the time-of-day clock c,AND of two numbers d,ADD of two numbers

a

Which of the following is appropriate to determine program size and create page table? Process creation Process execution Page fault time Process termination time

a

Which of the following is not a step in the boot process? [A] The antivirus program checks all files for viruses. [B] Configuration and customization settings are checked [C] The operating system is loaded into RAM. [D] The BIOS is activated by powering on the CPU.

a

Which of the following statements about Electrically Erasable PROM(EEPROM) is correct? a, Can be erase and rewritten b, Volatile c, Unprogrammable d, None of the other choice

a

Which of the following statements is incorrect about Translation Look-aside Buffer (TLB)? a, A TLB is sometimes known as an associative memory b, Each entry of a TLB contains the information about one page, including the virtual page number and the corresponding page frame c, A TLB miss implies a disk operation will follow d, None of the other choices

a

Which of these statements about the Inverted Page Table are true? a, An entry contains the pair (process, virtual page) mapped into the corresponding page frame b, An entry contains the pair (process, offset) mapped into the corresponding page frame b, An entry contains the pair (segment, virtual page) mapped into the corresponding page frame c, An entry contains the pair (segment, offset) mapped into the corresponding page frame

a

Which strategy is a simplest design for speeding up Paging? Page table is loaded into registers Page table is loaded into main memory Page table is loaded into disk Page table is loaded into TLB

a

Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the average waiting time for SJF (Shortest job first) scheduling. Ignore process switching overhead. 14 minutes 8 minutes 6 minutes 18.8 minutes

b

In a system employing a paging scheme for memory management, wasted space is due to: External fragmentation Internal fragmentation Pages and frames of different specified sizes None of the other choices

b

In terms of speed the best method of Dynamic Storage-Allocation is: Next fit First fit Best fit Worst fit

b

LRU replaces the page that has spent the a, longest time in memory b, longest time in memory without being referenced c, shortest time in memory d, shortest time in memory without being referenced

b

List memory location, that contains the executable program, the program, the program's data, and its stack is called: a, set of resources b, address space c, address memory d, All of the other choices

b

QN=1 (6836) A CPU may have multiple execution units, so that can carry out multiple instructions in the same time is called: a. Pipeline b. Superscalar c. Multicore d. None of the other choices

b

QN=4 (6860) Which of the following statements about Random Access memory (RAM) is correct? a. Is typically faster than cache memory b. Is volatile c. Can only be read sequentially d. Stores all the files on the computer

b

QN=5 (6863) Information that must be saved prior to the processor transferring control to the interrupt handler routine includes: a. PSW b. PSW and PC c. PSW and Contents of processor registers d. None of the other choices

b

QN=8 (2293) A Control/Status register that contains the address of the next instruction to be fetched is called the: a. Instruction Register (IR) b. Program Counter (PC) c. Program Status Word (PSW) d. All of the above

b

QN=9 (2291) The general role of an operating system is to: a. Act as an interface between various computers b. Provide a set of services to system users c. Manage files for application programs d. None of the above

b

Question #12 (1 point) Which of the following is true about the block size in disk space management a, The larger the block size is the lower the data rate is b, The larger the block size is the worse the disk space utilization is c, The larger the block size is lesser the disk space is d, None of the other choices

b

Question #18 (1 point) What is the purpose of process synchronization? Let different users run different processes independently Avoid race condition Avoid deadlock None of the other choices

b

Question #19 (1 point) Which of the following is true about the data rate for disk management? a, The larger the block size is the faster the data rate is b, The larger the block size is the lower the data rate is c, The larger the block size is lesser the disk space is d, None of the other choices

b

Question #22 (1 point) Which classes of I/O devices that Clock belong to? Stream devices Block devices Character devices None of the other choices

b

Question #32 (1 point) The disk blocks in a partition that contains the top of the file system tree is called: a, Free space management blocks b, Root directory c, Boot block d, Superblock

b

The page size that is too small will generate ____ a, Excessive internal fragmentation b, Very long Page tables c, More difficult to calculate actual position d, Excessive external fragmentation

b

What is interrupt vector? a,A signal an I/O device sends to CPU b,The addresses of interrupt handlers c.Part of memory which contains the addresses of interrupt handlers d,None of the other choices

b

What is not the technique of implementation for Virtual Memory? a, Segmentation b, Partition c, Paging d, All of the other choices

b

When a virtual memory system manages memory in fixed length units, which of the following terms correctly represents its unit? Frame Page Block Segment

b

Where is the position of the operating system in computer system: a,Above the hardware and under the user interface program b,Between the user interface program and the application Program c,In user space d,None of the other choices

b

Which of following is true about main memory in the memory hierarchy? Small amount of fast expensive memory Some medium-speed medium price Gigabytes of slow cheap memory None of the other choices

b

Which of special register in the CPU points to the current stack in the memory? a, IR b, PC c, PSW d, SP

b

Which of the events that causes the processes to be created, when a running process creates one or more new process to help it to do its job? A. System initialization B. Execution of a process creation system call C. User request to create a new process D. Initiation of a batch job

b

Which of these statements about the algorithm "Next fit" is true? a, Memory Manager scans along the list of segments until it finds a hole that is big enough. b, Memory Manager starting searching the list of segments from the place where it left off last time. c, Memory Manager searches the entire list of segments from beginning to end and take smallest hole that is adequate. d, None of the other choices

b

Which solutions are used to solve the shared libraries? a, Relocation on the fly and position-independent code b, Position-independent code c, Static reallocation and position-independent code d, None of the other choices

b

With paging, when is the internal fragmentation possible? a, Page does not fit the frame b, The last page of the job is less than the maximum page size c, The virtual memory assigned to the program is less than the physical memory assigned to it d, Such thing cannot happen

b

Working set model is used for: a, Finding the minimum number of frames necessary for a job so that jobs can be run without "thrashing" b, Finding the average number of frames a job will need to run smoothly c, Determining whether page replacement is needed d, All of the other choices

b

____ gives users the appearance that their programs are being completely loaded in main memory during their entire processing time. Segmenting Virtual memory Shared memory Multithreading

b

A CPU may have two or more complete processors, so that can carry out multiple threads in the same time is called: a,Pipeline b,Superscalar c,Multicore d,None of the other choices

c

An operating system a, Manages hardware resources in a computer system b, Manages software resources in a computer system c, Deals with complex hardware resources and provides the user a virtual/ extended machine that is much easier to deal with than the physical machine d, All of the other choice.

c

As one proceeds down the memory hierarchy (from inboard memory to offline storage), the following conditions apply: a,Decreasing cost per bit b,Increasing capacity c,Increasing access time d,All of the other choices

c

Assume the Memory Manager receives a request for a block of 200. When the first-fit algorithm is used, ____ is the beginning address of the block granted by the Memory Manager. Beginning Address Memory Block Size 4075 105 5225 5 6785 600 7560 20 7600 205 10250 4050 a, 7600 b, 10250 c, 6785 d, 4075

c

Consider a swapping system in which the memory consists of the following hole sizes: 10K, 4K, 20K, 15K, 9K. Assume best fit algorithm is used. Which holes are taken for successive segment requests of 8K, 12K, 10K? 20K, 15K, 10K 10K, 15K, 20K 9K, 15K, 10K 10K, 20K, 15K

c

Examples of general purpose stored program computers include the following except: a, Personal computer b, Network service c, Workstation d, MP3 player

c

In terms of storage utilization the best method of Dynamic Storage Allocation is: a, Next fit b, First fit c, Best fit d, Worst fit

c

Page replacement algorithms determine a,When the system should update page table entries b,How many pages should be added to main memory c,Which pages should be brought into memory because a process is likely to reference them soon d,Which page to remove to provide space for an incoming page

c

QN=1 (6840) Which of special register contains the Mode Bit (user or kernel)? a. Instruction Register (IR) b. Program Counter (PC) c. Program Status Word (PSW) d. None of the other choices

c

QN=2 (6843) The four main structural elements of a computer system are: a. Processor, Registers, I/O Modules, Main Memory b. Processor, Registers, Main Memory, System Bus c. Processor, Main Memory, I/O Modules, System Bus d. None of the other choices

c

QN=4 (6858) As one proceeds down the memory hierarchy(phân cấp bộ nhớ) (from inboard memory to offline storage), which of the following conditions is correct? a. Increasing cost per bit b. Decreasing capacity c. Increasing access time d. None of the other choices

c

Question #10 (1 point) In the memory-mapped I/O system, in order that CPU communicates with the control registers in the devices, the control register is assigned : a, Index b, I/O address c, Unique memory address d, None of the other choices

c

Question #16 (1 point) One of the primary disadvantages of contiguous storage is that ____. a, It is hard to implement and manage b, It is difficult to find information in files c, File can't be expanded unless there is empty space available immediately following it d, It is an inefficient use of space

c

Question #17 (1 point) Which class of I/O devices that Scanner belongs to? a, Stream devices b, Block devices c, Character devices d, None of the other choices

c

Question #19 (1 point) Which of the following conditions of semaphore variable "s" implies a busy critical region? a, s > 0 b, s < 0 c, s = 0 d, None of the other choices

c

Question #2 (1 point) Which mechanism is described as "the device controller sneaks in and steals an occasional bus cycle from the CPU once in a while, delaying it slightly"? a, Interrupt stealing b, Cycle sneaking c, Cycle stealing d, All of the others

c

Question #21 (1 point) Which ways are used to keep track of free block in disk space management? A linked list method A bitmap method Both linked list method and bitmap method None of the other choices

c

Question #23 (1 point) Which of the following statement is correct about a disadvantage of memory-mapped I/O? Since the control registers of devices are mapped into the memory space, device drivers can be written in C Programs can use 1 instructions to test whether the device is ready Caching a device control register would be disastrous None of the other choices.

c

Question #3 (1 point) Which of the following is not correct about hard links? a, Hard links can point to files in the network b, Hard links do not require extra disk space c, Hard links can only point to files on the same machines d, Hard links require to increase the link count in the i-node for each linking

c

Question #4 (1 point) What is incorrect about contiguous allocation of files? a, It is simple to implement b, It leads to excellent read performance c, It does not cause disk fragmentation d, It is widely used on CD-ROMs

c

Question #50 (1 point) Which of the following is not a well-known technique for organizing the physical storage blocks for a file? a, Contiguous block allocation b, Linked list block allocation c, Sparse block allocation d, Indexed block allocation

c

Question #8 (1 point) Which of the following statements is not correct about DMA? a, DMA controller has access to the system bus independent of the CPU b, DMA helps reduce the number of interrupts (in comparison with interrupt-driven I/O) c, DMA controller is usually faster than CPU d, The operating system can only use DMA if the hardware has a DMA controller

c

Suppose a virtual address space of 2^24 words and the page size is 2^12 words. If the virtual address is 123456 in Hexadecimal, what would be the page number in Hexadecimal? 123 1234 12345 123456

c

The ____ policy is based on the theory that the best page to remove is the one that has been in memory the longest NRU LRU FIFO LIFO

c

The actual location in main memory is called a(n): a, Relative address b, Logical address c, Absolute address d, None of the other choices

c

The language of the CPU is known as its [A] Register set [B] Control unit set [C] Instruction set [D] None ofthe other choices

c

The methods determine where page is on the disk when it is paged out is a, Paging to a static swap area b, Backing up pages dynamically c, Both Paging to a static swap area and Backing up pages dynamically d, None of the other choices

c

The modified/dirty bit is used for the purpose of: a, Implementing FIFO page replacement algorithm b, Dynamic allocation of memory used by one process to another c, Reduce the average time required to service page faults d, None of the other choices

c

The task of subdividing memory between the OS and processes is performed automatically by the OS and is called: a, Protection b, Relocation c, Memory Management d, All of the other choices

c

To specify an address in this segmented memory, the _____ form is used [A] <physical address, offset> [B] <process, offset> [C] <segment-number, offset> [D] <virtual address, offset>

c

What is not a main function of an operating system? a,Provide the users with an extended (virtual) machine b,Manage the I/O devices c,Provide user interfaces d,Support virtual memory

c

When there is an excessive amount of page swapping between main memory and secondary storage, the operation becomes inefficient, which is called ____. excessive demand paging hot swapping thrashing Over swapping

c

Which is not true about the method of backing store: "Paging to a static swap area"? a, The swap area on the disk is as large as the process virtual address space b, Calculating the address in swap area requires knowing only where the process' paging area begins c, Requires a disk map in memory d, A page that is in memory always have shadow copy on disk

c

Which of following is true about disk storage in the memory hierarchy? Small amount of fast expensive memory Some medium-speed medium price Gigabytes of slow cheap memory None of the other choices

c

Which of the following information bits in the entry of page table is used to indicate what kinds of access are permitted? Present/absent bit Caching disabled Protection bit Modified bit

c

Which of the following is a method to keep track of memory usages? a, Memory Management with Bit Maps b, Memory Management with Linked Lists c, Both Memory Management with Bit Maps and Memory Management with Linked Lists d, None of the other choices

c

Which of the following is not a operating mode of CPU a, User mode b, Kernel mode c, Management mode d, None of the other choices

c

Which of the following statements is incorrect about the CMOS? a,Is volatile b,Interrupt c,To contain BIOS d,To hold the configuration parameters

c

Which of these statements about the algorithm "Best fit" is true? a, Memory Manager scans along the list of segments until it finds a hole that is big enough. b, Memory Manager starting searching the list of segments from the place where it left off last time. c, Memory Manager searches the entire list of segments from beginning to end and take smallest hole that is adequate. d, None of the other choices

c

A computer has 2GB RAM of which the operating system occupies 1GB. The processes are all 450 MB and have the same characteristics. How many percent of the CPU time is wasted, when these programs are idle waiting for I/O 20% of the time? A. 90% B. 96% C. 4% D. None of the other choices

d

A page fault means that we referenced a page That was outside the memory boundaries With an incorrect I/O request That was not in secondary storage That was not in main memory

d

Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. . Determine the average waiting time for FCFS scheduling. Ignore process switching overhead. 17 minutes 18 minutes 18.8 minutes 12,8 minutes

d

If there are 64 pages and the page size is 2048 words, what is the length of logical address? 14 bits 15 bits 16 bits 17 bits

d

One of the most important innovations of demand paging was that it made ____ feasible Memory demand Virtual demand Virtual paging Virtual memory.

d

QN=3 (6855) Booting a general purpose computer involves the following steps except a, Execution of a Rom-base POST sequence b, Load OS c, Load one or more process d, Loading the command interpreter

d

Question #11 (1 point) A directory in UNIX/Linux consists of: I-node number and file name File name, file size, location of the file on disk File name, file size, location of the file on disk, date created, owner ID None of the other choices

d

Question #13 (1 point) Which of the following is not correct about hard links and symbolic links? a, Symbolic links need space to store the path name and considerable number of extra disk accesses b, Hard links do not require extra disk space c, Symbolic links can point to files in the network d, Hard links can point to files on other machines

d

Question #14 (1 point) Increasing file system performance is implemented by _____ Buffer cache Block Read Ahead Defragmenting Disks All of the other choices

d

Question #15 (1 point) Which of the following allocation methods, Operating system MS-DOS is implemented? Contiguous allocation Linked allocation Indexed allocation Linked allocation using FAT

d

Question #28 (1 point) Which of the following environments preemption is essential? Batch Interactive Real time None of the other choices

d

Question #6 (1 point) Which of the following statements about device drivers is correct? a, Device drivers lie on top of I/O software layer architecture b, Device drivers lie on bottom of I/O software layer architecture c, Device drivers layer lies right above the interrupt handlers layer and below the device-independent OS software layer d, None of the other choices

d

Question #8 (1 point) A table in main memory storing linked list of allocation of disk blocks is called: a, Disk allocation table b, Linked list table c, File list table d, File allocation table

d

Question #9 (1 point) The Joliet Extensions provide ________ a, Long file name supported Unicode character b, Directory nesting deeper than 8 levels c, Directory names with extensions d, All of the other choices

d

The ways that input/output can be done is? a, Busy waiting b, Interrupt c, DMA d. All of the above

d

Which is not true about "Backing up pages dynamically"? a, Pages do not have fixed swap area on the disk b, Requires a disk map in memory c, When a page is swapped out, an empty disk page is chosen on the fly and disk map is updated accordingly d, Needs less main memory than the method "Paging to a static swap area"

d

Which of following statements about the memory hierarchy is false? Small amount of fast expensive memory - cache Some medium-speed medium price main memory Gigabytes of slow cheap disk storage None of the other choices

d

Which of the events that causes the processes to be created, when the operation system creates a new process and runs the next job from the input queue? A. System initialization B. Execution of a process creation system call C. User request to create a new process D. Initiation of a batch job

d

Which of the following process state transitions is illegal? A. Running -> Blocked (waiting) B. Running -> ready C. Blocked (waiting) -> ready D. Ready -> Blocked (waiting)

d

Which of the following statements about the CPU handling interrupts is incorrect? a, The process ceases to execute the current sequence of instructions b, The hardware saves the old PC location c, The CPU branches to a new instruction sequence d, None of the other choice

d

Which of these statements about the algorithm "Worst fit" is true? a, Memory Manager scans along the list of segments until it finds a hole that is big enough. b, Memory Manager starting searching the list of segments from the place where it left off last time. c, Memory Manager searches the entire list of segments from beginning to end and take smallest hole that is adequate. d, None of the other choices

d