Part2

B

____________allows a resource to be held by a process as long as it is needed. [A] No preemption condition [B] Hold and wait condition [C] Circular-wait condition [D] Mutual-exclusion condition

D

_________is the act of allowing only one process to have access to a dedicated resource [A] Hold and wait condition [B] No preemption condition [C] Circular-wait condition (Circular wait condition) [D] Mutual-exclusion condition (Mutual exclusion condition)

A

______allows a resource to be held by a process as long as it is needed [A] Hold and wait condition [B] Mutual-exclusion condition [C] No preemption condition [D] Circular-wait condition

B

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] UPDATE [B] REWRITE [C] MODIFY [D] APPEND

B

is when, in modern printing systems, a disk accepts output from several users and acts as a temporary storage area for all output until the printer is ready to accept it [A] Lagging [B] Spooling [C] Spoofing [D] Buffering

C

what is Sofware 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

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 is CPU utilization when these programs are idle waiting for I/O 20% of the time? 4% 90% [C] None of the other choices [D] 96%

D

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

B

A operation concerning Stable Storage is: [A] Stable Reads [B] All of the other choices [C] Crash recovery [D] Stable writes

A

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

B

All deadlocks involve conflicting needs for resources by [A] None of the other choices [B] Two or more processes [C] One or more processes [D] Three or more processes

D

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

D

An example of preemptable resources is [A] DVD device [B] None of the other choices [C] CD-ROM device [D] Memory

D

Assuming that it takes 10 nsec to copy a byte, how much time does it take to completely rewrite the screen of a 1200 x 800 pixel graphics with 24- bit color? [A] 288 msec [B] 288 micro-sec [C] 28.8 micro-sec [D] 28.8 msec

C

Assuming that it takes 10 nsec to copy a byte, how much time, does it take to completely rewrite the screen of a 200 character x 20 line text mode memory-mapped screen? [A] 10 micro-sec [B] 30 micro-sec c 40 micro-sec [D] 20 micro-sec

B

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

A

Device Driver is usually written by: [A] Device's Manufacturer [B] OS's Manufacturer [C] Computer's Manufacturer [D] All of the other choices

D

Disk can be divided up into one or more partitions. The first block of every partition is called: [A] Super block [B] Free block [C] MBR [D] Boot block

B

File Structure can be: [A] Byte sequence [B] All of the other choices [C] Tree [D] Record sequence

D

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

D

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 10% of the time? [A] 90% [B] 99% [C] None of the other choices [D] 1 %

D

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 10% of the time? [A] 90% [B] 99% [C] None of the other choices [D] 1 %

C

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

A

How much cylinder skew is needed for a 5400- RPM (rotate per minute) disk with the track-to-track seek time of 1 msec? The disk has 200 sectors of 512 bytes on each track. [A] 18 sectors [B] 12 sectors [C] 24 sectors [D] 36 sectors (chú ý: 7200 - 24 & 3600-12)

D

If a system is deadlocked, no processes can [A] release resources [B] be awakened [C] run [D] All of the other choices

A

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

A

Imagine that a certain modem can read 7,000 characters per second and that the time to read a character to the modem register is so short it can be ignored. If to run this modem using interrupt- driven I/O and each character read requires an interrupt that takes 10 usee all-in to service. How many percent of the CPU does the interrupt overhead cost? [A] 4% of the CPU [B] 7% of the CPU [C] 96% of the CPU [D] 93% of the CPU

D

In a directed graph used to model deadlock, ______represents deadlock. [A] Dashed arrow [B] Solid arrow [C] Any path [D] Cycle

C

In a directed graph used to model deadlock, resources are represented using [A] Rectangle [B] Circular [C] Squares. [D] Ellipse

D

In a fixed magnetic disk, each circle is called a [A] platter [B] sector [C] block [D] track

B

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

B

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

B

In terms of disk storage efficiency, the method of "Backing up pages dynamically" in comparison with the method of "Paging to a static swap area" is [A] Worse [B] Better [C] Nearly equal [D] Equal

B

In terms of speed the best method of Dynamic Storage-Allocation is: [A] Next fit [B] First fit [C] Worst fit [D] Best fit

D

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

B

One of the most important innovations of demand paging was that it made feasible [A] Virtual paging [B] Virtual memory. [C] Memory demand [D] Virtual demand

D

Rearrange the layers in I/O software starting at the bottom 1. User-level I/O software 2. Device drivers 3. Interrupt handlers 4. Hardware 5. Device-independent OS software [A] 12345 [B] 54321 [C] 15234 [D] 43251

B

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] None of the other choices [B] Binary semaphores [C] Integer semaphores [D] Counter semaphores

C

The __________ policy is based on the theory that the best page to remove is the one that has been in The memory the longest [A] FIFO [B] LIFO [C] LRU [D] NRU

A

The aspect of disk performance that represents the time it takes to position the head a the desired track is known as [A] Rotational delay [B] Access time [C] Seek time [D] None 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

C

The four main structural elements of a computer system are: [A] None of the other choices [B] Processor, Registers, I/O Modules, Main Memory [C] Processor, Main Memory, I/O Modules, System Bus [D] Processor, Registers, Main Memory, System Bus

C

The permanent blocking of a set of processes that compete for system resources is called [A] Prioritization [B] Starvation [C] Deadlock [D] None of the other choices

C

The permanent blocking of a set of processes that compete for system resources is called [A] Starvation [B] None of the other choices [C] Deadlock [D] Prioritization

C

The term__________a specialized instruction set. [A] None of the other choices [B] I/O device [C] DMA characterizes a system configuration that includes an I/O module that is a separate processor with [D] Programmed I/O

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>

D

What is a "stripping" in RAID? [A] Take away possessions from someone [B] Get undressed [C] All of the other choices [D] Distributing data over multiple drives

D

What is asynchronous transfer in principles of I/O software? [A] The user process makes system call and goes to sleep until other process it wakes up [B] None of the other choices [C] The user program starts system call to transfer and automatically suspended until the data are available in the buffer [D] The CPU starts the transfer and goes off to do something else until the interrupt arrives

B

What is incorrect about contiguous allocation of files? [A] It leads to excellent read performance [B] It does not cause disk fragmentation [C] It is widely used on CD-ROMs [D] It is simple to implement

D

What is the correct approach of the driver of dedicated devices with requesting device that is busy to solve deadlock using Ostrich algorithm? [A] The device driver stops the current jobs and releases the devices [B] The device driver kills those requesting processes [C] All of the other choices [D] The device driver decides blocking and returning an error code

C

What is the correct approach with the "Mutual Exclusion condition" to prevent Deadlock? [A] Take resources away [B] Request all resources initially [C] Spool everything [D] Order resources numerically

C

What is the weakness of the Banker's algorithm? [A] Enabling processes to hold their resources indefinitely [B] Enabling the number of resources to fluctuate [C] Requiring that processes state their maximum needs in advance [D] Allowing the population of processes to vary over time

C

What is true about non-preemptable resources? (non preemptable) [A] Can be taken away from a process with no ill effects [B] None of the other choices [C] Will cause the process to fail if taken away [D] Can share among processes

B

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

A

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

C

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] None of the other choices [B] Halt signal [C] Interrupt signal [D] Handler signal

B

When making CDs for sale, such as music or software CDs, data is recorded on a master disc by means of a high-intensity laser beam, which burns indentations, called pits, and flat areas, called [A] Lakes [B] Lands [C] Valleys [D] Hills

A

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

A

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

A

Which cannot be able to solve the race condition? [A] TSL [B] Shared memory [C] Semaphore [D] Monitor

B

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

B

Which deadlock condition does "Ordering resources numerically" attack? [A] No preemption [B] Circular-wait condition (Circular wait condition) [C] Hold and wait [D] Mutual exclusion

B

Which deadlock condition does "Take resources away" attack? [A] Circular-wait condition (Circular wait condition) B No preemption C Hold and wait [D] Mutual exclusion

B

Which is not a function of device drivers? [A] To manage its power requirements and log events [B] To accept abstract read and write request from device independent software above it and see that they are curried out [C] To receive system call [D] To initialize the device, if needed

A

Which is not a goal of a sheduling algorithm for all systems? [A] Balance [B] Response time [C] Policy enforcement [D] Fairness

B

Which is the correct description of transitions between process states below? (see picture) [A] 1: Process blocks for input; 2: Input becomes available; 3: Scheduler picks another process; 4: Scheduler picks this process [B] 1: Process blocks for input; 2: Input becomes available; 3: Scheduler picks this process; 4: Scheduler picks another process [C] 1: Process blocks for input; 2: Scheduler picks this process; 3: Scheduler picks another process; 4: Input becomes available [D] 1: Process blocks for input; 2: Scheduler picks another process; 3: Scheduler picks this process; 4: Input becomes available

D

Which is the maximum number of partition that most disks can be divided up? [D] 4

D

Which method is used to implement files to keep each file as a linked list of disk blocks? [A] Contiguous Allocation [B] i-node [C] File Allocation Table [D] Linked List Allocation

B

Which method is used to prevent the communication deadlock? [A] All of the other choices [B] Timeouts [C] Handling alarm [D] Acknowledge signal

B

Which of a system call is to allow the file to appear in more than one directory? [A] CREATE [B] LINK [C] OPEN [D] SEEK

A

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

D

Which of a system call is to allow the system free up disk space? [A] OPEN [B] CLOSE [C] SEEK [D] DELETE

C

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

C

Which of the following I/O software do Device drivers do? [A] None of the other choices [B] Checking to see if the user is permitted to use the device [C] Converting binary integers to ASCII for printing [D] Writing commands to the device registers!

A

Which of the following allocation methods, Operating system MS-DOS is implemented? [A] Linked allocation using FAT [B] Indexed allocation [C] Contiguous allocation [D] Linked allocation

B

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

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] Fatal error (involuntary) [B] Error exit (voluntary) [C] Normal exit (voluntary) [D] Killed by another process (involuntary)

A

Which of the following information bits in the entry of page table is false? [A] Present/absent bit [B] Modified bit [C] Protection bit [D] Mode bit

C

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

B

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

C

Which of the following is appropriate to determine program size and create page table? [A] Process termination time [B] Page fault time [C] Process creation [D] Process execution

D

Which of the following is correct about symbolic links? [A] Symbolic links can only point to files on the same machines [B] None of the other choices [C] Symbolic links need not space to store the path name [D] Symbolic links can point to files in the network

A

Which of the following is not a CPU scheduling criterion? [A] Burst time [B] CPU utilization [C] Throughput [D] Response time

D

Which of the following is not a condition necessary for deadlock to exist? [A] Hold and wait condition [B] Mutual-exclusion condition [C] Circular-wait condition [D] Preemption condition

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.

B

Which of the following is not correct about hard links and symbolic links? d [A] Symbolic links need space to store the path name and considerable number of extra disk accesses [B] Hard links can point to files on other machines [C] Hard links do not require extra disk space [D] Symbolic links can point to files in the network

D

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

B

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

A

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

A

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

A

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

B

Which of the following statements about interrupts and trap instructions is incorrect? [A] An interrupt is a hardware-generated change of control flow within the system [B] None of the other choices [C] A trap instruction is a software-generated interrupt [D] An interrupt handler deals with the cause of the interrupt

C

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

B

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

D

Which of the following statements is incorrect about I/O using DMA? [A] None of the other choices [B] DMA helps free up the CPU during the I/O to do other work [C] DMA helps reduce the number of interrupts [D] DMA is software solution to speed up data transfer between I/O device and memory

C

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

C

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

A

Which of these statements about the algorithm "Next fit" is true? [A] Memory Manager starting searching the list of segments from the place where it left off last time. [B] Memory Manager scans along the list of segments until it finds a hole that is big enough. [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