OSG202 version 3

(2311) Which is the correct description of transitions between process states below? (see picture) a. 1: Process blocks for input; 2: Scheduler picks another process; 3: Scheduler picks this process; 4: Input becomes available b. 1: Process blocks for input; 2: Scheduler picks this process; 3: Scheduler picks another process; 4: Input becomes available c. 1: Process blocks for input; 2: Input becomes available; 3: Scheduler picks another process; 4: Scheduler picks this process d. 1: Process blocks for input; 2: Input becomes available; 3: Scheduler picks this process; 4: Scheduler picks another process

a

Assume the following events and actions take place. The following statement is true. Event Action 1 P1 requests and is allocated R1. P1 requests and is allocated R1 2 P2 requests and is allocated R2 3 P3 requests and is allocated R3 4 P1 requests R2. 5 P2 requests R3. 6 P3 requests R1. [A] There is no deadlock [B] Event 5 caused deadlock. [C] Event 4 caused deadlock [D] Event 6 caused deadlock.

a

Consider the case of a home construction company with two application programs, purchasing (P1) and sales (P2), which are active at the same time. They each need to access two files, inventory (F1) and suppliers (F2), to update daily transactions. The following series of events will cause a deadlock. Fill in the missing event in the sequence. 1. Purchasing (P1) accesses the supplier file (F2). 2. Sales (P2) accesses the inventory file (F1). 3. Purchasing (P1) doesn't release the supplier file (F2) but requests the inventory file (F1), but P1 is blocked because F1 is being held by P2. 4. Meanwhile, ____ A) sales (P2) doesn't release the inventory file (F1) but requests the supplier file (F2) B) sales (P2) does release the inventory file (F1) and then requests the supplier file (F2) C) purchasing (P1) does release the supplier file (F2) which is then requested by sales (P2) D) purchasing (P1) exits

a

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

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

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

a

QN=10 (2290) 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 above

a

QN=17 (6980) 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

QN=19 (7547) Which concept is described as "disk sectors are just numbered consecutively starting at 0, without regard to the disk geometry"? a. Logical block addressing b. Physical block addressing c. Virtual block addressing d. None of the other choices

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

a

The system is said to be in an unsafe state if a. The operating system cannot guarantee that all current processes can complete their work b. The system is deadlocked c. A process is indefinitely postponed d. None of the above

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

a

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

a

Which is the fastest bus in the IBM PC computer? [A] ISA (Industry Standard Architecture) [B] USB (Universal Serial BUS) [C] IDE (Integrated Drive Electronic) [D] PCI (Peripheral Component Interconnect)

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

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

a

Which of the following is an Operating System component? [A] Process Management [B] Speed Management [C] Space Management [D] Time Management

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 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 illegal? [A] Ready -> Blocked (waiting) [B] Running -> Blocked (waiting) [C] Blocked (waiting) -> ready [D] Running -> ready

a

With demand paging, jobs are divided into equally sized ____ that initially reside in secondary storage. A) pages B) blocks C) frames D) sets

a

7/ 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

b

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] Multicore [B] Pipeline [C] None of the other choices [D] Superscalar

b

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

b

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

b

A well-known Real-Time operating system is: [A] MS-DOS [B] e-COS [C] Tiny OS [D] Personal Operating System

b

Assume the Memory Manager receives a request for a block of 200. When the best-fit algorithm is used, is the beginning address of the hole granted by the Memory Manager. Beginning Address of Hole Hole Size 4075 105 5225 5 6785 600 7560 20 7600 205 10250 4050 [A] 6785 [B] 7600 [C] 10250

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

Fill in the missing step in the following deadlock situation. Two users from the local board of education are each running a program (P1 and P2), and both programs will eventually need two DVD drives to copy files from one disc to another. Only two DVD-R drives are available and they're allocated on an "as requested" basis. Soon the following sequence transpires: 1. P1 requests drive 1 and gets it. 2. ____ 3. P1 requests drive 2 but is blocked. 4. P2 requests drive 1 but is blocked. A) P1 requests drive 2. B) P2 requests drive 2 and gets it. C) P2 requests drive 1 but is blocked. D) P1 releases drive 1.

b

How many categories can be the I/O devices roughly divided? [A] 3 [B] 2 (block devices and character devices) [C] 4 [D] 1

b

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

b

In the "dining philosophers" problem, a philosopher can pick up a fork when____. A) there is one available B) there are two available C) no other philosopher is eating D) it is his turn, going in numerical order from one philosopher to the next

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

b

QN=1 (2309) Which of the following statements is correct about Shortest Job First a. Avoid Starvation b. Minimize average waiting time c. Both a and b d. None of the above

b

QN=3 (2305) Which of the following process state transitions are legal? a. waiting -> running b. running -> ready c. waiting -> terminated d. ready -> terminated

b

QN=60 (7637) A system has four processes and five allocated resources. The current allocation and maximum needs are as follows: Process Allocated Maximum Available ------------------------------------------------------------------------------------------------------------------ A 10211 11212 00x11 B 20110 22210 C 11011 21311 D 11010 11121 What is the smallest value of x for which this is a safe state? a. 0 b. 1 c. 2 d. 3

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=8 (7455) The File Manager writes the volume name and other descriptive information on an easy-to-access place on each unit: ____ of the magnetic disk a. The outermost part b. The innermost part c. Immediately following the master file directory d. Stored at the beginning of the volume

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

The _________is the essential component ofthe operating system that remains in RAM when your computer is powered on. [A] system file [B] kernel [C] registry

b

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

b

Which deadlock condition does "Take resources away" attack? [A] 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

b

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

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

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

1. The operating system does each of the following except a. Allocates the computer's components to different programs b. Synchronizes individual programs' activities c. Ensures that programs terminate their execution d. Provides the general mechanisms that are needed so that the programs execute in perfect harmony

c

10/ The ways to keep track of memory usages: A/ Memory Management with Bit Maps B/ Memory Management with Linked Lists C/ A vs B D/ None of the above

c

8/ How many levels of Protection the Processor Pentium supports; A. 8 B. 6 C. 4 D. 2

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

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? [A] 10K, 15K, 20K [B] 10K, 20K, 15K [C] 9K, 15K, 10K [D] 20K, 15K, 10K

c

If a particular demand paging configuration has 9 page interrupts out of 11 page requests, failure rate is ____. A) 18% B) 52% C) 82% D) 95%

c

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

c

N=4 (2316) Which of the following is not correct about user-level threads ? a. User-level threads are more efficient than kernel threads, in the sense that they do not need kernel calls to switch among threads b. User-level threads cannot be preempted by clock interrupts unless the whole process' quantum has been used up c. With user-level threads, customized scheduling algorithms cannot be implemented d. If one user-level thread makes a blocking system call, the system will block the entire process (which contains that user-level thread)

c

QN=1 (6837) 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

QN=12 In a single processor system, mutual exclusion can be guaranteed by: (2314) a. Overlapping processes b. Interleaving processes c. Disabling interrupts d. All of the above

c

QN=42 (7487) 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

QN=5 (6907) Which of the following is not a task of I/O management of OS? a. Manage main memory for the devices using caching, buffering, and spooling b. Maintain and provide a general device-driver interfaces c. Mapping files onto secondary storage d. Drivers for specific hardware devices

c

QN=50 (7523) Each device attached to your computer comes with a specia l program called a __________ that facilitates the communication between the device and the OS. a. device configurator b. translator c. device driver d. communication utility

c

QN=7 (6916) ____ is the partitioning of a single server, each of which can support a different operating system. a. Multiprocessing b. Multithreading c. Virtualization d. Shared processing

c

The cache hit ratio is ____, if the total number of requests is 10 and 6 of those are found in cache memory. A) 6% B) 10% C) 60% D) 100%

c

The page size that is too small wil l generate [A] More difficult to calculate actual position [B] Excessive internal fragmentation [C] Very long Page tables [D] Excessive external fragmentation

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

What is the characteristic of the first generation of operating system? [A] Personal computers, single user, multitasking [B] Transistors, batch systems [C] Vacuum tubes, plug boards [D] ICs and multiprogramming

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 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

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

c

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] SEEK [B] OPEN [C] RENAME [D] CLOSE

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 information bits used by the various page replacement policies indicates if the page has been called lately? a. Locality bit b. Status bit c. Referenced bit d. Modified bit

c

Which of the following instructions should be allowed only in kernel mode? [A] ADD of two numbers [B] Read the time-of-day clock [C] Disable all interrupts [D] AND of two numbers

c

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.

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

d

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

d

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

d

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

d

QN=11 (7490) Which of the following statement is not true about separating I/O and memory space? a. Device drivers must be written using assembly language b. Programs must use 2 instructions to test whether the device is ready c. There is special protection mechanism to keep user processes from performing I/O d. Caching a device control register would be disastrous

d

QN=14 (2298) Which of the following statements is incorrect about timesharing and multiprogramming systems? a. In a timesharing system, multiple users can access the system simultaneously b. In a multiprogramming system, one user can run several processes simultaneously c. All timesharing systems are multiprogramming systems d. All multiprogramming systems are timesharing systems

d

QN=14 (2319) Which is a wrong statement about the quantum used in Round Robin algorithm ? a. If the quantum is very large, RR is essentially FCFS b. If the quantum is very small, the CPU efficiency is reduced c. A reasonable value of quantum is around 20-50 ms d. None of the above

d

QN=15 (2317) Which of the following synchronization mechanisms does not rely on busy -waiting ? a. Lock variables b. Strict alternation c. Peterson's algorithm d. Semaphores

d

QN=5 (2300) Which is the difference between personal computers and mainframe computers? a. Personal computers are always interactive b. Mainframe computers are mostly batch systems with many users c. Protection is much more important on mainframe computers d. All of the above

d

QN=5 (2313) 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 above

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

d

The ____ policy is based on the theory that the best page to remove is the one that has been in memory the longest. A) TRU B) LRU C) LIFO D) FIFO

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 code 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 above

d

What are the allocation methods of disk blocks for files: a. Contiguous allocation b. Linked allocation c. Indexed allocation d. All of the above

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 cal l 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

d

What is not the technique of implementation for Virtual Memory? [A] All of the other choices [B] Paging [C] Segmentation [D] Partition

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

d

Which is not an example of a resource that is commonly time-multiplexed? a. Network interface b. CPU c. Graphics accelerator d. Main memory

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

d

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

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

d

Which of the following operating systems is an example of monolithic system? [A] Windows XP [B] Mac OS [C] UNIX [D] MS-DOS

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

d

Which of the following statements is not correct about the device controller of I/O devices? [A] Is also called adapter [B] Can handle two, four, or even eight identical devices [C] Is electronic component of device [D] Is software component of device

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 [D] Mutual-exclusion condition

d