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Worksheetsosg part 1
Total questions: 185
Worksheet time: 2hrs 33mins
1 (2299) Which of the following statements is incorrect about user mode and kernel mode?
a. In kernel mode, the OS can execute every instruction in the instruction set
b. In user mode, user program can execute only a subset of instructions
c. Having two modes of operation helps prevent user programs from accessing critical instructions
d. None of the above
2 (2302) Random Access memory:
a. Is typically faster than cache memory
b. Is volatile
c. Can only be read sequentially
d. Stores all the files on the computer
3 (2294) 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 above
4 (2292) What is the main characteristic of embedded operating system?
a. Multiple CPU
b. Time-sharing
c. Many I/O devices
d. Restriction of memory size, speed of CPU, screen size, powers
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
6 (2303) What is not correct about system calls?
a. A system call allows a user process to assess and execute operating system functions inside the kernel.
b. User programs use system calls to invoke operating system services
c. In terms of performance, using system calls is better than using procedure calls
d. Every system call involves overhead due to context switch
What is correct about trap instructions and interrupts?
A trap instruction switch the execution mode of a CPU from the user mode to the kernel mode.
A trap instruction is caused by a user program to invoke functions in the OS kernel
An interrupt is caused by an external event
All of the above
8 (2293) A Control/Status register that contains the address of the next instruction to be fetched is called the:
nstruction Register (IR)
Program Counter (PC)
Program Status Word (PSW)
All of the above
9 (2291) The general role of an operating system is to:
Act as an interface between various computers
Provide a set of services to system users
. Manage files for application programs
None of the above
10 (2290) The two basic types of processor registers are:
General and special registers
Control and Status registers
User-visible and user-invisible registers
None of the above
11 (2304) What is interrupt vector?
A signal an I/O device sends to CPU
A signal an I/O device sends to CPU
Part of memory which contains the addresses of interrupt handlers
None of the above
12 (2297) What is not a main function of an operating system?
Provide the users with an extended (virtual) machine
Manage the I/O devices
Provide user interfaces
Support virtual memory
13 (2296) Which of the following instructions should be allowed in user mode?
Disable all interrupts
Read the time-of-day clock
Set the time-of-day clock
Change the memory map
14 (2298) Which of the following statements is incorrect about timesharing and multiprogramming systems?
In a timesharing system, multiple users can access the system simultaneously
In a multiprogramming system, one user can run several processes simultaneously
All timesharing systems are multiprogramming systems
All multiprogramming systems are timesharing systems
15 (2295) MS-DOS is a example of ....
Monolithic system
Layered System
Virtual Machine
Client-server model
Which of the following statements is correct about Shortest Job First
Avoid Starvation
Minimize average waiting time
Both a and b
None of the above
2 (2310) In order to implement mutual exclusion on a critical resource for competing processes, only one program at a time should be allowed:
In the critical region of the program
To perform message passing
To exhibit cooperation
None of the above
3 (2305) Which of the following process state transitions are legal?
a. waiting -> running
b. running -> ready
c. waiting -> terminated
d. ready -> terminated
4 (2316) Which of the following is not correct about user-level threads ?
User-level threads are more efficient than kernel threads, in the sense that they do not need kernel calls to switch among threads
User-level threads cannot be preempted by clock interrupts unless the whole process' quantum has been used up
With user-level threads, customized scheduling algorithms cannot be implemented
If one user-level thread makes a blocking system call, the system will block the entire process (which contains that user-level thread)
5 (2313) What is Software proposal in the solution of Mutual exclusion with Busy waiting
Lock Variables
Strict Alternation
Peterson's Solution
All of the above
6 (2318) Which of the following is a preemptive scheduling algorithm
FCFS
Shortest Job First
Round Robin
None of the above
7 (2308) The scheduling strategy where each process in the queue is given a certain amount of time, in turn, to execute and then returned to the queue, unless blocked is referred to as:
Prioritization
Round-Robin
LIFO
All of the above
8 (2307) Which of the following process state transitions are illegal?
Ready-> running
waiting -> running
running -> ready
running -> terminated
9 (2312) The following requirement must be met by any facility or capability that is to provide support for mutual exclusion:
Only one process at a time can be allowed into a critical code section
A process remains in its critical region for a finite time only
No assumption can be made about relative process speeds
All of the above
10 (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
11 (2306) Which of the following cannot be shared among different threads of a process?
Process code
File handles
Process data
Stack
12 (2314) In a single processor system, mutual exclusion can be guaranteed by:
Overlapping processes
Interleaving processes
Disabling interrupts
All of the above
13 (2315) Which is not a goal of a scheduling algorithm for batch systems ?
Fairness
Throughput
Turnaround time
Response time
14 (2319) Which is a wrong statement about the quantum used in Round Robin algorithm ?
If the quantum is very large, RR is essentially FCFS
If the quantum is very small, the CPU efficiency is reduced
A reasonable value of quantum is around 20-50 ms
None of the above
15 (2317) Which of the following synchronization mechanisms does not rely on busy-waiting ?
Lock variables
Strict alternation
Peterson's algorithm
Semaphores
1 (2531) 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
2 (2534) Which of the following is appropriate to release page table and pages?
Process creation
Process execution
Page fault time
Process termination time
3 (2537) Page replacement algorithms determine
when the system should update page table entries
how many pages should be added to main memory
which pages should be brought into memory because a process is likely to reference them soon
which page to remove to provide space for an incoming page
4 (2530) The page table for each process maintains:
The 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 above
5 Which of the following information bits in the entry of page table is used to indicate Page(2529) Fault?
Present/absent bit
Status bit
Referenced bit
Modified bit
The second-chance page-replacement algorithm
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
Searches through a circular list of pages and replaces the first page it encounters that has the referenced bit turned off
Relies on a modified bit to determine which page to replace
None of the above
7 (2533) Which of the following information bits used by the various page replacement policies indicates if the page has been called lately?
Locality bit
Status bit
Referenced bit
Modified bit
When a virtual memory system manages memory in fixed length units, which of the following terms correctly represents its unit?
Frame
Page
Sector
Segment
In terms of speed the best method of Dynamic Storage-Allocation is:
Next fit
First fit
Best fit
Worst fit
The actual location in main memory is called a(n):
Relative address
Logical address
Absolute address
None of the above
LRU replaces the page that has spent the
longest time in memory
longest time in memory without being referenced
shortest time in memory
shortest time in memory without being referenced
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 above
The task of subdividing memory between the OS and processes is performed automatically by the OS and is called
Protection
Relocation
Memory Management
All of the above
Which of the following is appropriate to determine program size and create page table?
Process creation
Process execution
Page fault time
Process termination time
What is the method to keep track of memory usages?
Memory Management with Bit Maps
Memory Management with Linked Lists
a and b
None of the above
The special files are:
character special file
block special file
Neither a nor b
Both a and b
Which of the following is true about the block size in disk space management
the larger the block size is the lower the data rate is
he larger the block size is the worse the disk space utilization is
the larger the block size is lesser the disk space is
none of the above
A file is generally defined to be:
A basic element of data
A collection of related fields
A collection of similar records
All of the above
Which of the following is not a path name for the file /etc/passwd
/etc/passwd
/etc/../etc/passwd
/etc/../etc/../etc/passwd
None of the above
What are the allocation methods of disk blocks for files:
Contiguous allocation
Linked allocation
Indexed allocation
All of the above
File Structure can be:
byte sequence
record sequence
tree
All of the above
What is incorrect about contiguous allocation of files ?
It is simple to implement
It leads to excellent read performance
It does not cause disk fragmentation
It is widely used on CD-ROMs
The i-nodes are used in which of the following allocation methods
Contiguous allocation
Linked allocation
Indexed allocation
Linked allocation using FAT
Which of the following is specified to indicate the directory where the file is located?
Extension
Path name
Root directory
Sub-directory
Which of the following is not correct about hard links and symbolic links?
Symbolic links need space to store the name and the file pointed to
Hard links do not require extra disk space
Symbolic links can point to files in the network
Hard links can point to files on other machines
Device Driver is normally written by:
Device's Manufacturer
OS's Manufacturer
Computer's Manufacturer
All of the above
Which of the following I/O software device layers is done by user-level software?
Computing the track, sector, and head for a disk read
Writing commands to the device registers
Checking to see if the user is permitted to use the device
Converting binary integers to ASCII for printing
An example of the key differences that can exist across (and even in) classes of I/O devices is:
Data rate
Data representation
Error conditions
All of the above
In general, which is the best technique for I/O Data transfer?
Programmed I/O
Interrupt-Driven I/O
Direct Memory Access
None of the above
Which of the following statements is not correct about DMA ?
DMA controller has access to the system bus independent of the CPU
DMA helps reduce the number of interrupts (in comparison with interrupt-driven I/O)
DMA controller is usually faster than CPU
The operating system can only use DMA if the hardware has a DMA controller
Which of the following is not correct about the reliability of different RAID levels?
There is no reliability support in RAID level 0
All RAID levels can survive one disk crash
In RAID level 2, a single bit error in a word can be detected AND corrected
n RAID levels 3, 4, 5 a single bit error in a word can be detected
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
What kind of I/O devices that disks and tapes belong to?
Stream-oriented devices
Block-oriented devices
Character-oriented devices
None of the above
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 character-oriented I/O device
None of the above
he 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 above
The system is said to be in an unsafe state if
The operating system cannot guarantee that all current processes can complete their work
The system is deadlocked
A process is indefinitely postponed
None of the above
f in a resource-allocation graph, each resource type has exactly one instance, which of the following indicate a deadlock situation?
The graph has at least one cycle.
The graph has no cycle.
The graph is connected
The graph is not connected.
All deadlocks involve conflicting needs for resources by
One or more processes
Two or more processes
Three or more processes
None of the above
What is the characteristic of deadlocked systems
Starvation
Circular wait
Saturation
Aging
A possibility of deadlock can occur:
If a system is in safe state
If a system is in unsafe state
If a system is in instable state
None of the above
What is the weakness of the Banker's algorithm?
Allowing the population of processes to vary over time
Enabling processes to hold their resources indefinitely
Requiring that processes state their maximum needs in advance
Enabling the number of resources to fluctuate
he permanent blocking of a set of processes that compete for system resources is called
Starvation
Deadlock
Prioritization
All of the above
Which of the following is not a condition necessary for deadlock to exist?
mutual-exclusion condition
circular-wait condition
hold and wait condition
preemption condition
Dijkstra's Banker's Algorithm require the system to maintain the resource information for each process, including:
a. A count of the system's total resources
b. The maximum resources that can be requested by the process
c. The number of resources currently acquired by the process
d. B and C
If a deadlocked system, the processes can
run
release resources
be awakened
do nothing
What is the characteristic of the first generation of operating system?
Personal computers, single user, multitasking
Transistors, batch systems
Vacuum tubes, plug boards
ICs and multiprogramming
Which is not an example of a resource that is commonly time-multiplexed?
Graphics accelerator
Network interface
Main memory
CPU
Which of the following is an Operating System component?
Process Management
Speed Management
Space Management
Time Management
Which of the following conditions that causes the processes to be terminated, when processes have done their work?
Fatal error (involuntary)
Normal exit (voluntary)
Killed by another process (involuntary)
Error exit (voluntary)
Which of the following statements is a hardware solution to the critical region problem?
Semaphore
TSL|
None of the other choices
Shared memory
Which of the following process state transitions is correct, when the scheduler picks a process fromthe ready queue to run?
Ready -> running
Running -> Blocked (waiting)
Blocked (waiting) -> ready
Running -> ready
Which cannot be able to solve the race condition?
TSL
Shared memory
Semaphore
Monitor
Which of the following statements about semaphores is true?
A semaphore implementation should guarantee that processes do not suffer indefinite postponement,
P and V (Down and Up) operations should be indivisible operations
All of the other choices
If several processes attempt a P(S) operation simultaneously, only one process should be allowed toproceed
Which of the following process state transitions is illegal?
Ready -> Blocked (waiting)
Running -> Blocked (waiting)
Blocked (waiting) -> ready
Running -> ready
In order to implement mutual exclusion on a critical resource for competing processes, only one program at a time should be allowed:
None of the other choices
In the critical region of the program
To exhibit cooperation
To perform message passing
Critical Region (Section) concept used in interprocess communication is:
A part of shared memory
A part of the program where the shared memory is accessed
None of the other choices
A part of shared data
Which of the following statements is incorrect about timesharing and multiprogramming systems?
Al l timesharing systems are multiprogramming systems
In a timesharing system, multiple users can access the system simultaneously
All multiprogramming systems are timesharing systems
In a multiprogramming system, one user can run several processes simultaneously
Which of the following instructions should be allowed only in kernel mode?
AND of two numbers
ADD of two numbers
Read the time-of-day clock
Disable all interrupts
What is an operating system structure in which the communication between requesting process and responding process is message passing?
Monolithic Systems
All of the other choices
MS-DOS
Client-Server Model
The language ofthe CPU is known as its
Register set
Control unit set
Instruction set |
None ofthe other choices
Linux and are often used as operating systems on supercomputers, mainframes, and servers.
UNIX
Windows
None ofthe other choices
Mac OS
A well-known Real-Time operating system is:
MS-DOS
e-COS
TinyOS
Personal Operating System
Which ofthe following operating systems is an example of monolithic system?
Windows XP
Mac OS
UNIX
MS-DOS
Where is the position of the operating system in computer system:
Between the user interface program and the application Program
None of the other choices
In user space
Above the hardware and under the user interface program
The is the essential component ofthe operating system that remains in RAM when your computer is powered on.
registr y
kernel
system file
What is correct about trap instructions and interrupts?
Trap instruction switches the execution mode of a CPU from the user mode to the kernel mode.
A trap instruction is caused by a user program to invoke functions in the OS kernel
An interrupt is caused by an external event
All ofthe other choices
The _________is the essential component ofthe operating system that remains in RAM when your computer is powered on.
system file
kernel
registry
Which of the following instructions should be allowed only in kernel mode?
ADD of two numbers
Read the time-of-day clock
Disable all interrupts 1
AND of two numbers
Consider a computer system that has cache memory, main memory (RAM) and disk, and OS uses virtual memory. It takes 2 nsec to access a byte from the cache. 20 nsec to access a byte from RAM. and 10 msec toaccess a block of 1000 bytes from the disk. If a book has 1000 pages, each with 50 lines of 80 characters each. How long it will take to electronically scan the textfor the case of the master copy being in each of the level asone proceeds down the memory hierarchy (from inboard memory to offline storage)?
1 msec. 10 msec. 10 sec
4 msec. 40 msec. 20 sec
2 msec. 20 msec. 10 sec
1 msec. 10 msec. 5 sec
The basic idea behind the microkernel design is:
All ofthe other choices
All other modules run as relatively powerless ordinary user processes
Only one module runs in kernel mode
To archive high reliability by splitting operating system up into small, well-defined modules
Which is not a goal of a sheduling algorithm for all systems?
Balance
Response time
Policy enforcement
Fairness
Which of the following statements about semaphores is true?
A semaphore implementation should guarantee that processes do not suffer indefinite postponement,
P and V (Down and Up) operations should be indivisible operations
All of the other choices
If several processes attempt a P(S) operation simultaneously, only one process should be allowed toproceed.
Critical Region (Section) concept used in interprocess communication is:
A part of shared memory
A part of the program where the shared memory is accessed
None of the other choices
A part of shared data
Which conditions of mutual exclusion does the Lock Variables (Software proposal) violate?
No process must wait forever to enter its critical region
No two processes simultaneously in critical region
No process running outside its critical region may block another process
No assumptions made about speeds or numbers of CPUs
A entry of the Process table is called:
All of the other choices
Process check block
Process management block
process control block.
Semaphores that are initialized to 1 and used for two or more processes to ensure only one can enterits critical section at the same time are called:
None of the other choices
Binary semaphores
Integer semaphores
Counter semaphores
An arrival message causes the system to create a new thread to handle this message. This newthread is call
Upcall
Distributed
Activator
Pop-up
How many ways is Thread implemented?
1
3
2
None of the other choices
Which of the following is not a CPU scheduling criterion?
Burst time
CPU utilization
Throughput
Response time
How many percent of the CPU time is wasted, when a computer system has enough room to hold twoprogram and these programs are idle waiting for I/O 10% of the time?
90%
99%
None of the other choices
1 %
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 CPUutilization when these programs are idle waiting for I/O 20% of the time?
4%
90%
None of the other choices
96%
To specify an address in this segmented memory, the form is used
<physical address, offset>
<process, offset>
<segment-number, offset>
<virtual address, offset>
Where should be put the page replacement algorithm In Mach model of Page fault handling with anexternal pager?
All of the other choices
In the low-level MMU handler
In the external pager running in user space
In the page fault handler that is part of the kernel
One of the most important innovations of demand paging was that it made feasible
Virtual paging
Virtual memory.
Memory demand
Virtual demand
Which of these statements about the algorithm "Next fit" is true?
Memory Manager searches the entire list of segments from beginning to end and take smallest holethat is adequate.
Memory Manager scans along the list of segments until it finds a hole that is big enough.
Memory Manager starting searching the list of segments from the place where it left off last time
None of the other choices
If there are 64 pages and the page size is 2048 words, what is the length of logical address?
17 bits
15 bits
16 bits
14 bits
The __________ policy is based on the theory that the best page to remove is the one that has been in Thememory the longest
FIFO
LIFO
LRU
NRU
Which of the following information bits in the entry of page table is used to indicate Page Fault?
Status bit
Present/absent bit
Referenced bit
Modified bit
Consider a swapping system in which the memory consists of the following hole sizes: 10 K, 4 K, 20 K, 15K, 9 K. Assume first fit algorithm is used. Which holes are taken for successive segment requests of 8 K, 12K, 10 K?
9 K, 15 K, 10 K
10 K, 20 K, 15 K
20 K, 15 K, 4 K
None of the other choices
When a virtual memory system manages memory in fixed length units, which of the following termscorrectly represents its unit?
Page
Frame
Block
Segment
Which of the following statements is incorrect about Translation Look-aside Buffer (TLB)?
None of the other choices
A TLB is sometimes known as an associative memory
A TLB miss implies a disk operation will follow
Each entry of a TLB contains the information about one page, including the virtual page number andthe corresponding page frame
When there is an excessive amount of page swapping between main memory and secondarystorage, the operation becomes inefficient, which is called .
thrashing
Over swapping
hot swapping
excessive demand paging
n 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
Worse
Better
Nearly equal
Equal
When a virtual memory system manages memory in fixed length units, which of the following termscorrectly represents its unit?
Block
Page
Frame
Segment
Which of the following is correct about symbolic links?
Symbolic links can only point to files on the same machines
None of the other choices
Symbolic links need not space to store the path name
Symbolic links can point to files in the network
is a specialized WRITE command for existing data files that allows for appending records or forrewriting selected records in their original place in the file.
UPDATE
REWRITE
MODIFY
APPEND
Many computer users and some operating systems call subdirectories
Volumes
Databases
Folders
Files
Which method is used to implement files to keep each file as a linked list of disk blocks?
Contiguous Allocation
i-node
File Allocation Table
Linked List Allocation
Which of the following allocation methods, Operating system MS-DOS is implemented?
Linked allocation using FAT
Indexed allocation
Linked allocation
Contiguous allocation
Which of a system call is to allow the system announce that the file is coming and set some of theattributes?
CREATE
RENAME
OPEN
CLOSE
Which of a system call is to allow the file to appear in more than one directory?
CREATE
LINK
OPEN
SEEK
Which of a system call is to allow the system free up internal table space?
SEEK
OPEN
Close
DELETE
What is incorrect about contiguous allocation of files?
It leads to excellent read performance
It does not cause disk fragmentation
It is widely used on CD-ROMs
It is simple to implement
Which of the following is not special file?
None of the other choices
Block special file
Character special file
Stream special file
Disk can be divided up into one or more partitions. The first block of every partition is called:
Super block
Free block
MBR
Boot block
What is a "stripping" in RAID?
Take away possessions from someone
Get undressed
All of the other choices
Distributing data over multiple drives
How much cylinder skew is needed for a 5400- RPM (rotate per minute) disk with the track-to-trackseek time of 1 msec? The disk has 200 sectors of 512 bytes on each track.
18 sectors
12 sectors
24 sectors
36 sectors
The aspect of disk performance that represents the time it takes to position the head a the desiredtrack is known as
Rotational delay
Access time
Seek time
None of the other choices
A operation concerning Stable Storage is:
Stable Reads
All of the other choices
Crash recovery
Stable writes
When making CDs for sale, such as music or software CDs, data is recorded on a master disc bymeans of a high-intensity laser beam, which burns indentations, called pits, and flat areas, called
Lakes
Lands
Valleys
Hills
Rearrange the layers in I/O software starting at the bottom1. User-level I/O software2. Device drivers3. Interrupt handlers4. Hardware5. Device-independent OS software
12345
54321
15234
43251
When an external device becomes ready to be serviced by the processor, the device sends thissignal to the processor. This signal is called:
None of the other choices
Halt signal
Interrupt signal
Handler signal
Imagine that a certain modem can read 7,000 characters per second and that the time to read acharacter 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. Howmany percent of the CPU does the interrupt overhead cost?
4% of the CPU
7% of the CPU
96% of the CPU
93% of the CPU
Assuming that it takes 10 nsec to copy a byte, how much time does it take to completely rewrite thescreen of a 1200 x 800 pixel graphics with 24- bit color?
288 msec
288 micro-sec
28.8 micro-sec
28.8 msec
What is asynchronous transfer in principles of I/O software?
The user process makes system call and goes to sleep until other process it wakes up
None of the other choices
The user program starts system call to transfer and automatically suspended until the data are available in the buffer
The CPU starts the transfer and goes off to do something else until the interrupt arrives
Assuming that it takes 10 nsec to copy a byte, how much time, does it take to completely rewrite the screen of a 200 characterx 20 line text mode memory-mapped screen?
10 micro-sec
30 micro-sec
40 micro-sec
20 micro-sec
Which of the following statements is incorrect about I/O using DMA?
None of the other choices
DMA helps free up the CPU during the I/O to do other work
DMA helps reduce the number of interrupts
DMA is software solution to speed up data transfer between I/O device and memory
Which is not a function of device drivers?
To manage its power requirements and log events
To accept abstract read and write request from device independent software above it and see that they are curried
To receive system call
To initialize the device, if needed
The term__________a specialized instruction set.
None of the other choices
I/O device
DMA
Programmed I/O
In a directed graph used to model deadlock, ______represents deadlock.
Dashed arrow
Solid arrow
Any path
Cycle
is when, in modern printing systems, a disk accepts output from several users and acts as atemporary storage area for all output until the printer is ready to accept it
Lagging
Spooling
Spoofing
Buffering
In a directed graph used to model deadlock, resources are represented using
Rectangle
Circular
Squares.
Ellipse
What is the correct approach with the "Mutual Exclusion condition" to prevent Deadlock?
Take resources away
Request all resources initially
Spool everything
Order resources numerically
Which deadlock condition does "Ordering resources numerically" attack?
No preemption
Circular-wait condition
Hold and wait
Mutual exclusion
Which deadlock condition does "Take resources away" attack?
Circular-wait condition
No preemption
Hold and wait
Mutual exclusion
Which method is used to prevent the communication deadlock?
All of the other choices
Timeouts
Handling alarm
Acknowledge signal
_________is the act of allowing only one process to have access to a dedicated resource
Hold and wait condition
No preemption condition
Circular-wait condition
Mutual-exclusion condition
What is the correct approach of the driver of dedicated devices with requesting device that is busy tosolve deadlock using Ostrich algorithm?
The device driver stops the current jobs and releases the devices
The device driver kills those requesting processes
All of the other choices
The device driver decides blocking and returning an error code
An example of preemptable resources is
DVD device
None of the other choices
CD-ROM device
Memory
What is true about non-preemptable resources?
Can be taken away from a process with no ill effects
None of the other choices
Will cause the process to fail if taken away
Can share among processes
______allows a resource to be held by a process as long as it is needed
Hold and wait condition
Mutual-exclusion condition
No preemption condition
Circular-wait condition
Which of the following is not a step in the boot process?
The antivirus program checks all files for viruses.
Configuration and customization settings are checked
The operating system is loaded into RAM.
The BIOS is activated by powering on the CPU.
Which of a system call is to allow the system free up disk space?
OPEN
CLOSE
SEEK
DELETE
A________is a group of related records that contains information to be used by specific application programs to generate reports.
Field
File
Record group
Directory
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
6785
7600
10250
A ____ is a portion of a process that can run independently.
subprocess
thread
program
Mini-process
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?
SEEK
OPEN
RENAME
CLOSE
Which of the following actions generates an external interrupt?
A page that does not exist in the main memory is accessed by the virtual storage management.
An input/output operation is completed.
Division by zero occurs.
A system call instruction is executed.
Deadlock definition:A set of processes is deadlocked if each process in the set is waiting for an event that only another process in the set can cause. What does event mean?
The event is release of a currently held resource
The event is some mouse click
The event is press some key on keyboard
None of the other choices
An interrupt that leaves the machine in well-defined state is called a(n)
Precise interrupt
Disappointed interrupt
Required interrupt
Imprecise interrupt
Which of following statements about the memory hierarchy is false?
Small amount of fast expensive memory - cache
Gigabytes of slow cheap disk storage
None of the other choices
Some medium-speed medium price main memory
Which is the fastest bus in the IBM PC computer
ISA
USB
IDE
PCI
Which of the following statement is correct about a disadvantage of memory-mapped I/O?
Caching a device control register would be disastrous
Programs can use 1 instructions to test whether the device is ready
Since the control registers of devices are mapped into the memory space, device drivers can be written in C
No special protection mechanism needed to keep user processes from performing I/O
As one proceeds down the memory hierarchy (from inboard memory to offline storage), the following conditions apply:
Increasing capacity
Decreasing cost per bit
All of the other choices
Increasing access time
Which classes of I/O devices that Clock belong to?
Stream devices
Block devices
Character devices
None of the other choices
Which of the following statements is not correct about the device controller of I/O devices?
Is also called adapter
Can handle two, four, or even eight identical devices
Is electronic component of device
Is software component of device
What is not the technique of implementation for Virtual Memory?
All of the other choices
Paging
Segmentation
Partition
In the memory-mapped I/O system, in order that CPU communicates with the control registers in the devices, the control register is assigned :
Index
Unique memory address
I/O address
None of the other choices
Which of special register contains the condition code bits, the CPU priority, the mode bit and other control bits
Program Status Word (PSW)
None of the other choices
Instruction Register (IR)
Program Counter (PC)
_________is when each process involved in the impasse is waiting for another to voluntarily release the resource so that at least one wil l be able to continue on.
Hold and wait condition
No preemption condition
Mutual-exclusion condition
Circular-wait condition
Which of these statements about the algorithm "Worst fit" is true?
Memory Manager starting searching the list of segments from the place where it left off last time.
Memory Manager scans along the list of segments until it finds a hole that is big enough.
Memory Manager searches the entire list of segments from beginning to end and take smallest hole that is adequate.
None of the other choices
The aspect of disk performance that represents the time it takes to position the head a the desiredtrack is known as
Rotational delay
Access time
Seek time
None of the other choices
How many categories can be the I/O devices roughly divided?
1
2
3
4
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
The disk blocks in a partition that contains the top of the file system tree is called:
Free space management blocks
Root directory
Boot block
Superblock
