What is not a main structural element of a computer system?
Processor
Main Memory
I/O Modules
System Bus
Operating system
Which of the following registers are used by the processor to exchange data with memory?
MAR and MBR
PC and IR
Program status word
I/OAR and I/OBR
Which of the following registers are used by the processor to exchange data with input/output module?
Which of the following element of a computer system controls the operation of the computer and performs its data processing functions?
System bus
Main memory
I/O modules
Which of the following element of a computer system stores data and programs?
Which of the following provides for communication among elements of a computer system?
Which of the following element of a computer system moves data between the computer and its external environment?
The processor contains a single data register, called
PSW
PC
IR
AC
This register specifies a particular input/output device
Memory address register
I/OAR
Memory buffer register
I/OBR
This register is used for the exchange of data between an I/O module and the processor
This register contains the data to be written into memory or which receives the data read from memory
memory buffer register
memory address register
This register specifies the location in memory for the next read or write
Index register, segment register, and stack register are example of:
Address register
Data registers
Control registers
Status registers
Which register contains the address of the next instruction to be fetched?
instruction register
execution register
program counter
process counter
Which register contains the instruction most recently fetched?
Which register contains condition codes set by the processor hardware as the result of operations?
Program counter
Accumulator
Stack pointer
The fetched instruction is loaded into the
Memory
At the beginning of each instruction cycle, the processor fetches an instruction from the memory. The address of the instruction is held in
MBR
MAR
The processor is executing ‘Load AC from memory’ instruction. Choose the correct micro-instructions:
PC -> MAR M -> MBR MBR -> AC IR -> MAR M -> MBR MBR -> AC
PC -> MBR M -> MAR MAR -> IR IR -> MAR M -> MBR MBR -> AC
PC -> MAR M -> MBR MBR -> IR IR -> MAR M -> MBR MBR -> AC
PC -> MAR M -> MBR MBR -> IR IR -> MBR M -> MAR MAR -> AC
When an I/O device completes an I/O operation, the device issues an interrupt signal to the processor and then:
The processor stops execution of the current instruction without finishing it and responds to the interrupt
The processor loads the program counter with the entry location of the interrupt-handling routine
The processor saves information needed to resume the current program at the point if interrupt
The processor finishes execution of the current instruction before responding to the interrupt
When the time required for the I/O operation is less that the time to complete the execution of instructions between write operations in the user program, it is:
Fast I/O wait
Slow I/O wait
Long I/O wait
Short I/O wait
When the time required for the I/O operation will take much more time than executing a sequence of user instructions, it is
Most I/O devices are:
much slower than the processor
much faster than the processor
much shorter than the processor
much longer than the processor
If there no interrupts, after each write operation, the processor must
Load new PC value
Finish execution of current instruction
Save the PSW and PC onto control stack
Pause and remain idle until the I/O operation finishes
Complete the relationship concerning the memory systems: faster access time –
lower capacity
greater cost per bit
faster access speed
smaller cost per bit
Complete the relationship concerning the memory systems: greater capacity –
slower access time
The smaller, more expensive, faster memory is:
Disk drive
Cache
Register
If the accessed word is found in the faster memory, that is defined as a:
bingo
win
hit
evrika
If the accessed word is not found in the faster memory, that is defined as a:
ricochet
miss
zero
Loss
The central idea in this system was the use of a piece of software known as the monitor
Time-sharing-system
Simple batch system
Multiprogrammed batch system
Serial processing
The concept of a batch operating system was developed to
Maximize processor utilization (To improve utilization)
Minimize response time
Support interactive mode
Minimize processor utilization
The concept of modes of operation (user mode, system mode) was introduced with
'Ease of evolution of an OS' corresponds to the following objective:
Efficiency
Convenience
Ability to evolve
The principal objective of the time-sharing system is to
Maximize response time
Maximize processor utilization
The processor was often idle waiting for the I/O instruction to conclude. To overcome the problem the following approach was introduced: when one job needs to wait for I/O, the processor can switch to the other job. This was a
Multiprogramming or multitasking batch system
The programmer interacted directly with the computer hardware with
Simple batch systems
Time-sharing-systems
Multiprogrammed batch systems
Semaphore is a/an_to solve the critical section problem?
integer variable
special program for a system
complex structure
hardware for a system
'The OS as a resource manager' corresponds to the following objective:
An un-interruptible unit is known as:
atomic
none of the above
static
single
A state is safe, if:
the system can allocate resources to each process in some order and still avoid a deadlock
the system does not crash due to deadlock occurrence
all of the above
the state keeps the system protected and safe
'The OS as a User/Computer interface' corresponds to the following objective:
This type of memory is nonvolatile
Secondary memory
An application programs is developed by the
Application programmer
End user
Hardware
When a processor attempts to read a byte or word of memory, it firstly checks the:
The end user views a computer system in terms of
a set of applications
a set of machine instructions
utilities
a set of system programs
The serial processing presented two main problems:
setup time
using a monitor
time slicing
multiprogramming
scheduling
The hardware and software used in providing applications to a user can be viewed in a:
layered fashion
classified fashion
sandwich fashion
leveled fashion
A situation where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which access takes place is called:
data consistency
mutual exclusion
race condition
starvation
This contains the most frequently used functions in the OS:
Kernel (или nucleus)
Centre
Base
Root
The initial value of the semaphore that allows only one of the many processes to enter their critical sections,is?
1
10
2
0
Utilities are
Application program
System programs
Opcodes
Processor registers
Block size is:
The unit of data exchanged between cache and main memory
Larger block size yields more hits until probability of using newly fetched data becomes less than the probability of reusing data that have to be moved out of cache
(How much data should be transferred from main memory to cache)
There were no OS with
Which of the following cannot be interrupted?
Process
Thread
Module
Atomic operation
Process is
a unit of activity characterized by execution of a sequence of instructions, a current state, and an associated set
a job in secondary memory
contents of main memory
program in high level language kept on disk
This determines which cache location the block will occupy:
This resource can be created and destroyed
resumable resource
restartable resource
consumable resource
finite resource
This system handles multiple interactive jobs
Process(2.0) is:
A program in execution
Program in High level language kept on disk
Contents of main memory
A job in secondary memory
This system was developed by General Motors for the use on an IBM 701
Simple Batch Systems or GM-NAA I/O
Time-sharing system
This chooses which block to replace when a new block is to be loaded into the cache and the cache already had all slots filled with other blocks
replacement algorithm
write policy
cache size
locality of reference
Four necessary conditions for deadlock to exist are: mutual exclusion, no-preemption, circular wait and
hold and wait
deadlock avoidance
A task in a blocked state
is waiting for same temporarily unavailable resources
must still be placed in the run queues
is executable
is running
This type of system was developed at MIT by a group known as Project MAC for the IBM 709 in 1961
This resource can be safely used by only one process at a time and is not depleted by that use
refurbished resource
replenishing resource
reusable resource
refreshing resource
If the contents of a block in the cache are altered, then it is needed to save it back to main memory before replacing it. This is called:
mapping function
'Lost signals, duplicate signals received'. This is
Improper synchronization
Nondeterminate program operation
Failed mutual exclusion
Deadlocks
The systems which allows only one process execution at a time, are called
uniprogramming systems
unitasking systems
uniprocessing systems
unicasting systems
Deadlock inevitable region can be referred to as a
fun region
fatal region
final region
false region
In the non-blocking send, non-blocking receive:
the sending process keeps sending until it receives a message
the sending process sends the message and resumes operation
neither of processes are required to wait
the sending process keeps sending until the message is received
Which of the following is not a technique possible for I/O operations?
Direct memory access (DMA)
Manual memory access
Interrupt-driven I/O
Programmed I/O
'Two or more programs hung up waiting for each other'. This error is caused by
Falled mutual exclusions
This illustrates the progress of two processes competing for two resources
joint process diagram
joint ingres diagram
joint regress diagram
joint progress diagram
The processor issues an I/O command to a module and waits, periodically checking the status of the I/O module until it finds that the operation is complete.
A monitor is a type of:
deadlock
low level synchronization construct
high level synchronization construct
The state of a process is defined by:
the current activity of the process
the activity to next be executed by the process
the final activity of the process
the activity is just executed by the process
'When programs share memory and their execution is interleaved by the processor, they may interfere with each other by overwriting common memory areas in unpredictable ways. The results of a particular program depend on the activities of other programs in a shared system'. This is
Improper syncronization
The I/O module performs the requested action and then sets the appropriate bits in the I/O status register but takes no further action to alert the processor.
When each process in the set is blocked awaiting for resource siezed by another blocked process
it is a deadend
it is a deadlock
it is a softlock
it is a mortallock
Which of the following is not the state of a process?
Old
terminated
running
new
ready
The described technique is:
Choose the storage management responsibility for "Many application programs require means for storing information for extended periods of time, after the computer has been powered down"
Long-term storage
Protection and access control
Automatic allocation and management
Process isolation
Support of modular programming
Suppose that a process is in “Blocked” state waiting for some I/O service. When the service is completed, it goes to the:
Ready state
Running state
Terminated state
Suspended state
Which of the following statements is false:
compaction does not involve relocation of programs
the technique of storage compaction involves moving all occupied areas of storage to one end or other of main storage
compaction is also known as garbage collection
the system must stop everything while it performs the compaction
Choose the storage management responsibility for "Programmers should be able to define program modules, and to create, destroy, and alter the size of modules dynamically"
Which of the following state transitions is not possible?
blocked to running
running to blocked
blocked to ready
ready to running
The main disadvantage of this technique: it is a time-consuming process that keeps the processor busy needlessly.
Memory is:
is the device where information stored
is a sequence of the instructions
is a device that performs a sequence of operations specified by instructions in memory
is typically characterized by interactive processing and time-slicing of the CPU’s time to allow quick response to each user
Choose the storage management responsibility for "The OS can achieve efficiency by assigning memory to jobs only as needed"
If a process is executing in its critical section, then no other processes can be executing in their critical section. This condition is called
asynchronous exclusion
critical exclusion
synchronous exclusion
The processor issues an I/O command to a module and then go on to some other useful work.
Processor is:
Choose the storage management responsibility for "The OS must allow portions of memory to be accessible in various ways by various users"
Interprocess communication:
allows processes to communicate and synchronize their actions without using the same address space
allows processes to communicate and synchronize their actions when using the same address space
allows the processes to only synchronize their actions without communication
The I/O module performs the requested action and alerts the processor to request service when it is ready to exchange data with the processor
Choose the storage management responsibility for "The OS must prevent independent processes from interfering with each other's memory, both data and instructions"
Program is:
A sequence of instructions, in a computer language, to get the desired result, is known as?
program
process
instruction
algorithm
In operating system security and protection, authenticity:
Concerned with the proper verification of the identity of users and the validity of messages or data
Assuring that users cannot read data for which access is unauthorized
Protection of data from unauthorized modification
Concerned with protecting the system against interruption
The main disadvantage of this technique: consumes a lot of processor time, because every word of data that goes from memory to I/O module or from I/O module to memory must pass through the processor
In operating system, each process has its own:
all of the mentioned
address space and global variables
set of data
program code
The memory allocation scheme subject to "external" fragmentation is?
segmentation
swapping
multiple contiguous fixed partitionings
pure demand paging
In operating system security and protection, availability is:
For each process OS creates and manages:
Process control block
Program code
Program
Thread control block
The processor issues an I/O command to a separate module, by sending the type of operation (read/write), the address of the I/O device, the starting location in memory for data, number of words. Then the processor continues with other work.
The memory allocation scheme subject to "internal" fragmentation is?
In operating system security and protection, confidentiality is:
The module transfers the entire block of data to/from memory without going through the processor.
The available vector defines
total amount of each resource NOT allocated to any process
total amount of each resource allocated to all processes
total amount of each resource in the system
total amount of resources required for all processes
Any program, no matter how small, will occupy an entire partition results in?
internal fragmentation
paging
external fragmentation
In operating system security and protection, data integrity is:
The main disadvantage of this technique: there is a competition for bus usage
A binary semaphore is a semaphore with integer values:
0,5
-1
The resource vector define
A hardcopy sign-up sheet was used to reserve computer time with
Time slicing
Time sliding
Time scheduling
Time allocating
Short-term scheduler, or dispatcher, picks a process. Each process in the queue is given some time in turn. This strategy is called:
Round-robin technique
Prioritizing
Carousel technique
Merry-go-round technique
This matrix defines the current allocation to process i of the resource j
Allocation matrix
Resource matrix
Request matrix
Claim matrix
A system clock generates interrupts at a rate of approximately one every 0.2 seconds. At each clock interrupt, the OS regained control and could assign the processor to another user. This technique is known as
The base register
Defines the size of the region of (in bytes or words)
Contains the index into the process list of the process currently controlling the processor
Points to the next instruction in that process to be executed
Contains the staring address of the region of memory occupied by the process
The two atomic operations permissible on semaphores are:
hold
stop
signal
wait
This matrix defines the amount of resources of type j requested by process i
How to solve problem of equal-size partitions? swapping (?) ----- page 318 book
swapping (?) ----- page 318 book unequal-size partitions
compaction
virtual memory segmentation
The limit register
Batch operating systems were used (years)
From the late 1940s to the mid-1950s
From the mid-1950 to early 1960s
In early 1960s
This matrix defines requirements of processes i for the resources j
How to solve problem of "external" fragmentation?
larger memory space
smaller memory space
none of these
The principal tool available to system programmers in developing the early multiprogramming and multiuser interactive systems
Interrupt
Job control language
Monitor
Add hec method
The banker's algorithm is referred to as
resource allocation denial
denial of service
loan allocation denial
resource allocation refusal
A page fault?
occurs when a program accesses a page of memory
is a reference to a page belonging to another program
is an access to a page not currently in memory
is an error is a specific page
Job control language was used
used to provide instructions to the monitor,In early 1960s
From late 1940s to the mid-1950s
From the mid-1950s to early 1960s
Execute instructions
Control the sequence of events as the resident monitor
Translate the user’s program into object code
Provide instructions to the monitor to improve job setup time
The process index register
Contains the index into a process list of the process currently controlling the processor
Define the region in memory occupied by the process
Contains the starting address of the region of memory occupied by the process
Which of the following condition is required for deadlock to be possible
a process may hold allocated resources while awaiting assignment of other resources
no resource can be forcibly removed from a process holding it
'Hold and wait' condition for deadlock is defined as
Process holds a resource while awaiting for other resource
Each process holds resource needed by next process in chain
No resource can be forcibly removed from process holding it
Only one process may use a resource at a time
Serial processing was used
This term was first used by the designers of Multics in the 1960s
Multiprogramming
Time sharing
Which of the following statements is false?
I\O transfers are more efficient with large pages
a large page size causes instructions and data that will not be referenced brought into primary storage
a small page size causes large page tables
internal fragmentation is increased with small pages
Banker’s algorithm for resource allocation deals with:
deadlock recovery
deadlock prevention
'Circular wait' condition for deadlock is defined as
Swapping
allows many programs to use memory simultaneously
allows each program in turn to use the memory
does not work with overlaying
'No preemption' condition for deadlock is defined as
A system is in the safe state if:
b)there exist a safe sequence
both a and b
a)the system can allocate resources to each process in some order and still avoid a deadlock
Virtual address is a
Virtual address is a page number and an offset within the page
Другого варианта нет)
Which of the following is not true about the memory management?
virtual memory is used only in multi-user systems
segmentation suffers from external fragmentation
paging suffers from internal fragmentation
segmented memory can be paged
None of the above
True or false: segmentation suffers from external fragmentation?
'Mutual exclusion' condition for deadlock is defined as
True or false: paging suffers from external fragmentation?
What is NOT an example of consumable resource?
Information in I\O buffers
Signals
Messages
What is a method of memory allocation by which the program is subdivided into equal portions, or pages and core is subdivided into equal portions or blocks?
virtual memory
partition
What is NOT an example of reusable resource?
interrupt
semaphores
processors
i/o channels
In memory systems, boundary registers?
track the beginning and ending of programs
track page boundaries
are only necessary with fixed partitions
are used for temporary program variable storage
On all instruction cycles, the processor accesses memory at least once, to: , and often one or more additional times, and/or .
Operating System maintains the page table for:
each process
each thread
each instruction
each address
A relationship between processes such that each has some part (critical section) which must not be executed while the critical section of another is being executed, is known as?
Multitasking
Semaphore
Mutual exclusion
In contiguous memory allocation:
each process is contained in a single contiguous section of memory
the memory space is contiguous
all processes is contained in a single contiguous section of memory
CPU fetches the instruction from memory according to the value of?
status register
program status word
When memory is divided into several fixed sized partitions, each partition may contain ________.
exactly one process
at least one process
multiple processes at once
The number of resources requested by a process:
must always be less than the total number of resources available in the system
must always be equal to the total number of resources available in the system
must not exceed the total number of resources available in the system
must exceed the total number of resources available in the system
A memory used to provide a high speed is called?
cache
main memory
disk buffer
stack pointer
In fixed sized partition, the degree of multiprogramming is bounded by ___________.
the memory size
the number of partitions
the CPU utilization
Which one of the following is the address generated by CPU?
logical address
physical address
absolute address
A deadlock avoidance algorithm dynamically examines the _____ to ensure that a circular wait condition can never exist
resource allocation state
operating system
resources
system storage state
The first fit, best fit and worst fit are strategies to select a ______.
process from a queue to put in memory
free hole from a set of available holes
processor to run the next process
Runtime mapping from virtual to physical address is done by?
CPU
memory management unit
PCI
In internal fragmentation, memory is internal to a partition and:
is not being used
is always used
is being used
Which of the following is not one of the principles of dealing with deadlock?
Initialization
Avoidance
Detection
Prevention
The address of a page table in memory is pointed by:
page table base register
page register
A solution to the problem of external fragmentation is:
larger memory size
unequal size parts
The Process Control Block is:
a secondary storage section
Process type variable
Data Structure
Block in memory
Program always deals with:
relative address
__________ is generally faster than _________ .
worst fit, best fit
best fit, first fit
first fit, best fit
Which one of the following is a synchronization tool?
socket
thread
pipe
semaphore
External fragmentation exists when:
the total memory is insufficient to satisfy a request
enough total memory exists to satisfy a request but it is not contiguous
a request cannot be satisfied even when the total memory is free
What is compaction?
a paging technique
a technique for overcoming fatal error
a technique for overcoming internal fragmentation
a technique for overcoming external fragmentation
What controls the process in a single-threaded process model?(не точно) из книги
User address space control block
User stack control block
Kernel stack control block
External fragmentation will not occur when:
no matter which algorithm is used, it will always occur
first fit is used
best fit is used
next fit is used
When the memory allocated to a process is slightly larger than the process, then:
both will occur
external fragmentation occurs
internal fragmentation occurs
In the non-blocking send:
the sending process keeps sending unit it receives a message
Main memory is broken into fixed-sized blocks called ________.:
pages
frames
segments
Fixed-length block of data in secondary memory is called ________.:
Variable-length block of data that resides in secondary memory is called ________.
The degree of multi-programming is:
the number of processes in memory
the number of processes executed per unit time
the number of processes in the ready queue
the number of processes in the I/O queue
Every address generated by the CPU is divided into two parts:
page number + page offset
Другого варианта нет
The __________ is used as an index into the page table.
page number
page offset
frame bit
frame offset
Trace of the process is: (из книги)
List of files that are opened
List of interactions of the process with other process
List of threads of the process
List of instructions that are executed
The _____ table contains the base address of each page in physical memory.
memory
page
frame
With paging there is no ________ fragmentation.
either type of
external
internal
A set of processes is deadlock if:
each process is blocked and will remain so forever
all processes are trying to kill each other
each process is terminated
The operating system maintains a ______ table that keeps track of how many frames have been allocated, how many are there, and how many are available.
segment
To find a free partition this algorithm starts searching from where it left off, not from the beginning (из книги)
Worst fit
Next fit
Best fit
First fit
For every process there is a __________.
pointer to page table
copy of page table
frame table
page table
If a page number is not found in the TLB, then it is known as a:
TLB miss
buffer miss
TLB ht
page fault
Mutual exclusion can be provided by the:
binary semaphores
both
mutex locks
If a page table entry is present in the TLB, then it is known as a:
TLB hit
If a page table entry is not in main memory, then it is known as a:
What is a medium-term scheduler?
It selects which process has to be executed next and allocates CPU
It selects which process has to be brought into the ready queue
It selects which process to remove from memory by swapping
In segmentation, each address is specified by (choose two):
a segment number
an offset
a value
a key
Which is the ready state of a process?
when process is using the CPU
when process is scheduled to run after some execution
when process is unable to run until some task has been completed
Which one of the following is the deadlock avoidance algorithm?
round-robin algorithm
elevator algorithm
banker’s algorithm
dinning philosophers problem