A process is selected from the ______ queue by the ________ scheduler, to be executed.
1.blocked, short term
2.wait, long term
3. ready, short term
4.ready, long term
Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section ____
1.after a process has made a request to enter its critical section and before the request is granted
2.when another process is in its critical section
3. before a process has made a request to enter its critical section
4.None of the mentioned
Semaphore is a/an _______ to solve the critical section problem.
1. hardware for a system
2. special program for a system
3.integer variable
4. none of the mentioned
What are the two atomic operations permissible on semaphores?
1.wait
2.stop
3.hold
4. none of the mentioned
Which is the most optimal scheduling algorithm?
1.FCFS – First come First served
2.SJF – Shortest Job First
3.RR – Round Robin
4.None of the mentioned
Which of the following conditions must be satisfied to solve the critical section problem?
1. Mutual Exclusion
2. Progress
3.Bounded Waiting
4.All of the Mentioned
A binary semaphore is a semaphore with integer values _____
1. 1
2.-1
3. 0.8
4.0.5
A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem.
1. one
2. two
3.three
4. four
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 ________
1.data consistency
2.race condition
3.aging
4.starvation
A solution to the problem of indefinite blockage of low – priority processes is _____
1.Starvation
2.Wait queue
3.Ready queue
4.Aging
An I/O bound program will typically have _____
1.a few very short CPU bursts
2. many very short I/O bursts
3.many very short CPU bursts
4.a few very short I/O bursts
An SJF algorithm is simply a priority algorithm where the priority is ______
1. the predicted next CPU burst
2. the inverse of the predicted next CPU burst
3.the current CPU burst
4.anything the user wants
An un-interruptible unit is known as ______
1. single
2.atomic
3. static
4. none of the mentioned
At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore. The resulting value of the semaphore is? (GATE 1987)
1.42
2.2
3.7
4.12
Choose one of the disadvantages of the priority scheduling algorithm?
1.it schedules in a very complex manner
2.its scheduling takes up a lot of time
3. it can lead to some low priority process waiting indefinitely for the CPU
4.None of the mentioned
Concurrent access to shared data may result in ________
1. data consistency
2.data insecurity
3.data inconsistency
4.None of the mentioned
CPU scheduling is the basis of ______
1.multiprocessor systems
2.multiprogramming operating systems
3. larger memory sized systems
4.None of the mentioned
If the semaphore value is negative ____
1. its magnitude is the number of processes waiting on that semaphore
2.it is invalid
3.no operation can be further performed on it until the signal operation is performed on it
4.None of the mentioned
In the bakery algorithm to solve the critical section problem ______
1. each process is put into a queue and picked up in an ordered manner
2.each process receives a number (may or may not be unique) and the one with the lowest number is served next
3. each process gets a unique number and the one with the highest number is served next
4.each process gets a unique number and the one with the lowest number is served next
In the following cases non – preemptive scheduling occurs?
1.When a process switches from the running state to the ready state
2.When a process goes from the running state to the waiting state
3.When a process switches from the waiting state to the ready state
4.All of the Mentioned
Mutual exclusion implies that _______
1.if a process is executing in its critical section, then no other process must be executing in their critical sections
2.if a process is executing in its critical section, then other processes must be executing in their critical sections
3.if a process is executing in its critical section, then all the resources of the system must be blocked until it finishes execution
4.None of the mentioned
Orders are processed in the sequence they arrive if _______ rule sequences the jobs.
1.earliest due date
2. slack time remaining
3. first come, first served
4.critical ratio
Preemptive Shortest Job First scheduling is sometimes called ______
1. Fast SJF scheduling
2.EDF scheduling – Earliest Deadline First
3.HRRN scheduling – Highest Response Ratio Next
4.SRTN scheduling – Shortest Remaining Time Next
Scheduling is done so as to _______
1.increase CPU utilization
2.decrease CPU utilization
3.keep the CPU more idle
4.None of the mentioned
Semaphores are mostly used to implement _______
1.System calls
2.IPC mechanisms
3. System protection
4.None of the mentioned
TestAndSet instruction is executed ______
1.after a particular process
2.periodically
3. atomically
4.None of the mentioned
The code that changes the value of the semaphore is ________
1. remainder section code
2.non – critical section code
3.critical section code
4.None of the mentioned
The real difficulty with SJF in short term scheduling is _____
1.it is too good an algorithm
2.knowing the length of the next CPU request
3.it is too complex to understand
4.None of the mentioned
The segment of code in which the process may change common variables, update tables, write into files is known as _____
1. program
2.critical section
3.non – critical section
4. synchronizing
The signal operation of the semaphore basically works on the basic _______ system call.
1.continue()
2.wakeup()
3. getup()
4.start()
The strategy of making processes that are logically runnable to be temporarily suspended is called _____
1.Non preemptive scheduling
2.Preemptive scheduling
3. Shortest job first
4. First come First served
The switching of the CPU from one process or thread to another is called _____
1. process switch
2.task switch
3. context switch
4.All of the Mentioned
The wait operation of the semaphore basically works on the basic _______ system call.
1.stop()
2.block()
3.hold()
4.wait()
There are 10 different processes running on a workstation. Idle processes are waiting for an input event in the input queue. Busy processes are scheduled with the Round-Robin time sharing method. Which out of the following quantum times is the best value for small response times, if the processes have a short runtime, e.g. less than 10ms?
1.tQ = 15ms
2.tQ = 40ms
3. tQ = 45ms
4. tQ = 50ms
Under multiprogramming, turnaround time for short jobs is usually ________ and that for long jobs is slightly _____
1.Lengthened; Shortened
2.Shortened; Lengthened
3. Shortened; Shortened
4.Shortened; Unchanged
What are Spinlocks?
1.CPU cycles wasting locks over critical sections of programs
2.Locks that avoid time wastage in context switches
3.Locks that work better on multiprocessor systems
4. All of the mentioned
What are the two kinds of semaphores?
1.mutex & counting
2.binary & counting
3.counting & decimal
4.decimal & binary
What are the two steps of a process execution?
1. I/O & OS Burst
2. CPU & I/O Burst
3.Memory & I/O Burst
4.OS & Memory Burst
What is a mutex?
1. is a binary mutex
2.must be accessed from only one process
3.can be accessed from multiple processes
4.None of the mentioned
What is a semaphore?
1.is a binary mutex
2.must be accessed from only one process
3.can be accessed from multiple processes
4. none of the mentioned
What is ‘Aging’?
1.keeping track of cache contents
2. keeping track of what pages are currently residing in memory
3.keeping track of how many times a given page is referenced
4. increasing the priority of jobs to ensure termination in a finite time
What is Response time?
1.the total time taken from the submission time till the completion time
2. the total time taken from the submission time till the first response is produced
3. the total time taken from submission time till the response is output
4.ValidationSummary
What is Scheduling?
1.allowing a job to use the processor
2.making proper use of processor
3.all of the mentioned
4.None of the mentioned
What is the main disadvantage of spinlocks?
1.they are not sufficient for many process
2.they require busy waiting
3.they are unreliable sometimes
4.they are too complex for programmers
What is Turnaround time?
1.the total waiting time for a process to finish execution
2.the total time spent in the ready queue
3. the total time spent in the running queue
4.the total time from the completion till the submission of a process
What is Waiting time?
1.the total time in the blocked and waiting queues
2.the total time spent in the ready queue
3. the total time spent in the running queue
4.the total time from the completion till the submission of a process
What will happen if a non-recursive mutex is locked more than once?
1. Starvation
2.Deadlock
3.Aging
4.Signaling
Which of the following algorithms tends to minimize the process flow time?
1.First come First served
2. Shortest Job First
3. Earliest Deadline First
4. Longest Job First
Which of the following scheduling algorithms gives minimum average waiting time?
1.FCFS
2.SJF
3.Round – robin
4.Priority
With multiprogramming ______ is used productively.
1.time
2.space
3.money
4.All of the Mentioned