Deck 4: Processor Management

Question 1

When using a multiple-level queue strategy,aging is used to ensure that jobs in lower-level queues will eventually complete their execution.

Answer 1

True

Question 2

Context switching is required by all preemptive algorithms.

Answer 2

True

Question 3

In Round Robin scheduling,if processing isn't finished when time expires,the job is preempted and put at the end of the READY queue and its information is saved in its Process Control Block.

Answer 3

True

Question 4

Most computer programs alternate between CPU cycles and I/O cycles.

Question 5

First-come,first-served (FCFS)is a preemptive scheduling algorithm that handles jobs according to their arrival time.

Question 6

Web browsers use multithreading routinely.For example,one thread can retrieve images while another sends and retrieves e-mail.

Question 7

A job's state moves from HOLD to WAITING when it's ready to run but is waiting for the CPU.

Question 8

As a process moves through the system,its status changes.Possible process statuses include HOLD,READY,RUNNING,WAITING,and
FINISHED.

Question 9

It is possible to minimize response time by running only interactive jobs and letting batch jobs wait until the interactive load ceases.

Question 10

A single processor can be shared by several jobs,or several processes,but only if the operating system has a scheduling policy,as well as a scheduling algorithm,to determine when to stop working on one job and proceed to another.

Question 11

A processor is also known as a CPU.

Question 12

The control program that handles the interruption sequence of events is called the event scheduler.

Question 13

Shortest job next (SJN)is a nonpreemptive scheduling algorithm (also known as shortest job first,or SJF)that handles jobs based on the length of their CPU cycle time.

Question 14

When using priority scheduling,priorities are assigned to jobs by the owner of the job (the user).

Question 15

Dual core or quad core multi-core chips are larger than a single-processor chip but produce less current leakage and heat.

Question 16

The Processor Manager is a composite of at least two submanagers: one in charge of job scheduling and the other in charge of program scheduling.

Question 17

A program is an active entity that requires a set of resources,including a processor and special registers,to perform its function.

Question 18

CPU-bound jobs (such as printing a series of documents)have many brief CPU cycles and long I/O cycles.

Question 19

If one job monopolizes the system,the extent of its overall effect on system performance depends on the scheduling policy and whether the job is CPU-bound or I/O-bound.

Question 20

The shortest remaining time (SRT)algorithm is often used in interactive systems.

Question 21

The transition from ____ can be initiated by the Process Scheduler or the Job Scheduler.

A) WAITING to READY
B) RUNNING to WAITING
C) RUNNING to FINISHED
D) HOLD to READY

Question 22

A(n)____ is created by a process,and it can be scheduled and executed independently of its parent process.

A) thread
B) program
C) miniprocess
D) instruction set

Question 23

The Process Scheduler assigns the CPU to execute the processes for those jobs placed on the ____ queue by the Job Scheduler.

A) WAITING
B) NEXT
C) PROCESS
D) READY

Question 24

An I/O request is called a(n)____ wait in multiprogramming environments.

A) forced
B) natural
C) scheduled
D) indirect

Question 25

____ allows for faster turnaround of CPU-bound jobs.

A) No movement between queues
B) Movement between queues
C) Variable time quantum per queue
D) Aging

Question 26

Assume that four jobs,A-D,require the CPU cycles listed below.Using the SJN algorithm,the average turnaround time is ____. Job: A B C D
CPU cycle: 5 2 6 4

A) 5.5
B) 6.8
C) 9.0
D) 11.1

Question 27

When a job is accepted by the system,it's put on ____ and placed in a queue.

A) HOLD
B) RUNNING
C) WAITING
D) READY

Question 28

Each thread in a process is represented by a data structure called a ____ that contains basic information such as the thread's unique identification,state,and priority.

A) Thread Control Block
B) Thread State Block
C) Thread Pointer
D) Thread Queue

Question 29

____ requires that the processor be allocated to each job or to each process for a period of time and deallocated at an appropriate moment.

A) Cyclic programming
B) Dedicated processing
C) Multiprogramming
D) Multi-core processing

Question 30

No movement between queues is a very simple policy that rewards those who have ____ jobs.

A) high-priority
B) low-priority
C) CPU-bound
D) I/O-bound

Question 31

The Job Scheduler seeks to ____ when scheduling jobs.

A) run all CPU intensive jobs first
B) run all I/O intensive jobs first
C) balance CPU and I/O intensive jobs
D) run the quickest jobs first

Question 32

Assume that jobs A-D arrive in the READY queue in quick succession and have the CPU cycle requirements listed below.Using the SRT algorithm,the average turnaround time is ____. Arrival time: 0 1 2 3
Job: A B C D
CPU cycle: 6 3 1 4

A) 2.5
B) 6.25
C) 7.75
D) 9.0

Question 33

When the operating system detects a nonrecoverable error,the following step is performed first by the interrupt handler: ____.

A) the state of the interrupted process is saved
B) the type of interrupt is described and stored
C) the interrupt is processed
D) the processor resumes operation

Question 34

Assume that four jobs,A-D,are in the READY queue at Time 0 and require the CPU cycles listed below.Using the SJN algorithm,the ____ job is run first. Job: A B C D
CPU cycle: 5 2 6 4

A) A
B) B
C) C
D) D

Question 35

The ____ is also called a high-level scheduler.

A) Process Scheduler
B) Job Scheduler
C) Program Scheduler
D) Thread Scheduler

Question 36

____ is a dynamic-priority preemptive scheduling algorithm built to address the critical processing requirements of real-time systems and their pressing deadlines.

A) Variable Time Quantum Per Queue
B) Round Robin
C) Shortest Job Next
D) Earliest Deadline First

Question 37

A general rule of thumb for selecting a proper time quantum in Round Robin scheduling is that it should be long enough to allow ____ percent of the CPU cycles to run to completion.

A) 20
B) 60
C) 80
D) 100

Question 38

The first-come,first-served (FCFS)algorithm is fine for most ____ systems.

A) multiuser
B) user initiated
C) interactive
D) batch

Question 39

Some systems use a strategy known as ____ to increase the priority of jobs that have been in the system for an unusually long time in order to expedite their exit.

A) lagging
B) aging
C) bumping
D) accelerated priority

Question 40

The transition from ____ is initiated by the Job Scheduler according to some predefined policy.At this point,the availability of enough main memory and any requested devices is checked.

A) READY to RUNNING
B) RUNNING to WAITING
C) RUNNING back to READY
D) HOLD to READY