Deck 8: Understanding Processor Scheduling and Memory Management in Operating Systems

Question 1

Which of the following is not a performance criterion that a processor scheduler should attempt to satisfy.

A) throughput
B) latency
C) maximizing processor utilization
D) none of the above

Answer 1

none of the above

Question 2

The intermediate-level scheduler determines ___________.

A) which jobs may gain admission to the system and actively compete for system resources
B) which jobs may actively compete for processors
C) which active process the system will assign to a processor when one next becomes available
D) none of the above

Answer 2

which jobs may actively compete for processors

Question 3

At a minimum, an operating system typically implements __________.

A) a high-level scheduler
B) a high-level and a low-level scheduler
C) an intermediate-level and a low-level scheduler
D) a high-level, intermediate-level and low-level scheduler

Answer 3

an intermediate-level and a low-level scheduler

Question 4

The ________ dispatches a processor to the process chosen to execute next.

A) high-level scheduler
B) intermediate-level scheduler
C) low-level scheduler
D) both b and c

Question 5

Under ________ scheduling, processes can be interrupted whether they have completed their current task or not.

A) dynamic
B) nonpreemptive
C) static
D) preemptive

Question 6

A disadvantage of preemptive scheduling is ________.

A) increased overhead
B) the possibility that a process can monopolize the system while executing an infinite loop
C) that short processes can experience lengthy service delays while longer processes complete
D) both a and b

Question 7

A ________ priority system incurs less overhead than a ________ priority system but is less responsive to changing conditions in the system.

A) dynamic, static
B) static, dynamic
C) preemptive, nonpreemptive
D) nonpreemptive, preemptive

Question 8

When a user purchases priority, that user's process ______.

A) gets immediate access to resources
B) can preempt any resource from another process
C) gets a higher level of service than processes that have not purchased priority
D) none of the above

Question 9

________ is not generally considered one of the most important objectives in scheduler design.

A) Avoiding indefinite postponement
B) Minimizing overhead
C) Enforcing priorities
D) Maximizing throughput

Question 10

A scheduling discipline is said to be ________if all similar processes are treated the same, and no process can suffer indefinite postponement due to scheduling issues.

A) predictable
B) scalable
C) portable
D) fair

Question 11

________ occurs when a low-priority process temporarily is assigned higher priority than a high-priority process.

A) Indefinite postponement
B) Priority inversion
C) Batch processing
D) Deadlock

Question 12

A(n) ________ process tends to use all the processor time that the system allocates for it.

A) processor-bound
B) I/O-bound
C) batch
D) interactive

Question 13

A system should provide good response times to a(n) ________ process, whereas a(n) ________ process generally can withstand reasonable delays.

A) processor-bound, I/O-bound
B) I/O-bound, processor-bound
C) batch, interactive
D) interactive, batch

Question 14

Under ________ scheduling, processes execute in the order the scheduler receives them.

A) SRT
B) HRRN
C) RR
D) FIFO

Question 15

FIFO scheduling ________.

A) preempts processes after they have executed beyond the maximum timeout value
B) is most appropriate for scheduling interactive processes
C) is fair in that it schedules processes according to their arrival times
D) is fair in that important processes get preference over unimportant processes

Question 16

When the quantum size is too ________, the overhead involved in ________ dominates and performance degrades.

A) large, context-switching
B) small, context-switching
C) large, adjusting priorities
D) small, adjusting priorities

Question 17

The use of aging in a round-robin scheme helps to ________.

A) enforce mutual exclusion
B) reduce the overhead of context-switching
C) prevent deadlock
D) prevent indefinite postponement

Question 18

Under SPF scheduling, important processes will be executed ________.

A) according to their estimated time to completion
B) before less important processes can execute
C) after less important processes have completed execution
D) in a random order to ensure fairness

Question 19

SPF scheduling might be desirable when ________ is the primary goal of the system.

A) fairness
B) high throughput
C) good interactivity
D) minimum overhead

Question 20

HRRN is a(n) ________ scheduling discipline in which each process's priority is a function of its ________.

A) preemptive, service time
B) preemptive, service time and time spent waiting for service
C) nonpreemptive, service time
D) nonpreemptive, service time and time spent waiting for service

Question 21

Incorporating ________ when assigning priorities allows HRRN to avoid indefinite postponement, similar to aging in RR schemes.

A) wait time
B) variance of response times
C) service time
D) throughput

Question 22

SRT scheduling essentially incorporates ________ into SPF scheduling.

A) HRRN
B) preemption
C) aging
D) batch processing

Question 23

________ contributes to a larger overhead in SRT than SPF.

A) Accounting for potential user abuse
B) Estimating future process behavior
C) Performing preemptions
D) both a and b

Question 24

In general, multilevel feedback queues push ________ processes to lower-level queues and ________ processes to higher-level queues, resulting in rapid response times to interactive requests.

A) low-priority, high-priority
B) I/O-bound, processor-bound
C) processor-bound, I/O-bound
D) both a and c

Question 25

Multilevel feedback queuing ________.

A) is an example of an adaptive mechanism
B) is most appropriate for real-time systems
C) incurs too much overhead to be practical in real systems
D) both a and c

Question 26

Fair share scheduling ensures ________.

A) fairness across sets of processes grouped by individual user
B) fairness across sets of unrelated processes
C) that the performance of a process is affected only by the population of its process group
D) both a and c

Question 27

Deadline scheduling is most important in ________ systems.

A) batch-processing
B) real-time
C) interactive
D) single-user

Question 28

The intense resource management that deadline scheduling requires often leads to increased ________ in those systems.

A) overhead
B) throughput
C) latency
D) both a and b

Question 29

Soft real-time scheduling ________.

A) ensures that real-time processes are dispatched before other processes in the system
B) guarantees that real-time processes meet their timing constraints
C) benefits from low interrupting clock rates
D) all of the above

Question 30

________ scheduling algorithms guarantee that a process's timing constraints are always met.

A) Preemptive
B) Nonpreemptive
C) Soft real-time
D) Hard real-time

Question 31

The ________ algorithm bases priority on the amount of time until a process's deadline and the remaining execution time until its task has completed.

A) rate-monotonic
B) deadline rate-monotonic
C) earliest-deadline-first
D) minimum-laxity-first

Question 32

In an operating system that supports threads, processor scheduling can be performed by ________.

A) the operating system, by dispatching processes
B) the operating system, by dispatching threads
C) user-level libraries, by dispatching threads
D) all of the above

Question 33

If there are multiple threads at the highest priority level in the Java virtual machine, those threads execute using a(n) ________ scheduling algorithm.

A) FIFO
B) round-robin
C) SPF
D) SRT

Question 34

On a system that does not support timeslicing, Java threads will run to completion in order unless they voluntarily relinquish control by calling the ________ method.

A) yield
B) suspend
C) sleep
D) halt