Deck 6: Real-Time Operating System Scheduling and Job Management

Question 1

Tasks whose execution would begin randomly and within the interval of arrival times of consecutive tasks is known as

A)Periodic Task
B)Aperiodic Task
C)Sporadic Task
D)none of the mentioned

Answer 1

Sporadic Task

Question 2

What is True for a task vis-à-vis a process?

A)Tasks are complex compared to processes
B)Tasks represent only a single sequence of instructions
C)Processes can spawn threads but tasks cannot spawn tasks Tasks and processes are one and the same thing
D)Tasks and processes are one and the same thing

Answer 2

Tasks represent only a single sequence of instructions

Question 3

What does the utilization rate tells us? Select one:

A)If it is larger or equal to 1, the system is not feasible
B)If it is smaller than 1, the system is feasible
C)If it is exactly 1, the system is feasible
D)if there is no context switch overhead If it is 0, the system is absolutely feasible

Answer 3

If it is larger or equal to 1, the system is not feasible

Question 4

if jobs have unpredictable release times, a task is termed :

A)aperiodic
B)sporadic periodic.
C)both A &B
D)None of these

Question 5

What is TRUE for an aperiodic task and a sporadic task:

A)A sporadic task and an aperiodic task are one and the same thing
B)An aperiodic task occurs randomly and has hard real time requirements
C)A sporadic task occurs randomly and has hard real time requirements
D)A sporadic task becomes aperiodic when it is executed with a periodic task

Question 6

State whether the following statements are True or False for the features of real time operating system.
i. fast process or thread switch
ii. ability to respond to external interrupts quickly.
iii. minimization of intervals during which interrupts are enabled.
iv. preemptive scheduling based on priority

A)i, ii and iii only
B)ii, iii and iv only
C)i, ii and iv only
D)All i, ii, iii and iv

Question 7

Effective release time of a job without the predecessors is equal to its given …………….

A)release time
B)Deadline
C)both A &B
D)None of these

Question 8

Effective release time of a job with predecessors is equal to the maximum value among, its…………and…………..

A)deadline time and effective release time of all of the predecessors.
B)release time and effective release time of all of the predecessors.
C)both A &B
D)None of these

Question 9

Effective deadline of job without the successor is equal to its given ……………

A)release time
B)Deadline
C)both A &B
D)None of these

Question 10

Effective deadline of job with successor is equal tothe minimum value among its deadlines and …………………………

A)only deadline of job
B)Release time of all the successors
C)deadlines of all the successors
D)None of these

Question 11

LRT schedules all the job backward from …………………... of all the job in priority driven manner to the current time.

A)Earliest deadline
B)latest deadline
C)latest releasetime
D)None of these

Question 12

In on-line scheduling, scheduler make the schedule ……………………... that will be released in future.

A)with the knowledge of the jobs
B)without the knowledge of the jobs
C)both A &B
D)None of these

Question 13

In which scheduling certain amount of CPU time is allocated to each process ?

A)earliest deadline first scheduling
B)roportional share scheduling
C)equal share scheduling
D)none of the mentioned

Question 14

Scheduling of tasks is a very important consideration in RTOS. Which of the following best described the scheduling policy design:

A)The scheduler must follow a pre-emptive policy
B)The scheduler must not use pre-emptive policy option
C)The scheduler must not only use pre-emptive policy options with the priority considerations.
D)The scheduler must not use pre-emptive policy option, but must employ priority consideration.