Chapter 5 Scheduling Flashcards Preview

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Flashcards in Chapter 5 Scheduling Deck (14)
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1
Q

What is one possible goal of the RR policy?

A

Equal distribution of CPU.

2
Q

List one advantage and one disadvantage of FCFS.

A

Advantage: Easy to implement, all services get executed;

Disadvantage: Not a fast method, ignores service time and isn’t a great performer.

3
Q

Define the two kinds of processor affinity.

A

Soft: Migrate between process.

Hard: Run one process at a time.

4
Q

What are the two ways load balancing can be achieved?

A

Push migration

Pull migration

5
Q

What is the wait time of a process?

A

The sum of the periods spent waiting in the ready queue.

6
Q

What is the turnaround time of a process?

A

The sum of the periods spent waiting to get into memory, waiting in the ready queue, executing on the CPU, and doing I/O.

7
Q

What is the response time of a process?

A

The time it takes to start responding, not the time it takes to output the response.

8
Q

Give an advantage and disadvantage of the shortest job next algorithm.

A

Advantage: Minimizes wait time.

Disadvantage: May starve large jobs, difficulty determining service times.

9
Q

Give an advantage and disadvantage of the deadline scheduling algorithm.

A

Advantage: Allocates service by deadline.

Disadvantage: May not be feasible.

10
Q

Explain the impact of quantum size

A

Too Large:
Processes complete but all other processes have a long wait.

Too Small:
May increase the number of ready processes.

11
Q

Give an advantage and disadvantage of the Round Robin algorithm.

A

Advantages: Equitable
Most widely-used
Fits naturally with interval timer

Disadvantages: overhead

12
Q

Give an advantage and disadvantage of the Priority scheduling algorithm.

A

Advantages: Reflects importances of external use, can address starvation with aging.

Disadvantages: May cause starvation

13
Q

Define the two types of real time scheduling.

A

Hard real-time systems – required to complete a critical task within a guaranteed amount of time.

Soft real-time computing – requires that critical processes receive priority over less fortunate ones.

14
Q

Define the two types of priority schemes.

A

Static: priority set up and does not change.

Dynamic: priority can change over time.