Lesson 5 - Interrupts

Question 1

What is an interrupt?

Answer 1

It is a signla generated that tells the processor to stop what it’s currntly doing and give its attnetion to another process.

Question 2

What is a hardware interrupt?

Answer 2

-Getting new inputs form a keyboard, or mouse, or connecting devices

Question 3

What are priorty levels?

Answer 3

• How urgents the interrupts nee to be addressed.
• Similar to a queue.
• Interrupts are storeed in a data structure called a priority queue.
• Soted in the interrupt register.

Question 4

When the does the processor check for interrupts?

Answer 4

-It checks for interrupts at the end of te fetch devocde execute cycle.

Question 5

What does ISR stand for?

Answer 5

-Stands for Interrupt service rountine.

Question 6

What is a job in the procesor?

Answer 6

-A process that is runing right now.

Question 7

What is pre-emptive sheduling?

Answer 7

-Jobs can be started and stopped by the operating system

Question 8

What is non pre-emptive sheduling?

Answer 8

-Once the job as started it can finish

Question 9

What is the round robin sheduling routine?

Answer 9

• Each job is given a cetian amount of processor time. In which it can be executed.
• It is pre-emptive.

Question 10

What are the advantages of RR?

Answer 10

-It insures that each process gets the same amount of processor time.

Question 11

What are the disadvantages of Round Robin?

Answer 11

-Long jobs take alot longer to complete.

Question 12

What are Multi-level feedback queues?

Answer 12

It uses multiple queues isntead of single queues- Almost like a vip folder.
- It is non pre-emptive.

Question 13

What are the advantages of MLFQ?

Answer 13

• Each queue has a different level of priority.
• Each queue is ordered by priority.
• High priority jobs cna be executed first.

Question 14

What are the disadvantages of MLFQ?

Answer 14

• it is difficult to impleemnt because deciding how to order tasks is difficult.