Lesson 5 - Interrupts Flashcards
What is an interrupt?
It is a signla generated that tells the processor to stop what it’s currntly doing and give its attnetion to another process.
What is a hardware interrupt?
-Getting new inputs form a keyboard, or mouse, or connecting devices
What are priorty levels?
- 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.
When the does the processor check for interrupts?
-It checks for interrupts at the end of te fetch devocde execute cycle.
What does ISR stand for?
-Stands for Interrupt service rountine.
What is a job in the procesor?
-A process that is runing right now.
What is pre-emptive sheduling?
-Jobs can be started and stopped by the operating system
What is non pre-emptive sheduling?
-Once the job as started it can finish
What is the round robin sheduling routine?
- Each job is given a cetian amount of processor time. In which it can be executed.
- It is pre-emptive.
What are the advantages of RR?
-It insures that each process gets the same amount of processor time.
What are the disadvantages of Round Robin?
-Long jobs take alot longer to complete.
What are Multi-level feedback queues?
It uses multiple queues isntead of single queues- Almost like a vip folder.
- It is non pre-emptive.
What are the advantages of MLFQ?
- Each queue has a different level of priority.
- Each queue is ordered by priority.
- High priority jobs cna be executed first.
What are the disadvantages of MLFQ?
- it is difficult to impleemnt because deciding how to order tasks is difficult.
