I am currently studying for an exam which includes operating systems. I solve exams from previous years and I am stuck on a particular question:
"One of the advantages of preemptive planning is:"
1.Promotes I / O related processes
2. performs more processes in a specified period of time
3.Promotes processor-related processes
4. None of the above
From what I have learned, I assume that if a particular scheduler promotes I / O or CPU related processes is the scheduler itself (and also whether it is preemptive or not ), so I don't think it's 1 or 3.
Option 2 makes sense, since if you interrupt processes to run other processes, more are executed in less time.
But it could also happen that, giving the example of a preemptive priority scheduling, if I have two processes, P1 and P2. P1 has the highest priority and P2 the lowest. P1 arrives at time 0 and P2 arrives at time 2 and P1 has an execution time of 5 units.
It makes no difference whether the algortihm is preemptive or not in this case for the time it takes to execute both processes.
In addition, Round Robin promotes processor-related processes. Should I assume that because Round Robin favors the processor, all preemptives also favor the processor?
What is the correct answer and why?