Project-1 design issues
- Once the process
becomes long, it stays long
- The job id does not indicate the arrival time
- All the resources are pre-allocated. A process keeps these resources from the time when it enters till it completes execution
- Short jobs and long jobs can’t be in the ready queue at the same time.
- If a display arrives and the quantum is NOT interrupted, and an arrival comes in before the quantum, then the display is forgotten.
Important Issues
1. If job X is running but is long (in other words the ready queue is empty) and
job Y arrives and moves to the ready queue, job X goes to the
end of the ready queue and
causes the long queue to go back to long.
2. If job X arrives and CAN start, then it goes to the ready queue but does NOT
interrupt the currently executing job. (unless it is long).
3. On your design, picture you writing the job scheduler and someone else writing the process scheduler, I should not be able to change the
amount
of MM for that job.