Process Burst Time Arrival Time Priority P1 5 0 1 P2 1 0 3 P3 2 2 1 P4 4 4 2 P5 2 4 2 P6 3 5 3 P7 4 5 3
Hi guys. We're given an assignment about Preemptive Priority Scheduling and I really don't know how to do this given two or more processes having the same priority number.
I have to make a gantt chart, compute turn-around time, and average waiting time.
If possible, can you guys post a step-by-step solution on how to do it so that I can study how it's done.
Thanks for the help guys.
Best Answer
Firstly: two processes with the same priority will generally be sorted according to their arrival time: so first come first serve.
Turn around time: generally refers to the amount of time required for the process to produce output. Your course may use a different or simpler definition to make your calculations easier. From what I can see you are probably being asked to compute the amount of time it takes for each process to complete. This is equal to:
finish_time - time_first_scheduled_on_CPU
(notfinish_time - arrival_time
).Average waiting time: Based on the Gantt chart you develop which shows exactly when and for how long a process is on the CPU, you can compute the total amount of time each process was waiting to get on the CPU.
This consists of: