CPU Non-Preemptive Scheduling

CPU Non-Preemptive Scheduling

1. CPU Non-Preemptive Scheduling

2. Member Mahmudullah 151-15-5073 M . Munem Mostaqem 151-15-4873 Md . Fardin Hassan 152-15-5532 Mehedi Hasan Ratul 152-15-5711 Md Jahid Hasan 152-15-5787 Mohammad Shakhawat Hossain 151-15-4727

3. Definition Preemptive Scheduling. - SRTF, Priority, Round Robin, etc . Non- preemptive Scheduling. - FCFS,  SJF, Priority, etc.

4. FCFS Process:  Non- preemptive scheduling algorithm. Follow first in first out (FIFO) method.

5. FCFS Example 1: (Without Arrival time)

6. FCFS Total Wait Time= Average Waiting Time = Total Turn Around Time= Average Turn Around time =

7. FCFS Example 2: ( with Arrival Time)

8. FCFS Total Wait Time= Average Waiting Time = Total Turn Around Time= Average Turn Around time =

9. SJF   Process: once CPU given to the process it cannot be preempted until completes its CPU burst Ready queue is treated as a priority queue based on smallest CPU time requirement.

10. SJF Example 1: ( Without arrival time)

11. SJF Total Wait Time 6 + 0 + 3 = 9 ms Average Waiting Time = (Total Wait Time) / (Total number of processes) 9/3 = 3 ms Total Turn Around Time 30 + 3 + 6 = 39 ms Average Turn Around time = (Total Turn Around Time) / (Total number of processes) 39 / 3 = 13 ms

12. SJF Example 2: (With Arrival Time)

13. SJF Total Wait Time= 0 + 7 + 15 + 9 = 31 ms Average Waiting Time = 31/4 = 7.75 ms Total Turn Around Time = 8+11+ 14+24= 57 Average Turn Around time = 57/4 = 14.25 ms

14. Priority Process: Each process is assigned a priority. Process with highest priority is to be executed first and so on. Processes with same priority are executed on first come first served basis.

15. Priority Example: (With Arrival time) Gantt chart

16. Priority Average Wait Time : (9+5+12+0) / 4 = 6.5

17. Priority Gantt chart: Example 2: (without Arrival time)

18. Priority

19. Question?

20. THANK YOU!