Hệ Điều Hành - operating system Học viện PTIT

hdh ptit

1. Ôn tập HĐH ngày
30/11/2022
SUS Imposter Detected

2. Các thuật toán điều độtiến trình

3. FCFS: First Come, First Served

4. FCFS: First Come, First Served
ProcessBurst Time
P15
P23
P31
P47
P54

5. FCFS: First Come, First Served
ProcessBurst Time
P15
P23
P31
P47
P54
0589 16
5317 4
P1P2P3P4 P5
058916
7.6
5
t
++++
==

6. RR: round robin

7. RR: round robin
ProcessBurst Time
(Quantum = 2)
P15
P23
P31
P47
P54

8. RR: round robin
ProcessBurst Time
(Quantum = 2)
P15
P23
P31
P47
P54
0246810121416182022
222222222222
P1P2P3P4P5P1P2P4P5P1P4P4
•P1: 0 + (10 -2) + (18 -12) = 14
•P2: 2 + (12 –4) = 10
•P3: 4
•P4: 6 + (14 –8) + (20 –16) = 16
•P5: 8 + (16 –10) = 14
141041614
11,6
5
t
++++
==

9. SPF: Shortest Job First

10. SJF: Shortest Job First
ProcessBurst Time
P15
P23
P31
P47
P54

11. SJF: Shortest Job First
ProcessBurst Time
P15
P23
P31
P47
P54
014813
13457
P3P2P5P1P4
014813
5,2
5
t
++++
==

12. SRTF: Shortest Remaining Time First

13. SRTF: Shortest Remaining Time First
ProcessBurstArrival
P1150
P2200
P32020
P42025
P55 45
P61555

14. SRTF: Shortest Remaining Time First
Proc
ess
Bur
st
Arrival
P1150
P2200
P32020
P42025
P5545
P61555
0153545506075
P1P2P3P5P3P6P4
1520105101520
At SecondEventDecision
0P1 and P2 arrivalP1 go to CPU
(P1<P2)
15P1 doneP2 go to CPU
20P3 ArrivalP2: Remain 15s
P3: 20s
P2 continue
25P4 ArrivalP2: Remain 10s
P3: 20s
P4: 25s
P2 continue
35P2 doneP3: 20s
P4: 20s
P3 go to CPU

15. SRTF: Shortest Remaining Time First
Proc
ess
Bur
st
Arrival
P1150
P2200
P32020
P42025
P5545
P61555
0153545506075
P1P2P3P5P3P6P4
1520105101520
At SecondEventDecision
35P2 doneP3: 20s
P4: 20s
P3 go to CPU
45P5 arrivalP3: 10s
P4: 20s
P5: 5s
P3 out
P5 go to CPU
50P5 doneP3: 10s
P4: 20s
P3 back to CPU
55P6 arrivalP3: 5s
P4: 20s
P6: 15s
P3 continue

16. SRTF: Shortest Remaining Time First
Proc
ess
Bur
st
Arrival
P1150
P2200
P32020
P42025
P5545
P61555
0153545506075
P1P2P3P5P3P6P4
1520105101520
At SecondEventDecision
55P6 arrivalP3: 5s
P4: 20s
P6: 15s
P3 continue
60P3 doneP4: 20s
P6: 15s
P6 go to CPU
75P6 doneP4 go to CPU
95P4 doneTHE END

17. SRTF: Shortest Remaining Time First
ProcessBurstArrivalWait Time
P11500
P220015
P32020(35-20) + (50-45) = 20
P42025(75-25) = 55
P55450
P61555(60-55) = 5
0153545506075
P1P2P3P5P3P6P4
1520105101520
015205505
15,83
6
t
+++++
==

18. SRTF: Shortest Remaining Time First

19. SRTF: Shortest Remaining Time First
3 10
P1 P2
7
At SecondEventDecision
3P1 arrivalP1 go to CPU
10P2 arrivalP1: Remain 30
P2: 20
P1 out
P2 go to CPU
24P3 ArrivalP1: Remain 30
P2: 6
P3: 14
P2 continue

20. SRTF: Shortest Remaining Time First
3103044
P1P2P3P1
7201430
At SecondEventDecision
24P3 ArrivalP1: Remain 30
P2: 6
P3: 14
P2 continue
30P2 doneP1: Remain 30
P3: 14
P3 go to CPU
44P3 DoneP1 go to CPU

21. SRTF: Shortest Remaining Time First
3103044
P1P2P3P1
7201430
ProccessWait Time
P1(3-3) + (44 –10) = 34
P20
P330 –24 = 6
3406
13,3
3
t
++
==

22. Priority Scheduling

23. Priority Scheduling
uSốlượng ưu tiên lớn hơn nghĩa là mức độưu tiên cao hơn
ProcessBurst TimePriority Simp
P154
P231
P312
P472
P543

24. Priority Scheduling
uSốlượng ưu tiên lớn hơn nghĩa là mức độưu tiên cao hơn
ProcessBurst TimePriority Simp
P154
P231
P312
P472
P543
05910 17
5417 3
P1P5P3P4 P2
0591017
8,2
5
t
++++
==

25. Priority Scheduling

26. Priority Scheduling
0 101518
10 538
P1 P3P4P2
T= [(0-0) + (10-4) + (15 –5) + (18 –2)]/4 = 8

27. Priority Scheduling