نظم تشغيل عملي

Cpu Scheduling methods
CPU scheduling
( Short Term Scheduling )
1- First Come First Server
2- Shortest Job First
A- non preemptive
B- preemptive
3- Priority
A- Non preemptive
B- preemptive
4- Round Robin
First Come First Server (FCFS)this method depended on process arrival time to ready Queue .

Average waiting time is generally not minimal
FCFS is non-preemptive
Not good for time sharing systems where each user needs to get a share of the CPU at regular intervals
Algorithm : non preemptive
First Come First Server (FCFS)this method depended on process arrival time to ready Queue .

Average waiting time is generally not minimal
FCFS is non-preemptive
Not good for time sharing systems where each user needs to get a share of the CPU at regular intervals
Algorithm : non preemptive
First Come First Server (FCFS)this method depended on process arrival time to ready Queue .

Average waiting time is generally not minimal
FCFS is non-preemptive
Not good for time sharing systems where each user needs to get a share of the CPU at regular intervals
Algorithm : non preemptive
First Come First Server (FCFS)this method depended on process arrival time to ready Queue .

Average waiting time is generally not minimal
FCFS is non-preemptive
Not good for time sharing systems where each user needs to get a share of the CPU at regular intervals
Algorithm : non preemptive
example :-
Process
Ready queue arrive time
Cpu burst time
P1
0
3 ms
P2
1
4 ms
P3
4
6 ms
P4
2
4 ms
P5
6
1
find follow:-
.1 draw Gantt chart
.2 compute turnaround time and compute to each process average turnaround time
Practical