Process management undertakes the allocation of processor to one program.
The operating system controls the job submitted to the system (CPU).
Several algorithms are used to allocate the job to the processor.
Algorithm is a step-by-step method to solve a given problem.
🌟Based on priority.
FIFO (First In First Out) :
This algorithm is based on queuing. Suppose you are standing in a queue to get your notebook corrected from the teacher. The students who stand First in the queue get his/her notebook corrected First and leaves the queue. Then the next student in the queue gets it corrected and so on. This is the basic methodology of the FIFO algorithm.
Now, let us deal with this FIFO a little more technically. The process (A process is basically a program in execution) that enters the queue first is executed First by the CPU, then the next and then the next and so on. The processes are executed in the order in which they enter the queue.
SJF (Shortest Job First):
This algorithm is based on the size of the job.
Take two jobs A and B.
A = 5 kilo bytes
B = 8 kilo bytes
Kilo literally means 1000 but here kilo means 1024. A byte consists of eight bits. A bit can store either TRUE (1) or FALSE(0).
First the job A will be assigned processor time after which B gets its turn.
Jobs are assigned processor time in a circular method. For Example take three jobs A,B,C. First the job A is assigned to CPU then job B and after B job C and the again A,B and C and so on.
Based On Priority:
In this method each job is assigned a Priority. The higher Priority job is awarded favorable treatment. Take two jobs A and B. Let the Priority of A be 5 and Priority B be 7.
Job B is assigned to the processor before job A.
The allocation of processors by process management is also known as the CPU Scheduling. The objectives of the CPU Scheduling should be to maximise.
🌟The CPU utilisation
🌟The number of jobs done In a unit time (throughout) and to minimise the time taken.
Before the execution of the job and to run the job.