Process management and scheduling are fundamental concepts in operating systems that involve managing and scheduling processes to efficiently utilize system resources.

Key Points:

Process Management:

a. Definition and Components:

Process: A program in execution; an instance of a program.

Process Control Block (PCB): A data structure that stores information about a process, such as a process ID, program counter, registers, and resource usage.

b. Process States:

New: The process is being created.

Ready: The process is waiting to be assigned to a processor.

Running: The process is currently being executed.

Blocked: The process is waiting for an event or resource.

Terminated: The process has finished its execution.

c. Process Synchronization:

Ensuring coordination and communication among processes to avoid conflicts and data inconsistency.

Techniques include semaphores, mutexes, and monitors.

(Process Synchronization continued) Process Scheduling:

1. Purpose:

Allocating system resources (CPU time) to processes efficiently and fairly. Minimizing response time, maximizing throughput, and ensuring fairness.

2. Scheduling Criteria:

CPU Utilization: Maximizing CPU usage to keep the system busy.

Throughput: Maximizing the number of processes completed per unit of time.

Turnaround Time: Minimizing the time taken to execute a particular process.

Waiting Time: Minimizing the time spent by a process in the ready queue.

Response Time: Minimizing the time taken to respond to a user's request.

3. Scheduling Algorithms:

First-Come, First-Served (FCFS): Processes are executed in the order they arrive.

Shortest Job Next (SJN): The process with the shortest burst time is executed next.

Round Robin (RR): Processes are executed in a fixed time quantum, allowing fair execution.

Priority Scheduling: Processes are assigned priority levels, and the highest priority process is executed next.

Multilevel Queue Scheduling: Processes are divided into different priority levels, each with its own scheduling algorithm.

d. Scheduling Policies:

Pre-emptive Scheduling: Processes can be interrupted and rescheduled before completing their execution.

Non-Pre-emptive Scheduling: Processes run until completion unless they voluntarily release the CPU.

e. Scheduling in Multiprocessor Systems:

Load Balancing: Distributing processes evenly across multiple processors to utilize system resources efficiently.

Symmetric Multiprocessing (SMP): Each processor performs scheduling independently. Asymmetric Multiprocessing (AMP): A master processor handles the task of process scheduling.