Explain Process Management System, Memory Management System in Operating System.
Process Management System1. Traffic Controller :- is that port of operating system thatconstantly checks processor and status of processes.
2. Job Scheduler :- selects a job from the job queue
submitted to the system for execution.
3. Process Scheduler :- decides when a process is to be
executed in the case of multiprogramming
4. Dispatcher : - allocates the processor for a particular
process which is chosen by process scheduler.
5. I/O traffic :- is a program which constantly keeps the
track of I/O devices, channels, control processors
6. I/O Scheduler :- decides which device is to be allocated to
which process.
7. File System : - is a collection of functions which are used
to find status, usage and location of a file. From this all
information's can be easily find which are stored on a
disk in the form of files.
Process Management System
Operating System manages many kind of activities
User program
System program :- printer spoolers, name servers, file servers
etc.
Each is encapsulated in a process
A process includes the complete execution context (code, data,
PC Register, operating system resources in use etc.)
A process is not program
A process is one instance of a program at the time of its
execution. Many processes can be running the same program.
Operating System must : -
Create, delete, suspend, resume and schedule processes.
Supports inter-process communication and synchronization,
handle deadlock.
Memory Management SystemI. Primary (Main) Memory
I. Provide direct access storage for CPU.
II. Processes must be in main memory to execute.
II. Operating system must
I. Policies what should be done?
a. Decide when to load each process into memory.
b. Decide how much memory space to allocate each process.
c. Decide when a process should be removed from memory.
II. Mechanism (How it should be done?)
a. Keep track of memory in use
b. Keep track of unused (free) memory
c. Protect memory space
d. Allocate, deallocate spaces for process spaces for processes
e. Swap processes : memory ----------disk