Process Management: Processes

Question 1

A Process is the basic unit of execution in an operating system

Answer 1

Each process has a number, its process identifier (pid)

Question 2

Different processes may run

Answer 2

different instances of the same program

Ex: my gcc and your gcc process both run c compiler

Question 3

At a minimum,

Answer 3

process execution requires following resources:

Memory to contain the program code and data
A set of CPU registers to support execution

Question 4

Modern OS run

Answer 4

multiple processes concurrently

Examples: (can all run simultaneously):
o gcc hello_world.c – compiler running on hello_world file
o gcc read_A.c – compiler running on read_A file
o emacs – text editor
o firefox – web browser

Question 5

Steps of program to process:

Answer 5

when first we write the program in e.g C

then the compiler turns that program into an instruction list

OS delivers the instruction list to the processor

then The CPU interprets the instruction list

Question 6

Process has its own address space:

Answer 6

.The program code, also called text section

. Current activity including program counter,
processor registers

. Stack containing temporary data
. Function parameters
. return addresses
. local variables

. Data section containing global variables

. Heap containing memory dynamically
allocated during run time

Question 7

As a process executes, it changes state

Answer 7

. new: The process is being created
. running: Instructions are being executed
. waiting: The process is waiting for some event to occur
. ready: The process is waiting to be assigned to a processor
. terminated: the process has finished execution

Question 8

Each process is represented in the operating system

Answer 8

by a process control block (PCB)

Question 9

The goal of scheduling is to Maximize

Answer 9

CPU use, quickly switch processes onto CPU for time sharing