FOR FREE MATERIALS
- Introduction: OS
- Booting Process
- Command Interpreter
- Dual mode of operation
- System Calls
- Difference between system call and library call
- Interrupt and Trap
- Introduction
- Scheduling Criteria, Terms and Concepts
- Different Type Scheduling Algorithms
- Longest Job First
- Longest Remaining Time First
- Highest Response Ratio Next (HRRN)
- Priority Scheduling
- Least Completed Next (LCN) Scheduling
- Multi-Level Queue Scheduling
- Multilevel Feedback Queue Scheduling
- Guaranteed Scheduling
- Fair Share Scheduling
- Lottery Scheduling
- Multi-Processor Scheduling
- Deadline Scheduling
- Rate-Monotonic Scheduling
- POSIX Real-Time Scheduling
- Priority Inversion
- Proportional Share Scheduling
- Comparison table of Scheduling Algorithm
- Algorithm Evaluation for Scheduling
- Important concept of MM
- Memory Representation as Address
- Memory layout for a Process
- Logical and Physical Address Space
- Necessity of Memory Management
- Introduction
- Concept of Non-contiguous memory allocation
- Basic concept of Paging
- Address Translation
- Process of Paging Method
- Calculation of Offset for paging
- Calculation of Logical Address Bit and number of Pages
- Calculation of Physical Address Bit and number of Frames
- Calculation of Page Table Size
- Organization of MMU
- Why Page size power of 2
- Paging Address Calculation: example1
- Paging Numeric Problem: Example2
- Paging Address Calculation: Example3
- Paging Address Calculation: Question1
- Some Important Question 2
- Paging Address Translation: Question3
- UGC NET Paging Question
- GATE Paging Question
- Number of information at Page Entry
- Exams Question on Page Entry Information
- Exam Question: Page Entry Information
- Calculates Page Table Entry Size
- Calculates Page Size
- Calculation of Optimal Page Size
- Question on Optimal Page Size
- Hashed Page Table with Example
- Inverted Page Table with Gate Question
- Question on Inverted Page Table
- Multi-Level Paging
- Multi-level paging: Example1
- Multi-level paging: Example2
- Allocation of Frames
- Subject Mock
Foreground and Background Process
There are two type of processes
i) User process: User processes are executed in user mode (Non-privileged mode) and user process can be preempted or suspended at the time of executing. User processes execute user code.
ii) System process: System processes are executed in privileged mode and system processes executed automatically as per requirement without preemption. Operating-system processes execute system code.
There are two ways by which you can run the process
Foreground process: A foreground process is a simple job/process that runs directly in the foreground (Screen) using GUI or CUI mode. This type of process is initiated and executed by the user intervention i.e. it needs certain inputs from the user and gives some output on the screen.
Example:
a) In Linux when we write lscommand in prompt then it shows output directly on the screen.
b) Office Program in windows.
Disadvantage:
When one process is running a long time in the foreground then no other program can be run because the prompt is not available until the previous one completed.
Background Process:
A process is called a background process when it is run behind (background) the system and without user intervention (No need of user input). Generally, the background process is a child process generated by a control process for processing long-time computational tasks. Processes that stay in the background to handle some activity such as e-mail, Web pages, news, printing, and so on are called daemons.
Example: System Monitoring, Scheduling, Logging, Antivirus, etc.
Advantages:
Though one long process is running in the background, we can run another process because a prompt is available.
