Non-Preemptive Scheduling
Non-Preemptive Scheduling Algorithms Formulas Completion Time = Time at which Process terminates (see Gantt chart) Turnaround Time = Completion time- Arrival time OR waiting time+ Burst Time Waiting Time = Turnaround time – Burst Time Response Time = In Non-Preemptive Response Time= Waiting time Response Ratio = (waiting_time + service_time) / service_time Avg. Turnaround Time = Sum of […]
CPU Scheduling Algorithms
CPU Scheduling Algorithms Deciding which process has to be executed first and which process has to be executed later is done through CPU scheduling algorithms. OS also uses CPU Scheduler to schedule different processes. Types of CPU Scheduling 1. Non-preemptive scheduling Every new process has to wait until the running process finishes its CPU cycle or completes […]
Various Times of Process
Various Times of Process When a process is created, it passes through various time intervals to complete its execution. Before explaining various scheduling algorithms, it is important to explain the various times of the process. Various Times of Process Arrival time: When a process arrives in the ready queue. Completion times: The Time at which a […]
Context Switching
What is Context Switching? Switching the CPU to another process by saving the current state of a running process in PCB. And loading the saved state from PCB for a new process is called context switching. It is a complementary part of a multitasking operating system because multitasking is also happens through it. The following […]
Process Control Block (PCB)
Process Control Block (PCB) There are different attributes of a process. These attributes are stored in the Program Control Block (PCB). An integer, Process ID (PID) is used to represents the PCB. This is also known as the context of the process. OS manages and uses these attributes from the PCB of each process. PCB […]
CPU Schedulers
CPU Schedulers And Its Types CPU Schedulers are also known as CPU Dispatchers. It is a module or program that provides control of the CPU to the process. The Dispatcher executes each context switching. Dispatch latency is the time that is needed by the CPU scheduler to stop one process and start another. The operating […]
Process Scheduling Queues
Process Scheduling Queues Different states of processes use their individual queues to keep the number of processes, known as Process Scheduling Queues. Identical PCB of each process also exists in that queue. The OS maintains the following scheduling Queues. Process queue: The process queue keeps a record of all those processes that exist in secondary […]
Process States || 7-States
Process States || 7-States The process, from its creation to completion, passes through different phases called process states. There are seven basic states of process. Ready, RUN, and WAIT Process States exist in the Main memory. New, Suspended Ready, and Suspended Wait Process states exist in secondary memory. 1. New When a process is created, […]
Introduction to Process Management
Introduction to Process Management Before explaining process management, it is important to explain the terms program and process. Program vs. Process The process is actually a program in running State. But the main difference between program and process is, “Every Program which is written in Low or High-level language like (Assembly, C++, and Java, etc.) […]
Multithreading and Multiprocessing
Multithreading and Multiprocessing In this lecture, we will see Multithreading and Multiprocessing in detail with its comparisons. let’s start with multi-threading, What is Multi-threading? Execution of multiple threads of a single process simultaneously with the help of single or multiple CPUs is called Multi-threading. If we have more than one CPU, then the threads of […]
Multi-Programming Vs. Multitasking
Multi-Programming Vs. Multitasking Multi-programming and multitasking are important operating system concepts that improve system performance and efficiency. This guide explains both concepts in detail with examples, advantages, disadvantages, and a clear comparison for better understanding. What is Multi-Programming? Multi-programming is an early technique where multiple programs are loaded into memory and executed one by one […]
What is System Call?
What is a System Call? A system call is a way through which the CPU can access the kernel mode from the user mode. There are different types of system calls to perform different tasks. When a System Call is generated, the CPU switches from user mode to kernel mode to perform that particular task […]
User Mode vs Kernel Mode
User Mode vs Kernel Mode User Mode and Kernel Mode are two important execution modes in operating systems that control how programs interact with hardware and system resources. Understanding their differences helps students clearly grasp system security, performance, and process management concepts. What is User Mode? User Mode is a restricted execution mode where application […]
Types of Operating Systems
Types of Operating Systems There are 6 major types of Operating Systems, which are given below, 1. Batch Operating System Users of batch OS cannot interact with the computer directly. So, each user puts his job on an offline device like a punch card and submits it to the computer operator. Then, by computer Operator, […]
Operating System
What is an Operating System? Operating system (OS) is an interface through which users can interact with Hardware. Users use the user applications that are executed on hardware through the OS. User applications are MS Office, Games, Firefox, VLC player, Photoshop, and many more. CPU, I/O devices, and Storage devices (i.e., Hard Disk RAM) are […]