CPU Scheduling Policies
This lecture covers CPU scheduling concepts and policies including FIFO, SJF, STCF, Round Robin, trade-offs in response time vs turnaround time, handling IO, and scheduling metrics like response and turnaround time.
CPU Virtualization Mechanisms
This document explains how OS virtualizes the CPU using limited direct execution, managing mode switches between user/kernel, system call trapping, timer interrupts, and context switching to achieve efficient and controlled process execution.
Introduction to Operating Systems
An introduction to operating systems focusing on their role as system software managing hardware, process management, memory management, IO, and system calls. It discusses OS architectures like monolithic kernels and microkernels and the need for OS in convenience, security, and resource usage efficiency.
Threads
This lecture explains threads as lightweight processes sharing memory space. It discusses thread control blocks, POSIX threads in Linux, concurrency issues like race conditions, critical sections, locks, and synchronization primitives.
Kernel Mode Execution
This lecture explains the distinction between user mode and kernel mode execution in OS. It details how system calls and interrupts trap the CPU to kernel mode, context saving on kernel stack, interrupt descriptor table (IDT), and context switching in kernel mode.