Subject Syllabus Hub172+ MCQs3 Topics

Operating Systems

Process management, CPU scheduling algorithms, synchronization & deadlocks, memory management, virtual memory, paging, and file systems.

Topic Syllabus & Revision Notes

High-yield concept summaries, formulas, and common exam pitfalls for each topic.

Topic 1

Operating System

Read concise formulas, core definitions, and exam traps.

View Cheat Sheet & MCQs

Topic 24 Key Rules

Round Robin CPU Scheduling

Round Robin scheduling is designed for time-sharing systems. The CPU scheduler cycles through the ready queue, giving each process a fixed slice of time (quantum). If a process does not complete within its quantum, it is preempted and pushed to the back of the ready queue. As the quantum approaches infinity, no process is ever preempted, resulting in standard FCFS execution.

View Cheat Sheet & MCQs

Topic 34 Key Rules

System Calls & CPU Execution Modes

Modern CPUs use hardware-enforced protection rings to prevent user applications from corrupting system memory or hardware devices. When an application needs to read a file, send network packets, or allocate memory, it cannot execute these actions directly. Instead, it triggers a System Call trap, switching the CPU to Kernel Mode (Ring 0). The kernel processes the request and switches execution back to User Mode.

View Cheat Sheet & MCQs