Study Guide
Processes, scheduling, synchronisation, deadlocks, memory management and
file systems
Complete Study Guide | Key Concepts | Examples | Practice Questions
, 1. What an Operating System Does
The OS manages hardware and provides services to programs: process management, memory management, file
systems, I/O and security. It acts as both resource manager and extended machine.
- Kernel vs user mode: privileged instructions run only in kernel mode; system calls are the controlled gateway.
- Monolithic kernels (Linux) vs microkernels (Minix): speed of direct calls vs isolation of services.
- Batch, time-sharing, real-time and embedded are the classic OS types - know one example of each.
- System calls: fork(), exec(), open(), read(), write() - the exam list to memorise.
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