Operating Systems

Your program never talks to hardware directly. Between your code and the CPU, the disks, the network card, and the display sits the operating system — software that abstracts over the machine so every program sees a clean, consistent interface. Understanding what the OS does explains a large fraction of the performance characteristics and failure modes you encounter in real systems.

This track covers three lessons:

• Processes and threads — what an OS does, the isolation boundary between processes, and what state each thread owns privately
• Scheduling and virtual memory — how the OS decides which thread runs next, and how each process gets its own private address space
• Context switching and system calls — the cost of switching between threads, and how user code crosses into the kernel