Operating Systems chapters
  1. 01OS Structures & System Calls
  2. 02Process & Thread Management
  3. 03CPU Scheduling Algorithms
  4. 04Process Synchronization & Deadlocks
  5. 05Memory Management & Virtual Memory

Chapter 1 · OS

OS Structures & System Calls

4 topics in 1 parts

Key ideas

NEW Admitted READY Scheduler Dispatch Interrupt / Time Slice RUNNING Exit TERMINATED WAITING / I/O
OS Structures & System Calls
Kernel DimensionUser Space PerspectiveKernel Space Perspective
Privilege LevelRing 3 (Restricted instruction set)Ring 0 (Full hardware & MMU access)
Context Switch CostZero (stays in thread context)High (TLB flush, register save to PCB/trapframe)
Memory IsolationIsolated Virtual Address SpaceDirect access to physical DRAM & page tables
Failure ImpactProcess segmentation fault (isolated termination)Kernel panic / BSOD (system crash)

All 4 topics in OS Structures & System Calls

  1. Structures

    • OS Overview & Types
    • User Mode vs Kernel Mode
    • System Calls & fork()
    • Monolithic vs Microkernel