xv6 Kernel Modifications

About the Project

Enhanced the XV6 operating system with new system calls and scheduling policies. Implemented:

• System call tracking functionality
• Process timer alerts
• Lottery-based scheduling
• Multi-level feedback queue scheduling

GitHub

Features

System Calls

• getSysCount: Tracks system call usage statistics
• sigalarm/sigreturn: Process CPU time alerts
• settickets: Sets process lottery tickets

Schedulers

• Lottery Based Scheduling (LBS)

  • Random ticket-based process selection
  • Process arrival time prioritization
  • Inherited ticket counts for child processes

• Multi-Level Feedback Queue (MLFQ)

  • 4 priority queues with different time slices
  • Priority boosting to prevent starvation
  • I/O-bound process prioritization