Issues With Multilevel Queue

• Processes show a varying character
  • Interactive or non-interactive
  • Response requirement: high to low
• Processes in low level of priority may starve
• Solution: Add movement of processes from one queue to another
• Multilevel Feedback Queue Scheduling
• Movement can be due to
  • Change in character of the process
  • Aging

Scheduling in Real time OS

• Real time jobs have an additional criterion
  • Deadline, or time guarantee to execute a process
• Earliest Deadline First (EDF) Scheduling
  • Schedule a task that has earliest deadline

EDF Examples