quartz/content/notes/19-cpu-scheduling.md

title	aliases	tags
19-cpu-scheduling		cosc204 lecture

why shedule?

• keep cpu busy (cpu utilisation)
• so processed dont hae to spend time waithing for the CPU
  • even if cpu is always bust executing processses in different orders can change the average time spent in queue
• cpu burst
  • 
  • (diagram is old the timing will have changed)
  • between burst - waiting for io
• so that interactive processes respond quickly
  • time spent waiting in total
  • average time between visits to CPU
  • 

criteria

• CPU utilisation - % time CPU is busy
• throughput - number of processes completed per time unit
• turnaround time - (for a single process) length of time from submitted to completed
• waiting time - (for a single process) time spent waiting for the CPU
• response time - (for a signle process) average timefrom the submission of a request to a process util the first response in produced

Scheduling algorithms