OS Process Scheduling Flashcards
Process execution consists of a cycle of CPU execution and I/O wait
CPU-I/O BURST CYCLE
when the CPU is running we call it?
a burst
keep the CPU as busy as possible
CPU utilization
of processes that complete their execution per time unit
throughput
amount of time to execute a particular process
turnaround time
amount of time a process has been waiting in the ready queue
waiting time
amount of time it takes from when a request was submitted until the first response is produced, not output (for a time-sharing environment)
response time
Scheduling Algorithm Optimization Criteria:
Max CPU utilization
- Max throughput
- Min turnaround time
- Min waiting time
-Min response time
short process behind long process
convoy effect
the time arrives - the time started so
waiting time
the time it stopped running - the arrival time
turnaround time
low priority processes may never execute
problem = starvation
as time progresses increase the priority of the process
solution = aging
- Each process gets a small unit of CPU time (time quantum q), usually 10-100 milliseconds. After this time has elapsed, the process is preempted and added to the end of the ready queue.
Round Robin
