Introduction Job Scheduling Versus Process Scheduling Process Scheduler Process Identification Process Status Process State Accounting Process Scheduling Policies Process Scheduling Algorithms Cache Memory Interrupts. Job Scheduling Process Scheduling Interrupt Management.
Job Scheduling Versus Process Scheduling
Process Scheduling Policies
Process Scheduling Algorithms
I/O or event completion
I/O or event wait
Handled by Process Scheduler
Handled by Job Scheduler
Maximize throughput by running as many jobs as possible in a given amount of time.
Maximize CPU efficiency by keeping CPU busy 100 % of time.
Ensure fairness for all jobs by giving everyone an equal amount of CPU and I/O time.
Minimize response time by quickly turning around interactive requests.
Minimize turnaround time by moving entire jobs in/out of system quickly.
Minimize waiting time by moving jobs out of READY queue as quickly as possible.
ProcessCPU Burst (Turnaround Time)
What does the time line look like?
What’s the average turnaround time?
first come first served
multiple level queues
non-preemptive scheduling policy
preemptive scheduling policy
Process Control Block
process scheduling algorithm
process scheduling policyprocess status
shortest job next (SJN)
shortest remaining time