process scheduling is technique that is used when there are limited resources and many processes are competing for them. .Multiprogramming ensure that the processes running all the time .this utilize the CPU. In Time sharing system switches so frequently between the job the user does not feel that machine is being shared by many process or even many users
Uses
- round robin scheduling
- cpu scheduling gantt chart online
Long Term Scheduler :
Long Term Scheduler or job scheduler is used to select from job queue to ready queue in main memory the Long Term Scheduler controls the number of process in main memory is also known as degree of multiprogramming the system slow down if to many process loaded into memory
Short term scheduler :
the short Term Scheduler invoked very fast. A process is allocated to CPU for short period of time it move backed to ready queue if given time is over. if may be executed for milli seconds.
medium term scheduler:
medium term scheduler removes processes temporary from main memory and places them on secondary memory such as disk drive it move back to main memory when it is required its commonly known as swapping out swapping in