Operating System Scheduling Method

Scheduling or scheduling is a method of operating systems that regulate the processes that will run in an operating system. This is necessary because the current computer-based multiprogramming. So that in a time would take two or more processing. Tanenbaum said, part of the operating system called scheduller make choices, while the algorithm used is called schedulling algorithm.
Mostly the scheduling can be divided into two major groups, namely:

1. Non-preemptive In this method, if a process has been running the operating system or other operating can not take over the execution processor. The transfer processor can only be done if the process had been stopped. This method is used in batch and sequential systems 2. Preemptive This method is more sophisticated than in the non-preemptive, because the operating system and other operations can be executed over mengamvil processor without having to wait for other processes that are running stopped. This method digunakna in real-time systems. Scheduling process performed by the operating system is triggered from a few things namely: 1. The process of changing from running to blocked status, this can occur when a process of doing system calls to request the operation I / O 2. The process of changing from running to ready status, this can occur when a status process that has been running its time slice. 3. The process changed from blocked to ready status, in this case is a continuation of the trigger number 1 above, when the demand for I / O has been met then the process was blocked status changed to ready 4. When a process stops or Terminated. This means that a process has finished running that operating system will then run a process that has been ready. Reference - Kusnadi, et al. Operating System. Yogyakarta: Penerbit Andi. 2008. - Tanenbaum, Andrew S. Modern Operating Systems. New Jersey: Prentice Hall. 2001.