Processor Management – In case of multiprogramming environment system gets multiple programs for execution and operating system has to decide which program should be send to CPU for execution and for how much time. Actually this process is called as process scheduling in which operating system decide which process needs to get into the CPU for execution and how much time span is required. Assigning and de-assigning of process is charge of operating system. CPU can execute one single process at a time so its selection is done by operating system. Operating system use a separate program to hold the status of processor to provide information about is it free or busy in process execution. Traffic controller is used to keep processor’s status information.
If the processor or CPU already have a process which is currently being executed, then operating system does not let any other process to get into the CPU for execution in this condition process sets in to a wait condition. Assigning processor or CPU to a process is called as processor allocation. When a CPU execute a process absolutely it has to deallocate that process. The process of completion of a program or process under the execution of CUP is called as deallocation of processor because processor transfer the processed information to the user. In this case processor gets free from process and ready to get new process for execution. In case of processor management operating system perform the activities
- It keeps the track of processor status and processor itself. (The program which is responsible for this task is called as traffic controller)
- Allocates the processor or CPU to a Process.
- Deallocates the processor or CPU by a process.
Operating system helps in deallocating CPU when the processor is no longer required for process execution. Computer system gets a bulks of processes for execution which are kept in different queues according to the scheduling algorithms. According to conditions processes gets the CPU.