CPU scheduling is the basis of multiprogramming operating system.
5.1 CPU scheduler
CPU scheduling task is to choose a waiting process from the ready queue, it did not allocate CPU. The process of selecting short-term scheduler, a scheduler selection process can be performed from memory and assign CPU.
5.1.1 preemptive scheduling
If necessary CPU scheduling can be divided into the following four categories:
- When a process of switching from an operating state to a waiting state (e.g., I / O request or a wait () call to wait for the child process terminates)