Linux Kernel Development, Third Edition

4. Process Scheduling

The prior chapter discussed processes, the operating system abstraction of active program code. This chapter discusses the process scheduler, the kernel subsystem that puts those processes to work.

The process scheduler decides which process runs, when, and for how long. The process scheduler (or simply the scheduler, to which it is often shortened) divides the finite resource of processor time between the runnable processes on a system. The scheduler is the basis of a multitasking operating system such as Linux. By deciding which process runs next, the scheduler is responsible for best utilizing the system and giving users the impression that multiple processes are executing simultaneously.

The idea behind the scheduler ...