Chapter 19. A Kernel Overview

In general, looking at kernel crashes requires at least a basic knowledge of what the kernel is supposed to do ” since you're looking for instances where it failed to do it! For those who have not had the opportunity to examine the internal structure of an operating system, this chapter attempts to provide a quick look at some of the basic functions, requirements, and structures you'll need to know about.

An operating system kernel could be considered the "Master Control Program" for the machine, everything that is connected to it, and anything that runs on it. One of the basic functions of an OS is to control resources. Under this heading you will find memory, CPU time, disk space, and access to external devices like tapes or terminals. As a side benefit of this whole process, the kernel will also prevent users from stepping on one another's code or data ” corruption of resources is another area of vital concern.

The UNIX kernel is no different from any other kernel; the same basic requirements hold. It was designed with timesharing in mind, so there is an emphasis on switching rapidly between several processes that are ready to run, giving the illusion that all users have an equal shot at getting things done.