Chapter 3Kernel Services

3.1 Kernel Organization

The 4.4BSD kernel can be viewed as a service provider to user processes. Processes usually access these services through system calls. Some services, such as process scheduling and memory management, are implemented as processes that execute in kernel mode or as routines that execute periodically within the kernel. In this chapter, we describe how kernel services are provided to user processes, and what some of the ancillary processing performed by the kernel is. Then, we describe the basic kernel services provided by 4.4BSD, and provide details of their implementation.

System Processes

All 4.4BSD processes originate from a single process that is crafted by the kernel at startup. Three processes ...

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