2018年10月7日21:37:07评论1.1K

How Linux Works 2nd Edition content validity

Unlike some operating systems, Linux doesn’t try to hide the important bits from you-it gives you full control of your computer. But to truly master Linux, you need to understand its internals, like how the system boots, how networking works, and what the kernel actually does.

In this completely revised second edition of the perennial best seller How Linux Works, author Brian Ward makes the concepts behind Linux internals accessible to anyone curious about the inner workings of the operating system. Inside, you’ll find the kind of knowledge that normally comes from years of experience doing things the hard way. You’ll learn:

How Linux boots, from boot loaders to init implementations (systemd, Upstart, and System V)

How the kernel manages devices, device drivers, and processes

How networking, interfaces, firewalls, and servers work

How development tools work and relate to shared libraries

How to write effective shell scripts

You’ll also explore the kernel and examine key system tasks inside user space, including system calls, input and output, and filesystems. With its combination of background, theory, real-world examples, and patient explanations, How Linux Works will teach you what you need to know to solve pesky problems and take control of your operating system.

How Linux Works 2nd Edition Wonderful Digest

1.3 The Kernel

Why are we talking about main memory and states? Nearly everything that the kernel does revolves around main memory. One of the kernel’s tasks is to split memory into many subdivisions, and it must maintain certain state information about those subdivisions at all times. Each process gets its own share of memory, and the kernel must ensure that each process keeps to its share.

The kernel is in charge of managing tasks in four general system areas:

Processes. The kernel is responsible for determining which processes are allowed to use the CPU.

Memory. The kernel needs to keep track of all memory—what is currently allocated to a particular process,what might be shared between processes, and what is free.

Device drivers. The kernel acts as an interface between hardware (such as a disk) and processes. It’s usually the kernel’s job to operate the hardware.

System calls and support. Processes normally use system calls to communicate with the kernel.

We’ll now briefly explore each of these areas.