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linux操作系统内核编程-----LINUX系统开发非常好的资料

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注
1.1我没有以root身份编译是因为用root做的事情越少，系统就越安全。我是做计算机安全
工作的，所以比较偏执。
3.1这是在2.0版本中。在2.2中如果把索引节点设为0这是自动完成的。
4.1这两个的区别是文件操作是处理文件本身，而索引节点操作时处理引用文件的方法，比
如创建连接。
5.1注意这里读和写角色再次换位，在ioctl中读是向内核发信息，而写是从内核读信息。
5.2 这是不确切的。比如你不能通过ioctl传递一个结构体，但是可以传递指向它的指针。
6.1 不可能有。因为在C语言中目标文件只有全局变量的地址，而不是类型。这就是为什么
头文件是必要的。
8.1 最简单的把文件保持打开状态的方法是用tail –f打开。
8.2 这是说进程仍在内核——对于进程来说，它发出open系统调用，而这个系统调用还没
有返回。多数情况下，在发出系统调用和返回之间的时间内，进程不知道别人在使用CPU。
8.3 这是因为我们使用了module_interruptible_sleep_on。我们可以使用module_sleep_on，但
是会激怒那些控制程序被打扰的用户。
9.1 Teletype，最初是用来和Unix系统通信的键盘-打印机的结合体，现在成了Unix程序的
文本流的概括，无论是物理终端、X显示的一个xterm、网络连接还是其他。
10.1 它们其实是一样的。
11.1 这是Linux发源的Intel结构上的标准方法。
11.2 queue_task_irq是用一个全局锁来保护不受此影响，在2.2中没有queue_task_irq，而
queue_task是被锁保护的。
12.1 例外是线连进程，可以同时在几个CPU上运行。
12.2 表示可以在SMP中可以安全使用。
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