驱动中 __init 前缀的作用

static int __init dev_init(void)

在驱动的初始化函数中经常看到，__init 前缀， 这个在下面文件中定义

file:/include/linux/init.h

/* These macros are used to mark some functions or
 * initialized data (doesn't apply to uninitialized data)
 * as `initialization' functions. The kernel can take this
 * as hint that the function is used only during the initialization
 * phase and free up used memory resources after
 *
 * Usage:
 * For functions:
 *
 * You should add __init immediately before the function name, like:
 *
 * static void __init initme(int x, int y)
 * {
 * extern int z; z = x * y;
 * }