struct list_head/LIST_HEAD以及LIST_HEAD_INIT/INIT_LIST_HEAD

仅仅为struct list_head相关的两个宏:

#define LIST_HEAD_INIT(name) { &(name), &(name) }

#define LIST_HEAD(name) \
        struct list_head name = LIST_HEAD_INIT(name)


static inline void INIT_LIST_HEAD(struct list_head *list)
{
        list->next = list;
        list->prev = list;
}

定义了双向链表的头节点

可以如下:
LIST_HEAD(head);
或者:
struct list_head head;
LIST_HEAD_INIT(head);

#define LIST_HEAD_INIT(name) { &(name), &(name) } 

用head的地址初始化其两个成员next和prev ，使其都指向自己

struct list_head {
        struct list_head *next, *prev;
};