#define list_entry(ptr, type, member) \
container_of(ptr, type, member)

//container_of()宏的定义在kernel.h头文件中。
#define container_of(ptr, type, member) ({      \
const typeof( ((type *)0)->member ) *__mptr = (ptr);  \
(type *)( (char *)__mptr - offsetof(type,member) );})

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

//<drivers/block/osdblk.c>
static LIST_HEAD(osdblkdev_list);
struct osdblk_device {
    int			id;		/* blkdev unique id */
    int			major;		/* blkdev assigned major */
    ...
    struct list_head	node;
    char			osd_path[0];	/* OSD device path */
};

static ssize_t class_osdblk_list(struct class *c,
    struct class_attribute *attr,
    char *data)
{
    int n = 0;
    struct list_head *tmp;
    list_for_each(tmp, &osdblkdev_list) {
        struct osdblk_device *osdev;
        osdev = list_entry(tmp, struct osdblk_device, node);
        n += sprintf(data+n, "%d %d %llu %llu %s\n",
            osdev->id,
            osdev->major,
            osdev->obj.partition,
            osdev->obj.id,
            osdev->osd_path);
    }
    return n;
}

<include/linux/list.h>

#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;
}

//<include/linux/types.h>
struct list_head {
    struct list_head *next, *prev;
};

<include/linux/mm_types.h>
struct page {
    struct list_head lru;
    ...
}

//<include/linux/list.h>
void list_add(struct list_head *new, struct list_head *head)
void list_add_tail(struct list_head *new, struct list_head *head)

#define list_for_each(pos, head) \
for (pos = (head)->next; pos != (head); pos = pos->next)

<arch/x86/include/asm/linkage.h>
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))

<include/linux/linkage.h>
#define asmlinkage CPP_ASMLINKAGE

__builtin_prefetch(const void *addr, int rw, int locality)

//<include/linux/prefetch.h>
#define prefetch(x) __builtin_prefetch(x)
#define prefetchw(x) __builtin_prefetch(x,1)

//<mm/page_alloc.c>
void __init __free_pages_bootmem(struct page *page, unsigned int order)
{
    unsigned int nr_pages = 1 << order;
    struct page *p = page;
    unsigned int loop;
    prefetchw(p);
    for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
        prefetchw(p + 1);
        __ClearPageReserved(p);
        set_page_count(p, 0);
    }
    …
}

#define LIKELY(x) __builtin_expect(!!(x), 1) //x很可能为真
#define UNLIKELY(x) __builtin_expect(!!(x), 0) //x很可能为假

#define __swab16(x)        \
(__builtin_constant_p((__u16)(x)) ?  \
___constant_swab16(x) :      \
__fswab16(x))

struct test
{
    char a;
    int x[2] __attribute__ ((packed));
};