Linux物理内存相关数据结构

节点：pg_data_t

typedef struct pglist_data {
    zone_t node_zones[MAX_NR_ZONES];
    zonelist_t node_zonelists[NR_GFPINDEX];
    struct page *node_mem_map;
    unsigned long *valid_addr_bitmap;
    struct bootmem_data *bdata;
    unsigned long node_start_paddr;
    unsigned long node_start_mapnr;
    unsigned long node_size;
    int node_id;
    struct pglist_data *node_next;
} pg_data_t;

所有的节点都由链表pgdat_list维护，所有的节点都在链表中，由函数init_bootmem_core初始化节点。

管理区：struct zone_t

typedef struct zone_struct {
    /*
     * Commonly accessed fields:
     */
    spinlock_t        lock;
    unsigned long        offset;
    unsigned long        free_pages;
    unsigned long        inactive_clean_pages;
    unsigned long        inactive_dirty_pages;
    unsigned long        pages_min, pages_low, pages_high;

    /*
     * free areas of different sizes
     */
    struct list_head    inactive_clean_list;
    free_area_t        free_area[MAX_ORDER];

    /*
     * rarely used fields:
     */
    char            *name;
    unsigned long        size;
    /*
     * Discontig memory support fields.
     */
    struct pglist_data    *zone_pgdat;
    unsigned long        zone_start_paddr;
    unsigned long        zone_start_mapnr;
    struct page        *zone_mem_map;
} zone_t;

页面：page

typedef struct page {
    struct list_head list;
    struct address_space *mapping;
    unsigned long index;
    struct page *next_hash;
    atomic_t count;
    unsigned long flags;    /* atomic flags, some possibly updated asynchronously */
    struct list_head lru;
    unsigned long age;
    wait_queue_head_t wait;
    struct page **pprev_hash;
    struct buffer_head * buffers;
    void *virtual; /* non-NULL if kmapped */
    struct zone_struct *zone;
} mem_map_t;