/* * Try to keep the most commonly accessed fields in single cache lines * here (16 bytes or greater).  This ordering should be particularly * beneficial on 32-bit processors. * * The first line is data used in page cache lookup, the second line * is used for linear searches (eg. clock algorithm scans).  */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;

/* * Linux kernel virtual memory manager primitives. * The idea being to have a "virtual" mm in the same way * we have a virtual fs - giving a cleaner interface to the * mm details, and allowing different kinds of memory mappings * (from shared memory to executable loading to arbitrary * mmap() functions). *//* * This struct defines a memory VMM memory area. There is one of these * per VM-area/task.  A VM area is any part of the process virtual memory * space that has a special rule for the page-fault handlers (ie a shared * library, the executable area etc). */struct vm_area_struct {    struct mm_struct * vm_mm;    /* VM area parameters */    unsigned long vm_start;    unsigned long vm_end;    /* linked list of VM areas per task, sorted by address */    struct vm_area_struct *vm_next;    pgprot_t vm_page_prot;    unsigned long vm_flags;    /* AVL tree of VM areas per task, sorted by address */    short vm_avl_height;    struct vm_area_struct * vm_avl_left;    struct vm_area_struct * vm_avl_right;    /* For areas with an address space and backing store,     * one of the address_space->i_mmap{,shared} lists,     * for shm areas, the list of attaches, otherwise unused.     */    struct vm_area_struct *vm_next_share;    struct vm_area_struct **vm_pprev_share;    struct vm_operations_struct * vm_ops;    unsigned long vm_pgoff;        /* offset in PAGE_SIZE units, *not* PAGE_CACHE_SIZE */    struct file * vm_file;    unsigned long vm_raend;    void * vm_private_data;        /* was vm_pte (shared mem) */};

struct mm_struct {    struct vm_area_struct * mmap;        /* list of VMAs */    struct vm_area_struct * mmap_avl;    /* tree of VMAs */    struct vm_area_struct * mmap_cache;    /* last find_vma result */    pgd_t * pgd;    atomic_t mm_users;            /* How many users with user space? */    atomic_t mm_count;            /* How many references to "struct mm_struct" (users count as 1) */    int map_count;                /* number of VMAs */    struct semaphore mmap_sem;    spinlock_t page_table_lock;    struct list_head mmlist;        /* List of all active mm‘s */    unsigned long start_code, end_code, start_data, end_data;    unsigned long start_brk, brk, start_stack;    unsigned long arg_start, arg_end, env_start, env_end;    unsigned long rss, total_vm, locked_vm;    unsigned long def_flags;    unsigned long cpu_vm_mask;    unsigned long swap_cnt;  /* number of pages to swap on next pass */    unsigned long swap_address;    /* Architecture-specific MM context */    mm_context_t context;};