#ifndef LINUX_MM_INLINE_H
  #define LINUX_MM_INLINE_H

  #include <linux/huge_mm.h>

  /**
   * page_is_file_cache - should the page be on a file LRU or anon LRU?
   * @page: the page to test
   *

   * Returns 1 if @page is page cache page backed by a regular filesystem,

   * or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed.
   * Used by functions that manipulate the LRU lists, to sort a page
   * onto the right LRU list.
   *
   * We would like to get this info without a page flag, but the state
   * needs to survive until the page is last deleted from the LRU, which
   * could be as far down as __page_cache_release.
   */
  static inline int page_is_file_cache(struct page *page)
  {

  	return !PageSwapBacked(page);

  }

  static __always_inline void add_page_to_lru_list(struct page *page,
  				struct lruvec *lruvec, enum lru_list lru)

  {

  	int nr_pages = hpage_nr_pages(page);
  	mem_cgroup_update_lru_size(lruvec, lru, nr_pages);

  	list_add(&page->lru, &lruvec->lists[lru]);

  	__mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, nr_pages);

  }

  static __always_inline void del_page_from_lru_list(struct page *page,
  				struct lruvec *lruvec, enum lru_list lru)

  {

  	int nr_pages = hpage_nr_pages(page);
  	mem_cgroup_update_lru_size(lruvec, lru, -nr_pages);

  	list_del(&page->lru);

  	__mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, -nr_pages);

  }

  /**
   * page_lru_base_type - which LRU list type should a page be on?
   * @page: the page to test
   *
   * Used for LRU list index arithmetic.
   *
   * Returns the base LRU type - file or anon - @page should be on.
   */
  static inline enum lru_list page_lru_base_type(struct page *page)
  {
  	if (page_is_file_cache(page))
  		return LRU_INACTIVE_FILE;
  	return LRU_INACTIVE_ANON;
  }

  /**
   * page_off_lru - which LRU list was page on? clearing its lru flags.
   * @page: the page to test
   *
   * Returns the LRU list a page was on, as an index into the array of LRU
   * lists; and clears its Unevictable or Active flags, ready for freeing.
   */

  static __always_inline enum lru_list page_off_lru(struct page *page)

  {

  	enum lru_list lru;

  	if (PageUnevictable(page)) {
  		__ClearPageUnevictable(page);

  		lru = LRU_UNEVICTABLE;

  	} else {

  		lru = page_lru_base_type(page);

  		if (PageActive(page)) {
  			__ClearPageActive(page);

  			lru += LRU_ACTIVE;

  		}

  	}

  	return lru;

  }

  /**
   * page_lru - which LRU list should a page be on?
   * @page: the page to test
   *
   * Returns the LRU list a page should be on, as an index
   * into the array of LRU lists.
   */

  static __always_inline enum lru_list page_lru(struct page *page)

  {

  	enum lru_list lru;

  	if (PageUnevictable(page))
  		lru = LRU_UNEVICTABLE;
  	else {

  		lru = page_lru_base_type(page);

  		if (PageActive(page))
  			lru += LRU_ACTIVE;

  	}

  	return lru;
  }

  
  #endif