include/linux/mm_inline.h

   1 #ifndef LINUX_MM_INLINE_H
   2 #define LINUX_MM_INLINE_H
   3
   4 #include <linux/huge_mm.h>
   5 #include <linux/swap.h>
   6
   7 /**
   8  * page_is_file_cache - should the page be on a file LRU or anon LRU?
   9  * @page: the page to test
  10  *
  11  * Returns 1 if @page is page cache page backed by a regular filesystem,
  12  * or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed.
  13  * Used by functions that manipulate the LRU lists, to sort a page
  14  * onto the right LRU list.
  15  *
  16  * We would like to get this info without a page flag, but the state
  17  * needs to survive until the page is last deleted from the LRU, which
  18  * could be as far down as __page_cache_release.
  19  */
  20 static inline int page_is_file_cache(struct page *page)
  21 {
  22         return !PageSwapBacked(page);
  23 }
  24
  25 static __always_inline void add_page_to_lru_list(struct page *page,
  26                                 struct lruvec *lruvec, enum lru_list lru)
  27 {
  28         int nr_pages = hpage_nr_pages(page);
  29         mem_cgroup_update_lru_size(lruvec, lru, nr_pages);
  30         list_add(&page->lru, &lruvec->lists[lru]);
  31         __mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, nr_pages);
  32 }
  33
  34 static __always_inline void del_page_from_lru_list(struct page *page,
  35                                 struct lruvec *lruvec, enum lru_list lru)
  36 {
  37         int nr_pages = hpage_nr_pages(page);
  38         mem_cgroup_update_lru_size(lruvec, lru, -nr_pages);
  39         list_del(&page->lru);
  40         __mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, -nr_pages);
  41 }
  42
  43 /**
  44  * page_lru_base_type - which LRU list type should a page be on?
  45  * @page: the page to test
  46  *
  47  * Used for LRU list index arithmetic.
  48  *
  49  * Returns the base LRU type - file or anon - @page should be on.
  50  */
  51 static inline enum lru_list page_lru_base_type(struct page *page)
  52 {
  53         if (page_is_file_cache(page))
  54                 return LRU_INACTIVE_FILE;
  55         return LRU_INACTIVE_ANON;
  56 }
  57
  58 /**
  59  * page_off_lru - which LRU list was page on? clearing its lru flags.
  60  * @page: the page to test
  61  *
  62  * Returns the LRU list a page was on, as an index into the array of LRU
  63  * lists; and clears its Unevictable or Active flags, ready for freeing.
  64  */
  65 static __always_inline enum lru_list page_off_lru(struct page *page)
  66 {
  67         enum lru_list lru;
  68
  69         if (PageUnevictable(page)) {
  70                 __ClearPageUnevictable(page);
  71                 lru = LRU_UNEVICTABLE;
  72         } else {
  73                 lru = page_lru_base_type(page);
  74                 if (PageActive(page)) {
  75                         __ClearPageActive(page);
  76                         lru += LRU_ACTIVE;
  77                 }
  78         }
  79         return lru;
  80 }
  81
  82 /**
  83  * page_lru - which LRU list should a page be on?
  84  * @page: the page to test
  85  *
  86  * Returns the LRU list a page should be on, as an index
  87  * into the array of LRU lists.
  88  */
  89 static __always_inline enum lru_list page_lru(struct page *page)
  90 {
  91         enum lru_list lru;
  92
  93         if (PageUnevictable(page))
  94                 lru = LRU_UNEVICTABLE;
  95         else {
  96                 lru = page_lru_base_type(page);
  97                 if (PageActive(page))
  98                         lru += LRU_ACTIVE;
  99         }
 100         return lru;
 101 }
 102
 103 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
 104
 105 #endif