LXR linux/include/linux/mm

   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 */
  20static inline int page_is_file_cache(struct page *page)
  21{
  22        return !PageSwapBacked(page);
  23}
  24
  25static __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
  34static __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 */
  51static 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 */
  65static __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 */
  89static __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
 106