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