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 __update_lru_size(struct lruvec *lruvec,
  26                                enum lru_list lru, enum zone_type zid,
  27                                int nr_pages)
  28{
  29        struct pglist_data *pgdat = lruvec_pgdat(lruvec);
  30
  31        __mod_node_page_state(pgdat, NR_LRU_BASE + lru, nr_pages);
  32        __mod_zone_page_state(&pgdat->node_zones[zid],
  33                                NR_ZONE_LRU_BASE + lru, nr_pages);
  34}
  35
  36static __always_inline void update_lru_size(struct lruvec *lruvec,
  37                                enum lru_list lru, enum zone_type zid,
  38                                int nr_pages)
  39{
  40        __update_lru_size(lruvec, lru, zid, nr_pages);
  41#ifdef CONFIG_MEMCG
  42        mem_cgroup_update_lru_size(lruvec, lru, nr_pages);
  43#endif
  44}
  45
  46static __always_inline void add_page_to_lru_list(struct page *page,
  47                                struct lruvec *lruvec, enum lru_list lru)
  48{
  49        update_lru_size(lruvec, lru, page_zonenum(page), hpage_nr_pages(page));
  50        list_add(&page->lru, &lruvec->lists[lru]);
  51}
  52
  53static __always_inline void del_page_from_lru_list(struct page *page,
  54                                struct lruvec *lruvec, enum lru_list lru)
  55{
  56        list_del(&page->lru);
  57        update_lru_size(lruvec, lru, page_zonenum(page), -hpage_nr_pages(page));
  58}
  59
  60/**
  61 * page_lru_base_type - which LRU list type should a page be on?
  62 * @page: the page to test
  63 *
  64 * Used for LRU list index arithmetic.
  65 *
  66 * Returns the base LRU type - file or anon - @page should be on.
  67 */
  68static inline enum lru_list page_lru_base_type(struct page *page)
  69{
  70        if (page_is_file_cache(page))
  71                return LRU_INACTIVE_FILE;
  72        return LRU_INACTIVE_ANON;
  73}
  74
  75/**
  76 * page_off_lru - which LRU list was page on? clearing its lru flags.
  77 * @page: the page to test
  78 *
  79 * Returns the LRU list a page was on, as an index into the array of LRU
  80 * lists; and clears its Unevictable or Active flags, ready for freeing.
  81 */
  82static __always_inline enum lru_list page_off_lru(struct page *page)
  83{
  84        enum lru_list lru;
  85
  86        if (PageUnevictable(page)) {
  87                __ClearPageUnevictable(page);
  88                lru = LRU_UNEVICTABLE;
  89        } else {
  90                lru = page_lru_base_type(page);
  91                if (PageActive(page)) {
  92                        __ClearPageActive(page);
  93                        lru += LRU_ACTIVE;
  94                }
  95        }
  96        return lru;
  97}
  98
  99/**
 100 * page_lru - which LRU list should a page be on?
 101 * @page: the page to test
 102 *
 103 * Returns the LRU list a page should be on, as an index
 104 * into the array of LRU lists.
 105 */
 106static __always_inline enum lru_list page_lru(struct page *page)
 107{
 108        enum lru_list lru;
 109
 110        if (PageUnevictable(page))
 111                lru = LRU_UNEVICTABLE;
 112        else {
 113                lru = page_lru_base_type(page);
 114                if (PageActive(page))
 115                        lru += LRU_ACTIVE;
 116        }
 117        return lru;
 118}
 119
 120#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
 121
 122#endif
 123