include/linux/mm_inline.h

   1 #ifndef LINUX_MM_INLINE_H
   2 #define LINUX_MM_INLINE_H
   3
   4 /**
   5  * page_is_file_cache - should the page be on a file LRU or anon LRU?
   6  * @page: the page to test
   7  *
   8  * Returns LRU_FILE if @page is page cache page backed by a regular filesystem,
   9  * or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed.
  10  * Used by functions that manipulate the LRU lists, to sort a page
  11  * onto the right LRU list.
  12  *
  13  * We would like to get this info without a page flag, but the state
  14  * needs to survive until the page is last deleted from the LRU, which
  15  * could be as far down as __page_cache_release.
  16  */
  17 static inline int page_is_file_cache(struct page *page)
  18 {
  19         if (PageSwapBacked(page))
  20                 return 0;
  21
  22         /* The page is page cache backed by a normal filesystem. */
  23         return LRU_FILE;
  24 }
  25
  26 static inline void
  27 add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
  28 {
  29         list_add(&page->lru, &zone->lru[l].list);
  30         __inc_zone_state(zone, NR_LRU_BASE + l);
  31 }
  32
  33 static inline void
  34 del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list l)
  35 {
  36         list_del(&page->lru);
  37         __dec_zone_state(zone, NR_LRU_BASE + l);
  38 }
  39
  40 static inline void
  41 add_page_to_inactive_anon_list(struct zone *zone, struct page *page)
  42 {
  43         add_page_to_lru_list(zone, page, LRU_INACTIVE_ANON);
  44 }
  45
  46 static inline void
  47 add_page_to_active_anon_list(struct zone *zone, struct page *page)
  48 {
  49         add_page_to_lru_list(zone, page, LRU_ACTIVE_ANON);
  50 }
  51
  52 static inline void
  53 add_page_to_inactive_file_list(struct zone *zone, struct page *page)
  54 {
  55         add_page_to_lru_list(zone, page, LRU_INACTIVE_FILE);
  56 }
  57
  58 static inline void
  59 add_page_to_active_file_list(struct zone *zone, struct page *page)
  60 {
  61         add_page_to_lru_list(zone, page, LRU_ACTIVE_FILE);
  62 }
  63
  64 static inline void
  65 del_page_from_inactive_anon_list(struct zone *zone, struct page *page)
  66 {
  67         del_page_from_lru_list(zone, page, LRU_INACTIVE_ANON);
  68 }
  69
  70 static inline void
  71 del_page_from_active_anon_list(struct zone *zone, struct page *page)
  72 {
  73         del_page_from_lru_list(zone, page, LRU_ACTIVE_ANON);
  74 }
  75
  76 static inline void
  77 del_page_from_inactive_file_list(struct zone *zone, struct page *page)
  78 {
  79         del_page_from_lru_list(zone, page, LRU_INACTIVE_FILE);
  80 }
  81
  82 static inline void
  83 del_page_from_active_file_list(struct zone *zone, struct page *page)
  84 {
  85         del_page_from_lru_list(zone, page, LRU_INACTIVE_FILE);
  86 }
  87
  88 static inline void
  89 del_page_from_lru(struct zone *zone, struct page *page)
  90 {
  91         enum lru_list l = LRU_BASE;
  92
  93         list_del(&page->lru);
  94         if (PageActive(page)) {
  95                 __ClearPageActive(page);
  96                 l += LRU_ACTIVE;
  97         }
  98         l += page_is_file_cache(page);
  99         __dec_zone_state(zone, NR_LRU_BASE + l);
 100 }
 101
 102 /**
 103  * page_lru - which LRU list should a page be on?
 104  * @page: the page to test
 105  *
 106  * Returns the LRU list a page should be on, as an index
 107  * into the array of LRU lists.
 108  */
 109 static inline enum lru_list page_lru(struct page *page)
 110 {
 111         enum lru_list lru = LRU_BASE;
 112
 113         if (PageActive(page))
 114                 lru += LRU_ACTIVE;
 115         lru += page_is_file_cache(page);
 116
 117         return lru;
 118 }
 119
 120 /**
 121  * inactive_anon_is_low - check if anonymous pages need to be deactivated
 122  * @zone: zone to check
 123  *
 124  * Returns true if the zone does not have enough inactive anon pages,
 125  * meaning some active anon pages need to be deactivated.
 126  */
 127 static inline int inactive_anon_is_low(struct zone *zone)
 128 {
 129         unsigned long active, inactive;
 130
 131         active = zone_page_state(zone, NR_ACTIVE_ANON);
 132         inactive = zone_page_state(zone, NR_INACTIVE_ANON);
 133
 134         if (inactive * zone->inactive_ratio < active)
 135                 return 1;
 136
 137         return 0;
 138 }
 139 #endif