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 del_page_from_lru(struct zone *zone, struct page *page) 42 { 43 enum lru_list l = LRU_BASE; 44 45 list_del(&page->lru); 46 if (PageUnevictable(page)) { 47 __ClearPageUnevictable(page); 48 l = LRU_UNEVICTABLE; 49 } else { 50 if (PageActive(page)) { 51 __ClearPageActive(page); 52 l += LRU_ACTIVE; 53 } 54 l += page_is_file_cache(page); 55 } 56 __dec_zone_state(zone, NR_LRU_BASE + l); 57 } 58 59 /** 60 * page_lru - which LRU list should a page be on? 61 * @page: the page to test 62 * 63 * Returns the LRU list a page should be on, as an index 64 * into the array of LRU lists. 65 */ 66 static inline enum lru_list page_lru(struct page *page) 67 { 68 enum lru_list lru = LRU_BASE; 69 70 if (PageUnevictable(page)) 71 lru = LRU_UNEVICTABLE; 72 else { 73 if (PageActive(page)) 74 lru += LRU_ACTIVE; 75 lru += page_is_file_cache(page); 76 } 77 78 return lru; 79 } 80 81 /** 82 * inactive_anon_is_low - check if anonymous pages need to be deactivated 83 * @zone: zone to check 84 * 85 * Returns true if the zone does not have enough inactive anon pages, 86 * meaning some active anon pages need to be deactivated. 87 */ 88 static inline int inactive_anon_is_low(struct zone *zone) 89 { 90 unsigned long active, inactive; 91 92 active = zone_page_state(zone, NR_ACTIVE_ANON); 93 inactive = zone_page_state(zone, NR_INACTIVE_ANON); 94 95 if (inactive * zone->inactive_ratio < active) 96 return 1; 97 98 return 0; 99 } 100 #endif 101