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  */
page_is_file_cache(struct page * page)19 static inline int page_is_file_cache(struct page *page)
20 {
21 	return !PageSwapBacked(page);
22 }
23 
24 static inline void
add_page_to_lru_list(struct zone * zone,struct page * page,enum lru_list lru)25 add_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 
34 static inline void
del_page_from_lru_list(struct zone * zone,struct page * page,enum lru_list lru)35 del_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  */
page_lru_base_type(struct page * page)50 static 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  */
page_off_lru(struct page * page)64 static 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  */
page_lru(struct page * page)88 static 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