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