Linux kernel mirror (for testing)
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1#ifndef __LINUX_PAGE_EXT_H
2#define __LINUX_PAGE_EXT_H
3
4#include <linux/types.h>
5#include <linux/stacktrace.h>
6#include <linux/stackdepot.h>
7
8struct pglist_data;
9struct page_ext_operations {
10 bool (*need)(void);
11 void (*init)(void);
12};
13
14#ifdef CONFIG_PAGE_EXTENSION
15
16/*
17 * page_ext->flags bits:
18 *
19 * PAGE_EXT_DEBUG_POISON is set for poisoned pages. This is used to
20 * implement generic debug pagealloc feature. The pages are filled with
21 * poison patterns and set this flag after free_pages(). The poisoned
22 * pages are verified whether the patterns are not corrupted and clear
23 * the flag before alloc_pages().
24 */
25
26enum page_ext_flags {
27 PAGE_EXT_DEBUG_POISON, /* Page is poisoned */
28 PAGE_EXT_DEBUG_GUARD,
29 PAGE_EXT_OWNER,
30#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
31 PAGE_EXT_YOUNG,
32 PAGE_EXT_IDLE,
33#endif
34};
35
36/*
37 * Page Extension can be considered as an extended mem_map.
38 * A page_ext page is associated with every page descriptor. The
39 * page_ext helps us add more information about the page.
40 * All page_ext are allocated at boot or memory hotplug event,
41 * then the page_ext for pfn always exists.
42 */
43struct page_ext {
44 unsigned long flags;
45#ifdef CONFIG_PAGE_OWNER
46 unsigned int order;
47 gfp_t gfp_mask;
48 int last_migrate_reason;
49 depot_stack_handle_t handle;
50#endif
51};
52
53extern void pgdat_page_ext_init(struct pglist_data *pgdat);
54
55#ifdef CONFIG_SPARSEMEM
56static inline void page_ext_init_flatmem(void)
57{
58}
59extern void page_ext_init(void);
60#else
61extern void page_ext_init_flatmem(void);
62static inline void page_ext_init(void)
63{
64}
65#endif
66
67struct page_ext *lookup_page_ext(struct page *page);
68
69#else /* !CONFIG_PAGE_EXTENSION */
70struct page_ext;
71
72static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
73{
74}
75
76static inline struct page_ext *lookup_page_ext(struct page *page)
77{
78 return NULL;
79}
80
81static inline void page_ext_init(void)
82{
83}
84
85static inline void page_ext_init_flatmem(void)
86{
87}
88#endif /* CONFIG_PAGE_EXTENSION */
89#endif /* __LINUX_PAGE_EXT_H */