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1 | #ifndef _LINUX_COMPACTION_H |
2 | #define _LINUX_COMPACTION_H | |
3 | ||
56de7263 MG |
4 | /* Return values for compact_zone() and try_to_compact_pages() */ |
5 | /* compaction didn't start as it was not possible or direct reclaim was more suitable */ | |
6 | #define COMPACT_SKIPPED 0 | |
7 | /* compaction should continue to another pageblock */ | |
8 | #define COMPACT_CONTINUE 1 | |
9 | /* direct compaction partially compacted a zone and there are suitable pages */ | |
10 | #define COMPACT_PARTIAL 2 | |
11 | /* The full zone was compacted */ | |
12 | #define COMPACT_COMPLETE 3 | |
748446bb | 13 | |
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14 | #ifdef CONFIG_COMPACTION |
15 | extern int sysctl_compact_memory; | |
16 | extern int sysctl_compaction_handler(struct ctl_table *table, int write, | |
17 | void __user *buffer, size_t *length, loff_t *ppos); | |
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18 | extern int sysctl_extfrag_threshold; |
19 | extern int sysctl_extfrag_handler(struct ctl_table *table, int write, | |
20 | void __user *buffer, size_t *length, loff_t *ppos); | |
56de7263 MG |
21 | |
22 | extern int fragmentation_index(struct zone *zone, unsigned int order); | |
23 | extern unsigned long try_to_compact_pages(struct zonelist *zonelist, | |
24 | int order, gfp_t gfp_mask, nodemask_t *mask); | |
4f92e258 MG |
25 | |
26 | /* Do not skip compaction more than 64 times */ | |
27 | #define COMPACT_MAX_DEFER_SHIFT 6 | |
28 | ||
29 | /* | |
30 | * Compaction is deferred when compaction fails to result in a page | |
31 | * allocation success. 1 << compact_defer_limit compactions are skipped up | |
32 | * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT | |
33 | */ | |
34 | static inline void defer_compaction(struct zone *zone) | |
35 | { | |
36 | zone->compact_considered = 0; | |
37 | zone->compact_defer_shift++; | |
38 | ||
39 | if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT) | |
40 | zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT; | |
41 | } | |
42 | ||
43 | /* Returns true if compaction should be skipped this time */ | |
44 | static inline bool compaction_deferred(struct zone *zone) | |
45 | { | |
46 | unsigned long defer_limit = 1UL << zone->compact_defer_shift; | |
47 | ||
48 | /* Avoid possible overflow */ | |
49 | if (++zone->compact_considered > defer_limit) | |
50 | zone->compact_considered = defer_limit; | |
51 | ||
52 | return zone->compact_considered < (1UL << zone->compact_defer_shift); | |
53 | } | |
54 | ||
56de7263 MG |
55 | #else |
56 | static inline unsigned long try_to_compact_pages(struct zonelist *zonelist, | |
57 | int order, gfp_t gfp_mask, nodemask_t *nodemask) | |
58 | { | |
59 | return COMPACT_CONTINUE; | |
60 | } | |
61 | ||
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62 | static inline void defer_compaction(struct zone *zone) |
63 | { | |
64 | } | |
65 | ||
66 | static inline bool compaction_deferred(struct zone *zone) | |
67 | { | |
68 | return 1; | |
69 | } | |
70 | ||
76ab0f53 MG |
71 | #endif /* CONFIG_COMPACTION */ |
72 | ||
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73 | #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) |
74 | extern int compaction_register_node(struct node *node); | |
75 | extern void compaction_unregister_node(struct node *node); | |
76 | ||
77 | #else | |
78 | ||
79 | static inline int compaction_register_node(struct node *node) | |
80 | { | |
81 | return 0; | |
82 | } | |
83 | ||
84 | static inline void compaction_unregister_node(struct node *node) | |
85 | { | |
86 | } | |
87 | #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */ | |
88 | ||
748446bb | 89 | #endif /* _LINUX_COMPACTION_H */ |