1#ifndef _LINUX_COMPACTION_H
2#define _LINUX_COMPACTION_H
3
4/* Return values for compact_zone() and try_to_compact_pages() */
5/* compaction didn't start as it was deferred due to past failures */
6#define COMPACT_DEFERRED	0
7/* compaction didn't start as it was not possible or direct reclaim was more suitable */
8#define COMPACT_SKIPPED		1
9/* compaction should continue to another pageblock */
10#define COMPACT_CONTINUE	2
11/* direct compaction partially compacted a zone and there are suitable pages */
12#define COMPACT_PARTIAL		3
13/* The full zone was compacted */
14#define COMPACT_COMPLETE	4
15/* For more detailed tracepoint output */
16#define COMPACT_NO_SUITABLE_PAGE	5
17#define COMPACT_NOT_SUITABLE_ZONE	6
18/* When adding new state, please change compaction_status_string, too */
19
20/* Used to signal whether compaction detected need_sched() or lock contention */
21/* No contention detected */
22#define COMPACT_CONTENDED_NONE	0
23/* Either need_sched() was true or fatal signal pending */
24#define COMPACT_CONTENDED_SCHED	1
25/* Zone lock or lru_lock was contended in async compaction */
26#define COMPACT_CONTENDED_LOCK	2
27
28struct alloc_context; /* in mm/internal.h */
29
30#ifdef CONFIG_COMPACTION
31extern int sysctl_compact_memory;
32extern int sysctl_compaction_handler(struct ctl_table *table, int write,
33			void __user *buffer, size_t *length, loff_t *ppos);
34extern int sysctl_extfrag_threshold;
35extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
36			void __user *buffer, size_t *length, loff_t *ppos);
37extern int sysctl_compact_unevictable_allowed;
38
39extern int fragmentation_index(struct zone *zone, unsigned int order);
40extern unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
41			int alloc_flags, const struct alloc_context *ac,
42			enum migrate_mode mode, int *contended);
43extern void compact_pgdat(pg_data_t *pgdat, int order);
44extern void reset_isolation_suitable(pg_data_t *pgdat);
45extern unsigned long compaction_suitable(struct zone *zone, int order,
46					int alloc_flags, int classzone_idx);
47
48extern void defer_compaction(struct zone *zone, int order);
49extern bool compaction_deferred(struct zone *zone, int order);
50extern void compaction_defer_reset(struct zone *zone, int order,
51				bool alloc_success);
52extern bool compaction_restarting(struct zone *zone, int order);
53
54#else
55static inline unsigned long try_to_compact_pages(gfp_t gfp_mask,
56			unsigned int order, int alloc_flags,
57			const struct alloc_context *ac,
58			enum migrate_mode mode, int *contended)
59{
60	return COMPACT_CONTINUE;
61}
62
63static inline void compact_pgdat(pg_data_t *pgdat, int order)
64{
65}
66
67static inline void reset_isolation_suitable(pg_data_t *pgdat)
68{
69}
70
71static inline unsigned long compaction_suitable(struct zone *zone, int order,
72					int alloc_flags, int classzone_idx)
73{
74	return COMPACT_SKIPPED;
75}
76
77static inline void defer_compaction(struct zone *zone, int order)
78{
79}
80
81static inline bool compaction_deferred(struct zone *zone, int order)
82{
83	return true;
84}
85
86#endif /* CONFIG_COMPACTION */
87
88#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
89extern int compaction_register_node(struct node *node);
90extern void compaction_unregister_node(struct node *node);
91
92#else
93
94static inline int compaction_register_node(struct node *node)
95{
96	return 0;
97}
98
99static inline void compaction_unregister_node(struct node *node)
100{
101}
102#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
103
104#endif /* _LINUX_COMPACTION_H */
105