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Commit | Line | Data |
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748446bb MG |
1 | #ifndef _LINUX_COMPACTION_H |
2 | #define _LINUX_COMPACTION_H | |
3 | ||
56de7263 | 4 | /* Return values for compact_zone() and try_to_compact_pages() */ |
fa6c7b46 | 5 | /* When adding new states, please adjust include/trace/events/compaction.h */ |
ea7ab982 | 6 | enum compact_result { |
4f9a358c MH |
7 | /* For more detailed tracepoint output - internal to compaction */ |
8 | COMPACT_NOT_SUITABLE_ZONE, | |
ea7ab982 MH |
9 | /* |
10 | * compaction didn't start as it was not possible or direct reclaim | |
11 | * was more suitable | |
12 | */ | |
13 | COMPACT_SKIPPED, | |
1d4746d3 MH |
14 | /* compaction didn't start as it was deferred due to past failures */ |
15 | COMPACT_DEFERRED, | |
4f9a358c | 16 | |
1d4746d3 MH |
17 | /* compaction not active last round */ |
18 | COMPACT_INACTIVE = COMPACT_DEFERRED, | |
19 | ||
4f9a358c MH |
20 | /* For more detailed tracepoint output - internal to compaction */ |
21 | COMPACT_NO_SUITABLE_PAGE, | |
ea7ab982 MH |
22 | /* compaction should continue to another pageblock */ |
23 | COMPACT_CONTINUE, | |
4f9a358c | 24 | |
ea7ab982 | 25 | /* |
4f9a358c MH |
26 | * The full zone was compacted scanned but wasn't successfull to compact |
27 | * suitable pages. | |
ea7ab982 | 28 | */ |
4f9a358c | 29 | COMPACT_COMPLETE, |
c8f7de0b MH |
30 | /* |
31 | * direct compaction has scanned part of the zone but wasn't successfull | |
32 | * to compact suitable pages. | |
33 | */ | |
34 | COMPACT_PARTIAL_SKIPPED, | |
4f9a358c MH |
35 | |
36 | /* compaction terminated prematurely due to lock contentions */ | |
37 | COMPACT_CONTENDED, | |
38 | ||
c8f7de0b | 39 | /* |
4f9a358c MH |
40 | * direct compaction partially compacted a zone and there might be |
41 | * suitable pages | |
c8f7de0b | 42 | */ |
4f9a358c | 43 | COMPACT_PARTIAL, |
ea7ab982 | 44 | }; |
748446bb | 45 | |
1f9efdef VB |
46 | /* Used to signal whether compaction detected need_sched() or lock contention */ |
47 | /* No contention detected */ | |
48 | #define COMPACT_CONTENDED_NONE 0 | |
49 | /* Either need_sched() was true or fatal signal pending */ | |
50 | #define COMPACT_CONTENDED_SCHED 1 | |
51 | /* Zone lock or lru_lock was contended in async compaction */ | |
52 | #define COMPACT_CONTENDED_LOCK 2 | |
53 | ||
1a6d53a1 VB |
54 | struct alloc_context; /* in mm/internal.h */ |
55 | ||
76ab0f53 | 56 | #ifdef CONFIG_COMPACTION |
bda807d4 MK |
57 | extern int PageMovable(struct page *page); |
58 | extern void __SetPageMovable(struct page *page, struct address_space *mapping); | |
59 | extern void __ClearPageMovable(struct page *page); | |
76ab0f53 MG |
60 | extern int sysctl_compact_memory; |
61 | extern int sysctl_compaction_handler(struct ctl_table *table, int write, | |
62 | void __user *buffer, size_t *length, loff_t *ppos); | |
5e771905 MG |
63 | extern int sysctl_extfrag_threshold; |
64 | extern int sysctl_extfrag_handler(struct ctl_table *table, int write, | |
65 | void __user *buffer, size_t *length, loff_t *ppos); | |
5bbe3547 | 66 | extern int sysctl_compact_unevictable_allowed; |
56de7263 MG |
67 | |
68 | extern int fragmentation_index(struct zone *zone, unsigned int order); | |
ea7ab982 MH |
69 | extern enum compact_result try_to_compact_pages(gfp_t gfp_mask, |
70 | unsigned int order, | |
c603844b MG |
71 | unsigned int alloc_flags, const struct alloc_context *ac, |
72 | enum migrate_mode mode, int *contended); | |
7103f16d | 73 | extern void compact_pgdat(pg_data_t *pgdat, int order); |
62997027 | 74 | extern void reset_isolation_suitable(pg_data_t *pgdat); |
ea7ab982 | 75 | extern enum compact_result compaction_suitable(struct zone *zone, int order, |
c603844b | 76 | unsigned int alloc_flags, int classzone_idx); |
4f92e258 | 77 | |
24e2716f JK |
78 | extern void defer_compaction(struct zone *zone, int order); |
79 | extern bool compaction_deferred(struct zone *zone, int order); | |
80 | extern void compaction_defer_reset(struct zone *zone, int order, | |
81 | bool alloc_success); | |
82 | extern bool compaction_restarting(struct zone *zone, int order); | |
62997027 | 83 | |
cab1802b MH |
84 | /* Compaction has made some progress and retrying makes sense */ |
85 | static inline bool compaction_made_progress(enum compact_result result) | |
86 | { | |
87 | /* | |
88 | * Even though this might sound confusing this in fact tells us | |
89 | * that the compaction successfully isolated and migrated some | |
90 | * pageblocks. | |
91 | */ | |
92 | if (result == COMPACT_PARTIAL) | |
93 | return true; | |
94 | ||
95 | return false; | |
96 | } | |
97 | ||
98 | /* Compaction has failed and it doesn't make much sense to keep retrying. */ | |
99 | static inline bool compaction_failed(enum compact_result result) | |
100 | { | |
101 | /* All zones were scanned completely and still not result. */ | |
102 | if (result == COMPACT_COMPLETE) | |
103 | return true; | |
104 | ||
105 | return false; | |
106 | } | |
107 | ||
108 | /* | |
109 | * Compaction has backed off for some reason. It might be throttling or | |
110 | * lock contention. Retrying is still worthwhile. | |
111 | */ | |
112 | static inline bool compaction_withdrawn(enum compact_result result) | |
113 | { | |
114 | /* | |
115 | * Compaction backed off due to watermark checks for order-0 | |
116 | * so the regular reclaim has to try harder and reclaim something. | |
117 | */ | |
118 | if (result == COMPACT_SKIPPED) | |
119 | return true; | |
120 | ||
121 | /* | |
122 | * If compaction is deferred for high-order allocations, it is | |
123 | * because sync compaction recently failed. If this is the case | |
124 | * and the caller requested a THP allocation, we do not want | |
125 | * to heavily disrupt the system, so we fail the allocation | |
126 | * instead of entering direct reclaim. | |
127 | */ | |
128 | if (result == COMPACT_DEFERRED) | |
129 | return true; | |
130 | ||
131 | /* | |
132 | * If compaction in async mode encounters contention or blocks higher | |
133 | * priority task we back off early rather than cause stalls. | |
134 | */ | |
135 | if (result == COMPACT_CONTENDED) | |
136 | return true; | |
137 | ||
138 | /* | |
139 | * Page scanners have met but we haven't scanned full zones so this | |
140 | * is a back off in fact. | |
141 | */ | |
142 | if (result == COMPACT_PARTIAL_SKIPPED) | |
143 | return true; | |
144 | ||
145 | return false; | |
146 | } | |
147 | ||
86a294a8 MH |
148 | |
149 | bool compaction_zonelist_suitable(struct alloc_context *ac, int order, | |
150 | int alloc_flags); | |
151 | ||
698b1b30 VB |
152 | extern int kcompactd_run(int nid); |
153 | extern void kcompactd_stop(int nid); | |
154 | extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx); | |
155 | ||
56de7263 | 156 | #else |
bda807d4 MK |
157 | static inline int PageMovable(struct page *page) |
158 | { | |
159 | return 0; | |
160 | } | |
161 | static inline void __SetPageMovable(struct page *page, | |
162 | struct address_space *mapping) | |
163 | { | |
164 | } | |
165 | ||
166 | static inline void __ClearPageMovable(struct page *page) | |
167 | { | |
168 | } | |
169 | ||
ea7ab982 | 170 | static inline enum compact_result try_to_compact_pages(gfp_t gfp_mask, |
1a6d53a1 VB |
171 | unsigned int order, int alloc_flags, |
172 | const struct alloc_context *ac, | |
173 | enum migrate_mode mode, int *contended) | |
56de7263 MG |
174 | { |
175 | return COMPACT_CONTINUE; | |
176 | } | |
177 | ||
7103f16d | 178 | static inline void compact_pgdat(pg_data_t *pgdat, int order) |
7be62de9 | 179 | { |
7be62de9 RR |
180 | } |
181 | ||
62997027 MG |
182 | static inline void reset_isolation_suitable(pg_data_t *pgdat) |
183 | { | |
184 | } | |
185 | ||
ea7ab982 | 186 | static inline enum compact_result compaction_suitable(struct zone *zone, int order, |
ebff3980 | 187 | int alloc_flags, int classzone_idx) |
3e7d3449 MG |
188 | { |
189 | return COMPACT_SKIPPED; | |
190 | } | |
191 | ||
aff62249 | 192 | static inline void defer_compaction(struct zone *zone, int order) |
4f92e258 MG |
193 | { |
194 | } | |
195 | ||
aff62249 | 196 | static inline bool compaction_deferred(struct zone *zone, int order) |
4f92e258 | 197 | { |
c59e2610 | 198 | return true; |
4f92e258 MG |
199 | } |
200 | ||
cab1802b MH |
201 | static inline bool compaction_made_progress(enum compact_result result) |
202 | { | |
203 | return false; | |
204 | } | |
205 | ||
206 | static inline bool compaction_failed(enum compact_result result) | |
207 | { | |
208 | return false; | |
209 | } | |
210 | ||
211 | static inline bool compaction_withdrawn(enum compact_result result) | |
212 | { | |
213 | return true; | |
214 | } | |
215 | ||
698b1b30 VB |
216 | static inline int kcompactd_run(int nid) |
217 | { | |
218 | return 0; | |
219 | } | |
220 | static inline void kcompactd_stop(int nid) | |
221 | { | |
222 | } | |
223 | ||
224 | static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx) | |
225 | { | |
226 | } | |
227 | ||
76ab0f53 MG |
228 | #endif /* CONFIG_COMPACTION */ |
229 | ||
ed4a6d7f | 230 | #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) |
bda807d4 | 231 | struct node; |
ed4a6d7f MG |
232 | extern int compaction_register_node(struct node *node); |
233 | extern void compaction_unregister_node(struct node *node); | |
234 | ||
235 | #else | |
236 | ||
237 | static inline int compaction_register_node(struct node *node) | |
238 | { | |
239 | return 0; | |
240 | } | |
241 | ||
242 | static inline void compaction_unregister_node(struct node *node) | |
243 | { | |
244 | } | |
245 | #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */ | |
246 | ||
748446bb | 247 | #endif /* _LINUX_COMPACTION_H */ |