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 MG |
56 | #ifdef CONFIG_COMPACTION |
57 | extern int sysctl_compact_memory; | |
58 | extern int sysctl_compaction_handler(struct ctl_table *table, int write, | |
59 | void __user *buffer, size_t *length, loff_t *ppos); | |
5e771905 MG |
60 | extern int sysctl_extfrag_threshold; |
61 | extern int sysctl_extfrag_handler(struct ctl_table *table, int write, | |
62 | void __user *buffer, size_t *length, loff_t *ppos); | |
5bbe3547 | 63 | extern int sysctl_compact_unevictable_allowed; |
56de7263 MG |
64 | |
65 | extern int fragmentation_index(struct zone *zone, unsigned int order); | |
ea7ab982 MH |
66 | extern enum compact_result try_to_compact_pages(gfp_t gfp_mask, |
67 | unsigned int order, | |
c603844b MG |
68 | unsigned int alloc_flags, const struct alloc_context *ac, |
69 | enum migrate_mode mode, int *contended); | |
7103f16d | 70 | extern void compact_pgdat(pg_data_t *pgdat, int order); |
62997027 | 71 | extern void reset_isolation_suitable(pg_data_t *pgdat); |
ea7ab982 | 72 | extern enum compact_result compaction_suitable(struct zone *zone, int order, |
c603844b | 73 | unsigned int alloc_flags, int classzone_idx); |
4f92e258 | 74 | |
24e2716f JK |
75 | extern void defer_compaction(struct zone *zone, int order); |
76 | extern bool compaction_deferred(struct zone *zone, int order); | |
77 | extern void compaction_defer_reset(struct zone *zone, int order, | |
78 | bool alloc_success); | |
79 | extern bool compaction_restarting(struct zone *zone, int order); | |
62997027 | 80 | |
cab1802b MH |
81 | /* Compaction has made some progress and retrying makes sense */ |
82 | static inline bool compaction_made_progress(enum compact_result result) | |
83 | { | |
84 | /* | |
85 | * Even though this might sound confusing this in fact tells us | |
86 | * that the compaction successfully isolated and migrated some | |
87 | * pageblocks. | |
88 | */ | |
89 | if (result == COMPACT_PARTIAL) | |
90 | return true; | |
91 | ||
92 | return false; | |
93 | } | |
94 | ||
95 | /* Compaction has failed and it doesn't make much sense to keep retrying. */ | |
96 | static inline bool compaction_failed(enum compact_result result) | |
97 | { | |
98 | /* All zones were scanned completely and still not result. */ | |
99 | if (result == COMPACT_COMPLETE) | |
100 | return true; | |
101 | ||
102 | return false; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Compaction has backed off for some reason. It might be throttling or | |
107 | * lock contention. Retrying is still worthwhile. | |
108 | */ | |
109 | static inline bool compaction_withdrawn(enum compact_result result) | |
110 | { | |
111 | /* | |
112 | * Compaction backed off due to watermark checks for order-0 | |
113 | * so the regular reclaim has to try harder and reclaim something. | |
114 | */ | |
115 | if (result == COMPACT_SKIPPED) | |
116 | return true; | |
117 | ||
118 | /* | |
119 | * If compaction is deferred for high-order allocations, it is | |
120 | * because sync compaction recently failed. If this is the case | |
121 | * and the caller requested a THP allocation, we do not want | |
122 | * to heavily disrupt the system, so we fail the allocation | |
123 | * instead of entering direct reclaim. | |
124 | */ | |
125 | if (result == COMPACT_DEFERRED) | |
126 | return true; | |
127 | ||
128 | /* | |
129 | * If compaction in async mode encounters contention or blocks higher | |
130 | * priority task we back off early rather than cause stalls. | |
131 | */ | |
132 | if (result == COMPACT_CONTENDED) | |
133 | return true; | |
134 | ||
135 | /* | |
136 | * Page scanners have met but we haven't scanned full zones so this | |
137 | * is a back off in fact. | |
138 | */ | |
139 | if (result == COMPACT_PARTIAL_SKIPPED) | |
140 | return true; | |
141 | ||
142 | return false; | |
143 | } | |
144 | ||
86a294a8 MH |
145 | |
146 | bool compaction_zonelist_suitable(struct alloc_context *ac, int order, | |
147 | int alloc_flags); | |
148 | ||
698b1b30 VB |
149 | extern int kcompactd_run(int nid); |
150 | extern void kcompactd_stop(int nid); | |
151 | extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx); | |
152 | ||
56de7263 | 153 | #else |
ea7ab982 | 154 | static inline enum compact_result try_to_compact_pages(gfp_t gfp_mask, |
1a6d53a1 VB |
155 | unsigned int order, int alloc_flags, |
156 | const struct alloc_context *ac, | |
157 | enum migrate_mode mode, int *contended) | |
56de7263 MG |
158 | { |
159 | return COMPACT_CONTINUE; | |
160 | } | |
161 | ||
7103f16d | 162 | static inline void compact_pgdat(pg_data_t *pgdat, int order) |
7be62de9 | 163 | { |
7be62de9 RR |
164 | } |
165 | ||
62997027 MG |
166 | static inline void reset_isolation_suitable(pg_data_t *pgdat) |
167 | { | |
168 | } | |
169 | ||
ea7ab982 | 170 | static inline enum compact_result compaction_suitable(struct zone *zone, int order, |
ebff3980 | 171 | int alloc_flags, int classzone_idx) |
3e7d3449 MG |
172 | { |
173 | return COMPACT_SKIPPED; | |
174 | } | |
175 | ||
aff62249 | 176 | static inline void defer_compaction(struct zone *zone, int order) |
4f92e258 MG |
177 | { |
178 | } | |
179 | ||
aff62249 | 180 | static inline bool compaction_deferred(struct zone *zone, int order) |
4f92e258 | 181 | { |
c59e2610 | 182 | return true; |
4f92e258 MG |
183 | } |
184 | ||
cab1802b MH |
185 | static inline bool compaction_made_progress(enum compact_result result) |
186 | { | |
187 | return false; | |
188 | } | |
189 | ||
190 | static inline bool compaction_failed(enum compact_result result) | |
191 | { | |
192 | return false; | |
193 | } | |
194 | ||
195 | static inline bool compaction_withdrawn(enum compact_result result) | |
196 | { | |
197 | return true; | |
198 | } | |
199 | ||
698b1b30 VB |
200 | static inline int kcompactd_run(int nid) |
201 | { | |
202 | return 0; | |
203 | } | |
204 | static inline void kcompactd_stop(int nid) | |
205 | { | |
206 | } | |
207 | ||
208 | static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx) | |
209 | { | |
210 | } | |
211 | ||
76ab0f53 MG |
212 | #endif /* CONFIG_COMPACTION */ |
213 | ||
ed4a6d7f MG |
214 | #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) |
215 | extern int compaction_register_node(struct node *node); | |
216 | extern void compaction_unregister_node(struct node *node); | |
217 | ||
218 | #else | |
219 | ||
220 | static inline int compaction_register_node(struct node *node) | |
221 | { | |
222 | return 0; | |
223 | } | |
224 | ||
225 | static inline void compaction_unregister_node(struct node *node) | |
226 | { | |
227 | } | |
228 | #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */ | |
229 | ||
748446bb | 230 | #endif /* _LINUX_COMPACTION_H */ |