Commit | Line | Data |
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748446bb MG |
1 | #ifndef _LINUX_COMPACTION_H |
2 | #define _LINUX_COMPACTION_H | |
3 | ||
a5508cd8 VB |
4 | /* |
5 | * Determines how hard direct compaction should try to succeed. | |
6 | * Lower value means higher priority, analogically to reclaim priority. | |
7 | */ | |
8 | enum compact_priority { | |
9 | COMPACT_PRIO_SYNC_LIGHT, | |
10 | MIN_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT, | |
11 | DEF_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT, | |
12 | COMPACT_PRIO_ASYNC, | |
13 | INIT_COMPACT_PRIORITY = COMPACT_PRIO_ASYNC | |
14 | }; | |
15 | ||
56de7263 | 16 | /* Return values for compact_zone() and try_to_compact_pages() */ |
fa6c7b46 | 17 | /* When adding new states, please adjust include/trace/events/compaction.h */ |
ea7ab982 | 18 | enum compact_result { |
4f9a358c MH |
19 | /* For more detailed tracepoint output - internal to compaction */ |
20 | COMPACT_NOT_SUITABLE_ZONE, | |
ea7ab982 MH |
21 | /* |
22 | * compaction didn't start as it was not possible or direct reclaim | |
23 | * was more suitable | |
24 | */ | |
25 | COMPACT_SKIPPED, | |
1d4746d3 MH |
26 | /* compaction didn't start as it was deferred due to past failures */ |
27 | COMPACT_DEFERRED, | |
4f9a358c | 28 | |
1d4746d3 MH |
29 | /* compaction not active last round */ |
30 | COMPACT_INACTIVE = COMPACT_DEFERRED, | |
31 | ||
4f9a358c MH |
32 | /* For more detailed tracepoint output - internal to compaction */ |
33 | COMPACT_NO_SUITABLE_PAGE, | |
ea7ab982 MH |
34 | /* compaction should continue to another pageblock */ |
35 | COMPACT_CONTINUE, | |
4f9a358c | 36 | |
ea7ab982 | 37 | /* |
4f9a358c MH |
38 | * The full zone was compacted scanned but wasn't successfull to compact |
39 | * suitable pages. | |
ea7ab982 | 40 | */ |
4f9a358c | 41 | COMPACT_COMPLETE, |
c8f7de0b MH |
42 | /* |
43 | * direct compaction has scanned part of the zone but wasn't successfull | |
44 | * to compact suitable pages. | |
45 | */ | |
46 | COMPACT_PARTIAL_SKIPPED, | |
4f9a358c MH |
47 | |
48 | /* compaction terminated prematurely due to lock contentions */ | |
49 | COMPACT_CONTENDED, | |
50 | ||
c8f7de0b | 51 | /* |
4f9a358c MH |
52 | * direct compaction partially compacted a zone and there might be |
53 | * suitable pages | |
c8f7de0b | 54 | */ |
4f9a358c | 55 | COMPACT_PARTIAL, |
ea7ab982 | 56 | }; |
748446bb | 57 | |
1a6d53a1 VB |
58 | struct alloc_context; /* in mm/internal.h */ |
59 | ||
76ab0f53 MG |
60 | #ifdef CONFIG_COMPACTION |
61 | extern int sysctl_compact_memory; | |
62 | extern int sysctl_compaction_handler(struct ctl_table *table, int write, | |
63 | void __user *buffer, size_t *length, loff_t *ppos); | |
5e771905 MG |
64 | extern int sysctl_extfrag_threshold; |
65 | extern int sysctl_extfrag_handler(struct ctl_table *table, int write, | |
66 | void __user *buffer, size_t *length, loff_t *ppos); | |
5bbe3547 | 67 | extern int sysctl_compact_unevictable_allowed; |
56de7263 MG |
68 | |
69 | extern int fragmentation_index(struct zone *zone, unsigned int order); | |
ea7ab982 | 70 | extern enum compact_result try_to_compact_pages(gfp_t gfp_mask, |
c3486f53 VB |
71 | unsigned int order, unsigned int alloc_flags, |
72 | const struct alloc_context *ac, enum compact_priority prio); | |
62997027 | 73 | extern void reset_isolation_suitable(pg_data_t *pgdat); |
ea7ab982 | 74 | extern enum compact_result compaction_suitable(struct zone *zone, int order, |
c603844b | 75 | unsigned int alloc_flags, int classzone_idx); |
4f92e258 | 76 | |
24e2716f JK |
77 | extern void defer_compaction(struct zone *zone, int order); |
78 | extern bool compaction_deferred(struct zone *zone, int order); | |
79 | extern void compaction_defer_reset(struct zone *zone, int order, | |
80 | bool alloc_success); | |
81 | extern bool compaction_restarting(struct zone *zone, int order); | |
62997027 | 82 | |
cab1802b MH |
83 | /* Compaction has made some progress and retrying makes sense */ |
84 | static inline bool compaction_made_progress(enum compact_result result) | |
85 | { | |
86 | /* | |
87 | * Even though this might sound confusing this in fact tells us | |
88 | * that the compaction successfully isolated and migrated some | |
89 | * pageblocks. | |
90 | */ | |
91 | if (result == COMPACT_PARTIAL) | |
92 | return true; | |
93 | ||
94 | return false; | |
95 | } | |
96 | ||
97 | /* Compaction has failed and it doesn't make much sense to keep retrying. */ | |
98 | static inline bool compaction_failed(enum compact_result result) | |
99 | { | |
100 | /* All zones were scanned completely and still not result. */ | |
101 | if (result == COMPACT_COMPLETE) | |
102 | return true; | |
103 | ||
104 | return false; | |
105 | } | |
106 | ||
107 | /* | |
108 | * Compaction has backed off for some reason. It might be throttling or | |
109 | * lock contention. Retrying is still worthwhile. | |
110 | */ | |
111 | static inline bool compaction_withdrawn(enum compact_result result) | |
112 | { | |
113 | /* | |
114 | * Compaction backed off due to watermark checks for order-0 | |
115 | * so the regular reclaim has to try harder and reclaim something. | |
116 | */ | |
117 | if (result == COMPACT_SKIPPED) | |
118 | return true; | |
119 | ||
120 | /* | |
121 | * If compaction is deferred for high-order allocations, it is | |
122 | * because sync compaction recently failed. If this is the case | |
123 | * and the caller requested a THP allocation, we do not want | |
124 | * to heavily disrupt the system, so we fail the allocation | |
125 | * instead of entering direct reclaim. | |
126 | */ | |
127 | if (result == COMPACT_DEFERRED) | |
128 | return true; | |
129 | ||
130 | /* | |
131 | * If compaction in async mode encounters contention or blocks higher | |
132 | * priority task we back off early rather than cause stalls. | |
133 | */ | |
134 | if (result == COMPACT_CONTENDED) | |
135 | return true; | |
136 | ||
137 | /* | |
138 | * Page scanners have met but we haven't scanned full zones so this | |
139 | * is a back off in fact. | |
140 | */ | |
141 | if (result == COMPACT_PARTIAL_SKIPPED) | |
142 | return true; | |
143 | ||
144 | return false; | |
145 | } | |
146 | ||
86a294a8 MH |
147 | |
148 | bool compaction_zonelist_suitable(struct alloc_context *ac, int order, | |
149 | int alloc_flags); | |
150 | ||
698b1b30 VB |
151 | extern int kcompactd_run(int nid); |
152 | extern void kcompactd_stop(int nid); | |
153 | extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx); | |
154 | ||
56de7263 | 155 | #else |
62997027 MG |
156 | static inline void reset_isolation_suitable(pg_data_t *pgdat) |
157 | { | |
158 | } | |
159 | ||
ea7ab982 | 160 | static inline enum compact_result compaction_suitable(struct zone *zone, int order, |
ebff3980 | 161 | int alloc_flags, int classzone_idx) |
3e7d3449 MG |
162 | { |
163 | return COMPACT_SKIPPED; | |
164 | } | |
165 | ||
aff62249 | 166 | static inline void defer_compaction(struct zone *zone, int order) |
4f92e258 MG |
167 | { |
168 | } | |
169 | ||
aff62249 | 170 | static inline bool compaction_deferred(struct zone *zone, int order) |
4f92e258 | 171 | { |
c59e2610 | 172 | return true; |
4f92e258 MG |
173 | } |
174 | ||
cab1802b MH |
175 | static inline bool compaction_made_progress(enum compact_result result) |
176 | { | |
177 | return false; | |
178 | } | |
179 | ||
180 | static inline bool compaction_failed(enum compact_result result) | |
181 | { | |
182 | return false; | |
183 | } | |
184 | ||
185 | static inline bool compaction_withdrawn(enum compact_result result) | |
186 | { | |
187 | return true; | |
188 | } | |
189 | ||
698b1b30 VB |
190 | static inline int kcompactd_run(int nid) |
191 | { | |
192 | return 0; | |
193 | } | |
194 | static inline void kcompactd_stop(int nid) | |
195 | { | |
196 | } | |
197 | ||
198 | static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx) | |
199 | { | |
200 | } | |
201 | ||
76ab0f53 MG |
202 | #endif /* CONFIG_COMPACTION */ |
203 | ||
ed4a6d7f | 204 | #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) |
bda807d4 | 205 | struct node; |
ed4a6d7f MG |
206 | extern int compaction_register_node(struct node *node); |
207 | extern void compaction_unregister_node(struct node *node); | |
208 | ||
209 | #else | |
210 | ||
211 | static inline int compaction_register_node(struct node *node) | |
212 | { | |
213 | return 0; | |
214 | } | |
215 | ||
216 | static inline void compaction_unregister_node(struct node *node) | |
217 | { | |
218 | } | |
219 | #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */ | |
220 | ||
748446bb | 221 | #endif /* _LINUX_COMPACTION_H */ |