include/linux/compaction.h

   1 #ifndef _LINUX_COMPACTION_H
   2 #define _LINUX_COMPACTION_H
   3
   4 /* Return values for compact_zone() and try_to_compact_pages() */
   5 /* When adding new states, please adjust include/trace/events/compaction.h */
   6 enum compact_result {
   7         /*
   8          * compaction didn't start as it was not possible or direct reclaim
   9          * was more suitable
  10          */
  11         COMPACT_SKIPPED,
  12         /* compaction didn't start as it was deferred due to past failures */
  13         COMPACT_DEFERRED,
  14         /* compaction not active last round */
  15         COMPACT_INACTIVE = COMPACT_DEFERRED,
  16
  17         /* compaction should continue to another pageblock */
  18         COMPACT_CONTINUE,
  19         /*
  20          * direct compaction partially compacted a zone and there are suitable
  21          * pages
  22          */
  23         COMPACT_PARTIAL,
  24         /*
  25          * direct compaction has scanned part of the zone but wasn't successfull
  26          * to compact suitable pages.
  27          */
  28         COMPACT_PARTIAL_SKIPPED,
  29         /*
  30          * The full zone was compacted scanned but wasn't successfull to compact
  31          * suitable pages.
  32          */
  33         COMPACT_COMPLETE,
  34         /* For more detailed tracepoint output */
  35         COMPACT_NO_SUITABLE_PAGE,
  36         COMPACT_NOT_SUITABLE_ZONE,
  37         COMPACT_CONTENDED,
  38 };
  39
  40 /* Used to signal whether compaction detected need_sched() or lock contention */
  41 /* No contention detected */
  42 #define COMPACT_CONTENDED_NONE  0
  43 /* Either need_sched() was true or fatal signal pending */
  44 #define COMPACT_CONTENDED_SCHED 1
  45 /* Zone lock or lru_lock was contended in async compaction */
  46 #define COMPACT_CONTENDED_LOCK  2
  47
  48 struct alloc_context; /* in mm/internal.h */
  49
  50 #ifdef CONFIG_COMPACTION
  51 extern int sysctl_compact_memory;
  52 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
  53                         void __user *buffer, size_t *length, loff_t *ppos);
  54 extern int sysctl_extfrag_threshold;
  55 extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
  56                         void __user *buffer, size_t *length, loff_t *ppos);
  57 extern int sysctl_compact_unevictable_allowed;
  58
  59 extern int fragmentation_index(struct zone *zone, unsigned int order);
  60 extern enum compact_result try_to_compact_pages(gfp_t gfp_mask,
  61                         unsigned int order,
  62                 unsigned int alloc_flags, const struct alloc_context *ac,
  63                 enum migrate_mode mode, int *contended);
  64 extern void compact_pgdat(pg_data_t *pgdat, int order);
  65 extern void reset_isolation_suitable(pg_data_t *pgdat);
  66 extern enum compact_result compaction_suitable(struct zone *zone, int order,
  67                 unsigned int alloc_flags, int classzone_idx);
  68
  69 extern void defer_compaction(struct zone *zone, int order);
  70 extern bool compaction_deferred(struct zone *zone, int order);
  71 extern void compaction_defer_reset(struct zone *zone, int order,
  72                                 bool alloc_success);
  73 extern bool compaction_restarting(struct zone *zone, int order);
  74
  75 extern int kcompactd_run(int nid);
  76 extern void kcompactd_stop(int nid);
  77 extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
  78
  79 #else
  80 static inline enum compact_result try_to_compact_pages(gfp_t gfp_mask,
  81                         unsigned int order, int alloc_flags,
  82                         const struct alloc_context *ac,
  83                         enum migrate_mode mode, int *contended)
  84 {
  85         return COMPACT_CONTINUE;
  86 }
  87
  88 static inline void compact_pgdat(pg_data_t *pgdat, int order)
  89 {
  90 }
  91
  92 static inline void reset_isolation_suitable(pg_data_t *pgdat)
  93 {
  94 }
  95
  96 static inline enum compact_result compaction_suitable(struct zone *zone, int order,
  97                                         int alloc_flags, int classzone_idx)
  98 {
  99         return COMPACT_SKIPPED;
 100 }
 101
 102 static inline void defer_compaction(struct zone *zone, int order)
 103 {
 104 }
 105
 106 static inline bool compaction_deferred(struct zone *zone, int order)
 107 {
 108         return true;
 109 }
 110
 111 static inline int kcompactd_run(int nid)
 112 {
 113         return 0;
 114 }
 115 static inline void kcompactd_stop(int nid)
 116 {
 117 }
 118
 119 static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
 120 {
 121 }
 122
 123 #endif /* CONFIG_COMPACTION */
 124
 125 #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
 126 extern int compaction_register_node(struct node *node);
 127 extern void compaction_unregister_node(struct node *node);
 128
 129 #else
 130
 131 static inline int compaction_register_node(struct node *node)
 132 {
 133         return 0;
 134 }
 135
 136 static inline void compaction_unregister_node(struct node *node)
 137 {
 138 }
 139 #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
 140
 141 #endif /* _LINUX_COMPACTION_H */