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