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 /* compaction didn't start as it was deferred due to past failures */
   6 #define COMPACT_DEFERRED        0
   7 /* compaction didn't start as it was not possible or direct reclaim was more suitable */
   8 #define COMPACT_SKIPPED         1
   9 /* compaction should continue to another pageblock */
  10 #define COMPACT_CONTINUE        2
  11 /* direct compaction partially compacted a zone and there are suitable pages */
  12 #define COMPACT_PARTIAL         3
  13 /* The full zone was compacted */
  14 #define COMPACT_COMPLETE        4
  15 /* For more detailed tracepoint output */
  16 #define COMPACT_NO_SUITABLE_PAGE        5
  17 #define COMPACT_NOT_SUITABLE_ZONE       6
  18 /* When adding new state, please change compaction_status_string, too */
  19
  20 /* Used to signal whether compaction detected need_sched() or lock contention */
  21 /* No contention detected */
  22 #define COMPACT_CONTENDED_NONE  0
  23 /* Either need_sched() was true or fatal signal pending */
  24 #define COMPACT_CONTENDED_SCHED 1
  25 /* Zone lock or lru_lock was contended in async compaction */
  26 #define COMPACT_CONTENDED_LOCK  2
  27
  28 struct alloc_context; /* in mm/internal.h */
  29
  30 #ifdef CONFIG_COMPACTION
  31 extern int sysctl_compact_memory;
  32 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
  33                         void __user *buffer, size_t *length, loff_t *ppos);
  34 extern int sysctl_extfrag_threshold;
  35 extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
  36                         void __user *buffer, size_t *length, loff_t *ppos);
  37
  38 extern int fragmentation_index(struct zone *zone, unsigned int order);
  39 extern unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
  40                         int alloc_flags, const struct alloc_context *ac,
  41                         enum migrate_mode mode, int *contended);
  42 extern void compact_pgdat(pg_data_t *pgdat, int order);
  43 extern void reset_isolation_suitable(pg_data_t *pgdat);
  44 extern unsigned long compaction_suitable(struct zone *zone, int order,
  45                                         int alloc_flags, int classzone_idx);
  46
  47 extern void defer_compaction(struct zone *zone, int order);
  48 extern bool compaction_deferred(struct zone *zone, int order);
  49 extern void compaction_defer_reset(struct zone *zone, int order,
  50                                 bool alloc_success);
  51 extern bool compaction_restarting(struct zone *zone, int order);
  52
  53 #else
  54 static inline unsigned long try_to_compact_pages(gfp_t gfp_mask,
  55                         unsigned int order, int alloc_flags,
  56                         const struct alloc_context *ac,
  57                         enum migrate_mode mode, int *contended)
  58 {
  59         return COMPACT_CONTINUE;
  60 }
  61
  62 static inline void compact_pgdat(pg_data_t *pgdat, int order)
  63 {
  64 }
  65
  66 static inline void reset_isolation_suitable(pg_data_t *pgdat)
  67 {
  68 }
  69
  70 static inline unsigned long compaction_suitable(struct zone *zone, int order,
  71                                         int alloc_flags, int classzone_idx)
  72 {
  73         return COMPACT_SKIPPED;
  74 }
  75
  76 static inline void defer_compaction(struct zone *zone, int order)
  77 {
  78 }
  79
  80 static inline bool compaction_deferred(struct zone *zone, int order)
  81 {
  82         return true;
  83 }
  84
  85 #endif /* CONFIG_COMPACTION */
  86
  87 #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
  88 extern int compaction_register_node(struct node *node);
  89 extern void compaction_unregister_node(struct node *node);
  90
  91 #else
  92
  93 static inline int compaction_register_node(struct node *node)
  94 {
  95         return 0;
  96 }
  97
  98 static inline void compaction_unregister_node(struct node *node)
  99 {
 100 }
 101 #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
 102
 103 #endif /* _LINUX_COMPACTION_H */