LXR linux/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#define COMPACT_CONTENDED               7
  19/* When adding new states, please adjust include/trace/events/compaction.h */
  20
  21/* Used to signal whether compaction detected need_sched() or lock contention */
  22/* No contention detected */
  23#define COMPACT_CONTENDED_NONE  0
  24/* Either need_sched() was true or fatal signal pending */
  25#define COMPACT_CONTENDED_SCHED 1
  26/* Zone lock or lru_lock was contended in async compaction */
  27#define COMPACT_CONTENDED_LOCK  2
  28
  29struct alloc_context; /* in mm/internal.h */
  30
  31#ifdef CONFIG_COMPACTION
  32extern int sysctl_compact_memory;
  33extern int sysctl_compaction_handler(struct ctl_table *table, int write,
  34                        void __user *buffer, size_t *length, loff_t *ppos);
  35extern int sysctl_extfrag_threshold;
  36extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
  37                        void __user *buffer, size_t *length, loff_t *ppos);
  38extern int sysctl_compact_unevictable_allowed;
  39
  40extern int fragmentation_index(struct zone *zone, unsigned int order);
  41extern unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
  42                        int alloc_flags, const struct alloc_context *ac,
  43                        enum migrate_mode mode, int *contended);
  44extern void compact_pgdat(pg_data_t *pgdat, int order);
  45extern void reset_isolation_suitable(pg_data_t *pgdat);
  46extern unsigned long compaction_suitable(struct zone *zone, int order,
  47                                        int alloc_flags, int classzone_idx);
  48
  49extern void defer_compaction(struct zone *zone, int order);
  50extern bool compaction_deferred(struct zone *zone, int order);
  51extern void compaction_defer_reset(struct zone *zone, int order,
  52                                bool alloc_success);
  53extern bool compaction_restarting(struct zone *zone, int order);
  54
  55extern int kcompactd_run(int nid);
  56extern void kcompactd_stop(int nid);
  57extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
  58
  59#else
  60static inline unsigned long try_to_compact_pages(gfp_t gfp_mask,
  61                        unsigned int order, int alloc_flags,
  62                        const struct alloc_context *ac,
  63                        enum migrate_mode mode, int *contended)
  64{
  65        return COMPACT_CONTINUE;
  66}
  67
  68static inline void compact_pgdat(pg_data_t *pgdat, int order)
  69{
  70}
  71
  72static inline void reset_isolation_suitable(pg_data_t *pgdat)
  73{
  74}
  75
  76static inline unsigned long compaction_suitable(struct zone *zone, int order,
  77                                        int alloc_flags, int classzone_idx)
  78{
  79        return COMPACT_SKIPPED;
  80}
  81
  82static inline void defer_compaction(struct zone *zone, int order)
  83{
  84}
  85
  86static inline bool compaction_deferred(struct zone *zone, int order)
  87{
  88        return true;
  89}
  90
  91static inline int kcompactd_run(int nid)
  92{
  93        return 0;
  94}
  95static inline void kcompactd_stop(int nid)
  96{
  97}
  98
  99static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
 100{
 101}
 102
 103#endif /* CONFIG_COMPACTION */
 104
 105#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
 106extern int compaction_register_node(struct node *node);
 107extern void compaction_unregister_node(struct node *node);
 108
 109#else
 110
 111static inline int compaction_register_node(struct node *node)
 112{
 113        return 0;
 114}
 115
 116static inline void compaction_unregister_node(struct node *node)
 117{
 118}
 119#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
 120
 121#endif /* _LINUX_COMPACTION_H */
 122