#ifndef _LINUX_COMPACTION_H#define _LINUX_COMPACTION_H /* Return values for compact_zone() and try_to_compact_pages() *//* compaction didn't start as it was not possible or direct reclaim was more suitable */#define COMPACT_SKIPPED		0/* compaction should continue to another pageblock */#define COMPACT_CONTINUE	1/* direct compaction partially compacted a zone and there are suitable pages */#define COMPACT_PARTIAL		2/* The full zone was compacted */#define COMPACT_COMPLETE	3 #ifdef CONFIG_COMPACTIONextern int sysctl_compact_memory;extern int sysctl_compaction_handler(struct ctl_table *table, int write,			void __user *buffer, size_t *length, loff_t *ppos);extern int sysctl_extfrag_threshold;extern int sysctl_extfrag_handler(struct ctl_table *table, int write,			void __user *buffer, size_t *length, loff_t *ppos); extern int fragmentation_index(struct zone *zone, unsigned int order);extern unsigned long try_to_compact_pages(struct zonelist *zonelist,			int order, gfp_t gfp_mask, nodemask_t *mask,			bool sync);extern unsigned long compaction_suitable(struct zone *zone, int order); /* Do not skip compaction more than 64 times */#define COMPACT_MAX_DEFER_SHIFT 6 /* * Compaction is deferred when compaction fails to result in a page * allocation success. 1 << compact_defer_limit compactions are skipped up * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT */static inline void defer_compaction(struct zone *zone){	zone->compact_considered = 0;	zone->compact_defer_shift++; 	if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)		zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;} /* Returns true if compaction should be skipped this time */static inline bool compaction_deferred(struct zone *zone){	unsigned long defer_limit = 1UL << zone->compact_defer_shift; 	/* Avoid possible overflow */	if (++zone->compact_considered > defer_limit)		zone->compact_considered = defer_limit; 	return zone->compact_considered < (1UL << zone->compact_defer_shift);} #elsestatic inline unsigned long try_to_compact_pages(struct zonelist *zonelist,			int order, gfp_t gfp_mask, nodemask_t *nodemask,			bool sync){	return COMPACT_CONTINUE;} static inline unsigned long compaction_suitable(struct zone *zone, int order){	return COMPACT_SKIPPED;} static inline void defer_compaction(struct zone *zone){} static inline bool compaction_deferred(struct zone *zone){	return 1;} #endif /* CONFIG_COMPACTION */ #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)extern int compaction_register_node(struct node *node);extern void compaction_unregister_node(struct node *node); #else static inline int compaction_register_node(struct node *node){	return 0;} static inline void compaction_unregister_node(struct node *node){}#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */ #endif /* _LINUX_COMPACTION_H */