| #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_COMPACTION |
| extern 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, bool *contended); |
| extern int compact_pgdat(pg_data_t *pgdat, int order); |
| 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, int order) |
| { |
| zone->compact_considered = 0; |
| zone->compact_defer_shift++; |
| |
| if (order < zone->compact_order_failed) |
| zone->compact_order_failed = order; |
| |
| 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, int order) |
| { |
| unsigned long defer_limit = 1UL << zone->compact_defer_shift; |
| |
| if (order < zone->compact_order_failed) |
| return false; |
| |
| /* Avoid possible overflow */ |
| if (++zone->compact_considered > defer_limit) |
| zone->compact_considered = defer_limit; |
| |
| return zone->compact_considered < (1UL << zone->compact_defer_shift); |
| } |
| |
| #else |
| static inline unsigned long try_to_compact_pages(struct zonelist *zonelist, |
| int order, gfp_t gfp_mask, nodemask_t *nodemask, |
| bool sync, bool *contended) |
| { |
| return COMPACT_CONTINUE; |
| } |
| |
| static inline int compact_pgdat(pg_data_t *pgdat, int order) |
| { |
| 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, int order) |
| { |
| } |
| |
| static inline bool compaction_deferred(struct zone *zone, int order) |
| { |
| 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 */ |