blob: ef658147e4e8391eec61aa7559a1452fcffe6a79 [file] [log] [blame]
Mel Gorman748446b2010-05-24 14:32:27 -07001#ifndef _LINUX_COMPACTION_H
2#define _LINUX_COMPACTION_H
3
Mel Gorman56de7262010-05-24 14:32:30 -07004/* Return values for compact_zone() and try_to_compact_pages() */
5/* compaction didn't start as it was not possible or direct reclaim was more suitable */
6#define COMPACT_SKIPPED 0
7/* compaction should continue to another pageblock */
8#define COMPACT_CONTINUE 1
9/* direct compaction partially compacted a zone and there are suitable pages */
10#define COMPACT_PARTIAL 2
11/* The full zone was compacted */
12#define COMPACT_COMPLETE 3
Mel Gorman748446b2010-05-24 14:32:27 -070013
Mel Gorman76ab0f52010-05-24 14:32:28 -070014#ifdef CONFIG_COMPACTION
15extern int sysctl_compact_memory;
16extern int sysctl_compaction_handler(struct ctl_table *table, int write,
17 void __user *buffer, size_t *length, loff_t *ppos);
Mel Gorman5e771902010-05-24 14:32:31 -070018extern int sysctl_extfrag_threshold;
19extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
20 void __user *buffer, size_t *length, loff_t *ppos);
Mel Gorman56de7262010-05-24 14:32:30 -070021
22extern int fragmentation_index(struct zone *zone, unsigned int order);
23extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
Mel Gorman77f1fe62011-01-13 15:45:57 -080024 int order, gfp_t gfp_mask, nodemask_t *mask,
Mel Gormanc67fe372012-08-21 16:16:17 -070025 bool sync, bool *contended);
Rik van Riel7be62de2012-03-21 16:33:52 -070026extern int compact_pgdat(pg_data_t *pgdat, int order);
Mel Gorman3e7d3442011-01-13 15:45:56 -080027extern unsigned long compaction_suitable(struct zone *zone, int order);
Mel Gorman4f92e252010-05-24 14:32:32 -070028
29/* Do not skip compaction more than 64 times */
30#define COMPACT_MAX_DEFER_SHIFT 6
31
32/*
33 * Compaction is deferred when compaction fails to result in a page
34 * allocation success. 1 << compact_defer_limit compactions are skipped up
35 * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
36 */
Rik van Rielaff62242012-03-21 16:33:52 -070037static inline void defer_compaction(struct zone *zone, int order)
Mel Gorman4f92e252010-05-24 14:32:32 -070038{
39 zone->compact_considered = 0;
40 zone->compact_defer_shift++;
41
Rik van Rielaff62242012-03-21 16:33:52 -070042 if (order < zone->compact_order_failed)
43 zone->compact_order_failed = order;
44
Mel Gorman4f92e252010-05-24 14:32:32 -070045 if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
46 zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
47}
48
49/* Returns true if compaction should be skipped this time */
Rik van Rielaff62242012-03-21 16:33:52 -070050static inline bool compaction_deferred(struct zone *zone, int order)
Mel Gorman4f92e252010-05-24 14:32:32 -070051{
52 unsigned long defer_limit = 1UL << zone->compact_defer_shift;
53
Rik van Rielaff62242012-03-21 16:33:52 -070054 if (order < zone->compact_order_failed)
55 return false;
56
Mel Gorman4f92e252010-05-24 14:32:32 -070057 /* Avoid possible overflow */
58 if (++zone->compact_considered > defer_limit)
59 zone->compact_considered = defer_limit;
60
Gavin Shanc59e2612012-07-31 16:42:49 -070061 return zone->compact_considered < defer_limit;
Mel Gorman4f92e252010-05-24 14:32:32 -070062}
63
Mel Gorman56de7262010-05-24 14:32:30 -070064#else
65static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
Mel Gorman77f1fe62011-01-13 15:45:57 -080066 int order, gfp_t gfp_mask, nodemask_t *nodemask,
Mel Gormanc67fe372012-08-21 16:16:17 -070067 bool sync, bool *contended)
Mel Gorman56de7262010-05-24 14:32:30 -070068{
69 return COMPACT_CONTINUE;
70}
71
Rik van Riel7be62de2012-03-21 16:33:52 -070072static inline int compact_pgdat(pg_data_t *pgdat, int order)
73{
74 return COMPACT_CONTINUE;
75}
76
Mel Gorman3e7d3442011-01-13 15:45:56 -080077static inline unsigned long compaction_suitable(struct zone *zone, int order)
78{
79 return COMPACT_SKIPPED;
80}
81
Rik van Rielaff62242012-03-21 16:33:52 -070082static inline void defer_compaction(struct zone *zone, int order)
Mel Gorman4f92e252010-05-24 14:32:32 -070083{
84}
85
Rik van Rielaff62242012-03-21 16:33:52 -070086static inline bool compaction_deferred(struct zone *zone, int order)
Mel Gorman4f92e252010-05-24 14:32:32 -070087{
Gavin Shanc59e2612012-07-31 16:42:49 -070088 return true;
Mel Gorman4f92e252010-05-24 14:32:32 -070089}
90
Mel Gorman76ab0f52010-05-24 14:32:28 -070091#endif /* CONFIG_COMPACTION */
92
Mel Gormaned4a6d72010-05-24 14:32:29 -070093#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
94extern int compaction_register_node(struct node *node);
95extern void compaction_unregister_node(struct node *node);
96
97#else
98
99static inline int compaction_register_node(struct node *node)
100{
101 return 0;
102}
103
104static inline void compaction_unregister_node(struct node *node)
105{
106}
107#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
108
Mel Gorman748446b2010-05-24 14:32:27 -0700109#endif /* _LINUX_COMPACTION_H */