1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
#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 void reset_isolation_suitable(pg_data_t *pgdat);
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 < defer_limit;
}
/* Returns true if restarting compaction after many failures */
static inline bool compaction_restarting(struct zone *zone, int order)
{
if (order < zone->compact_order_failed)
return false;
return zone->compact_defer_shift == COMPACT_MAX_DEFER_SHIFT &&
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 void reset_isolation_suitable(pg_data_t *pgdat)
{
}
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 true;
}
#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 */
|
