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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
// SPDX-License-Identifier: GPL-3.0-or-later
#ifndef NETDATA_PAGECACHE_H
#define NETDATA_PAGECACHE_H
#include "rrdengine.h"
/* Forward declarations */
struct rrdengine_instance;
struct extent_info;
struct rrdeng_page_descr;
#define INVALID_TIME (0)
/* Page flags */
#define RRD_PAGE_DIRTY (1LU << 0)
#define RRD_PAGE_LOCKED (1LU << 1)
#define RRD_PAGE_READ_PENDING (1LU << 2)
#define RRD_PAGE_WRITE_PENDING (1LU << 3)
#define RRD_PAGE_POPULATED (1LU << 4)
struct page_cache_descr {
struct rrdeng_page_descr *descr; /* parent descriptor */
void *page;
unsigned long flags;
struct page_cache_descr *prev; /* LRU */
struct page_cache_descr *next; /* LRU */
unsigned refcnt;
uv_mutex_t mutex; /* always take it after the page cache lock or after the commit lock */
uv_cond_t cond;
unsigned waiters;
};
/* Page cache descriptor flags, state = 0 means no descriptor */
#define PG_CACHE_DESCR_ALLOCATED (1LU << 0)
#define PG_CACHE_DESCR_DESTROY (1LU << 1)
#define PG_CACHE_DESCR_LOCKED (1LU << 2)
#define PG_CACHE_DESCR_SHIFT (3)
#define PG_CACHE_DESCR_USERS_MASK (((unsigned long)-1) << PG_CACHE_DESCR_SHIFT)
#define PG_CACHE_DESCR_FLAGS_MASK (((unsigned long)-1) >> (BITS_PER_ULONG - PG_CACHE_DESCR_SHIFT))
/*
* Page cache descriptor state bits (works for both 32-bit and 64-bit architectures):
*
* 63 ... 31 ... 3 | 2 | 1 | 0|
* -----------------------------+------------+------------+-----------|
* number of descriptor users | DESTROY | LOCKED | ALLOCATED |
*/
struct rrdeng_page_descr {
uint32_t page_length;
usec_t start_time;
usec_t end_time;
uuid_t *id; /* never changes */
struct extent_info *extent;
/* points to ephemeral page cache descriptor if the page resides in the cache */
struct page_cache_descr *pg_cache_descr;
/* Compare-And-Swap target for page cache descriptor allocation algorithm */
volatile unsigned long pg_cache_descr_state;
};
#define PAGE_CACHE_MAX_PRELOAD_PAGES (256)
/* maps time ranges to pages */
struct pg_cache_page_index {
uuid_t id;
/*
* care: JudyL_array indices are converted from useconds to seconds to fit in one word in 32-bit architectures
* TODO: examine if we want to support better granularity than seconds
*/
Pvoid_t JudyL_array;
uv_rwlock_t lock;
/*
* Only one effective writer, data deletion workqueue.
* It's also written during the DB loading phase.
*/
usec_t oldest_time;
/*
* Only one effective writer, data collection thread.
* It's also written by the data deletion workqueue when data collection is disabled for this metric.
*/
usec_t latest_time;
struct pg_cache_page_index *prev;
};
/* maps UUIDs to page indices */
struct pg_cache_metrics_index {
uv_rwlock_t lock;
Pvoid_t JudyHS_array;
struct pg_cache_page_index *last_page_index;
};
/* gathers dirty pages to be written on disk */
struct pg_cache_commited_page_index {
uv_rwlock_t lock;
Pvoid_t JudyL_array;
/*
* Dirty page correlation ID is a hint. Dirty pages that are correlated should have
* a small correlation ID difference. Dirty pages in memory should never have the
* same ID at the same time for correctness.
*/
Word_t latest_corr_id;
unsigned nr_commited_pages;
};
/*
* Gathers populated pages to be evicted.
* Relies on page cache descriptors being there as it uses their memory.
*/
struct pg_cache_replaceQ {
uv_rwlock_t lock; /* LRU lock */
struct page_cache_descr *head; /* LRU */
struct page_cache_descr *tail; /* MRU */
};
struct page_cache { /* TODO: add statistics */
uv_rwlock_t pg_cache_rwlock; /* page cache lock */
struct pg_cache_metrics_index metrics_index;
struct pg_cache_commited_page_index commited_page_index;
struct pg_cache_replaceQ replaceQ;
unsigned page_descriptors;
unsigned populated_pages;
};
extern void pg_cache_wake_up_waiters_unsafe(struct rrdeng_page_descr *descr);
extern void pg_cache_wait_event_unsafe(struct rrdeng_page_descr *descr);
extern unsigned long pg_cache_wait_event(struct rrdengine_instance *ctx, struct rrdeng_page_descr *descr);
extern void pg_cache_replaceQ_insert(struct rrdengine_instance *ctx,
struct rrdeng_page_descr *descr);
extern void pg_cache_replaceQ_delete(struct rrdengine_instance *ctx,
struct rrdeng_page_descr *descr);
extern void pg_cache_replaceQ_set_hot(struct rrdengine_instance *ctx,
struct rrdeng_page_descr *descr);
extern struct rrdeng_page_descr *pg_cache_create_descr(void);
extern int pg_cache_try_get_unsafe(struct rrdeng_page_descr *descr, int exclusive_access);
extern void pg_cache_put_unsafe(struct rrdeng_page_descr *descr);
extern void pg_cache_put(struct rrdengine_instance *ctx, struct rrdeng_page_descr *descr);
extern void pg_cache_insert(struct rrdengine_instance *ctx, struct pg_cache_page_index *index,
struct rrdeng_page_descr *descr);
extern void pg_cache_punch_hole(struct rrdengine_instance *ctx, struct rrdeng_page_descr *descr, uint8_t remove_dirty);
extern struct pg_cache_page_index *
pg_cache_preload(struct rrdengine_instance *ctx, uuid_t *id, usec_t start_time, usec_t end_time);
extern struct rrdeng_page_descr *
pg_cache_lookup(struct rrdengine_instance *ctx, struct pg_cache_page_index *index, uuid_t *id,
usec_t point_in_time);
extern struct pg_cache_page_index *create_page_index(uuid_t *id);
extern void init_page_cache(struct rrdengine_instance *ctx);
extern void free_page_cache(struct rrdengine_instance *ctx);
extern void pg_cache_add_new_metric_time(struct pg_cache_page_index *page_index, struct rrdeng_page_descr *descr);
extern void pg_cache_update_metric_times(struct pg_cache_page_index *page_index);
#endif /* NETDATA_PAGECACHE_H */
|
