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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*-
* Copyright (c) 2014-2016 MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
/*
* Tuning constants: I hesitate to call this tuning, but we want to review some
* number of pages from each file's in-memory tree for each page we evict.
*/
#define WT_EVICT_INT_SKEW (1<<20) /* Prefer leaf pages over internal
pages by this many increments of the
read generation. */
#define WT_EVICT_WALK_BASE 300 /* Pages tracked across file visits */
#define WT_EVICT_WALK_INCR 100 /* Pages added each walk */
/*
* WT_EVICT_ENTRY --
* Encapsulation of an eviction candidate.
*/
struct __wt_evict_entry {
WT_BTREE *btree; /* Enclosing btree object */
WT_REF *ref; /* Page to flush/evict */
uint64_t score; /* Relative eviction priority */
};
#define WT_EVICT_QUEUE_MAX 3 /* Two ordinary queues plus urgent */
#define WT_EVICT_URGENT_QUEUE 2 /* Urgent queue index */
/*
* WT_EVICT_QUEUE --
* Encapsulation of an eviction candidate queue.
*/
struct __wt_evict_queue {
WT_SPINLOCK evict_lock; /* Eviction LRU queue */
WT_EVICT_ENTRY *evict_queue; /* LRU pages being tracked */
WT_EVICT_ENTRY *evict_current; /* LRU current page to be evicted */
uint32_t evict_candidates; /* LRU list pages to evict */
uint32_t evict_entries; /* LRU entries in the queue */
volatile uint32_t evict_max; /* LRU maximum eviction slot used */
};
/* Cache operations. */
typedef enum __wt_cache_op {
WT_SYNC_CHECKPOINT,
WT_SYNC_CLOSE,
WT_SYNC_DISCARD,
WT_SYNC_WRITE_LEAVES
} WT_CACHE_OP;
/*
* WiredTiger cache structure.
*/
struct __wt_cache {
/*
* Different threads read/write pages to/from the cache and create pages
* in the cache, so we cannot know precisely how much memory is in use
* at any specific time. However, even though the values don't have to
* be exact, they can't be garbage, we track what comes in and what goes
* out and calculate the difference as needed.
*/
uint64_t bytes_dirty_intl; /* Bytes/pages currently dirty */
uint64_t pages_dirty_intl;
uint64_t bytes_dirty_leaf;
uint64_t pages_dirty_leaf;
uint64_t bytes_evict; /* Bytes/pages discarded by eviction */
uint64_t pages_evict;
uint64_t pages_evicted; /* Pages evicted during a pass */
uint64_t bytes_image; /* Bytes of disk images */
uint64_t bytes_inmem; /* Bytes/pages in memory */
uint64_t pages_inmem;
uint64_t bytes_internal; /* Bytes of internal pages */
uint64_t bytes_read; /* Bytes read into memory */
uint64_t bytes_written;
uint64_t app_waits; /* User threads waited for cache */
uint64_t app_evicts; /* Pages evicted by user threads */
uint64_t server_evicts; /* Pages evicted by server thread */
uint64_t worker_evicts; /* Pages evicted by worker threads */
uint64_t evict_max_page_size; /* Largest page seen at eviction */
#ifdef HAVE_DIAGNOSTIC
struct timespec stuck_ts; /* Stuck timestamp */
#endif
/*
* Read information.
*/
uint64_t read_gen; /* Current page read generation */
uint64_t read_gen_oldest; /* Oldest read generation the eviction
* server saw in its last queue load */
/*
* Eviction thread information.
*/
WT_CONDVAR *evict_cond; /* Eviction server condition */
WT_SPINLOCK evict_walk_lock; /* Eviction walk location */
u_int eviction_dirty_target; /* Percent to allow dirty */
u_int eviction_dirty_trigger; /* Percent to trigger dirty eviction */
u_int eviction_trigger; /* Percent to trigger eviction */
u_int eviction_target; /* Percent to end eviction */
u_int eviction_checkpoint_target;/* Percent to reduce dirty
to during checkpoint scrubs */
double eviction_scrub_limit; /* Percent of cache to trigger
dirty eviction during checkpoint
scrubs */
u_int overhead_pct; /* Cache percent adjustment */
/*
* Pass interrupt counter.
*/
volatile uint32_t pass_intr; /* Interrupt eviction pass. */
/*
* LRU eviction list information.
*/
WT_SPINLOCK evict_pass_lock; /* Eviction pass lock */
WT_SESSION_IMPL *walk_session; /* Eviction pass session */
WT_DATA_HANDLE *evict_file_next;/* LRU next file to search */
WT_SPINLOCK evict_queue_lock; /* Eviction current queue lock */
WT_EVICT_QUEUE evict_queues[WT_EVICT_QUEUE_MAX];
WT_EVICT_QUEUE *evict_current_queue; /* LRU current queue in use */
WT_EVICT_QUEUE *evict_fill_queue; /* LRU next queue to fill.
This is usually the same as the
"other" queue but under heavy
load the eviction server will
start filling the current queue
before it switches. */
WT_EVICT_QUEUE *evict_other_queue; /* LRU queue not in use */
WT_EVICT_QUEUE *evict_urgent_queue; /* LRU urgent queue */
uint32_t evict_slots; /* LRU list eviction slots */
#define WT_EVICT_SCORE_BUMP 10
#define WT_EVICT_SCORE_CUTOFF 10
#define WT_EVICT_SCORE_MAX 100
uint32_t evict_aggressive_score;/* Score of how aggressive eviction
should be about selecting eviction
candidates. If eviction is
struggling to make progress, this
score rises (up to a maximum of
100), at which point the cache is
"stuck" and transaction will be
rolled back. */
uint32_t evict_empty_score; /* Score of how often LRU queues are
empty on refill. This score varies
between 0 (if the queue hasn't been
empty for a long time) and 100 (if
the queue has been empty the last 10
times we filled up. */
/*
* Cache pool information.
*/
uint64_t cp_pass_pressure; /* Calculated pressure from this pass */
uint64_t cp_quota; /* Maximum size for this cache */
uint64_t cp_reserved; /* Base size for this cache */
WT_SESSION_IMPL *cp_session; /* May be used for cache management */
uint32_t cp_skip_count; /* Post change stabilization */
wt_thread_t cp_tid; /* Thread ID for cache pool manager */
/* State seen at the last pass of the shared cache manager */
uint64_t cp_saved_app_evicts; /* User eviction count at last review */
uint64_t cp_saved_app_waits; /* User wait count at last review */
uint64_t cp_saved_read; /* Read count at last review */
/*
* Flags.
*/
#define WT_CACHE_EVICT_CLEAN 0x001 /* Evict clean pages */
#define WT_CACHE_EVICT_CLEAN_HARD 0x002 /* Clean % blocking app threads */
#define WT_CACHE_EVICT_DIRTY 0x004 /* Evict dirty pages */
#define WT_CACHE_EVICT_DIRTY_HARD 0x008 /* Dirty % blocking app threads */
#define WT_CACHE_EVICT_SCRUB 0x010 /* Scrub dirty pages pages */
#define WT_CACHE_EVICT_URGENT 0x020 /* Pages are in the urgent queue */
#define WT_CACHE_EVICT_ALL (WT_CACHE_EVICT_CLEAN | WT_CACHE_EVICT_DIRTY)
#define WT_CACHE_EVICT_MASK 0x0FF
#define WT_CACHE_POOL_MANAGER 0x100 /* The active cache pool manager */
#define WT_CACHE_POOL_RUN 0x200 /* Cache pool thread running */
uint32_t flags;
};
#define WT_WITH_PASS_LOCK(session, ret, op) do { \
WT_ASSERT(session, !F_ISSET(session, WT_SESSION_LOCKED_PASS)); \
WT_WITH_LOCK(session, ret, \
&cache->evict_pass_lock, WT_SESSION_LOCKED_PASS, op); \
} while (0)
/*
* WT_CACHE_POOL --
* A structure that represents a shared cache.
*/
struct __wt_cache_pool {
WT_SPINLOCK cache_pool_lock;
WT_CONDVAR *cache_pool_cond;
const char *name;
uint64_t size;
uint64_t chunk;
uint64_t quota;
uint64_t currently_used;
uint32_t refs; /* Reference count for structure. */
/* Locked: List of connections participating in the cache pool. */
TAILQ_HEAD(__wt_cache_pool_qh, __wt_connection_impl) cache_pool_qh;
uint8_t pool_managed; /* Cache pool has a manager thread */
#define WT_CACHE_POOL_ACTIVE 0x01 /* Cache pool is active */
uint8_t flags;
};
|
