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
|
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "memory/jemalloc_nodump_allocator.h"
#include <string>
#include <thread>
#include "port/likely.h"
#include "port/port.h"
#include "util/string_util.h"
namespace ROCKSDB_NAMESPACE {
#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
std::atomic<extent_alloc_t*> JemallocNodumpAllocator::original_alloc_{nullptr};
JemallocNodumpAllocator::JemallocNodumpAllocator(
JemallocAllocatorOptions& options,
std::unique_ptr<extent_hooks_t>&& arena_hooks, unsigned arena_index)
: options_(options),
arena_hooks_(std::move(arena_hooks)),
arena_index_(arena_index),
tcache_(&JemallocNodumpAllocator::DestroyThreadSpecificCache) {}
int JemallocNodumpAllocator::GetThreadSpecificCache(size_t size) {
// We always enable tcache. The only corner case is when there are a ton of
// threads accessing with low frequency, then it could consume a lot of
// memory (may reach # threads * ~1MB) without bringing too much benefit.
if (options_.limit_tcache_size && (size <= options_.tcache_size_lower_bound ||
size > options_.tcache_size_upper_bound)) {
return MALLOCX_TCACHE_NONE;
}
unsigned* tcache_index = reinterpret_cast<unsigned*>(tcache_.Get());
if (UNLIKELY(tcache_index == nullptr)) {
// Instantiate tcache.
tcache_index = new unsigned(0);
size_t tcache_index_size = sizeof(unsigned);
int ret =
mallctl("tcache.create", tcache_index, &tcache_index_size, nullptr, 0);
if (ret != 0) {
// No good way to expose the error. Silently disable tcache.
delete tcache_index;
return MALLOCX_TCACHE_NONE;
}
tcache_.Reset(static_cast<void*>(tcache_index));
}
return MALLOCX_TCACHE(*tcache_index);
}
void* JemallocNodumpAllocator::Allocate(size_t size) {
int tcache_flag = GetThreadSpecificCache(size);
return mallocx(size, MALLOCX_ARENA(arena_index_) | tcache_flag);
}
void JemallocNodumpAllocator::Deallocate(void* p) {
// Obtain tcache.
size_t size = 0;
if (options_.limit_tcache_size) {
size = malloc_usable_size(p);
}
int tcache_flag = GetThreadSpecificCache(size);
// No need to pass arena index to dallocx(). Jemalloc will find arena index
// from its own metadata.
dallocx(p, tcache_flag);
}
void* JemallocNodumpAllocator::Alloc(extent_hooks_t* extent, void* new_addr,
size_t size, size_t alignment, bool* zero,
bool* commit, unsigned arena_ind) {
extent_alloc_t* original_alloc =
original_alloc_.load(std::memory_order_relaxed);
assert(original_alloc != nullptr);
void* result = original_alloc(extent, new_addr, size, alignment, zero, commit,
arena_ind);
if (result != nullptr) {
int ret = madvise(result, size, MADV_DONTDUMP);
if (ret != 0) {
fprintf(
stderr,
"JemallocNodumpAllocator failed to set MADV_DONTDUMP, error code: %d",
ret);
assert(false);
}
}
return result;
}
Status JemallocNodumpAllocator::DestroyArena(unsigned arena_index) {
assert(arena_index != 0);
std::string key = "arena." + ToString(arena_index) + ".destroy";
int ret = mallctl(key.c_str(), nullptr, 0, nullptr, 0);
if (ret != 0) {
return Status::Incomplete("Failed to destroy jemalloc arena, error code: " +
ToString(ret));
}
return Status::OK();
}
void JemallocNodumpAllocator::DestroyThreadSpecificCache(void* ptr) {
assert(ptr != nullptr);
unsigned* tcache_index = static_cast<unsigned*>(ptr);
size_t tcache_index_size = sizeof(unsigned);
int ret __attribute__((__unused__)) =
mallctl("tcache.destroy", nullptr, 0, tcache_index, tcache_index_size);
// Silently ignore error.
assert(ret == 0);
delete tcache_index;
}
JemallocNodumpAllocator::~JemallocNodumpAllocator() {
// Destroy tcache before destroying arena.
autovector<void*> tcache_list;
tcache_.Scrape(&tcache_list, nullptr);
for (void* tcache_index : tcache_list) {
DestroyThreadSpecificCache(tcache_index);
}
// Destroy arena. Silently ignore error.
Status s __attribute__((__unused__)) = DestroyArena(arena_index_);
assert(s.ok());
}
size_t JemallocNodumpAllocator::UsableSize(void* p,
size_t /*allocation_size*/) const {
return malloc_usable_size(static_cast<void*>(p));
}
#endif // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
Status NewJemallocNodumpAllocator(
JemallocAllocatorOptions& options,
std::shared_ptr<MemoryAllocator>* memory_allocator) {
*memory_allocator = nullptr;
Status unsupported = Status::NotSupported(
"JemallocNodumpAllocator only available with jemalloc version >= 5 "
"and MADV_DONTDUMP is available.");
#ifndef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
(void)options;
return unsupported;
#else
if (!HasJemalloc()) {
return unsupported;
}
if (memory_allocator == nullptr) {
return Status::InvalidArgument("memory_allocator must be non-null.");
}
if (options.limit_tcache_size &&
options.tcache_size_lower_bound >= options.tcache_size_upper_bound) {
return Status::InvalidArgument(
"tcache_size_lower_bound larger or equal to tcache_size_upper_bound.");
}
// Create arena.
unsigned arena_index = 0;
size_t arena_index_size = sizeof(arena_index);
int ret =
mallctl("arenas.create", &arena_index, &arena_index_size, nullptr, 0);
if (ret != 0) {
return Status::Incomplete("Failed to create jemalloc arena, error code: " +
ToString(ret));
}
assert(arena_index != 0);
// Read existing hooks.
std::string key = "arena." + ToString(arena_index) + ".extent_hooks";
extent_hooks_t* hooks;
size_t hooks_size = sizeof(hooks);
ret = mallctl(key.c_str(), &hooks, &hooks_size, nullptr, 0);
if (ret != 0) {
JemallocNodumpAllocator::DestroyArena(arena_index);
return Status::Incomplete("Failed to read existing hooks, error code: " +
ToString(ret));
}
// Store existing alloc.
extent_alloc_t* original_alloc = hooks->alloc;
extent_alloc_t* expected = nullptr;
bool success =
JemallocNodumpAllocator::original_alloc_.compare_exchange_strong(
expected, original_alloc);
if (!success && original_alloc != expected) {
JemallocNodumpAllocator::DestroyArena(arena_index);
return Status::Incomplete("Original alloc conflict.");
}
// Set the custom hook.
std::unique_ptr<extent_hooks_t> new_hooks(new extent_hooks_t(*hooks));
new_hooks->alloc = &JemallocNodumpAllocator::Alloc;
extent_hooks_t* hooks_ptr = new_hooks.get();
ret = mallctl(key.c_str(), nullptr, nullptr, &hooks_ptr, sizeof(hooks_ptr));
if (ret != 0) {
JemallocNodumpAllocator::DestroyArena(arena_index);
return Status::Incomplete("Failed to set custom hook, error code: " +
ToString(ret));
}
// Create cache allocator.
memory_allocator->reset(
new JemallocNodumpAllocator(options, std::move(new_hooks), arena_index));
return Status::OK();
#endif // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
}
} // namespace ROCKSDB_NAMESPACE
|
