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
|
// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include "mmap_file_allocator.h"
#include "round_up_to_page_size.h"
#include "exceptions.h"
#include "stringfmt.h"
#include <vespa/vespalib/stllike/hash_map.hpp>
#include <fcntl.h>
#include <sys/mman.h>
#include <cassert>
#include <filesystem>
using vespalib::make_string_short::fmt;
namespace fs = std::filesystem;
namespace vespalib::alloc {
MmapFileAllocator::MmapFileAllocator(const vespalib::string& dir_name)
: MmapFileAllocator(dir_name, default_small_limit, default_premmap_size)
{
}
MmapFileAllocator::MmapFileAllocator(const vespalib::string& dir_name, uint32_t small_limit, uint32_t premmap_size)
: _dir_name(dir_name),
_small_limit(small_limit),
_premmap_size(premmap_size),
_file(_dir_name + "/swapfile"),
_end_offset(0),
_allocations(),
_freelist(),
_small_allocations(),
_small_freelist(),
_premmapped_areas()
{
fs::create_directories(fs::path(_dir_name));
_file.open(O_RDWR | O_CREAT | O_TRUNC, false);
}
MmapFileAllocator::~MmapFileAllocator()
{
assert(_small_allocations.empty());
assert(_allocations.size() == _premmapped_areas.size());
for (auto& area : _premmapped_areas) {
auto offset = area.first;
auto ptr = area.second;
auto itr = _allocations.find(ptr);
assert(itr != _allocations.end());
assert(itr->first == ptr);
assert(itr->second.offset == offset);
auto size = itr->second.size;
_small_freelist.remove_premmapped_area(offset, size);
free_large({ptr, size});
}
_premmapped_areas.clear();
assert(_allocations.empty());
_file.close();
_file.unlink();
fs::remove_all(fs::path(_dir_name));
}
uint64_t
MmapFileAllocator::alloc_area(size_t sz) const
{
uint64_t offset = _freelist.alloc(sz);
if (offset != FileAreaFreeList::bad_offset) {
return offset;
}
offset = _end_offset;
_end_offset += sz;
_file.resize(_end_offset);
return offset;
}
PtrAndSize
MmapFileAllocator::alloc(size_t sz) const
{
if (sz == 0) {
return PtrAndSize(); // empty allocation
}
static constexpr size_t alignment = 128;
sz = (sz + alignment - 1) & -alignment; // round sz to a multiple of alignment
if (sz >= _small_limit) {
return alloc_large(sz);
} else {
return alloc_small(sz);
}
}
PtrAndSize
MmapFileAllocator::alloc_large(size_t sz) const
{
sz = round_up_to_page_size(sz);
uint64_t offset = alloc_area(sz);
void *buf = mmap(nullptr, sz, PROT_READ | PROT_WRITE, MAP_SHARED, _file.getFileDescriptor(), offset);
if (buf == MAP_FAILED) {
throw IoException(fmt("Failed mmap(nullptr, %zu, PROT_READ | PROT_WRITE, MAP_SHARED, %s(fd=%d), %" PRIu64 "). Reason given by OS = '%s'",
sz, _file.getFilename().c_str(), _file.getFileDescriptor(), offset, getLastErrorString().c_str()),
IoException::getErrorType(errno), VESPA_STRLOC);
}
assert(buf != nullptr);
// Register allocation
auto ins_res = _allocations.insert(std::make_pair(buf, SizeAndOffset(sz, offset)));
assert(ins_res.second);
int retval = madvise(buf, sz, MADV_RANDOM);
assert(retval == 0);
#ifdef __linux__
retval = madvise(buf, sz, MADV_DONTDUMP);
assert(retval == 0);
#endif
return PtrAndSize(buf, sz);
}
void*
MmapFileAllocator::map_premapped_offset_to_ptr(uint64_t offset, size_t size) const
{
auto itr = _premmapped_areas.lower_bound(offset);
if (itr == _premmapped_areas.end() || itr->first > offset) {
assert(itr != _premmapped_areas.begin());
--itr;
}
auto aitr = _allocations.find(itr->second);
assert(aitr != _allocations.end());
assert(aitr->first == itr->second);
assert(offset >= aitr->second.offset);
assert(offset + size <= aitr->second.offset + aitr->second.size);
return static_cast<char*>(itr->second) + (offset - aitr->second.offset);
}
PtrAndSize
MmapFileAllocator::alloc_small(size_t sz) const
{
uint64_t offset = _small_freelist.alloc(sz);
if (offset == FileAreaFreeList::bad_offset) {
auto new_premmap = alloc_large(_premmap_size);
assert(new_premmap.size() >= _premmap_size);
auto itr = _allocations.find(new_premmap.get());
assert(itr != _allocations.end());
assert(itr->first == new_premmap.get());
_small_freelist.add_premmapped_area(itr->second.offset, itr->second.size);
auto ins_res = _premmapped_areas.emplace(itr->second.offset, new_premmap.get());
assert(ins_res.second);
offset = _small_freelist.alloc(sz);
assert(offset != FileAreaFreeList::bad_offset);
}
auto ptr = map_premapped_offset_to_ptr(offset, sz);
// Register allocation
auto ins_res = _small_allocations.insert(std::make_pair(ptr, SizeAndOffset(sz, offset)));
assert(ins_res.second);
return {ptr, sz};
}
void
MmapFileAllocator::free(PtrAndSize alloc) const noexcept
{
if (alloc.size() == 0) {
assert(alloc.get() == nullptr);
return; // empty allocation
}
assert(alloc.get() != nullptr);
if (alloc.size() >= _small_limit) {
free_large(alloc);
} else {
free_small(alloc);
}
}
uint64_t
MmapFileAllocator::remove_allocation(PtrAndSize alloc, Allocations& allocations) const noexcept
{
// Check that matching allocation is registered
auto itr = allocations.find(alloc.get());
assert(itr != allocations.end());
assert(itr->first == alloc.get());
assert(itr->second.size == alloc.size());
auto offset = itr->second.offset;
allocations.erase(itr);
return offset;
}
void
MmapFileAllocator::free_large(PtrAndSize alloc) const noexcept
{
auto offset = remove_allocation(alloc, _allocations);
int retval = madvise(alloc.get(), alloc.size(), MADV_DONTNEED);
assert(retval == 0);
retval = munmap(alloc.get(), alloc.size());
assert(retval == 0);
_freelist.free(offset, alloc.size());
}
void
MmapFileAllocator::free_small(PtrAndSize alloc) const noexcept
{
auto offset = remove_allocation(alloc, _small_allocations);
_small_freelist.free(offset, alloc.size());
}
size_t
MmapFileAllocator::resize_inplace(PtrAndSize, size_t) const
{
return 0;
}
}
|
