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
|
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#include "Allocator.h"
#include "StupidAllocator.h"
#include "BitmapAllocator.h"
#include "AvlAllocator.h"
#include "HybridAllocator.h"
#include "common/debug.h"
#include "common/admin_socket.h"
#define dout_subsys ceph_subsys_bluestore
class Allocator::SocketHook : public AdminSocketHook {
Allocator *alloc;
friend class Allocator;
std::string name;
public:
explicit SocketHook(Allocator *alloc,
const std::string& _name) :
alloc(alloc), name(_name)
{
AdminSocket *admin_socket = g_ceph_context->get_admin_socket();
if (name.empty()) {
name = to_string((uintptr_t)this);
}
if (admin_socket) {
int r = admin_socket->register_command(("bluestore allocator dump " + name).c_str(),
("bluestore allocator dump " + name).c_str(),
this,
"dump allocator free regions");
if (r != 0)
alloc = nullptr; //some collision, disable
if (alloc) {
r = admin_socket->register_command(("bluestore allocator score " + name).c_str(),
("bluestore allocator score " + name).c_str(),
this,
"give score on allocator fragmentation (0-no fragmentation, 1-absolute fragmentation)");
ceph_assert(r == 0);
r = admin_socket->register_command(("bluestore allocator fragmentation " + name).c_str(),
("bluestore allocator fragmentation " + name).c_str(),
this,
"give allocator fragmentation (0-no fragmentation, 1-absolute fragmentation)");
ceph_assert(r == 0);
}
}
}
~SocketHook()
{
AdminSocket *admin_socket = g_ceph_context->get_admin_socket();
if (admin_socket && alloc) {
int r = admin_socket->unregister_command(("bluestore allocator dump " + name).c_str());
ceph_assert(r == 0);
r = admin_socket->unregister_command(("bluestore allocator score " + name).c_str());
ceph_assert(r == 0);
r = admin_socket->unregister_command(("bluestore allocator fragmentation " + name).c_str());
ceph_assert(r == 0);
}
}
bool call(std::string_view command, const cmdmap_t& cmdmap,
std::string_view format, bufferlist& out) override {
stringstream ss;
bool r = true;
if (command == "bluestore allocator dump " + name) {
Formatter *f = Formatter::create(format, "json-pretty", "json-pretty");
f->open_array_section("free_regions");
auto iterated_allocation = [&](size_t off, size_t len) {
ceph_assert(len > 0);
f->open_object_section("free");
char off_hex[30];
char len_hex[30];
snprintf(off_hex, sizeof(off_hex) - 1, "0x%lx", off);
snprintf(len_hex, sizeof(len_hex) - 1, "0x%lx", len);
f->dump_string("offset", off_hex);
f->dump_string("length", len_hex);
f->close_section();
};
alloc->dump(iterated_allocation);
f->close_section();
f->flush(ss);
} else if (command == "bluestore allocator score " + name) {
Formatter *f = Formatter::create(format, "json-pretty", "json-pretty");
f->open_object_section("fragmentation_score");
f->dump_float("fragmentation_rating", alloc->get_fragmentation_score());
f->close_section();
f->flush(ss);
delete f;
} else if (command == "bluestore allocator fragmentation " + name) {
Formatter* f = Formatter::create(format, "json-pretty", "json-pretty");
f->open_object_section("fragmentation");
f->dump_float("fragmentation_rating", alloc->get_fragmentation());
f->close_section();
f->flush(ss);
delete f;
} else {
ss << "Invalid command" << std::endl;
r = false;
}
out.append(ss);
return r;
}
};
Allocator::Allocator(const std::string& name)
{
asok_hook = new SocketHook(this, name);
}
Allocator::~Allocator()
{
delete asok_hook;
}
const string& Allocator::get_name() const {
return asok_hook->name;
}
Allocator *Allocator::create(CephContext* cct, string type,
int64_t size, int64_t block_size, const std::string& name)
{
Allocator* alloc = nullptr;
if (type == "stupid") {
alloc = new StupidAllocator(cct, name, block_size);
} else if (type == "bitmap") {
alloc = new BitmapAllocator(cct, size, block_size, name);
} else if (type == "avl") {
return new AvlAllocator(cct, size, block_size, name);
} else if (type == "hybrid") {
return new HybridAllocator(cct, size, block_size,
cct->_conf.get_val<uint64_t>("bluestore_hybrid_alloc_mem_cap"),
name);
}
if (alloc == nullptr) {
lderr(cct) << "Allocator::" << __func__ << " unknown alloc type "
<< type << dendl;
}
return alloc;
}
void Allocator::release(const PExtentVector& release_vec)
{
interval_set<uint64_t> release_set;
for (auto e : release_vec) {
release_set.insert(e.offset, e.length);
}
release(release_set);
}
/**
* Gives fragmentation a numeric value.
*
* Following algorithm applies value to each existing free unallocated block.
* Value of single block is a multiply of size and per-byte-value.
* Per-byte-value is greater for larger blocks.
* Assume block size X has value per-byte p; then block size 2*X will have per-byte value 1.1*p.
*
* This could be expressed in logarithms, but for speed this is interpolated inside ranges.
* [1] [2..3] [4..7] [8..15] ...
* ^ ^ ^ ^
* 1.1 1.1^2 1.1^3 1.1^4 ...
*
* Final score is obtained by proportion between score that would have been obtained
* in condition of absolute fragmentation and score in no fragmentation at all.
*/
double Allocator::get_fragmentation_score()
{
// this value represents how much worth is 2X bytes in one chunk then in X + X bytes
static const double double_size_worth = 1.1 ;
std::vector<double> scales{1};
double score_sum = 0;
size_t sum = 0;
auto get_score = [&](size_t v) -> double {
size_t sc = sizeof(v) * 8 - clz(v) - 1; //assign to grade depending on log2(len)
while (scales.size() <= sc + 1) {
//unlikely expand scales vector
scales.push_back(scales[scales.size() - 1] * double_size_worth);
}
size_t sc_shifted = size_t(1) << sc;
double x = double(v - sc_shifted) / sc_shifted; //x is <0,1) in its scale grade
// linear extrapolation in its scale grade
double score = (sc_shifted ) * scales[sc] * (1-x) +
(sc_shifted * 2) * scales[sc+1] * x;
return score;
};
auto iterated_allocation = [&](size_t off, size_t len) {
ceph_assert(len > 0);
score_sum += get_score(len);
sum += len;
};
dump(iterated_allocation);
double ideal = get_score(sum);
double terrible = sum * get_score(1);
return (ideal - score_sum) / (ideal - terrible);
}
|
