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
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
* BIRD Internet Routing Daemon -- Raw allocation
*
* (c) 2020 Maria Matejka <mq@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "nest/bird.h"
#include "lib/resource.h"
#include "lib/lists.h"
#include "lib/event.h"
#include "sysdep/unix/io-loop.h"
#include <stdlib.h>
#include <unistd.h>
#include <stdatomic.h>
#include <errno.h>
#ifdef HAVE_MMAP
#include <sys/mman.h>
#endif
long page_size = 0;
#ifdef HAVE_MMAP
#if DEBUGGING
#define FP_NODE_OFFSET 42
#else
#define FP_NODE_OFFSET 1
#endif
static _Bool use_fake = 0;
#else
static _Bool use_fake = 1;
#endif
static void *
alloc_sys_page(void)
{
void *ptr = mmap(NULL, page_size, PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (ptr == MAP_FAILED)
bug("mmap(%lu) failed: %m", page_size);
return ptr;
}
extern int shutting_down; /* Shutdown requested. */
void *
alloc_page(void)
{
#ifdef HAVE_MMAP
if (!use_fake)
{
struct free_pages *fp = &birdloop_current->pages;
if (!fp->cnt)
return alloc_sys_page();
node *n = HEAD(fp->list);
rem_node(n);
if (!shutting_down && (--fp->cnt < fp->min))
ev_send(&global_work_list, fp->cleanup);
void *ptr = n - FP_NODE_OFFSET;
memset(ptr, 0, page_size);
return ptr;
}
else
#endif
{
void *ret = aligned_alloc(page_size, page_size);
if (!ret)
bug("aligned_alloc(%lu) failed", page_size);
return ret;
}
}
void
free_page(void *ptr)
{
#ifdef HAVE_MMAP
if (!use_fake)
{
struct free_pages *fp = &birdloop_current->pages;
struct node *n = ptr;
n += FP_NODE_OFFSET;
memset(n, 0, sizeof(node));
add_tail(&fp->list, n);
if (!shutting_down && (++fp->cnt > fp->max))
ev_send(&global_work_list, fp->cleanup);
}
else
#endif
free(ptr);
}
#ifdef HAVE_MMAP
#define GFP (&main_birdloop.pages)
void
flush_pages(struct birdloop *loop)
{
ASSERT_DIE(birdloop_inside(&main_birdloop));
add_tail_list(&GFP->list, &loop->pages.list);
GFP->cnt += loop->pages.cnt;
loop->pages.cnt = 0;
loop->pages.list = (list) {};
loop->pages.min = 0;
loop->pages.max = 0;
rfree(loop->pages.cleanup);
loop->pages.cleanup = NULL;
}
static void
cleanup_pages(void *data)
{
struct birdloop *loop = data;
birdloop_enter(loop);
struct free_pages *fp = &birdloop_current->pages;
while ((fp->cnt < fp->min) && (GFP->cnt > GFP->min))
{
node *n = HEAD(GFP->list);
rem_node(n);
add_tail(&fp->list, n);
fp->cnt++;
GFP->cnt--;
}
while (fp->cnt < fp->min)
{
node *n = alloc_sys_page();
add_tail(&fp->list, n + FP_NODE_OFFSET);
fp->cnt++;
}
while (fp->cnt > fp->max)
{
node *n = HEAD(fp->list);
rem_node(n);
add_tail(&GFP->list, n);
fp->cnt--;
GFP->cnt++;
}
birdloop_leave(loop);
if (!shutting_down && (GFP->cnt > GFP->max))
ev_send(&global_work_list, GFP->cleanup);
}
static void
cleanup_global_pages(void *data UNUSED)
{
while (GFP->cnt < GFP->max)
{
node *n = alloc_sys_page();
add_tail(&GFP->list, n + FP_NODE_OFFSET);
GFP->cnt++;
}
for (uint limit = GFP->cnt; (limit > 0) && (GFP->cnt > GFP->max); limit--)
{
node *n = TAIL(GFP->list);
rem_node(n);
if (munmap(n - FP_NODE_OFFSET, page_size) == 0)
GFP->cnt--;
else if (errno == ENOMEM)
add_head(&GFP->list, n);
else
bug("munmap(%p) failed: %m", n - FP_NODE_OFFSET);
}
}
void
init_pages(struct birdloop *loop)
{
struct free_pages *fp = &loop->pages;
init_list(&fp->list);
fp->cleanup = ev_new_init(&root_pool, cleanup_pages, loop);
fp->min = 4;
fp->max = 16;
for (fp->cnt = 0; fp->cnt < fp->min; fp->cnt++)
{
node *n = alloc_sys_page();
add_tail(&fp->list, n + FP_NODE_OFFSET);
}
}
static event global_free_pages_cleanup_event = { .hook = cleanup_global_pages };
void resource_sys_init(void)
{
if (!(page_size = sysconf(_SC_PAGESIZE)))
die("System page size must be non-zero");
if (u64_popcount(page_size) == 1)
{
init_list(&GFP->list);
GFP->cleanup = &global_free_pages_cleanup_event;
GFP->min = 0;
GFP->max = 256;
return;
}
log(L_WARN "Got strange memory page size (%lu), using the aligned allocator instead", page_size);
/* Too big or strange page, use the aligned allocator instead */
page_size = 4096;
use_fake = 1;
}
#else
void
resource_sys_init(void)
{
page_size = 4096;
use_fake = 1;
}
#endif
|
