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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
|
/* Expanded ashmem test -- flex input, but mostly -*-C-*- really */
%option noyywrap yylineno
%{
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/sysinfo.h>
#ifdef ANDROID
#include <utils/ashmem.h>
#else
#include "ashmem.h"
#endif
#ifndef _LINUX_ASHMEM_H
struct ashmem_pin {
uint32_t offset;
uint32_t len;
};
#endif
typedef struct {
int beg;
int end;
} range_t;
int ashmemfd = -1;
void *pages;
int nrpages;
int pagesize;
int parse_number (char *);
range_t * parse_range (char *);
void getpages (int);
void pinpages (range_t *);
void unpinpages (range_t *);
void shrink (void);
void purgepages (void);
void fatal (int, const char *, ...);
%}
%%
getpages[ \t]+[0-9]+ { getpages (parse_number (yytext + 8)); }
pin[ \t]+[0-9]+[ \t]+[0-9]+ { pinpages (parse_range (yytext + 3)); }
unpin[ \t]+[0-9]+[ \t]+[0-9]+ { unpinpages (parse_range (yytext + 5)); }
shrink { shrink (); }
purge { purgepages (); }
[ \t\n]+ /* spaces */
[ \t]*#.* /* comment starts from '#' */
. { fprintf (stderr, "Unrecognized input '%s' at line %d\n",
yytext, yylineno);
exit (1); }
%%
void fatal (int error, const char *fmt, ...)
{
va_list ap;
va_start (ap, fmt);
vfprintf (stderr, fmt, ap);
if (error)
fprintf (stderr, " (error %d [%s])", error, strerror (error));
va_end (ap);
fprintf (stderr, "\n");
exit (error ? error : 1);
}
int
parse_number (char *buf)
{
while (isspace (*buf))
buf++;
return atoi (buf);
}
range_t *
parse_range (char *buf)
{
char *p, *q;
range_t *range;
if (ashmemfd == -1)
fatal (0, "pages not allocated (use getpages X first)");
range = (range_t *) malloc (sizeof (range_t));
if (!range)
fatal (0, "cannot allocate memory");
for (p = buf; isspace (*p); p++);
if (!isdigit (*p))
fatal (0, "unexpected parse error");
range->beg = strtol (p, &q, 10);
for (; isspace (*q); q++);
range->end = strtol (q, NULL, 10);
if (range->beg > nrpages)
fatal (0, "range begin %d is outside of allocated pages", range->beg);
if (range->end > nrpages)
fatal (0, "range end %d is outside of allocated pages", range->beg);
if (range->end == range->beg)
fatal (0, "zero-sized range at line %d", yylineno);
return range;
}
void
getpages (int npages)
{
size_t size = npages * pagesize;
if (ashmemfd != -1)
fatal (0, "pages already allocated");
if (npages < 1)
fatal (0, "should allocate at least one page");
ashmemfd = open ("/dev/ashmem", O_RDWR);
if (ashmemfd < 0)
fatal (errno, "can't open /dev/ashmem");
if (ioctl (ashmemfd, ASHMEM_SET_SIZE, size) < 0)
fatal (errno, "can't set size");
pages = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, ashmemfd, 0);
if (pages == MAP_FAILED)
fatal (errno, "can't map pages");
nrpages = npages;
printf ("-> got %d pages\n", npages);
}
void
pinpages (range_t *range)
{
struct ashmem_pin pin;
int ret;
if (ashmemfd == -1)
fatal (0, "pages not allocated (use getpages X first)");
if (range->end > range->beg)
{
/* Normal order, pin all at once. */
pin.offset = range->beg * pagesize;
pin.len = (range->end - range->beg) * pagesize;
ret = ioctl (ashmemfd, ASHMEM_PIN, &pin);
if (ret < 0)
fatal (errno, "can't pin %d..%d", range->beg, range->end);
printf ("-> pin %d..%d OK ret %d\n", range->beg, range->end, ret);
}
else
{
/* Reverse order, pin page-by-page from higher to lower. */
int pgno;
for (pgno = range->beg - 1; pgno >= range->end; pgno--)
{
pin.offset = pgno * pagesize;
pin.len = pagesize;
ret = ioctl (ashmemfd, ASHMEM_PIN, &pin);
if (ret < 0)
fatal (errno, "can't pin page %d", pgno);
}
printf ("-> pin backward %d..%d OK\n", range->beg, range->end);
}
}
void
unpinpages (range_t *range)
{
struct ashmem_pin pin;
int ret;
if (ashmemfd == -1)
fatal (0, "pages not allocated (use getpages X first)");
if (range->end > range->beg)
{
/* Normal order, unpin all at once. */
pin.offset = range->beg * pagesize;
pin.len = (range->end - range->beg) * pagesize;
ret = ioctl (ashmemfd, ASHMEM_UNPIN, &pin);
if (ret < 0)
fatal (errno, "can't unpin %d..%d", range->beg, range->end);
printf ("-> unpin %d..%d OK ret %d\n", range->beg, range->end, ret);
}
else
{
/* Reverse order, unpin page-by-page from higher to lower. */
int pgno;
for (pgno = range->beg - 1; pgno >= range->end; pgno--)
{
pin.offset = pgno * pagesize;
pin.len = pagesize;
ret = ioctl (ashmemfd, ASHMEM_UNPIN, &pin);
if (ret < 0)
fatal (errno, "can't unpin page %d", pgno);
}
printf ("-> unpin backward %d..%d OK\n", range->beg, range->end);
}
}
/* Enforce the kernel to run cache shrinker */
void
shrink (void)
{
int fd;
char cmd[2];
fd = open ("/proc/sys/vm/drop_caches", O_WRONLY);
if (fd < 0)
fatal (errno, "can't open /proc/sys/vm/drop_caches (is /proc mounted?)");
cmd[0] = '3';
cmd[1] = '\n';
if (write (fd, cmd, sizeof cmd) != sizeof cmd)
fatal (errno, "can't write to /proc/sys/vm/drop_caches");
}
void
purgepages (void)
{
int ret;
if (ashmemfd == -1)
fatal (0, "pages not allocated (use getpages X first)");
ret = ioctl (ashmemfd, ASHMEM_PURGE_ALL_CACHES);
if (ret < 0)
fatal (errno, "can't purge caches");
printf ("-> purge return %d pages OK\n", ret);
}
int main (int argc, char *argv[])
{
pagesize = getpagesize ();
if (argc == 2)
{
yyin = fopen (argv[1], "r");
if (!yyin)
fatal (errno, "can't open '%s'", argv[1]);
}
else
yyin = stdin;
yylex ();
return 0;
}
|
