FD.io VPP  v19.04.1-1-ge4a0f9f
Vector Packet Processing
sysfs.c
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1 /*
2  * Copyright (c) 2017 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include <vppinfra/clib.h>
17 #include <vppinfra/clib_error.h>
18 #include <vppinfra/format.h>
19 
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <fcntl.h>
23 #include <dirent.h>
24 
26 clib_sysfs_write (char *file_name, char *fmt, ...)
27 {
28  u8 *s;
29  int fd;
30  clib_error_t *error = 0;
31 
32  fd = open (file_name, O_WRONLY);
33  if (fd < 0)
34  return clib_error_return_unix (0, "open `%s'", file_name);
35 
36  va_list va;
37  va_start (va, fmt);
38  s = va_format (0, fmt, &va);
39  va_end (va);
40 
41  if (write (fd, s, vec_len (s)) < 0)
42  error = clib_error_return_unix (0, "write `%s'", file_name);
43 
44  vec_free (s);
45  close (fd);
46  return error;
47 }
48 
50 clib_sysfs_read (char *file_name, char *fmt, ...)
51 {
52  unformat_input_t input;
53  u8 *s = 0;
54  int fd;
55  ssize_t sz;
56  uword result;
57 
58  fd = open (file_name, O_RDONLY);
59  if (fd < 0)
60  return clib_error_return_unix (0, "open `%s'", file_name);
61 
62  vec_validate (s, 4095);
63 
64  sz = read (fd, s, vec_len (s));
65  if (sz < 0)
66  {
67  close (fd);
68  vec_free (s);
69  return clib_error_return_unix (0, "read `%s'", file_name);
70  }
71 
72  _vec_len (s) = sz;
73  unformat_init_vector (&input, s);
74 
75  va_list va;
76  va_start (va, fmt);
77  result = va_unformat (&input, fmt, &va);
78  va_end (va);
79 
80  vec_free (s);
81  close (fd);
82 
83  if (result == 0)
84  return clib_error_return (0, "unformat error");
85 
86  return 0;
87 }
88 
89 u8 *
91 {
92  char *p, buffer[64];
94  u8 *s = 0;
95  int r;
96 
97  r = readlink (link, buffer, sizeof (buffer) - 1);
98 
99  if (r < 0)
100  return 0;
101 
102  buffer[r] = 0;
103  p = strrchr (buffer, '/');
104 
105  if (!p)
106  return 0;
107 
108  unformat_init_string (&in, p + 1, strlen (p + 1));
109  if (unformat (&in, "%s", &s) != 1)
110  clib_unix_warning ("no string?");
111  unformat_free (&in);
112 
113  return s;
114 }
115 
116 clib_error_t *
117 clib_sysfs_set_nr_hugepages (int numa_node, int log2_page_size, int nr)
118 {
119  clib_error_t *error = 0;
120  struct stat sb;
121  u8 *p = 0;
122  uword page_size;
123 
124  if (log2_page_size == 0)
125  log2_page_size = min_log2 (clib_mem_get_default_hugepage_size ());
126 
127  page_size = 1ULL << (log2_page_size - 10);
128 
129  p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
130 
131  if (stat ((char *) p, &sb) == 0)
132  {
133  if (S_ISDIR (sb.st_mode) == 0)
134  {
135  error = clib_error_return (0, "'%s' is not directory", p);
136  goto done;
137  }
138  }
139  else if (numa_node == 0)
140  {
141  vec_reset_length (p);
142  p = format (p, "/sys/kernel/mm%c", 0);
143  if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
144  {
145  error = clib_error_return (0, "'%s' does not exist or it is not "
146  "directory", p);
147  goto done;
148  }
149  }
150  else
151  {
152  error = clib_error_return (0, "'%s' does not exist", p);
153  goto done;
154  }
155 
156  _vec_len (p) -= 1;
157  p = format (p, "/hugepages/hugepages-%ukB/nr_hugepages%c", page_size, 0);
158  clib_sysfs_write ((char *) p, "%d", nr);
159 
160 done:
161  vec_free (p);
162  return error;
163 }
164 
165 
166 static clib_error_t *
167 clib_sysfs_get_xxx_hugepages (char *type, int numa_node,
168  int log2_page_size, int *val)
169 {
170  clib_error_t *error = 0;
171  struct stat sb;
172  u8 *p = 0;
173 
174  uword page_size;
175 
176  if (log2_page_size == 0)
177  log2_page_size = min_log2 (clib_mem_get_default_hugepage_size ());
178 
179  page_size = 1ULL << (log2_page_size - 10);
180 
181 
182  p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
183 
184  if (stat ((char *) p, &sb) == 0)
185  {
186  if (S_ISDIR (sb.st_mode) == 0)
187  {
188  error = clib_error_return (0, "'%s' is not directory", p);
189  goto done;
190  }
191  }
192  else if (numa_node == 0)
193  {
194  vec_reset_length (p);
195  p = format (p, "/sys/kernel/mm%c", 0);
196  if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
197  {
198  error = clib_error_return (0, "'%s' does not exist or it is not "
199  "directory", p);
200  goto done;
201  }
202  }
203  else
204  {
205  error = clib_error_return (0, "'%s' does not exist", p);
206  goto done;
207  }
208 
209  _vec_len (p) -= 1;
210  p = format (p, "/hugepages/hugepages-%ukB/%s_hugepages%c", page_size,
211  type, 0);
212  error = clib_sysfs_read ((char *) p, "%d", val);
213 
214 done:
215  vec_free (p);
216  return error;
217 }
218 
219 clib_error_t *
220 clib_sysfs_get_free_hugepages (int numa_node, int log2_page_size, int *v)
221 {
222  return clib_sysfs_get_xxx_hugepages ("free", numa_node, log2_page_size, v);
223 }
224 
225 clib_error_t *
226 clib_sysfs_get_nr_hugepages (int numa_node, int log2_page_size, int *v)
227 {
228  return clib_sysfs_get_xxx_hugepages ("nr", numa_node, log2_page_size, v);
229 }
230 
231 clib_error_t *
232 clib_sysfs_get_surplus_hugepages (int numa_node, int log2_page_size, int *v)
233 {
234  return clib_sysfs_get_xxx_hugepages ("surplus", numa_node, log2_page_size,
235  v);
236 }
237 
238 clib_error_t *
239 clib_sysfs_prealloc_hugepages (int numa_node, int log2_page_size, int nr)
240 {
241  clib_error_t *error = 0;
242  int n, needed;
243  uword page_size;
244 
245  if (log2_page_size == 0)
246  log2_page_size = min_log2 (clib_mem_get_default_hugepage_size ());
247 
248  page_size = 1ULL << (log2_page_size - 10);
249 
250  error = clib_sysfs_get_free_hugepages (numa_node, log2_page_size, &n);
251  if (error)
252  return error;
253  needed = nr - n;
254  if (needed <= 0)
255  return 0;
256 
257  error = clib_sysfs_get_nr_hugepages (numa_node, log2_page_size, &n);
258  if (error)
259  return error;
260  clib_warning ("pre-allocating %u additional %uK hugepages on numa node %u",
261  needed, page_size, numa_node);
262  return clib_sysfs_set_nr_hugepages (numa_node, log2_page_size, n + needed);
263 }
264 
265 
266 /*
267  * fd.io coding-style-patch-verification: ON
268  *
269  * Local Variables:
270  * eval: (c-set-style "gnu")
271  * End:
272  */
#define vec_validate(V, I)
Make sure vector is long enough for given index (no header, unspecified alignment) ...
Definition: vec.h:439
clib_error_t * clib_sysfs_prealloc_hugepages(int numa_node, int log2_page_size, int nr)
Definition: sysfs.c:239
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:424
u8 * va_format(u8 *s, const char *fmt, va_list *va)
Definition: format.c:387
clib_error_t * clib_sysfs_write(char *file_name, char *fmt,...)
Definition: sysfs.c:26
unsigned char u8
Definition: types.h:56
static uword min_log2(uword x)
Definition: clib.h:144
#define vec_reset_length(v)
Reset vector length to zero NULL-pointer tolerant.
#define clib_error_return(e, args...)
Definition: error.h:99
void unformat_init_string(unformat_input_t *input, char *string, int string_len)
Definition: unformat.c:1023
struct _unformat_input_t unformat_input_t
#define clib_error_return_unix(e, args...)
Definition: error.h:102
clib_error_t * clib_sysfs_get_nr_hugepages(int numa_node, int log2_page_size, int *v)
Definition: sysfs.c:226
clib_error_t * clib_sysfs_read(char *file_name, char *fmt,...)
Definition: sysfs.c:50
void unformat_init_vector(unformat_input_t *input, u8 *vector_string)
Definition: unformat.c:1031
clib_error_t * clib_sysfs_get_free_hugepages(int numa_node, int log2_page_size, int *v)
Definition: sysfs.c:220
clib_error_t * clib_sysfs_get_surplus_hugepages(int numa_node, int log2_page_size, int *v)
Definition: sysfs.c:232
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:341
#define clib_warning(format, args...)
Definition: error.h:59
uword clib_mem_get_default_hugepage_size(void)
Definition: mem.c:57
#define vec_len(v)
Number of elements in vector (rvalue-only, NULL tolerant)
u64 uword
Definition: types.h:112
static void unformat_free(unformat_input_t *i)
Definition: format.h:162
#define clib_unix_warning(format, args...)
Definition: error.h:68
clib_error_t * clib_sysfs_set_nr_hugepages(int numa_node, int log2_page_size, int nr)
Definition: sysfs.c:117
uword va_unformat(unformat_input_t *i, const char *fmt, va_list *args)
Definition: unformat.c:833
uword unformat(unformat_input_t *i, const char *fmt,...)
Definition: unformat.c:972
u8 * clib_sysfs_link_to_name(char *link)
Definition: sysfs.c:90
static clib_error_t * clib_sysfs_get_xxx_hugepages(char *type, int numa_node, int log2_page_size, int *val)
Definition: sysfs.c:167