1 /**
2 * collectd - src/cgroups.c
3 * Copyright (C) 2011 Michael Stapelberg
4 * Copyright (C) 2013 Florian Forster
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; only version 2 of the license is applicable.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors:
20 * Michael Stapelberg <michael at stapelberg.de>
21 * Florian Forster <octo at collectd.org>
22 **/
24 #include "collectd.h"
26 #include "common.h"
27 #include "plugin.h"
28 #include "utils_mount.h"
29 #include "utils_ignorelist.h"
31 static char const *config_keys[] =
32 {
33 "CGroup",
34 "IgnoreSelected"
35 };
36 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
38 static ignorelist_t *il_cgroup = NULL;
40 __attribute__ ((nonnull(1)))
41 __attribute__ ((nonnull(2)))
42 static void cgroups_submit_one (char const *plugin_instance,
43 char const *type_instance, value_t value)
44 {
45 value_list_t vl = VALUE_LIST_INIT;
47 vl.values = &value;
48 vl.values_len = 1;
49 sstrncpy (vl.plugin, "cgroups", sizeof (vl.plugin));
50 sstrncpy (vl.plugin_instance, plugin_instance,
51 sizeof (vl.plugin_instance));
52 sstrncpy (vl.type, "cpu", sizeof (vl.type));
53 sstrncpy (vl.type_instance, type_instance,
54 sizeof (vl.type_instance));
56 plugin_dispatch_values (&vl);
57 } /* void cgroups_submit_one */
59 /*
60 * This callback reads the user/system CPU time for each cgroup.
61 */
62 static int read_cpuacct_procs (const char *dirname, char const *cgroup_name,
63 void *user_data)
64 {
65 char abs_path[PATH_MAX];
66 struct stat statbuf;
67 char buf[1024];
68 int status;
70 FILE *fh;
72 if (ignorelist_match (il_cgroup, cgroup_name))
73 return (0);
75 ssnprintf (abs_path, sizeof (abs_path), "%s/%s", dirname, cgroup_name);
77 status = lstat (abs_path, &statbuf);
78 if (status != 0)
79 {
80 ERROR ("cgroups plugin: stat (\"%s\") failed.",
81 abs_path);
82 return (-1);
83 }
85 /* We are only interested in directories, so skip everything else. */
86 if (!S_ISDIR (statbuf.st_mode))
87 return (0);
89 ssnprintf (abs_path, sizeof (abs_path), "%s/%s/cpuacct.stat",
90 dirname, cgroup_name);
91 fh = fopen (abs_path, "r");
92 if (fh == NULL)
93 {
94 char errbuf[1024];
95 ERROR ("cgroups plugin: fopen (\"%s\") failed: %s",
96 abs_path,
97 sstrerror (errno, errbuf, sizeof (errbuf)));
98 return (-1);
99 }
101 while (fgets (buf, sizeof (buf), fh) != NULL)
102 {
103 char *fields[8];
104 int numfields = 0;
105 char *key;
106 size_t key_len;
107 value_t value;
109 /* Expected format:
110 *
111 * user: 12345
112 * system: 23456
113 *
114 * Or:
115 *
116 * user 12345
117 * system 23456
118 */
119 strstripnewline (buf);
120 numfields = strsplit (buf, fields, STATIC_ARRAY_SIZE (fields));
121 if (numfields != 2)
122 continue;
124 key = fields[0];
125 key_len = strlen (key);
126 if (key_len < 2)
127 continue;
129 /* Strip colon off the first column, if found */
130 if (key[key_len - 1] == ':')
131 key[key_len - 1] = 0;
133 status = parse_value (fields[1], &value, DS_TYPE_DERIVE);
134 if (status != 0)
135 continue;
137 cgroups_submit_one (cgroup_name, key, value);
138 }
140 fclose (fh);
141 return (0);
142 } /* int read_cpuacct_procs */
144 /*
145 * Gets called for every file/folder in /sys/fs/cgroup/cpu,cpuacct (or
146 * wherever cpuacct is mounted on the system). Calls walk_directory with the
147 * read_cpuacct_procs callback on every folder it finds, such as "system".
148 */
149 static int read_cpuacct_root (const char *dirname, const char *filename,
150 void *user_data)
151 {
152 char abs_path[PATH_MAX];
153 struct stat statbuf;
154 int status;
156 ssnprintf (abs_path, sizeof (abs_path), "%s/%s", dirname, filename);
158 status = lstat (abs_path, &statbuf);
159 if (status != 0)
160 {
161 ERROR ("cgroups plugin: stat (%s) failed.", abs_path);
162 return (-1);
163 }
165 if (S_ISDIR (statbuf.st_mode))
166 {
167 status = walk_directory (abs_path, read_cpuacct_procs,
168 /* user_data = */ NULL,
169 /* include_hidden = */ 0);
170 return (status);
171 }
173 return (0);
174 }
176 static int cgroups_init (void)
177 {
178 if (il_cgroup == NULL)
179 il_cgroup = ignorelist_create (1);
181 return (0);
182 }
184 static int cgroups_config (const char *key, const char *value)
185 {
186 cgroups_init ();
188 if (strcasecmp (key, "CGroup") == 0)
189 {
190 if (ignorelist_add (il_cgroup, value))
191 return (1);
192 return (0);
193 }
194 else if (strcasecmp (key, "IgnoreSelected") == 0)
195 {
196 if (IS_TRUE (value))
197 ignorelist_set_invert (il_cgroup, 0);
198 else
199 ignorelist_set_invert (il_cgroup, 1);
200 return (0);
201 }
203 return (-1);
204 }
206 static int cgroups_read (void)
207 {
208 cu_mount_t *mnt_list = NULL;
209 _Bool cgroup_found = 0;
211 if (cu_mount_getlist (&mnt_list) == NULL)
212 {
213 ERROR ("cgroups plugin: cu_mount_getlist failed.");
214 return (-1);
215 }
217 for (cu_mount_t *mnt_ptr = mnt_list; mnt_ptr != NULL; mnt_ptr = mnt_ptr->next)
218 {
219 /* Find the cgroup mountpoint which contains the cpuacct
220 * controller. */
221 if ((strcmp(mnt_ptr->type, "cgroup") != 0)
222 || !cu_mount_checkoption(mnt_ptr->options,
223 "cpuacct", /* full = */ 1))
224 continue;
226 walk_directory (mnt_ptr->dir, read_cpuacct_root,
227 /* user_data = */ NULL,
228 /* include_hidden = */ 0);
229 cgroup_found = 1;
230 /* It doesn't make sense to check other cpuacct mount-points
231 * (if any), they contain the same data. */
232 break;
233 }
235 cu_mount_freelist (mnt_list);
237 if (!cgroup_found)
238 {
239 WARNING ("cgroups plugin: Unable to find cgroup "
240 "mount-point with the \"cpuacct\" option.");
241 return (-1);
242 }
244 return (0);
245 } /* int cgroup_read */
247 void module_register (void)
248 {
249 plugin_register_config ("cgroups", cgroups_config,
250 config_keys, config_keys_num);
251 plugin_register_init ("cgroups", cgroups_init);
252 plugin_register_read ("cgroups", cgroups_read);
253 } /* void module_register */