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_ignorelist.h"
29 #include "utils_mount.h"
31 static char const *config_keys[] = {"CGroup", "IgnoreSelected"};
32 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
34 static ignorelist_t *il_cgroup = NULL;
36 __attribute__((nonnull(1))) __attribute__((nonnull(2))) static void
37 cgroups_submit_one(char const *plugin_instance, char const *type_instance,
38 value_t value) {
39 value_list_t vl = VALUE_LIST_INIT;
41 vl.values = &value;
42 vl.values_len = 1;
43 sstrncpy(vl.host, hostname_g, sizeof(vl.host));
44 sstrncpy(vl.plugin, "cgroups", sizeof(vl.plugin));
45 sstrncpy(vl.plugin_instance, plugin_instance, sizeof(vl.plugin_instance));
46 sstrncpy(vl.type, "cpu", sizeof(vl.type));
47 sstrncpy(vl.type_instance, type_instance, sizeof(vl.type_instance));
49 plugin_dispatch_values(&vl);
50 } /* void cgroups_submit_one */
52 /*
53 * This callback reads the user/system CPU time for each cgroup.
54 */
55 static int read_cpuacct_procs(const char *dirname, char const *cgroup_name,
56 void *user_data) {
57 char abs_path[PATH_MAX];
58 struct stat statbuf;
59 char buf[1024];
60 int status;
62 FILE *fh;
64 if (ignorelist_match(il_cgroup, cgroup_name))
65 return (0);
67 ssnprintf(abs_path, sizeof(abs_path), "%s/%s", dirname, cgroup_name);
69 status = lstat(abs_path, &statbuf);
70 if (status != 0) {
71 ERROR("cgroups plugin: stat (\"%s\") failed.", abs_path);
72 return (-1);
73 }
75 /* We are only interested in directories, so skip everything else. */
76 if (!S_ISDIR(statbuf.st_mode))
77 return (0);
79 ssnprintf(abs_path, sizeof(abs_path), "%s/%s/cpuacct.stat", dirname,
80 cgroup_name);
81 fh = fopen(abs_path, "r");
82 if (fh == NULL) {
83 char errbuf[1024];
84 ERROR("cgroups plugin: fopen (\"%s\") failed: %s", abs_path,
85 sstrerror(errno, errbuf, sizeof(errbuf)));
86 return (-1);
87 }
89 while (fgets(buf, sizeof(buf), fh) != NULL) {
90 char *fields[8];
91 int numfields = 0;
92 char *key;
93 size_t key_len;
94 value_t value;
96 /* Expected format:
97 *
98 * user: 12345
99 * system: 23456
100 *
101 * Or:
102 *
103 * user 12345
104 * system 23456
105 */
106 strstripnewline(buf);
107 numfields = strsplit(buf, fields, STATIC_ARRAY_SIZE(fields));
108 if (numfields != 2)
109 continue;
111 key = fields[0];
112 key_len = strlen(key);
113 if (key_len < 2)
114 continue;
116 /* Strip colon off the first column, if found */
117 if (key[key_len - 1] == ':')
118 key[key_len - 1] = 0;
120 status = parse_value(fields[1], &value, DS_TYPE_DERIVE);
121 if (status != 0)
122 continue;
124 cgroups_submit_one(cgroup_name, key, value);
125 }
127 fclose(fh);
128 return (0);
129 } /* int read_cpuacct_procs */
131 /*
132 * Gets called for every file/folder in /sys/fs/cgroup/cpu,cpuacct (or
133 * wherever cpuacct is mounted on the system). Calls walk_directory with the
134 * read_cpuacct_procs callback on every folder it finds, such as "system".
135 */
136 static int read_cpuacct_root(const char *dirname, const char *filename,
137 void *user_data) {
138 char abs_path[PATH_MAX];
139 struct stat statbuf;
140 int status;
142 ssnprintf(abs_path, sizeof(abs_path), "%s/%s", dirname, filename);
144 status = lstat(abs_path, &statbuf);
145 if (status != 0) {
146 ERROR("cgroups plugin: stat (%s) failed.", abs_path);
147 return (-1);
148 }
150 if (S_ISDIR(statbuf.st_mode)) {
151 status = walk_directory(abs_path, read_cpuacct_procs,
152 /* user_data = */ NULL,
153 /* include_hidden = */ 0);
154 return (status);
155 }
157 return (0);
158 }
160 static int cgroups_init(void) {
161 if (il_cgroup == NULL)
162 il_cgroup = ignorelist_create(1);
164 return (0);
165 }
167 static int cgroups_config(const char *key, const char *value) {
168 cgroups_init();
170 if (strcasecmp(key, "CGroup") == 0) {
171 if (ignorelist_add(il_cgroup, value))
172 return (1);
173 return (0);
174 } else if (strcasecmp(key, "IgnoreSelected") == 0) {
175 if (IS_TRUE(value))
176 ignorelist_set_invert(il_cgroup, 0);
177 else
178 ignorelist_set_invert(il_cgroup, 1);
179 return (0);
180 }
182 return (-1);
183 }
185 static int cgroups_read(void) {
186 cu_mount_t *mnt_list = NULL;
187 _Bool cgroup_found = 0;
189 if (cu_mount_getlist(&mnt_list) == NULL) {
190 ERROR("cgroups plugin: cu_mount_getlist failed.");
191 return (-1);
192 }
194 for (cu_mount_t *mnt_ptr = mnt_list; mnt_ptr != NULL;
195 mnt_ptr = mnt_ptr->next) {
196 /* Find the cgroup mountpoint which contains the cpuacct
197 * controller. */
198 if ((strcmp(mnt_ptr->type, "cgroup") != 0) ||
199 !cu_mount_checkoption(mnt_ptr->options, "cpuacct", /* full = */ 1))
200 continue;
202 walk_directory(mnt_ptr->dir, read_cpuacct_root,
203 /* user_data = */ NULL,
204 /* include_hidden = */ 0);
205 cgroup_found = 1;
206 /* It doesn't make sense to check other cpuacct mount-points
207 * (if any), they contain the same data. */
208 break;
209 }
211 cu_mount_freelist(mnt_list);
213 if (!cgroup_found) {
214 WARNING("cgroups plugin: Unable to find cgroup "
215 "mount-point with the \"cpuacct\" option.");
216 return (-1);
217 }
219 return (0);
220 } /* int cgroup_read */
222 void module_register(void) {
223 plugin_register_config("cgroups", cgroups_config, config_keys,
224 config_keys_num);
225 plugin_register_init("cgroups", cgroups_init);
226 plugin_register_read("cgroups", cgroups_read);
227 } /* void module_register */