blob: 03347748f3fadc43f070fa0b6ef789f071c30d65 [file] [log] [blame]
Stephane Eranian023695d2011-02-14 11:20:01 +02001#include "util.h"
2#include "../perf.h"
Josh Poimboeuf4b6ab942015-12-15 09:39:39 -06003#include <subcmd/parse-options.h>
Stephane Eranian023695d2011-02-14 11:20:01 +02004#include "evsel.h"
5#include "cgroup.h"
Stephane Eranian023695d2011-02-14 11:20:01 +02006#include "evlist.h"
Arnaldo Carvalho de Meloaa8cc2f2017-04-17 15:36:40 -03007#include <linux/stringify.h>
Stephane Eranian023695d2011-02-14 11:20:01 +02008
9int nr_cgroups;
10
11static int
12cgroupfs_find_mountpoint(char *buf, size_t maxlen)
13{
14 FILE *fp;
Arnaldo Carvalho de Meloc168fbf2011-11-16 12:55:59 -020015 char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
Tejun Heo968ebff2017-01-29 14:35:20 -050016 char path_v1[PATH_MAX + 1], path_v2[PATH_MAX + 2], *path;
Eric Dumazet621d2652011-04-08 12:11:06 +020017 char *token, *saved_ptr = NULL;
Stephane Eranian023695d2011-02-14 11:20:01 +020018
19 fp = fopen("/proc/mounts", "r");
20 if (!fp)
21 return -1;
22
23 /*
24 * in order to handle split hierarchy, we need to scan /proc/mounts
25 * and inspect every cgroupfs mount point to find one that has
26 * perf_event subsystem
27 */
Tejun Heo968ebff2017-01-29 14:35:20 -050028 path_v1[0] = '\0';
29 path_v2[0] = '\0';
30
Arnaldo Carvalho de Meloaa8cc2f2017-04-17 15:36:40 -030031 while (fscanf(fp, "%*s %"__stringify(PATH_MAX)"s %"__stringify(PATH_MAX)"s %"
32 __stringify(PATH_MAX)"s %*d %*d\n",
Stephane Eranian023695d2011-02-14 11:20:01 +020033 mountpoint, type, tokens) == 3) {
34
Tejun Heo968ebff2017-01-29 14:35:20 -050035 if (!path_v1[0] && !strcmp(type, "cgroup")) {
Stephane Eranian023695d2011-02-14 11:20:01 +020036
37 token = strtok_r(tokens, ",", &saved_ptr);
38
39 while (token != NULL) {
40 if (!strcmp(token, "perf_event")) {
Tejun Heo968ebff2017-01-29 14:35:20 -050041 strcpy(path_v1, mountpoint);
Stephane Eranian023695d2011-02-14 11:20:01 +020042 break;
43 }
44 token = strtok_r(NULL, ",", &saved_ptr);
45 }
46 }
Tejun Heo968ebff2017-01-29 14:35:20 -050047
48 if (!path_v2[0] && !strcmp(type, "cgroup2"))
49 strcpy(path_v2, mountpoint);
50
51 if (path_v1[0] && path_v2[0])
Stephane Eranian023695d2011-02-14 11:20:01 +020052 break;
53 }
54 fclose(fp);
Tejun Heo968ebff2017-01-29 14:35:20 -050055
56 if (path_v1[0])
57 path = path_v1;
58 else if (path_v2[0])
59 path = path_v2;
60 else
Stephane Eranian023695d2011-02-14 11:20:01 +020061 return -1;
62
Tejun Heo968ebff2017-01-29 14:35:20 -050063 if (strlen(path) < maxlen) {
64 strcpy(buf, path);
Stephane Eranian023695d2011-02-14 11:20:01 +020065 return 0;
66 }
67 return -1;
68}
69
70static int open_cgroup(char *name)
71{
Arnaldo Carvalho de Meloc168fbf2011-11-16 12:55:59 -020072 char path[PATH_MAX + 1];
73 char mnt[PATH_MAX + 1];
Stephane Eranian023695d2011-02-14 11:20:01 +020074 int fd;
75
76
Arnaldo Carvalho de Meloc168fbf2011-11-16 12:55:59 -020077 if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1))
Stephane Eranian023695d2011-02-14 11:20:01 +020078 return -1;
79
Arnaldo Carvalho de Meloc168fbf2011-11-16 12:55:59 -020080 snprintf(path, PATH_MAX, "%s/%s", mnt, name);
Stephane Eranian023695d2011-02-14 11:20:01 +020081
82 fd = open(path, O_RDONLY);
83 if (fd == -1)
84 fprintf(stderr, "no access to cgroup %s\n", path);
85
86 return fd;
87}
88
89static int add_cgroup(struct perf_evlist *evlist, char *str)
90{
91 struct perf_evsel *counter;
92 struct cgroup_sel *cgrp = NULL;
93 int n;
94 /*
95 * check if cgrp is already defined, if so we reuse it
96 */
Arnaldo Carvalho de Meloe5cadb92016-06-23 11:26:15 -030097 evlist__for_each_entry(evlist, counter) {
Stephane Eranian023695d2011-02-14 11:20:01 +020098 cgrp = counter->cgrp;
99 if (!cgrp)
100 continue;
101 if (!strcmp(cgrp->name, str))
102 break;
103
104 cgrp = NULL;
105 }
106
107 if (!cgrp) {
108 cgrp = zalloc(sizeof(*cgrp));
109 if (!cgrp)
110 return -1;
111
112 cgrp->name = str;
113
114 cgrp->fd = open_cgroup(str);
115 if (cgrp->fd == -1) {
116 free(cgrp);
117 return -1;
118 }
119 }
120
121 /*
122 * find corresponding event
123 * if add cgroup N, then need to find event N
124 */
125 n = 0;
Arnaldo Carvalho de Meloe5cadb92016-06-23 11:26:15 -0300126 evlist__for_each_entry(evlist, counter) {
Stephane Eranian023695d2011-02-14 11:20:01 +0200127 if (n == nr_cgroups)
128 goto found;
129 n++;
130 }
Elena Reshetova79c5fe62017-02-21 17:34:55 +0200131 if (refcount_read(&cgrp->refcnt) == 0)
Stephane Eranian023695d2011-02-14 11:20:01 +0200132 free(cgrp);
133
134 return -1;
135found:
Elena Reshetova79c5fe62017-02-21 17:34:55 +0200136 refcount_inc(&cgrp->refcnt);
Stephane Eranian023695d2011-02-14 11:20:01 +0200137 counter->cgrp = cgrp;
138 return 0;
139}
140
141void close_cgroup(struct cgroup_sel *cgrp)
142{
Elena Reshetova79c5fe62017-02-21 17:34:55 +0200143 if (cgrp && refcount_dec_and_test(&cgrp->refcnt)) {
Stephane Eranian023695d2011-02-14 11:20:01 +0200144 close(cgrp->fd);
Arnaldo Carvalho de Melo74cf2492013-12-27 16:55:14 -0300145 zfree(&cgrp->name);
Stephane Eranian023695d2011-02-14 11:20:01 +0200146 free(cgrp);
147 }
148}
149
Irina Tirdea1d037ca2012-09-11 01:15:03 +0300150int parse_cgroups(const struct option *opt __maybe_unused, const char *str,
151 int unset __maybe_unused)
Stephane Eranian023695d2011-02-14 11:20:01 +0200152{
153 struct perf_evlist *evlist = *(struct perf_evlist **)opt->value;
154 const char *p, *e, *eos = str + strlen(str);
155 char *s;
156 int ret;
157
158 if (list_empty(&evlist->entries)) {
159 fprintf(stderr, "must define events before cgroups\n");
160 return -1;
161 }
162
163 for (;;) {
164 p = strchr(str, ',');
165 e = p ? p : eos;
166
167 /* allow empty cgroups, i.e., skip */
168 if (e - str) {
169 /* termination added */
170 s = strndup(str, e - str);
171 if (!s)
172 return -1;
173 ret = add_cgroup(evlist, s);
174 if (ret) {
175 free(s);
176 return -1;
177 }
178 }
179 /* nr_cgroups is increased een for empty cgroups */
180 nr_cgroups++;
181 if (!p)
182 break;
183 str = p+1;
184 }
185 return 0;
186}