]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - tools/perf/util/cgroup.c
3 #include <subcmd/parse-options.h>
7 #include <linux/stringify.h>
12 cgroupfs_find_mountpoint(char *buf
, size_t maxlen
)
15 char mountpoint
[PATH_MAX
+ 1], tokens
[PATH_MAX
+ 1], type
[PATH_MAX
+ 1];
16 char path_v1
[PATH_MAX
+ 1], path_v2
[PATH_MAX
+ 2], *path
;
17 char *token
, *saved_ptr
= NULL
;
19 fp
= fopen("/proc/mounts", "r");
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
31 while (fscanf(fp
, "%*s %"__stringify(PATH_MAX
)"s %"__stringify(PATH_MAX
)"s %"
32 __stringify(PATH_MAX
)"s %*d %*d\n",
33 mountpoint
, type
, tokens
) == 3) {
35 if (!path_v1
[0] && !strcmp(type
, "cgroup")) {
37 token
= strtok_r(tokens
, ",", &saved_ptr
);
39 while (token
!= NULL
) {
40 if (!strcmp(token
, "perf_event")) {
41 strcpy(path_v1
, mountpoint
);
44 token
= strtok_r(NULL
, ",", &saved_ptr
);
48 if (!path_v2
[0] && !strcmp(type
, "cgroup2"))
49 strcpy(path_v2
, mountpoint
);
51 if (path_v1
[0] && path_v2
[0])
63 if (strlen(path
) < maxlen
) {
70 static int open_cgroup(char *name
)
72 char path
[PATH_MAX
+ 1];
73 char mnt
[PATH_MAX
+ 1];
77 if (cgroupfs_find_mountpoint(mnt
, PATH_MAX
+ 1))
80 snprintf(path
, PATH_MAX
, "%s/%s", mnt
, name
);
82 fd
= open(path
, O_RDONLY
);
84 fprintf(stderr
, "no access to cgroup %s\n", path
);
89 static int add_cgroup(struct perf_evlist
*evlist
, char *str
)
91 struct perf_evsel
*counter
;
92 struct cgroup_sel
*cgrp
= NULL
;
95 * check if cgrp is already defined, if so we reuse it
97 evlist__for_each_entry(evlist
, counter
) {
101 if (!strcmp(cgrp
->name
, str
)) {
102 refcount_inc(&cgrp
->refcnt
);
110 cgrp
= zalloc(sizeof(*cgrp
));
115 refcount_set(&cgrp
->refcnt
, 1);
117 cgrp
->fd
= open_cgroup(str
);
118 if (cgrp
->fd
== -1) {
125 * find corresponding event
126 * if add cgroup N, then need to find event N
129 evlist__for_each_entry(evlist
, counter
) {
134 if (refcount_dec_and_test(&cgrp
->refcnt
))
139 counter
->cgrp
= cgrp
;
143 void close_cgroup(struct cgroup_sel
*cgrp
)
145 if (cgrp
&& refcount_dec_and_test(&cgrp
->refcnt
)) {
152 int parse_cgroups(const struct option
*opt __maybe_unused
, const char *str
,
153 int unset __maybe_unused
)
155 struct perf_evlist
*evlist
= *(struct perf_evlist
**)opt
->value
;
156 const char *p
, *e
, *eos
= str
+ strlen(str
);
160 if (list_empty(&evlist
->entries
)) {
161 fprintf(stderr
, "must define events before cgroups\n");
166 p
= strchr(str
, ',');
169 /* allow empty cgroups, i.e., skip */
171 /* termination added */
172 s
= strndup(str
, e
- str
);
175 ret
= add_cgroup(evlist
, s
);
181 /* nr_cgroups is increased een for empty cgroups */