public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

perf tools: Add read_all_cgroups() and __cgroup_find()

Browse source 
The read_all_cgroups() is to build a tree of cgroups in the system and
users can look up a cgroup using __cgroup_find().

Committer notes:

Had to do this to cover that #else block:

  -static inline u64 __read_cgroup_id(const char *path) { return -1ULL; }
  +static inline u64 __read_cgroup_id(const char *path __maybe_unused) { return -1ULL; }

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230906174903.346486-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2023-09-06 10:48:59 -07:00 • committed by Arnaldo Carvalho de Melo
parent 36019dff30
commit 2bc12abce8
2 changed files with 57 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

61
tools/perf/util/cgroup.c
View file

@ -48,28 +48,36 @@ static int open_cgroup(const char *name)
}
#ifdef HAVE_FILE_HANDLE
int read_cgroup_id(struct cgroup *cgrp)
static u64 __read_cgroup_id(const char *path)
{
char path[PATH_MAX + 1];
char mnt[PATH_MAX + 1];
struct {
struct file_handle fh;
uint64_t cgroup_id;
} handle;
int mount_id;
handle.fh.handle_bytes = sizeof(handle.cgroup_id);
if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0)
return -1ULL;
return handle.cgroup_id;
}
int read_cgroup_id(struct cgroup *cgrp)
{
char path[PATH_MAX + 1];
char mnt[PATH_MAX + 1];
if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event"))
return -1;
scnprintf(path, PATH_MAX, "%s/%s", mnt, cgrp->name);
handle.fh.handle_bytes = sizeof(handle.cgroup_id);
if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0)
return -1;
cgrp->id = handle.cgroup_id;
cgrp->id = __read_cgroup_id(path);
return 0;
}
#else
static inline u64 __read_cgroup_id(const char *path __maybe_unused) { return -1ULL; }
#endif /* HAVE_FILE_HANDLE */
#ifndef CGROUP2_SUPER_MAGIC
@ -562,6 +570,11 @@ struct cgroup *cgroup__findnew(struct perf_env *env, uint64_t id,
return cgrp;
}
struct cgroup *__cgroup__find(struct rb_root *root, uint64_t id)
{
return __cgroup__findnew(root, id, /*create=*/false, /*path=*/NULL);
}
struct cgroup *cgroup__find(struct perf_env *env, uint64_t id)
{
struct cgroup *cgrp;
@ -587,3 +600,35 @@ void perf_env__purge_cgroups(struct perf_env *env)
}
up_write(&env->cgroups.lock);
}
void read_all_cgroups(struct rb_root *root)
{
char mnt[PATH_MAX];
struct cgroup_name *cn;
int prefix_len;
if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))
return;
/* cgroup_name will have a full path, skip the root directory */
prefix_len = strlen(mnt);
/* collect all cgroups in the cgroup_list */
if (nftw(mnt, add_cgroup_name, 20, 0) < 0)
return;
list_for_each_entry(cn, &cgroup_list, list) {
const char *name;
u64 cgrp_id;
/* cgroup_name might have a full path, skip the prefix */
name = cn->name + prefix_len;
if (name[0] == '\0')
name = "/";
cgrp_id = __read_cgroup_id(cn->name);
__cgroup__findnew(root, cgrp_id, /*create=*/true, name);
}
release_cgroup_list();
}

4
tools/perf/util/cgroup.h
View file

@ -37,6 +37,7 @@ int parse_cgroups(const struct option *opt, const char *str, int unset);
struct cgroup *cgroup__findnew(struct perf_env *env, uint64_t id,
const char *path);
struct cgroup *cgroup__find(struct perf_env *env, uint64_t id);
struct cgroup *__cgroup__find(struct rb_root *root, uint64_t id);
void perf_env__purge_cgroups(struct perf_env *env);
@ -49,6 +50,9 @@ static inline int read_cgroup_id(struct cgroup *cgrp __maybe_unused)
}
#endif /* HAVE_FILE_HANDLE */
/* read all cgroups in the system and save them in the rbtree */
void read_all_cgroups(struct rb_root *root);
int cgroup_is_v2(const char *subsys);
#endif /* __CGROUP_H__ */