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authorNamhyung Kim <namhyung@kernel.org>2021-06-25 10:18:23 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-07-01 21:00:03 +0300
commit69e874db4dded0f2fe56ae623d7f54318395c87d (patch)
treefcbf8fe8a13cbd71508aeac140d71399d86f0c94 /tools/perf/util/cgroup.c
parentf20510d552e2941df2518c73c99fa2537575dbce (diff)
downloadlinux-69e874db4dded0f2fe56ae623d7f54318395c87d.tar.xz
perf tools: Add read_cgroup_id() function
The read_cgroup_id() is to read a cgroup id from a file handle using name_to_handle_at(2) for the given cgroup. It'll be used by bperf cgroup stat later. Committer notes: -int read_cgroup_id(struct cgroup *cgrp) +static inline int read_cgroup_id(struct cgroup *cgrp __maybe_unused) To fix the build when HAVE_FILE_HANDLE is not defined. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20210625071826.608504-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/cgroup.c')
-rw-r--r--tools/perf/util/cgroup.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
index f24ab4585553..ef18c988c681 100644
--- a/tools/perf/util/cgroup.c
+++ b/tools/perf/util/cgroup.c
@@ -45,6 +45,31 @@ static int open_cgroup(const char *name)
return fd;
}
+#ifdef HAVE_FILE_HANDLE
+int read_cgroup_id(struct cgroup *cgrp)
+{
+ char path[PATH_MAX + 1];
+ char mnt[PATH_MAX + 1];
+ struct {
+ struct file_handle fh;
+ uint64_t cgroup_id;
+ } handle;
+ int mount_id;
+
+ 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;
+ return 0;
+}
+#endif /* HAVE_FILE_HANDLE */
+
static struct cgroup *evlist__find_cgroup(struct evlist *evlist, const char *str)
{
struct evsel *counter;