perf tools: Add read_cgroup_id() function

[linux-2.6-microblaze.git] / tools / perf / util / cgroup.c

diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
index f24ab45..ef18c98 100644 (file)
--- 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;