cgroupfs_find_mountpoint
int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys);
if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event") == 0)
if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))
if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event"))
if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))
if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event"))
if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, subsys))
if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX, "perf_event") < 0) {