of_peak
struct cgroup_of_peak *of_peak(struct kernfs_open_file *of);
struct cgroup_of_peak *ofp = of_peak(sf->private);
struct cgroup_of_peak *ofp = of_peak(of);
struct cgroup_of_peak *ofp = of_peak(of);
struct cgroup_of_peak *ofp = of_peak(of);