/usr/lib/linux-tools/3.13.0-30-lowlatency/x86_energy_perf_policy is in linux-tools-3.13.0-30-lowlatency 3.13.0-30.55.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/3.13.0-30-lowlatency/../../linux-tools-3.13.0-30/x86_energy_perf_policy