PowerTOP is not working on Brickland-EX/Haswell-EX system with following error msg displayed: root@localhost:~# powertop Cannot load from file /var/cache/powertop/saved_results.powertop Cannot load from file /var/cache/powertop/saved_parameters.powertop RAPL device for cpu 0 RAPL device for cpu 0 RAPL device for cpu 18 RAPL device for cpu 18 RAPL device for cpu 36 RAPL device for cpu 36 RAPL device for cpu 54 RAPL device for cpu 54 RAPL device for cpu 0 Cannot load from file /var/cache/powertop/saved_parameters.powertop PowerTOP v2.4 needs the kernel to support the 'perf' subsystem as well as support for trace points in the kernel: CONFIG_PERF_EVENTS=y CONFIG_PERF_COUNTERS=y CONFIG_TRACEPOINTS=y bits physical, 48 bits virtual CONFIG_TRACING=y:
