Open
Description
On some system, the sensor fails to access RAPL counters and we get this error at startup:
E: 21-12-07 11:14:26 config: event 'RAPL_ENERGY_PKG' is invalid or unsupported by this machine
However, on the same systems, we can see rapl data in the powercap sysfs.
powerapi-ng/powerapi#125 is probably an example of such error.
Actually the sensor use the perf subsystem to access rapl, which is implemented in a different part of the kernel source tree than powercap. Thus I suspect that this can happens when the kernel contains, for the cpu of the machine, the implementation of powercap but not of rapl access in perf.
I suggest we implement a fallback access to RAPL using powercap sysfs, when we cannot use perf.