CPU Energy Package - RAPL Component

What it does#

This metric provider reads the energy of the CPU Package from the Running Average Power Limit (RAPL) interface via a machine specific register (MSR) that is present on most modern Intel and AMD processors. In depth information about RAPL can be found in the Intel Software Developer Manual.

This MSR keeps a running count of the energy used in a specified domain in microJoules. This metric provider specifically reads from the energy-pkg domain, which gives you the cumulatove energy used by the domains energy-cores, energy-gpu and some extra parts like the voltage regulator and such that also reside on the package.

Setup#

Please look at RAPL installation

Technical specs#

• Time resolution: up to 976 micro-seconds (depending on production year of the CPU)
• Energy resolution: up to 15.3 micro-Joules (depending on production year of the CPU)

Classname#

• CpuEnergyRaplMsrComponentProvider

Metric Name#

• cpu_energy_rapl_msr_component

Input Parameters#

• Args:
  • i: specifies interval in milliseconds between measurements

./metric-provider-binary -i 100

Output#

This metric provider prints to Stdout a continuous stream of data. The format of the data is as follows:

TIMESTAMP ENERGY_OUTPUT

Where:

• TIMESTAMP: Unix timestamp, in microseconds
• ENERGY_OUTPUT: Energy used during interval, in micro Joules
• PACKAGE_ID: ID of the package in case you have multiple CPU chips installed. Otherwise always Package_0

Example output:

1712641603443421 8092 Package_0
1712641604443831 8047 Package_0
.....

Any errors are printed to Stderr.

How it works#

We use a modified version of the open source code found here: (github)

First we check if the CPU is compatible by reading the cpu info from /proc/cpuinfo. Supported are Intel CPUs of family 6 and AMD CPUs of family 17h / 19h. On AMD the RAPL MSRs live at different addresses, which the provider selects automatically.

The following CPU models are known to the provider:

CPU_SANDYBRIDGE, CPU_SANDYBRIDGE_EP, CPU_IVYBRIDGE, CPU_IVYBRIDGE_EP, CPU_HASWELL, CPU_HASWELL_ULT, CPU_HASWELL_GT3E, CPU_HASWELL_EP, CPU_BROADWELL, CPU_BROADWELL_GT3E, CPU_BROADWELL_EP, CPU_BROADWELL_DE, CPU_SKYLAKE, CPU_SKYLAKE_HS, CPU_SKYLAKE_X, CPU_KNIGHTS_LANDING, CPU_KNIGHTS_MILL, CPU_KABYLAKE_MOBILE, CPU_KABYLAKE, CPU_ATOM_SILVERMONT, CPU_ATOM_AIRMONT, CPU_ATOM_MERRIFIELD, CPU_ATOM_MOOREFIELD, CPU_ATOM_GOLDMONT, CPU_ATOM_GEMINI_LAKE, CPU_ATOM_DENVERTON, CPU_TIGER_LAKE, CPU_AMD_FAM17H

It reads the values from /dev/cpu/%d/msr

Note that since it reads the energy used by the entire system, any other load that your system has during a program’s usage run will also be captured in the energy measurement.