sample_rapl.sh

#!/usr/bin/env bash
#
# Bash script to sample Intel RAPL inteface and save numbers to a file.
# This script will run until manually interrupted.
#
# The CPU_POWER_OUTPUT_FILE environment variable must be set before
# running this script.

# Make sure CPU_POWER_OUTPUT_FILE variable is defined
set -u
: "$CPU_POWER_OUTPUT_FILE"

# Sampling cadence in seconds
CADENCE="0.1"
COUNTER="/sys/class/powercap/intel-rapl/intel-rapl:0/energy_uj"

echo "Sampling $COUNTER" >> $CPU_POWER_OUTPUT_FILE
echo "Cadence = $CADENCE seconds" >> $CPU_POWER_OUTPUT_FILE

while /bin/true; do
    RAPL=$(cat $COUNTER)
    TIME=$(date --iso-8601=ns)
    echo "$TIME, $RAPL" >> $CPU_POWER_OUTPUT_FILE
    sleep $CADENCE
done