gnarlie / counter-metrics

Read and report Intel performan e counters

What's This?

This is a simple demonstration of using the Intel built-in perf counters. The basic idea is to create one or more PerfCounter objects before doing something "interesting", and read the value() afterward, perhaps logging unusally high events or aggregating readings over time.

Getting it to work

For a Linux server, make sure the following configuration allows reading performance counters from user mode:

• /proc/sys/kernel/perf_event_paranoid: set to -1 or 0
• /sys/devices/cpu/rdpmc: set to 2, newer kernels only

To make Google benchmark happy, you'll want to disable cpu scaling. cpupower frequency-set -g performance

Run the sample with:

./benchy --benchmark_counters_tabular=true

Trouble?

munmap(_meta, pgsz) returned Invalid argument

Double check /proc/sys/kernel/perf_event_paranoid is set to -1