Score-P libsensors Plugin Counter

This is a async plugin for Score-P to capture sensors available from hwmon. It utilizes the library libsensors for that.

Usage

The plugin is configure via environment variables. The following are available:

• SCOREP_METRIC_PLUGINS (required): Comma-separated list of enable plugins. MUST contain sensors_plugin.
• SCOREP_METRIC_SENSORS_PLUGIN (required): Comma-separated list of metrics to record. See below how to find available metrics.
• SCOREP_METRIC_SENSORS_PLUGIN_PERIOD (optional, default=1000000) Set the amplitude to read the sensors (in usecs).
• SCOREP_METRIC_SENSORS_PLUGIN_FILE (optional, default=none) Use the given alternate libsensors config-file. Only intended for experienced users.

Finding Available Metrics

The helper binary scorep-plugin-libsensors-print-sensors prints all available sensors. Copy the string From the second column to the environment variable SCOREP_METRIC_SENSORS_PLUGIN.

Example output:

$ ./result/bin/scorep-plugin-libsensors-print-sensors
Chip/Feature/Sub-feature;"SCOREP_METRIC_SENSORS_PLUGIN";current value
thinkpad//sys/class/hwmon/hwmon4/fan1/fan1_input;"thinkpad/fan1/fan1_input";0.000000e+00
thinkpad//sys/class/hwmon/hwmon4/fan2/fan2_input;"thinkpad/fan2/fan2_input";0.000000e+00
thinkpad//sys/class/hwmon/hwmon4/temp1/temp1_input;"thinkpad/CPU/temp1_input";5.600000e+01
[...]

Here, one might use export SCOREP_METRIC_SENSORS_PLUGIN="thinkpad/fan1/fan1_input,thinkpad/CPU/temp1_input"

To scan for available sensors, start the tool sensors-detect as root and follow the instructions on the screen. Use it at your own risk ;)

Sensor detection might not be necessary, depending on your system.

Compilation and Installation

Prerequisites

To compile this plugin, you need:

• C compiler
• libpthread
• Score-P
• libsensors (including development files)

Building

Ensure submodules are present. (execute git submodule update--init --recursive) Then follow standard cmake procedure.

mkdir build && cd build
cmake ..
make -j
make install

Append -DCMAKE_INSTALL_PREFIX=$PREFIX to set a different install prefix. Make sure that the installed libsensors_plugin.so is found by Score-P, e.g. by setting your LD_LIBRARY_PATH appropriately.

The following further build options can be set with -D<option>=<value> on cmake invocation:

• SENSORS_DIR (no default): directory to installed libsensors
• SENSORS_STATIC (default ON): whether to link against static libsensors.a (value ON) or dynamic libsensors.so (value OFF)
• BUILD_PRINT_SENSORS_BINARY (default ON): whether to build the helper binary to print available sensors

Further advanced options can be found in the source code.

Full Example Invocation

# Score-P configuration
export SCOREP_ENABLE_PROFILING=0
export SCOREP_ENABLE_TRACING=1
export SCOREP_TOTAL_MEMORY=4095M

# plugin configuration
export SCOREP_METRIC_PLUGINS=sensors_plugin
export SCOREP_METRIC_SENSORS_PLUGIN="thinkpad/fan1/fan1_input,thinkpad/CPU/temp1_input"

# sleep5 is an Score-P instrumented binary from the test/ subdirectory
SCOREP_EXPERIMENT_DIRECTORY=trace ./sleep5

# dump results
otf2-print trace/traces.otf

Testing

A simple script to check if the plugin is installed correctly resides in the subdirectory test/

Troubleshooting

1. Check whether the plugin library can be loaded from the LD_LIBRARY_PATH.
2. It may be, that libsensors needs root access to read the counters. In this case, you need to trace your application as root. Alternatively, attempt to allow non-root users to read your sensors by setting sudo sysctl kernel.perf_event_paranoid=-1.
3. The maximum number of counters is defined in the source file. Adapt MAX_SENSOR_COUNTER to en- or decrease it and recompile the plugin.
4. Open an issue or send an E-Mail to the author.

Authors

• Robert Schoene (robert.schoene at tu-dresden dot de)