Sensor plugins are plugins used to retreive the energy consumption of the hardware. They are different type of sensor plugins as there are different kind of hardware on which we can retreive energy consumption. In this version of vJoule, there are cpu, ram and gpu plugins implemented.

Information about the plugins can be retreived by running the command :

# vjoule_service --ph plugin_name
# for example

$ vjoule_service --ph rapl

The rapl plugin retreive the energy consumption of three kind of hardware, cpu, ram and gpu where here the gpu is the integrated gpu chip. RAPL is usable on intel cores only.

Depending on the machine, gpu and ram may be unavailable, in that case during the configuration warnings will be displayed, and ram and gpu energy consumption retreiving will always return 0.

Warning, there is no perf events on integrated GPU, meaning that the gpu consumption will be acquired for the whole system but will not be divided between cgroups when using the divider core plugin.

The nvidia plugin retreives the consumption of nvidia graphics card using nvml. It can be only be used for the component gpu. This plugin takes only one element of configuration cgroup-consumption.

[gpu]
name = "nvidia"
cgroup-consumption = true

If cgroup-consumption is true, then the plugin will retreive the name of the cgroups using the device, and their percentage of usage. Depending on the graphics card, cgroup usage can be available or not. Warning messages are displayed if it is not available. The plugin is capable of managing multiple devices, if multiple graphics card are found on the machine.

When there are a nvidia GPU, there can still be an integrated intel GPU. In that case multiple GPUs consumption are retreivable. To define that in the configuration file, the following can be written.

[gpu:0]
name = "rapl"

[gpu:1]
name = "nvidia"

Both divider and dumper cores are able to manage multiple gpu plugins, but only one cpu and one ram plugin can be used at the same time.