Introduction
For a general explanation, check our webpage.
jRAPL works for three Intel architectures -- Sandy Bridge, Sandy Bridge_ep (Server) and Ivy Bridge. Each architecture has different RAPL support.
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Sandy Bridge/Ivy Bridge: GPU, CPU and package support.
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Sandy Bridge_ep: DRAM, CPU and package support.
You need check which one is your CPU architecture before you use jRAPL.
For more details about RAPL, check the main reference
Pre-requisites
This library uses the kernel msr module. To use, type
sudo modprobe msr
Build
To generate the library for JNI, type
make
How to use
Everytime you need root/sudo access to run the Java code in order to access RAPL MSR.
jRAPL includes the following methods, and it needs to be declared like the following before usage:
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public native static int ProfileInit();Initializes jRAPL. Just needs call once in the beginning. -
public native static String EnergyStatCheck();It returns a string value, which contains the format of content like:socket1_gpu/dram_energy#socket1_cpu_energy#socket1_package_energy@socket2_gpu/dram_energy#socket2_cpu_energy#socket2_package_energy. The character '#' seperates the energy information per the socket. Character '@' seperates different sockets. If it only has one socket, there is no '@'. -
public native static void ProfileDealloc();: Free the memory initialized inProfileInit().
The EnergyCheckUtils.java class provide a working sample on how to use jRAPL.
Known limitations
It only works for at most 2 sockets CPU.
Contributions
Want to contribute with code, documentation or bug report? That's great, check out the Issues page.
Contact
- Kenan Liu {kliu20@binghamton.edu}