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FoREST: FREquency Scaling Tool for Reactive DVFS control

FoREST is an innovative CPU DVFS controller developed at the University of Versailles, France. Its main goal is to efficiently control your CPU frequency in order to save energy.

FoREST is designed specifically to consider recent processor transformations. It targets multicore processors and features two working modes : energy and performance.

• In performance mode, FoREST tries to save as much energy as possible with a 5% performance degradation constraint.
• In energy mode, FoREST saves as much energy as possible with a 100% degradation constraint (2x slower).

It supports Intel SandyBridge and IvyBridge architectures, running on Linux 3.x kernels.

Experiments

FoREST gives significant energy savings on several benchmarks including the NAS OpenMP suite, when compared to regular Linux DVFS policies (ondemand, powersave) and other DVFS controllers (Granola, Beta-Adaptive). Results are shown in the following figures:

System energy savings compared to ondemand

FoREST can save significant amounts of energy at the system level compared to ondemand at nearly no cost on performance.

Execution time normalized over ondemand (1 means 100% of the execution time when using ondemand)

FoREST does not increase the execution time by more than 5% compared to ondemand.

Reference

• Reactive DVFS Control For Multicore Processors at IEEExplore (PrePrint PDF)

@INPROCEEDINGS{HPG13,
  author={Halimi, Jean-Philippe and Pradelle, Benoit and Guermouche, Amina and Triquenaux, Nicolas and Laurent, Alexandre and Beyler, Jean Christophe and Jalby, William},
  booktitle={Green Computing and Communications (GreenCom), 2013 IEEE and Internet of Things (iThings/CPSCom), IEEE International Conference on and IEEE Cyber, Physical and Social Computing}, 
  title={Reactive DVFS Control for Multicore Processors}, 
  year={2013},
  pages={102-109},
  keywords={DVFS;energy;frequency;runtime system},
  doi={10.1109/GreenCom-iThings-CPSCom.2013.41}
}