Laboratoire IRIT


An overview of my research work is available in my Habilitation (french) or in the associated slides (french)

My focus is on Energy Efficiency in ICT and with ICT. I mainly focuses on HPC and large scale infrastructures (clusters, grids, clouds). I'm associate professor in Sepia Team in IRIT Lab

Phd Students

Former Phd Students

Collaboration with Phd Students

Research Interests

Energy efficient task placement (centralized and decentralized)
Mathematical models of energy consumption
Green middleware for cluster/grid/cloud
Linux kernel governor for reducing HPC energy consumption
Energy consumption reduction in hybrid (Cpu/Gpu) architecture


Energumen Energy consumption has always been a concern in High Performance Computing (HPC) platforms. Today, it becomes even more critical due to the transition to the next generation extreme scale platforms. In ENERGUMEN, we propose two new complementary mechanisms for addressing the energy/performance trade-off: First, we will revisit the classical speed-scaling and power down mechanisms by using a malleable job model, which allows to shrink or stretch dynamically the execution times of the jobs according to the current energy profile. We will also study optimized policies for energy-aware data allocations at the software level. Both mechanisms involve the design of sophisticated models and methodologies for the efficient exploitation of the idle periods at running time. There are hard scientific and technological challenges to determine the best trade-off between both mechanisms. In the quest of extreme scale platforms where a trade-off between performance and energy consumption is necessary, the originality of ENERGUMEN is to revisit the principles of existing resource managers and to investigate new functionalities by harnessing applications' malleability.

neOCampus Action de l'universite Paul Sabatier neOCampus will demonstrate the campus of the future: connected, innovative, smart and sustainable.

COST IC-1305: Network for Sustainable Ultrascale Computing (NESUS) The goal of the NESUS Action is to establish an open European research network targeting sustainable solutions for ultrascale computing aiming at cross fertilization among HPC, large scale distributed systems, and big data management. The network will contribute to glue disparate researchers working across different areas and provide a meeting ground for researchers in these separate areas to exchange ideas, to identify synergies, and to pursue common activities in research topics such as sustainable software solutions (applications and system software stack), data management, energy efficiency, and resilience.

DataZero : Since some years energy efficiency in datacenters is improving but the amount of electricity needed for operating those for hosting Cloud services is growing with the sizes of the infrastructure and the user demands. With renewable energies and the usage of direct current in datacenters, we believe that we can cope with this problem. On the one hand several efforts have been conducted at the computing level in datacenters (for service placement and scheduling) and, on the other hand, for energy provisioning partly with renewable energies, but without much interaction between these two efforts. DATAZERO will give consistent solutions for high availability of IT (Information Technologies) services, avoiding unnecessary redundancies, under the constraints of intermittent nature of electrical and services flows. We noticed that, despite a true interest towards pragmatic and market-based solutions, comprehensive studies are missing to cope with the robustness of a cloud infrastructure in the conditions of datacenters powered by renewable energy. The question we address in DATAZERO is: How to manage the electricity and the service flows in order to deliver services to customers in a robust and efficient manner within datacenters operated with several energy sources?

PIXAL (2015-2016) : A new innovative platform for next generation teaching with interactive lessons, automatic evaluation of practical sessions and a nation-wide positioning test for computing science.

Finished projects

CoolEmAll (2011-2014) FP7 European project CoolEmAll will provide means for a deep insight into the total energy consumption of data centres. To this end, the project will provide advanced planning and optimization tools for modular data centre environments. Once developed, these tools should help to minimize the energy consumption, and consequently the CO2 emissions of the IT infrastructure with related facilities.

SOP: think global Services for persOnal comPuter (2011-2014) The objective of this ANR project is to build a hybrid working model for consumers and professional computing, that takes benefit from a mix between local installation/management and remote access to software and services located in distant dedicated datacenters or even in other non-used consumers’ machines

EcoToul (2012-2013)~: This projects aims at providing information concerning mobility in Toulouse. Data from thousands of smartphones users from several means of transportation (foot, bicycle, cars, public transports,...) will be merged in a global information systems. This data will be used to compute a transportation status map of Toulouse. This map will be used to give time of transit of several means of transportation to users.

COST IC-0804: Energy efficiency in large scale distributed systems (2009-2013) The main objective of the Action is to foster original research initiatives addressing energy awareness/saving and to increase the overall impact of European research in the field of energy efficiency in distributed systems. The goal of the Action is to give coherence to the European research agenda in the field, by promoting coordination and encouraging discussions among the individual research groups, sharing of operational know-how (lessons-learned, problems found during practical energy measurements and estimates, ideas for real-world exploitation of energy aware techniques, etc.)

ANR-JST FP3C (Framework and Programming for Post Petascale Computing) : French-Japanese Project on Petaflop applications (2010-2013) The goal of the project is to address the development of runtime systems for scientific applications running on petaflopic machines. Our contribution resides in the analysis of the energy consumption and leverages existing on such machines to handle their electricity hungriness.

PIREGRID: A Pyrenean Operational Grid (2009-2012) PireGrid is an INTERREG IV A project which have two main objectives: Deployment of a production Grid Computing infrastructure in the regions of Aragon, Aquitaine and Midi-Pyrenees. To achieve successful cases in execution of applications from small and medium size companies of these regions, in order to demonstrate its usage of these emerging technologies to the companies.

GreenNet (2008-2009) ARC Inria: Power aware software frameworks for high performance data transport and computing in large scale distributed systems

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