X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/mpi-energy2.git/blobdiff_plain/5deb7a6421f3db1ad3f71e650dc398a1bd3801a9..e71f2efd5963df24a527e596ea349077f0c0055b:/mpi-energy2-extension/Heter_paper.tex?ds=sidebyside diff --git a/mpi-energy2-extension/Heter_paper.tex b/mpi-energy2-extension/Heter_paper.tex index e42e76e..ef4982b 100644 --- a/mpi-energy2-extension/Heter_paper.tex +++ b/mpi-energy2-extension/Heter_paper.tex @@ -97,7 +97,7 @@ Tianhe-2 had the highest FLOPS in June 2015 according to the Top500 list \cite{TOP500_Supercomputers_Sites}. However, it was also the most power hungry platform with its over 3 million cores consuming around 17.8 megawatts. Moreover, according to the U.S. annual energy outlook 2015 -\cite{U.S_Annual.Energy.Outlook.2014}, the price of energy for 1 megawatt-hour +\cite{U.S_Annual.Energy.Outlook.2015}, the price of energy for 1 megawatt-hour was approximately equal to \$70. Therefore, the price of the energy consumed by the Tianhe-2 platform is approximately more than \$10 million each year. The computing platforms must be more energy efficient and offer the highest number @@ -107,6 +107,7 @@ This heterogeneous platform executes more than 7 GFLOPS per watt while consuming 50.32 kilowatts. } +\textcolor{blue}{ Besides platform improvements, there are many software and hardware techniques to lower the energy consumption of these platforms, such as scheduling, DVFS, \dots{} DVFS is a widely used process to reduce the energy consumption of a @@ -120,12 +121,14 @@ trade-off between the energy reduction and performance degradation ratio. In the energy consumption of message passing iterative applications running over homogeneous and heterogeneous clusters respectively. The results of the experiments show significant energy -consumption reductions. In this paper, a new frequency selecting algorithm -adapted for heterogeneous platform is presented. It selects the vector of +consumption reductions. All the experimental results were conducted over +Simgrid simulator \cite{SimGrid}, which offers easy tools to create a homogeneous and heterogeneous platforms. In this paper, a new frequencies selecting algorithm +adapted for heterogeneous grid platform is presented and executed over real testbed, +the grid'5000 platform \cite{grid5000}. It selects the vector of frequencies, for a heterogeneous grid platform running a message passing iterative application, that simultaneously tries to offer the maximum energy reduction and minimum performance degradation ratio. The algorithm has a very small overhead, -works online and does not need any training or profiling. +works online and does not need any training or profiling.} \textcolor{blue}{ This paper is organized as follows: Section~\ref{sec.relwork} presents some @@ -443,12 +446,15 @@ appropriate frequency scaling factor for each processor while considering the characteristics of each processor (computation power, range of frequencies, dynamic and static powers) and the task executed (computation/communication ratio). The aim being to reduce the overall energy consumption and to avoid -increasing significantly the execution time. In our previous -work~\cite{Our_first_paper,pdsec2015}, we proposed a method that selects the optimal -frequency scaling factor for a homogeneous and heterogeneous clusters executing a message passing +increasing significantly the execution time. +\textcolor{blue}{ In our previous +works~\cite{Our_first_paper} and \cite{pdsec2015}, we proposed a methods that select the optimal +frequency scaling factors for a homogeneous and a heterogeneous clusters respectively. +Both of the two methods executing a message passing iterative synchronous application while giving the best trade-off between the energy consumption and the performance for such applications. In this work we -are interested in heterogeneous grid as described above. Due to the +are interested in heterogeneous grid as described above.} +Due to the heterogeneity of the processors, a vector of scaling factors should be selected and it must give the best trade-off between energy consumption and performance.