X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/mpi-energy2.git/blobdiff_plain/7f9ca96425114b39b06dc8c85ff608e87facf26f..5a4042c6601918367a8178fafff59c04b2f4f9c8:/mpi-energy2-extension/Heter_paper.tex?ds=inline

diff --git a/mpi-energy2-extension/Heter_paper.tex b/mpi-energy2-extension/Heter_paper.tex
index f00d065..c8f4cd0 100644
--- a/mpi-energy2-extension/Heter_paper.tex
+++ b/mpi-energy2-extension/Heter_paper.tex
@@ -115,7 +115,7 @@
 
 \section{Introduction}
 \label{sec.intro}
-\textcolor{blue}{
+\textcolor{red}{did you verify that these informations are still accurate before changing the years to 2015?}
 The need for more computing power is continually increasing. To partially
 satisfy this need, most supercomputers constructors just put more computing
 nodes in their platform. The resulting platforms may achieve higher floating
@@ -133,9 +133,7 @@ of FLOPS per watt possible, such as the Shoubu-ExaScaler from RIKEN
 which became the top of the Green500 list in June 2015 \cite{Green500_List}.
 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
@@ -148,32 +146,31 @@ trade-off between the energy reduction and performance degradation ratio. In
 \cite{Our_first_paper} and \cite{pdsec2015} , a frequencies selecting algorithm was proposed to reduce
 the energy consumption of message passing iterative applications running over
 homogeneous  and heterogeneous clusters respectively.  
-The results of the experiments show significant energy
+The results of the experiments showed significant energy
 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.}
+Simgrid simulator \cite{SimGrid}, which offers easy tools to create a homogeneous and heterogeneous platforms and run message passing parallel applications over them. In this paper, a new frequencies selecting algorithm,
+adapted to  grid platforms, is presented. It is applied to the NAS parallel benchmarks and evaluated over a real testbed, 
+the grid'5000 platform \cite{grid5000}. It selects  for a grid platform running a message passing iterative
+application the vector of
+frequencies  that simultaneously tries to offer the maximum energy reduction and
+minimum performance degradation ratios. The algorithm has a very small overhead,
+works online and does not need any training or profiling.
+
 
-\textcolor{blue}{
 This paper is organized as follows: Section~\ref{sec.relwork} presents some
 related works from other authors.  Section~\ref{sec.exe} describes how the
 execution time of message passing programs can be predicted.  It also presents
 an energy model that predicts the energy consumption of an application running
-over a heterogeneous grid. Section~\ref{sec.compet} presents the
+over a grid platform. Section~\ref{sec.compet} presents the
 energy-performance objective function that maximizes the reduction of energy
 consumption while minimizing the degradation of the program's performance.
 Section~\ref{sec.optim} details the proposed frequencies selecting algorithm.
 Section~\ref{sec.expe} presents the results of applying the algorithm on the 
-NAS parallel benchmarks and executing them on a grid'5000 testbed. 
+NAS parallel benchmarks and executing them on the grid'5000 testbed. 
 It shows the results of running different scenarios using multi-cores and one core per node 
-and comparing them. It also shows the results of running
-three different power scenarios and comparing them. Moreover, it shows the
+and comparing them. It also evaluates the algorithm over three different power scenarios. Moreover, it shows the
 comparison results between the proposed method and an existing method.  Finally,
-in Section~\ref{sec.concl} the paper ends with a summary and some future works.}
+in Section~\ref{sec.concl} the paper ends with a summary and some future works.
 
 \section{Related works}
 \label{sec.relwork}
@@ -1205,8 +1202,8 @@ distance percentages for the these static power scenarios are not significantly
 
 Finding the frequencies that gives the best tradeoff between the energy consumption and the performance for a parallel 
 application is not a trivial task.  Many algorithms have been proposed to tackle this problem.  
-In this section, the proposed frequencies selecting algorithm is compared to well known  energy and delay product method, $EDP=energy \times delay$, that have been used by many researchers  \cite{EDP_for_multi_processors,Energy_aware_application_scheduling,Exploring_Energy_Performance_TradeOffs}. 
-This method  was also used by Spiliopoulos et al. algorithm \cite{Spiliopoulos_Green.governors.Adaptive.DVFS} where they select the frequencies that minimize the EDP product and apply them with DVFS operations to  the multi-cores 
+In this section, the proposed frequencies selecting algorithm is compared to a method that uses the well known  energy and delay product objective function, $EDP=energy \times delay$, that has been used by many researchers  \cite{EDP_for_multi_processors,Energy_aware_application_scheduling,Exploring_Energy_Performance_TradeOffs}. 
+This objective function  was also used by Spiliopoulos et al. algorithm \cite{Spiliopoulos_Green.governors.Adaptive.DVFS} where they select the frequencies that minimize the EDP product and apply them with DVFS operations to  the multi-cores 
 architecture. Their online algorithm predicts the energy consumption and execution time of a processor before using the EDP method.
 
 To fairly compare the proposed frequencies scaling algorithm to  Spiliopoulos et al. algorithm, called Maxdist and EDP respectively, both algorithms use the same energy model,  equation \ref{eq:energy} and
@@ -1257,37 +1254,36 @@ maximum number of available frequencies. When Maxdist is applied to a benchmark
 
 \section{Conclusion}
 \label{sec.concl}
-\textcolor{blue}{
-This paper has been  presented a new online frequencies selection algorithm.
-It works based on objective function that maximized the tradeoff distance 
+This paper has presented a new online frequencies selection algorithm.
+ The algorithm selects the best vector of 
+frequencies that maximizes  the tradeoff distance 
 between the predicted energy consumption and the predicted execution time of the distributed 
-iterative applications running over heterogeneous grid. The algorithm selects the best vector of the 
-frequencies which maximized the objective function has been used. A new energy model 
-used by the proposed algorithm for measuring and predicting the energy consumption 
-of the distributed iterative message passing application running over grid architecture.
+iterative applications running over a heterogeneous grid. A new energy model 
+is used by the proposed algorithm to predict the energy consumption 
+of the distributed iterative message passing application running over a grid architecture.
 To evaluate the proposed method on a real heterogeneous grid platform, it was applied on the  
-NAS parallel benchmarks  class D instance  and executed over grid'5000 testbed platform. 
-The experimental results showed that the algorithm saves the energy consumptions on average 
-for all NAS benchmarks up to 30\%  while gives only 3\% percentage on average for the performance 
-degradation for the same instance. The algorithm also selecting different frequencies according to the 
-computations and communication times ratio, and according to the values of the static and measured dynamic power of the CPUs. The computations to communications ratio was varied between different scenarios have been used, concerning to the distribution of the computing nodes between different clusters' sites and using one core or multi-cores per node.
-Finally, the proposed algorithm was compared to other algorithm which it
-used the will known energy and delay product as an objective function. The comparison results showed 
-that the proposed algorithm outperform the other one in term of energy-time tradeoff.
+ NAS parallel benchmarks   and the  class D instance was executed over the  grid'5000 testbed platform. 
+ The experimental results showed that the algorithm reduces  on average 30\% of the energy consumption
+for all the NAS benchmarks   while  only degrading by 3\% on average  the performance. 
+The Maxdist algorithm was also evaluated in different scenarios that vary in the distribution of the computing nodes between different clusters' sites,  use one core or multi-cores per node or assume different values for the consumed static power. The algorithm selects different vector of frequencies according to the 
+computations and communication times ratios, and  the values of the static and measured dynamic powers of the CPUs. 
+Finally, the proposed algorithm was compared to another method that uses
+the well known energy and delay product as an objective function. The comparison results showed 
+that the proposed algorithm outperforms the latter by selecting a vector of frequencies that gives a better tradeoff  between energy consumption reduction and performance. 
+
 In the near future, we would like to develop a similar method that is adapted to
-asynchronous iterative applications where each task does not
-wait for other tasks to finish their works. The development of
+asynchronous iterative applications where iterations are not synchronized and communications are overlapped with computations. 
+ The development of
 such a method might require a new energy model because the
 number of iterations is not known in advance and depends on
 the global convergence of the iterative system.
-}
+
 
 
 \section*{Acknowledgment}
 
 This work  has been  partially supported by  the Labex ACTION  project (contract
-``ANR-11-LABX-01-01'').  Computations  have been performed  on the supercomputer
-facilities  of the  MÃ©socentre de  calcul de  Franche-ComtÃ©. As  a  PhD student,
+``ANR-11-LABX-01-01'').  Computations  have been performed  on the Grid'5000 platform. As  a  PhD student,
 Mr. Ahmed  Fanfakh, would  like to  thank the University  of Babylon  (Iraq) for
 supporting his work.
 
