From: jccharr Date: Tue, 28 Oct 2014 14:40:57 +0000 (+0100) Subject: section IV corrected X-Git-Tag: pdsec15_submission~94 X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/mpi-energy2.git/commitdiff_plain/a88840386a8fd302d0460659690d13732a9f3a38?ds=inline section IV corrected --- diff --git a/Heter_paper.tex b/Heter_paper.tex index c6f3021..8c329a8 100644 --- a/Heter_paper.tex +++ b/Heter_paper.tex @@ -267,20 +267,25 @@ In the same way, we normalize the energy by computing the ratio between the cons \end{multline} Where $T_{New}$ and $T_{Old}$ are computed as in EQ(\ref{eq:pnorm}). - The normalized energy and execution time curves are not in the same direction. While the main -goal is to optimize the energy and execution time at the same time. According + While the main +goal is to optimize the energy and execution time at the same time, the normalized energy and execution time curves are not in the same direction. According to the equations~(\ref{eq:enorm}) and~(\ref{eq:pnorm}), the set of frequency scaling factors $S_1,S_2,\dots,S_N$ reduce both the energy and the execution time simultaneously. But the main objective is to produce maximum energy -reduction with minimum execution time reduction. Many researchers used +reduction with minimum execution time reduction. + +Many researchers used different strategies to solve this nonlinear problem for example -see~\cite{19,42}, their methods add big overheads to the algorithm to select the -suitable frequency. In this paper we are present a method to find the optimal -set of frequency scaling factors to optimize both energy and execution time -simultaneously without adding a big overhead. Our solution for this problem is +in~\cite{19,42}, their methods add big overheads to the algorithm to select the +suitable frequency. In this paper we present a method to find the optimal +set of frequency scaling factors to simultaneously optimize both energy and execution time + without adding a big overhead. \textbf{put the last two phrases in the related work section} + + + Our solution for this problem is to make the optimization process for energy and execution time follow the same -direction. Therefore, we inverse the equation of the normalized execution time, -the normalized performance, as follows: +direction. Therefore, we inverse the equation of the normalized execution time which gives +the normalized performance equation, as follows: \begin{multline} \label{eq:pnorm_inv} P_\textit{Norm} = \frac{T_\textit{Old}}{T_\textit{New}}\\ @@ -315,9 +320,8 @@ function has the following form: \end{equation} where $N$ is the number of nodes and $F$ is the number of available frequencies for each nodes. Then we can select the optimal set of scaling factors that satisfies EQ~(\ref{eq:max}). Our objective function can -work with any energy model or energy values stored in a data file. -Moreover, this function works in optimal way when the energy curve has a convex -form over the available frequency scaling factors as shown in~\cite{15,3,19}. +work with any energy model or any power values for each node (static and dynamic powers). +However, the most energy reduction gain can be achieved the energy curve has a convex form as shown in~\cite{15,3,19}. \section{The heterogeneous scaling algorithm } \label{sec.optim}