X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/72d32c4e88a57f4786f62fec48a1bfa454adbff9..ce354758f86f0fad1ea536f1cbc0a337267b9987:/src/plugins/host_energy.cpp

diff --git a/src/plugins/host_energy.cpp b/src/plugins/host_energy.cpp
index 6d9483d501..2bf95b1065 100644
--- a/src/plugins/host_energy.cpp
+++ b/src/plugins/host_energy.cpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2010-2022. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2010-2023. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -12,6 +12,7 @@
 #include <simgrid/simix.hpp>
 
 #include "src/kernel/resource/CpuImpl.hpp"
+#include "src/simgrid/module.hpp"
 
 #include <boost/algorithm/string/classification.hpp>
 #include <boost/algorithm/string/split.hpp>
@@ -59,14 +60,25 @@ This is enough to compute the wattage as a function of the amount of loaded core
 
    <table border="1">
    <tr><th>#Cores loaded</th><th>Wattage</th><th>Explanation</th></tr>
-   <tr><td>0 (idle)</td><td> 100 Watts&nbsp;</td><td> Idle value</td></tr>
-   <tr><td>0 (not idle)</td><td> 120 Watts</td><td> Epsilon value</td></tr>
+   <tr><td>0 (idle)</td><td> 100 Watts&nbsp;</td><td>Idle value</td></tr>
    <tr><td>1</td><td> 140 Watts</td><td> Linear extrapolation between Epsilon and AllCores</td></tr>
    <tr><td>2</td><td> 160 Watts</td><td> Linear extrapolation between Epsilon and AllCores</td></tr>
    <tr><td>3</td><td> 180 Watts</td><td> Linear extrapolation between Epsilon and AllCores</td></tr>
    <tr><td>4</td><td> 200 Watts</td><td> AllCores value</td></tr>
    </table>
 
+Here is how it looks graphically:
+
+.. image:: img/plugin-energy.svg
+   :scale: 80%
+   :align: center
+
+As you can see, the ``Epsilon`` parameter allows to freely specify the slope you want, while using the 2 parameters
+version of the model (with only ``Idle`` and ``AllCores``) requires that the ``Idle`` value is on the extension of the
+line crossing the consumption you mesure for each core amount. Please note that specifying the consumption for each core
+amount separately was not a solution because parallel tasks can use an amount of cores that is not an integer. The good
+news is that it was not necessary, as our experiments (detailed in the paper) show that the proposed linear model is
+sufficient to capture reality.
 
 .. raw:: html
 
@@ -94,8 +106,8 @@ This encodes the following values:
    </table>
 
 To change the pstate of a given CPU, use the following functions:
-:cpp:func:`MSG_host_get_nb_pstates()`, :cpp:func:`simgrid::s4u::Host::set_pstate()`,
-:cpp:func:`MSG_host_get_power_peak_at()`.
+:cpp:func:`sg_host_get_nb_pstates()`, :cpp:func:`simgrid::s4u::Host::set_pstate()`,
+:cpp:func:`sg_host_get_pstate_speed()`.
 
 .. raw:: html
 
@@ -216,10 +228,10 @@ HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host_(ptr)
   const char* off_power_str = host_->get_property("wattage_off");
   if (off_power_str != nullptr) {
     try {
-      this->watts_off_ = std::stod(std::string(off_power_str));
+      this->watts_off_ = std::stod(off_power_str);
     } catch (const std::invalid_argument&) {
-      throw std::invalid_argument(std::string("Invalid value for property wattage_off of host ") + host_->get_cname() +
-                                  ": " + off_power_str);
+      throw std::invalid_argument("Invalid value for property wattage_off of host " + host_->get_name() + ": " +
+                                  off_power_str);
     }
   }
   /* watts_off is 0 by default */