X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/e709643ef0c5b61c6c878016c418bffa2b1b20cd..5c5f0f91b9ca71ee758867269b8fe0a04506d559:/src/kernel/lmm/maxmin.cpp

diff --git a/src/kernel/lmm/maxmin.cpp b/src/kernel/lmm/maxmin.cpp
index 3dd1bb67f2..750b662f9d 100644
--- a/src/kernel/lmm/maxmin.cpp
+++ b/src/kernel/lmm/maxmin.cpp
@@ -1,386 +1,17 @@
-/* Copyright (c) 2004-2020. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2004-2023. 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. */
 
 #include "src/kernel/lmm/maxmin.hpp"
-#include "xbt/backtrace.hpp"
+#include "src/simgrid/math_utils.h"
+#include "xbt/ex.h"
 
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_maxmin, surf, "Logging specific to SURF (maxmin)");
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(ker_lmm);
 
-double sg_maxmin_precision = 1E-5; /* Change this with --cfg=maxmin/precision:VALUE */
-double sg_surf_precision   = 1E-9; /* Change this with --cfg=surf/precision:VALUE */
-int sg_concurrency_limit   = -1;      /* Change this with --cfg=maxmin/concurrency-limit:VALUE */
+namespace simgrid::kernel::lmm {
 
-namespace simgrid {
-namespace kernel {
-namespace lmm {
-
-typedef std::vector<int> dyn_light_t;
-
-int Variable::next_rank_   = 1;
-int Constraint::next_rank_ = 1;
-
-System* make_new_maxmin_system(bool selective_update)
-{
-  return new System(selective_update);
-}
-
-int Element::get_concurrency() const
-{
-  // Ignore element with weight less than one (e.g. cross-traffic)
-  return (consumption_weight >= 1) ? 1 : 0;
-  // There are other alternatives, but they will change the behavior of the model..
-  // So do not use it unless you want to make a new model.
-  // If you do, remember to change the variables concurrency share to reflect it.
-  // Potential examples are:
-  // return (elem->weight>0)?1:0;//Include element as soon  as weight is non-zero
-  // return (int)ceil(elem->weight);//Include element as the rounded-up integer value of the element weight
-}
-
-void Element::decrease_concurrency()
-{
-  xbt_assert(constraint->concurrency_current_ >= get_concurrency());
-  constraint->concurrency_current_ -= get_concurrency();
-}
-
-void Element::increase_concurrency()
-{
-  constraint->concurrency_current_ += get_concurrency();
-
-  if (constraint->concurrency_current_ > constraint->concurrency_maximum_)
-    constraint->concurrency_maximum_ = constraint->concurrency_current_;
-
-  xbt_assert(constraint->get_concurrency_limit() < 0 ||
-                 constraint->concurrency_current_ <= constraint->get_concurrency_limit(),
-             "Concurrency limit overflow!");
-}
-
-void System::check_concurrency() const
-{
-  // These checks are very expensive, so do them only if we want to debug SURF LMM
-  if (not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug))
-    return;
-
-  for (Constraint const& cnst : constraint_set) {
-    int concurrency       = 0;
-    for (Element const& elem : cnst.enabled_element_set_) {
-      xbt_assert(elem.variable->sharing_penalty_ > 0);
-      concurrency += elem.get_concurrency();
-    }
-
-    for (Element const& elem : cnst.disabled_element_set_) {
-      // We should have staged variables only if concurrency is reached in some constraint
-      xbt_assert(cnst.get_concurrency_limit() < 0 || elem.variable->staged_penalty_ == 0 ||
-                     elem.variable->get_min_concurrency_slack() < elem.variable->concurrency_share_,
-                 "should not have staged variable!");
-    }
-
-    xbt_assert(cnst.get_concurrency_limit() < 0 || cnst.get_concurrency_limit() >= concurrency,
-               "concurrency check failed!");
-    xbt_assert(cnst.concurrency_current_ == concurrency, "concurrency_current is out-of-date!");
-  }
-
-  // Check that for each variable, all corresponding elements are in the same state (i.e. same element sets)
-  for (Variable const& var : variable_set) {
-    if (var.cnsts_.empty())
-      continue;
-
-    const Element& elem    = var.cnsts_[0];
-    bool belong_to_enabled  = elem.enabled_element_set_hook.is_linked();
-    bool belong_to_disabled = elem.disabled_element_set_hook.is_linked();
-    bool belong_to_active   = elem.active_element_set_hook.is_linked();
-
-    for (Element const& elem2 : var.cnsts_) {
-      xbt_assert(belong_to_enabled == elem2.enabled_element_set_hook.is_linked(),
-                 "Variable inconsistency (1): enabled_element_set");
-      xbt_assert(belong_to_disabled == elem2.disabled_element_set_hook.is_linked(),
-                 "Variable inconsistency (2): disabled_element_set");
-      xbt_assert(belong_to_active == elem2.active_element_set_hook.is_linked(),
-                 "Variable inconsistency (3): active_element_set");
-    }
-  }
-}
-
-void System::var_free(Variable* var)
-{
-  XBT_IN("(sys=%p, var=%p)", this, var);
-  modified_ = true;
-
-  // TODOLATER Can do better than that by leaving only the variable in only one enabled_element_set, call
-  // update_modified_set, and then remove it..
-  if (not var->cnsts_.empty())
-    update_modified_set(var->cnsts_[0].constraint);
-
-  for (Element& elem : var->cnsts_) {
-    if (var->sharing_penalty_ > 0)
-      elem.decrease_concurrency();
-    if (elem.enabled_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->enabled_element_set_, elem);
-    if (elem.disabled_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->disabled_element_set_, elem);
-    if (elem.active_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->active_element_set_, elem);
-    int nelements = elem.constraint->enabled_element_set_.size() + elem.constraint->disabled_element_set_.size();
-    if (nelements == 0)
-      make_constraint_inactive(elem.constraint);
-    else
-      on_disabled_var(elem.constraint);
-  }
-
-  var->cnsts_.clear();
-
-  check_concurrency();
-
-  xbt_mallocator_release(variable_mallocator_, var);
-  XBT_OUT();
-}
-
-System::System(bool selective_update) : selective_update_active(selective_update)
-{
-  XBT_DEBUG("Setting selective_update_active flag to %d", selective_update_active);
-
-  if (selective_update)
-    modified_set_ = new kernel::resource::Action::ModifiedSet();
-}
-
-System::~System()
-{
-  Variable* var;
-  Constraint* cnst;
-
-  while ((var = extract_variable())) {
-    auto demangled = simgrid::xbt::demangle(var->id_ ? typeid(*var->id_).name() : "(unidentified)");
-    XBT_WARN("Probable bug: a %s variable (#%d) not removed before the LMM system destruction.", demangled.get(),
-             var->rank_);
-    var_free(var);
-  }
-  while ((cnst = extract_constraint()))
-    cnst_free(cnst);
-
-  xbt_mallocator_free(variable_mallocator_);
-  delete modified_set_;
-}
-
-void System::cnst_free(Constraint* cnst)
-{
-  make_constraint_inactive(cnst);
-  delete cnst;
-}
-
-Constraint::Constraint(resource::Resource* id_value, double bound_value) : bound_(bound_value), id_(id_value)
-{
-  rank_ = next_rank_++;
-}
-
-Constraint* System::constraint_new(resource::Resource* id, double bound_value)
-{
-  Constraint* cnst = new Constraint(id, bound_value);
-  insert_constraint(cnst);
-  return cnst;
-}
-
-void* System::variable_mallocator_new_f()
-{
-  return new Variable;
-}
-
-void System::variable_mallocator_free_f(void* var)
-{
-  delete static_cast<Variable*>(var);
-}
-
-Variable* System::variable_new(resource::Action* id, double sharing_penalty, double bound, size_t number_of_constraints)
-{
-  XBT_IN("(sys=%p, id=%p, penalty=%f, bound=%f, num_cons =%zu)", this, id, sharing_penalty, bound,
-         number_of_constraints);
-
-  Variable* var = static_cast<Variable*>(xbt_mallocator_get(variable_mallocator_));
-  var->initialize(id, sharing_penalty, bound, number_of_constraints, visited_counter_ - 1);
-  if (sharing_penalty > 0)
-    variable_set.push_front(*var);
-  else
-    variable_set.push_back(*var);
-
-  XBT_OUT(" returns %p", var);
-  return var;
-}
-
-void System::variable_free(Variable* var)
-{
-  remove_variable(var);
-  var_free(var);
-}
-
-void System::variable_free_all()
-{
-  Variable* var;
-  while ((var = extract_variable()))
-    variable_free(var);
-}
-
-void System::expand(Constraint* cnst, Variable* var, double consumption_weight)
-{
-  modified_ = true;
-
-  // Check if this variable already has an active element in this constraint
-  // If it does, subtract it from the required slack
-  int current_share = 0;
-  if (var->concurrency_share_ > 1) {
-    for (const Element& elem : var->cnsts_) {
-      if (elem.constraint == cnst && elem.enabled_element_set_hook.is_linked())
-        current_share += elem.get_concurrency();
-    }
-  }
-
-  // Check if we need to disable the variable
-  if (var->sharing_penalty_ > 0 && var->concurrency_share_ - current_share > cnst->get_concurrency_slack()) {
-    double penalty = var->sharing_penalty_;
-    disable_var(var);
-    for (Element const& elem : var->cnsts_)
-      on_disabled_var(elem.constraint);
-    consumption_weight = 0;
-    var->staged_penalty_ = penalty;
-    xbt_assert(not var->sharing_penalty_);
-  }
-
-  xbt_assert(var->cnsts_.size() < var->cnsts_.capacity(), "Too much constraints");
-
-  var->cnsts_.resize(var->cnsts_.size() + 1);
-  Element& elem = var->cnsts_.back();
-
-  elem.consumption_weight = consumption_weight;
-  elem.constraint         = cnst;
-  elem.variable           = var;
-
-  if (var->sharing_penalty_ != 0.0) {
-    elem.constraint->enabled_element_set_.push_front(elem);
-    elem.increase_concurrency();
-  } else
-    elem.constraint->disabled_element_set_.push_back(elem);
-
-  if (not selective_update_active) {
-    make_constraint_active(cnst);
-  } else if (elem.consumption_weight > 0 || var->sharing_penalty_ > 0) {
-    make_constraint_active(cnst);
-    update_modified_set(cnst);
-    // TODOLATER: Why do we need this second call?
-    if (var->cnsts_.size() > 1)
-      update_modified_set(var->cnsts_[0].constraint);
-  }
-
-  check_concurrency();
-}
-
-void System::expand_add(Constraint* cnst, Variable* var, double value)
-{
-  modified_ = true;
-
-  check_concurrency();
-
-  // BEWARE: In case you have multiple elements in one constraint, this will always add value to the first element.
-  auto elem_it =
-      std::find_if(begin(var->cnsts_), end(var->cnsts_), [&cnst](Element const& x) { return x.constraint == cnst; });
-  if (elem_it != end(var->cnsts_)) {
-    Element& elem = *elem_it;
-    if (var->sharing_penalty_ != 0.0)
-      elem.decrease_concurrency();
-
-    if (cnst->sharing_policy_ != s4u::Link::SharingPolicy::FATPIPE)
-      elem.consumption_weight += value;
-    else
-      elem.consumption_weight = std::max(elem.consumption_weight, value);
-
-    // We need to check that increasing value of the element does not cross the concurrency limit
-    if (var->sharing_penalty_ != 0.0) {
-      if (cnst->get_concurrency_slack() < elem.get_concurrency()) {
-        double penalty = var->sharing_penalty_;
-        disable_var(var);
-        for (Element const& elem2 : var->cnsts_)
-          on_disabled_var(elem2.constraint);
-        var->staged_penalty_ = penalty;
-        xbt_assert(not var->sharing_penalty_);
-      }
-      elem.increase_concurrency();
-    }
-    update_modified_set(cnst);
-  } else
-    expand(cnst, var, value);
-
-  check_concurrency();
-}
-
-Variable* Constraint::get_variable(const Element** elem) const
-{
-  if (*elem == nullptr) {
-    // That is the first call, pick the first element among enabled_element_set (or disabled_element_set if
-    // enabled_element_set is empty)
-    if (not enabled_element_set_.empty())
-      *elem = &enabled_element_set_.front();
-    else if (not disabled_element_set_.empty())
-      *elem = &disabled_element_set_.front();
-    else
-      *elem = nullptr;
-  } else {
-    // elem is not null, so we carry on
-    if ((*elem)->enabled_element_set_hook.is_linked()) {
-      // Look at enabled_element_set, and jump to disabled_element_set when finished
-      auto iter = std::next(enabled_element_set_.iterator_to(**elem));
-      if (iter != std::end(enabled_element_set_))
-        *elem = &*iter;
-      else if (not disabled_element_set_.empty())
-        *elem = &disabled_element_set_.front();
-      else
-        *elem = nullptr;
-    } else {
-      auto iter = std::next(disabled_element_set_.iterator_to(**elem));
-      *elem     = iter != std::end(disabled_element_set_) ? &*iter : nullptr;
-    }
-  }
-  if (*elem)
-    return (*elem)->variable;
-  else
-    return nullptr;
-}
-
-// if we modify the list between calls, normal version may loop forever
-// this safe version ensures that we browse the list elements only once
-Variable* Constraint::get_variable_safe(const Element** elem, const Element** nextelem, int* numelem) const
-{
-  if (*elem == nullptr) {
-    *numelem = enabled_element_set_.size() + disabled_element_set_.size() - 1;
-    if (not enabled_element_set_.empty())
-      *elem = &enabled_element_set_.front();
-    else if (not disabled_element_set_.empty())
-      *elem = &disabled_element_set_.front();
-    else
-      *elem = nullptr;
-  } else {
-    *elem = *nextelem;
-    if (*numelem > 0) {
-      (*numelem)--;
-    } else
-      return nullptr;
-  }
-  if (*elem) {
-    // elem is not null, so we carry on
-    if ((*elem)->enabled_element_set_hook.is_linked()) {
-      // Look at enabled_element_set, and jump to disabled_element_set when finished
-      auto iter = std::next(enabled_element_set_.iterator_to(**elem));
-      if (iter != std::end(enabled_element_set_))
-        *nextelem = &*iter;
-      else if (not disabled_element_set_.empty())
-        *nextelem = &disabled_element_set_.front();
-      else
-        *nextelem = nullptr;
-    } else {
-      auto iter = std::next(disabled_element_set_.iterator_to(**elem));
-      *nextelem = iter != std::end(disabled_element_set_) ? &*iter : nullptr;
-    }
-    return (*elem)->variable;
-  } else
-    return nullptr;
-}
+using dyn_light_t = std::vector<int>;
 
 static inline void saturated_constraints_update(double usage, int cnst_light_num, dyn_light_t& saturated_constraints,
                                                 double* min_usage)
@@ -411,83 +42,20 @@ static inline void saturated_variable_set_update(const ConstraintLight* cnst_lig
   }
 }
 
-template <class ElemList>
-static void format_element_list(const ElemList& elem_list, s4u::Link::SharingPolicy sharing_policy, double& sum,
-                                std::string& buf)
-{
-  for (Element const& elem : elem_list) {
-    buf += std::to_string(elem.consumption_weight) + ".'" + std::to_string(elem.variable->rank_) + "'(" +
-           std::to_string(elem.variable->value_) + ")" +
-           (sharing_policy != s4u::Link::SharingPolicy::FATPIPE ? " + " : " , ");
-    if (sharing_policy != s4u::Link::SharingPolicy::FATPIPE)
-      sum += elem.consumption_weight * elem.variable->value_;
-    else
-      sum = std::max(sum, elem.consumption_weight * elem.variable->value_);
-  }
-}
-
-void System::print() const
+void MaxMin::do_solve()
 {
-  std::string buf = std::string("MAX-MIN ( ");
-
-  /* Printing Objective */
-  for (Variable const& var : variable_set)
-    buf += "'" + std::to_string(var.rank_) + "'(" + std::to_string(var.sharing_penalty_) + ") ";
-  buf += ")";
-  XBT_DEBUG("%20s", buf.c_str());
-  buf.clear();
-
-  XBT_DEBUG("Constraints");
-  /* Printing Constraints */
-  for (Constraint const& cnst : active_constraint_set) {
-    double sum            = 0.0;
-    // Show  the enabled variables
-    buf += "\t";
-    buf += cnst.sharing_policy_ != s4u::Link::SharingPolicy::FATPIPE ? "(" : "max(";
-    format_element_list(cnst.enabled_element_set_, cnst.sharing_policy_, sum, buf);
-    // TODO: Adding disabled elements only for test compatibility, but do we really want them to be printed?
-    format_element_list(cnst.disabled_element_set_, cnst.sharing_policy_, sum, buf);
-
-    buf += "0) <= " + std::to_string(cnst.bound_) + " ('" + std::to_string(cnst.rank_) + "')";
-
-    if (cnst.sharing_policy_ == s4u::Link::SharingPolicy::FATPIPE) {
-      buf += " [MAX-Constraint]";
-    }
-    XBT_DEBUG("%s", buf.c_str());
-    buf.clear();
-    xbt_assert(not double_positive(sum - cnst.bound_, cnst.bound_ * sg_maxmin_precision),
-               "Incorrect value (%f is not smaller than %f): %g", sum, cnst.bound_, sum - cnst.bound_);
-  }
-
-  XBT_DEBUG("Variables");
-  /* Printing Result */
-  for (Variable const& var : variable_set) {
-    if (var.bound_ > 0) {
-      XBT_DEBUG("'%d'(%f) : %f (<=%f)", var.rank_, var.sharing_penalty_, var.value_, var.bound_);
-      xbt_assert(not double_positive(var.value_ - var.bound_, var.bound_ * sg_maxmin_precision),
-                 "Incorrect value (%f is not smaller than %f", var.value_, var.bound_);
-    } else {
-      XBT_DEBUG("'%d'(%f) : %f", var.rank_, var.sharing_penalty_, var.value_);
-    }
-  }
-}
-
-void System::lmm_solve()
-{
-  if (modified_) {
-    XBT_IN("(sys=%p)", this);
-    /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only
-     * constraints that changed are considered. Otherwise all constraints with active actions are considered.
-     */
-    if (selective_update_active)
-      lmm_solve(modified_constraint_set);
-    else
-      lmm_solve(active_constraint_set);
-    XBT_OUT();
-  }
+  XBT_IN("(sys=%p)", this);
+  /* Compute Usage and store the variables that reach the maximum. If selective_update_active is true, only
+   * constraints that changed are considered. Otherwise all constraints with active actions are considered.
+   */
+  if (selective_update_active)
+    maxmin_solve(modified_constraint_set);
+  else
+    maxmin_solve(active_constraint_set);
+  XBT_OUT();
 }
 
-template <class CnstList> void System::lmm_solve(CnstList& cnst_list)
+template <class CnstList> void MaxMin::maxmin_solve(CnstList& cnst_list)
 {
   double min_usage = -1;
   double min_bound = -1;
@@ -500,23 +68,24 @@ template <class CnstList> void System::lmm_solve(CnstList& cnst_list)
   for (Constraint& cnst : cnst_list) {
     /* INIT: Collect constraints that actually need to be saturated (i.e remaining  and usage are strictly positive)
      * into cnst_light_tab. */
-    cnst.remaining_ = cnst.bound_;
-    if (not double_positive(cnst.remaining_, cnst.bound_ * sg_maxmin_precision))
+    cnst.dynamic_bound_ = cnst.bound_;
+    if ((cnst.get_sharing_policy() == Constraint::SharingPolicy::NONLINEAR || cnst.get_sharing_policy() == Constraint::SharingPolicy::WIFI) && cnst.dyn_constraint_cb_) {
+      cnst.dynamic_bound_ = cnst.dyn_constraint_cb_(cnst.bound_, cnst.concurrency_current_);
+    }
+    cnst.remaining_ = cnst.dynamic_bound_;
+    if (not double_positive(cnst.remaining_, cnst.dynamic_bound_ * sg_precision_workamount))
       continue;
     cnst.usage_ = 0;
     for (Element& elem : cnst.enabled_element_set_) {
       xbt_assert(elem.variable->sharing_penalty_ > 0.0);
       elem.variable->value_ = 0.0;
       if (elem.consumption_weight > 0) {
-        if (cnst.sharing_policy_ != s4u::Link::SharingPolicy::FATPIPE)
+        if (cnst.sharing_policy_ != Constraint::SharingPolicy::FATPIPE)
           cnst.usage_ += elem.consumption_weight / elem.variable->sharing_penalty_;
         else if (cnst.usage_ < elem.consumption_weight / elem.variable->sharing_penalty_)
           cnst.usage_ = elem.consumption_weight / elem.variable->sharing_penalty_;
 
         elem.make_active();
-        resource::Action* action = elem.variable->id_;
-        if (modified_set_ && not action->is_within_modified_set())
-          modified_set_->push_back(*action);
       }
     }
     XBT_DEBUG("Constraint '%d' usage: %f remaining: %f concurrency: %i<=%i<=%i", cnst.rank_, cnst.usage_,
@@ -565,34 +134,35 @@ template <class CnstList> void System::lmm_solve(CnstList& cnst_list)
         XBT_DEBUG("Setting var (%d) value to %f\n", var.rank_, var.value_);
       } else {
         // If there exist a variable that can reach its bound, only update it (and other with the same bound) for now.
-        if (double_equals(min_bound, var.bound_ * var.sharing_penalty_, sg_maxmin_precision)) {
+        if (double_equals(min_bound, var.bound_ * var.sharing_penalty_, sg_precision_workamount)) {
           var.value_ = var.bound_;
           XBT_DEBUG("Setting %p (%d) value to %f\n", &var, var.rank_, var.value_);
         } else {
           // Variables which bound is different are not considered for this cycle, but they will be afterwards.
-          XBT_DEBUG("Do not consider %p (%d) \n", &var, var.rank_);
+          XBT_DEBUG("Do not consider %p (%d)\n", &var, var.rank_);
           var_list.pop_front();
           continue;
         }
       }
-      XBT_DEBUG("Min usage: %f, Var(%d).penalty: %f, Var(%d).value: %f ", min_usage, var.rank_, var.sharing_penalty_,
+      XBT_DEBUG("Min usage: %f, Var(%d).penalty: %f, Var(%d).value: %f", min_usage, var.rank_, var.sharing_penalty_,
                 var.rank_, var.value_);
 
       /* Update the usage of constraints where this variable is involved */
       for (Element& elem : var.cnsts_) {
         Constraint* cnst = elem.constraint;
-        if (cnst->sharing_policy_ != s4u::Link::SharingPolicy::FATPIPE) {
+        if (cnst->sharing_policy_ != Constraint::SharingPolicy::FATPIPE) {
           // Remember: shared constraints require that sum(elem.value * var.value) < cnst->bound
-          double_update(&(cnst->remaining_), elem.consumption_weight * var.value_, cnst->bound_ * sg_maxmin_precision);
-          double_update(&(cnst->usage_), elem.consumption_weight / var.sharing_penalty_, sg_maxmin_precision);
+          double_update(&(cnst->remaining_), elem.consumption_weight * var.value_,
+                        cnst->dynamic_bound_ * sg_precision_workamount);
+          double_update(&(cnst->usage_), elem.consumption_weight / var.sharing_penalty_, sg_precision_workamount);
           // If the constraint is saturated, remove it from the set of active constraints (light_tab)
-          if (not double_positive(cnst->usage_, sg_maxmin_precision) ||
-              not double_positive(cnst->remaining_, cnst->bound_ * sg_maxmin_precision)) {
+          if (not double_positive(cnst->usage_, sg_precision_workamount) ||
+              not double_positive(cnst->remaining_, cnst->dynamic_bound_ * sg_precision_workamount)) {
             if (cnst->cnst_light_) {
-              int index = (cnst->cnst_light_ - cnst_light_tab);
-              XBT_DEBUG("index: %d \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f  ", index,
-                        cnst_light_num, cnst->usage_, cnst->remaining_, cnst->bound_);
-              cnst_light_tab[index]                  = cnst_light_tab[cnst_light_num - 1];
+              size_t index = (cnst->cnst_light_ - cnst_light_tab);
+              XBT_DEBUG("index: %zu \t cnst_light_num: %d \t || usage: %f remaining: %f bound: %f", index,
+                        cnst_light_num, cnst->usage_, cnst->remaining_, cnst->dynamic_bound_);
+              cnst_light_tab[index]                   = cnst_light_tab[cnst_light_num - 1];
               cnst_light_tab[index].cnst->cnst_light_ = &cnst_light_tab[index];
               cnst_light_num--;
               cnst->cnst_light_ = nullptr;
@@ -615,15 +185,15 @@ template <class CnstList> void System::lmm_solve(CnstList& cnst_list)
               cnst->usage_ = std::max(cnst->usage_, elem2.consumption_weight / elem2.variable->sharing_penalty_);
           }
           // If the constraint is saturated, remove it from the set of active constraints (light_tab)
-          if (not double_positive(cnst->usage_, sg_maxmin_precision) ||
-              not double_positive(cnst->remaining_, cnst->bound_ * sg_maxmin_precision)) {
+          if (not double_positive(cnst->usage_, sg_precision_workamount) ||
+              not double_positive(cnst->remaining_, cnst->dynamic_bound_ * sg_precision_workamount)) {
             if (cnst->cnst_light_) {
-              int index = (cnst->cnst_light_ - cnst_light_tab);
-              XBT_DEBUG("index: %d \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
-                        "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f  ",
+              size_t index = (cnst->cnst_light_ - cnst_light_tab);
+              XBT_DEBUG("index: %zu \t cnst_light_num: %d \t || \t cnst: %p \t cnst->cnst_light: %p "
+                        "\t cnst_light_tab: %p usage: %f remaining: %f bound: %f",
                         index, cnst_light_num, cnst, cnst->cnst_light_, cnst_light_tab, cnst->usage_, cnst->remaining_,
-                        cnst->bound_);
-              cnst_light_tab[index]                  = cnst_light_tab[cnst_light_num - 1];
+                        cnst->dynamic_bound_);
+              cnst_light_tab[index]                   = cnst_light_tab[cnst_light_num - 1];
               cnst_light_tab[index].cnst->cnst_light_ = &cnst_light_tab[index];
               cnst_light_num--;
               cnst->cnst_light_ = nullptr;
@@ -645,304 +215,19 @@ template <class CnstList> void System::lmm_solve(CnstList& cnst_list)
     min_usage = -1;
     min_bound = -1;
     saturated_constraints.clear();
-    int pos;
-    for (pos = 0; pos < cnst_light_num; pos++) {
-      xbt_assert(not cnst_light_tab[pos].cnst->active_element_set_.empty(),
-                 "Cannot saturate more a constraint that has"
-                 " no active element! You may want to change the maxmin precision (--cfg=maxmin/precision:<new_value>)"
-                 " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
-                 "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
-                 cnst_light_tab[pos].cnst->usage_, sg_maxmin_precision, cnst_light_tab[pos - 1].cnst->usage_);
+    for (int pos = 0; pos < cnst_light_num; pos++) {
+      xbt_assert(
+          not cnst_light_tab[pos].cnst->active_element_set_.empty(),
+          "Cannot saturate more a constraint that has"
+          " no active element! You may want to change the work amount precision (--cfg=maxmin/precision:<new_value>)"
+          " because of possible rounding effects.\n\tFor the record, the usage of this constraint is %g while "
+          "the maxmin precision to which it is compared is %g.\n\tThe usage of the previous constraint is %g.",
+          cnst_light_tab[pos].cnst->usage_, sg_precision_workamount, cnst_light_tab[pos - 1].cnst->usage_);
       saturated_constraints_update(cnst_light_tab[pos].remaining_over_usage, pos, saturated_constraints, &min_usage);
     }
 
     saturated_variable_set_update(cnst_light_tab, saturated_constraints, this);
   } while (cnst_light_num > 0);
-
-  modified_ = false;
-  if (selective_update_active)
-    remove_all_modified_set();
-
-  if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
-    print();
-  }
-
-  check_concurrency();
-}
-
-/** @brief Attribute the value bound to var->bound.
- *
- *  @param var the Variable*
- *  @param bound the new bound to associate with var
- *
- *  Makes var->bound equal to bound. Whenever this function is called a change is  signed in the system. To
- *  avoid false system changing detection it is a good idea to test (bound != 0) before calling it.
- */
-void System::update_variable_bound(Variable* var, double bound)
-{
-  modified_  = true;
-  var->bound_ = bound;
-
-  if (not var->cnsts_.empty())
-    update_modified_set(var->cnsts_[0].constraint);
-}
-
-void Variable::initialize(resource::Action* id_value, double sharing_penalty, double bound_value,
-                          int number_of_constraints, unsigned visited_value)
-{
-  id_     = id_value;
-  rank_   = next_rank_++;
-  cnsts_.reserve(number_of_constraints);
-  sharing_penalty_   = sharing_penalty;
-  staged_penalty_    = 0.0;
-  bound_             = bound_value;
-  concurrency_share_ = 1;
-  value_             = 0.0;
-  visited_           = visited_value;
-  mu_                = 0.0;
-
-  xbt_assert(not variable_set_hook_.is_linked());
-  xbt_assert(not saturated_variable_set_hook_.is_linked());
-}
-
-int Variable::get_min_concurrency_slack() const
-{
-  int minslack = std::numeric_limits<int>::max();
-  for (Element const& elem : cnsts_) {
-    int slack = elem.constraint->get_concurrency_slack();
-    if (slack < minslack) {
-      // This is only an optimization, to avoid looking at more constraints when slack is already zero
-      if (slack == 0)
-        return 0;
-      minslack = slack;
-    }
-  }
-  return minslack;
-}
-
-// Small remark: In this implementation of System::enable_var() and System::disable_var(), we will meet multiple times
-// with var when running System::update_modified_set().
-// A priori not a big performance issue, but we might do better by calling System::update_modified_set() within the for
-// loops (after doing the first for enabling==1, and before doing the last for disabling==1)
-void System::enable_var(Variable* var)
-{
-  xbt_assert(not XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug) || var->can_enable());
-
-  var->sharing_penalty_ = var->staged_penalty_;
-  var->staged_penalty_  = 0;
-
-  // Enabling the variable, move var to list head. Subtlety is: here, we need to call update_modified_set AFTER
-  // moving at least one element of var.
-
-  simgrid::xbt::intrusive_erase(variable_set, *var);
-  variable_set.push_front(*var);
-  for (Element& elem : var->cnsts_) {
-    simgrid::xbt::intrusive_erase(elem.constraint->disabled_element_set_, elem);
-    elem.constraint->enabled_element_set_.push_front(elem);
-    elem.increase_concurrency();
-  }
-  if (not var->cnsts_.empty())
-    update_modified_set(var->cnsts_[0].constraint);
-
-  // When used within on_disabled_var, we would get an assertion fail, because transiently there can be variables
-  // that are staged and could be activated.
-  // Anyway, caller functions all call check_concurrency() in the end.
-}
-
-void System::disable_var(Variable* var)
-{
-  xbt_assert(not var->staged_penalty_, "Staged penalty should have been cleared");
-  // Disabling the variable, move to var to list tail. Subtlety is: here, we need to call update_modified_set
-  // BEFORE moving the last element of var.
-  simgrid::xbt::intrusive_erase(variable_set, *var);
-  variable_set.push_back(*var);
-  if (not var->cnsts_.empty())
-    update_modified_set(var->cnsts_[0].constraint);
-  for (Element& elem : var->cnsts_) {
-    simgrid::xbt::intrusive_erase(elem.constraint->enabled_element_set_, elem);
-    elem.constraint->disabled_element_set_.push_back(elem);
-    if (elem.active_element_set_hook.is_linked())
-      simgrid::xbt::intrusive_erase(elem.constraint->active_element_set_, elem);
-    elem.decrease_concurrency();
-  }
-
-  var->sharing_penalty_ = 0.0;
-  var->staged_penalty_  = 0.0;
-  var->value_          = 0.0;
-  check_concurrency();
-}
-
-/* /brief Find variables that can be enabled and enable them.
- *
- * Assuming that the variable has already been removed from non-zero penalties
- * Can we find a staged variable to add?
- * If yes, check that none of the constraints that this variable is involved in is at the limit of its concurrency
- * And then add it to enabled variables
- */
-void System::on_disabled_var(Constraint* cnstr)
-{
-  if (cnstr->get_concurrency_limit() < 0)
-    return;
-
-  int numelem = cnstr->disabled_element_set_.size();
-  if (not numelem)
-    return;
-
-  Element* elem = &cnstr->disabled_element_set_.front();
-
-  // Cannot use foreach loop, because System::enable_var() will modify disabled_element_set.. within the loop
-  while (numelem-- && elem) {
-    Element* nextelem;
-    if (elem->disabled_element_set_hook.is_linked()) {
-      auto iter = std::next(cnstr->disabled_element_set_.iterator_to(*elem));
-      nextelem  = iter != std::end(cnstr->disabled_element_set_) ? &*iter : nullptr;
-    } else {
-      nextelem = nullptr;
-    }
-
-    if (elem->variable->staged_penalty_ > 0 && elem->variable->can_enable()) {
-      // Found a staged variable
-      // TODOLATER: Add random timing function to model reservation protocol fuzziness? Then how to make sure that
-      // staged variables will eventually be called?
-      enable_var(elem->variable);
-    }
-
-    xbt_assert(cnstr->concurrency_current_ <= cnstr->get_concurrency_limit(), "Concurrency overflow!");
-    if (cnstr->concurrency_current_ == cnstr->get_concurrency_limit())
-      break;
-
-    elem = nextelem;
-  }
-
-  // We could get an assertion fail, because transiently there can be variables that are staged and could be activated.
-  // And we need to go through all constraints of the disabled var before getting back a coherent state.
-  // Anyway, caller functions all call check_concurrency() in the end.
-}
-
-/** @brief update the penalty of a variable (disable it by passing 0 as a penalty) */
-void System::update_variable_penalty(Variable* var, double penalty)
-{
-  xbt_assert(penalty >= 0, "Variable penalty should not be negative!");
-
-  if (penalty == var->sharing_penalty_)
-    return;
-
-  bool enabling_var  = (penalty > 0 && var->sharing_penalty_ <= 0);
-  bool disabling_var = (penalty <= 0 && var->sharing_penalty_ > 0);
-
-  XBT_IN("(sys=%p, var=%p, penalty=%f)", this, var, penalty);
-
-  modified_ = true;
-
-  // Are we enabling this variable?
-  if (enabling_var) {
-    var->staged_penalty_ = penalty;
-    int minslack       = var->get_min_concurrency_slack();
-    if (minslack < var->concurrency_share_) {
-      XBT_DEBUG("Staging var (instead of enabling) because min concurrency slack %i, with penalty %f and concurrency"
-                " share %i",
-                minslack, penalty, var->concurrency_share_);
-      return;
-    }
-    XBT_DEBUG("Enabling var with min concurrency slack %i", minslack);
-    enable_var(var);
-  } else if (disabling_var) {
-    disable_var(var);
-  } else {
-    var->sharing_penalty_ = penalty;
-  }
-
-  check_concurrency();
-
-  XBT_OUT();
-}
-
-void System::update_constraint_bound(Constraint* cnst, double bound)
-{
-  modified_ = true;
-  update_modified_set(cnst);
-  cnst->bound_ = bound;
-}
-
-/** @brief Update the constraint set propagating recursively to other constraints so the system should not be entirely
- *  computed.
- *
- *  @param cnst the Constraint* affected by the change
- *
- *  A recursive algorithm to optimize the system recalculation selecting only constraints that have changed. Each
- *  constraint change is propagated to the list of constraints for each variable.
- */
-void System::update_modified_set_rec(const Constraint* cnst)
-{
-  for (Element const& elem : cnst->enabled_element_set_) {
-    Variable* var = elem.variable;
-    for (Element const& elem2 : var->cnsts_) {
-      if (var->visited_ == visited_counter_)
-        break;
-      if (elem2.constraint != cnst && not elem2.constraint->modified_constraint_set_hook_.is_linked()) {
-        modified_constraint_set.push_back(*elem2.constraint);
-        update_modified_set_rec(elem2.constraint);
-      }
-    }
-    // var will be ignored in later visits as long as sys->visited_counter does not move
-    var->visited_ = visited_counter_;
-  }
-}
-
-void System::update_modified_set(Constraint* cnst)
-{
-  /* nothing to do if selective update isn't active */
-  if (selective_update_active && not cnst->modified_constraint_set_hook_.is_linked()) {
-    modified_constraint_set.push_back(*cnst);
-    update_modified_set_rec(cnst);
-  }
-}
-
-void System::remove_all_modified_set()
-{
-  // We cleverly un-flag all variables just by incrementing visited_counter
-  // In effect, the var->visited value will no more be equal to visited counter
-  // To be clean, when visited counter has wrapped around, we force these var->visited values so that variables that
-  // were in the modified a long long time ago are not wrongly skipped here, which would lead to very nasty bugs
-  // (i.e. not readily reproducible, and requiring a lot of run time before happening).
-  if (++visited_counter_ == 1) {
-    /* the counter wrapped around, reset each variable->visited */
-    for (Variable& var : variable_set)
-      var.visited_ = 0;
-  }
-  modified_constraint_set.clear();
-}
-
-/**
- * Returns resource load (in flop per second, or byte per second, or similar)
- *
- * If the resource is shared (the default case), the load is sum of resource usage made by
- * every variables located on this resource.
- *
- * If the resource is not shared (ie in FATPIPE mode), then the load is the max (not the sum)
- * of all resource usages located on this resource.
- */
-double Constraint::get_usage() const
-{
-  double result              = 0.0;
-  if (sharing_policy_ != s4u::Link::SharingPolicy::FATPIPE) {
-    for (Element const& elem : enabled_element_set_)
-      if (elem.consumption_weight > 0)
-        result += elem.consumption_weight * elem.variable->value_;
-  } else {
-    for (Element const& elem : enabled_element_set_)
-      if (elem.consumption_weight > 0)
-        result = std::max(result, elem.consumption_weight * elem.variable->value_);
-  }
-  return result;
-}
-
-int Constraint::get_variable_amount() const
-{
-  return static_cast<int>(std::count_if(std::begin(enabled_element_set_), std::end(enabled_element_set_),
-                                        [](const Element& elem) { return elem.consumption_weight > 0; }));
 }
 
-} // namespace lmm
-} // namespace kernel
-} // namespace simgrid
+} // namespace simgrid::kernel::lmm