X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/3bc540848ce00852f978543788dadbd1e6367b60..b4595a628d4c56a820ee58dc6b4f967802abceee:/src/surf/maxmin.c

diff --git a/src/surf/maxmin.c b/src/surf/maxmin.c
index eb3ad2f399..e68add0f08 100644
--- a/src/surf/maxmin.c
+++ b/src/surf/maxmin.c
@@ -1,6 +1,5 @@
-/* 	$Id$	 */
-
-/* Copyright (c) 2004 Arnaud Legrand. All rights reserved.                  */
+/* Copyright (c) 2004-2011. 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. */
@@ -16,15 +15,18 @@
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_maxmin, surf,
                                 "Logging specific to SURF (maxmin)");
 
+double sg_maxmin_precision = 0.00001;
+
 static void *lmm_variable_mallocator_new_f(void);
 static void lmm_variable_mallocator_free_f(void *var);
-static void lmm_variable_mallocator_reset_f(void *var);
-static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst);
+#define lmm_variable_mallocator_reset_f ((void_f_pvoid_t)NULL)
+static void lmm_update_modified_set(lmm_system_t sys,
+                                    lmm_constraint_t cnst);
 static void lmm_remove_all_modified_set(lmm_system_t sys);
-int sg_maxmin_selective_update = 1;
 static int Global_debug_id = 1;
 static int Global_const_debug_id = 1;
-lmm_system_t lmm_system_new(void)
+
+lmm_system_t lmm_system_new(int selective_update)
 {
   lmm_system_t l = NULL;
   s_lmm_variable_t var;
@@ -33,9 +35,10 @@ lmm_system_t lmm_system_new(void)
   l = xbt_new0(s_lmm_system_t, 1);
 
   l->modified = 0;
-  l->selective_update_active = sg_maxmin_selective_update;
+  l->selective_update_active = selective_update;
+  l->visited_counter = 1;
 
-  DEBUG1("Setting selective_update_active flag to %d\n",
+  XBT_DEBUG("Setting selective_update_active flag to %d\n",
          l->selective_update_active);
 
   xbt_swag_init(&(l->variable_set),
@@ -53,7 +56,7 @@ lmm_system_t lmm_system_new(void)
   xbt_swag_init(&(l->saturated_constraint_set),
                 xbt_swag_offset(cnst, saturated_constraint_set_hookup));
 
-  l->variable_mallocator = xbt_mallocator_new(64,
+  l->variable_mallocator = xbt_mallocator_new(65536,
                                               lmm_variable_mallocator_new_f,
                                               lmm_variable_mallocator_free_f,
                                               lmm_variable_mallocator_reset_f);
@@ -66,8 +69,12 @@ void lmm_system_free(lmm_system_t sys)
   lmm_variable_t var = NULL;
   lmm_constraint_t cnst = NULL;
 
-  while ((var = extract_variable(sys)))
+  while ((var = extract_variable(sys))) {
+    XBT_WARN
+        ("Variable %p (%d) still in LMM system when freing it: this may be a bug",
+         var, var->id_int);
     lmm_var_free(sys, var);
+  }
 
   while ((cnst = extract_constraint(sys)))
     lmm_cnst_free(sys, cnst);
@@ -79,37 +86,48 @@ void lmm_system_free(lmm_system_t sys)
 XBT_INLINE void lmm_variable_disable(lmm_system_t sys, lmm_variable_t var)
 {
   int i;
+  int n;
+
   lmm_element_t elem = NULL;
 
-  XBT_IN2("(sys=%p, var=%p)", sys, var);
+  XBT_IN("(sys=%p, var=%p)", sys, var);
   sys->modified = 1;
 
+  n = 0;
   for (i = 0; i < var->cnsts_number; i++) {
     elem = &var->cnsts[i];
     xbt_swag_remove(elem, &(elem->constraint->element_set));
     xbt_swag_remove(elem, &(elem->constraint->active_element_set));
     if (!xbt_swag_size(&(elem->constraint->element_set)))
       make_constraint_inactive(sys, elem->constraint);
-    else
-      lmm_update_modified_set(sys, elem->constraint);
+    else {
+      if (n < i)
+        var->cnsts[n].constraint = elem->constraint;
+      n++;
+    }
   }
+  if (n) {
+    var->cnsts_number = n;
+    lmm_update_modified_set(sys, var->cnsts[0].constraint);
+  }
+
   var->cnsts_number = 0;
-  XBT_OUT;
+  XBT_OUT();
 }
 
 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var)
 {
 
   lmm_variable_disable(sys, var);
-  free(var->cnsts);
   xbt_mallocator_release(sys->variable_mallocator, var);
 }
 
-static XBT_INLINE void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst)
+static XBT_INLINE void lmm_cnst_free(lmm_system_t sys,
+                                     lmm_constraint_t cnst)
 {
-/*   xbt_assert0(xbt_swag_size(&(cnst->element_set)), */
+/*   xbt_assert(xbt_swag_size(&(cnst->element_set)), */
 /* 	      "This list should be empty!"); */
-  remove_active_constraint(sys, cnst);
+  make_constraint_inactive(sys, cnst);
   free(cnst);
 }
 
@@ -145,7 +163,8 @@ XBT_INLINE int lmm_constraint_is_shared(lmm_constraint_t cnst)
   return (cnst->shared);
 }
 
-XBT_INLINE void lmm_constraint_free(lmm_system_t sys, lmm_constraint_t cnst)
+XBT_INLINE void lmm_constraint_free(lmm_system_t sys,
+                                    lmm_constraint_t cnst)
 {
   remove_constraint(sys, cnst);
   lmm_cnst_free(sys, cnst);
@@ -153,20 +172,17 @@ XBT_INLINE void lmm_constraint_free(lmm_system_t sys, lmm_constraint_t cnst)
 
 static void *lmm_variable_mallocator_new_f(void)
 {
-  return xbt_new(s_lmm_variable_t, 1);
+  lmm_variable_t var = xbt_new(s_lmm_variable_t, 1);
+  var->cnsts = NULL; /* will be created by realloc */
+  return var;
 }
 
 static void lmm_variable_mallocator_free_f(void *var)
 {
+  xbt_free(((lmm_variable_t) var)->cnsts);
   xbt_free(var);
 }
 
-static void lmm_variable_mallocator_reset_f(void *var)
-{
-  /* memset to zero like calloc */
-  memset(var, 0, sizeof(s_lmm_variable_t));
-}
-
 lmm_variable_t lmm_variable_new(lmm_system_t sys, void *id,
                                 double weight,
                                 double bound, int number_of_constraints)
@@ -174,16 +190,14 @@ lmm_variable_t lmm_variable_new(lmm_system_t sys, void *id,
   lmm_variable_t var = NULL;
   int i;
 
-  XBT_IN5("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)",
+  XBT_IN("(sys=%p, id=%p, weight=%f, bound=%f, num_cons =%d)",
           sys, id, weight, bound, number_of_constraints);
 
   var = xbt_mallocator_get(sys->variable_mallocator);
   var->id = id;
   var->id_int = Global_debug_id++;
-  var->cnsts = xbt_new0(s_lmm_element_t, number_of_constraints);
+  var->cnsts = xbt_realloc(var->cnsts, number_of_constraints * sizeof(s_lmm_element_t));
   for (i = 0; i < number_of_constraints; i++) {
-    /* Should be useless because of the 
-       calloc but it seems to help valgrind... */
     var->cnsts[i].element_set_hookup.next = NULL;
     var->cnsts[i].element_set_hookup.prev = NULL;
     var->cnsts[i].active_element_set_hookup.next = NULL;
@@ -193,22 +207,28 @@ lmm_variable_t lmm_variable_new(lmm_system_t sys, void *id,
     var->cnsts[i].value = 0.0;
   }
   var->cnsts_size = number_of_constraints;
-  var->cnsts_number = 0;        /* Should be useless because of the 
-                                   calloc but it seems to help valgrind... */
+  var->cnsts_number = 0;
   var->weight = weight;
   var->bound = bound;
   var->value = 0.0;
-
-
+  var->visited = sys->visited_counter - 1;
+  var->mu = 0.0;
+  var->new_mu = 0.0;
   var->func_f = func_f_def;
   var->func_fp = func_fp_def;
   var->func_fpi = func_fpi_def;
 
+  var->variable_set_hookup.next = NULL;
+  var->variable_set_hookup.prev = NULL;
+  var->saturated_variable_set_hookup.next = NULL;
+  var->saturated_variable_set_hookup.prev = NULL;
+
   if (weight)
     xbt_swag_insert_at_head(var, &(sys->variable_set));
   else
     xbt_swag_insert_at_tail(var, &(sys->variable_set));
-  XBT_OUT;
+
+  XBT_OUT(" returns %p", var);
   return var;
 }
 
@@ -235,7 +255,7 @@ void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
 
   sys->modified = 1;
 
-  xbt_assert0(var->cnsts_number < var->cnsts_size, "Too much constraints");
+  xbt_assert(var->cnsts_number < var->cnsts_size, "Too much constraints");
 
   elem = &(var->cnsts[var->cnsts_number++]);
 
@@ -247,9 +267,14 @@ void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
     xbt_swag_insert_at_head(elem, &(elem->constraint->element_set));
   else
     xbt_swag_insert_at_tail(elem, &(elem->constraint->element_set));
-
-  make_constraint_active(sys, cnst);
-  lmm_update_modified_set(sys, cnst);
+  if(!sys->selective_update_active) {
+    make_constraint_active(sys, cnst);
+  } else if(elem->value>0 || var->weight >0) {
+    make_constraint_active(sys, cnst);
+    lmm_update_modified_set(sys, cnst);
+    if (var->cnsts_number > 1)
+      lmm_update_modified_set(sys, var->cnsts[0].constraint);
+  }
 }
 
 void lmm_expand_add(lmm_system_t sys, lmm_constraint_t cnst,
@@ -290,7 +315,8 @@ void lmm_elem_set_value(lmm_system_t sys, lmm_constraint_t cnst,
 }
 
 XBT_INLINE lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t sys,
-                                       lmm_variable_t var, int num)
+                                                  lmm_variable_t var,
+                                                  int num)
 {
   if (num < var->cnsts_number)
     return (var->cnsts[num].constraint);
@@ -298,7 +324,18 @@ XBT_INLINE lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t sys,
     return NULL;
 }
 
-XBT_INLINE int lmm_get_number_of_cnst_from_var(lmm_system_t sys, lmm_variable_t var)
+XBT_INLINE double lmm_get_cnst_weight_from_var(lmm_system_t sys,
+                                                         lmm_variable_t var,
+                                                         int num)
+{
+  if (num < var->cnsts_number)
+    return (var->cnsts[num].value);
+  else
+    return 0.0;
+}
+
+XBT_INLINE int lmm_get_number_of_cnst_from_var(lmm_system_t sys,
+                                               lmm_variable_t var)
 {
   return (var->cnsts_number);
 }
@@ -327,35 +364,34 @@ XBT_INLINE void *lmm_variable_id(lmm_variable_t var)
   return var->id;
 }
 
-static XBT_INLINE void saturated_constraint_set_update(lmm_system_t sys,
-                                            lmm_constraint_t cnst,
-                                            double *min_usage)
+static XBT_INLINE int saturated_constraint_set_update(lmm_system_t sys,
+                                                      lmm_constraint_t
+                                                      cnst,
+                                                      double *min_usage)
 {
-  lmm_constraint_t useless_cnst = NULL;
+  volatile double usage;
 
-  XBT_IN3("sys=%p, cnst=%p, min_usage=%f", sys, cnst, *min_usage);
+  XBT_IN("sys=%p, cnst=%p, min_usage=%f", sys, cnst, *min_usage);
   if (cnst->usage <= 0) {
-    XBT_OUT;
-    return;
+    XBT_OUT();
+    return 1;
   }
   if (cnst->remaining <= 0) {
-    XBT_OUT;
-    return;
+    XBT_OUT();
+    return 1;
   }
-  if ((*min_usage < 0) || (*min_usage > cnst->remaining / cnst->usage)) {
-    *min_usage = cnst->remaining / cnst->usage;
-    LOG3(xbt_log_priority_trace,
-         "min_usage=%f (cnst->remaining=%f, cnst->usage=%f)", *min_usage,
-         cnst->remaining, cnst->usage);
-    while ((useless_cnst =
-            xbt_swag_getFirst(&(sys->saturated_constraint_set))))
-      xbt_swag_remove(useless_cnst, &(sys->saturated_constraint_set));
-
-    xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
-  } else if (*min_usage == cnst->remaining / cnst->usage) {
-    xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
+  usage = cnst->remaining / cnst->usage;
+  if (*min_usage < 0 || *min_usage > usage) {
+    *min_usage = usage;
+    XBT_HERE(" min_usage=%f (cnst->remaining=%f, cnst->usage=%f)",
+             *min_usage, cnst->remaining, cnst->usage);
+    xbt_swag_reset(&sys->saturated_constraint_set);
+    xbt_swag_insert(cnst, &sys->saturated_constraint_set);
+  } else if (*min_usage == usage) {
+    xbt_swag_insert(cnst, &sys->saturated_constraint_set);
   }
-  XBT_OUT;
+  XBT_OUT();
+  return 0;
 }
 
 static XBT_INLINE void saturated_variable_set_update(lmm_system_t sys)
@@ -394,23 +430,22 @@ void lmm_print(lmm_system_t sys)
   var_list = &(sys->variable_set);
   sprintf(print_buf, "MAX-MIN ( ");
   trace_buf =
-    xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+      xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
   strcat(trace_buf, print_buf);
   xbt_swag_foreach(var, var_list) {
     sprintf(print_buf, "'%d'(%f) ", var->id_int, var->weight);
     trace_buf =
-      xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+        xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
     strcat(trace_buf, print_buf);
   }
   sprintf(print_buf, ")");
   trace_buf =
-    xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+      xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
   strcat(trace_buf, print_buf);
-  fprintf(stderr, "%s", trace_buf);
-  //DEBUG1("%20s", trace_buf); FIXME
+  XBT_DEBUG("%20s", trace_buf);
   trace_buf[0] = '\000';
 
-  DEBUG0("Constraints");
+  XBT_DEBUG("Constraints");
   /* Printing Constraints */
   cnst_list = &(sys->active_constraint_set);
   xbt_swag_foreach(cnst, cnst_list) {
@@ -418,46 +453,55 @@ void lmm_print(lmm_system_t sys)
     elem_list = &(cnst->element_set);
     sprintf(print_buf, "\t");
     trace_buf =
-      xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+        xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
     strcat(trace_buf, print_buf);
+    sprintf(print_buf, "%s(",(cnst->shared)?"":"max");
+    trace_buf =
+      xbt_realloc(trace_buf,
+		  strlen(trace_buf) + strlen(print_buf) + 1);
+    strcat(trace_buf, print_buf);      
     xbt_swag_foreach(elem, elem_list) {
-      sprintf(print_buf, "%f.'%d'(%f) + ", elem->value,
-              elem->variable->id_int, elem->variable->value);
+      sprintf(print_buf, "%f.'%d'(%f) %s ", elem->value,
+              elem->variable->id_int, elem->variable->value,(cnst->shared)?"+":",");
       trace_buf =
-        xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+          xbt_realloc(trace_buf,
+                      strlen(trace_buf) + strlen(print_buf) + 1);
       strcat(trace_buf, print_buf);
-      sum += elem->value * elem->variable->value;
+      if(cnst->shared) 
+	sum += elem->value * elem->variable->value;
+      else 
+	sum = MAX(sum,elem->value * elem->variable->value);
     }
-    sprintf(print_buf, "0 <= %f ('%d')", cnst->bound, cnst->id_int);
+    sprintf(print_buf, "0) <= %f ('%d')", cnst->bound, cnst->id_int);
     trace_buf =
-      xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+        xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
     strcat(trace_buf, print_buf);
 
     if (!cnst->shared) {
       sprintf(print_buf, " [MAX-Constraint]");
       trace_buf =
-        xbt_realloc(trace_buf, strlen(trace_buf) + strlen(print_buf) + 1);
+          xbt_realloc(trace_buf,
+                      strlen(trace_buf) + strlen(print_buf) + 1);
       strcat(trace_buf, print_buf);
     }
-    //   DEBUG1("%s", trace_buf);
-    fprintf(stderr, "%s", trace_buf);
+    XBT_DEBUG("%s", trace_buf);
     trace_buf[0] = '\000';
-    xbt_assert3(!double_positive(sum - cnst->bound),
+    xbt_assert(!double_positive(sum - cnst->bound),
                 "Incorrect value (%f is not smaller than %f): %g",
                 sum, cnst->bound, sum - cnst->bound);
   }
 
-  DEBUG0("Variables");
+  XBT_DEBUG("Variables");
   /* Printing Result */
   xbt_swag_foreach(var, var_list) {
     if (var->bound > 0) {
-      DEBUG4("'%d'(%f) : %f (<=%f)", var->id_int, var->weight, var->value,
+      XBT_DEBUG("'%d'(%f) : %f (<=%f)", var->id_int, var->weight, var->value,
              var->bound);
-      xbt_assert2(!double_positive(var->value - var->bound),
+      xbt_assert(!double_positive(var->value - var->bound),
                   "Incorrect value (%f is not smaller than %f",
                   var->value, var->bound);
     } else {
-      DEBUG3("'%d'(%f) : %f", var->id_int, var->weight, var->value);
+      XBT_DEBUG("'%d'(%f) : %f", var->id_int, var->weight, var->value);
     }
   }
 
@@ -468,6 +512,7 @@ void lmm_solve(lmm_system_t sys)
 {
   lmm_variable_t var = NULL;
   lmm_constraint_t cnst = NULL;
+  lmm_constraint_t cnst_next = NULL;
   lmm_element_t elem = NULL;
   xbt_swag_t cnst_list = NULL;
   xbt_swag_t var_list = NULL;
@@ -478,17 +523,21 @@ void lmm_solve(lmm_system_t sys)
   if (!(sys->modified))
     return;
 
+  XBT_IN("(sys=%p)", sys);
+
   /*
    * Compute Usage and store the variables that reach the maximum.
    */
-  cnst_list = sys->selective_update_active ? &(sys->modified_constraint_set) :
-    &(sys->active_constraint_set);
+  cnst_list =
+      sys->
+      selective_update_active ? &(sys->modified_constraint_set) :
+      &(sys->active_constraint_set);
 
-  DEBUG1("Active constraints : %d", xbt_swag_size(cnst_list));
+  XBT_DEBUG("Active constraints : %d", xbt_swag_size(cnst_list));
   /* Init: Only modified code portions */
   xbt_swag_foreach(cnst, cnst_list) {
     elem_list = &(cnst->element_set);
-    //DEBUG1("Variable set : %d", xbt_swag_size(elem_list));
+    //XBT_DEBUG("Variable set : %d", xbt_swag_size(elem_list));
     xbt_swag_foreach(elem, elem_list) {
       var = elem->variable;
       if (var->weight <= 0.0)
@@ -497,10 +546,11 @@ void lmm_solve(lmm_system_t sys)
     }
   }
 
-  DEBUG1("Active constraints : %d", xbt_swag_size(cnst_list));
-  xbt_swag_foreach(cnst, cnst_list) {
+  xbt_swag_foreach_safe(cnst, cnst_next, cnst_list) {
     /* INIT */
     cnst->remaining = cnst->bound;
+    if (cnst->remaining == 0)
+      continue;
     cnst->usage = 0;
     elem_list = &(cnst->element_set);
     xbt_swag_foreach(elem, elem_list) {
@@ -514,12 +564,28 @@ void lmm_solve(lmm_system_t sys)
           cnst->usage = elem->value / elem->variable->weight;
 
         make_elem_active(elem);
+        if (sys->keep_track)
+          xbt_swag_insert(elem->variable->id, sys->keep_track);
       }
     }
-    DEBUG2("Constraint Usage %d : %f", cnst->id_int, cnst->usage);
+    XBT_DEBUG("Constraint Usage '%d' : %f", cnst->id_int, cnst->usage);
     /* Saturated constraints update */
+    if(cnst->usage>0) {
+      // TODO Créer une contrainte light
+      // À partir de maintenant, usage et remaining sont dans cnst_light uniquement.
+      // En fait, usage et remaining doivent disparaitre complètement de cnst pour n'être que dans cnst_light.
+      xbt_swag_remove(cnst, cnst_list);
+      xbt_swag_insert_at_head(cnst, cnst_list);
+    }
+    // On a deux dynars:
+    //    - Celui de cnst_list avec les csnt_light
+    //    - saturated_constraint_set, celui des indexes de cnst_list qui sont saturées
+    // Si la cnst_light est un minimum_usage on la met dans saturated_constraint_set
     saturated_constraint_set_update(sys, cnst, &min_usage);
   }
+  // On parcours saturated_constraint_set (le tableau d'index) dans le sens décroissant
+  //   - on accède aux contraintes correspondantes pour mettre les variables dans saturated_variable_set
+  //   - on se permutte si besoin avec le dernier élément; on enlève le dernier élément de cnst_list
   saturated_variable_set_update(sys);
 
   /* Saturated variables update */
@@ -533,16 +599,16 @@ void lmm_solve(lmm_system_t sys)
         DIE_IMPOSSIBLE;
       /* First check if some of these variables have reach their upper
          bound and update min_usage accordingly. */
-      DEBUG5
-        ("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f",
-         var->id_int, var->bound, var->weight, min_usage,
-         var->bound * var->weight);
+      XBT_DEBUG
+          ("var=%d, var->bound=%f, var->weight=%f, min_usage=%f, var->bound*var->weight=%f",
+           var->id_int, var->bound, var->weight, min_usage,
+           var->bound * var->weight);
       if ((var->bound > 0) && (var->bound * var->weight < min_usage)) {
         if (min_bound < 0)
           min_bound = var->bound;
         else
           min_bound = MIN(min_bound, var->bound);
-        DEBUG1("Updated min_bound=%f", min_bound);
+        XBT_DEBUG("Updated min_bound=%f", min_bound);
       }
     }
 
@@ -560,7 +626,7 @@ void lmm_solve(lmm_system_t sys)
           continue;
         }
       }
-      DEBUG5("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ",
+      XBT_DEBUG("Min usage: %f, Var(%d)->weight: %f, Var(%d)->value: %f ",
              min_usage, var->id_int, var->weight, var->id_int, var->value);
 
 
@@ -572,6 +638,10 @@ void lmm_solve(lmm_system_t sys)
         if (cnst->shared) {
           double_update(&(cnst->remaining), elem->value * var->value);
           double_update(&(cnst->usage), elem->value / var->weight);
+          if(cnst->usage<=0 || cnst->remaining<=0) {
+            xbt_swag_remove(cnst, cnst_list);
+            xbt_swag_insert_at_tail(cnst, cnst_list);
+          }
           make_elem_inactive(elem);
         } else {                /* FIXME one day: We recompute usage.... :( */
           cnst->usage = 0.0;
@@ -583,8 +653,10 @@ void lmm_solve(lmm_system_t sys)
             if (elem->variable->value > 0)
               break;
             if ((elem->value > 0)) {
-              cnst->usage=MAX(cnst->usage,elem->value / elem->variable->weight);
-              DEBUG2("Constraint Usage %d : %f", cnst->id_int, cnst->usage);
+              cnst->usage =
+                  MAX(cnst->usage, elem->value / elem->variable->weight);
+              XBT_DEBUG("Constraint Usage %d : %f", cnst->id_int,
+                     cnst->usage);
               make_elem_active(elem);
             }
           }
@@ -594,13 +666,11 @@ void lmm_solve(lmm_system_t sys)
     }
 
     /* Find out which variables reach the maximum */
-    cnst_list =
-      sys->selective_update_active ? &(sys->modified_constraint_set) :
-      &(sys->active_constraint_set);
     min_usage = -1;
     min_bound = -1;
+
     xbt_swag_foreach(cnst, cnst_list) {
-      saturated_constraint_set_update(sys, cnst, &min_usage);
+      if(saturated_constraint_set_update(sys, cnst, &min_usage)) break;
     }
     saturated_variable_set_update(sys);
 
@@ -613,6 +683,7 @@ void lmm_solve(lmm_system_t sys)
   if (XBT_LOG_ISENABLED(surf_maxmin, xbt_log_priority_debug)) {
     lmm_print(sys);
   }
+  XBT_OUT();
 }
 
 /* Not a O(1) function */
@@ -646,14 +717,11 @@ void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
 void lmm_update_variable_bound(lmm_system_t sys, lmm_variable_t var,
                                double bound)
 {
-  int i;
-
   sys->modified = 1;
   var->bound = bound;
 
-  for (i = 0; i < var->cnsts_number; i++)
-    lmm_update_modified_set(sys, var->cnsts[i].constraint);
-
+  if (var->cnsts_number)
+    lmm_update_modified_set(sys, var->cnsts[0].constraint);
 }
 
 
@@ -665,7 +733,7 @@ void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var,
 
   if (weight == var->weight)
     return;
-  XBT_IN3("(sys=%p, var=%p, weight=%f)", sys, var, weight);
+  XBT_IN("(sys=%p, var=%p, weight=%f)", sys, var, weight);
   sys->modified = 1;
   var->weight = weight;
   xbt_swag_remove(var, &(sys->variable_set));
@@ -682,12 +750,13 @@ void lmm_update_variable_weight(lmm_system_t sys, lmm_variable_t var,
     else
       xbt_swag_insert_at_tail(elem, &(elem->constraint->element_set));
 
-    lmm_update_modified_set(sys, elem->constraint);
+    if (i == 0)
+      lmm_update_modified_set(sys, elem->constraint);
   }
   if (!weight)
     var->value = 0.0;
 
-  XBT_OUT;
+  XBT_OUT();
 }
 
 XBT_INLINE double lmm_get_variable_weight(lmm_variable_t var)
@@ -695,8 +764,9 @@ XBT_INLINE double lmm_get_variable_weight(lmm_variable_t var)
   return var->weight;
 }
 
-XBT_INLINE void lmm_update_constraint_bound(lmm_system_t sys, lmm_constraint_t cnst,
-                                 double bound)
+XBT_INLINE void lmm_update_constraint_bound(lmm_system_t sys,
+                                            lmm_constraint_t cnst,
+                                            double bound)
 {
   sys->modified = 1;
   lmm_update_modified_set(sys, cnst);
@@ -708,17 +778,28 @@ XBT_INLINE int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
   return xbt_swag_belongs(cnst, &(sys->active_constraint_set));
 }
 
-XBT_INLINE lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t sys)
+XBT_INLINE lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t
+                                                            sys)
 {
   return xbt_swag_getFirst(&(sys->active_constraint_set));
 }
 
-XBT_INLINE lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t sys,
-                                                lmm_constraint_t cnst)
+XBT_INLINE lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t
+                                                           sys,
+                                                           lmm_constraint_t
+                                                           cnst)
 {
   return xbt_swag_getNext(cnst, (sys->active_constraint_set).offset);
 }
 
+#ifdef HAVE_LATENCY_BOUND_TRACKING
+XBT_INLINE int lmm_is_variable_limited_by_latency(lmm_variable_t var)
+{
+  return (double_equals(var->bound, var->value));
+}
+#endif
+
+
 /** \brief Update the constraint set propagating recursively to
  *  other constraints so the system should not be entirely computed.
  *
@@ -729,35 +810,36 @@ XBT_INLINE lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t sys,
  *  constraints that have changed. Each constraint change is propagated
  *  to the list of constraints for each variable.
  */
-static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst)
+static void lmm_update_modified_set_rec(lmm_system_t sys,
+                                        lmm_constraint_t cnst)
 {
-  lmm_element_t elem = NULL;
-  lmm_variable_t var = NULL;
-  xbt_swag_t elem_list = NULL;
-  int i;
-
-  /* return if selective update isn't active */
-  if (!sys->selective_update_active)
-    return;
-
-  //DEBUG1("Updating modified constraint set with constraint %d", cnst->id_int);
-
-  if (xbt_swag_belongs(cnst, &(sys->modified_constraint_set)))
-    return;
-
-  //DEBUG1("Inserting into modified constraint set %d", cnst->id_int);
-
-  /* add to modified set */
-  xbt_swag_insert(cnst, &(sys->modified_constraint_set));
+  lmm_element_t elem;
 
-  elem_list = &(cnst->element_set);
-  xbt_swag_foreach(elem, elem_list) {
-    var = elem->variable;
-    for (i = 0; i < var->cnsts_number; i++)
-      if (cnst != var->cnsts[i].constraint) {
-        //DEBUG2("Updating modified %d calling for %d", cnst->id_int, var->cnsts[i].constraint->id_int);
-        lmm_update_modified_set(sys, var->cnsts[i].constraint);
+  xbt_swag_foreach(elem, &cnst->element_set) {
+    lmm_variable_t var = elem->variable;
+    s_lmm_element_t *cnsts = var->cnsts;
+    int i;
+    for (i = 0; var->visited != sys->visited_counter
+             && i < var->cnsts_number ; i++) {
+      if (cnsts[i].constraint != cnst
+          && !xbt_swag_belongs(cnsts[i].constraint,
+                               &sys->modified_constraint_set)) {
+        xbt_swag_insert(cnsts[i].constraint, &sys->modified_constraint_set);
+        lmm_update_modified_set_rec(sys, cnsts[i].constraint);
       }
+    }
+    var->visited = sys->visited_counter;
+  }
+}
+
+static void lmm_update_modified_set(lmm_system_t sys,
+                                    lmm_constraint_t cnst)
+{
+  /* nothing to do if selective update isn't active */
+  if (sys->selective_update_active
+      && !xbt_swag_belongs(cnst, &sys->modified_constraint_set)) {
+    xbt_swag_insert(cnst, &sys->modified_constraint_set);
+    lmm_update_modified_set_rec(sys, cnst);
   }
 }
 
@@ -767,12 +849,11 @@ static void lmm_update_modified_set(lmm_system_t sys, lmm_constraint_t cnst)
  */
 static void lmm_remove_all_modified_set(lmm_system_t sys)
 {
-  lmm_element_t elem = NULL;
-  lmm_element_t elem_next = NULL;
-  xbt_swag_t elem_list = NULL;
-
-  elem_list = &(sys->modified_constraint_set);
-  xbt_swag_foreach_safe(elem, elem_next, elem_list) {
-    xbt_swag_remove(elem, elem_list);
+  if (++sys->visited_counter == 1) {
+    /* the counter wrapped around, reset each variable->visited */
+    lmm_variable_t var;
+    xbt_swag_foreach(var, &sys->variable_set)
+      var->visited = 0;
   }
+  xbt_swag_reset(&sys->modified_constraint_set);
 }