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[simgrid.git] / src / surf / plugins / host_load.cpp

diff --git a/src/surf/plugins/host_load.cpp b/src/surf/plugins/host_load.cpp
index 71e8bf0..31ea874 100644 (file)
--- a/src/surf/plugins/host_load.cpp
+++ b/src/surf/plugins/host_load.cpp
@@ -37,6 +37,7 @@ public:
   double getCurrentLoad();
   double getComputedFlops();
   double getAverageLoad();
+  double getIdleTime();
   void update();
   void reset();
 
@@ -44,8 +45,12 @@ private:
   simgrid::s4u::Host* host = nullptr;
   double last_updated      = 0;
   double last_reset        = 0;
+  double current_speed     = 0;
   double current_flops     = 0;
   double computed_flops    = 0;
+  double idle_time         = 0;
+  double theor_max_flops   = 0;
+  bool   was_prev_idle     = true; /* A host is idle at the beginning */
 };
 
 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
@@ -54,7 +59,10 @@ HostLoad::HostLoad(simgrid::s4u::Host* ptr)
     : host(ptr)
     , last_updated(surf_get_clock())
     , last_reset(surf_get_clock())
+    , current_speed(host->getSpeed())
     , current_flops(host->pimpl_cpu->constraint()->get_usage())
+    , theor_max_flops(0)
+    , was_prev_idle(current_flops == 0)
 {
 }
 
@@ -63,31 +71,59 @@ HostLoad::~HostLoad() = default;
 void HostLoad::update()
 {
   double now = surf_get_clock();
-  if (last_updated < now) {
-    /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k \in {0, 1, ..., cores}
-     * number of active cores */
-    current_flops = host->pimpl_cpu->constraint()->get_usage();
-
-    /* flops == pstate_speed * cores_being_currently_used */
-    computed_flops += (now - last_updated) * current_flops;
-    last_updated = now;
+
+  /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k \in {0, 1, ..., cores}
+   * number of active cores */
+  current_flops = host->pimpl_cpu->constraint()->get_usage();
+
+  /* flops == pstate_speed * cores_being_currently_used */
+  computed_flops += (now - last_updated) * current_flops;
+
+  if (was_prev_idle) {
+    idle_time += (now - last_updated);
   }
+
+  theor_max_flops += current_speed * host->getCoreCount() * (now - last_updated);
+  current_speed    = host->getSpeed();
+  last_updated     = now;
+  was_prev_idle    = (current_flops == 0);
 }
 
+/**
+ * WARNING: This function does not guarantee that you have the real load at any time
+ * imagine all actions on your CPU terminate at time t. Your load is then 0. Then
+ * you query the load (still 0) and then another action starts (still at time t!).
+ * This means that the load was never really 0 (because the time didn't advance) but
+ * it will still be reported as 0.
+ *
+ * So, use at your own risk.
+ */
 double HostLoad::getCurrentLoad()
 {
-  return current_flops / (host->getSpeed() * host->getCoreCount());
+  // We don't need to call update() here because it is called everytime an
+  // action terminates or starts
+  // FIXME: Can this happen at the same time? stop -> call to getCurrentLoad, load = 0 -> next action starts?
+  return current_flops / static_cast<double>(host->getSpeed() * host->getCoreCount());
+}
+
+/**
+ * Return idle time since last reset
+ */
+double HostLoad::getIdleTime() {
+  return idle_time;
 }
 
 double HostLoad::getAverageLoad()
 {
-  return getComputedFlops() / (host->getSpeed() * host->getCoreCount() * (surf_get_clock() - last_reset));
+  if (theor_max_flops == 0) { // Avoid division by 0
+    return 0;
+  }
+
+  return computed_flops / theor_max_flops;
 }
 
 double HostLoad::getComputedFlops()
 {
-  update();
-
   return computed_flops;
 }
 
@@ -96,9 +132,14 @@ double HostLoad::getComputedFlops()
  */
 void HostLoad::reset()
 {
-  last_updated   = surf_get_clock();
-  last_reset     = surf_get_clock();
-  computed_flops = 0;
+  last_updated    = surf_get_clock();
+  last_reset      = surf_get_clock();
+  idle_time       = 0;
+  computed_flops  = 0;
+  theor_max_flops = 0;
+  current_flops   = host->pimpl_cpu->constraint()->get_usage();
+  current_speed   = host->getSpeed();
+  was_prev_idle   = (current_flops == 0);
 }
 }
 }
@@ -122,10 +163,11 @@ static void onActionStateChange(simgrid::surf::CpuAction* action, simgrid::surf:
   for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
     simgrid::s4u::Host* host = cpu->getHost();
 
+    if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host)) // Ignore virtual machines
+      return;
+
     if (host != nullptr) {
-      // Get the host_load extension for the relevant host
-      HostLoad* host_load = host->extension<HostLoad>();
-      host_load->update();
+      host->extension<HostLoad>()->update();
     }
   }
 }
@@ -169,6 +211,30 @@ double sg_host_get_current_load(sg_host_t host)
   return host->extension<HostLoad>()->getCurrentLoad();
 }
 
+/** @brief Returns the current load of the host passed as argument
+ *
+ *  See also @ref plugin_load
+ */
+double sg_host_get_avg_load(sg_host_t host)
+{
+  xbt_assert(HostLoad::EXTENSION_ID.valid(),
+             "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
+
+  return host->extension<HostLoad>()->getAverageLoad();
+}
+
+/** @brief Returns the time this host was idle since the last reset
+ *
+ *  See also @ref plugin_load
+ */
+double sg_host_get_idle_time(sg_host_t host)
+{
+  xbt_assert(HostLoad::EXTENSION_ID.valid(),
+             "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
+
+  return host->extension<HostLoad>()->getIdleTime();
+}
+
 double sg_host_get_computed_flops(sg_host_t host)
 {
   xbt_assert(HostLoad::EXTENSION_ID.valid(),