[HostLoad] Update comments + add debug statement

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

diff --git a/src/plugins/host_load.cpp b/src/plugins/host_load.cpp
index dd1d428..5387b3c 100644 (file)
--- a/src/plugins/host_load.cpp
+++ b/src/plugins/host_load.cpp
@@ -3,9 +3,12 @@
 /* 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 <simgrid/s4u.hpp>
 #include "simgrid/plugins/load.h"
+#include "src/include/surf/surf.hpp"
 #include "src/plugins/vm/VirtualMachineImpl.hpp"
+#include <simgrid/s4u.hpp>
+
+SIMGRID_REGISTER_PLUGIN(host_load, "Cpu load", &sg_host_load_plugin_init)
 
 /** @addtogroup plugin_load
 
@@ -29,7 +32,6 @@ public:
       , current_speed_(host_->get_speed())
       , current_flops_(host_->pimpl_cpu->get_constraint()->get_usage())
       , theor_max_flops_(0)
-      , was_prev_idle_(current_flops_ == 0)
   {
   }
   ~HostLoad() = default;
@@ -41,6 +43,7 @@ public:
   double get_average_load() { return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
   double get_computed_flops() { return computed_flops_; }
   double get_idle_time() { return idle_time_; } /** Return idle time since last reset */
+  double get_total_idle_time() { return total_idle_time_; } /** Return idle time over the whole simulation */
   void update();
   void reset();
 
@@ -49,7 +52,8 @@ private:
   double last_updated_      = 0;
   double last_reset_        = 0;
   /**
-   * current_speed each core is running at right now
+   * current_speed each core is running at; we need to store this as the speed
+   * will already have changed once we get notified
    */
   double current_speed_     = 0;
   /**
@@ -59,8 +63,8 @@ private:
   double current_flops_     = 0;
   double computed_flops_    = 0;
   double idle_time_         = 0;
+  double total_idle_time_   = 0; /* This gets never reset */
   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;
@@ -69,21 +73,22 @@ void HostLoad::update()
 {
   double now = surf_get_clock();
 
-  /* 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 flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k @in {0, 1, ..., cores-1}
+   * designates number of active cores; will be 0 if CPU is currently idle */
   current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
 
   /* flops == pstate_speed * cores_being_currently_used */
   computed_flops_ += (now - last_updated_) * current_flops_;
 
-  if (was_prev_idle_) {
+  if (current_flops_ == 0) {
     idle_time_ += (now - last_updated_);
+    total_idle_time_ += (now - last_updated_);
+    XBT_DEBUG("[%s]: Currently idle -> Added %f seconds to idle time (totaling %fs)", host_->get_cname(), (now - last_updated_), idle_time_);
   }
 
   theor_max_flops_ += current_speed_ * host_->get_core_count() * (now - last_updated_);
   current_speed_ = host_->get_speed();
   last_updated_  = now;
-  was_prev_idle_ = (current_flops_ == 0);
 }
 
 /**
@@ -113,7 +118,6 @@ void HostLoad::reset()
   theor_max_flops_ = 0;
   current_flops_   = host_->pimpl_cpu->get_constraint()->get_usage();
   current_speed_   = host_->get_speed();
-  was_prev_idle_   = (current_flops_ == 0);
 }
 } // namespace plugin
 } // namespace simgrid
@@ -132,7 +136,7 @@ static void on_host_change(simgrid::s4u::Host& host)
 }
 
 /* This callback is called when an action (computation, idle, ...) terminates */
-static void on_action_state_change(simgrid::surf::CpuAction* action)
+static void on_action_state_change(simgrid::surf::CpuAction* action, simgrid::kernel::resource::Action::State /*previous*/)
 {
   for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
     simgrid::s4u::Host* host = cpu->get_host();
@@ -148,9 +152,9 @@ static void on_action_state_change(simgrid::surf::CpuAction* action)
 
 /* **************************** Public interface *************************** */
 
-/** \ingroup plugin_load
- * \brief Initializes the HostLoad plugin
- * \details The HostLoad plugin provides an API to get the current load of each host.
+/** @ingroup plugin_load
+ * @brief Initializes the HostLoad plugin
+ * @details The HostLoad plugin provides an API to get the current load of each host.
  */
 void sg_host_load_plugin_init()
 {
@@ -216,6 +220,14 @@ double sg_host_get_idle_time(sg_host_t host)
   return host->extension<HostLoad>()->get_idle_time();
 }
 
+double sg_host_get_total_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>()->get_total_idle_time();
+}
+
 double sg_host_get_computed_flops(sg_host_t host)
 {
   xbt_assert(HostLoad::EXTENSION_ID.valid(),