From: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Date: Tue, 21 Dec 2010 16:59:21 +0000 (+0100)
Subject: Display load average and standard deviation at the end.
X-Git-Tag: v0.1~211
X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/loba.git/commitdiff_plain/50a00235743c59840ee2db2258e9e6dd7444f646?hp=465f6a6ac2920b233da310a94fbbf055095f6eb9

Display load average and standard deviation at the end.
---

diff --git a/TODO b/TODO
index 1d5fe42..09559ef 100644
--- a/TODO
+++ b/TODO
@@ -4,8 +4,6 @@
 
 * implement loba_* algorithms (start with some trivial one)
 
-* add some statistics about load (im)balance at the end of the simulation?
-
 * for automatic process topology,
    -> implement some random initial distribution of load
 
diff --git a/main.cpp b/main.cpp
index 01bf3ac..5326e73 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,9 @@
+#include <cmath>
 #include <cstring>
 #include <iostream>
+#include <numeric>
 #include <stdexcept>
+#include <vector>
 #include <msg/msg.h>
 #include <xbt/log.h>
 
@@ -22,22 +25,29 @@ XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(main);
 #include "timer.h"
 #include "version.h"
 
-// Failure exit status
-enum {
-    EXIT_NO_FAILURE    = 0x00,  // no error
-    EXIT_FAILURE_ARGS  = 0x01,  // bad arguments
-    EXIT_FAILURE_INIT  = 0x02,  // failed to initialize simulator
-    EXIT_FAILURE_SIMU  = 0x04,  // simulation failed
-    EXIT_FAILURE_CLEAN = 0x08,  // error at cleanup
-};
+namespace {
+    // Failure exit status
+    enum {
+        EXIT_NO_FAILURE    = 0x00,  // no error
+        EXIT_FAILURE_ARGS  = 0x01,  // bad arguments
+        EXIT_FAILURE_INIT  = 0x02,  // failed to initialize simulator
+        EXIT_FAILURE_SIMU  = 0x04,  // simulation failed
+        EXIT_FAILURE_CLEAN = 0x08,  // error at cleanup
+    };
+
+    std::vector<double> loads;
+    double load_stddev;
+    double load_avg;
+}
 
-int simulation_main(int argc, char* argv[])
+static int simulation_main(int argc, char* argv[])
 {
     int result;
     process* proc;
     try {
         proc = opt::loba_algorithms.new_instance(opt::loba_algo, argc, argv);
         result = proc->run();
+        loads.push_back(proc->get_load());
         delete proc;
     }
     catch (std::invalid_argument& e) {
@@ -46,7 +56,7 @@ int simulation_main(int argc, char* argv[])
     return result;
 }
 
-void check_for_lost_load()
+static void check_for_lost_load()
 {
     double total_init = process::get_total_load_init();
 
@@ -75,6 +85,21 @@ void check_for_lost_load()
                total_running, running_ratio);
 }
 
+static void compute_load_imbalance()
+{
+    unsigned n = loads.size();
+    load_avg = std::accumulate(loads.begin(), loads.end(), 0.0) / n;
+    double variance = 0.0;
+    double epsilon = 0.0;
+    for (unsigned i = 0 ; i < n ; ++i) {
+        double diff = loads[i] - load_avg;
+        variance += diff * diff;
+        epsilon += diff;
+    }
+    variance = (variance - (epsilon * epsilon) / n) / n;
+    load_stddev = sqrt(variance);
+}
+
 int main(int argc, char* argv[])
 {
     // Note: variables used after THROW must be declared as volatile.
@@ -153,6 +178,7 @@ int main(int argc, char* argv[])
         simulated_time = MSG_get_clock();
         INFO1("Simulation ended at %f.", simulated_time);
         check_for_lost_load();
+        compute_load_imbalance();
         if (res != MSG_OK)
             THROW1(0, 0, "MSG_main() failed with status %#x", res);
 
@@ -179,8 +205,9 @@ int main(int argc, char* argv[])
     if (simulated_time >= 0.0) {
         simulation_time.stop();
         INFO0(",----[ Results ]");
-        INFO1("| Total simulated time...: %g", simulated_time);
-        INFO1("| Total simulation time..: %g", simulation_time.duration());
+        INFO2("| Load avg./stddev. at exit.: %g / %g", load_avg, load_stddev);
+        INFO1("| Total simulated time......: %g", simulated_time);
+        INFO1("| Total simulation time.....: %g", simulation_time.duration());
         INFO0("`----");
     }
     if (exit_status)
diff --git a/process.h b/process.h
index 4e6ab24..c72fdf2 100644
--- a/process.h
+++ b/process.h
@@ -26,6 +26,8 @@ public:
     process(int argc, char* argv[]);
     virtual ~process();
 
+    double get_load() const                { return load; }
+
     int run();
 
 protected: