]> AND Private Git Repository - loba.git/blobdiff - process.cpp
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Private GIT Repository
Document a bug with parallel executions.
[loba.git] / process.cpp
index 8a73f3865c34e023c045df04759fefa2d1652efd..c85b6051a6a4224452f22ddce086740f310ed61e 100644 (file)
@@ -1,4 +1,5 @@
 #include <algorithm>
+#include <cmath>
 #include <functional>
 #include <iterator>
 #include <numeric>
@@ -19,6 +20,10 @@ double process::total_load_init = 0.0;
 double process::total_load_running = 0.0;
 double process::total_load_exit = 0.0;
 
+int process::process_counter = 0;
+double process::total_load_average;
+double process::load_diff_threshold;
+
 namespace {
 
     void sleep_until_date(double& date, double duration)
@@ -36,6 +41,13 @@ process::process(int argc, char* argv[])
     if (argc < 2 || !(std::istringstream(argv[1]) >> real_load))
         throw std::invalid_argument("bad or missing initial load parameter");
 
+    double iload = std::trunc(real_load);
+    if (opt::integer_transfer && real_load != iload) {
+        XBT_WARN("Initial load %g is not an integer.  Truncate it.",
+                 real_load);
+        real_load = iload;
+    }
+
     neigh.assign(argv + 2, argv + argc);
 
     pneigh.reserve(neigh.size());
@@ -46,16 +58,28 @@ process::process(int argc, char* argv[])
         rev_neigh.insert(std::make_pair(host, ptr));
     }
 
+    // Note: there should not be race condition with the current
+    // version of Simgrid, when updating the global variables.
+
     prev_load_broadcast = -1;   // force sending of load on first send_all()
     expected_load = real_load;
     total_load_running += real_load;
     total_load_init += real_load;
+    received_load = 0.0;
+
+    idle_duration = 0.0;
+    convergence = -1.0;
+
+    process_counter++;
+    total_load_average = total_load_running / process_counter;
+    load_diff_threshold = (opt::load_ratio_threshold +
+                           opt::avg_load_ratio * total_load_average) / 100.0;
 
     ctrl_close_pending = data_close_pending = neigh.size();
     close_received = false;
     finalizing = false;
 
-    comp_iter = lb_iter = 0;
+    all_comp_iter = comp_iter = lb_iter = 0;
 
     lb_thread = new_msg_thread("loba",
                                std::bind(&process::load_balance_loop, this));
@@ -80,12 +104,36 @@ process::~process()
 {
     delete lb_thread;
     total_load_exit += real_load;
+    xbt_assert(received_load == 0.0,
+               "received_load is %g, but should be 0.0 !", received_load);
     if (opt::log_rate < 0)
         return;
-    XBT_INFO("Final load after %d:%d iterations: %g",
-             lb_iter, comp_iter, real_load);
+    XBT_INFO("Final load after %d:%d:%d iterations: %g",
+             lb_iter, comp_iter, all_comp_iter, real_load);
+    if (convergence >= 0.0)
+        XBT_INFO("Convergence within %g%% was achieved at time %g",
+                 opt::avg_load_ratio, convergence);
+    else
+        XBT_INFO("Convergence within %g%% was not achieved",
+                 opt::avg_load_ratio);
     XBT_VERB("Expected load was: %g", expected_load);
     XBT_VERB("Total computation for this process: %g", get_comp_amount());
+    print_loads(true, xbt_log_priority_debug);
+}
+
+double process::get_iter_deviation() const
+{
+    double average_cost = opt::comp_cost(total_load_average);
+    // Do not count idle periods
+    double comp_iter_opt = acc.comp_amount / average_cost;
+/*
+    // Add iterations that could have been achieved while beeing idle
+    // (kept for documentation)
+    double self_speed = MSG_get_host_speed(MSG_host_self());
+    double average_duration = average_cost / self_speed;
+    comp_iter_opt += idle_duration / average_duration;
+*/
+    return comp_iter - comp_iter_opt;
 }
 
 int process::run()
@@ -124,13 +172,16 @@ void process::load_balance_loop()
             ++lb_iter;
         }
 
+        ctrl_receive(0.0);
+
         mutex.acquire();
         if (!opt::bookkeeping)
             expected_load = real_load - get_sum_of_to_send();
         // nothing to do with opt::bookkeeping
 
         if (opt::log_rate && lb_iter % opt::log_rate == 0) {
-            XBT_INFO("(%u:%u) current load: %g", lb_iter, comp_iter, real_load);
+            XBT_INFO("(%u:%u:%u) current load: %g",
+                     lb_iter, comp_iter, all_comp_iter, real_load);
             XBT_VERB("... expected load: %g", expected_load);
         }
 
@@ -147,7 +198,6 @@ void process::load_balance_loop()
         mutex.release();
 
         sleep_until_date(next_iter_after_date, opt::min_lb_iter_duration);
-        ctrl_receive(0.0);
     }
 
     XBT_VERB("Going to finalize for %s...", __func__);
@@ -168,26 +218,30 @@ void process::compute_loop()
     using std::placeholders::_1;
 
     double next_iter_after_date = MSG_get_clock() + opt::min_comp_iter_duration;
+    double idle_since_date = 0.0;
     while (still_running()) {
         // receive
-        mutex.acquire();
-        if (real_load > 0.0)
-            data_receive(0.0);
-        else
-            data_receive(opt::min_comp_iter_duration);
-        mutex.release();
+        // if there is something to compute, do not block
+        // else, block the duration of an *lb* iteration
+        data_receive(real_load > 0.0 ? 0.0 : opt::min_lb_iter_duration);
 
         // send
         comm.data_flush(false);
         mutex.acquire();
+        real_load += received_load;
+        received_load = 0.0;
         std::for_each(neigh.begin(), neigh.end(),
                       std::bind(&process::data_send, this, _1));
         mutex.release();
 
+        ++all_comp_iter;
         if (real_load == 0.0)
             continue;
 
+        convergence_check();
+
         // compute
+        idle_duration += MSG_get_clock() - idle_since_date;
         ++comp_iter;
         double flops = opt::comp_cost(real_load);
         m_task_t task = MSG_task_create("computation", flops, 0.0, NULL);
@@ -197,12 +251,14 @@ void process::compute_loop()
         add_comp_amount(flops);
         MSG_task_destroy(task);
 
+        idle_since_date = MSG_get_clock();
+
         sleep_until_date(next_iter_after_date, opt::min_comp_iter_duration);
     }
 
     XBT_VERB("Going to finalize for %s...", __func__);
+    // Note: idle duration is not counted during finalization
     finalizing = true;
-    total_load_running -= real_load;
     XBT_DEBUG("send DATA_CLOSE to %zu neighbor%s",
               neigh.size(), ESSE(neigh.size()));
     std::for_each(neigh.begin(), neigh.end(),
@@ -212,9 +268,33 @@ void process::compute_loop()
         XBT_DEBUG("waiting for %d DATA_CLOSE", data_close_pending);
         data_receive(-1.0);
     }
+    real_load += received_load;
+    received_load = 0.0;
+    total_load_running -= real_load;
+    convergence_check();
     comm.data_flush(true);
 }
 
+void process::convergence_check()
+{
+    double load_diff = std::fabs(real_load - total_load_average);
+    bool converged = load_diff <= load_diff_threshold;
+
+    if (convergence >= 0.0) {
+        if (!converged) {
+            XBT_VERB("current load has diverged: %g (%.4g%%)",
+                     real_load, 100.0 * load_diff / total_load_average);
+            convergence = -1.0;
+        }
+    } else {
+        if (converged) {
+            XBT_VERB("current load has converged: %g (%.4g%%)",
+                     real_load,  100.0 * load_diff / total_load_average);
+            convergence = MSG_get_clock();
+        }
+    }
+}
+
 bool process::still_running()
 {
     static bool last_status = true;
@@ -300,26 +380,37 @@ void process::ctrl_send(neighbor& nb)
     }
 }
 
+double process::compute_load_to_send(double desired)
+{
+    if (opt::integer_transfer)
+        desired = std::floor(desired);
+    return desired >= opt::min_transfer_amount ? desired : 0.0;
+}
+
 void process::data_send(neighbor& nb)
 {
     double load_to_send;
-    if (opt::bookkeeping) {
-        load_to_send = std::min(real_load, nb.get_debt());
-        if (load_to_send >= opt::min_transfer_amount) {
+    if (opt::bookkeeping) {     // bookkeeping
+        double excess_load;     // load amount we are able to send
+        if (opt::egocentric)
+            excess_load = std::max(0.0, real_load - expected_load);
+        else
+            excess_load = real_load;
+
+        double balance = nb.get_debt() - nb.get_credit();
+        load_to_send = std::min(excess_load,
+                                std::max(0.0, balance));
+
+        // adjust load to send (rounding, truncation, etc.)
+        load_to_send = compute_load_to_send(load_to_send);
+        if (load_to_send > 0.0)
             nb.set_debt(nb.get_debt() - load_to_send);
-            real_load -= load_to_send;
-        } else {
-            load_to_send = 0.0;
-        }
-    } else {
-        load_to_send = nb.get_to_send();
-        if (load_to_send >= opt::min_transfer_amount) {
-            nb.set_to_send(0.0);
-            real_load -= load_to_send;
-        } else {
-            load_to_send = 0.0;
-        }
+    } else {                    // !bookkeeping
+        load_to_send = compute_load_to_send(nb.get_to_send());
+        if (load_to_send > 0.0)
+            nb.set_to_send(nb.get_to_send() - load_to_send);
     }
+    real_load -= load_to_send;
     while (load_to_send > 0.0) {
         double amount;
         if (opt::max_transfer_amount)
@@ -377,14 +468,18 @@ void process::handle_message(message* msg, m_host_t from)
     case message::CTRL: {
         neighbor* n = rev_neigh[from];
         n->set_load(msg->get_amount() + n->get_to_send());
-        expected_load += msg->get_credit(); // may be 0.0 if !opt::bookkeeping
+        if (opt::bookkeeping) {
+            double credit = msg->get_credit();
+            expected_load += credit;
+            n->set_credit(n->get_credit() + credit);
+        }
         break;
     }
     case message::DATA: {
+        neighbor* n = rev_neigh[from];
         double ld = msg->get_amount();
-        real_load += ld;
-        if (finalizing)
-            total_load_running -= ld;
+        received_load += ld;
+        n->set_credit(n->get_credit() - ld);
         break;
     }
     case message::CTRL_CLOSE: