From 805029acc414ec084affd6d6f2790e1f1fa20017 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Date: Sun, 20 Feb 2011 21:08:51 +0100
Subject: [PATCH] Add options to control min./max. data transfer amount.

---
 options.cpp | 24 +++++++++++++++++++++++-
 options.h   |  2 ++
 process.cpp | 30 +++++++++++++++++++-----------
 3 files changed, 44 insertions(+), 12 deletions(-)

diff --git a/options.cpp b/options.cpp
index 189bed2..9f7ea5c 100644
--- a/options.cpp
+++ b/options.cpp
@@ -48,6 +48,8 @@ namespace opt {
     std::string loba_algo("simple");
     bool bookkeeping = false;
     double min_lb_iter_duration = 1.0;          // fixme: find better defaults
+    double min_transfer_amount = 0.0;
+    double max_transfer_amount = 0.0;
 
     // Application parameters
     cost_func comp_cost("1e9, 0");              // fixme: find better defaults
@@ -201,7 +203,7 @@ bool opt::parse_args(int* argc, char* argv[])
     int c;
     opterr = 0;
     while ((c = getopt(*argc, argv,
-                       "a:bc:C:d:D:ehi:I:l:L:N:s:S:t:T:vV")) != -1) {
+                       "a:bc:C:d:D:ehi:I:l:L:m:M:N:s:S:t:T:vV")) != -1) {
         switch (c) {
         case 'a':
             opt::loba_algo = optarg;
@@ -255,6 +257,12 @@ bool opt::parse_args(int* argc, char* argv[])
         case 'L':
             PARSE_ARG(opt::auto_depl::load);
             break;
+        case 'm':
+            PARSE_ARG(opt::min_transfer_amount);
+            break;
+        case 'M':
+            PARSE_ARG(opt::max_transfer_amount);
+            break;
         case 'N':
             PARSE_ARG(opt::auto_depl::nhosts);
             break;
@@ -308,6 +316,12 @@ bool opt::parse_args(int* argc, char* argv[])
         result = false;
     }
 
+    if (opt::max_transfer_amount &&
+        opt::max_transfer_amount < opt::min_transfer_amount) {
+        XBT_ERROR("max. data transfer amount < min. data transfer amount");
+        result = false;
+    }
+
     return result;
 }
 
@@ -337,6 +351,8 @@ void opt::print()
           min_lb_iter_duration);
     DESCR("computation cost factors", "[%s]", comp_cost.to_string().c_str());
     DESCR("communication cost factors", "[%s]", comm_cost.to_string().c_str());
+    DESCR("minimum data transfer amount", "%g", min_transfer_amount);
+    DESCR("maximum data transfer amount", "%g", max_transfer_amount);
     DESCR("minimum duration between comp. iterations", "%g",
           min_comp_iter_duration);
     DESCR("computations start after lb. iter", "%u", comp_iter_delay);
@@ -418,6 +434,12 @@ void opt::usage()
     std::clog << o("-C [aN,...]a0")
               << "polynomial factors for communication cost"
               << " [" << opt::comm_cost.to_string() << "]\n";
+    std::clog << o("-m value")
+              << "minimum data transfer amount"
+              << " [" << opt::min_transfer_amount << "]\n";
+    std::clog << o("-M value")
+              << "maximum data transfer amount (0 for no limit)"
+              << " [" << opt::max_transfer_amount << "]\n";
     std::clog << o("-S value")
               << "minimum duration between comp. iterations"
               << " [" << opt::min_comp_iter_duration << "]\n";
diff --git a/options.h b/options.h
index 1032a63..b3e3081 100644
--- a/options.h
+++ b/options.h
@@ -38,6 +38,8 @@ namespace opt {
     // Load balancing algorithm
     extern std::string loba_algo;
     extern bool bookkeeping;
+    extern double min_transfer_amount;
+    extern double max_transfer_amount;
     extern double min_lb_iter_duration;
 
     // Application parameters
diff --git a/process.cpp b/process.cpp
index 2b1b369..33a993e 100644
--- a/process.cpp
+++ b/process.cpp
@@ -302,23 +302,31 @@ void process::data_send(neighbor& nb)
 {
     double load_to_send;
     if (opt::bookkeeping) {
-        if (real_load <= nb.get_debt()) {
-            load_to_send = real_load;
+        load_to_send = std::min(real_load, nb.get_debt());
+        if (load_to_send >= opt::min_transfer_amount) {
             nb.set_debt(nb.get_debt() - load_to_send);
-            real_load = 0.0;
-        } else {
-            load_to_send = nb.get_debt();
-            nb.set_debt(0.0);
             real_load -= load_to_send;
+        } else {
+            load_to_send = 0.0;
         }
     } else {
         load_to_send = nb.get_to_send();
-        nb.set_to_send(0.0);
-        real_load -= load_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;
+        }
+    }
+    while (load_to_send > 0.0) {
+        double amount;
+        if (opt::max_transfer_amount)
+            amount = std::min(load_to_send, opt::max_transfer_amount);
+        else
+            amount = load_to_send;
+        comm.data_send(nb.get_data_mbox(), new message(message::LOAD, amount));
+        load_to_send -= amount;
     }
-    if (load_to_send > 0.0)
-        comm.data_send(nb.get_data_mbox(),
-                       new message(message::LOAD, load_to_send));
 }
 
 void process::ctrl_close(neighbor& nb)
-- 
2.39.5