mem-garnet: Added packet distribution stats

Trace data and control traffic between all source-destination pairs.
This is for identifying packet distribution and bottleneck of the
interconnect network.

Change-Id: Iffc9c16fd1e02ab8f7c5382cec822bf57a43a057
JIRA: https://gem5.atlassian.net/browse/GEM5-861
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40275
Reviewed-by: Srikant Bharadwaj <srikant.bharadwaj@amd.com>
Maintainer: Srikant Bharadwaj <srikant.bharadwaj@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/mem/ruby/network/garnet/GarnetNetwork.cc

@@ -500,6 +500,25 @@ GarnetNetwork::regStats()
         .name(name() + ".avg_vc_load")
         .flags(Stats::pdf | Stats::total | Stats::nozero | Stats::oneline)
         ;
+
+    // Traffic distribution
+    for (int source = 0; source < m_routers.size(); ++source) {
+        m_data_traffic_distribution.push_back(std::vector<Stats::Scalar *>());
+        m_ctrl_traffic_distribution.push_back(std::vector<Stats::Scalar *>());
+
+        for (int dest = 0; dest < m_routers.size(); ++dest) {
+            Stats::Scalar *data_packets = new Stats::Scalar();
+            Stats::Scalar *ctrl_packets = new Stats::Scalar();
+
+            data_packets->name(name() + ".data_traffic_distribution." + "n" +
+                    std::to_string(source) + "." + "n" + std::to_string(dest));
+            m_data_traffic_distribution[source].push_back(data_packets);
+
+            ctrl_packets->name(name() + ".ctrl_traffic_distribution." + "n" +
+                    std::to_string(source) + "." + "n" + std::to_string(dest));
+            m_ctrl_traffic_distribution[source].push_back(ctrl_packets);
+        }
+    }
 }
 
 void
@@ -554,6 +573,19 @@ GarnetNetwork::print(std::ostream& out) const
     out << "[GarnetNetwork]";
 }
 
+void
+GarnetNetwork::update_traffic_distribution(RouteInfo route)
+{
+    int src_node = route.src_router;
+    int dest_node = route.dest_router;
+    int vnet = route.vnet;
+
+    if (m_vnet_type[vnet] == DATA_VNET_)
+        (*m_data_traffic_distribution[src_node][dest_node])++;
+    else
+        (*m_ctrl_traffic_distribution[src_node][dest_node])++;
+}
+
 uint32_t
 GarnetNetwork::functionalWrite(Packet *pkt)
 {

src/mem/ruby/network/garnet/GarnetNetwork.hh

@@ -142,6 +142,8 @@ class GarnetNetwork : public Network
         m_total_hops += hops;
     }
 
+    void update_traffic_distribution(RouteInfo route);
+
   protected:
     // Configuration
     int m_num_rows;
@@ -185,6 +187,9 @@ class GarnetNetwork : public Network
     Stats::Scalar  m_total_hops;
     Stats::Formula m_avg_hops;
 
+    std::vector<std::vector<Stats::Scalar *>> m_data_traffic_distribution;
+    std::vector<std::vector<Stats::Scalar *>> m_ctrl_traffic_distribution;
+
   private:
     GarnetNetwork(const GarnetNetwork& obj);
     GarnetNetwork& operator=(const GarnetNetwork& obj);

src/mem/ruby/network/garnet/NetworkInterface.cc

@@ -426,6 +426,7 @@ NetworkInterface::flitisizeMessage(MsgPtr msg_ptr, int vnet)
         route.hops_traversed = -1;
 
         m_net_ptr->increment_injected_packets(vnet);
+        m_net_ptr->update_traffic_distribution(route);
         for (int i = 0; i < num_flits; i++) {
             m_net_ptr->increment_injected_flits(vnet);
             flit *fl = new flit(i, vc, vnet, route, num_flits, new_msg_ptr,