Gather NUPS of all GPUs and print to console

src/gpu/VirtualFluids_GPU/Communication/Communicator.cpp

@@ -205,5 +205,17 @@ int Communicator::mapCudaDevice(const int &rank, const int &size, const std::vec
     return device;
 }
 
+std::vector<double> Communicator::gatherNUPS(double processNups)
+{ 
+    double *buffer_send = &processNups;
+    double *buffer_recv = buffer_recv = (double *)malloc(sizeof(double) * this->numprocs);
+
+    MPI_Gather(buffer_send, 1, MPI_DOUBLE, buffer_recv, 1, MPI_DOUBLE, 0, commGPU);
+
+    if (this->PID == 0)
+        return std::vector<double>(buffer_recv, buffer_recv + this->numprocs);
+    return std::vector<double>(); 
+}
+
 } // namespace GPU
 } // namespace VF

src/gpu/VirtualFluids_GPU/Communication/Communicator.h

@@ -60,6 +60,8 @@ public:
     void stopTimer();
     double getTime();
     int mapCudaDevice(const int &rank, const int &size, const std::vector<unsigned int> &devices, const int &maxdev);
+    std::vector<double> gatherNUPS(double processNups);
+
 protected:
 private:
      static Communicator* instanz;

src/gpu/VirtualFluids_GPU/LBM/Simulation.cpp

@@ -988,6 +988,21 @@ void Simulation::run()
     output << "Nups in Mio: " << fnups << "\n";
     output << "Durchsatz in GB/sec: " << durchsatz << "\n";
 	//////////////////////////////////////////////////////////////////////////
+	
+	//////////////////////////////////////////////////////////////////////////
+    // When using multiple GPUs, get Nups of all processes
+	if (para->getMaxDev() > 1) {
+        std::vector<double> nups = comm->gatherNUPS(fnups);
+        if (comm->getPID() == 0) {
+			double sum = 0;
+            for (uint pid = 0; pid < nups.size(); pid++) {
+                output << "Process " << pid << ": Nups in Mio: " << nups[pid] << "\n";
+                sum += nups[pid];
+			}
+            output << "Sum of all processes: Nups in Mio: " << sum << "\n";
+		}
+	}
+    //////////////////////////////////////////////////////////////////////////
 
 	////////////////////////////////////////////////////////////////////////////////
 	//printDragLift(para);