Sto tentando di allocare memoria del dispositivo, copiare su di esso, eseguire i calcoli sulla GPU, copiare i risultati indietro e quindi liberare la memoria del dispositivo che ho assegnato. Volevo essere sicuro di non andare oltre il limite e volevo vedere se avrei avuto abbastanza memoria nello spazio di memoria condiviso per scaricare alcuni array.Perché CudaFree non sembra liberare memoria?
Quando alloco memoria del dispositivo, non vengono restituiti errori. Quando uso cudaMemGetInfo
per verificare la quantità di memoria allocata, sembra che uno cudaMalloc
non abbia allocato memoria. Anche quando provo a liberare la memoria, sembra che sia stato liberato solo un puntatore.
Sto usando l'interfaccia MATLAB Mexfunction
per impostare la memoria della GPU e avviare il kernel. A questo punto, non sto nemmeno chiamando nel kernel e sto solo ritornando indietro una matrice unitaria per i risultati.
cudaError_t cudaErr;
size_t freeMem = 0;
size_t totalMem = 0;
size_t allocMem = 0;
cudaMemGetInfo(&freeMem, &totalMem);
mexPrintf("Memory avaliable: Free: %lu, Total: %lu\n",freeMem, totalMem);
/* Pointers for the device memory */
double *devicePulseDelay, *deviceTarDistance, *deviceScattDistance, *deviceScatterers;
double *deviceReceivedReal, *deviceReceivedImag;
/* Allocate memory on the device for the arrays. */
mexPrintf("Allocating memory.\n");
cudaErr = cudaMalloc((void **) &devicePulseDelay, sizeof(double)*512);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not allocate memory to devicePulseDelay\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("devicePulseDelay: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMalloc((void **) &deviceTarDistance, sizeof(double)*512);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not allocate memory to deviceTarDistance\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceTarDistance: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMalloc((void **) &deviceScattDistance, sizeof(double)*999*512);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not allocate memory to deviceScattDistance\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceScattDistance: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMalloc((void **) &deviceScatterers, sizeof(double)*999);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not allocate memory to deviceScatterers\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceScatterers: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMalloc((void **) &deviceReceivedReal, sizeof(double)*999*512);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not allocate memory to deviceReceivedReal\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceReceivedReal: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMalloc((void **) &deviceReceivedImag, sizeof(double)*999*512);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not allocate memory to deviceReceivedImag\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceReceivedImag: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n", allocMem, totalMem,(freeMem - allocMem));
/* copy the input arrays across to the device */
mexPrintf("\nCopying memory.\n");
cudaErr = cudaMemcpy(devicePulseDelay, pulseDelay, sizeof(double)*512,cudaMemcpyHostToDevice);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not copy to devicePulseDelay\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("devicePulseDelay: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMemcpy(deviceTarDistance, tarDistance, sizeof(double)*512,cudaMemcpyHostToDevice);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not copy to deviceTarDistance\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceTarDistance: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMemcpy(deviceScattDistance, scattDistance, sizeof(double)*999*512,cudaMemcpyHostToDevice);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not copy to deviceScattDistance\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceScattDistance: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMemcpy(deviceScatterers, scatterers, sizeof(double)*999,cudaMemcpyHostToDevice);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not copy to deviceScatterers\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceScatterers: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
/* call the kernel */
// launchKernel<<<1,512>>>(........);
/* retireve the output */
cudaErr = cudaMemcpy(receivedReal, deviceReceivedReal, sizeof(double)*512*512,cudaMemcpyDeviceToHost);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not copy to receivedReal\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("receivedReal: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
cudaErr = cudaMemcpy(receivedImag, deviceReceivedImag, sizeof(double)*512*512,cudaMemcpyDeviceToHost);
if (cudaErr != cudaSuccess)
{
mexPrintf("could not copy to receivedImag\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("receivedImag: Memory avaliable: Free: %lu, Total: %lu, Consumed: %lu\n",allocMem, totalMem,(freeMem - allocMem));
/* free the memory. */
mexPrintf("\nFree'ing memory.\n");
cudaMemGetInfo(&freeMem, &totalMem);
mexPrintf("Before freeing: Free %lu, Total: %lu\n", freeMem, totalMem);
cudaErr = cudaFree(devicePulseDelay);
if (cudaErr != cudaSuccess)
{
mexPrintf("could free devicePulseDelay\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("devicePulseDelay: Memory avaliable: Free: %lu, Total: %lu, Free'd: %lu\n",allocMem, totalMem,(allocMem - freeMem));
cudaErr = cudaFree(deviceTarDistance);
if (cudaErr != cudaSuccess)
{
mexPrintf("could free deviceTarDistance\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceTarDistance: Memory avaliable: Free: %lu, Total: %lu, Free'd: %lu\n",allocMem, totalMem,(allocMem - freeMem));
cudaErr = cudaFree(deviceScattDistance);
if (cudaErr != cudaSuccess)
{
mexPrintf("could free deviceScattDistance\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceScattDistance: Memory avaliable: Free: %lu, Total: %lu, Free'd: %lu\n",allocMem, totalMem,(allocMem - freeMem));
cudaErr = cudaFree(deviceScatterers);
if (cudaErr != cudaSuccess)
{
mexPrintf("could free deviceScatterers\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceScatterers: Memory avaliable: Free: %lu, Total: %lu, Free'd: %lu\n",allocMem, totalMem,(allocMem - freeMem));
cudaErr = cudaFree(deviceReceivedReal);
if (cudaErr != cudaSuccess)
{
mexPrintf("could free deviceReceivedReal\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceReceivedReal: Memory avaliable: Free: %lu, Total: %lu, Free'd: %lu\n",allocMem, totalMem,(allocMem - freeMem));
cudaErr = cudaFree(deviceReceivedImag);
if (cudaErr != cudaSuccess)
{
mexPrintf("could free deviceReceivedImag\n");
mexPrintf("Error: %s\n",cudaGetErrorString(cudaErr));
}
cudaMemGetInfo(&allocMem, &totalMem);
mexPrintf("deviceReceivedImag: Memory avaliable: Free: %lu, Total: %lu, Free'd: %lu\n",allocMem, totalMem,(allocMem - freeMem));
Ecco l'output di questo:
Memory avaliable: Free: 2523959296, Total: 2818572288 Allocating memory. devicePulseDelay: Memory avaliable: Free: 2522910720, Total: 2818572288, Consumed: 1048576 deviceTarDistance: Memory avaliable: Free: 2522910720, Total: 2818572288, Consumed: 1048576 deviceScattDistance: Memory avaliable: Free: 2518716416, Total: 2818572288, Consumed: 5242880 deviceScatterers: Memory avaliable: Free: 2517667840, Total: 2818572288, Consumed: 6291456 deviceReceivedReal: Memory avaliable: Free: 2515570688, Total: 2818572288, Consumed: 8388608 deviceReceivedImag: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 Copying memory. devicePulseDelay: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 deviceTarDistance: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 deviceScattDistance: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 deviceScatterers: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 receivedReal: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 receivedImag: Memory avaliable: Free: 2513473536, Total: 2818572288, Consumed: 10485760 Free'ing memory. Before freeing: Free 2513473536, Total: 2818572288 devicePulseDelay: Memory avaliable: Free: 2513473536, Total: 2818572288, Free'd: 0 deviceTarDistance: Memory avaliable: Free: 2513473536, Total: 2818572288, Free'd: 0 deviceScattDistance: Memory avaliable: Free: 2513473536, Total: 2818572288, Free'd: 0 deviceScatterers: Memory avaliable: Free: 2514522112, Total: 2818572288, Free'd: 1048576 deviceReceivedReal: Memory avaliable: Free: 2514522112, Total: 2818572288, Free'd: 1048576 deviceReceivedImag: Memory avaliable: Free: 2514522112, Total: 2818572288, Free'd: 1048576
mi sento come se ci fosse qualcosa di ovvio che mi manca. Qualcuno può aiutare a spiegare cosa sta succedendo?
MODIFICA: la piattaforma è Windows 7 con una scheda GPu Tesla C2050.
Su quale piattaforma è in esecuzione questo codice? – talonmies
Provare a azzerare i valori di allocMem e totalMem prima di ogni chiamata a cudaMemGetInfo() e controllare il valore restituito da cudaMemGetInfo(). –
azzerando l'allocMem e il totalMem prima di ogni chiamata a cudaMemGetInfo() non ha fatto alcuna differenza. Anche le chiamate cudaMemGetInfo non hanno restituito alcun errore. Cordiali saluti, la mia piattaforma è Windows 7 su una scheda GPU Tesla C2050. –