CUDA device manager. More...

Collaboration diagram for CUDADeviceManager:

Public Member Functions
	CUDADeviceManager (int &default_device_num, int &num_devices, int local_rank, int local_size)

Private Attributes
int	cuda_default_device_num

int	cuda_device_count

Detailed Description

CUDA device manager.

Definition at line 22 of file CUDADeviceManager.h.

Constructor & Destructor Documentation

◆ CUDADeviceManager()

CUDADeviceManager	(	int &	default_device_num,
		int &	num_devices,
		int	local_rank,
		int	local_size
	)

Definition at line 22 of file CUDADeviceManager.cpp.

References qmcplusplus::app_warning(), CUDADeviceManager::cuda_default_device_num, CUDADeviceManager::cuda_device_count, qmcplusplus::cudaErrorCheck(), cudaFree, cudaGetDeviceCount, cudaSetDevice, and qmcplusplus::determineDefaultDeviceNum().

     : cuda_default_device_num(-1), cuda_device_count(0)
 {
   cudaErrorCheck(cudaGetDeviceCount(&cuda_device_count), "cudaGetDeviceCount failed!");
   if (num_devices == 0)
     num_devices = cuda_device_count;
   else if (num_devices != cuda_device_count)
     throw std::runtime_error("Inconsistent number of CUDA devices with the previous record!");
   if (cuda_device_count > local_size)
     app_warning() << "More CUDA devices than the number of MPI ranks. "
                   << "Some devices will be left idle.\n"
                   << "There is potential performance issue with the GPU affinity. "
                   << "Use CUDA_VISIBLE_DEVICE or MPI launcher to expose desired devices.\n";
   if (num_devices > 0)
   {
     cuda_default_device_num = determineDefaultDeviceNum(cuda_device_count, local_rank, local_size);
     if (default_device_num < 0)
       default_device_num = cuda_default_device_num;
     else if (default_device_num != cuda_default_device_num)
       throw std::runtime_error("Inconsistent assigned CUDA devices with the previous record!");
 
 #pragma omp parallel
     {
       cudaErrorCheck(cudaSetDevice(cuda_default_device_num), "cudaSetDevice failed!");
       cudaErrorCheck(cudaFree(0), "cudaFree failed!");
     }
   }
 }

Member Data Documentation

◆ cuda_default_device_num

int cuda_default_device_num

private

Definition at line 24 of file CUDADeviceManager.h.

Referenced by CUDADeviceManager::CUDADeviceManager().

◆ cuda_device_count

int cuda_device_count

private

Definition at line 25 of file CUDADeviceManager.h.