diff options
| -rw-r--r-- | openmp/libomptarget/plugins/cuda/src/rtl.cpp | 69 |
1 files changed, 37 insertions, 32 deletions
diff --git a/openmp/libomptarget/plugins/cuda/src/rtl.cpp b/openmp/libomptarget/plugins/cuda/src/rtl.cpp index 872e7f02aed..d265a87b83d 100644 --- a/openmp/libomptarget/plugins/cuda/src/rtl.cpp +++ b/openmp/libomptarget/plugins/cuda/src/rtl.cpp @@ -285,43 +285,48 @@ int32_t __tgt_rtl_init_device(int32_t device_id) { return OFFLOAD_FAIL; } - // scan properties to determine number of threads/block and blocks/grid. - CUdevprop Properties; - err = cuDeviceGetProperties(&Properties, cuDevice); + // Query attributes to determine number of threads/block and blocks/grid. + int maxGridDimX; + err = cuDeviceGetAttribute(&maxGridDimX, CU_DEVICE_ATTRIBUTE_MAX_GRID_DIM_X, + cuDevice); if (err != CUDA_SUCCESS) { - DP("Error getting device Properties, use defaults\n"); + DP("Error getting max grid dimension, use default\n"); DeviceInfo.BlocksPerGrid[device_id] = RTLDeviceInfoTy::DefaultNumTeams; - DeviceInfo.ThreadsPerBlock[device_id] = RTLDeviceInfoTy::DefaultNumThreads; - DeviceInfo.WarpSize[device_id] = 32; + } else if (maxGridDimX <= RTLDeviceInfoTy::HardTeamLimit) { + DeviceInfo.BlocksPerGrid[device_id] = maxGridDimX; + DP("Using %d CUDA blocks per grid\n", maxGridDimX); } else { - // Get blocks per grid - if (Properties.maxGridSize[0] <= RTLDeviceInfoTy::HardTeamLimit) { - DeviceInfo.BlocksPerGrid[device_id] = Properties.maxGridSize[0]; - DP("Using %d CUDA blocks per grid\n", Properties.maxGridSize[0]); - } else { - DeviceInfo.BlocksPerGrid[device_id] = RTLDeviceInfoTy::HardTeamLimit; - DP("Max CUDA blocks per grid %d exceeds the hard team limit %d, capping " - "at the hard limit\n", Properties.maxGridSize[0], - RTLDeviceInfoTy::HardTeamLimit); - } + DeviceInfo.BlocksPerGrid[device_id] = RTLDeviceInfoTy::HardTeamLimit; + DP("Max CUDA blocks per grid %d exceeds the hard team limit %d, capping " + "at the hard limit\n", + maxGridDimX, RTLDeviceInfoTy::HardTeamLimit); + } - // Get threads per block, exploit threads only along x axis - if (Properties.maxThreadsDim[0] <= RTLDeviceInfoTy::HardThreadLimit) { - DeviceInfo.ThreadsPerBlock[device_id] = Properties.maxThreadsDim[0]; - DP("Using %d CUDA threads per block\n", Properties.maxThreadsDim[0]); - if (Properties.maxThreadsDim[0] < Properties.maxThreadsPerBlock) { - DP("(fewer than max per block along all xyz dims %d)\n", - Properties.maxThreadsPerBlock); - } - } else { - DeviceInfo.ThreadsPerBlock[device_id] = RTLDeviceInfoTy::HardThreadLimit; - DP("Max CUDA threads per block %d exceeds the hard thread limit %d, " - "capping at the hard limit\n", Properties.maxThreadsDim[0], - RTLDeviceInfoTy::HardThreadLimit); - } + // We are only exploiting threads along the x axis. + int maxBlockDimX; + err = cuDeviceGetAttribute(&maxBlockDimX, CU_DEVICE_ATTRIBUTE_MAX_BLOCK_DIM_X, + cuDevice); + if (err != CUDA_SUCCESS) { + DP("Error getting max block dimension, use default\n"); + DeviceInfo.ThreadsPerBlock[device_id] = RTLDeviceInfoTy::DefaultNumThreads; + } else if (maxBlockDimX <= RTLDeviceInfoTy::HardThreadLimit) { + DeviceInfo.ThreadsPerBlock[device_id] = maxBlockDimX; + DP("Using %d CUDA threads per block\n", maxBlockDimX); + } else { + DeviceInfo.ThreadsPerBlock[device_id] = RTLDeviceInfoTy::HardThreadLimit; + DP("Max CUDA threads per block %d exceeds the hard thread limit %d, capping" + "at the hard limit\n", + maxBlockDimX, RTLDeviceInfoTy::HardThreadLimit); + } - // According to the documentation, SIMDWidth is "Warp size in threads". - DeviceInfo.WarpSize[device_id] = Properties.SIMDWidth; + int warpSize; + err = + cuDeviceGetAttribute(&warpSize, CU_DEVICE_ATTRIBUTE_WARP_SIZE, cuDevice); + if (err != CUDA_SUCCESS) { + DP("Error getting warp size, assume default\n"); + DeviceInfo.WarpSize[device_id] = 32; + } else { + DeviceInfo.WarpSize[device_id] = warpSize; } // Adjust teams to the env variables |
