opm-simulators/opm/simulators/linalg/gpuistl/detail/gpuThreadUtils.hpp
2024-08-23 11:12:13 +02:00

67 lines
1.8 KiB
C++

/*
Copyright 2024 SINTEF AS
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_GPU_THREAD_UTILS_HPP
#define OPM_GPU_THREAD_UTILS_HPP
#include <cstddef>
#include <cuda.h>
#include <cuda_runtime.h>
#include <opm/simulators/linalg/gpuistl/detail/gpu_safe_call.hpp>
/*
This file provides some logic for handling how to choose the correct thread-block size
*/
namespace Opm::gpuistl::detail
{
constexpr inline size_t
getThreads([[maybe_unused]] size_t numberOfRows)
{
return 1024;
}
inline size_t
getBlocks(size_t numberOfRows)
{
const auto threads = getThreads(numberOfRows);
return (numberOfRows + threads - 1) / threads;
}
// Kernel here is the function object of the cuda kernel
template <class Kernel>
inline int
getCudaRecomendedThreadBlockSize(Kernel k, int suggestedThrBlockSize = -1)
{
if (suggestedThrBlockSize != -1) {
return suggestedThrBlockSize;
}
int blockSize;
int tmpGridSize;
OPM_GPU_SAFE_CALL(cudaOccupancyMaxPotentialBlockSize(&tmpGridSize, &blockSize, k, 0, 0));
return blockSize;
}
inline int
getNumberOfBlocks(int wantedThreads, int threadBlockSize)
{
return (wantedThreads + threadBlockSize - 1) / threadBlockSize;
}
} // namespace Opm::gpuistl::detail
#endif