Merge pull request #2209 from Tongdongq/master

Added cusparseSolver, needs GPU to be used
This commit is contained in:
Markus Blatt 2019-12-20 11:37:27 +01:00 committed by GitHub
commit b9062396be
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GPG Key ID: 4AEE18F83AFDEB23
11 changed files with 1122 additions and 0 deletions

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@ -12,10 +12,20 @@
###########################################################################
# Mandatory call to project
project(opm-simulators C CXX)
cmake_minimum_required (VERSION 2.8)
find_package(CUDA)
if(CUDA_FOUND)
include_directories(${CUDA_INCLUDE_DIRS})
enable_language(CUDA)
set(HAVE_CUDA 1)
endif()
option(SIBLING_SEARCH "Search for other modules in sibling directories?" ON)
set( USE_OPENMP_DEFAULT OFF ) # Use of OpenMP is considered experimental
option(BUILD_FLOW "Build the production oriented flow simulator?" ON)
@ -286,3 +296,10 @@ endif()
if (OPM_ENABLE_PYTHON)
add_subdirectory(python)
endif()
# must link libraries after target 'flow' has been defined
if(CUDA_FOUND)
target_link_libraries( opmsimulators ${CUDA_cublas_LIBRARY} )
target_link_libraries( opmsimulators ${CUDA_cusparse_LIBRARY} )
endif()

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@ -29,6 +29,7 @@ list (APPEND MAIN_SOURCE_FILES
opm/simulators/flow/MissingFeatures.cpp
opm/simulators/linalg/ExtractParallelGridInformationToISTL.cpp
opm/simulators/linalg/setupPropertyTree.cpp
opm/simulators/linalg/bda/BdaBridge.cpp
opm/simulators/timestepping/TimeStepControl.cpp
opm/simulators/timestepping/AdaptiveSimulatorTimer.cpp
opm/simulators/timestepping/SimulatorTimer.cpp
@ -41,6 +42,10 @@ list (APPEND MAIN_SOURCE_FILES
opm/simulators/wells/VFPInjProperties.cpp
)
if(CUDA_FOUND)
list (APPEND MAIN_SOURCE_FILES opm/simulators/linalg/bda/cusparseSolverBackend.cu)
endif()
# originally generated with the command:
# find tests -name '*.cpp' -a ! -wholename '*/not-unit/*' -printf '\t%p\n' | sort
list (APPEND TEST_SOURCE_FILES
@ -129,6 +134,10 @@ list (APPEND PUBLIC_HEADER_FILES
opm/simulators/aquifers/AquiferFetkovich.hpp
opm/simulators/aquifers/BlackoilAquiferModel.hpp
opm/simulators/aquifers/BlackoilAquiferModel_impl.hpp
opm/simulators/linalg/bda/BdaBridge.hpp
opm/simulators/linalg/bda/BdaResult.hpp
opm/simulators/linalg/bda/cuda_header.hpp
opm/simulators/linalg/bda/cusparseSolverBackend.hpp
opm/simulators/linalg/BlackoilAmg.hpp
opm/simulators/linalg/BlackoilAmgCpr.hpp
opm/simulators/linalg/amgcpr.hh

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@ -5,6 +5,7 @@ set (opm-simulators_CONFIG_VAR
HAVE_EWOMS
HAVE_MPI
HAVE_PETSC
HAVE_CUDA
HAVE_SUITESPARSE_UMFPACK_H
HAVE_DUNE_ISTL
DUNE_ISTL_VERSION_MAJOR

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@ -67,6 +67,7 @@ NEW_PROP_TAG(CprMaxEllIter);
NEW_PROP_TAG(CprEllSolvetype);
NEW_PROP_TAG(CprReuseSetup);
NEW_PROP_TAG(LinearSolverConfigurationJsonFile);
NEW_PROP_TAG(UseGpu);
SET_SCALAR_PROP(FlowIstlSolverParams, LinearSolverReduction, 1e-2);
SET_SCALAR_PROP(FlowIstlSolverParams, IluRelaxation, 0.9);
@ -92,6 +93,7 @@ SET_INT_PROP(FlowIstlSolverParams, CprMaxEllIter, 20);
SET_INT_PROP(FlowIstlSolverParams, CprEllSolvetype, 0);
SET_INT_PROP(FlowIstlSolverParams, CprReuseSetup, 0);
SET_STRING_PROP(FlowIstlSolverParams, LinearSolverConfigurationJsonFile, "none");
SET_BOOL_PROP(FlowIstlSolverParams, UseGpu, false);
@ -163,6 +165,7 @@ namespace Opm
std::string system_strategy_;
bool scale_linear_system_;
std::string linear_solver_configuration_json_file_;
bool use_gpu_;
template <class TypeTag>
void init()
@ -190,6 +193,7 @@ namespace Opm
cpr_ell_solvetype_ = EWOMS_GET_PARAM(TypeTag, int, CprEllSolvetype);
cpr_reuse_setup_ = EWOMS_GET_PARAM(TypeTag, int, CprReuseSetup);
linear_solver_configuration_json_file_ = EWOMS_GET_PARAM(TypeTag, std::string, LinearSolverConfigurationJsonFile);
use_gpu_ = EWOMS_GET_PARAM(TypeTag, bool, UseGpu);
}
template <class TypeTag>
@ -217,6 +221,7 @@ namespace Opm
EWOMS_REGISTER_PARAM(TypeTag, int, CprEllSolvetype, "Solver type of elliptic pressure solve (0: bicgstab, 1: cg, 2: only amg preconditioner)");
EWOMS_REGISTER_PARAM(TypeTag, int, CprReuseSetup, "Reuse Amg Setup");
EWOMS_REGISTER_PARAM(TypeTag, std::string, LinearSolverConfigurationJsonFile, "Filename of JSON configuration for flexible linear solver system.");
EWOMS_REGISTER_PARAM(TypeTag, bool, UseGpu, "Use GPU cusparseSolver as the linear solver");
}
FlowLinearSolverParameters() { reset(); }
@ -238,6 +243,7 @@ namespace Opm
ilu_milu_ = MILU_VARIANT::ILU;
ilu_redblack_ = false;
ilu_reorder_sphere_ = true;
use_gpu_ = false;
}
};

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@ -45,6 +45,8 @@
#include <opm/common/utility/platform_dependent/reenable_warnings.h>
#include <opm/simulators/linalg/bda/BdaBridge.hpp>
BEGIN_PROPERTIES
NEW_TYPE_TAG(FlowIstlSolver, INHERITS_FROM(FlowIstlSolverParams));
@ -222,6 +224,10 @@ protected:
enum { pressureVarIndex = Indices::pressureSwitchIdx };
static const int numEq = Indices::numEq;
#if HAVE_CUDA
std::unique_ptr<BdaBridge> bdaBridge;
#endif
public:
typedef Dune::AssembledLinearOperator< Matrix, Vector, Vector > AssembledLinearOperatorType;
@ -239,6 +245,22 @@ protected:
converged_(false)
{
parameters_.template init<TypeTag>();
#if HAVE_CUDA
const bool use_gpu = EWOMS_GET_PARAM(TypeTag, bool, UseGpu);
const int maxit = EWOMS_GET_PARAM(TypeTag, int, LinearSolverMaxIter);
const double tolerance = EWOMS_GET_PARAM(TypeTag, double, LinearSolverReduction);
const bool matrix_add_well_contributions = EWOMS_GET_PARAM(TypeTag, bool, MatrixAddWellContributions);
const int linear_solver_verbosity = parameters_.linear_solver_verbosity_;
if (use_gpu && !matrix_add_well_contributions) {
OPM_THROW(std::logic_error,"Error cannot use GPU solver if command line parameter --matrix-add-well-contributions is false, because the GPU solver performs a standard bicgstab");
}
bdaBridge.reset(new BdaBridge(use_gpu, linear_solver_verbosity, maxit, tolerance));
#else
const bool use_gpu = EWOMS_GET_PARAM(TypeTag, bool, UseGpu);
if (use_gpu) {
OPM_THROW(std::logic_error,"Error cannot use GPU solver since CUDA was not found during compilation");
}
#endif
extractParallelGridInformationToISTL(simulator_.vanguard().grid(), parallelInformation_);
const auto& gridForConn = simulator_.vanguard().grid();
const auto wellsForConn = simulator_.vanguard().schedule().getWellsatEnd();
@ -436,11 +458,30 @@ protected:
else
#endif
{
// tries to solve linear system
// solve_system() does nothing if Dune is selected
#if HAVE_CUDA
bdaBridge->solve_system(matrix_.get(), istlb, result);
if (result.converged) {
// get result vector x from non-Dune backend, iff solve was successful
bdaBridge->get_result(x);
} else {
// CPU fallback, or default case for Dune
const bool use_gpu = EWOMS_GET_PARAM(TypeTag, bool, UseGpu);
if (use_gpu) {
OpmLog::warning("cusparseSolver did not converge, now trying Dune to solve current linear system...");
}
auto precond = constructPrecond(linearOperator, parallelInformation_arg);
solve(linearOperator, x, istlb, *sp, *precond, result);
} // end Dune call
#else
// Construct preconditioner.
auto precond = constructPrecond(linearOperator, parallelInformation_arg);
// Solve.
solve(linearOperator, x, istlb, *sp, *precond, result);
#endif
}
}

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@ -0,0 +1,240 @@
/*
Copyright 2019 Equinor ASA
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/>.
*/
#include <config.h>
#include <memory>
#include <sstream>
#include <opm/common/OpmLog/OpmLog.hpp>
#include <opm/common/ErrorMacros.hpp>
#include <opm/material/common/Unused.hpp>
#include <opm/simulators/linalg/bda/BdaBridge.hpp>
#include <opm/simulators/linalg/bda/BdaResult.hpp>
#define PRINT_TIMERS_BRIDGE 0
typedef Dune::InverseOperatorResult InverseOperatorResult;
namespace Opm
{
BdaBridge::BdaBridge(bool use_gpu_ OPM_UNUSED, int linear_solver_verbosity OPM_UNUSED, int maxit OPM_UNUSED, double tolerance OPM_UNUSED) : use_gpu(use_gpu_) {
#if HAVE_CUDA
if (use_gpu) {
backend.reset(new cusparseSolverBackend(linear_solver_verbosity, maxit, tolerance));
}
#endif
}
#if HAVE_CUDA
template <class BridgeMatrix>
int checkZeroDiagonal(BridgeMatrix& mat) {
static std::vector<typename BridgeMatrix::size_type> diag_indices; // contains offsets of the diagonal nnzs
int numZeros = 0;
const int dim = 3; // might be replaced with mat[0][0].N() or BridgeMatrix::block_type::size()
const double zero_replace = 1e-15;
if (diag_indices.size() == 0) {
int N = mat.N();
diag_indices.reserve(N);
for (typename BridgeMatrix::iterator r = mat.begin(); r != mat.end(); ++r) {
auto diag = r->find(r.index()); // diag is an iterator
assert(diag.index() == r.index());
for (int rr = 0; rr < dim; ++rr) {
auto& val = (*diag)[rr][rr]; // reference to easily change the value
if (val == 0.0) { // could be replaced by '< 1e-30' or similar
val = zero_replace;
++numZeros;
}
}
diag_indices.emplace_back(diag.offset());
}
}else{
for (typename BridgeMatrix::iterator r = mat.begin(); r != mat.end(); ++r) {
typename BridgeMatrix::size_type offset = diag_indices[r.index()];
auto& diag_block = r->getptr()[offset]; // diag_block is a reference to MatrixBlock, located on column r of row r
for (int rr = 0; rr < dim; ++rr) {
auto& val = diag_block[rr][rr];
if (val == 0.0) { // could be replaced by '< 1e-30' or similar
val = zero_replace;
++numZeros;
}
}
}
}
return numZeros;
}
// iterate sparsity pattern from Matrix and put colIndices and rowPointers in arrays
// sparsity pattern should stay the same due to matrix-add-well-contributions
// this could be removed if Dune::BCRSMatrix features an API call that returns colIndices and rowPointers
template <class BridgeMatrix>
void getSparsityPattern(BridgeMatrix& mat, std::vector<int> &h_rows, std::vector<int> &h_cols) {
int sum_nnzs = 0;
// convert colIndices and rowPointers
if (h_rows.size() == 0) {
h_rows.emplace_back(0);
for (typename BridgeMatrix::const_iterator r = mat.begin(); r != mat.end(); ++r) {
int size_row = 0;
for (auto c = r->begin(); c != r->end(); ++c) {
h_cols.emplace_back(c.index());
size_row++;
}
sum_nnzs += size_row;
h_rows.emplace_back(sum_nnzs);
}
// h_rows and h_cols could be changed to 'unsigned int', but cusparse expects 'int'
if (static_cast<unsigned int>(h_rows[mat.N()]) != mat.nonzeroes()) {
OPM_THROW(std::logic_error, "Error size of rows do not sum to number of nonzeroes in BdaBridge::getSparsityPattern()");
}
}
} // end getSparsityPattern()
#endif
template <class BridgeMatrix, class BridgeVector>
void BdaBridge::solve_system(BridgeMatrix *mat OPM_UNUSED, BridgeVector &b OPM_UNUSED, InverseOperatorResult &res OPM_UNUSED)
{
#if HAVE_CUDA
if (use_gpu) {
BdaResult result;
result.converged = false;
static std::vector<int> h_rows;
static std::vector<int> h_cols;
const int dim = (*mat)[0][0].N();
const int N = mat->N()*dim;
const int nnz = (h_rows.empty()) ? mat->nonzeroes()*dim*dim : h_rows.back()*dim*dim;
if (dim != 3) {
OpmLog::warning("cusparseSolver only accepts blocksize = 3 at this time, will use Dune for the remainder of the program");
use_gpu = false;
}
if (h_rows.capacity() == 0) {
h_rows.reserve(N+1);
h_cols.reserve(nnz);
#if PRINT_TIMERS_BRIDGE
Dune::Timer t;
#endif
getSparsityPattern(*mat, h_rows, h_cols);
#if PRINT_TIMERS_BRIDGE
std::ostringstream out;
out << "getSparsityPattern() took: " << t.stop() << " s";
OpmLog::info(out.str());
#endif
}
#if PRINT_TIMERS_BRIDGE
Dune::Timer t_zeros;
int numZeros = checkZeroDiagonal(*mat);
std::ostringstream out;
out << "Checking zeros took: " << t_zeros.stop() << " s, found " << numZeros << " zeros";
OpmLog::info(out.str());
#else
checkZeroDiagonal(*mat);
#endif
/////////////////////////
// actually solve
typedef cusparseSolverBackend::cusparseSolverStatus cusparseSolverStatus;
// assume that underlying data (nonzeroes) from mat (Dune::BCRSMatrix) are contiguous, if this is not the case, cusparseSolver is expected to perform undefined behaviour
cusparseSolverStatus status = backend->solve_system(N, nnz, dim, static_cast<double*>(&(((*mat)[0][0][0][0]))), h_rows.data(), h_cols.data(), static_cast<double*>(&(b[0][0])), result);
switch(status) {
case cusparseSolverStatus::CUSPARSE_SOLVER_SUCCESS:
//OpmLog::info("cusparseSolver converged");
break;
case cusparseSolverStatus::CUSPARSE_SOLVER_ANALYSIS_FAILED:
OpmLog::warning("cusparseSolver could not analyse level information of matrix, perhaps there is still a 0.0 on the diagonal of a block on the diagonal");
break;
case cusparseSolverStatus::CUSPARSE_SOLVER_CREATE_PRECONDITIONER_FAILED:
OpmLog::warning("cusparseSolver could not create preconditioner, perhaps there is still a 0.0 on the diagonal of a block on the diagonal");
break;
default:
OpmLog::warning("cusparseSolver returned unknown status code");
}
res.iterations = result.iterations;
res.reduction = result.reduction;
res.converged = result.converged;
res.conv_rate = result.conv_rate;
res.elapsed = result.elapsed;
}else{
res.converged = false;
}
#endif // HAVE_CUDA
}
template <class BridgeVector>
void BdaBridge::get_result(BridgeVector &x OPM_UNUSED) {
#if HAVE_CUDA
if (use_gpu) {
backend->post_process(static_cast<double*>(&(x[0][0])));
}
#endif
}
template void BdaBridge::solve_system< \
Dune::BCRSMatrix<Opm::MatrixBlock<double, 2, 2>, std::allocator<Opm::MatrixBlock<double, 2, 2> > > , \
Dune::BlockVector<Dune::FieldVector<double, 2>, std::allocator<Dune::FieldVector<double, 2> > > > \
(Dune::BCRSMatrix<Opm::MatrixBlock<double, 2, 2>, std::allocator<Opm::MatrixBlock<double, 2, 2> > > *mat, \
Dune::BlockVector<Dune::FieldVector<double, 2>, std::allocator<Dune::FieldVector<double, 2> > > &b, \
InverseOperatorResult &res);
template void BdaBridge::solve_system< \
Dune::BCRSMatrix<Opm::MatrixBlock<double, 3, 3>, std::allocator<Opm::MatrixBlock<double, 3, 3> > > , \
Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > > \
(Dune::BCRSMatrix<Opm::MatrixBlock<double, 3, 3>, std::allocator<Opm::MatrixBlock<double, 3, 3> > > *mat, \
Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > &b, \
InverseOperatorResult &res);
template void BdaBridge::solve_system< \
Dune::BCRSMatrix<Opm::MatrixBlock<double, 4, 4>, std::allocator<Opm::MatrixBlock<double, 4, 4> > > , \
Dune::BlockVector<Dune::FieldVector<double, 4>, std::allocator<Dune::FieldVector<double, 4> > > > \
(Dune::BCRSMatrix<Opm::MatrixBlock<double, 4, 4>, std::allocator<Opm::MatrixBlock<double, 4, 4> > > *mat, \
Dune::BlockVector<Dune::FieldVector<double, 4>, std::allocator<Dune::FieldVector<double, 4> > > &b, \
InverseOperatorResult &res);
template void BdaBridge::get_result< \
Dune::BlockVector<Dune::FieldVector<double, 2>, std::allocator<Dune::FieldVector<double, 2> > > > \
(Dune::BlockVector<Dune::FieldVector<double, 2>, std::allocator<Dune::FieldVector<double, 2> > > &x);
template void BdaBridge::get_result< \
Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > > \
(Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > &x);
template void BdaBridge::get_result< \
Dune::BlockVector<Dune::FieldVector<double, 4>, std::allocator<Dune::FieldVector<double, 4> > > > \
(Dune::BlockVector<Dune::FieldVector<double, 4>, std::allocator<Dune::FieldVector<double, 4> > > &x);
}

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@ -0,0 +1,73 @@
/*
Copyright 2019 Equinor ASA
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 BDABRIDGE_HEADER_INCLUDED
#define BDABRIDGE_HEADER_INCLUDED
#include <config.h>
#include "dune/istl/solver.hh" // for struct InverseOperatorResult
#include "dune/istl/bcrsmatrix.hh"
#include <opm/simulators/linalg/matrixblock.hh>
#if HAVE_CUDA
#include <opm/simulators/linalg/bda/cusparseSolverBackend.hpp>
#endif
namespace Opm
{
typedef Dune::InverseOperatorResult InverseOperatorResult;
/// BdaBridge acts as interface between opm-simulators with the cusparseSolver
/// if CUDA was not found during CMake, function bodies of this class are empty
class BdaBridge
{
private:
#if HAVE_CUDA
std::unique_ptr<cusparseSolverBackend> backend;
#endif
bool use_gpu;
public:
/// Construct a BdaBridge
/// \param[in] use_gpu true iff the cusparseSolver is used, is passed via command-line: '--use-gpu=[true|false]'
/// \param[in] linear_solver_verbosity verbosity of cusparseSolver
/// \param[in] maxit maximum number of iterations for cusparseSolver
/// \param[in] tolerance required relative tolerance for cusparseSolver
BdaBridge(bool use_gpu, int linear_solver_verbosity, int maxit, double tolerance);
/// Solve linear system, A*x = b
/// \param[in] mat matrix A, should be of type Dune::BCRSMatrix
/// \param[in] b vector b, should be of type Dune::BlockVector
/// \param[in] result summary of solver result
template <class BridgeMatrix, class BridgeVector>
void solve_system(BridgeMatrix *mat, BridgeVector &b, InverseOperatorResult &result);
/// Get the resulting x vector
/// \param[inout] x vector x, should be of type Dune::BlockVector
template <class BridgeVector>
void get_result(BridgeVector &x);
}; // end class BdaBridge
}
#endif

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@ -0,0 +1,44 @@
/*
Copyright 2019 Equinor ASA
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 BDARESULT_HEADER_INCLUDED
#define BDARESULT_HEADER_INCLUDED
namespace Opm
{
/// This class is based on InverseOperatorResult struct from dune/istl/solver.hh
/// It is needed to prevent a compile error in basearray.hh, the nvcc compiler might not support all features in there
class BdaResult
{
public:
int iterations = 0; // number of iterations
double reduction = 0.0; // reduction of norm, norm_start / norm_final
bool converged = false; // true iff the linear solver reached the desired norm within maxit iterations
double conv_rate = 0.0; // average reduction of norm per iteration, usually calculated with 'static_cast<double>(pow(res.reduction,1.0/it));'
double elapsed = 0.0; // time in seconds to run the linear solver
// Dune 2.6 has a member 'double condition_estimate = -1' in InverseOperatorResult
}; // end class BdaResult
}
#endif

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@ -0,0 +1,41 @@
/*
Copyright 2019 Equinor ASA
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 CUDA_HEADER_HEADER_INCLUDED
#define CUDA_HEADER_HEADER_INCLUDED
#include <iostream>
/// Runtime error checking of CUDA functions
/// Usage:
/// cudaMalloc(...);
/// cudaCheckLastError("Error could not allocate memory");
///
#define cudaCheckLastError(msg) __cudaCheckError( __FILE__, __LINE__, #msg )
inline void __cudaCheckError(const char *file, const int line, const char *msg){
cudaError err = cudaGetLastError();
if (cudaSuccess != err){
std::cerr << "cudaCheckError() failed at " << file << ":" << line << ": " << cudaGetErrorString(err) << std::endl;
std::cerr << "BDA error message: " << msg << std::endl;
exit(1);
}
}
#endif

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@ -0,0 +1,499 @@
/*
Copyright 2019 Equinor ASA
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 __NVCC__
#error "Cannot compile for cusparse: NVIDIA compiler not found"
#endif
#include <cstdio>
#include <cstdlib>
#include <cuda_runtime.h>
#include <iostream>
#include <sys/time.h>
#include <sstream>
#include <opm/common/OpmLog/OpmLog.hpp>
#include <opm/simulators/linalg/bda/cusparseSolverBackend.hpp>
#include <opm/simulators/linalg/bda/BdaResult.hpp>
#include <opm/simulators/linalg/bda/cuda_header.hpp>
#include "cublas_v2.h"
#include "cusparse_v2.h"
// For more information about cusparse, check https://docs.nvidia.com/cuda/cusparse/index.html
namespace Opm
{
const cusparseSolvePolicy_t policy = CUSPARSE_SOLVE_POLICY_USE_LEVEL;
const cusparseOperation_t operation = CUSPARSE_OPERATION_NON_TRANSPOSE;
const cusparseDirection_t order = CUSPARSE_DIRECTION_ROW;
double second(void) {
struct timeval tv;
gettimeofday(&tv, nullptr);
return (double)tv.tv_sec + (double)tv.tv_usec / 1000000.0;
}
cusparseSolverBackend::cusparseSolverBackend(int verbosity_, int maxit_, double tolerance_) : verbosity(verbosity_), maxit(maxit_), tolerance(tolerance_), minit(0) {
}
cusparseSolverBackend::~cusparseSolverBackend() {
finalize();
}
void cusparseSolverBackend::gpu_pbicgstab(BdaResult& res) {
double t_total1, t_total2;
int n = N;
double rho = 1.0, rhop;
double alpha, nalpha, beta;
double omega, nomega, tmp1, tmp2;
double norm, norm_0;
double zero = 0.0;
double one = 1.0;
double mone = -1.0;
float it;
t_total1 = second();
cusparseDbsrmv(cusparseHandle, order, operation, Nb, Nb, nnzb, &one, descr_M, d_bVals, d_bRows, d_bCols, BLOCK_SIZE, d_x, &zero, d_r);
cublasDscal(cublasHandle, n, &mone, d_r, 1);
cublasDaxpy(cublasHandle, n, &one, d_b, 1, d_r, 1);
cublasDcopy(cublasHandle, n, d_r, 1, d_rw, 1);
cublasDcopy(cublasHandle, n, d_r, 1, d_p, 1);
cublasDnrm2(cublasHandle, n, d_r, 1, &norm_0);
if (verbosity > 1) {
std::ostringstream out;
out << std::scientific << "cusparseSolver initial norm: " << norm_0;
OpmLog::info(out.str());
}
for (it = 0.5; it < maxit; it+=0.5) {
rhop = rho;
cublasDdot(cublasHandle, n, d_rw, 1, d_r, 1, &rho);
if (it > 1) {
beta = (rho/rhop) * (alpha/omega);
nomega = -omega;
cublasDaxpy(cublasHandle, n, &nomega, d_v, 1, d_p, 1);
cublasDscal(cublasHandle, n, &beta, d_p, 1);
cublasDaxpy(cublasHandle, n, &one, d_r, 1, d_p, 1);
}
// apply ilu0
cusparseDbsrsv2_solve(cusparseHandle, order, \
operation, Nb, nnzb, &one, \
descr_L, d_mVals, d_mRows, d_mCols, BLOCK_SIZE, info_L, d_p, d_t, policy, d_buffer);
cusparseDbsrsv2_solve(cusparseHandle, order, \
operation, Nb, nnzb, &one, \
descr_U, d_mVals, d_mRows, d_mCols, BLOCK_SIZE, info_U, d_t, d_pw, policy, d_buffer);
// spmv
cusparseDbsrmv(cusparseHandle, order, \
operation, Nb, Nb, nnzb, \
&one, descr_M, d_bVals, d_bRows, d_bCols, BLOCK_SIZE, d_pw, &zero, d_v);
cublasDdot(cublasHandle, n, d_rw, 1, d_v, 1, &tmp1);
alpha = rho / tmp1;
nalpha = -alpha;
cublasDaxpy(cublasHandle, n, &nalpha, d_v, 1, d_r, 1);
cublasDaxpy(cublasHandle, n, &alpha, d_pw, 1, d_x, 1);
cublasDnrm2(cublasHandle, n, d_r, 1, &norm);
if (norm < tolerance * norm_0 && it > minit) {
break;
}
it += 0.5;
// apply ilu0
cusparseDbsrsv2_solve(cusparseHandle, order, \
operation, Nb, nnzb, &one, \
descr_L, d_mVals, d_mRows, d_mCols, BLOCK_SIZE, info_L, d_r, d_t, policy, d_buffer);
cusparseDbsrsv2_solve(cusparseHandle, order, \
operation, Nb, nnzb, &one, \
descr_U, d_mVals, d_mRows, d_mCols, BLOCK_SIZE, info_U, d_t, d_s, policy, d_buffer);
// spmv
cusparseDbsrmv(cusparseHandle, order, \
operation, Nb, Nb, nnzb, &one, descr_M, \
d_bVals, d_bRows, d_bCols, BLOCK_SIZE, d_s, &zero, d_t);
cublasDdot(cublasHandle, n, d_t, 1, d_r, 1, &tmp1);
cublasDdot(cublasHandle, n, d_t, 1, d_t, 1, &tmp2);
omega = tmp1 / tmp2;
nomega = -omega;
cublasDaxpy(cublasHandle, n, &omega, d_s, 1, d_x, 1);
cublasDaxpy(cublasHandle, n, &nomega, d_t, 1, d_r, 1);
cublasDnrm2(cublasHandle, n, d_r, 1, &norm);
if (norm < tolerance * norm_0 && it > minit) {
break;
}
if (verbosity > 1) {
std::ostringstream out;
out << "it: " << it << std::scientific << ", norm: " << norm;
OpmLog::info(out.str());
}
}
t_total2 = second();
res.iterations = std::min(it, (float)maxit);
res.reduction = norm/norm_0;
res.conv_rate = static_cast<double>(pow(res.reduction,1.0/it));
res.elapsed = t_total2 - t_total1;
res.converged = (it != (maxit + 0.5));
if (verbosity > 0) {
std::ostringstream out;
out << "=== converged: " << res.converged << ", conv_rate: " << res.conv_rate << ", time: " << res.elapsed << \
", time per iteration: " << res.elapsed/it << ", iterations: " << it;
OpmLog::info(out.str());
}
}
void cusparseSolverBackend::initialize(int N, int nnz, int dim) {
this->N = N;
this->nnz = nnz;
this->BLOCK_SIZE = dim;
this->nnzb = nnz/BLOCK_SIZE/BLOCK_SIZE;
Nb = (N + dim - 1) / dim;
std::ostringstream out;
out << "Initializing GPU, matrix size: " << N << " blocks, nnz: " << nnzb << " blocks";
OpmLog::info(out.str());
out.str("");
out.clear();
out << "Minit: " << minit << ", maxit: " << maxit << std::scientific << ", tolerance: " << tolerance;
OpmLog::info(out.str());
int deviceID = 0;
cudaSetDevice(deviceID);
cudaCheckLastError("Could not get device");
struct cudaDeviceProp props;
cudaGetDeviceProperties(&props, deviceID);
cudaCheckLastError("Could not get device properties");
out.str("");
out.clear();
out << "Name GPU: " << props.name << ", Compute Capability: " << props.major << "." << props.minor;
OpmLog::info(out.str());
cudaStreamCreate(&stream);
cudaCheckLastError("Could not create stream");
cublasCreate(&cublasHandle);
cudaCheckLastError("Could not create cublasHandle");
cusparseCreate(&cusparseHandle);
cudaCheckLastError("Could not create cusparseHandle");
cudaMalloc((void**)&d_x, sizeof(double) * N);
cudaMalloc((void**)&d_b, sizeof(double) * N);
cudaMalloc((void**)&d_r, sizeof(double) * N);
cudaMalloc((void**)&d_rw,sizeof(double) * N);
cudaMalloc((void**)&d_p, sizeof(double) * N);
cudaMalloc((void**)&d_pw,sizeof(double) * N);
cudaMalloc((void**)&d_s, sizeof(double) * N);
cudaMalloc((void**)&d_t, sizeof(double) * N);
cudaMalloc((void**)&d_v, sizeof(double) * N);
cudaMalloc((void**)&d_bVals, sizeof(double) * nnz);
cudaMalloc((void**)&d_bCols, sizeof(double) * nnz);
cudaMalloc((void**)&d_bRows, sizeof(double) * (Nb+1));
cudaMalloc((void**)&d_mVals, sizeof(double) * nnz);
cudaCheckLastError("Could not allocate enough memory on GPU");
cublasSetStream(cublasHandle, stream);
cudaCheckLastError("Could not set stream to cublas");
cusparseSetStream(cusparseHandle, stream);
cudaCheckLastError("Could not set stream to cusparse");
cudaMallocHost((void**)&x, sizeof(double) * N);
cudaCheckLastError("Could not allocate pinned host memory");
initialized = true;
} // end initialize()
void cusparseSolverBackend::finalize() {
cudaFree(d_x);
cudaFree(d_b);
cudaFree(d_r);
cudaFree(d_rw);
cudaFree(d_p);
cudaFree(d_pw);
cudaFree(d_s);
cudaFree(d_t);
cudaFree(d_v);
cudaFree(d_mVals);
cudaFree(d_bVals);
cudaFree(d_bCols);
cudaFree(d_bRows);
cudaFree(d_buffer);
cusparseDestroyBsrilu02Info(info_M);
cusparseDestroyBsrsv2Info(info_L);
cusparseDestroyBsrsv2Info(info_U);
cusparseDestroyMatDescr(descr_B);
cusparseDestroyMatDescr(descr_M);
cusparseDestroyMatDescr(descr_L);
cusparseDestroyMatDescr(descr_U);
cusparseDestroy(cusparseHandle);
cublasDestroy(cublasHandle);
cudaHostUnregister(vals);
cudaHostUnregister(cols);
cudaHostUnregister(rows);
cudaStreamDestroy(stream);
cudaFreeHost(x);
} // end finalize()
void cusparseSolverBackend::copy_system_to_gpu(double *vals, int *rows, int *cols, double *b) {
double t1, t2;
if (verbosity > 2) {
t1 = second();
}
// information cudaHostRegister: https://docs.nvidia.com/cuda/cuda-runtime-api/group__CUDART__MEMORY.html#group__CUDART__MEMORY_1ge8d5c17670f16ac4fc8fcb4181cb490c
// possible flags for cudaHostRegister: cudaHostRegisterDefault, cudaHostRegisterPortable, cudaHostRegisterMapped, cudaHostRegisterIoMemory
cudaHostRegister(vals, nnz * sizeof(double), cudaHostRegisterDefault);
cudaHostRegister(cols, nnz * sizeof(int), cudaHostRegisterDefault);
cudaHostRegister(rows, (Nb+1) * sizeof(int), cudaHostRegisterDefault);
cudaHostRegister(b, N * sizeof(double), cudaHostRegisterDefault);
cudaMemcpyAsync(d_bVals, vals, nnz * sizeof(double), cudaMemcpyHostToDevice, stream);
cudaMemcpyAsync(d_bCols, cols, nnz * sizeof(int), cudaMemcpyHostToDevice, stream);
cudaMemcpyAsync(d_bRows, rows, (Nb+1) * sizeof(int), cudaMemcpyHostToDevice, stream);
cudaMemcpyAsync(d_b, b, N * sizeof(double), cudaMemcpyHostToDevice, stream);
cudaMemsetAsync(d_x, 0, sizeof(double) * N, stream);
this->vals = vals;
this->cols = cols;
this->rows = rows;
if (verbosity > 2) {
cudaStreamSynchronize(stream);
t2 = second();
std::ostringstream out;
out << "cusparseSolver::copy_system_to_gpu(): " << t2-t1 << " s";
OpmLog::info(out.str());
}
} // end copy_system_to_gpu()
// don't copy rowpointers and colindices, they stay the same
void cusparseSolverBackend::update_system_on_gpu(double *vals, double *b) {
double t1, t2;
if (verbosity > 2) {
t1 = second();
}
cudaMemcpyAsync(d_bVals, vals, nnz * sizeof(double), cudaMemcpyHostToDevice, stream);
cudaMemcpyAsync(d_b, b, N * sizeof(double), cudaMemcpyHostToDevice, stream);
cudaMemsetAsync(d_x, 0, sizeof(double) * N, stream);
if (verbosity > 2) {
cudaStreamSynchronize(stream);
t2 = second();
std::ostringstream out;
out << "cusparseSolver::update_system_on_gpu(): " << t2-t1 << " s";
OpmLog::info(out.str());
}
} // end update_system_on_gpu()
void cusparseSolverBackend::reset_prec_on_gpu() {
cudaMemcpyAsync(d_mVals, d_bVals, nnz * sizeof(double), cudaMemcpyDeviceToDevice, stream);
}
bool cusparseSolverBackend::analyse_matrix() {
int d_bufferSize_M, d_bufferSize_L, d_bufferSize_U, d_bufferSize;
double t1, t2;
if (verbosity > 2) {
t1 = second();
}
cusparseCreateMatDescr(&descr_B);
cusparseCreateMatDescr(&descr_M);
cusparseSetMatType(descr_B, CUSPARSE_MATRIX_TYPE_GENERAL);
cusparseSetMatType(descr_M, CUSPARSE_MATRIX_TYPE_GENERAL);
const cusparseIndexBase_t base_type = CUSPARSE_INDEX_BASE_ZERO; // matrices from Flow are base0
cusparseSetMatIndexBase(descr_B, base_type);
cusparseSetMatIndexBase(descr_M, base_type);
cusparseCreateMatDescr(&descr_L);
cusparseSetMatIndexBase(descr_L, base_type);
cusparseSetMatType(descr_L, CUSPARSE_MATRIX_TYPE_GENERAL);
cusparseSetMatFillMode(descr_L, CUSPARSE_FILL_MODE_LOWER);
cusparseSetMatDiagType(descr_L, CUSPARSE_DIAG_TYPE_UNIT);
cusparseCreateMatDescr(&descr_U);
cusparseSetMatIndexBase(descr_U, base_type);
cusparseSetMatType(descr_U, CUSPARSE_MATRIX_TYPE_GENERAL);
cusparseSetMatFillMode(descr_U, CUSPARSE_FILL_MODE_UPPER);
cusparseSetMatDiagType(descr_U, CUSPARSE_DIAG_TYPE_NON_UNIT);
cudaCheckLastError("Could not initialize matrix descriptions");
cusparseCreateBsrilu02Info(&info_M);
cusparseCreateBsrsv2Info(&info_L);
cusparseCreateBsrsv2Info(&info_U);
cudaCheckLastError("Could not create analysis info");
cusparseDbsrilu02_bufferSize(cusparseHandle, order, Nb, nnzb,
descr_M, d_bVals, d_bRows, d_bCols, BLOCK_SIZE, info_M, &d_bufferSize_M);
cusparseDbsrsv2_bufferSize(cusparseHandle, order, operation, Nb, nnzb,
descr_L, d_bVals, d_bRows, d_bCols, BLOCK_SIZE, info_L, &d_bufferSize_L);
cusparseDbsrsv2_bufferSize(cusparseHandle, order, operation, Nb, nnzb,
descr_U, d_bVals, d_bRows, d_bCols, BLOCK_SIZE, info_U, &d_bufferSize_U);
cudaCheckLastError();
d_bufferSize = std::max(d_bufferSize_M, std::max(d_bufferSize_L, d_bufferSize_U));
cudaMalloc((void**)&d_buffer, d_bufferSize);
// analysis of ilu LU decomposition
cusparseDbsrilu02_analysis(cusparseHandle, order, \
Nb, nnzb, descr_B, d_bVals, d_bRows, d_bCols, \
BLOCK_SIZE, info_M, policy, d_buffer);
int structural_zero;
cusparseStatus_t status = cusparseXbsrilu02_zeroPivot(cusparseHandle, info_M, &structural_zero);
if (CUSPARSE_STATUS_ZERO_PIVOT == status) {
return false;
}
// analysis of ilu apply
cusparseDbsrsv2_analysis(cusparseHandle, order, operation, \
Nb, nnzb, descr_L, d_bVals, d_bRows, d_bCols, \
BLOCK_SIZE, info_L, policy, d_buffer);
cusparseDbsrsv2_analysis(cusparseHandle, order, operation, \
Nb, nnzb, descr_U, d_bVals, d_bRows, d_bCols, \
BLOCK_SIZE, info_U, policy, d_buffer);
cudaCheckLastError("Could not analyse level information");
if (verbosity > 2) {
cudaStreamSynchronize(stream);
t2 = second();
std::ostringstream out;
out << "cusparseSolver::analyse_matrix(): " << t2-t1 << " s";
OpmLog::info(out.str());
}
return true;
} // end analyse_matrix()
bool cusparseSolverBackend::create_preconditioner() {
double t1, t2;
if (verbosity > 2) {
t1 = second();
}
d_mCols = d_bCols;
d_mRows = d_bRows;
cusparseDbsrilu02(cusparseHandle, order, \
Nb, nnzb, descr_M, d_mVals, d_mRows, d_mCols, \
BLOCK_SIZE, info_M, policy, d_buffer);
int structural_zero;
// cusparseXbsrilu02_zeroPivot() calls cudaDeviceSynchronize()
cusparseStatus_t status = cusparseXbsrilu02_zeroPivot(cusparseHandle, info_M, &structural_zero);
if (CUSPARSE_STATUS_ZERO_PIVOT == status) {
return false;
}
if (verbosity > 2) {
cudaStreamSynchronize(stream);
t2 = second();
std::ostringstream out;
out << "cusparseSolver::create_preconditioner(): " << t2-t1 << " s";
OpmLog::info(out.str());
}
return true;
} // end create_preconditioner()
void cusparseSolverBackend::solve_system(BdaResult &res) {
// actually solve
gpu_pbicgstab(res);
cudaStreamSynchronize(stream);
cudaCheckLastError("Something went wrong during the GPU solve");
} // end solve_system()
// copy result to host memory
// caller must be sure that x is a valid array
void cusparseSolverBackend::post_process(double *x) {
if (!initialized) {
cudaHostRegister(x, N * sizeof(double), cudaHostRegisterDefault);
}
double t1, t2;
if (verbosity > 2) {
t1 = second();
}
cudaMemcpyAsync(x, d_x, N * sizeof(double), cudaMemcpyDeviceToHost, stream);
cudaStreamSynchronize(stream);
if (verbosity > 2) {
t2 = second();
std::ostringstream out;
out << "cusparseSolver::post_process(): " << t2-t1 << " s";
OpmLog::info(out.str());
}
} // end post_process()
typedef cusparseSolverBackend::cusparseSolverStatus cusparseSolverStatus;
cusparseSolverStatus cusparseSolverBackend::solve_system(int N, int nnz, int dim, double *vals, int *rows, int *cols, double *b, BdaResult &res) {
if (initialized == false) {
initialize(N, nnz, dim);
copy_system_to_gpu(vals, rows, cols, b);
}else{
update_system_on_gpu(vals, b);
}
if (analysis_done == false) {
if (!analyse_matrix()) {
return cusparseSolverStatus::CUSPARSE_SOLVER_ANALYSIS_FAILED;
}
}
reset_prec_on_gpu();
if (create_preconditioner()) {
solve_system(res);
}else{
return cusparseSolverStatus::CUSPARSE_SOLVER_CREATE_PRECONDITIONER_FAILED;
}
return cusparseSolverStatus::CUSPARSE_SOLVER_SUCCESS;
}
}

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@ -0,0 +1,151 @@
/*
Copyright 2019 Equinor ASA
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_CUSPARSESOLVER_BACKEND_HEADER_INCLUDED
#define OPM_CUSPARSESOLVER_BACKEND_HEADER_INCLUDED
#include "cublas_v2.h"
#include "cusparse_v2.h"
#include "opm/simulators/linalg/bda/BdaResult.hpp"
namespace Opm
{
/// This class implements a cusparse-based ilu0-bicgstab solver on GPU
class cusparseSolverBackend{
private:
int minit;
int maxit;
double tolerance;
cublasHandle_t cublasHandle;
cusparseHandle_t cusparseHandle;
cudaStream_t stream;
cusparseMatDescr_t descr_B, descr_M, descr_L, descr_U;
bsrilu02Info_t info_M;
bsrsv2Info_t info_L, info_U;
// b: bsr matrix, m: preconditioner
double *d_bVals, *d_mVals;
int *d_bCols, *d_mCols;
int *d_bRows, *d_mRows;
double *d_x, *d_b, *d_r, *d_rw, *d_p;
double *d_pw, *d_s, *d_t, *d_v;
double *vals;
int *cols, *rows;
double *x, *b;
void *d_buffer;
int N, Nb, nnz, nnzb;
int BLOCK_SIZE;
bool initialized = false;
bool analysis_done = false;
// verbosity
// 0: print nothing during solves, only when initializing
// 1: print number of iterations and final norm
// 2: also print norm each iteration
// 3: also print timings of different backend functions
int verbosity = 0;
/// Solve linear system using ilu0-bicgstab
/// \param[inout] res summary of solver result
void gpu_pbicgstab(BdaResult& res);
/// Initialize GPU and allocate memory
/// \param[in] N number of nonzeroes, divide by dim*dim to get number of blocks
/// \param[in] nnz number of nonzeroes, divide by dim*dim to get number of blocks
/// \param[in] dim size of block
void initialize(int N, int nnz, int dim);
/// Clean memory
void finalize();
/// Copy linear system to GPU
/// \param[in] vals array of nonzeroes, each block is stored row-wise and contiguous, contains nnz values
/// \param[in] rows array of rowPointers, contains N/dim+1 values
/// \param[in] cols array of columnIndices, contains nnz values
/// \param[in] b input vector, contains N values
void copy_system_to_gpu(double *vals, int *rows, int *cols, double *b);
// Update linear system on GPU, don't copy rowpointers and colindices, they stay the same
/// \param[in] vals array of nonzeroes, each block is stored row-wise and contiguous, contains nnz values
/// \param[in] b input vector, contains N values
void update_system_on_gpu(double *vals, double *b);
/// Reset preconditioner on GPU, ilu0-decomposition is done inplace by cusparse
void reset_prec_on_gpu();
/// Analyse sparsity pattern to extract parallelism
/// \return true iff analysis was successful
bool analyse_matrix();
/// Perform ilu0-decomposition
/// \return true iff decomposition was successful
bool create_preconditioner();
/// Solve linear system
/// \param[inout] res summary of solver result
void solve_system(BdaResult &res);
public:
enum class cusparseSolverStatus {
CUSPARSE_SOLVER_SUCCESS,
CUSPARSE_SOLVER_ANALYSIS_FAILED,
CUSPARSE_SOLVER_CREATE_PRECONDITIONER_FAILED,
CUSPARSE_SOLVER_UNKNOWN_ERROR
};
/// Construct a cusparseSolver
/// \param[in] linear_solver_verbosity verbosity of cusparseSolver
/// \param[in] maxit maximum number of iterations for cusparseSolver
/// \param[in] tolerance required relative tolerance for cusparseSolver
cusparseSolverBackend(int linear_solver_verbosity, int maxit, double tolerance);
/// Destroy a cusparseSolver, and free memory
~cusparseSolverBackend();
/// Solve linear system, A*x = b, matrix A must be in blocked-CSR format
/// \param[in] N number of rows, divide by dim to get number of blockrows
/// \param[in] nnz number of nonzeroes, divide by dim*dim to get number of blocks
/// \param[in] dim size of block
/// \param[in] vals array of nonzeroes, each block is stored row-wise and contiguous, contains nnz values
/// \param[in] rows array of rowPointers, contains N/dim+1 values
/// \param[in] cols array of columnIndices, contains nnz values
/// \param[in] b input vector, contains N values
/// \param[inout] res summary of solver result
/// \return status code
cusparseSolverStatus solve_system(int N, int nnz, int dim, double *vals, int *rows, int *cols, double *b, BdaResult &res);
/// Post processing after linear solve, now only copies resulting x vector back
/// \param[inout] x resulting x vector, caller must guarantee that x points to a valid array
void post_process(double *x);
}; // end class cusparseSolverBackend
}
#endif