--- /dev/null
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2022 - 2023 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+//
+// Description:
+//
+// A performance benchmark based on step 37 (without variable coefficient)
+// that measures timings for grid creation, setup of unknowns, multigrid
+// levels and solve for a Poisson problem with the performance-oriented
+// matrix-free framework. Similar to timing_step_37 with the difference
+// that instead MGTransferMatrixFree MGTransferMF (former
+// MGTransferGlobalCoarsening) is used. This PR is meant to track the
+// performance improvements.
+//
+// Status: experimental
+//
+
+#include <deal.II/base/function.h>
+#include <deal.II/base/logstream.h>
+#include <deal.II/base/quadrature_lib.h>
+#include <deal.II/base/timer.h>
+#include <deal.II/base/utilities.h>
+
+#include <deal.II/distributed/tria.h>
+
+#include <deal.II/dofs/dof_handler.h>
+#include <deal.II/dofs/dof_renumbering.h>
+#include <deal.II/dofs/dof_tools.h>
+
+#include <deal.II/fe/fe_q.h>
+#include <deal.II/fe/fe_values.h>
+
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/grid/grid_refinement.h>
+#include <deal.II/grid/tria.h>
+
+#include <deal.II/lac/affine_constraints.h>
+#include <deal.II/lac/precondition.h>
+#include <deal.II/lac/solver_cg.h>
+
+#include <deal.II/matrix_free/fe_evaluation.h>
+#include <deal.II/matrix_free/matrix_free.h>
+#include <deal.II/matrix_free/operators.h>
+
+#include <deal.II/multigrid/mg_coarse.h>
+#include <deal.II/multigrid/mg_matrix.h>
+#include <deal.II/multigrid/mg_smoother.h>
+#include <deal.II/multigrid/mg_tools.h>
+#include <deal.II/multigrid/mg_transfer_global_coarsening.h>
+#include <deal.II/multigrid/multigrid.h>
+
+#include <deal.II/numerics/vector_tools.h>
+
+#include <fstream>
+#include <iostream>
+#include <memory>
+
+#define ENABLE_MPI
+
+#include "performance_test_driver.h"
+
+using namespace dealii;
+
+dealii::ConditionalOStream debug_output(std::cout, false);
+
+const unsigned int degree_finite_element = 3;
+
+
+
+template <int dim, int fe_degree, typename number>
+class LaplaceOperator
+ : public MatrixFreeOperators::Base<dim,
+ LinearAlgebra::distributed::Vector<number>>
+{
+public:
+ using value_type = number;
+
+ LaplaceOperator();
+
+ void
+ vmult(LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src) const;
+
+ void
+ vmult(LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src,
+ const std::function<void(const unsigned int, const unsigned int)>
+ &operation_before_loop,
+ const std::function<void(const unsigned int, const unsigned int)>
+ &operation_after_loop) const;
+
+ virtual void
+ compute_diagonal() override;
+
+private:
+ virtual void
+ apply_add(
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src) const override;
+
+ void
+ local_apply(const MatrixFree<dim, number> & data,
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src,
+ const std::pair<unsigned int, unsigned int> &cell_range) const;
+
+ void
+ local_compute_diagonal(
+ const MatrixFree<dim, number> & data,
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const unsigned int & dummy,
+ const std::pair<unsigned int, unsigned int> &cell_range) const;
+};
+
+
+
+template <int dim, int fe_degree, typename number>
+LaplaceOperator<dim, fe_degree, number>::LaplaceOperator()
+ : MatrixFreeOperators::Base<dim, LinearAlgebra::distributed::Vector<number>>()
+{}
+
+
+
+template <int dim, int fe_degree, typename number>
+void
+LaplaceOperator<dim, fe_degree, number>::local_apply(
+ const MatrixFree<dim, number> & data,
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src,
+ const std::pair<unsigned int, unsigned int> & cell_range) const
+{
+ FEEvaluation<dim, fe_degree, fe_degree + 1, 1, number> phi(data);
+
+ for (unsigned int cell = cell_range.first; cell < cell_range.second; ++cell)
+ {
+ phi.reinit(cell);
+ phi.gather_evaluate(src, EvaluationFlags::gradients);
+ for (unsigned int q = 0; q < phi.n_q_points; ++q)
+ phi.submit_gradient(phi.get_gradient(q), q);
+ phi.integrate_scatter(EvaluationFlags::gradients, dst);
+ }
+}
+
+
+
+template <int dim, int fe_degree, typename number>
+void
+LaplaceOperator<dim, fe_degree, number>::apply_add(
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src) const
+{
+ this->data->cell_loop(&LaplaceOperator::local_apply, this, dst, src);
+}
+
+
+
+template <int dim, int fe_degree, typename number>
+void
+LaplaceOperator<dim, fe_degree, number>::vmult(
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src) const
+{
+ this->data->cell_loop(&LaplaceOperator::local_apply, this, dst, src, true);
+ for (const unsigned int i : this->data->get_constrained_dofs())
+ dst.local_element(i) = src.local_element(i);
+}
+
+
+
+template <int dim, int fe_degree, typename number>
+void
+LaplaceOperator<dim, fe_degree, number>::vmult(
+ LinearAlgebra::distributed::Vector<number> & dst,
+ const LinearAlgebra::distributed::Vector<number> &src,
+ const std::function<void(const unsigned int, const unsigned int)>
+ &operation_before_loop,
+ const std::function<void(const unsigned int, const unsigned int)>
+ &operation_after_loop) const
+{
+ this->data->cell_loop(&LaplaceOperator::local_apply,
+ this,
+ dst,
+ src,
+ operation_before_loop,
+ operation_after_loop);
+ for (const unsigned int i : this->data->get_constrained_dofs())
+ dst.local_element(i) = src.local_element(i);
+}
+
+
+
+template <int dim, int fe_degree, typename number>
+void
+LaplaceOperator<dim, fe_degree, number>::compute_diagonal()
+{
+ this->inverse_diagonal_entries.reset(
+ new DiagonalMatrix<LinearAlgebra::distributed::Vector<number>>());
+ LinearAlgebra::distributed::Vector<number> &inverse_diagonal =
+ this->inverse_diagonal_entries->get_vector();
+ this->data->initialize_dof_vector(inverse_diagonal);
+ unsigned int dummy = 0;
+ this->data->cell_loop(&LaplaceOperator::local_compute_diagonal,
+ this,
+ inverse_diagonal,
+ dummy);
+
+ this->set_constrained_entries_to_one(inverse_diagonal);
+
+ for (unsigned int i = 0; i < inverse_diagonal.locally_owned_size(); ++i)
+ {
+ Assert(inverse_diagonal.local_element(i) > 0.,
+ ExcMessage("No diagonal entry in a positive definite operator "
+ "should be zero"));
+ inverse_diagonal.local_element(i) =
+ 1. / inverse_diagonal.local_element(i);
+ }
+}
+
+
+
+template <int dim, int fe_degree, typename number>
+void
+LaplaceOperator<dim, fe_degree, number>::local_compute_diagonal(
+ const MatrixFree<dim, number> & data,
+ LinearAlgebra::distributed::Vector<number> &dst,
+ const unsigned int &,
+ const std::pair<unsigned int, unsigned int> &cell_range) const
+{
+ FEEvaluation<dim, fe_degree, fe_degree + 1, 1, number> phi(data);
+
+ AlignedVector<VectorizedArray<number>> diagonal(phi.dofs_per_cell);
+
+ for (unsigned int cell = cell_range.first; cell < cell_range.second; ++cell)
+ {
+ phi.reinit(cell);
+ for (unsigned int i = 0; i < phi.dofs_per_cell; ++i)
+ {
+ for (unsigned int j = 0; j < phi.dofs_per_cell; ++j)
+ phi.submit_dof_value(VectorizedArray<number>(), j);
+ phi.submit_dof_value(make_vectorized_array<number>(1.), i);
+
+ phi.evaluate(EvaluationFlags::gradients);
+ for (unsigned int q = 0; q < phi.n_q_points; ++q)
+ phi.submit_gradient(phi.get_gradient(q), q);
+ phi.integrate(EvaluationFlags::gradients);
+ diagonal[i] = phi.get_dof_value(i);
+ }
+ for (unsigned int i = 0; i < phi.dofs_per_cell; ++i)
+ phi.submit_dof_value(diagonal[i], i);
+ phi.distribute_local_to_global(dst);
+ }
+}
+
+
+
+template <int dim>
+class LaplaceProblem
+{
+public:
+ LaplaceProblem();
+
+ Measurement
+ run();
+
+private:
+ void
+ setup_grid();
+ void
+ setup_dofs();
+ void
+ setup_matrix_free();
+ void
+ assemble_rhs();
+ void
+ setup_transfer();
+ void
+ setup_smoother();
+ void
+ solve();
+
+ parallel::distributed::Triangulation<dim> triangulation;
+
+ FE_Q<dim> fe;
+ DoFHandler<dim> dof_handler;
+
+ MappingQ1<dim> mapping;
+
+ AffineConstraints<double> constraints;
+ using SystemMatrixType = LaplaceOperator<dim, degree_finite_element, double>;
+ SystemMatrixType system_matrix;
+
+ MGConstrainedDoFs mg_constrained_dofs;
+ using LevelMatrixType = LaplaceOperator<dim, degree_finite_element, float>;
+ MGLevelObject<LevelMatrixType> mg_matrices;
+
+ LinearAlgebra::distributed::Vector<double> solution;
+ LinearAlgebra::distributed::Vector<double> system_rhs;
+
+ MGTransferMF<dim, float> mg_transfer;
+
+ using SmootherType =
+ PreconditionChebyshev<LevelMatrixType,
+ LinearAlgebra::distributed::Vector<float>>;
+ mg::SmootherRelaxation<SmootherType,
+ LinearAlgebra::distributed::Vector<float>>
+ mg_smoother;
+};
+
+
+
+template <int dim>
+LaplaceProblem<dim>::LaplaceProblem()
+#ifdef DEAL_II_WITH_P4EST
+ : triangulation(
+ MPI_COMM_WORLD,
+ Triangulation<dim>::limit_level_difference_at_vertices,
+ parallel::distributed::Triangulation<dim>::construct_multigrid_hierarchy)
+#else
+ : triangulation(Triangulation<dim>::limit_level_difference_at_vertices)
+#endif
+ , fe(degree_finite_element)
+ , dof_handler(triangulation)
+{}
+
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::setup_grid()
+{
+ GridGenerator::hyper_cube(triangulation, 0., 1.);
+ switch (get_testing_environment())
+ {
+ case TestingEnvironment::light:
+ triangulation.refine_global(5);
+ break;
+ case TestingEnvironment::medium:
+ triangulation.refine_global(6);
+ break;
+ case TestingEnvironment::heavy:
+ triangulation.refine_global(7);
+ break;
+ }
+}
+
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::setup_dofs()
+{
+ system_matrix.clear();
+ mg_matrices.clear_elements();
+
+ dof_handler.distribute_dofs(fe);
+ dof_handler.distribute_mg_dofs();
+
+ debug_output << "Number of DoFs: " << dof_handler.n_dofs() << std::endl;
+
+ IndexSet locally_relevant_dofs;
+ DoFTools::extract_locally_relevant_dofs(dof_handler, locally_relevant_dofs);
+
+ constraints.clear();
+ constraints.reinit(locally_relevant_dofs);
+ DoFTools::make_hanging_node_constraints(dof_handler, constraints);
+ VectorTools::interpolate_boundary_values(
+ mapping, dof_handler, 0, Functions::ZeroFunction<dim>(), constraints);
+ constraints.close();
+
+ // Renumber DoFs
+ typename MatrixFree<dim, float>::AdditionalData additional_data;
+ additional_data.tasks_parallel_scheme =
+ MatrixFree<dim, float>::AdditionalData::none;
+
+ const std::set<types::boundary_id> dirichlet_boundary = {0};
+ mg_constrained_dofs.initialize(dof_handler);
+ mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
+ dirichlet_boundary);
+
+ for (unsigned int level = 0; level < triangulation.n_global_levels(); ++level)
+ {
+ IndexSet relevant_dofs;
+ DoFTools::extract_locally_relevant_level_dofs(dof_handler,
+ level,
+ relevant_dofs);
+ AffineConstraints<double> level_constraints;
+ level_constraints.reinit(relevant_dofs);
+ level_constraints.add_lines(
+ mg_constrained_dofs.get_boundary_indices(level));
+ level_constraints.close();
+ additional_data.mg_level = level;
+
+ DoFRenumbering::matrix_free_data_locality(dof_handler,
+ level_constraints,
+ additional_data);
+ }
+}
+
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::setup_matrix_free()
+{
+ typename MatrixFree<dim, double>::AdditionalData additional_data;
+ additional_data.tasks_parallel_scheme =
+ MatrixFree<dim, double>::AdditionalData::none;
+ additional_data.mapping_update_flags =
+ (update_gradients | update_JxW_values | update_quadrature_points);
+ std::shared_ptr<MatrixFree<dim, double>> system_mf_storage(
+ new MatrixFree<dim, double>());
+ system_mf_storage->reinit(mapping,
+ dof_handler,
+ constraints,
+ QGauss<1>(fe.degree + 1),
+ additional_data);
+ system_matrix.initialize(system_mf_storage);
+
+
+ system_matrix.initialize_dof_vector(solution);
+ system_matrix.initialize_dof_vector(system_rhs);
+
+ const unsigned int nlevels = triangulation.n_global_levels();
+ mg_matrices.resize(0, nlevels - 1);
+
+ const std::set<types::boundary_id> dirichlet_boundary = {0};
+ mg_constrained_dofs.initialize(dof_handler);
+ mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
+ dirichlet_boundary);
+
+ for (unsigned int level = 0; level < nlevels; ++level)
+ {
+ IndexSet relevant_dofs;
+ DoFTools::extract_locally_relevant_level_dofs(dof_handler,
+ level,
+ relevant_dofs);
+ AffineConstraints<double> level_constraints;
+ level_constraints.reinit(relevant_dofs);
+ level_constraints.add_lines(
+ mg_constrained_dofs.get_boundary_indices(level));
+ level_constraints.close();
+
+ typename MatrixFree<dim, float>::AdditionalData additional_data;
+ additional_data.tasks_parallel_scheme =
+ MatrixFree<dim, float>::AdditionalData::none;
+ additional_data.mapping_update_flags =
+ (update_gradients | update_JxW_values | update_quadrature_points);
+ additional_data.mg_level = level;
+ std::shared_ptr<MatrixFree<dim, float>> mg_mf_storage_level(
+ new MatrixFree<dim, float>());
+ mg_mf_storage_level->reinit(mapping,
+ dof_handler,
+ level_constraints,
+ QGauss<1>(fe.degree + 1),
+ additional_data);
+
+ mg_matrices[level].initialize(mg_mf_storage_level,
+ mg_constrained_dofs,
+ level);
+ }
+}
+
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::assemble_rhs()
+{
+ Timer time;
+
+ system_rhs = 0;
+ FEEvaluation<dim, degree_finite_element> phi(
+ *system_matrix.get_matrix_free());
+ for (unsigned int cell = 0;
+ cell < system_matrix.get_matrix_free()->n_cell_batches();
+ ++cell)
+ {
+ phi.reinit(cell);
+ for (unsigned int q = 0; q < phi.n_q_points; ++q)
+ phi.submit_value(make_vectorized_array<double>(1.0), q);
+ phi.integrate(EvaluationFlags::values);
+ phi.distribute_local_to_global(system_rhs);
+ }
+ system_rhs.compress(VectorOperation::add);
+}
+
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::setup_transfer()
+{
+ mg_transfer.initialize_constraints(mg_constrained_dofs);
+ std::vector<std::shared_ptr<const Utilities::MPI::Partitioner>> partitioners(
+ dof_handler.get_triangulation().n_global_levels());
+ for (unsigned int level = 0; level < partitioners.size(); ++level)
+ {
+ LinearAlgebra::distributed::Vector<float> vec;
+ mg_matrices[level].initialize_dof_vector(vec);
+ partitioners[level] = vec.get_partitioner();
+ }
+ mg_transfer.build(dof_handler, partitioners);
+}
+
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::setup_smoother()
+{
+ MGLevelObject<typename SmootherType::AdditionalData> smoother_data;
+ smoother_data.resize(0, triangulation.n_global_levels() - 1);
+ for (unsigned int level = 0; level < triangulation.n_global_levels(); ++level)
+ {
+ if (level > 0)
+ {
+ smoother_data[level].smoothing_range = 15.;
+ smoother_data[level].degree = 5;
+ smoother_data[level].eig_cg_n_iterations = 10;
+ }
+ else
+ {
+ smoother_data[0].smoothing_range = 1e-3;
+ smoother_data[0].degree = numbers::invalid_unsigned_int;
+ smoother_data[0].eig_cg_n_iterations = mg_matrices[0].m();
+ }
+ mg_matrices[level].compute_diagonal();
+ smoother_data[level].preconditioner =
+ mg_matrices[level].get_matrix_diagonal_inverse();
+ }
+ mg_smoother.initialize(mg_matrices, smoother_data);
+}
+
+
+template <int dim>
+void
+LaplaceProblem<dim>::solve()
+{
+ MGCoarseGridApplySmoother<LinearAlgebra::distributed::Vector<float>>
+ mg_coarse;
+ mg_coarse.initialize(mg_smoother);
+
+ mg::Matrix<LinearAlgebra::distributed::Vector<float>> mg_matrix(mg_matrices);
+
+ MGLevelObject<MatrixFreeOperators::MGInterfaceOperator<LevelMatrixType>>
+ mg_interface_matrices;
+ mg_interface_matrices.resize(0, triangulation.n_global_levels() - 1);
+ for (unsigned int level = 0; level < triangulation.n_global_levels(); ++level)
+ mg_interface_matrices[level].initialize(mg_matrices[level]);
+ mg::Matrix<LinearAlgebra::distributed::Vector<float>> mg_interface(
+ mg_interface_matrices);
+
+ Multigrid<LinearAlgebra::distributed::Vector<float>> mg(
+ mg_matrix, mg_coarse, mg_transfer, mg_smoother, mg_smoother);
+ mg.set_edge_matrices(mg_interface, mg_interface);
+
+ PreconditionMG<dim,
+ LinearAlgebra::distributed::Vector<float>,
+ MGTransferMF<dim, float>>
+ preconditioner(dof_handler, mg, mg_transfer);
+
+
+ SolverControl solver_control(100, 1e-12 * system_rhs.l2_norm());
+ SolverCG<LinearAlgebra::distributed::Vector<double>> cg(solver_control);
+
+ constraints.set_zero(solution);
+ cg.solve(system_matrix, solution, system_rhs, preconditioner);
+}
+
+
+
+template <int dim>
+Measurement
+LaplaceProblem<dim>::run()
+{
+ std::map<std::string, dealii::Timer> timer;
+
+ timer["setup_grid"].start();
+ setup_grid();
+ timer["setup_grid"].stop();
+
+ timer["setup_dofs"].start();
+ setup_dofs();
+ timer["setup_dofs"].stop();
+
+ timer["setup_matrix_free"].start();
+ setup_matrix_free();
+ timer["setup_matrix_free"].stop();
+
+ timer["assemble_rhs"].start();
+ assemble_rhs();
+ timer["assemble_rhs"].stop();
+
+ timer["setup_transfer"].start();
+ setup_transfer();
+ timer["setup_transfer"].stop();
+
+ timer["setup_smoother"].start();
+ setup_smoother();
+ timer["setup_smoother"].stop();
+
+ timer["solve"].start();
+ solve();
+ timer["solve"].stop();
+
+ const unsigned int n_repeat = 50;
+ timer["matvec_double"].start();
+ for (unsigned int t = 0; t < n_repeat; ++t)
+ system_matrix.vmult(system_rhs, solution);
+ timer["matvec_double"].stop();
+
+ LinearAlgebra::distributed::Vector<float> vec1, vec2;
+ mg_matrices[mg_matrices.max_level()].initialize_dof_vector(vec1);
+ vec2.reinit(vec1);
+ timer["matvec_float"].start();
+ for (unsigned int t = 0; t < n_repeat; ++t)
+ mg_matrices[mg_matrices.max_level()].vmult(vec2, vec1);
+ timer["matvec_float"].stop();
+
+ mg_matrices[mg_matrices.max_level() - 1].initialize_dof_vector(vec1);
+ vec2.reinit(vec1);
+ timer["matvec_float_coarser"].start();
+ for (unsigned int t = 0; t < n_repeat; ++t)
+ mg_matrices[mg_matrices.max_level() - 1].vmult(vec2, vec1);
+ timer["matvec_float_coarser"].stop();
+
+ debug_output << std::endl;
+ return {timer["setup_grid"].wall_time(),
+ timer["setup_dofs"].wall_time(),
+ timer["setup_matrix_free"].wall_time(),
+ timer["assemble_rhs"].wall_time(),
+ timer["setup_transfer"].wall_time(),
+ timer["setup_smoother"].wall_time(),
+ timer["solve"].wall_time(),
+ timer["matvec_double"].wall_time(),
+ timer["matvec_float"].wall_time(),
+ timer["matvec_float_coarser"].wall_time()};
+}
+
+
+std::tuple<Metric, unsigned int, std::vector<std::string>>
+describe_measurements()
+{
+ return {Metric::timing,
+ 4,
+ {"setup_grid",
+ "setup_dofs",
+ "setup_matrix_free",
+ "assemble_rhs",
+ "setup_transfer",
+ "setup_smoother",
+ "solve",
+ "matvec_double",
+ "matvec_float",
+ "matvec_float_coarser"}};
+}
+
+
+Measurement
+perform_single_measurement()
+{
+ return LaplaceProblem<3>().run();
+}
projects / dealii.git / commitdiff