From: Peter Munch Date: Sat, 25 Mar 2023 12:32:10 +0000 (+0100) Subject: Move OrthogonalizationStrategy into new file X-Git-Tag: v9.5.0-rc1~88^2 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d99b41db46cee4709f7bc2744f602121040e62e3;p=dealii.git Move OrthogonalizationStrategy into new file --- diff --git a/doc/news/changes/minor/20221208Munch b/doc/news/changes/minor/20221208Munch index e90bef2f41..4c7959e946 100644 --- a/doc/news/changes/minor/20221208Munch +++ b/doc/news/changes/minor/20221208Munch @@ -1,6 +1,7 @@ -New: SolverGMRES now also supports classical Gram-Schmidt orthonormalization +New: SolverGMRES and SolverFGMRES now also support classical +Gram-Schmidt orthonormalization alongside to the existing modified Gram-Schmidt algorithm. This -allows to reduce the cost of vector operations in terms of +algorithm allows to reduce the cost of vector operations in terms of communication latency and memory transfer significantly.
(Peter Munch, Martin Kronbichler, 2022/12/08) diff --git a/include/deal.II/lac/orthogonalization.h b/include/deal.II/lac/orthogonalization.h new file mode 100644 index 0000000000..69ff82cf98 --- /dev/null +++ b/include/deal.II/lac/orthogonalization.h @@ -0,0 +1,50 @@ +// --------------------------------------------------------------------- +// +// Copyright (C) 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. +// +// --------------------------------------------------------------------- + +#ifndef dealii_lac_orthogonalization_h +#define dealii_lac_orthogonalization_h + + +#include + +DEAL_II_NAMESPACE_OPEN + +namespace LinearAlgebra +{ + /** + * Supported orthogonalization strategies within SolverGMRES and + * SolverFGMRES. + */ + enum class OrthogonalizationStrategy + { + /** + * Use modified Gram-Schmidt algorithm. + */ + modified_gram_schmidt, + /** + * Use classical Gram-Schmidt algorithm. Since this approach works on + * multi-vectors with a single global reduction (of multiple elements), it + * is more efficient than the modified Gram-Schmidt algorithm. However, it + * is less stable in terms of roundoff error propagation, requiring + * additional re-orthogonalization steps more frequently. + */ + classical_gram_schmidt + }; +} // namespace LinearAlgebra + + +DEAL_II_NAMESPACE_CLOSE + +#endif diff --git a/include/deal.II/lac/solver_gmres.h b/include/deal.II/lac/solver_gmres.h index 54d2393af1..bdeb3884c9 100644 --- a/include/deal.II/lac/solver_gmres.h +++ b/include/deal.II/lac/solver_gmres.h @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -198,21 +199,6 @@ public: */ struct AdditionalData { - enum class OrthogonalizationStrategy - { - /** - * Use modified Gram-Schmidt algorithm. - */ - modified_gram_schmidt, - /** - * Use classical Gram-Schmidt algorithm. Since this approach works on - * multi-vectors and performs a global reduction only once, it is - * more efficient than the modified Gram-Schmidt algorithm. - * However, it might be numerically unstable. - */ - classical_gram_schmidt - }; - /** * Constructor. By default, set the number of temporary vectors to 30, * i.e. do a restart every 28 iterations. Also set preconditioning from @@ -221,13 +207,14 @@ public: * reduced functionality to track information is disabled by default. */ explicit AdditionalData( - const unsigned int max_n_tmp_vectors = 30, - const bool right_preconditioning = false, - const bool use_default_residual = true, - const bool force_re_orthogonalization = false, - const bool batched_mode = false, - const OrthogonalizationStrategy orthogonalization_strategy = - OrthogonalizationStrategy::modified_gram_schmidt); + const unsigned int max_n_tmp_vectors = 30, + const bool right_preconditioning = false, + const bool use_default_residual = true, + const bool force_re_orthogonalization = false, + const bool batched_mode = false, + const LinearAlgebra::OrthogonalizationStrategy + orthogonalization_strategy = + LinearAlgebra::OrthogonalizationStrategy::modified_gram_schmidt); /** * Maximum number of temporary vectors. This parameter controls the size @@ -270,7 +257,7 @@ public: /** * Strategy to orthogonalize vectors. */ - OrthogonalizationStrategy orthogonalization_strategy; + LinearAlgebra::OrthogonalizationStrategy orthogonalization_strategy; }; /** @@ -520,14 +507,24 @@ public: /** * Constructor. By default, set the maximum basis size to 30. */ - explicit AdditionalData(const unsigned int max_basis_size = 30) + explicit AdditionalData( + const unsigned int max_basis_size = 30, + const LinearAlgebra::OrthogonalizationStrategy + orthogonalization_strategy = + LinearAlgebra::OrthogonalizationStrategy::modified_gram_schmidt) : max_basis_size(max_basis_size) + , orthogonalization_strategy(orthogonalization_strategy) {} /** * Maximum basis size. */ unsigned int max_basis_size; + + /** + * Strategy to orthogonalize vectors. + */ + LinearAlgebra::OrthogonalizationStrategy orthogonalization_strategy; }; /** @@ -659,12 +656,12 @@ namespace internal template inline SolverGMRES::AdditionalData::AdditionalData( - const unsigned int max_n_tmp_vectors, - const bool right_preconditioning, - const bool use_default_residual, - const bool force_re_orthogonalization, - const bool batched_mode, - const OrthogonalizationStrategy orthogonalization_strategy) + const unsigned int max_n_tmp_vectors, + const bool right_preconditioning, + const bool use_default_residual, + const bool force_re_orthogonalization, + const bool batched_mode, + const LinearAlgebra::OrthogonalizationStrategy orthogonalization_strategy) : max_n_tmp_vectors(max_n_tmp_vectors) , right_preconditioning(right_preconditioning) , use_default_residual(use_default_residual) @@ -1133,8 +1130,7 @@ namespace internal template inline double iterated_gram_schmidt( - const typename SolverGMRES::AdditionalData:: - OrthogonalizationStrategy orthogonalization_strategy, + const LinearAlgebra::OrthogonalizationStrategy orthogonalization_strategy, const internal::SolverGMRESImplementation::TmpVectors & orthogonal_vectors, const unsigned int dim, @@ -1165,8 +1161,7 @@ namespace internal double norm_vv = 0.0; if (orthogonalization_strategy == - SolverGMRES::AdditionalData:: - OrthogonalizationStrategy::modified_gram_schmidt) + LinearAlgebra::OrthogonalizationStrategy::modified_gram_schmidt) { double htmp = vv * orthogonal_vectors[0]; h(0) += htmp; @@ -1182,8 +1177,8 @@ namespace internal vv.add_and_dot(-htmp, orthogonal_vectors[dim - 1], vv)); } else if (orthogonalization_strategy == - SolverGMRES::AdditionalData:: - OrthogonalizationStrategy::classical_gram_schmidt) + LinearAlgebra::OrthogonalizationStrategy:: + classical_gram_schmidt) { Tvmult_add(dim, vv, orthogonal_vectors, h); norm_vv = substract_and_norm(dim, orthogonal_vectors, h, vv); @@ -1778,8 +1773,7 @@ SolverFGMRES::solve(const MatrixType & A, bool re_orthogonalize = false; const double s = internal::SolverGMRESImplementation::iterated_gram_schmidt< - VectorType>(SolverGMRES::AdditionalData:: - OrthogonalizationStrategy::modified_gram_schmidt, + VectorType>(additional_data.orthogonalization_strategy, v, j + 1, 0, diff --git a/tests/lac/solver.cc b/tests/lac/solver.cc index 0ddfc6c3d3..ff81c85d8d 100644 --- a/tests/lac/solver.cc +++ b/tests/lac/solver.cc @@ -101,8 +101,8 @@ main() SolverFIRE<> fire(control, mem); SolverGMRES<>::AdditionalData data3(8); - data3.orthogonalization_strategy = SolverGMRES<>::AdditionalData:: - OrthogonalizationStrategy::classical_gram_schmidt; + data3.orthogonalization_strategy = + LinearAlgebra::OrthogonalizationStrategy::classical_gram_schmidt; SolverGMRES<> gmresclassical(control, mem, data3); for (unsigned int size = 4; size <= 30; size *= 3) diff --git a/tests/lac/solver_gmres_01.cc b/tests/lac/solver_gmres_01.cc index fb7ccad966..a79f12e0f2 100644 --- a/tests/lac/solver_gmres_01.cc +++ b/tests/lac/solver_gmres_01.cc @@ -14,7 +14,7 @@ // --------------------------------------------------------------------- // Check the path of SolverGMRES with distributed vectors and -// OrthogonalizationStrategy::classical_gram_schmidt. +// LinearAlgebra::OrthogonalizationStrategy::classical_gram_schmidt. #include @@ -108,8 +108,7 @@ main() SolverGMRES>::AdditionalData data3(8); data3.orthogonalization_strategy = - SolverGMRES>::AdditionalData:: - OrthogonalizationStrategy::classical_gram_schmidt; + LinearAlgebra::OrthogonalizationStrategy::classical_gram_schmidt; SolverGMRES> solver(control, data3); solver.connect(&monitor_norm); @@ -131,8 +130,7 @@ main() SolverGMRES>::AdditionalData data3(8); data3.orthogonalization_strategy = - SolverGMRES>:: - AdditionalData::OrthogonalizationStrategy::classical_gram_schmidt; + LinearAlgebra::OrthogonalizationStrategy::classical_gram_schmidt; SolverGMRES> solver(control, data3); solver.connect(&monitor_norm_block);