From 6c98a63a0eca1d0abbc700bdd5a43bbf2d0737f9 Mon Sep 17 00:00:00 2001
From: Christoph Lehmann <christoph.lehmann@ufz.de>
Date: Sat, 16 Sep 2023 11:18:13 +0200
Subject: [PATCH] [NL] Picard: Linear solver computes only if necessary
---
NumLib/ODESolver/NonlinearSolver.cpp | 73 ++++++++++++++++++++++++----
1 file changed, 64 insertions(+), 9 deletions(-)
diff --git a/NumLib/ODESolver/NonlinearSolver.cpp b/NumLib/ODESolver/NonlinearSolver.cpp
index 29b4e69ffeb..1e57a38f1ea 100644
--- a/NumLib/ODESolver/NonlinearSolver.cpp
+++ b/NumLib/ODESolver/NonlinearSolver.cpp
@@ -24,6 +24,67 @@
namespace NumLib
{
+namespace detail
+{
+#if !defined(USE_PETSC) && !defined(USE_LIS)
+bool solvePicard(GlobalLinearSolver& linear_solver, GlobalMatrix& A,
+ GlobalVector& rhs, GlobalVector& x,
+ bool const compute_necessary)
+{
+ BaseLib::RunTime time_linear_solver;
+ time_linear_solver.start();
+
+ if (compute_necessary)
+ {
+ if (!linear_solver.compute(A))
+ {
+ ERR("Picard: The linear solver failed in the compute() step.");
+ return false;
+ }
+ }
+
+ bool const iteration_succeeded = linear_solver.solve(rhs, x);
+
+ INFO("[time] Linear solver took {:g} s.", time_linear_solver.elapsed());
+
+ if (iteration_succeeded)
+ {
+ return true;
+ }
+
+ ERR("Picard: The linear solver failed in the solve() step.");
+ return false;
+}
+#else
+bool solvePicard(GlobalLinearSolver& linear_solver, GlobalMatrix& A,
+ GlobalVector& rhs, GlobalVector& x,
+ bool const compute_necessary)
+{
+ if (!compute_necessary)
+ {
+ WARN(
+ "The performance optimization to skip the linear solver compute() "
+ "step is not implemented for PETSc or LIS linear solvers.");
+ }
+
+ BaseLib::RunTime time_linear_solver;
+ time_linear_solver.start();
+
+ bool const iteration_succeeded = linear_solver.solve(A, rhs, x);
+
+ INFO("[time] Linear solver took {:g} s.", time_linear_solver.elapsed());
+
+ if (iteration_succeeded)
+ {
+ return true;
+ }
+
+ ERR("Picard: The linear solver failed in the solve() step.");
+ return false;
+}
+#endif
+} // namespace detail
+
void NonlinearSolver<NonlinearSolverTag::Picard>::
calculateNonEquilibriumInitialResiduum(
std::vector<GlobalVector*> const& x,
@@ -128,17 +189,11 @@ NonlinearSolverStatus NonlinearSolver<NonlinearSolverTag::Picard>::solve(
_convergence_criterion->checkResidual(res);
}
- BaseLib::RunTime time_linear_solver;
- time_linear_solver.start();
bool iteration_succeeded =
- _linear_solver.solve(A, rhs, *x_new[process_id]);
- INFO("[time] Linear solver took {:g} s.", time_linear_solver.elapsed());
+ detail::solvePicard(_linear_solver, A, rhs, x_new_process,
+ sys.linearSolverNeedsToCompute());
- if (!iteration_succeeded)
- {
- ERR("Picard: The linear solver failed.");
- }
- else
+ if (iteration_succeeded)
{
if (postIterationCallback)
{
--
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