xref: /libCEED/examples/petsc/bpssphere.c (revision 5cd6c1fb67d52eb6a42b887bb79c183682dd86ca)
1 // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED:  http://github.com/ceed
7 
8 //                        libCEED + PETSc Example: CEED BPs
9 //
10 // This example demonstrates a simple usage of libCEED with PETSc to solve the CEED BP benchmark problems, see http://ceed.exascaleproject.org/bps, on
11 // a closed surface, such as the one of a discrete sphere.
12 //
13 // The code uses higher level communication protocols in DMPlex.
14 //
15 // Build with:
16 //
17 //     make bpssphere [PETSC_DIR=</path/to/petsc>] [CEED_DIR=</path/to/libceed>]
18 //
19 // Sample runs:
20 //
21 //     bpssphere -problem bp1 -degree 3
22 //     bpssphere -problem bp2 -degree 3
23 //     bpssphere -problem bp3 -degree 3
24 //     bpssphere -problem bp4 -degree 3
25 //     bpssphere -problem bp5 -degree 3 -ceed /cpu/self
26 //     bpssphere -problem bp6 -degree 3 -ceed /gpu/cuda
27 //
28 //TESTARGS -ceed {ceed_resource} -test -problem bp3 -degree 3 -dm_refine 2
29 
30 /// @file
31 /// CEED BPs example using PETSc with DMPlex
32 /// See bps.c for a "raw" implementation using a structured grid and bpsdmplex.c for an implementation using an unstructured grid.
33 static const char help[] = "Solve CEED BPs on a sphere using DMPlex in PETSc\n";
34 
35 #include "bpssphere.h"
36 
37 #include <ceed.h>
38 #include <petscdmplex.h>
39 #include <petscksp.h>
40 #include <stdbool.h>
41 #include <string.h>
42 
43 #include "include/libceedsetup.h"
44 #include "include/matops.h"
45 #include "include/petscutils.h"
46 #include "include/petscversion.h"
47 #include "include/sphereproblemdata.h"
48 
49 int main(int argc, char **argv) {
50   MPI_Comm             comm;
51   char                 ceed_resource[PETSC_MAX_PATH_LEN] = "/cpu/self", filename[PETSC_MAX_PATH_LEN];
52   double               my_rt_start, my_rt, rt_min, rt_max;
53   PetscInt             degree = 3, q_extra, l_size, g_size, topo_dim = 2, num_comp_x = 3, num_comp_u = 1, xl_size;
54   PetscScalar         *r;
55   PetscBool            test_mode, benchmark_mode, read_mesh, write_solution, simplex;
56   PetscLogStage        solve_stage;
57   Vec                  X, X_loc, rhs, rhs_loc;
58   Mat                  mat_O;
59   KSP                  ksp;
60   DM                   dm;
61   OperatorApplyContext op_apply_ctx, op_error_ctx;
62   Ceed                 ceed;
63   CeedData             ceed_data;
64   CeedQFunction        qf_error;
65   CeedOperator         op_error;
66   CeedVector           rhs_ceed, target;
67   BPType               bp_choice;
68   VecType              vec_type;
69   PetscMemType         mem_type;
70 
71   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
72   comm = PETSC_COMM_WORLD;
73 
74   // Read command line options
75   PetscOptionsBegin(comm, NULL, "CEED BPs in PETSc", NULL);
76   bp_choice = CEED_BP1;
77   PetscCall(PetscOptionsEnum("-problem", "CEED benchmark problem to solve", NULL, bp_types, (PetscEnum)bp_choice, (PetscEnum *)&bp_choice, NULL));
78   num_comp_u = bp_options[bp_choice].num_comp_u;
79   test_mode  = PETSC_FALSE;
80   PetscCall(PetscOptionsBool("-test", "Testing mode (do not print unless error is large)", NULL, test_mode, &test_mode, NULL));
81   benchmark_mode = PETSC_FALSE;
82   PetscCall(PetscOptionsBool("-benchmark", "Benchmarking mode (prints benchmark statistics)", NULL, benchmark_mode, &benchmark_mode, NULL));
83   write_solution = PETSC_FALSE;
84   PetscCall(PetscOptionsBool("-write_solution", "Write solution for visualization", NULL, write_solution, &write_solution, NULL));
85   degree = test_mode ? 3 : 2;
86   PetscCall(PetscOptionsInt("-degree", "Polynomial degree of tensor product basis", NULL, degree, &degree, NULL));
87   q_extra = bp_options[bp_choice].q_extra;
88   PetscCall(PetscOptionsInt("-q_extra", "Number of extra quadrature points", NULL, q_extra, &q_extra, NULL));
89   PetscCall(PetscOptionsString("-ceed", "CEED resource specifier", NULL, ceed_resource, ceed_resource, sizeof(ceed_resource), NULL));
90   read_mesh = PETSC_FALSE;
91   PetscCall(PetscOptionsString("-mesh", "Read mesh from file", NULL, filename, filename, sizeof(filename), &read_mesh));
92   simplex = PETSC_FALSE;
93   PetscCall(PetscOptionsBool("-simplex", "Use simplices, or tensor product cells", NULL, simplex, &simplex, NULL));
94   PetscOptionsEnd();
95 
96   // Setup DM
97   if (read_mesh) {
98     PetscCall(DMPlexCreateFromFile(PETSC_COMM_WORLD, filename, NULL, PETSC_TRUE, &dm));
99   } else {
100     // Create the mesh as a 0-refined sphere.
101     // This will create a cubic surface, not a box, and will snap to the unit sphere upon refinement.
102     PetscCall(DMPlexCreateSphereMesh(PETSC_COMM_WORLD, topo_dim, simplex, 1., &dm));
103     // Set the object name
104     PetscCall(PetscObjectSetName((PetscObject)dm, "Sphere"));
105     // Refine DMPlex with uniform refinement using runtime option -dm_refine
106     PetscCall(DMPlexSetRefinementUniform(dm, PETSC_TRUE));
107   }
108   PetscCall(DMSetFromOptions(dm));
109   // View DMPlex via runtime option
110   PetscCall(DMViewFromOptions(dm, NULL, "-dm_view"));
111 
112   // Create DM
113   PetscCall(SetupDMByDegree(dm, degree, q_extra, num_comp_u, topo_dim, false));
114 
115   // Create vectors
116   PetscCall(DMCreateGlobalVector(dm, &X));
117   PetscCall(VecGetLocalSize(X, &l_size));
118   PetscCall(VecGetSize(X, &g_size));
119   PetscCall(DMCreateLocalVector(dm, &X_loc));
120   PetscCall(VecGetSize(X_loc, &xl_size));
121   PetscCall(VecDuplicate(X, &rhs));
122 
123   // Operator
124   PetscCall(PetscMalloc1(1, &op_apply_ctx));
125   PetscCall(PetscMalloc1(1, &op_error_ctx));
126   PetscCall(MatCreateShell(comm, l_size, l_size, g_size, g_size, op_apply_ctx, &mat_O));
127   PetscCall(MatShellSetOperation(mat_O, MATOP_MULT, (void (*)(void))MatMult_Ceed));
128 
129   // Set up libCEED
130   CeedInit(ceed_resource, &ceed);
131   CeedMemType mem_type_backend;
132   CeedGetPreferredMemType(ceed, &mem_type_backend);
133 
134   PetscCall(DMGetVecType(dm, &vec_type));
135   if (!vec_type) {  // Not yet set by user -dm_vec_type
136     switch (mem_type_backend) {
137       case CEED_MEM_HOST:
138         vec_type = VECSTANDARD;
139         break;
140       case CEED_MEM_DEVICE: {
141         const char *resolved;
142         CeedGetResource(ceed, &resolved);
143         if (strstr(resolved, "/gpu/cuda")) vec_type = VECCUDA;
144         else if (strstr(resolved, "/gpu/hip/occa")) vec_type = VECSTANDARD;  // https://github.com/CEED/libCEED/issues/678
145         else if (strstr(resolved, "/gpu/hip")) vec_type = VECHIP;
146         else vec_type = VECSTANDARD;
147       }
148     }
149     PetscCall(DMSetVecType(dm, vec_type));
150   }
151 
152   // Print summary
153   if (!test_mode) {
154     PetscInt    P = degree + 1, Q = P + q_extra;
155     const char *used_resource;
156     CeedGetResource(ceed, &used_resource);
157     PetscCall(PetscPrintf(comm,
158                           "\n-- CEED Benchmark Problem %" CeedInt_FMT " on the Sphere -- libCEED + PETSc --\n"
159                           "  libCEED:\n"
160                           "    libCEED Backend                         : %s\n"
161                           "    libCEED Backend MemType                 : %s\n"
162                           "  Mesh:\n"
163                           "    Solution Order (P)                      : %" CeedInt_FMT "\n"
164                           "    Quadrature  Order (Q)                   : %" CeedInt_FMT "\n"
165                           "    Additional quadrature points (q_extra)  : %" CeedInt_FMT "\n"
166                           "    Global nodes                            : %" PetscInt_FMT "\n",
167                           bp_choice + 1, ceed_resource, CeedMemTypes[mem_type_backend], P, Q, q_extra, g_size / num_comp_u));
168   }
169 
170   // Create RHS vector
171   PetscCall(VecDuplicate(X_loc, &rhs_loc));
172   PetscCall(VecZeroEntries(rhs_loc));
173   PetscCall(VecGetArrayAndMemType(rhs_loc, &r, &mem_type));
174   CeedVectorCreate(ceed, xl_size, &rhs_ceed);
175   CeedVectorSetArray(rhs_ceed, MemTypeP2C(mem_type), CEED_USE_POINTER, r);
176 
177   // Setup libCEED's objects
178   PetscCall(PetscMalloc1(1, &ceed_data));
179   PetscCall(SetupLibceedByDegree(dm, ceed, degree, topo_dim, q_extra, num_comp_x, num_comp_u, g_size, xl_size, bp_options[bp_choice], ceed_data, true,
180                                  rhs_ceed, &target));
181 
182   // Gather RHS
183   CeedVectorTakeArray(rhs_ceed, MemTypeP2C(mem_type), NULL);
184   PetscCall(VecRestoreArrayAndMemType(rhs_loc, &r));
185   PetscCall(VecZeroEntries(rhs));
186   PetscCall(DMLocalToGlobal(dm, rhs_loc, ADD_VALUES, rhs));
187   CeedVectorDestroy(&rhs_ceed);
188 
189   // Create the error Q-function
190   CeedQFunctionCreateInterior(ceed, 1, bp_options[bp_choice].error, bp_options[bp_choice].error_loc, &qf_error);
191   CeedQFunctionAddInput(qf_error, "u", num_comp_u, CEED_EVAL_INTERP);
192   CeedQFunctionAddInput(qf_error, "true_soln", num_comp_u, CEED_EVAL_NONE);
193   CeedQFunctionAddInput(qf_error, "qdata", ceed_data->q_data_size, CEED_EVAL_NONE);
194   CeedQFunctionAddOutput(qf_error, "error", num_comp_u, CEED_EVAL_INTERP);
195 
196   // Create the error operator
197   CeedOperatorCreate(ceed, qf_error, NULL, NULL, &op_error);
198   CeedOperatorSetField(op_error, "u", ceed_data->elem_restr_u, ceed_data->basis_u, CEED_VECTOR_ACTIVE);
199   CeedOperatorSetField(op_error, "true_soln", ceed_data->elem_restr_u_i, CEED_BASIS_NONE, target);
200   CeedOperatorSetField(op_error, "qdata", ceed_data->elem_restr_qd_i, CEED_BASIS_NONE, ceed_data->q_data);
201   CeedOperatorSetField(op_error, "error", ceed_data->elem_restr_u, ceed_data->basis_u, CEED_VECTOR_ACTIVE);
202 
203   // Set up apply operator context
204   PetscCall(SetupApplyOperatorCtx(comm, dm, ceed, ceed_data, X_loc, op_apply_ctx));
205 
206   // Setup solver
207   PetscCall(KSPCreate(comm, &ksp));
208   {
209     PC pc;
210     PetscCall(KSPGetPC(ksp, &pc));
211     if (bp_choice == CEED_BP1 || bp_choice == CEED_BP2) {
212       PetscCall(PCSetType(pc, PCJACOBI));
213       PetscCall(PCJacobiSetType(pc, PC_JACOBI_ROWSUM));
214     } else {
215       PetscCall(PCSetType(pc, PCNONE));
216       MatNullSpace nullspace;
217 
218       PetscCall(MatNullSpaceCreate(PETSC_COMM_WORLD, PETSC_TRUE, 0, 0, &nullspace));
219       PetscCall(MatSetNullSpace(mat_O, nullspace));
220       PetscCall(MatNullSpaceDestroy(&nullspace));
221     }
222     PetscCall(KSPSetType(ksp, KSPCG));
223     PetscCall(KSPSetNormType(ksp, KSP_NORM_NATURAL));
224     PetscCall(KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
225   }
226   PetscCall(KSPSetFromOptions(ksp));
227   PetscCall(KSPSetOperators(ksp, mat_O, mat_O));
228 
229   // First run, if benchmarking
230   if (benchmark_mode) {
231     PetscCall(KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 1));
232     my_rt_start = MPI_Wtime();
233     PetscCall(KSPSolve(ksp, rhs, X));
234     my_rt = MPI_Wtime() - my_rt_start;
235     PetscCall(MPI_Allreduce(MPI_IN_PLACE, &my_rt, 1, MPI_DOUBLE, MPI_MIN, comm));
236     // Set maxits based on first iteration timing
237     if (my_rt > 0.02) {
238       PetscCall(KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 5));
239     } else {
240       PetscCall(KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 20));
241     }
242   }
243 
244   // Timed solve
245   PetscCall(VecZeroEntries(X));
246   PetscCall(PetscBarrier((PetscObject)ksp));
247 
248   // -- Performance logging
249   PetscCall(PetscLogStageRegister("Solve Stage", &solve_stage));
250   PetscCall(PetscLogStagePush(solve_stage));
251 
252   // -- Solve
253   my_rt_start = MPI_Wtime();
254   PetscCall(KSPSolve(ksp, rhs, X));
255   my_rt = MPI_Wtime() - my_rt_start;
256 
257   // -- Performance logging
258   PetscCall(PetscLogStagePop());
259 
260   // Output results
261   {
262     KSPType            ksp_type;
263     KSPConvergedReason reason;
264     PetscReal          rnorm;
265     PetscInt           its;
266     PetscCall(KSPGetType(ksp, &ksp_type));
267     PetscCall(KSPGetConvergedReason(ksp, &reason));
268     PetscCall(KSPGetIterationNumber(ksp, &its));
269     PetscCall(KSPGetResidualNorm(ksp, &rnorm));
270     if (!test_mode || reason < 0 || rnorm > 1e-8) {
271       PetscCall(PetscPrintf(comm,
272                             "  KSP:\n"
273                             "    KSP Type                                : %s\n"
274                             "    KSP Convergence                         : %s\n"
275                             "    Total KSP Iterations                    : %" PetscInt_FMT "\n"
276                             "    Final rnorm                             : %e\n",
277                             ksp_type, KSPConvergedReasons[reason], its, (double)rnorm));
278     }
279     if (!test_mode) {
280       PetscCall(PetscPrintf(comm, "  Performance:\n"));
281     }
282     {
283       // Set up error operator context
284       PetscCall(SetupErrorOperatorCtx(comm, dm, ceed, ceed_data, X_loc, op_error, op_error_ctx));
285       PetscScalar l2_error;
286       PetscCall(ComputeL2Error(X, &l2_error, op_error_ctx));
287       PetscReal tol = 5e-4;
288       if (!test_mode || l2_error > tol) {
289         PetscCall(MPI_Allreduce(&my_rt, &rt_min, 1, MPI_DOUBLE, MPI_MIN, comm));
290         PetscCall(MPI_Allreduce(&my_rt, &rt_max, 1, MPI_DOUBLE, MPI_MAX, comm));
291         PetscCall(PetscPrintf(comm,
292                               "    L2 Error                                : %e\n"
293                               "    CG Solve Time                           : %g (%g) sec\n",
294                               (double)l2_error, rt_max, rt_min));
295       }
296     }
297     if (benchmark_mode && (!test_mode)) {
298       PetscCall(PetscPrintf(comm, "    DoFs/Sec in CG                            : %g (%g) million\n", 1e-6 * g_size * its / rt_max,
299                             1e-6 * g_size * its / rt_min));
300     }
301   }
302 
303   // Output solution
304   if (write_solution) {
305     PetscViewer vtk_viewer_soln;
306 
307     PetscCall(PetscViewerCreate(comm, &vtk_viewer_soln));
308     PetscCall(PetscViewerSetType(vtk_viewer_soln, PETSCVIEWERVTK));
309     PetscCall(PetscViewerFileSetName(vtk_viewer_soln, "solution.vtu"));
310     PetscCall(VecView(X, vtk_viewer_soln));
311     PetscCall(PetscViewerDestroy(&vtk_viewer_soln));
312   }
313 
314   // Cleanup
315   PetscCall(VecDestroy(&X));
316   PetscCall(VecDestroy(&X_loc));
317   PetscCall(VecDestroy(&op_apply_ctx->Y_loc));
318   PetscCall(VecDestroy(&op_error_ctx->Y_loc));
319   PetscCall(MatDestroy(&mat_O));
320   PetscCall(PetscFree(op_apply_ctx));
321   PetscCall(PetscFree(op_error_ctx));
322   PetscCall(CeedDataDestroy(0, ceed_data));
323   PetscCall(DMDestroy(&dm));
324 
325   PetscCall(VecDestroy(&rhs));
326   PetscCall(VecDestroy(&rhs_loc));
327   PetscCall(KSPDestroy(&ksp));
328   CeedVectorDestroy(&target);
329   CeedQFunctionDestroy(&qf_error);
330   CeedOperatorDestroy(&op_error);
331   CeedDestroy(&ceed);
332   return PetscFinalize();
333 }
334