1 static char help[] = "Benchmark Poisson Problem in 2d and 3d with finite elements.\n\ 2 We solve the Poisson problem in a rectangular domain\n\ 3 using a parallel unstructured mesh (DMPLEX) to discretize it.\n\n\n"; 4 5 #include <petscdmplex.h> 6 #include <petscsnes.h> 7 #include <petscds.h> 8 #include <petscconvest.h> 9 #if defined(PETSC_HAVE_AMGX) 10 #include <amgx_c.h> 11 #endif 12 13 typedef struct { 14 PetscInt nit; /* Number of benchmark iterations */ 15 PetscBool strong; /* Do not integrate the Laplacian by parts */ 16 } AppCtx; 17 18 static PetscErrorCode trig_u(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx) 19 { 20 PetscInt d; 21 *u = 0.0; 22 for (d = 0; d < dim; ++d) *u += PetscSinReal(2.0 * PETSC_PI * x[d]); 23 return 0; 24 } 25 26 static void f0_trig_u(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[]) 27 { 28 PetscInt d; 29 for (d = 0; d < dim; ++d) f0[0] += -4.0 * PetscSqr(PETSC_PI) * PetscSinReal(2.0 * PETSC_PI * x[d]); 30 } 31 32 static void f1_u(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[]) 33 { 34 PetscInt d; 35 for (d = 0; d < dim; ++d) f1[d] = u_x[d]; 36 } 37 38 static void g3_uu(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, PetscReal u_tShift, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar g3[]) 39 { 40 PetscInt d; 41 for (d = 0; d < dim; ++d) g3[d * dim + d] = 1.0; 42 } 43 44 static PetscErrorCode quadratic_u(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx) 45 { 46 *u = PetscSqr(x[0]) + PetscSqr(x[1]); 47 return 0; 48 } 49 50 static void f0_strong_u(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[]) 51 { 52 PetscInt d; 53 for (d = 0; d < dim; ++d) f0[0] -= u_x[dim + d * dim + d]; 54 f0[0] += 4.0; 55 } 56 57 static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options) 58 { 59 PetscFunctionBeginUser; 60 options->nit = 10; 61 options->strong = PETSC_FALSE; 62 PetscOptionsBegin(comm, "", "Poisson Problem Options", "DMPLEX"); 63 PetscCall(PetscOptionsInt("-benchmark_it", "Solve the benchmark problem this many times", "ex13.c", options->nit, &options->nit, NULL)); 64 PetscCall(PetscOptionsBool("-strong", "Do not integrate the Laplacian by parts", "ex13.c", options->strong, &options->strong, NULL)); 65 PetscOptionsEnd(); 66 PetscFunctionReturn(0); 67 } 68 69 static PetscErrorCode CreateMesh(MPI_Comm comm, AppCtx *user, DM *dm) 70 { 71 PetscFunctionBeginUser; 72 PetscCall(DMCreate(comm, dm)); 73 PetscCall(DMSetType(*dm, DMPLEX)); 74 PetscCall(DMSetFromOptions(*dm)); 75 PetscCall(DMSetApplicationContext(*dm, user)); 76 PetscCall(DMViewFromOptions(*dm, NULL, "-dm_view")); 77 PetscFunctionReturn(0); 78 } 79 80 static PetscErrorCode SetupPrimalProblem(DM dm, AppCtx *user) 81 { 82 PetscDS ds; 83 DMLabel label; 84 const PetscInt id = 1; 85 86 PetscFunctionBeginUser; 87 PetscCall(DMGetDS(dm, &ds)); 88 PetscCall(DMGetLabel(dm, "marker", &label)); 89 if (user->strong) { 90 PetscCall(PetscDSSetResidual(ds, 0, f0_strong_u, NULL)); 91 PetscCall(PetscDSSetExactSolution(ds, 0, quadratic_u, user)); 92 PetscCall(DMAddBoundary(dm, DM_BC_ESSENTIAL, "wall", label, 1, &id, 0, 0, NULL, (void (*)(void))quadratic_u, NULL, user, NULL)); 93 } else { 94 PetscCall(PetscDSSetResidual(ds, 0, f0_trig_u, f1_u)); 95 PetscCall(PetscDSSetJacobian(ds, 0, 0, NULL, NULL, NULL, g3_uu)); 96 PetscCall(PetscDSSetExactSolution(ds, 0, trig_u, user)); 97 PetscCall(DMAddBoundary(dm, DM_BC_ESSENTIAL, "wall", label, 1, &id, 0, 0, NULL, (void (*)(void))trig_u, NULL, user, NULL)); 98 } 99 PetscFunctionReturn(0); 100 } 101 102 static PetscErrorCode SetupDiscretization(DM dm, const char name[], PetscErrorCode (*setup)(DM, AppCtx *), AppCtx *user) 103 { 104 DM cdm = dm; 105 PetscFE fe; 106 DMPolytopeType ct; 107 PetscBool simplex; 108 PetscInt dim, cStart; 109 char prefix[PETSC_MAX_PATH_LEN]; 110 111 PetscFunctionBeginUser; 112 PetscCall(DMGetDimension(dm, &dim)); 113 PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL)); 114 PetscCall(DMPlexGetCellType(dm, cStart, &ct)); 115 simplex = DMPolytopeTypeGetNumVertices(ct) == DMPolytopeTypeGetDim(ct) + 1 ? PETSC_TRUE : PETSC_FALSE; // false 116 /* Create finite element */ 117 PetscCall(PetscSNPrintf(prefix, PETSC_MAX_PATH_LEN, "%s_", name)); 118 PetscCall(PetscFECreateDefault(PETSC_COMM_SELF, dim, 1, simplex, name ? prefix : NULL, -1, &fe)); 119 PetscCall(PetscObjectSetName((PetscObject)fe, name)); 120 /* Set discretization and boundary conditions for each mesh */ 121 PetscCall(DMSetField(dm, 0, NULL, (PetscObject)fe)); 122 PetscCall(DMCreateDS(dm)); 123 PetscCall((*setup)(dm, user)); 124 while (cdm) { 125 PetscCall(DMCopyDisc(dm, cdm)); 126 /* TODO: Check whether the boundary of coarse meshes is marked */ 127 PetscCall(DMGetCoarseDM(cdm, &cdm)); 128 } 129 PetscCall(PetscFEDestroy(&fe)); 130 PetscFunctionReturn(0); 131 } 132 133 int main(int argc, char **argv) 134 { 135 DM dm; /* Problem specification */ 136 SNES snes; /* Nonlinear solver */ 137 Vec u; /* Solutions */ 138 AppCtx user; /* User-defined work context */ 139 PetscLogDouble time; 140 Mat Amat; 141 142 PetscFunctionBeginUser; 143 PetscCall(PetscInitialize(&argc, &argv, NULL, help)); 144 PetscCall(ProcessOptions(PETSC_COMM_WORLD, &user)); 145 /* system */ 146 PetscCall(SNESCreate(PETSC_COMM_WORLD, &snes)); 147 PetscCall(CreateMesh(PETSC_COMM_WORLD, &user, &dm)); 148 PetscCall(SNESSetDM(snes, dm)); 149 PetscCall(SetupDiscretization(dm, "potential", SetupPrimalProblem, &user)); 150 PetscCall(DMCreateGlobalVector(dm, &u)); 151 { 152 PetscInt N; 153 PetscCall(VecGetSize(u, &N)); 154 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Number equations N = %" PetscInt_FMT "\n", N)); 155 } 156 PetscCall(SNESSetFromOptions(snes)); 157 PetscCall(PetscObjectSetName((PetscObject)u, "potential")); 158 PetscCall(DMPlexSetSNESLocalFEM(dm, &user, &user, &user)); 159 PetscCall(DMSNESCheckFromOptions(snes, u)); 160 PetscCall(PetscTime(&time)); 161 PetscCall(SNESSetUp(snes)); 162 #if defined(PETSC_HAVE_AMGX) 163 KSP ksp; 164 PC pc; 165 PetscBool flg; 166 AMGX_resources_handle rsc; 167 PetscCall(SNESGetKSP(snes, &ksp)); 168 PetscCall(KSPGetPC(ksp, &pc)); 169 PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCAMGX, &flg)); 170 if (flg) { 171 PetscCall(PCAmgXGetResources(pc, (void *)&rsc)); 172 /* do ... with resource */ 173 } 174 #endif 175 PetscCall(SNESGetJacobian(snes, &Amat, NULL, NULL, NULL)); 176 PetscCall(MatSetOption(Amat, MAT_SPD, PETSC_TRUE)); 177 PetscCall(MatSetOption(Amat, MAT_SPD_ETERNAL, PETSC_TRUE)); 178 PetscCall(SNESSolve(snes, NULL, u)); 179 PetscCall(PetscTimeSubtract(&time)); 180 /* Benchmark system */ 181 if (user.nit) { 182 Vec b; 183 PetscInt i; 184 #if defined(PETSC_USE_LOG) 185 PetscLogStage kspstage; 186 #endif 187 PetscCall(PetscLogStageRegister("Solve only", &kspstage)); 188 PetscCall(PetscLogStagePush(kspstage)); 189 PetscCall(SNESGetSolution(snes, &u)); 190 PetscCall(SNESGetFunction(snes, &b, NULL, NULL)); 191 for (i = 0; i < user.nit; i++) { 192 PetscCall(VecZeroEntries(u)); 193 PetscCall(SNESSolve(snes, NULL, u)); 194 } 195 PetscCall(PetscLogStagePop()); 196 } 197 PetscCall(SNESGetSolution(snes, &u)); 198 PetscCall(VecViewFromOptions(u, NULL, "-potential_view")); 199 /* Cleanup */ 200 PetscCall(VecDestroy(&u)); 201 PetscCall(SNESDestroy(&snes)); 202 PetscCall(DMDestroy(&dm)); 203 PetscCall(PetscFinalize()); 204 return 0; 205 } 206 207 /*TEST 208 209 test: 210 suffix: strong 211 requires: triangle 212 args: -dm_plex_dim 2 -dm_refine 1 -benchmark_it 0 -dmsnes_check -potential_petscspace_degree 2 -dm_ds_jet_degree 2 -strong 213 214 test: 215 suffix: bench 216 nsize: 4 217 args: -dm_plex_dim 3 -dm_plex_simplex 0 -dm_plex_box_faces 2,2,1 -dm_refine 2 -dm_view -ksp_monitor \ 218 -benchmark_it 1 -dm_plex_box_upper 2,2,1 -dm_plex_box_lower 0,0,0 -dm_plex_dim 3 -ksp_converged_reason \ 219 -ksp_norm_type unpreconditioned -ksp_rtol 1.e-6 -ksp_type cg -mg_levels_ksp_chebyshev_esteig 0,0.2,0,1.1 \ 220 -mg_levels_ksp_max_it 1 -mg_levels_ksp_type chebyshev -mg_levels_pc_type jacobi -pc_gamg_coarse_eq_limit 200 \ 221 -pc_gamg_coarse_grid_layout_type compact -pc_gamg_esteig_ksp_max_it 5 -pc_gamg_process_eq_limit 200 \ 222 -pc_gamg_repartition false -pc_gamg_reuse_interpolation true -pc_gamg_aggressive_coarsening 0 -pc_gamg_threshold 0.001 -pc_gamg_threshold_scale .5 \ 223 -pc_gamg_type agg -pc_type gamg -petscpartitioner_simple_node_grid 1,2,1 -petscpartitioner_simple_process_grid 2,1,1 \ 224 -petscpartitioner_type simple -potential_petscspace_degree 2 -snes_lag_jacobian -2 -snes_max_it 1 -snes_rtol 1.e-8 -snes_type ksponly -use_gpu_aware_mpi true 225 226 testset: 227 nsize: 4 228 output_file: output/ex13_comparison.out 229 args: -dm_plex_dim 2 -benchmark_it 10 -dm_plex_box_faces 4,4 -dm_refine 3 -petscpartitioner_simple_process_grid 2,2 \ 230 -petscpartitioner_simple_node_grid 1,1 -potential_petscspace_degree 2 -petscpartitioner_type simple \ 231 -dm_plex_simplex 0 -snes_type ksponly -dm_view -ksp_type cg -pc_type gamg -pc_gamg_process_eq_limit 400 \ 232 -ksp_norm_type unpreconditioned -ksp_converged_reason 233 test: 234 suffix: comparison 235 test: 236 suffix: cuda 237 requires: cuda 238 args: -dm_mat_type aijcusparse -dm_vec_type cuda 239 test: 240 suffix: kokkos 241 requires: sycl kokkos_kernels 242 args: -dm_mat_type aijkokkos -dm_vec_type kokkos 243 test: 244 suffix: aijmkl_comp 245 requires: mkl_sparse 246 args: -dm_mat_type aijmkl 247 248 test: 249 suffix: aijmkl_seq 250 nsize: 1 251 requires: mkl_sparse 252 TODO: broken (INDEFINITE PC) 253 args: -dm_plex_dim 3 -dm_plex_box_faces 4,4,4 -dm_refine 1 -petscpartitioner_type simple -potential_petscspace_degree 1 -dm_plex_simplex 0 \ 254 -snes_type ksponly -dm_view -pc_type gamg -pc_gamg_threshold -1 -pc_gamg_square_graph 10 -pc_gamg_process_eq_limit 400 \ 255 -pc_gamg_reuse_interpolation -pc_gamg_coarse_eq_limit 10 -pc_gamg_esteig_ksp_type cg -ksp_type cg -ksp_norm_type unpreconditioned \ 256 -ksp_converged_reason -snes_rtol 1.e-4 -dm_mat_type aijmkl -dm_vec_type standard 257 258 testset: 259 requires: cuda amgx 260 filter: grep -v Built | grep -v "AMGX version" | grep -v "CUDA Runtime" 261 output_file: output/ex13_amgx.out 262 args: -dm_plex_dim 2 -dm_plex_box_faces 2,2 -dm_refine 2 -petscpartitioner_type simple -potential_petscspace_degree 2 -dm_plex_simplex 0 -ksp_monitor \ 263 -snes_type ksponly -dm_view -ksp_type cg -ksp_norm_type unpreconditioned -ksp_converged_reason -snes_rtol 1.e-4 -pc_type amgx -benchmark_it 1 -pc_amgx_verbose false 264 nsize: 4 265 test: 266 suffix: amgx 267 args: -dm_mat_type aijcusparse -dm_vec_type cuda 268 test: 269 suffix: amgx_cpu 270 args: -dm_mat_type aij 271 272 TEST*/ 273