xref: /libCEED/examples/petsc/bpssphere.c (revision e83e87a50f1b2e8810b376a735430565127e4d25)
1 // Copyright (c) 2017, Lawrence Livermore National Security, LLC. Produced at
2 // the Lawrence Livermore National Laboratory. LLNL-CODE-734707. All Rights
3 // reserved. See files LICENSE and NOTICE for details.
4 //
5 // This file is part of CEED, a collection of benchmarks, miniapps, software
6 // libraries and APIs for efficient high-order finite element and spectral
7 // element discretizations for exascale applications. For more information and
8 // source code availability see http://github.com/ceed.
9 //
10 // The CEED research is supported by the Exascale Computing Project 17-SC-20-SC,
11 // a collaborative effort of two U.S. Department of Energy organizations (Office
12 // of Science and the National Nuclear Security Administration) responsible for
13 // the planning and preparation of a capable exascale ecosystem, including
14 // software, applications, hardware, advanced system engineering and early
15 // testbed platforms, in support of the nation's exascale computing imperative.
16 
17 //                        libCEED + PETSc Example: CEED BPs
18 //
19 // This example demonstrates a simple usage of libCEED with PETSc to solve the
20 // CEED BP benchmark problems, see http://ceed.exascaleproject.org/bps,
21 // on a closed surface, such as the one of a discrete sphere.
22 //
23 // The code uses higher level communication protocols in DMPlex.
24 //
25 // Build with:
26 //
27 //     make bpssphere [PETSC_DIR=</path/to/petsc>] [CEED_DIR=</path/to/libceed>]
28 //
29 // Sample runs:
30 //
31 //     bpssphere -problem bp1 -degree 3
32 //     bpssphere -problem bp2 -degree 3
33 //     bpssphere -problem bp3 -degree 3
34 //     bpssphere -problem bp4 -degree 3
35 //     bpssphere -problem bp5 -degree 3 -ceed /cpu/self
36 //     bpssphere -problem bp6 -degree 3 -ceed /gpu/cuda
37 //
38 //TESTARGS -ceed {ceed_resource} -test -problem bp3 -degree 3 -dm_refine 2
39 
40 /// @file
41 /// CEED BPs example using PETSc with DMPlex
42 /// See bps.c for a "raw" implementation using a structured grid.
43 /// and bpsdmplex.c for an implementation using an unstructured grid.
44 static const char help[] = "Solve CEED BPs on a sphere using DMPlex in PETSc\n";
45 
46 #include <ceed.h>
47 #include <petscdmplex.h>
48 #include <petscksp.h>
49 #include <stdbool.h>
50 #include <string.h>
51 #include "bpssphere.h"
52 
53 int main(int argc, char **argv) {
54   PetscInt ierr;
55   MPI_Comm comm;
56   char ceedresource[PETSC_MAX_PATH_LEN] = "/cpu/self",
57                                           filename[PETSC_MAX_PATH_LEN];
58   double my_rt_start, my_rt, rt_min, rt_max;
59   PetscInt degree = 3, qextra, lsize, gsize, topodim = 2, ncompx = 3,
60            ncompu = 1, xlsize;
61   PetscScalar *r;
62   PetscBool test_mode, benchmark_mode, read_mesh, write_solution, simplex;
63   PetscLogStage solvestage;
64   Vec X, Xloc, rhs, rhsloc;
65   Mat matO;
66   KSP ksp;
67   DM  dm;
68   UserO userO;
69   Ceed ceed;
70   CeedData ceeddata;
71   CeedQFunction qfError;
72   CeedOperator opError;
73   CeedVector rhsceed, target;
74   bpType bpChoice;
75   VecType vectype;
76   PetscMemType memtype;
77 
78   ierr = PetscInitialize(&argc, &argv, NULL, help);
79   if (ierr) return ierr;
80   comm = PETSC_COMM_WORLD;
81 
82   // Read command line options
83   ierr = PetscOptionsBegin(comm, NULL, "CEED BPs in PETSc", NULL); CHKERRQ(ierr);
84   bpChoice = CEED_BP1;
85   ierr = PetscOptionsEnum("-problem",
86                           "CEED benchmark problem to solve", NULL,
87                           bpTypes, (PetscEnum)bpChoice, (PetscEnum *)&bpChoice,
88                           NULL); CHKERRQ(ierr);
89   ncompu = bpOptions[bpChoice].ncompu;
90   test_mode = PETSC_FALSE;
91   ierr = PetscOptionsBool("-test",
92                           "Testing mode (do not print unless error is large)",
93                           NULL, test_mode, &test_mode, NULL); CHKERRQ(ierr);
94   benchmark_mode = PETSC_FALSE;
95   ierr = PetscOptionsBool("-benchmark",
96                           "Benchmarking mode (prints benchmark statistics)",
97                           NULL, benchmark_mode, &benchmark_mode, NULL);
98   CHKERRQ(ierr);
99   write_solution = PETSC_FALSE;
100   ierr = PetscOptionsBool("-write_solution",
101                           "Write solution for visualization",
102                           NULL, write_solution, &write_solution, NULL);
103   CHKERRQ(ierr);
104   degree = test_mode ? 3 : 2;
105   ierr = PetscOptionsInt("-degree", "Polynomial degree of tensor product basis",
106                          NULL, degree, &degree, NULL); CHKERRQ(ierr);
107   qextra = bpOptions[bpChoice].qextra;
108   ierr = PetscOptionsInt("-qextra", "Number of extra quadrature points",
109                          NULL, qextra, &qextra, NULL); CHKERRQ(ierr);
110   ierr = PetscOptionsString("-ceed", "CEED resource specifier",
111                             NULL, ceedresource, ceedresource,
112                             sizeof(ceedresource), NULL); CHKERRQ(ierr);
113   read_mesh = PETSC_FALSE;
114   ierr = PetscOptionsString("-mesh", "Read mesh from file", NULL,
115                             filename, filename, sizeof(filename), &read_mesh);
116   CHKERRQ(ierr);
117   simplex = PETSC_FALSE;
118   ierr = PetscOptionsBool("-simplex", "Use simplices, or tensor product cells",
119                           NULL, simplex, &simplex, NULL); CHKERRQ(ierr);
120   ierr = PetscOptionsEnd(); CHKERRQ(ierr);
121 
122   // Setup DM
123   if (read_mesh) {
124     ierr = DMPlexCreateFromFile(PETSC_COMM_WORLD, filename, PETSC_TRUE, &dm);
125     CHKERRQ(ierr);
126   } else {
127     // Create the mesh as a 0-refined sphere. This will create a cubic surface, not a box
128     ierr = DMPlexCreateSphereMesh(PETSC_COMM_WORLD, topodim, simplex, 1., &dm);
129     CHKERRQ(ierr);
130     // Set the object name
131     ierr = PetscObjectSetName((PetscObject)dm, "Sphere"); CHKERRQ(ierr);
132     // Distribute mesh over processes
133     {
134       DM dmDist = NULL;
135       PetscPartitioner part;
136 
137       ierr = DMPlexGetPartitioner(dm, &part); CHKERRQ(ierr);
138       ierr = PetscPartitionerSetFromOptions(part); CHKERRQ(ierr);
139       ierr = DMPlexDistribute(dm, 0, NULL, &dmDist); CHKERRQ(ierr);
140       if (dmDist) {
141         ierr = DMDestroy(&dm); CHKERRQ(ierr);
142         dm  = dmDist;
143       }
144     }
145     // Refine DMPlex with uniform refinement using runtime option -dm_refine
146     ierr = DMPlexSetRefinementUniform(dm, PETSC_TRUE); CHKERRQ(ierr);
147     ierr = DMSetFromOptions(dm); CHKERRQ(ierr);
148     ierr = ProjectToUnitSphere(dm); CHKERRQ(ierr);
149     // View DMPlex via runtime option
150     ierr = DMViewFromOptions(dm, NULL, "-dm_view"); CHKERRQ(ierr);
151   }
152 
153   // Create DM
154   ierr = SetupDMByDegree(dm, degree, ncompu, topodim, false, (BCFunction)NULL);
155   CHKERRQ(ierr);
156 
157   // Create vectors
158   ierr = DMCreateGlobalVector(dm, &X); CHKERRQ(ierr);
159   ierr = VecGetLocalSize(X, &lsize); CHKERRQ(ierr);
160   ierr = VecGetSize(X, &gsize); CHKERRQ(ierr);
161   ierr = DMCreateLocalVector(dm, &Xloc); CHKERRQ(ierr);
162   ierr = VecGetSize(Xloc, &xlsize); CHKERRQ(ierr);
163   ierr = VecDuplicate(X, &rhs); CHKERRQ(ierr);
164 
165   // Operator
166   ierr = PetscMalloc1(1, &userO); CHKERRQ(ierr);
167   ierr = MatCreateShell(comm, lsize, lsize, gsize, gsize,
168                         userO, &matO); CHKERRQ(ierr);
169   ierr = MatShellSetOperation(matO, MATOP_MULT,
170                               (void(*)(void))MatMult_Ceed); CHKERRQ(ierr);
171 
172   // Set up libCEED
173   CeedInit(ceedresource, &ceed);
174   CeedMemType memtypebackend;
175   CeedGetPreferredMemType(ceed, &memtypebackend);
176 
177   ierr = DMGetVecType(dm, &vectype); CHKERRQ(ierr);
178   if (!vectype) { // Not yet set by user -dm_vec_type
179     switch (memtypebackend) {
180     case CEED_MEM_HOST: vectype = VECSTANDARD; break;
181     case CEED_MEM_DEVICE: {
182       const char *resolved;
183       CeedGetResource(ceed, &resolved);
184       if (strstr(resolved, "/gpu/cuda")) vectype = VECCUDA;
185       else if (strstr(resolved, "/gpu/hip/occa"))
186         vectype = VECSTANDARD; // https://github.com/CEED/libCEED/issues/678
187       else if (strstr(resolved, "/gpu/hip")) vectype = VECHIP;
188       else vectype = VECSTANDARD;
189     }
190     }
191     ierr = DMSetVecType(dm, vectype); CHKERRQ(ierr);
192   }
193 
194   // Print summary
195   if (!test_mode) {
196     PetscInt P = degree + 1, Q = P + qextra;
197     const char *usedresource;
198     CeedGetResource(ceed, &usedresource);
199     ierr = PetscPrintf(comm,
200                        "\n-- CEED Benchmark Problem %d on the Sphere -- libCEED + PETSc --\n"
201                        "  libCEED:\n"
202                        "    libCEED Backend                    : %s\n"
203                        "    libCEED Backend MemType            : %s\n"
204                        "  Mesh:\n"
205                        "    Number of 1D Basis Nodes (p)       : %d\n"
206                        "    Number of 1D Quadrature Points (q) : %d\n"
207                        "    Global nodes                       : %D\n",
208                        bpChoice+1, ceedresource, CeedMemTypes[memtypebackend], P, Q,
209                        gsize/ncompu); CHKERRQ(ierr);
210   }
211 
212   // Create RHS vector
213   ierr = VecDuplicate(Xloc, &rhsloc); CHKERRQ(ierr);
214   ierr = VecZeroEntries(rhsloc); CHKERRQ(ierr);
215   ierr = VecGetArrayAndMemType(rhsloc, &r, &memtype); CHKERRQ(ierr);
216   CeedVectorCreate(ceed, xlsize, &rhsceed);
217   CeedVectorSetArray(rhsceed, MemTypeP2C(memtype), CEED_USE_POINTER, r);
218 
219   // Setup libCEED's objects
220   ierr = PetscMalloc1(1, &ceeddata); CHKERRQ(ierr);
221   ierr = SetupLibceedByDegree(dm, ceed, degree, topodim, qextra,
222                               ncompx, ncompu, gsize, xlsize, bpOptions[bpChoice],
223                               ceeddata, true, rhsceed, &target); CHKERRQ(ierr);
224 
225   // Gather RHS
226   CeedVectorTakeArray(rhsceed, MemTypeP2C(memtype), NULL);
227   ierr = VecRestoreArrayAndMemType(rhsloc, &r); CHKERRQ(ierr);
228   ierr = VecZeroEntries(rhs); CHKERRQ(ierr);
229   ierr = DMLocalToGlobal(dm, rhsloc, ADD_VALUES, rhs); CHKERRQ(ierr);
230   CeedVectorDestroy(&rhsceed);
231 
232   // Create the error Q-function
233   CeedQFunctionCreateInterior(ceed, 1, bpOptions[bpChoice].error,
234                               bpOptions[bpChoice].errorfname, &qfError);
235   CeedQFunctionAddInput(qfError, "u", ncompu, CEED_EVAL_INTERP);
236   CeedQFunctionAddInput(qfError, "true_soln", ncompu, CEED_EVAL_NONE);
237   CeedQFunctionAddOutput(qfError, "error", ncompu, CEED_EVAL_NONE);
238 
239   // Create the error operator
240   CeedOperatorCreate(ceed, qfError, NULL, NULL, &opError);
241   CeedOperatorSetField(opError, "u", ceeddata->Erestrictu,
242                        ceeddata->basisu, CEED_VECTOR_ACTIVE);
243   CeedOperatorSetField(opError, "true_soln", ceeddata->Erestrictui,
244                        CEED_BASIS_COLLOCATED, target);
245   CeedOperatorSetField(opError, "error", ceeddata->Erestrictui,
246                        CEED_BASIS_COLLOCATED, CEED_VECTOR_ACTIVE);
247 
248   // Set up Mat
249   userO->comm = comm;
250   userO->dm = dm;
251   userO->Xloc = Xloc;
252   ierr = VecDuplicate(Xloc, &userO->Yloc); CHKERRQ(ierr);
253   userO->Xceed = ceeddata->Xceed;
254   userO->Yceed = ceeddata->Yceed;
255   userO->op = ceeddata->opApply;
256   userO->ceed = ceed;
257 
258   // Setup solver
259   ierr = KSPCreate(comm, &ksp); CHKERRQ(ierr);
260   {
261     PC pc;
262     ierr = KSPGetPC(ksp, &pc); CHKERRQ(ierr);
263     if (bpChoice == CEED_BP1 || bpChoice == CEED_BP2) {
264       ierr = PCSetType(pc, PCJACOBI); CHKERRQ(ierr);
265       ierr = PCJacobiSetType(pc, PC_JACOBI_ROWSUM); CHKERRQ(ierr);
266     } else {
267       ierr = PCSetType(pc, PCNONE); CHKERRQ(ierr);
268       MatNullSpace nullspace;
269 
270       ierr = MatNullSpaceCreate(PETSC_COMM_WORLD, PETSC_TRUE, 0, 0, &nullspace);
271       CHKERRQ(ierr);
272       ierr = MatSetNullSpace(matO, nullspace); CHKERRQ(ierr);
273       ierr = MatNullSpaceDestroy(&nullspace); CHKERRQ(ierr);
274     }
275     ierr = KSPSetType(ksp, KSPCG); CHKERRQ(ierr);
276     ierr = KSPSetNormType(ksp, KSP_NORM_NATURAL); CHKERRQ(ierr);
277     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT,
278                             PETSC_DEFAULT); CHKERRQ(ierr);
279   }
280   ierr = KSPSetFromOptions(ksp); CHKERRQ(ierr);
281   ierr = KSPSetOperators(ksp, matO, matO); CHKERRQ(ierr);
282 
283   // First run, if benchmarking
284   if (benchmark_mode) {
285     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 1);
286     CHKERRQ(ierr);
287     my_rt_start = MPI_Wtime();
288     ierr = KSPSolve(ksp, rhs, X); CHKERRQ(ierr);
289     my_rt = MPI_Wtime() - my_rt_start;
290     ierr = MPI_Allreduce(MPI_IN_PLACE, &my_rt, 1, MPI_DOUBLE, MPI_MIN, comm);
291     CHKERRQ(ierr);
292     // Set maxits based on first iteration timing
293     if (my_rt > 0.02) {
294       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 5);
295       CHKERRQ(ierr);
296     } else {
297       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 20);
298       CHKERRQ(ierr);
299     }
300   }
301 
302   // Timed solve
303   ierr = VecZeroEntries(X); CHKERRQ(ierr);
304   ierr = PetscBarrier((PetscObject)ksp); CHKERRQ(ierr);
305 
306   // -- Performance logging
307   ierr = PetscLogStageRegister("Solve Stage", &solvestage); CHKERRQ(ierr);
308   ierr = PetscLogStagePush(solvestage); CHKERRQ(ierr);
309 
310   // -- Solve
311   my_rt_start = MPI_Wtime();
312   ierr = KSPSolve(ksp, rhs, X); CHKERRQ(ierr);
313   my_rt = MPI_Wtime() - my_rt_start;
314 
315   // -- Performance logging
316   ierr = PetscLogStagePop();
317 
318   // Output results
319   {
320     KSPType ksptype;
321     KSPConvergedReason reason;
322     PetscReal rnorm;
323     PetscInt its;
324     ierr = KSPGetType(ksp, &ksptype); CHKERRQ(ierr);
325     ierr = KSPGetConvergedReason(ksp, &reason); CHKERRQ(ierr);
326     ierr = KSPGetIterationNumber(ksp, &its); CHKERRQ(ierr);
327     ierr = KSPGetResidualNorm(ksp, &rnorm); CHKERRQ(ierr);
328     if (!test_mode || reason < 0 || rnorm > 1e-8) {
329       ierr = PetscPrintf(comm,
330                          "  KSP:\n"
331                          "    KSP Type                           : %s\n"
332                          "    KSP Convergence                    : %s\n"
333                          "    Total KSP Iterations               : %D\n"
334                          "    Final rnorm                        : %e\n",
335                          ksptype, KSPConvergedReasons[reason], its,
336                          (double)rnorm); CHKERRQ(ierr);
337     }
338     if (!test_mode) {
339       ierr = PetscPrintf(comm,"  Performance:\n"); CHKERRQ(ierr);
340     }
341     {
342       PetscReal maxerror;
343       ierr = ComputeErrorMax(userO, opError, X, target, &maxerror);
344       CHKERRQ(ierr);
345       PetscReal tol = 5e-4;
346       if (!test_mode || maxerror > tol) {
347         ierr = MPI_Allreduce(&my_rt, &rt_min, 1, MPI_DOUBLE, MPI_MIN, comm);
348         CHKERRQ(ierr);
349         ierr = MPI_Allreduce(&my_rt, &rt_max, 1, MPI_DOUBLE, MPI_MAX, comm);
350         CHKERRQ(ierr);
351         ierr = PetscPrintf(comm,
352                            "    Pointwise Error (max)              : %e\n"
353                            "    CG Solve Time                      : %g (%g) sec\n",
354                            (double)maxerror, rt_max, rt_min); CHKERRQ(ierr);
355       }
356     }
357     if (benchmark_mode && (!test_mode)) {
358       ierr = PetscPrintf(comm,
359                          "    DoFs/Sec in CG                     : %g (%g) million\n",
360                          1e-6*gsize*its/rt_max, 1e-6*gsize*its/rt_min); CHKERRQ(ierr);
361     }
362   }
363 
364   // Output solution
365   if (write_solution) {
366     PetscViewer vtkviewersoln;
367 
368     ierr = PetscViewerCreate(comm, &vtkviewersoln); CHKERRQ(ierr);
369     ierr = PetscViewerSetType(vtkviewersoln, PETSCVIEWERVTK); CHKERRQ(ierr);
370     ierr = PetscViewerFileSetName(vtkviewersoln, "solution.vtu"); CHKERRQ(ierr);
371     ierr = VecView(X, vtkviewersoln); CHKERRQ(ierr);
372     ierr = PetscViewerDestroy(&vtkviewersoln); CHKERRQ(ierr);
373   }
374 
375   // Cleanup
376   ierr = VecDestroy(&X); CHKERRQ(ierr);
377   ierr = VecDestroy(&Xloc); CHKERRQ(ierr);
378   ierr = VecDestroy(&userO->Yloc); CHKERRQ(ierr);
379   ierr = MatDestroy(&matO); CHKERRQ(ierr);
380   ierr = PetscFree(userO); CHKERRQ(ierr);
381   ierr = CeedDataDestroy(0, ceeddata); CHKERRQ(ierr);
382   ierr = DMDestroy(&dm); CHKERRQ(ierr);
383 
384   ierr = VecDestroy(&rhs); CHKERRQ(ierr);
385   ierr = VecDestroy(&rhsloc); CHKERRQ(ierr);
386   ierr = KSPDestroy(&ksp); CHKERRQ(ierr);
387   CeedVectorDestroy(&target);
388   CeedQFunctionDestroy(&qfError);
389   CeedOperatorDestroy(&opError);
390   CeedDestroy(&ceed);
391   return PetscFinalize();
392 }
393