xref: /libCEED/examples/petsc/bps.c (revision 82946b17cb1e5ff4e735292ffaa6377862cf1d29)
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 //
22 // The code uses higher level communication protocols in DMPlex.
23 //
24 // Build with:
25 //
26 //     make bps [PETSC_DIR=</path/to/petsc>] [CEED_DIR=</path/to/libceed>]
27 //
28 // Sample runs:
29 //
30 //     ./bps -problem bp1 -degree 3
31 //     ./bps -problem bp2 -ceed /cpu/self -degree 3
32 //     ./bps -problem bp3 -ceed /gpu/occa -degree 3
33 //     ./bps -problem bp4 -ceed /cpu/occa -degree 3
34 //     ./bps -problem bp5 -ceed /omp/occa -degree 3
35 //     ./bps -problem bp6 -ceed /ocl/occa -degree 3
36 //
37 //TESTARGS -ceed {ceed_resource} -test -problem bp5 -degree 3
38 
39 /// @file
40 /// CEED BPs example using PETSc with DMPlex
41 /// See bpsraw.c for a "raw" implementation using a structured grid.
42 const char help[] = "Solve CEED BPs using PETSc with DMPlex\n";
43 
44 #include <stdbool.h>
45 #include <string.h>
46 #include <petscksp.h>
47 #include <petscdmplex.h>
48 #include <ceed.h>
49 #include "setup.h"
50 
51 int main(int argc, char **argv) {
52   PetscInt ierr;
53   MPI_Comm comm;
54   char filename[PETSC_MAX_PATH_LEN],
55        ceedresource[PETSC_MAX_PATH_LEN] = "/cpu/self";
56   double my_rt_start, my_rt, rt_min, rt_max;
57   PetscInt degree = 3, qextra, lsize, gsize, dim = 3, melem[3] = {3, 3, 3},
58            ncompu = 1, xlsize;
59   PetscScalar *r;
60   PetscBool test_mode, benchmark_mode, read_mesh, write_solution;
61   Vec X, Xloc, rhs, rhsloc;
62   Mat matO;
63   KSP ksp;
64   DM  dm;
65   UserO userO;
66   Ceed ceed;
67   CeedData ceeddata;
68   CeedQFunction qf_error;
69   CeedOperator op_error;
70   CeedVector rhsceed, target;
71   bpType bpChoice;
72 
73   ierr = PetscInitialize(&argc, &argv, NULL, help);
74   if (ierr) return ierr;
75   comm = PETSC_COMM_WORLD;
76 
77   // Read command line options
78   ierr = PetscOptionsBegin(comm, NULL, "CEED BPs in PETSc", NULL); CHKERRQ(ierr);
79   bpChoice = CEED_BP1;
80   ierr = PetscOptionsEnum("-problem",
81                           "CEED benchmark problem to solve", NULL,
82                           bpTypes, (PetscEnum)bpChoice, (PetscEnum *)&bpChoice,
83                           NULL); CHKERRQ(ierr);
84   ncompu = bpOptions[bpChoice].ncompu;
85   test_mode = PETSC_FALSE;
86   ierr = PetscOptionsBool("-test",
87                           "Testing mode (do not print unless error is large)",
88                           NULL, test_mode, &test_mode, NULL); CHKERRQ(ierr);
89   benchmark_mode = PETSC_FALSE;
90   ierr = PetscOptionsBool("-benchmark",
91                           "Benchmarking mode (prints benchmark statistics)",
92                           NULL, benchmark_mode, &benchmark_mode, NULL);
93   CHKERRQ(ierr);
94   write_solution = PETSC_FALSE;
95   ierr = PetscOptionsBool("-write_solution",
96                           "Write solution for visualization",
97                           NULL, write_solution, &write_solution, NULL);
98   CHKERRQ(ierr);
99   degree = test_mode ? 3 : 2;
100   ierr = PetscOptionsInt("-degree", "Polynomial degree of tensor product basis",
101                          NULL, degree, &degree, NULL); CHKERRQ(ierr);
102   qextra = bpOptions[bpChoice].qextra;
103   ierr = PetscOptionsInt("-qextra", "Number of extra quadrature points",
104                          NULL, qextra, &qextra, NULL); CHKERRQ(ierr);
105   ierr = PetscOptionsString("-ceed", "CEED resource specifier",
106                             NULL, ceedresource, ceedresource,
107                             sizeof(ceedresource), NULL); CHKERRQ(ierr);
108   read_mesh = PETSC_FALSE;
109   ierr = PetscOptionsString("-mesh", "Read mesh from file", NULL,
110                             filename, filename, sizeof(filename), &read_mesh);
111   CHKERRQ(ierr);
112   if (!read_mesh) {
113     PetscInt tmp = dim;
114     ierr = PetscOptionsIntArray("-cells","Number of cells per dimension", NULL,
115                                 melem, &tmp, NULL); CHKERRQ(ierr);
116   }
117   ierr = PetscOptionsEnd(); CHKERRQ(ierr);
118 
119   // Setup DM
120   if (read_mesh) {
121     ierr = DMPlexCreateFromFile(PETSC_COMM_WORLD, filename, PETSC_TRUE, &dm);
122     CHKERRQ(ierr);
123   } else {
124     ierr = DMPlexCreateBoxMesh(PETSC_COMM_WORLD, dim, PETSC_FALSE, melem, NULL,
125                                NULL, NULL, PETSC_TRUE, &dm); CHKERRQ(ierr);
126   }
127 
128   {
129     DM dmDist = NULL;
130     PetscPartitioner part;
131 
132     ierr = DMPlexGetPartitioner(dm, &part); CHKERRQ(ierr);
133     ierr = PetscPartitionerSetFromOptions(part); CHKERRQ(ierr);
134     ierr = DMPlexDistribute(dm, 0, NULL, &dmDist); CHKERRQ(ierr);
135     if (dmDist) {
136       ierr = DMDestroy(&dm); CHKERRQ(ierr);
137       dm  = dmDist;
138     }
139   }
140 
141   // Create DM
142   ierr = SetupDMByDegree(dm, degree, ncompu, bpChoice);
143   CHKERRQ(ierr);
144 
145   // Create vectors
146   ierr = DMCreateGlobalVector(dm, &X); CHKERRQ(ierr);
147   ierr = VecGetLocalSize(X, &lsize); CHKERRQ(ierr);
148   ierr = VecGetSize(X, &gsize); CHKERRQ(ierr);
149   ierr = DMCreateLocalVector(dm, &Xloc); CHKERRQ(ierr);
150   ierr = VecGetSize(Xloc, &xlsize); CHKERRQ(ierr);
151   ierr = VecDuplicate(X, &rhs); CHKERRQ(ierr);
152 
153   // Operator
154   ierr = PetscMalloc1(1, &userO); CHKERRQ(ierr);
155   ierr = MatCreateShell(comm, lsize, lsize, gsize, gsize,
156                         userO, &matO); CHKERRQ(ierr);
157   ierr = MatShellSetOperation(matO, MATOP_MULT,
158                               (void(*)(void))MatMult_Ceed);
159   CHKERRQ(ierr);
160 
161   // Set up libCEED
162   CeedInit(ceedresource, &ceed);
163 
164   // Print summary
165   if (!test_mode) {
166     PetscInt P = degree + 1, Q = P + qextra;
167     const char *usedresource;
168     CeedGetResource(ceed, &usedresource);
169     ierr = PetscPrintf(comm,
170                        "\n-- CEED Benchmark Problem %d -- libCEED + PETSc --\n"
171                        "  libCEED:\n"
172                        "    libCEED Backend                    : %s\n"
173                        "  Mesh:\n"
174                        "    Number of 1D Basis Nodes (p)       : %d\n"
175                        "    Number of 1D Quadrature Points (q) : %d\n"
176                        "    Global nodes                       : %D\n"
177                        "    Owned nodes                        : %D\n",
178                        bpChoice+1, usedresource, P, Q, gsize/ncompu,
179                        lsize/ncompu); CHKERRQ(ierr);
180   }
181 
182   // Create RHS vector
183   ierr = VecDuplicate(Xloc, &rhsloc); CHKERRQ(ierr);
184   ierr = VecZeroEntries(rhsloc); CHKERRQ(ierr);
185   ierr = VecGetArray(rhsloc, &r); CHKERRQ(ierr);
186   CeedVectorCreate(ceed, xlsize, &rhsceed);
187   CeedVectorSetArray(rhsceed, CEED_MEM_HOST, CEED_USE_POINTER, r);
188 
189   ierr = PetscMalloc1(1, &ceeddata); CHKERRQ(ierr);
190   ierr = SetupLibceedByDegree(dm, ceed, degree, dim, qextra,
191                               ncompu, gsize, xlsize, bpChoice, ceeddata,
192                               true, rhsceed, &target); CHKERRQ(ierr);
193 
194   // Gather RHS
195   ierr = VecRestoreArray(rhsloc, &r); CHKERRQ(ierr);
196   ierr = VecZeroEntries(rhs); CHKERRQ(ierr);
197   ierr = DMLocalToGlobalBegin(dm, rhsloc, ADD_VALUES, rhs); CHKERRQ(ierr);
198   ierr = DMLocalToGlobalEnd(dm, rhsloc, ADD_VALUES, rhs); CHKERRQ(ierr);
199   CeedVectorDestroy(&rhsceed);
200 
201   // Create the error Q-function
202   CeedQFunctionCreateInterior(ceed, 1, bpOptions[bpChoice].error,
203                               bpOptions[bpChoice].errorfname, &qf_error);
204   CeedQFunctionAddInput(qf_error, "u", ncompu, CEED_EVAL_INTERP);
205   CeedQFunctionAddInput(qf_error, "true_soln", ncompu, CEED_EVAL_NONE);
206   CeedQFunctionAddOutput(qf_error, "error", ncompu, CEED_EVAL_NONE);
207 
208   // Create the error operator
209   CeedOperatorCreate(ceed, qf_error, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
210                      &op_error);
211   CeedOperatorSetField(op_error, "u", ceeddata->Erestrictu,
212                        CEED_TRANSPOSE, ceeddata->basisu,
213                        CEED_VECTOR_ACTIVE);
214   CeedOperatorSetField(op_error, "true_soln", ceeddata->Erestrictui,
215                        CEED_NOTRANSPOSE, CEED_BASIS_COLLOCATED, target);
216   CeedOperatorSetField(op_error, "error", ceeddata->Erestrictui,
217                        CEED_NOTRANSPOSE, CEED_BASIS_COLLOCATED,
218                        CEED_VECTOR_ACTIVE);
219 
220   // Set up Mat
221   userO->comm = comm;
222   userO->dm = dm;
223   userO->Xloc = Xloc;
224   ierr = VecDuplicate(Xloc, &userO->Yloc); CHKERRQ(ierr);
225   userO->xceed = ceeddata->xceed;
226   userO->yceed = ceeddata->yceed;
227   userO->op = ceeddata->op_apply;
228   userO->ceed = ceed;
229 
230   ierr = KSPCreate(comm, &ksp); CHKERRQ(ierr);
231   {
232     PC pc;
233     ierr = KSPGetPC(ksp, &pc); CHKERRQ(ierr);
234     if (bpChoice == CEED_BP1 || bpChoice == CEED_BP2) {
235       ierr = PCSetType(pc, PCJACOBI); CHKERRQ(ierr);
236       ierr = PCJacobiSetType(pc, PC_JACOBI_ROWSUM); CHKERRQ(ierr);
237     } else {
238       ierr = PCSetType(pc, PCNONE); CHKERRQ(ierr);
239     }
240     ierr = KSPSetType(ksp, KSPCG); CHKERRQ(ierr);
241     ierr = KSPSetNormType(ksp, KSP_NORM_NATURAL); CHKERRQ(ierr);
242     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT,
243                             PETSC_DEFAULT); CHKERRQ(ierr);
244   }
245   ierr = KSPSetFromOptions(ksp); CHKERRQ(ierr);
246   ierr = KSPSetOperators(ksp, matO, matO); CHKERRQ(ierr);
247 
248   // First run, if benchmarking
249   if (benchmark_mode) {
250     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 1);
251     CHKERRQ(ierr);
252     my_rt_start = MPI_Wtime();
253     ierr = KSPSolve(ksp, rhs, X); CHKERRQ(ierr);
254     my_rt = MPI_Wtime() - my_rt_start;
255     ierr = MPI_Allreduce(MPI_IN_PLACE, &my_rt, 1, MPI_DOUBLE, MPI_MIN, comm);
256     CHKERRQ(ierr);
257     // Set maxits based on first iteration timing
258     if (my_rt > 0.02) {
259       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 5);
260       CHKERRQ(ierr);
261     } else {
262       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 20);
263       CHKERRQ(ierr);
264     }
265   }
266 
267   // Timed solve
268   ierr = VecZeroEntries(X); CHKERRQ(ierr);
269   ierr = PetscBarrier((PetscObject)ksp); CHKERRQ(ierr);
270   my_rt_start = MPI_Wtime();
271   ierr = KSPSolve(ksp, rhs, X); CHKERRQ(ierr);
272   my_rt = MPI_Wtime() - my_rt_start;
273 
274   // Output results
275   {
276     KSPType ksptype;
277     KSPConvergedReason reason;
278     PetscReal rnorm;
279     PetscInt its;
280     ierr = KSPGetType(ksp, &ksptype); CHKERRQ(ierr);
281     ierr = KSPGetConvergedReason(ksp, &reason); CHKERRQ(ierr);
282     ierr = KSPGetIterationNumber(ksp, &its); CHKERRQ(ierr);
283     ierr = KSPGetResidualNorm(ksp, &rnorm); CHKERRQ(ierr);
284     if (!test_mode || reason < 0 || rnorm > 1e-8) {
285       ierr = PetscPrintf(comm,
286                          "  KSP:\n"
287                          "    KSP Type                           : %s\n"
288                          "    KSP Convergence                    : %s\n"
289                          "    Total KSP Iterations               : %D\n"
290                          "    Final rnorm                        : %e\n",
291                          ksptype, KSPConvergedReasons[reason], its,
292                          (double)rnorm); CHKERRQ(ierr);
293     }
294     if (!test_mode) {
295       ierr = PetscPrintf(comm,"  Performance:\n"); CHKERRQ(ierr);
296     }
297     {
298       PetscReal maxerror;
299       ierr = ComputeErrorMax(userO, op_error, X, target, &maxerror);
300       CHKERRQ(ierr);
301       PetscReal tol = 5e-2;
302       if (!test_mode || maxerror > tol) {
303         ierr = MPI_Allreduce(&my_rt, &rt_min, 1, MPI_DOUBLE, MPI_MIN, comm);
304         CHKERRQ(ierr);
305         ierr = MPI_Allreduce(&my_rt, &rt_max, 1, MPI_DOUBLE, MPI_MAX, comm);
306         CHKERRQ(ierr);
307         ierr = PetscPrintf(comm,
308                            "    Pointwise Error (max)              : %e\n"
309                            "    CG Solve Time                      : %g (%g) sec\n",
310                            (double)maxerror, rt_max, rt_min); CHKERRQ(ierr);
311       }
312     }
313     if (benchmark_mode && (!test_mode)) {
314       ierr = PetscPrintf(comm,
315                          "    DoFs/Sec in CG                     : %g (%g) million\n",
316                          1e-6*gsize*its/rt_max,
317                          1e-6*gsize*its/rt_min); CHKERRQ(ierr);
318     }
319   }
320 
321   if (write_solution) {
322     PetscViewer vtkviewersoln;
323 
324     ierr = PetscViewerCreate(comm, &vtkviewersoln); CHKERRQ(ierr);
325     ierr = PetscViewerSetType(vtkviewersoln, PETSCVIEWERVTK); CHKERRQ(ierr);
326     ierr = PetscViewerFileSetName(vtkviewersoln, "solution.vtk"); CHKERRQ(ierr);
327     ierr = VecView(X, vtkviewersoln); CHKERRQ(ierr);
328     ierr = PetscViewerDestroy(&vtkviewersoln); CHKERRQ(ierr);
329   }
330 
331   // Cleanup
332   ierr = VecDestroy(&X); CHKERRQ(ierr);
333   ierr = VecDestroy(&Xloc); CHKERRQ(ierr);
334   ierr = VecDestroy(&userO->Yloc); CHKERRQ(ierr);
335   ierr = MatDestroy(&matO); CHKERRQ(ierr);
336   ierr = PetscFree(userO); CHKERRQ(ierr);
337   ierr = CeedDataDestroy(0, ceeddata); CHKERRQ(ierr);
338   ierr = DMDestroy(&dm); CHKERRQ(ierr);
339 
340   ierr = VecDestroy(&rhs); CHKERRQ(ierr);
341   ierr = VecDestroy(&rhsloc); CHKERRQ(ierr);
342   ierr = KSPDestroy(&ksp); CHKERRQ(ierr);
343   CeedVectorDestroy(&target);
344   CeedQFunctionDestroy(&qf_error);
345   CeedOperatorDestroy(&op_error);
346   CeedDestroy(&ceed);
347   return PetscFinalize();
348 }
349