xref: /libCEED/examples/petsc/multigrid.c (revision fdf826bb480f6f0c657574035d43bde2679baed8)
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 3-6 with Multigrid
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 multigrid [PETSC_DIR=</path/to/petsc>] [CEED_DIR=</path/to/libceed>]
27 //
28 // Sample runs:
29 //
30 //     multigrid -problem bp3
31 //     multigrid -problem bp4
32 //     multigrid -problem bp5 -ceed /cpu/self
33 //     multigrid -problem bp6 -ceed /gpu/cuda
34 //
35 //TESTARGS -ceed {ceed_resource} -test -problem bp3 -degree 3
36 
37 /// @file
38 /// CEED BPs 1-6 multigrid example using PETSc
39 const char help[] = "Solve CEED BPs using p-multigrid with PETSc and DMPlex\n";
40 
41 #define multigrid
42 #include "setup.h"
43 
44 int main(int argc, char **argv) {
45   PetscInt ierr;
46   MPI_Comm comm;
47   char filename[PETSC_MAX_PATH_LEN],
48        ceedresource[PETSC_MAX_PATH_LEN] = "/cpu/self";
49   double my_rt_start, my_rt, rt_min, rt_max;
50   PetscInt degree = 3, qextra, *lsize, *xlsize, *gsize, dim = 3, fineLevel,
51            melem[3] = {3, 3, 3}, ncompu = 1, numlevels = degree, *leveldegrees;
52   PetscScalar *r;
53   PetscBool test_mode, benchmark_mode, read_mesh, write_solution;
54   PetscLogStage solvestage;
55   DM  *dm, dmorig;
56   SNES snesdummy;
57   KSP ksp;
58   PC pc;
59   Mat *matO, *matPR, matcoarse;
60   Vec *X, *Xloc, *mult, rhs, rhsloc;
61   PetscMemType memtype;
62   UserO *userO;
63   UserProlongRestr *userPR;
64   Ceed ceed;
65   CeedData *ceeddata;
66   CeedVector rhsceed, target;
67   CeedQFunction qferror, qfrestrict, qfprolong;
68   CeedOperator operror;
69   bpType bpchoice;
70   coarsenType coarsen;
71 
72   ierr = PetscInitialize(&argc, &argv, NULL, help);
73   if (ierr) return ierr;
74   comm = PETSC_COMM_WORLD;
75 
76   // Parse command line options
77   ierr = PetscOptionsBegin(comm, NULL, "CEED BPs in PETSc", NULL); CHKERRQ(ierr);
78   bpchoice = CEED_BP3;
79   ierr = PetscOptionsEnum("-problem",
80                           "CEED benchmark problem to solve", NULL,
81                           bpTypes, (PetscEnum)bpchoice, (PetscEnum *)&bpchoice,
82                           NULL); CHKERRQ(ierr);
83   ncompu = bpOptions[bpchoice].ncompu;
84   test_mode = PETSC_FALSE;
85   ierr = PetscOptionsBool("-test",
86                           "Testing mode (do not print unless error is large)",
87                           NULL, test_mode, &test_mode, NULL); CHKERRQ(ierr);
88   benchmark_mode = PETSC_FALSE;
89   ierr = PetscOptionsBool("-benchmark",
90                           "Benchmarking mode (prints benchmark statistics)",
91                           NULL, benchmark_mode, &benchmark_mode, NULL);
92   CHKERRQ(ierr);
93   write_solution = PETSC_FALSE;
94   ierr = PetscOptionsBool("-write_solution",
95                           "Write solution for visualization",
96                           NULL, write_solution, &write_solution, NULL);
97   CHKERRQ(ierr);
98   degree = test_mode ? 3 : 2;
99   ierr = PetscOptionsInt("-degree", "Polynomial degree of tensor product basis",
100                          NULL, degree, &degree, NULL); CHKERRQ(ierr);
101   if (degree < 1) SETERRQ1(PETSC_COMM_WORLD, PETSC_ERR_ARG_OUTOFRANGE,
102                              "-degree %D must be at least 1", degree);
103   qextra = bpOptions[bpchoice].qextra;
104   ierr = PetscOptionsInt("-qextra", "Number of extra quadrature points",
105                          NULL, qextra, &qextra, NULL); CHKERRQ(ierr);
106   ierr = PetscOptionsString("-ceed", "CEED resource specifier",
107                             NULL, ceedresource, ceedresource,
108                             sizeof(ceedresource), NULL); CHKERRQ(ierr);
109   coarsen = COARSEN_UNIFORM;
110   ierr = PetscOptionsEnum("-coarsen",
111                           "Coarsening strategy to use", NULL,
112                           coarsenTypes, (PetscEnum)coarsen,
113                           (PetscEnum *)&coarsen, NULL); CHKERRQ(ierr);
114   read_mesh = PETSC_FALSE;
115   ierr = PetscOptionsString("-mesh", "Read mesh from file", NULL,
116                             filename, filename, sizeof(filename), &read_mesh);
117   CHKERRQ(ierr);
118   if (!read_mesh) {
119     PetscInt tmp = dim;
120     ierr = PetscOptionsIntArray("-cells","Number of cells per dimension", NULL,
121                                 melem, &tmp, NULL); CHKERRQ(ierr);
122   }
123   ierr = PetscOptionsEnd(); CHKERRQ(ierr);
124 
125   // Set up libCEED
126   CeedInit(ceedresource, &ceed);
127   CeedMemType memtypebackend;
128   CeedGetPreferredMemType(ceed, &memtypebackend);
129 
130   // Setup DM
131   if (read_mesh) {
132     ierr = DMPlexCreateFromFile(PETSC_COMM_WORLD, filename, PETSC_TRUE, &dmorig);
133     CHKERRQ(ierr);
134   } else {
135     ierr = DMPlexCreateBoxMesh(PETSC_COMM_WORLD, dim, PETSC_FALSE, melem, NULL,
136                                NULL, NULL, PETSC_TRUE,&dmorig); CHKERRQ(ierr);
137   }
138 
139   {
140     DM dmDist = NULL;
141     PetscPartitioner part;
142 
143     ierr = DMPlexGetPartitioner(dmorig, &part); CHKERRQ(ierr);
144     ierr = PetscPartitionerSetFromOptions(part); CHKERRQ(ierr);
145     ierr = DMPlexDistribute(dmorig, 0, NULL, &dmDist); CHKERRQ(ierr);
146     if (dmDist) {
147       ierr = DMDestroy(&dmorig); CHKERRQ(ierr);
148       dmorig = dmDist;
149     }
150   }
151 
152   VecType vectype;
153   switch (memtypebackend) {
154   case CEED_MEM_HOST: vectype = VECSTANDARD; break;
155   case CEED_MEM_DEVICE: {
156     const char *resolved;
157     CeedGetResource(ceed, &resolved);
158     if (strstr(resolved, "/gpu/cuda")) vectype = VECCUDA;
159     else if (strstr(resolved, "/gpu/hip")) vectype = VECHIP;
160     else vectype = VECSTANDARD;
161   }
162   }
163   ierr = DMSetVecType(dmorig, vectype); CHKERRQ(ierr);
164   ierr = DMSetFromOptions(dmorig); CHKERRQ(ierr);
165 
166   // Allocate arrays for PETSc objects for each level
167   switch (coarsen) {
168   case COARSEN_UNIFORM:
169     numlevels = degree;
170     break;
171   case COARSEN_LOGARITHMIC:
172     numlevels = ceil(log(degree)/log(2)) + 1;
173     break;
174   }
175   ierr = PetscMalloc1(numlevels, &leveldegrees); CHKERRQ(ierr);
176   fineLevel = numlevels - 1;
177 
178   switch (coarsen) {
179   case COARSEN_UNIFORM:
180     for (int i=0; i<numlevels; i++) leveldegrees[i] = i + 1;
181     break;
182   case COARSEN_LOGARITHMIC:
183     for (int i=0; i<numlevels - 1; i++) leveldegrees[i] = pow(2,i);
184     leveldegrees[fineLevel] = degree;
185     break;
186   }
187   ierr = PetscMalloc1(numlevels, &dm); CHKERRQ(ierr);
188   ierr = PetscMalloc1(numlevels, &X); CHKERRQ(ierr);
189   ierr = PetscMalloc1(numlevels, &Xloc); CHKERRQ(ierr);
190   ierr = PetscMalloc1(numlevels, &mult); CHKERRQ(ierr);
191   ierr = PetscMalloc1(numlevels, &userO); CHKERRQ(ierr);
192   ierr = PetscMalloc1(numlevels, &userPR); CHKERRQ(ierr);
193   ierr = PetscMalloc1(numlevels, &matO); CHKERRQ(ierr);
194   ierr = PetscMalloc1(numlevels, &matPR); CHKERRQ(ierr);
195   ierr = PetscMalloc1(numlevels, &lsize); CHKERRQ(ierr);
196   ierr = PetscMalloc1(numlevels, &xlsize); CHKERRQ(ierr);
197   ierr = PetscMalloc1(numlevels, &gsize); CHKERRQ(ierr);
198 
199   // Setup DM and Operator Mat Shells for each level
200   for (CeedInt i=0; i<numlevels; i++) {
201     // Create DM
202     ierr = DMClone(dmorig, &dm[i]); CHKERRQ(ierr);
203     ierr = DMGetVecType(dmorig, &vectype); CHKERRQ(ierr);
204     ierr = DMSetVecType(dm[i], vectype); CHKERRQ(ierr);
205     ierr = SetupDMByDegree(dm[i], leveldegrees[i], ncompu, bpchoice);
206     CHKERRQ(ierr);
207 
208     // Create vectors
209     ierr = DMCreateGlobalVector(dm[i], &X[i]); CHKERRQ(ierr);
210     ierr = VecGetLocalSize(X[i], &lsize[i]); CHKERRQ(ierr);
211     ierr = VecGetSize(X[i], &gsize[i]); CHKERRQ(ierr);
212     ierr = DMCreateLocalVector(dm[i], &Xloc[i]); CHKERRQ(ierr);
213     ierr = VecGetSize(Xloc[i], &xlsize[i]); CHKERRQ(ierr);
214 
215     // Operator
216     ierr = PetscMalloc1(1, &userO[i]); CHKERRQ(ierr);
217     ierr = MatCreateShell(comm, lsize[i], lsize[i], gsize[i], gsize[i],
218                           userO[i], &matO[i]); CHKERRQ(ierr);
219     ierr = MatShellSetOperation(matO[i], MATOP_MULT,
220                                 (void(*)(void))MatMult_Ceed); CHKERRQ(ierr);
221     ierr = MatShellSetOperation(matO[i], MATOP_GET_DIAGONAL,
222                                 (void(*)(void))MatGetDiag); CHKERRQ(ierr);
223     ierr = MatShellSetVecType(matO[i], vectype); CHKERRQ(ierr);
224 
225     // Level transfers
226     if (i > 0) {
227       // Interp
228       ierr = PetscMalloc1(1, &userPR[i]); CHKERRQ(ierr);
229       ierr = MatCreateShell(comm, lsize[i], lsize[i-1], gsize[i], gsize[i-1],
230                             userPR[i], &matPR[i]); CHKERRQ(ierr);
231       ierr = MatShellSetOperation(matPR[i], MATOP_MULT,
232                                   (void(*)(void))MatMult_Prolong);
233       CHKERRQ(ierr);
234       ierr = MatShellSetOperation(matPR[i], MATOP_MULT_TRANSPOSE,
235                                   (void(*)(void))MatMult_Restrict);
236       CHKERRQ(ierr);
237       ierr = MatShellSetVecType(matPR[i], vectype); CHKERRQ(ierr);
238     }
239   }
240   ierr = VecDuplicate(X[fineLevel], &rhs); CHKERRQ(ierr);
241 
242   // Print global grid information
243   if (!test_mode) {
244     PetscInt P = degree + 1, Q = P + qextra;
245 
246     const char *usedresource;
247     CeedGetResource(ceed, &usedresource);
248 
249     ierr = VecGetType(X[0], &vectype); CHKERRQ(ierr);
250 
251     ierr = PetscPrintf(comm,
252                        "\n-- CEED Benchmark Problem %d -- libCEED + PETSc + PCMG --\n"
253                        "  PETSc:\n"
254                        "    PETSc Vec Type                     : %s\n"
255                        "  libCEED:\n"
256                        "    libCEED Backend                    : %s\n"
257                        "    libCEED Backend MemType            : %s\n"
258                        "  Mesh:\n"
259                        "    Number of 1D Basis Nodes (p)       : %d\n"
260                        "    Number of 1D Quadrature Points (q) : %d\n"
261                        "    Global Nodes                       : %D\n"
262                        "    Owned Nodes                        : %D\n"
263                        "    DoF per node                       : %D\n"
264                        "  Multigrid:\n"
265                        "    Number of Levels                   : %d\n",
266                        bpchoice+1, vectype, usedresource,
267                        CeedMemTypes[memtypebackend],
268                        P, Q, gsize[fineLevel]/ncompu, lsize[fineLevel]/ncompu,
269                        ncompu, numlevels); CHKERRQ(ierr);
270   }
271 
272   // Create RHS vector
273   ierr = VecDuplicate(Xloc[fineLevel], &rhsloc); CHKERRQ(ierr);
274   ierr = VecZeroEntries(rhsloc); CHKERRQ(ierr);
275   ierr = VecGetArrayAndMemType(rhsloc, &r, &memtype); CHKERRQ(ierr);
276   CeedVectorCreate(ceed, xlsize[fineLevel], &rhsceed);
277   CeedVectorSetArray(rhsceed, MemTypeP2C(memtype), CEED_USE_POINTER, r);
278 
279   // Set up libCEED operators on each level
280   ierr = PetscMalloc1(numlevels, &ceeddata); CHKERRQ(ierr);
281   for (int i=0; i<numlevels; i++) {
282     // Print level information
283     if (!test_mode && (i == 0 || i == fineLevel)) {
284       ierr = PetscPrintf(comm,"    Level %D (%s):\n"
285                          "      Number of 1D Basis Nodes (p)     : %d\n"
286                          "      Global Nodes                     : %D\n"
287                          "      Owned Nodes                      : %D\n",
288                          i, (i? "fine" : "coarse"), leveldegrees[i] + 1,
289                          gsize[i]/ncompu, lsize[i]/ncompu); CHKERRQ(ierr);
290     }
291     ierr = PetscMalloc1(1, &ceeddata[i]); CHKERRQ(ierr);
292     ierr = SetupLibceedByDegree(dm[i], ceed, leveldegrees[i], dim, qextra,
293                                 ncompu, gsize[i], xlsize[i], bpchoice,
294                                 ceeddata[i], i==(fineLevel), rhsceed, &target);
295     CHKERRQ(ierr);
296   }
297 
298   // Gather RHS
299   CeedVectorTakeArray(rhsceed, MemTypeP2C(memtype), NULL);
300   ierr = VecRestoreArrayAndMemType(rhsloc, &r); CHKERRQ(ierr);
301   ierr = VecZeroEntries(rhs); CHKERRQ(ierr);
302   ierr = DMLocalToGlobal(dm[fineLevel], rhsloc, ADD_VALUES, rhs); CHKERRQ(ierr);
303   CeedVectorDestroy(&rhsceed);
304 
305   // Create the restriction/interpolation QFunction
306   CeedQFunctionCreateIdentity(ceed, ncompu, CEED_EVAL_NONE, CEED_EVAL_INTERP,
307                               &qfrestrict);
308   CeedQFunctionCreateIdentity(ceed, ncompu, CEED_EVAL_INTERP, CEED_EVAL_NONE,
309                               &qfprolong);
310 
311   // Set up libCEED level transfer operators
312   ierr = CeedLevelTransferSetup(ceed, numlevels, ncompu, bpchoice, ceeddata,
313                                 leveldegrees, qfrestrict, qfprolong);
314   CHKERRQ(ierr);
315 
316   // Create the error QFunction
317   CeedQFunctionCreateInterior(ceed, 1, bpOptions[bpchoice].error,
318                               bpOptions[bpchoice].errorfname, &qferror);
319   CeedQFunctionAddInput(qferror, "u", ncompu, CEED_EVAL_INTERP);
320   CeedQFunctionAddInput(qferror, "true_soln", ncompu, CEED_EVAL_NONE);
321   CeedQFunctionAddOutput(qferror, "error", ncompu, CEED_EVAL_NONE);
322 
323   // Create the error operator
324   CeedOperatorCreate(ceed, qferror, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
325                      &operror);
326   CeedOperatorSetField(operror, "u", ceeddata[fineLevel]->Erestrictu,
327                        ceeddata[fineLevel]->basisu, CEED_VECTOR_ACTIVE);
328   CeedOperatorSetField(operror, "true_soln", ceeddata[fineLevel]->Erestrictui,
329                        CEED_BASIS_COLLOCATED, target);
330   CeedOperatorSetField(operror, "error", ceeddata[fineLevel]->Erestrictui,
331                        CEED_BASIS_COLLOCATED, CEED_VECTOR_ACTIVE);
332 
333   // Calculate multiplicity
334   for (int i=0; i<numlevels; i++) {
335     PetscScalar *x;
336 
337     // CEED vector
338     ierr = VecZeroEntries(Xloc[i]); CHKERRQ(ierr);
339     ierr = VecGetArray(Xloc[i], &x); CHKERRQ(ierr);
340     CeedVectorSetArray(ceeddata[i]->xceed, CEED_MEM_HOST, CEED_USE_POINTER, x);
341 
342     // Multiplicity
343     CeedElemRestrictionGetMultiplicity(ceeddata[i]->Erestrictu,
344                                        ceeddata[i]->xceed);
345     CeedVectorSyncArray(ceeddata[i]->xceed, CEED_MEM_HOST);
346 
347     // Restore vector
348     ierr = VecRestoreArray(Xloc[i], &x); CHKERRQ(ierr);
349 
350     // Creat mult vector
351     ierr = VecDuplicate(Xloc[i], &mult[i]); CHKERRQ(ierr);
352 
353     // Local-to-global
354     ierr = VecZeroEntries(X[i]); CHKERRQ(ierr);
355     ierr = DMLocalToGlobal(dm[i], Xloc[i], ADD_VALUES, X[i]);
356     CHKERRQ(ierr);
357     ierr = VecZeroEntries(Xloc[i]); CHKERRQ(ierr);
358 
359     // Global-to-local
360     ierr = DMGlobalToLocal(dm[i], X[i], INSERT_VALUES, mult[i]);
361     CHKERRQ(ierr);
362     ierr = VecZeroEntries(X[i]); CHKERRQ(ierr);
363 
364     // Multiplicity scaling
365     ierr = VecReciprocal(mult[i]);
366   }
367 
368   // Set up Mat
369   for (int i=0; i<numlevels; i++) {
370     // User Operator
371     userO[i]->comm = comm;
372     userO[i]->dm = dm[i];
373     userO[i]->Xloc = Xloc[i];
374     ierr = VecDuplicate(Xloc[i], &userO[i]->Yloc); CHKERRQ(ierr);
375     userO[i]->xceed = ceeddata[i]->xceed;
376     userO[i]->yceed = ceeddata[i]->yceed;
377     userO[i]->op = ceeddata[i]->opapply;
378     userO[i]->ceed = ceed;
379 
380     if (i > 0) {
381       // Prolongation/Restriction Operator
382       userPR[i]->comm = comm;
383       userPR[i]->dmf = dm[i];
384       userPR[i]->dmc = dm[i-1];
385       userPR[i]->locvecc = Xloc[i-1];
386       userPR[i]->locvecf = userO[i]->Yloc;
387       userPR[i]->multvec = mult[i];
388       userPR[i]->ceedvecc = userO[i-1]->xceed;
389       userPR[i]->ceedvecf = userO[i]->yceed;
390       userPR[i]->opprolong = ceeddata[i]->opprolong;
391       userPR[i]->oprestrict = ceeddata[i]->oprestrict;
392       userPR[i]->ceed = ceed;
393     }
394   }
395 
396   // Setup dummy SNES for AMG coarse solve
397   ierr = SNESCreate(comm, &snesdummy); CHKERRQ(ierr);
398   ierr = SNESSetDM(snesdummy, dm[0]); CHKERRQ(ierr);
399   ierr = SNESSetSolution(snesdummy, X[0]); CHKERRQ(ierr);
400 
401   // -- Jacobian matrix
402   ierr = DMSetMatType(dm[0], MATAIJ); CHKERRQ(ierr);
403   ierr = DMCreateMatrix(dm[0], &matcoarse); CHKERRQ(ierr);
404   ierr = SNESSetJacobian(snesdummy, matcoarse, matcoarse, NULL,
405                          NULL); CHKERRQ(ierr);
406 
407   // -- Residual evaluation function
408   ierr = SNESSetFunction(snesdummy, X[0], FormResidual_Ceed,
409                          userO[0]); CHKERRQ(ierr);
410 
411   // -- Form Jacobian
412   ierr = SNESComputeJacobianDefaultColor(snesdummy, X[0], matO[0],
413                                          matcoarse, NULL); CHKERRQ(ierr);
414 
415   // Set up KSP
416   ierr = KSPCreate(comm, &ksp); CHKERRQ(ierr);
417   {
418     ierr = KSPSetType(ksp, KSPCG); CHKERRQ(ierr);
419     ierr = KSPSetNormType(ksp, KSP_NORM_NATURAL); CHKERRQ(ierr);
420     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT,
421                             PETSC_DEFAULT); CHKERRQ(ierr);
422   }
423   ierr = KSPSetFromOptions(ksp); CHKERRQ(ierr);
424   ierr = KSPSetOperators(ksp, matO[fineLevel], matO[fineLevel]);
425   CHKERRQ(ierr);
426 
427   // Set up PCMG
428   ierr = KSPGetPC(ksp, &pc); CHKERRQ(ierr);
429   PCMGCycleType pcgmcycletype = PC_MG_CYCLE_V;
430   {
431     ierr = PCSetType(pc, PCMG); CHKERRQ(ierr);
432 
433     // PCMG levels
434     ierr = PCMGSetLevels(pc, numlevels, NULL); CHKERRQ(ierr);
435     for (int i=0; i<numlevels; i++) {
436       // Smoother
437       KSP smoother;
438       PC smoother_pc;
439       ierr = PCMGGetSmoother(pc, i, &smoother); CHKERRQ(ierr);
440       ierr = KSPSetType(smoother, KSPCHEBYSHEV); CHKERRQ(ierr);
441       ierr = KSPChebyshevEstEigSet(smoother, 0, 0.1, 0, 1.1); CHKERRQ(ierr);
442       ierr = KSPChebyshevEstEigSetUseNoisy(smoother, PETSC_TRUE); CHKERRQ(ierr);
443       ierr = KSPSetOperators(smoother, matO[i], matO[i]); CHKERRQ(ierr);
444       ierr = KSPGetPC(smoother, &smoother_pc); CHKERRQ(ierr);
445       ierr = PCSetType(smoother_pc, PCJACOBI); CHKERRQ(ierr);
446       ierr = PCJacobiSetType(smoother_pc, PC_JACOBI_DIAGONAL); CHKERRQ(ierr);
447 
448       // Work vector
449       if (i < numlevels - 1) {
450         ierr = PCMGSetX(pc, i, X[i]); CHKERRQ(ierr);
451       }
452 
453       // Level transfers
454       if (i > 0) {
455         // Interpolation
456         ierr = PCMGSetInterpolation(pc, i, matPR[i]); CHKERRQ(ierr);
457       }
458 
459       // Coarse solve
460       KSP coarse;
461       PC coarse_pc;
462       ierr = PCMGGetCoarseSolve(pc, &coarse); CHKERRQ(ierr);
463       ierr = KSPSetType(coarse, KSPPREONLY); CHKERRQ(ierr);
464       ierr = KSPSetOperators(coarse, matcoarse, matcoarse); CHKERRQ(ierr);
465 
466       ierr = KSPGetPC(coarse, &coarse_pc); CHKERRQ(ierr);
467       ierr = PCSetType(coarse_pc, PCGAMG); CHKERRQ(ierr);
468 
469       ierr = KSPSetOptionsPrefix(coarse, "coarse_"); CHKERRQ(ierr);
470       ierr = PCSetOptionsPrefix(coarse_pc, "coarse_"); CHKERRQ(ierr);
471       ierr = KSPSetFromOptions(coarse); CHKERRQ(ierr);
472       ierr = PCSetFromOptions(coarse_pc); CHKERRQ(ierr);
473     }
474 
475     // PCMG options
476     ierr = PCMGSetType(pc, PC_MG_MULTIPLICATIVE); CHKERRQ(ierr);
477     ierr = PCMGSetNumberSmooth(pc, 3); CHKERRQ(ierr);
478     ierr = PCMGSetCycleType(pc, pcgmcycletype); CHKERRQ(ierr);
479   }
480 
481   // First run, if benchmarking
482   if (benchmark_mode) {
483     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 1);
484     CHKERRQ(ierr);
485     ierr = VecZeroEntries(X[fineLevel]); CHKERRQ(ierr);
486     my_rt_start = MPI_Wtime();
487     ierr = KSPSolve(ksp, rhs, X[fineLevel]); CHKERRQ(ierr);
488     my_rt = MPI_Wtime() - my_rt_start;
489     ierr = MPI_Allreduce(MPI_IN_PLACE, &my_rt, 1, MPI_DOUBLE, MPI_MIN, comm);
490     CHKERRQ(ierr);
491     // Set maxits based on first iteration timing
492     if (my_rt > 0.02) {
493       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 5);
494       CHKERRQ(ierr);
495     } else {
496       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 20);
497       CHKERRQ(ierr);
498     }
499   }
500 
501   // Timed solve
502   ierr = VecZeroEntries(X[fineLevel]); CHKERRQ(ierr);
503   ierr = PetscBarrier((PetscObject)ksp); CHKERRQ(ierr);
504 
505   // -- Performance logging
506   ierr = PetscLogStageRegister("Solve Stage", &solvestage); CHKERRQ(ierr);
507   ierr = PetscLogStagePush(solvestage); CHKERRQ(ierr);
508 
509   // -- Solve
510   my_rt_start = MPI_Wtime();
511   ierr = KSPSolve(ksp, rhs, X[fineLevel]); CHKERRQ(ierr);
512   my_rt = MPI_Wtime() - my_rt_start;
513 
514 
515   // -- Performance logging
516   ierr = PetscLogStagePop();
517 
518   // Output results
519   {
520     KSPType ksptype;
521     PCMGType pcmgtype;
522     KSPConvergedReason reason;
523     PetscReal rnorm;
524     PetscInt its;
525     ierr = KSPGetType(ksp, &ksptype); CHKERRQ(ierr);
526     ierr = KSPGetConvergedReason(ksp, &reason); CHKERRQ(ierr);
527     ierr = KSPGetIterationNumber(ksp, &its); CHKERRQ(ierr);
528     ierr = KSPGetResidualNorm(ksp, &rnorm); CHKERRQ(ierr);
529     ierr = PCMGGetType(pc, &pcmgtype); CHKERRQ(ierr);
530     if (!test_mode || reason < 0 || rnorm > 1e-8) {
531       ierr = PetscPrintf(comm,
532                          "  KSP:\n"
533                          "    KSP Type                           : %s\n"
534                          "    KSP Convergence                    : %s\n"
535                          "    Total KSP Iterations               : %D\n"
536                          "    Final rnorm                        : %e\n",
537                          ksptype, KSPConvergedReasons[reason], its,
538                          (double)rnorm); CHKERRQ(ierr);
539       ierr = PetscPrintf(comm,
540                          "  PCMG:\n"
541                          "    PCMG Type                          : %s\n"
542                          "    PCMG Cycle Type                    : %s\n",
543                          PCMGTypes[pcmgtype],
544                          PCMGCycleTypes[pcgmcycletype]); CHKERRQ(ierr);
545     }
546     if (!test_mode) {
547       ierr = PetscPrintf(comm,"  Performance:\n"); CHKERRQ(ierr);
548     }
549     {
550       PetscReal maxerror;
551       ierr = ComputeErrorMax(userO[fineLevel], operror, X[fineLevel], target,
552                              &maxerror); CHKERRQ(ierr);
553       PetscReal tol = 5e-2;
554       if (!test_mode || maxerror > tol) {
555         ierr = MPI_Allreduce(&my_rt, &rt_min, 1, MPI_DOUBLE, MPI_MIN, comm);
556         CHKERRQ(ierr);
557         ierr = MPI_Allreduce(&my_rt, &rt_max, 1, MPI_DOUBLE, MPI_MAX, comm);
558         CHKERRQ(ierr);
559         ierr = PetscPrintf(comm,
560                            "    Pointwise Error (max)              : %e\n"
561                            "    CG Solve Time                      : %g (%g) sec\n",
562                            (double)maxerror, rt_max, rt_min); CHKERRQ(ierr);
563       }
564     }
565     if (benchmark_mode && (!test_mode)) {
566       ierr = PetscPrintf(comm,
567                          "    DoFs/Sec in CG                     : %g (%g) million\n",
568                          1e-6*gsize[fineLevel]*its/rt_max,
569                          1e-6*gsize[fineLevel]*its/rt_min);
570       CHKERRQ(ierr);
571     }
572   }
573 
574   if (write_solution) {
575     PetscViewer vtkviewersoln;
576 
577     ierr = PetscViewerCreate(comm, &vtkviewersoln); CHKERRQ(ierr);
578     ierr = PetscViewerSetType(vtkviewersoln, PETSCVIEWERVTK); CHKERRQ(ierr);
579     ierr = PetscViewerFileSetName(vtkviewersoln, "solution.vtk"); CHKERRQ(ierr);
580     ierr = VecView(X[fineLevel], vtkviewersoln); CHKERRQ(ierr);
581     ierr = PetscViewerDestroy(&vtkviewersoln); CHKERRQ(ierr);
582   }
583 
584   // Cleanup
585   for (int i=0; i<numlevels; i++) {
586     ierr = VecDestroy(&X[i]); CHKERRQ(ierr);
587     ierr = VecDestroy(&Xloc[i]); CHKERRQ(ierr);
588     ierr = VecDestroy(&mult[i]); CHKERRQ(ierr);
589     ierr = VecDestroy(&userO[i]->Yloc); CHKERRQ(ierr);
590     ierr = MatDestroy(&matO[i]); CHKERRQ(ierr);
591     ierr = PetscFree(userO[i]); CHKERRQ(ierr);
592     if (i > 0) {
593       ierr = MatDestroy(&matPR[i]); CHKERRQ(ierr);
594       ierr = PetscFree(userPR[i]); CHKERRQ(ierr);
595     }
596     ierr = CeedDataDestroy(i, ceeddata[i]); CHKERRQ(ierr);
597     ierr = DMDestroy(&dm[i]); CHKERRQ(ierr);
598   }
599   ierr = PetscFree(leveldegrees); CHKERRQ(ierr);
600   ierr = PetscFree(dm); CHKERRQ(ierr);
601   ierr = PetscFree(X); CHKERRQ(ierr);
602   ierr = PetscFree(Xloc); CHKERRQ(ierr);
603   ierr = PetscFree(mult); CHKERRQ(ierr);
604   ierr = PetscFree(matO); CHKERRQ(ierr);
605   ierr = PetscFree(matPR); CHKERRQ(ierr);
606   ierr = PetscFree(ceeddata); CHKERRQ(ierr);
607   ierr = PetscFree(userO); CHKERRQ(ierr);
608   ierr = PetscFree(userPR); CHKERRQ(ierr);
609   ierr = PetscFree(lsize); CHKERRQ(ierr);
610   ierr = PetscFree(xlsize); CHKERRQ(ierr);
611   ierr = PetscFree(gsize); CHKERRQ(ierr);
612   ierr = VecDestroy(&rhs); CHKERRQ(ierr);
613   ierr = VecDestroy(&rhsloc); CHKERRQ(ierr);
614   ierr = MatDestroy(&matcoarse); CHKERRQ(ierr);
615   ierr = KSPDestroy(&ksp); CHKERRQ(ierr);
616   ierr = SNESDestroy(&snesdummy); CHKERRQ(ierr);
617   ierr = DMDestroy(&dmorig); CHKERRQ(ierr);
618   CeedVectorDestroy(&target);
619   CeedQFunctionDestroy(&qferror);
620   CeedQFunctionDestroy(&qfrestrict);
621   CeedQFunctionDestroy(&qfprolong);
622   CeedOperatorDestroy(&operror);
623   CeedDestroy(&ceed);
624   return PetscFinalize();
625 }
626