xref: /libCEED/examples/petsc/bps.c (revision b3b7035fa845d84f3b306f1f89cf7c89e3d6d1a4)
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 // -----------------------------------------------------------------------------
52 // Utilities
53 // -----------------------------------------------------------------------------
54 
55 // Utility function, compute three factors of an integer
56 static void Split3(PetscInt size, PetscInt m[3], bool reverse) {
57   for (PetscInt d=0,sizeleft=size; d<3; d++) {
58     PetscInt try = (PetscInt)PetscCeilReal(PetscPowReal(sizeleft, 1./(3 - d)));
59     while (try * (sizeleft / try) != sizeleft) try++;
60     m[reverse ? 2-d : d] = try;
61     sizeleft /= try;
62   }
63 }
64 
65 static int Max3(const PetscInt a[3]) {
66   return PetscMax(a[0], PetscMax(a[1], a[2]));
67 }
68 
69 static int Min3(const PetscInt a[3]) {
70   return PetscMin(a[0], PetscMin(a[1], a[2]));
71 }
72 
73 int main(int argc, char **argv) {
74   PetscInt ierr;
75   MPI_Comm comm;
76   char filename[PETSC_MAX_PATH_LEN],
77        ceedresource[PETSC_MAX_PATH_LEN] = "/cpu/self";
78   double my_rt_start, my_rt, rt_min, rt_max;
79   PetscInt degree = 3, qextra, lsize, gsize, dim = 3, melem[3] = {3, 3, 3},
80            ncompu = 1, xlsize, localnodes;
81   PetscScalar *r;
82   PetscBool test_mode, benchmark_mode, read_mesh, write_solution,
83             userlnodes = PETSC_FALSE;
84   PetscLogStage solvestage;
85   Vec X, Xloc, rhs, rhsloc;
86   Mat matO;
87   KSP ksp;
88   DM  dm;
89   UserO userO;
90   Ceed ceed;
91   CeedData ceeddata;
92   CeedQFunction qferror;
93   CeedOperator operror;
94   CeedVector rhsceed, target;
95   CeedMemType memtyperequested;
96   bpType bpchoice;
97 
98   // Check PETSc CUDA support
99   PetscBool petschavecuda, setmemtyperequest = PETSC_FALSE;
100   // *INDENT-OFF*
101   #ifdef PETSC_HAVE_CUDA
102   petschavecuda = PETSC_TRUE;
103   #else
104   petschavecuda = PETSC_FALSE;
105   #endif
106   // *INDENT-ON*
107 
108   ierr = PetscInitialize(&argc, &argv, NULL, help);
109   if (ierr) return ierr;
110   comm = PETSC_COMM_WORLD;
111 
112   // Read command line options
113   ierr = PetscOptionsBegin(comm, NULL, "CEED BPs in PETSc", NULL); CHKERRQ(ierr);
114   bpchoice = CEED_BP1;
115   ierr = PetscOptionsEnum("-problem",
116                           "CEED benchmark problem to solve", NULL,
117                           bpTypes, (PetscEnum)bpchoice, (PetscEnum *)&bpchoice,
118                           NULL); CHKERRQ(ierr);
119   ncompu = bpOptions[bpchoice].ncompu;
120   test_mode = PETSC_FALSE;
121   ierr = PetscOptionsBool("-test",
122                           "Testing mode (do not print unless error is large)",
123                           NULL, test_mode, &test_mode, NULL); CHKERRQ(ierr);
124   benchmark_mode = PETSC_FALSE;
125   ierr = PetscOptionsBool("-benchmark",
126                           "Benchmarking mode (prints benchmark statistics)",
127                           NULL, benchmark_mode, &benchmark_mode, NULL);
128   CHKERRQ(ierr);
129   write_solution = PETSC_FALSE;
130   ierr = PetscOptionsBool("-write_solution",
131                           "Write solution for visualization",
132                           NULL, write_solution, &write_solution, NULL);
133   CHKERRQ(ierr);
134   degree = test_mode ? 3 : 2;
135   ierr = PetscOptionsInt("-degree", "Polynomial degree of tensor product basis",
136                          NULL, degree, &degree, NULL); CHKERRQ(ierr);
137   qextra = bpOptions[bpchoice].qextra;
138   ierr = PetscOptionsInt("-qextra", "Number of extra quadrature points",
139                          NULL, qextra, &qextra, NULL); CHKERRQ(ierr);
140   ierr = PetscOptionsString("-ceed", "CEED resource specifier",
141                             NULL, ceedresource, ceedresource,
142                             sizeof(ceedresource), NULL); CHKERRQ(ierr);
143   read_mesh = PETSC_FALSE;
144   ierr = PetscOptionsString("-mesh", "Read mesh from file", NULL,
145                             filename, filename, sizeof(filename), &read_mesh);
146   CHKERRQ(ierr);
147   if (!read_mesh) {
148     PetscInt tmp = dim;
149     ierr = PetscOptionsIntArray("-cells", "Number of cells per dimension", NULL,
150                                 melem, &tmp, NULL); CHKERRQ(ierr);
151   }
152   memtyperequested = petschavecuda ? CEED_MEM_DEVICE : CEED_MEM_HOST;
153   ierr = PetscOptionsEnum("-memtype",
154                           "CEED MemType requested", NULL,
155                           memTypes, (PetscEnum)memtyperequested,
156                           (PetscEnum *)&memtyperequested, &setmemtyperequest);
157   CHKERRQ(ierr);
158   localnodes = 1000;
159   ierr = PetscOptionsInt("-local_nodes",
160                          "Target number of locally owned nodes per process",
161                          NULL, localnodes, &localnodes, &userlnodes);
162   CHKERRQ(ierr);
163 
164   ierr = PetscOptionsEnd(); CHKERRQ(ierr);
165 
166   // Setup DM
167   if (read_mesh) {
168     ierr = DMPlexCreateFromFile(PETSC_COMM_WORLD, filename, PETSC_TRUE, &dm);
169     CHKERRQ(ierr);
170   } else {
171     if (userlnodes) {
172       // Find a nicely composite number of elements no less than global nodes
173       PetscMPIInt size;
174       ierr = MPI_Comm_size(comm, &size); CHKERRQ(ierr);
175       for (PetscInt gelem = PetscMax(1, size * localnodes / PetscPowInt(degree, dim));
176            ;
177            gelem++) {
178         Split3(gelem, melem, true);
179         if (Max3(melem) / Min3(melem) <= 2) break;
180       }
181     }
182     ierr = DMPlexCreateBoxMesh(PETSC_COMM_WORLD, dim, PETSC_FALSE, melem, NULL,
183                                NULL, NULL, PETSC_TRUE, &dm); CHKERRQ(ierr);
184   }
185 
186   {
187     DM dmDist = NULL;
188     PetscPartitioner part;
189 
190     ierr = DMPlexGetPartitioner(dm, &part); CHKERRQ(ierr);
191     ierr = PetscPartitionerSetFromOptions(part); CHKERRQ(ierr);
192     ierr = DMPlexDistribute(dm, 0, NULL, &dmDist); CHKERRQ(ierr);
193     if (dmDist) {
194       ierr = DMDestroy(&dm); CHKERRQ(ierr);
195       dm  = dmDist;
196     }
197   }
198 
199   // Set up libCEED
200   CeedInit(ceedresource, &ceed);
201   CeedMemType memtypebackend;
202   CeedGetPreferredMemType(ceed, &memtypebackend);
203 
204   // Check memtype compatibility
205   if (!setmemtyperequest)
206     memtyperequested = memtypebackend;
207   else if (!petschavecuda && memtyperequested == CEED_MEM_DEVICE)
208     SETERRQ1(PETSC_COMM_WORLD, PETSC_ERR_SUP_SYS,
209              "PETSc was not built with CUDA. "
210              "Requested MemType CEED_MEM_DEVICE is not supported.", NULL);
211 
212   // Create DM
213   ierr = SetupDMByDegree(dm, degree, ncompu, bpchoice);
214   CHKERRQ(ierr);
215 
216   // Create vectors
217   if (memtyperequested == CEED_MEM_DEVICE) {
218     ierr = DMSetVecType(dm, VECCUDA); CHKERRQ(ierr);
219   }
220   ierr = DMCreateGlobalVector(dm, &X); CHKERRQ(ierr);
221   ierr = VecGetLocalSize(X, &lsize); CHKERRQ(ierr);
222   ierr = VecGetSize(X, &gsize); CHKERRQ(ierr);
223   ierr = DMCreateLocalVector(dm, &Xloc); CHKERRQ(ierr);
224   ierr = VecGetSize(Xloc, &xlsize); CHKERRQ(ierr);
225   ierr = VecDuplicate(X, &rhs); CHKERRQ(ierr);
226 
227   // Operator
228   ierr = PetscMalloc1(1, &userO); CHKERRQ(ierr);
229   ierr = MatCreateShell(comm, lsize, lsize, gsize, gsize,
230                         userO, &matO); CHKERRQ(ierr);
231   ierr = MatShellSetOperation(matO, MATOP_MULT,
232                               (void(*)(void))MatMult_Ceed); CHKERRQ(ierr);
233   ierr = MatShellSetOperation(matO, MATOP_GET_DIAGONAL,
234                               (void(*)(void))MatGetDiag); CHKERRQ(ierr);
235   if (memtyperequested == CEED_MEM_DEVICE) {
236     ierr = MatShellSetVecType(matO, VECCUDA); CHKERRQ(ierr);
237   }
238 
239   // Print summary
240   if (!test_mode) {
241     PetscInt P = degree + 1, Q = P + qextra;
242 
243     const char *usedresource;
244     CeedGetResource(ceed, &usedresource);
245 
246     VecType vectype;
247     ierr = VecGetType(X, &vectype); CHKERRQ(ierr);
248 
249     PetscInt cStart, cEnd;
250     ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd); CHKERRQ(ierr);
251     ierr = PetscPrintf(comm,
252                        "\n-- CEED Benchmark Problem %d -- libCEED + PETSc --\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                        "    libCEED User Requested MemType     : %s\n"
259                        "  Mesh:\n"
260                        "    Number of 1D Basis Nodes (p)       : %d\n"
261                        "    Number of 1D Quadrature Points (q) : %d\n"
262                        "    Global nodes                       : %D\n"
263                        "    Local Elements                     : %D\n"
264                        "    Owned nodes                        : %D\n"
265                        "    DoF per node                       : %D\n",
266                        bpchoice+1, vectype, usedresource,
267                        CeedMemTypes[memtypebackend],
268                        (setmemtyperequest) ?
269                        CeedMemTypes[memtyperequested] : "none",
270                        P, Q, gsize/ncompu, cEnd - cStart, lsize/ncompu,
271                        ncompu);
272     CHKERRQ(ierr);
273   }
274 
275   // Create RHS vector
276   ierr = VecDuplicate(Xloc, &rhsloc); CHKERRQ(ierr);
277   ierr = VecZeroEntries(rhsloc); CHKERRQ(ierr);
278   if (memtyperequested == CEED_MEM_HOST) {
279     ierr = VecGetArray(rhsloc, &r); CHKERRQ(ierr);
280   } else {
281     ierr = VecCUDAGetArray(rhsloc, &r); CHKERRQ(ierr);
282   }
283   CeedVectorCreate(ceed, xlsize, &rhsceed);
284   CeedVectorSetArray(rhsceed, memtyperequested, CEED_USE_POINTER, r);
285 
286   ierr = PetscMalloc1(1, &ceeddata); CHKERRQ(ierr);
287   ierr = SetupLibceedByDegree(dm, ceed, degree, dim, qextra,
288                               ncompu, gsize, xlsize, bpchoice, ceeddata,
289                               true, rhsceed, &target); CHKERRQ(ierr);
290 
291   // Gather RHS
292   CeedVectorSyncArray(rhsceed, memtyperequested);
293   if (memtyperequested == CEED_MEM_HOST) {
294     ierr = VecRestoreArray(rhsloc, &r); CHKERRQ(ierr);
295   } else {
296     ierr = VecCUDARestoreArray(rhsloc, &r); CHKERRQ(ierr);
297   }
298   ierr = VecZeroEntries(rhs); CHKERRQ(ierr);
299   ierr = DMLocalToGlobalBegin(dm, rhsloc, ADD_VALUES, rhs); CHKERRQ(ierr);
300   ierr = DMLocalToGlobalEnd(dm, rhsloc, ADD_VALUES, rhs); CHKERRQ(ierr);
301   CeedVectorDestroy(&rhsceed);
302 
303   // Create the error Q-function
304   CeedQFunctionCreateInterior(ceed, 1, bpOptions[bpchoice].error,
305                               bpOptions[bpchoice].errorfname, &qferror);
306   CeedQFunctionAddInput(qferror, "u", ncompu, CEED_EVAL_INTERP);
307   CeedQFunctionAddInput(qferror, "true_soln", ncompu, CEED_EVAL_NONE);
308   CeedQFunctionAddOutput(qferror, "error", ncompu, CEED_EVAL_NONE);
309 
310   // Create the error operator
311   CeedOperatorCreate(ceed, qferror, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
312                      &operror);
313   CeedOperatorSetField(operror, "u", ceeddata->Erestrictu,
314                        ceeddata->basisu, CEED_VECTOR_ACTIVE);
315   CeedOperatorSetField(operror, "true_soln", ceeddata->Erestrictui,
316                        CEED_BASIS_COLLOCATED, target);
317   CeedOperatorSetField(operror, "error", ceeddata->Erestrictui,
318                        CEED_BASIS_COLLOCATED, CEED_VECTOR_ACTIVE);
319 
320   // Set up Mat
321   userO->comm = comm;
322   userO->dm = dm;
323   userO->Xloc = Xloc;
324   ierr = VecDuplicate(Xloc, &userO->Yloc); CHKERRQ(ierr);
325   userO->xceed = ceeddata->xceed;
326   userO->yceed = ceeddata->yceed;
327   userO->op = ceeddata->opapply;
328   userO->ceed = ceed;
329   userO->memtype = memtyperequested;
330   if (memtyperequested == CEED_MEM_HOST) {
331     userO->VecGetArray = VecGetArray;
332     userO->VecGetArrayRead = VecGetArrayRead;
333     userO->VecRestoreArray = VecRestoreArray;
334     userO->VecRestoreArrayRead = VecRestoreArrayRead;
335   } else {
336     userO->VecGetArray = VecCUDAGetArray;
337     userO->VecGetArrayRead = VecCUDAGetArrayRead;
338     userO->VecRestoreArray = VecCUDARestoreArray;
339     userO->VecRestoreArrayRead = VecCUDARestoreArrayRead;
340   }
341 
342   ierr = KSPCreate(comm, &ksp); CHKERRQ(ierr);
343   {
344     PC pc;
345     ierr = KSPGetPC(ksp, &pc); CHKERRQ(ierr);
346     if (bpchoice == CEED_BP1 || bpchoice == CEED_BP2) {
347       ierr = PCSetType(pc, PCJACOBI); CHKERRQ(ierr);
348       ierr = PCJacobiSetType(pc, PC_JACOBI_ROWSUM); CHKERRQ(ierr);
349     } else {
350       ierr = PCSetType(pc, PCNONE); CHKERRQ(ierr);
351     }
352     ierr = KSPSetType(ksp, KSPCG); CHKERRQ(ierr);
353     ierr = KSPSetNormType(ksp, KSP_NORM_NATURAL); CHKERRQ(ierr);
354     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT,
355                             PETSC_DEFAULT); CHKERRQ(ierr);
356   }
357   ierr = KSPSetOperators(ksp, matO, matO); CHKERRQ(ierr);
358 
359   // First run, if benchmarking
360   if (benchmark_mode) {
361     ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 1);
362     CHKERRQ(ierr);
363     my_rt_start = MPI_Wtime();
364     ierr = KSPSolve(ksp, rhs, X); CHKERRQ(ierr);
365     my_rt = MPI_Wtime() - my_rt_start;
366     ierr = MPI_Allreduce(MPI_IN_PLACE, &my_rt, 1, MPI_DOUBLE, MPI_MIN, comm);
367     CHKERRQ(ierr);
368     // Set maxits based on first iteration timing
369     if (my_rt > 0.02) {
370       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 5);
371       CHKERRQ(ierr);
372     } else {
373       ierr = KSPSetTolerances(ksp, 1e-10, PETSC_DEFAULT, PETSC_DEFAULT, 20);
374       CHKERRQ(ierr);
375     }
376   }
377   ierr = KSPSetFromOptions(ksp); CHKERRQ(ierr);
378 
379   // Timed solve
380   ierr = VecZeroEntries(X); CHKERRQ(ierr);
381   ierr = PetscBarrier((PetscObject)ksp); CHKERRQ(ierr);
382 
383   // -- Performance logging
384   ierr = PetscLogStageRegister("Solve Stage", &solvestage); CHKERRQ(ierr);
385   ierr = PetscLogStagePush(solvestage); CHKERRQ(ierr);
386 
387   // -- Solve
388   my_rt_start = MPI_Wtime();
389   ierr = KSPSolve(ksp, rhs, X); CHKERRQ(ierr);
390   my_rt = MPI_Wtime() - my_rt_start;
391 
392   // -- Performance logging
393   ierr = PetscLogStagePop();
394 
395   // Output results
396   {
397     KSPType ksptype;
398     KSPConvergedReason reason;
399     PetscReal rnorm;
400     PetscInt its;
401     ierr = KSPGetType(ksp, &ksptype); CHKERRQ(ierr);
402     ierr = KSPGetConvergedReason(ksp, &reason); CHKERRQ(ierr);
403     ierr = KSPGetIterationNumber(ksp, &its); CHKERRQ(ierr);
404     ierr = KSPGetResidualNorm(ksp, &rnorm); CHKERRQ(ierr);
405     if (!test_mode || reason < 0 || rnorm > 1e-8) {
406       ierr = PetscPrintf(comm,
407                          "  KSP:\n"
408                          "    KSP Type                           : %s\n"
409                          "    KSP Convergence                    : %s\n"
410                          "    Total KSP Iterations               : %D\n"
411                          "    Final rnorm                        : %e\n",
412                          ksptype, KSPConvergedReasons[reason], its,
413                          (double)rnorm); CHKERRQ(ierr);
414     }
415     if (!test_mode) {
416       ierr = PetscPrintf(comm,"  Performance:\n"); CHKERRQ(ierr);
417     }
418     {
419       PetscReal maxerror;
420       ierr = ComputeErrorMax(userO, operror, X, target, &maxerror);
421       CHKERRQ(ierr);
422       PetscReal tol = 5e-2;
423       if (!test_mode || maxerror > tol) {
424         ierr = MPI_Allreduce(&my_rt, &rt_min, 1, MPI_DOUBLE, MPI_MIN, comm);
425         CHKERRQ(ierr);
426         ierr = MPI_Allreduce(&my_rt, &rt_max, 1, MPI_DOUBLE, MPI_MAX, comm);
427         CHKERRQ(ierr);
428         ierr = PetscPrintf(comm,
429                            "    Pointwise Error (max)              : %e\n"
430                            "    CG Solve Time                      : %g (%g) sec\n",
431                            (double)maxerror, rt_max, rt_min); CHKERRQ(ierr);
432       }
433     }
434     if (benchmark_mode && (!test_mode)) {
435       ierr = PetscPrintf(comm,
436                          "    DoFs/Sec in CG                     : %g (%g) million\n",
437                          1e-6*gsize*its/rt_max,
438                          1e-6*gsize*its/rt_min); CHKERRQ(ierr);
439     }
440   }
441 
442   if (write_solution) {
443     PetscViewer vtkviewersoln;
444 
445     ierr = PetscViewerCreate(comm, &vtkviewersoln); CHKERRQ(ierr);
446     ierr = PetscViewerSetType(vtkviewersoln, PETSCVIEWERVTK); CHKERRQ(ierr);
447     ierr = PetscViewerFileSetName(vtkviewersoln, "solution.vtk"); CHKERRQ(ierr);
448     ierr = VecView(X, vtkviewersoln); CHKERRQ(ierr);
449     ierr = PetscViewerDestroy(&vtkviewersoln); CHKERRQ(ierr);
450   }
451 
452   // Cleanup
453   ierr = VecDestroy(&X); CHKERRQ(ierr);
454   ierr = VecDestroy(&Xloc); CHKERRQ(ierr);
455   ierr = VecDestroy(&userO->Yloc); CHKERRQ(ierr);
456   ierr = MatDestroy(&matO); CHKERRQ(ierr);
457   ierr = PetscFree(userO); CHKERRQ(ierr);
458   ierr = CeedDataDestroy(0, ceeddata); CHKERRQ(ierr);
459   ierr = DMDestroy(&dm); CHKERRQ(ierr);
460 
461   ierr = VecDestroy(&rhs); CHKERRQ(ierr);
462   ierr = VecDestroy(&rhsloc); CHKERRQ(ierr);
463   ierr = KSPDestroy(&ksp); CHKERRQ(ierr);
464   CeedVectorDestroy(&target);
465   CeedQFunctionDestroy(&qferror);
466   CeedOperatorDestroy(&operror);
467   CeedDestroy(&ceed);
468   return PetscFinalize();
469 }
470