Actual source code: scotch.c

  1: #include <../src/mat/impls/adj/mpi/mpiadj.h>

  3: EXTERN_C_BEGIN
  4: #include <ptscotch.h>
  5: #if defined(PETSC_HAVE_SCOTCH_PARMETIS_V3_NODEND)
  6: /* we define the prototype instead of include SCOTCH's parmetis.h */
  7: void SCOTCH_ParMETIS_V3_NodeND(const SCOTCH_Num *const, SCOTCH_Num *const, SCOTCH_Num *const, const SCOTCH_Num *const, const SCOTCH_Num *const, SCOTCH_Num *const, SCOTCH_Num *const, MPI_Comm *);
  8: #endif
  9: EXTERN_C_END

 11: typedef struct {
 12:   double     imbalance;
 13:   SCOTCH_Num strategy;
 14: } MatPartitioning_PTScotch;

 16: /*@
 17:   MatPartitioningPTScotchSetImbalance - Sets the value of the load imbalance
 18:   ratio to be used during strategy selection.

 20:   Collective

 22:   Input Parameters:
 23: + part - the partitioning context
 24: - imb  - the load imbalance ratio

 26:   Options Database Key:
 27: . -mat_partitioning_ptscotch_imbalance <imb> - set load imbalance ratio

 29:   Note:
 30:   Must be in the range [0,1]. The default value is 0.01.

 32:   Level: advanced

 34: .seealso: `MATPARTITIONINGSCOTCH`, `MatPartitioningPTScotchSetStrategy()`, `MatPartitioningPTScotchGetImbalance()`
 35: @*/
 36: PetscErrorCode MatPartitioningPTScotchSetImbalance(MatPartitioning part, PetscReal imb)
 37: {
 38:   PetscFunctionBegin;
 41:   PetscTryMethod(part, "MatPartitioningPTScotchSetImbalance_C", (MatPartitioning, PetscReal), (part, imb));
 42:   PetscFunctionReturn(PETSC_SUCCESS);
 43: }

 45: static PetscErrorCode MatPartitioningPTScotchSetImbalance_PTScotch(MatPartitioning part, PetscReal imb)
 46: {
 47:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;

 49:   PetscFunctionBegin;
 50:   if (imb == PETSC_DEFAULT) scotch->imbalance = 0.01;
 51:   else {
 52:     PetscCheck(imb >= 0.0 && imb <= 1.0, PetscObjectComm((PetscObject)part), PETSC_ERR_ARG_OUTOFRANGE, "Illegal value of imb. Must be in range [0,1]");
 53:     scotch->imbalance = (double)imb;
 54:   }
 55:   PetscFunctionReturn(PETSC_SUCCESS);
 56: }

 58: /*@
 59:   MatPartitioningPTScotchGetImbalance - Gets the value of the load imbalance
 60:   ratio used during strategy selection.

 62:   Not Collective

 64:   Input Parameter:
 65: . part - the partitioning context

 67:   Output Parameter:
 68: . imb - the load imbalance ratio

 70:   Level: advanced

 72: .seealso: `MATPARTITIONINGSCOTCH`, `MatPartitioningPTScotchSetImbalance()`
 73: @*/
 74: PetscErrorCode MatPartitioningPTScotchGetImbalance(MatPartitioning part, PetscReal *imb)
 75: {
 76:   PetscFunctionBegin;
 78:   PetscAssertPointer(imb, 2);
 79:   PetscUseMethod(part, "MatPartitioningPTScotchGetImbalance_C", (MatPartitioning, PetscReal *), (part, imb));
 80:   PetscFunctionReturn(PETSC_SUCCESS);
 81: }

 83: static PetscErrorCode MatPartitioningPTScotchGetImbalance_PTScotch(MatPartitioning part, PetscReal *imb)
 84: {
 85:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;

 87:   PetscFunctionBegin;
 88:   *imb = scotch->imbalance;
 89:   PetscFunctionReturn(PETSC_SUCCESS);
 90: }

 92: /*@
 93:   MatPartitioningPTScotchSetStrategy - Sets the strategy to be used in PTScotch.

 95:   Collective

 97:   Input Parameters:
 98: + part     - the partitioning context
 99: - strategy - the strategy, one of
100: .vb
101:      MP_PTSCOTCH_DEFAULT     - Default behavior
102:      MP_PTSCOTCH_QUALITY     - Prioritize quality over speed
103:      MP_PTSCOTCH_SPEED       - Prioritize speed over quality
104:      MP_PTSCOTCH_BALANCE     - Enforce load balance
105:      MP_PTSCOTCH_SAFETY      - Avoid methods that may fail
106:      MP_PTSCOTCH_SCALABILITY - Favor scalability as much as possible
107: .ve

109:   Options Database Key:
110: . -mat_partitioning_ptscotch_strategy [quality,speed,balance,safety,scalability] - strategy

112:   Level: advanced

114:   Note:
115:   The default is `MP_SCOTCH_QUALITY`. See the PTScotch documentation for more information.

117: .seealso: `MATPARTITIONINGSCOTCH`, `MatPartitioningPTScotchSetImbalance()`, `MatPartitioningPTScotchGetStrategy()`
118: @*/
119: PetscErrorCode MatPartitioningPTScotchSetStrategy(MatPartitioning part, MPPTScotchStrategyType strategy)
120: {
121:   PetscFunctionBegin;
124:   PetscTryMethod(part, "MatPartitioningPTScotchSetStrategy_C", (MatPartitioning, MPPTScotchStrategyType), (part, strategy));
125:   PetscFunctionReturn(PETSC_SUCCESS);
126: }

128: static PetscErrorCode MatPartitioningPTScotchSetStrategy_PTScotch(MatPartitioning part, MPPTScotchStrategyType strategy)
129: {
130:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;

132:   PetscFunctionBegin;
133:   switch (strategy) {
134:   case MP_PTSCOTCH_QUALITY:
135:     scotch->strategy = SCOTCH_STRATQUALITY;
136:     break;
137:   case MP_PTSCOTCH_SPEED:
138:     scotch->strategy = SCOTCH_STRATSPEED;
139:     break;
140:   case MP_PTSCOTCH_BALANCE:
141:     scotch->strategy = SCOTCH_STRATBALANCE;
142:     break;
143:   case MP_PTSCOTCH_SAFETY:
144:     scotch->strategy = SCOTCH_STRATSAFETY;
145:     break;
146:   case MP_PTSCOTCH_SCALABILITY:
147:     scotch->strategy = SCOTCH_STRATSCALABILITY;
148:     break;
149:   default:
150:     scotch->strategy = SCOTCH_STRATDEFAULT;
151:     break;
152:   }
153:   PetscFunctionReturn(PETSC_SUCCESS);
154: }

156: /*@
157:   MatPartitioningPTScotchGetStrategy - Gets the strategy used in PTScotch.

159:   Not Collective

161:   Input Parameter:
162: . part - the partitioning context

164:   Output Parameter:
165: . strategy - the strategy

167:   Level: advanced

169: .seealso: `MATPARTITIONINGSCOTCH`, `MatPartitioningPTScotchSetStrategy()`
170: @*/
171: PetscErrorCode MatPartitioningPTScotchGetStrategy(MatPartitioning part, MPPTScotchStrategyType *strategy)
172: {
173:   PetscFunctionBegin;
175:   PetscAssertPointer(strategy, 2);
176:   PetscUseMethod(part, "MatPartitioningPTScotchGetStrategy_C", (MatPartitioning, MPPTScotchStrategyType *), (part, strategy));
177:   PetscFunctionReturn(PETSC_SUCCESS);
178: }

180: static PetscErrorCode MatPartitioningPTScotchGetStrategy_PTScotch(MatPartitioning part, MPPTScotchStrategyType *strategy)
181: {
182:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;

184:   PetscFunctionBegin;
185:   switch (scotch->strategy) {
186:   case SCOTCH_STRATQUALITY:
187:     *strategy = MP_PTSCOTCH_QUALITY;
188:     break;
189:   case SCOTCH_STRATSPEED:
190:     *strategy = MP_PTSCOTCH_SPEED;
191:     break;
192:   case SCOTCH_STRATBALANCE:
193:     *strategy = MP_PTSCOTCH_BALANCE;
194:     break;
195:   case SCOTCH_STRATSAFETY:
196:     *strategy = MP_PTSCOTCH_SAFETY;
197:     break;
198:   case SCOTCH_STRATSCALABILITY:
199:     *strategy = MP_PTSCOTCH_SCALABILITY;
200:     break;
201:   default:
202:     *strategy = MP_PTSCOTCH_DEFAULT;
203:     break;
204:   }
205:   PetscFunctionReturn(PETSC_SUCCESS);
206: }

208: static PetscErrorCode MatPartitioningView_PTScotch(MatPartitioning part, PetscViewer viewer)
209: {
210:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;
211:   PetscBool                 isascii;
212:   const char               *str = NULL;

214:   PetscFunctionBegin;
215:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
216:   if (isascii) {
217:     switch (scotch->strategy) {
218:     case SCOTCH_STRATQUALITY:
219:       str = "Prioritize quality over speed";
220:       break;
221:     case SCOTCH_STRATSPEED:
222:       str = "Prioritize speed over quality";
223:       break;
224:     case SCOTCH_STRATBALANCE:
225:       str = "Enforce load balance";
226:       break;
227:     case SCOTCH_STRATSAFETY:
228:       str = "Avoid methods that may fail";
229:       break;
230:     case SCOTCH_STRATSCALABILITY:
231:       str = "Favor scalability as much as possible";
232:       break;
233:     default:
234:       str = "Default behavior";
235:       break;
236:     }
237:     PetscCall(PetscViewerASCIIPrintf(viewer, "  Strategy=%s\n", str));
238:     PetscCall(PetscViewerASCIIPrintf(viewer, "  Load imbalance ratio=%g\n", scotch->imbalance));
239:   }
240:   PetscFunctionReturn(PETSC_SUCCESS);
241: }

243: static PetscErrorCode MatPartitioningSetFromOptions_PTScotch(MatPartitioning part, PetscOptionItems *PetscOptionsObject)
244: {
245:   PetscBool                 flag;
246:   PetscReal                 r;
247:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;
248:   MPPTScotchStrategyType    strat;

250:   PetscFunctionBegin;
251:   PetscCall(MatPartitioningPTScotchGetStrategy(part, &strat));
252:   PetscOptionsHeadBegin(PetscOptionsObject, "PTScotch partitioning options");
253:   PetscCall(PetscOptionsEnum("-mat_partitioning_ptscotch_strategy", "Strategy", "MatPartitioningPTScotchSetStrategy", MPPTScotchStrategyTypes, (PetscEnum)strat, (PetscEnum *)&strat, &flag));
254:   if (flag) PetscCall(MatPartitioningPTScotchSetStrategy(part, strat));
255:   PetscCall(PetscOptionsReal("-mat_partitioning_ptscotch_imbalance", "Load imbalance ratio", "MatPartitioningPTScotchSetImbalance", scotch->imbalance, &r, &flag));
256:   if (flag) PetscCall(MatPartitioningPTScotchSetImbalance(part, r));
257:   PetscOptionsHeadEnd();
258:   PetscFunctionReturn(PETSC_SUCCESS);
259: }

261: static PetscErrorCode MatPartitioningApply_PTScotch_Private(MatPartitioning part, PetscBool useND, IS *partitioning)
262: {
263:   MPI_Comm                  pcomm, comm;
264:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;
265:   PetscMPIInt               rank;
266:   Mat                       mat = part->adj;
267:   Mat_MPIAdj               *adj = (Mat_MPIAdj *)mat->data;
268:   PetscBool                 flg, distributed;
269:   PetscBool                 proc_weight_flg;
270:   PetscInt                  i, j, p, bs = 1, nold;
271:   PetscInt                 *NDorder = NULL;
272:   PetscReal                *vwgttab, deltval;
273:   SCOTCH_Num               *locals, *velotab, *veloloctab, *edloloctab, vertlocnbr, edgelocnbr, nparts = part->n;

275:   PetscFunctionBegin;
276:   PetscCall(PetscObjectGetComm((PetscObject)part, &pcomm));
277:   /* Duplicate the communicator to be sure that PTSCOTCH attribute caching does not interfere with PETSc. */
278:   PetscCallMPI(MPI_Comm_dup(pcomm, &comm));
279:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
280:   PetscCall(PetscObjectTypeCompare((PetscObject)mat, MATMPIADJ, &flg));
281:   if (!flg) {
282:     /* bs indicates if the converted matrix is "reduced" from the original and hence the
283:        resulting partition results need to be stretched to match the original matrix */
284:     nold = mat->rmap->n;
285:     PetscCall(MatConvert(mat, MATMPIADJ, MAT_INITIAL_MATRIX, &mat));
286:     if (mat->rmap->n > 0) bs = nold / mat->rmap->n;
287:     adj = (Mat_MPIAdj *)mat->data;
288:   }

290:   proc_weight_flg = part->part_weights ? PETSC_TRUE : PETSC_FALSE;
291:   PetscCall(PetscOptionsGetBool(NULL, NULL, "-mat_partitioning_ptscotch_proc_weight", &proc_weight_flg, NULL));

293:   PetscCall(PetscMalloc1(mat->rmap->n + 1, &locals));

295:   if (useND) {
296: #if defined(PETSC_HAVE_SCOTCH_PARMETIS_V3_NODEND)
297:     PetscInt   *sizes, *seps, log2size, subd, *level, base = 0;
298:     PetscMPIInt size;

300:     PetscCallMPI(MPI_Comm_size(comm, &size));
301:     log2size = PetscLog2Real(size);
302:     subd     = PetscPowInt(2, log2size);
303:     PetscCheck(subd == size, comm, PETSC_ERR_SUP, "Only power of 2 communicator sizes");
304:     PetscCall(PetscMalloc1(mat->rmap->n, &NDorder));
305:     PetscCall(PetscMalloc3(2 * size, &sizes, 4 * size, &seps, size, &level));
306:     SCOTCH_ParMETIS_V3_NodeND(mat->rmap->range, adj->i, adj->j, &base, NULL, NDorder, sizes, &comm);
307:     PetscCall(MatPartitioningSizesToSep_Private(subd, sizes, seps, level));
308:     for (i = 0; i < mat->rmap->n; i++) {
309:       PetscInt loc;

311:       PetscCall(PetscFindInt(NDorder[i], 2 * subd, seps, &loc));
312:       if (loc < 0) {
313:         loc = -(loc + 1);
314:         if (loc % 2) { /* part of subdomain */
315:           locals[i] = loc / 2;
316:         } else {
317:           PetscCall(PetscFindInt(NDorder[i], 2 * (subd - 1), seps + 2 * subd, &loc));
318:           loc       = loc < 0 ? -(loc + 1) / 2 : loc / 2;
319:           locals[i] = level[loc];
320:         }
321:       } else locals[i] = loc / 2;
322:     }
323:     PetscCall(PetscFree3(sizes, seps, level));
324: #else
325:     SETERRQ(pcomm, PETSC_ERR_SUP, "Need libptscotchparmetis.a compiled with -DSCOTCH_METIS_PREFIX");
326: #endif
327:   } else {
328:     velotab = NULL;
329:     if (proc_weight_flg) {
330:       PetscCall(PetscMalloc1(nparts, &vwgttab));
331:       PetscCall(PetscMalloc1(nparts, &velotab));
332:       for (j = 0; j < nparts; j++) {
333:         if (part->part_weights) vwgttab[j] = part->part_weights[j] * nparts;
334:         else vwgttab[j] = 1.0;
335:       }
336:       for (i = 0; i < nparts; i++) {
337:         deltval = PetscAbsReal(vwgttab[i] - PetscFloorReal(vwgttab[i] + 0.5));
338:         if (deltval > 0.01) {
339:           for (j = 0; j < nparts; j++) vwgttab[j] /= deltval;
340:         }
341:       }
342:       for (i = 0; i < nparts; i++) velotab[i] = (SCOTCH_Num)(vwgttab[i] + 0.5);
343:       PetscCall(PetscFree(vwgttab));
344:     }

346:     vertlocnbr = mat->rmap->range[rank + 1] - mat->rmap->range[rank];
347:     edgelocnbr = adj->i[vertlocnbr];
348:     veloloctab = part->vertex_weights;
349:     edloloctab = part->use_edge_weights ? adj->values : NULL;

351:     /* detect whether all vertices are located at the same process in original graph */
352:     for (p = 0; !mat->rmap->range[p + 1] && p < nparts; ++p)
353:       ;
354:     distributed = (mat->rmap->range[p + 1] == mat->rmap->N) ? PETSC_FALSE : PETSC_TRUE;
355:     if (distributed) {
356:       SCOTCH_Arch     archdat;
357:       SCOTCH_Dgraph   grafdat;
358:       SCOTCH_Dmapping mappdat;
359:       SCOTCH_Strat    stradat;

361:       PetscCallExternal(SCOTCH_dgraphInit, &grafdat, comm);
362:       PetscCallExternal(SCOTCH_dgraphBuild, &grafdat, 0, vertlocnbr, vertlocnbr, adj->i, adj->i + 1, veloloctab, NULL, edgelocnbr, edgelocnbr, adj->j, NULL, edloloctab);

364:       if (PetscDefined(USE_DEBUG)) PetscCallExternal(SCOTCH_dgraphCheck, &grafdat);

366:       PetscCallExternal(SCOTCH_archInit, &archdat);
367:       PetscCallExternal(SCOTCH_stratInit, &stradat);
368:       PetscCallExternal(SCOTCH_stratDgraphMapBuild, &stradat, scotch->strategy, nparts, nparts, scotch->imbalance);

370:       if (velotab) {
371:         PetscCallExternal(SCOTCH_archCmpltw, &archdat, nparts, velotab);
372:       } else {
373:         PetscCallExternal(SCOTCH_archCmplt, &archdat, nparts);
374:       }
375:       PetscCallExternal(SCOTCH_dgraphMapInit, &grafdat, &mappdat, &archdat, locals);
376:       PetscCallExternal(SCOTCH_dgraphMapCompute, &grafdat, &mappdat, &stradat);

378:       SCOTCH_dgraphMapExit(&grafdat, &mappdat);
379:       SCOTCH_archExit(&archdat);
380:       SCOTCH_stratExit(&stradat);
381:       SCOTCH_dgraphExit(&grafdat);

383:     } else if (rank == p) {
384:       SCOTCH_Graph grafdat;
385:       SCOTCH_Strat stradat;

387:       PetscCallExternal(SCOTCH_graphInit, &grafdat);
388:       PetscCallExternal(SCOTCH_graphBuild, &grafdat, 0, vertlocnbr, adj->i, adj->i + 1, veloloctab, NULL, edgelocnbr, adj->j, edloloctab);
389:       if (PetscDefined(USE_DEBUG)) PetscCallExternal(SCOTCH_graphCheck, &grafdat);
390:       PetscCallExternal(SCOTCH_stratInit, &stradat);
391:       PetscCallExternal(SCOTCH_stratGraphMapBuild, &stradat, scotch->strategy, nparts, scotch->imbalance);
392:       if (velotab) {
393:         SCOTCH_Arch archdat;
394:         PetscCallExternal(SCOTCH_archInit, &archdat);
395:         PetscCallExternal(SCOTCH_archCmpltw, &archdat, nparts, velotab);
396:         PetscCallExternal(SCOTCH_graphMap, &grafdat, &archdat, &stradat, locals);
397:         SCOTCH_archExit(&archdat);
398:       } else {
399:         PetscCallExternal(SCOTCH_graphPart, &grafdat, nparts, &stradat, locals);
400:       }
401:       SCOTCH_stratExit(&stradat);
402:       SCOTCH_graphExit(&grafdat);
403:     }

405:     PetscCall(PetscFree(velotab));
406:   }
407:   PetscCallMPI(MPI_Comm_free(&comm));

409:   if (bs > 1) {
410:     PetscInt *newlocals;
411:     PetscCall(PetscMalloc1(bs * mat->rmap->n, &newlocals));
412:     for (i = 0; i < mat->rmap->n; i++) {
413:       for (j = 0; j < bs; j++) newlocals[bs * i + j] = locals[i];
414:     }
415:     PetscCall(PetscFree(locals));
416:     PetscCall(ISCreateGeneral(pcomm, bs * mat->rmap->n, newlocals, PETSC_OWN_POINTER, partitioning));
417:   } else {
418:     PetscCall(ISCreateGeneral(pcomm, mat->rmap->n, locals, PETSC_OWN_POINTER, partitioning));
419:   }
420:   if (useND) {
421:     IS ndis;

423:     if (bs > 1) {
424:       PetscCall(ISCreateBlock(pcomm, bs, mat->rmap->n, NDorder, PETSC_OWN_POINTER, &ndis));
425:     } else {
426:       PetscCall(ISCreateGeneral(pcomm, mat->rmap->n, NDorder, PETSC_OWN_POINTER, &ndis));
427:     }
428:     PetscCall(ISSetPermutation(ndis));
429:     PetscCall(PetscObjectCompose((PetscObject)(*partitioning), "_petsc_matpartitioning_ndorder", (PetscObject)ndis));
430:     PetscCall(ISDestroy(&ndis));
431:   }

433:   if (!flg) PetscCall(MatDestroy(&mat));
434:   PetscFunctionReturn(PETSC_SUCCESS);
435: }

437: static PetscErrorCode MatPartitioningApply_PTScotch(MatPartitioning part, IS *partitioning)
438: {
439:   PetscFunctionBegin;
440:   PetscCall(MatPartitioningApply_PTScotch_Private(part, PETSC_FALSE, partitioning));
441:   PetscFunctionReturn(PETSC_SUCCESS);
442: }

444: static PetscErrorCode MatPartitioningApplyND_PTScotch(MatPartitioning part, IS *partitioning)
445: {
446:   PetscFunctionBegin;
447:   PetscCall(MatPartitioningApply_PTScotch_Private(part, PETSC_TRUE, partitioning));
448:   PetscFunctionReturn(PETSC_SUCCESS);
449: }

451: static PetscErrorCode MatPartitioningDestroy_PTScotch(MatPartitioning part)
452: {
453:   MatPartitioning_PTScotch *scotch = (MatPartitioning_PTScotch *)part->data;

455:   PetscFunctionBegin;
456:   PetscCall(PetscFree(scotch));
457:   /* clear composed functions */
458:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchSetImbalance_C", NULL));
459:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchGetImbalance_C", NULL));
460:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchSetStrategy_C", NULL));
461:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchGetStrategy_C", NULL));
462:   PetscFunctionReturn(PETSC_SUCCESS);
463: }

465: /*MC
466:    MATPARTITIONINGPTSCOTCH - Creates a partitioning context that uses the external package SCOTCH <http://www.labri.fr/perso/pelegrin/scotch/>.

468:    Level: beginner

470: .seealso: `MatPartitioningSetType()`, `MatPartitioningType`, `MatPartitioningPTScotchSetImbalance()`, `MatPartitioningPTScotchGetImbalance()`,
471:           `MatPartitioningPTScotchSetStrategy()`, `MatPartitioningPTScotchGetStrategy()`, `MatPartitioning`
472: M*/

474: PETSC_EXTERN PetscErrorCode MatPartitioningCreate_PTScotch(MatPartitioning part)
475: {
476:   MatPartitioning_PTScotch *scotch;

478:   PetscFunctionBegin;
479:   PetscCall(PetscNew(&scotch));
480:   part->data = (void *)scotch;

482:   scotch->imbalance = 0.01;
483:   scotch->strategy  = SCOTCH_STRATDEFAULT;

485:   part->ops->apply          = MatPartitioningApply_PTScotch;
486:   part->ops->applynd        = MatPartitioningApplyND_PTScotch;
487:   part->ops->view           = MatPartitioningView_PTScotch;
488:   part->ops->setfromoptions = MatPartitioningSetFromOptions_PTScotch;
489:   part->ops->destroy        = MatPartitioningDestroy_PTScotch;

491:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchSetImbalance_C", MatPartitioningPTScotchSetImbalance_PTScotch));
492:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchGetImbalance_C", MatPartitioningPTScotchGetImbalance_PTScotch));
493:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchSetStrategy_C", MatPartitioningPTScotchSetStrategy_PTScotch));
494:   PetscCall(PetscObjectComposeFunction((PetscObject)part, "MatPartitioningPTScotchGetStrategy_C", MatPartitioningPTScotchGetStrategy_PTScotch));
495:   PetscFunctionReturn(PETSC_SUCCESS);
496: }