Actual source code: asm.c
1: /*
2: This file defines an additive Schwarz preconditioner for any Mat implementation.
4: Note that each processor may have any number of subdomains. But in order to
5: deal easily with the VecScatter(), we treat each processor as if it has the
6: same number of subdomains.
8: n - total number of true subdomains on all processors
9: n_local_true - actual number of subdomains on this processor
10: n_local = maximum over all processors of n_local_true
11: */
13: #include <petsc/private/pcasmimpl.h>
14: #include <petsc/private/matimpl.h>
16: static PetscErrorCode PCView_ASM(PC pc, PetscViewer viewer)
17: {
18: PC_ASM *osm = (PC_ASM *)pc->data;
19: PetscMPIInt rank;
20: PetscInt i, bsz;
21: PetscBool iascii, isstring;
22: PetscViewer sviewer;
23: PetscViewerFormat format;
24: const char *prefix;
26: PetscFunctionBegin;
27: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
28: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
29: if (iascii) {
30: char overlaps[256] = "user-defined overlap", blocks[256] = "total subdomain blocks not yet set";
31: if (osm->overlap >= 0) PetscCall(PetscSNPrintf(overlaps, sizeof(overlaps), "amount of overlap = %" PetscInt_FMT, osm->overlap));
32: if (osm->n > 0) PetscCall(PetscSNPrintf(blocks, sizeof(blocks), "total subdomain blocks = %" PetscInt_FMT, osm->n));
33: PetscCall(PetscViewerASCIIPrintf(viewer, " %s, %s\n", blocks, overlaps));
34: PetscCall(PetscViewerASCIIPrintf(viewer, " restriction/interpolation type - %s\n", PCASMTypes[osm->type]));
35: if (osm->dm_subdomains) PetscCall(PetscViewerASCIIPrintf(viewer, " Additive Schwarz: using DM to define subdomains\n"));
36: if (osm->loctype != PC_COMPOSITE_ADDITIVE) PetscCall(PetscViewerASCIIPrintf(viewer, " Additive Schwarz: local solve composition type - %s\n", PCCompositeTypes[osm->loctype]));
37: PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank));
38: PetscCall(PetscViewerGetFormat(viewer, &format));
39: if (format != PETSC_VIEWER_ASCII_INFO_DETAIL) {
40: if (osm->ksp) {
41: PetscCall(PetscViewerASCIIPrintf(viewer, " Local solver information for first block is in the following KSP and PC objects on rank 0:\n"));
42: PetscCall(PCGetOptionsPrefix(pc, &prefix));
43: PetscCall(PetscViewerASCIIPrintf(viewer, " Use -%sksp_view ::ascii_info_detail to display information for all blocks\n", prefix ? prefix : ""));
44: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
45: if (rank == 0) {
46: PetscCall(PetscViewerASCIIPushTab(sviewer));
47: PetscCall(KSPView(osm->ksp[0], sviewer));
48: PetscCall(PetscViewerASCIIPopTab(sviewer));
49: }
50: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
51: }
52: } else {
53: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
54: PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " [%d] number of local blocks = %" PetscInt_FMT "\n", rank, osm->n_local_true));
55: PetscCall(PetscViewerFlush(viewer));
56: PetscCall(PetscViewerASCIIPrintf(viewer, " Local solver information for each block is in the following KSP and PC objects:\n"));
57: PetscCall(PetscViewerASCIIPushTab(viewer));
58: PetscCall(PetscViewerASCIIPrintf(viewer, "- - - - - - - - - - - - - - - - - -\n"));
59: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
60: for (i = 0; i < osm->n_local_true; i++) {
61: PetscCall(ISGetLocalSize(osm->is[i], &bsz));
62: PetscCall(PetscViewerASCIIPrintf(sviewer, "[%d] local block number %" PetscInt_FMT ", size = %" PetscInt_FMT "\n", rank, i, bsz));
63: PetscCall(KSPView(osm->ksp[i], sviewer));
64: PetscCall(PetscViewerASCIIPrintf(sviewer, "- - - - - - - - - - - - - - - - - -\n"));
65: }
66: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
67: PetscCall(PetscViewerASCIIPopTab(viewer));
68: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
69: }
70: } else if (isstring) {
71: PetscCall(PetscViewerStringSPrintf(viewer, " blocks=%" PetscInt_FMT ", overlap=%" PetscInt_FMT ", type=%s", osm->n, osm->overlap, PCASMTypes[osm->type]));
72: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
73: if (osm->ksp) PetscCall(KSPView(osm->ksp[0], sviewer));
74: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
75: }
76: PetscFunctionReturn(PETSC_SUCCESS);
77: }
79: static PetscErrorCode PCASMPrintSubdomains(PC pc)
80: {
81: PC_ASM *osm = (PC_ASM *)pc->data;
82: const char *prefix;
83: char fname[PETSC_MAX_PATH_LEN + 1];
84: PetscViewer viewer, sviewer;
85: char *s;
86: PetscInt i, j, nidx;
87: const PetscInt *idx;
88: PetscMPIInt rank, size;
90: PetscFunctionBegin;
91: PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size));
92: PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank));
93: PetscCall(PCGetOptionsPrefix(pc, &prefix));
94: PetscCall(PetscOptionsGetString(NULL, prefix, "-pc_asm_print_subdomains", fname, sizeof(fname), NULL));
95: if (fname[0] == 0) PetscCall(PetscStrncpy(fname, "stdout", sizeof(fname)));
96: PetscCall(PetscViewerASCIIOpen(PetscObjectComm((PetscObject)pc), fname, &viewer));
97: for (i = 0; i < osm->n_local; i++) {
98: if (i < osm->n_local_true) {
99: PetscCall(ISGetLocalSize(osm->is[i], &nidx));
100: PetscCall(ISGetIndices(osm->is[i], &idx));
101: /* Print to a string viewer; no more than 15 characters per index plus 512 char for the header.*/
102: #define len 16 * (nidx + 1) + 512
103: PetscCall(PetscMalloc1(len, &s));
104: PetscCall(PetscViewerStringOpen(PETSC_COMM_SELF, s, len, &sviewer));
105: #undef len
106: PetscCall(PetscViewerStringSPrintf(sviewer, "[%d:%d] Subdomain %" PetscInt_FMT " with overlap:\n", rank, size, i));
107: for (j = 0; j < nidx; j++) PetscCall(PetscViewerStringSPrintf(sviewer, "%" PetscInt_FMT " ", idx[j]));
108: PetscCall(ISRestoreIndices(osm->is[i], &idx));
109: PetscCall(PetscViewerStringSPrintf(sviewer, "\n"));
110: PetscCall(PetscViewerDestroy(&sviewer));
111: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
112: PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%s", s));
113: PetscCall(PetscViewerFlush(viewer));
114: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
115: PetscCall(PetscFree(s));
116: if (osm->is_local) {
117: /* Print to a string viewer; no more than 15 characters per index plus 512 char for the header.*/
118: #define len 16 * (nidx + 1) + 512
119: PetscCall(PetscMalloc1(len, &s));
120: PetscCall(PetscViewerStringOpen(PETSC_COMM_SELF, s, len, &sviewer));
121: #undef len
122: PetscCall(PetscViewerStringSPrintf(sviewer, "[%d:%d] Subdomain %" PetscInt_FMT " without overlap:\n", rank, size, i));
123: PetscCall(ISGetLocalSize(osm->is_local[i], &nidx));
124: PetscCall(ISGetIndices(osm->is_local[i], &idx));
125: for (j = 0; j < nidx; j++) PetscCall(PetscViewerStringSPrintf(sviewer, "%" PetscInt_FMT " ", idx[j]));
126: PetscCall(ISRestoreIndices(osm->is_local[i], &idx));
127: PetscCall(PetscViewerStringSPrintf(sviewer, "\n"));
128: PetscCall(PetscViewerDestroy(&sviewer));
129: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
130: PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%s", s));
131: PetscCall(PetscViewerFlush(viewer));
132: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
133: PetscCall(PetscFree(s));
134: }
135: } else {
136: /* Participate in collective viewer calls. */
137: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
138: PetscCall(PetscViewerFlush(viewer));
139: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
140: /* Assume either all ranks have is_local or none do. */
141: if (osm->is_local) {
142: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
143: PetscCall(PetscViewerFlush(viewer));
144: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
145: }
146: }
147: }
148: PetscCall(PetscViewerFlush(viewer));
149: PetscCall(PetscViewerDestroy(&viewer));
150: PetscFunctionReturn(PETSC_SUCCESS);
151: }
153: static PetscErrorCode PCSetUp_ASM(PC pc)
154: {
155: PC_ASM *osm = (PC_ASM *)pc->data;
156: PetscBool flg;
157: PetscInt i, m, m_local;
158: MatReuse scall = MAT_REUSE_MATRIX;
159: IS isl;
160: KSP ksp;
161: PC subpc;
162: const char *prefix, *pprefix;
163: Vec vec;
164: DM *domain_dm = NULL;
165: MatNullSpace *nullsp = NULL;
167: PetscFunctionBegin;
168: if (!pc->setupcalled) {
169: PetscInt m;
171: /* Note: if subdomains have been set either via PCASMSetTotalSubdomains() or via PCASMSetLocalSubdomains(), osm->n_local_true will not be PETSC_DECIDE */
172: if (osm->n_local_true == PETSC_DECIDE) {
173: /* no subdomains given */
174: /* try pc->dm first, if allowed */
175: if (osm->dm_subdomains && pc->dm) {
176: PetscInt num_domains, d;
177: char **domain_names;
178: IS *inner_domain_is, *outer_domain_is;
179: PetscCall(DMCreateDomainDecomposition(pc->dm, &num_domains, &domain_names, &inner_domain_is, &outer_domain_is, &domain_dm));
180: osm->overlap = -1; /* We do not want to increase the overlap of the IS.
181: A future improvement of this code might allow one to use
182: DM-defined subdomains and also increase the overlap,
183: but that is not currently supported */
184: if (num_domains) PetscCall(PCASMSetLocalSubdomains(pc, num_domains, outer_domain_is, inner_domain_is));
185: for (d = 0; d < num_domains; ++d) {
186: if (domain_names) PetscCall(PetscFree(domain_names[d]));
187: if (inner_domain_is) PetscCall(ISDestroy(&inner_domain_is[d]));
188: if (outer_domain_is) PetscCall(ISDestroy(&outer_domain_is[d]));
189: }
190: PetscCall(PetscFree(domain_names));
191: PetscCall(PetscFree(inner_domain_is));
192: PetscCall(PetscFree(outer_domain_is));
193: }
194: if (osm->n_local_true == PETSC_DECIDE) {
195: /* still no subdomains; use one subdomain per processor */
196: osm->n_local_true = 1;
197: }
198: }
199: { /* determine the global and max number of subdomains */
200: struct {
201: PetscInt max, sum;
202: } inwork, outwork;
203: PetscMPIInt size;
205: inwork.max = osm->n_local_true;
206: inwork.sum = osm->n_local_true;
207: PetscCallMPI(MPIU_Allreduce(&inwork, &outwork, 1, MPIU_2INT, MPIU_MAXSUM_OP, PetscObjectComm((PetscObject)pc)));
208: osm->n_local = outwork.max;
209: osm->n = outwork.sum;
211: PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size));
212: if (outwork.max == 1 && outwork.sum == size) {
213: /* osm->n_local_true = 1 on all processes, set this option may enable use of optimized MatCreateSubMatrices() implementation */
214: PetscCall(MatSetOption(pc->pmat, MAT_SUBMAT_SINGLEIS, PETSC_TRUE));
215: }
216: }
217: if (!osm->is) { /* create the index sets */
218: PetscCall(PCASMCreateSubdomains(pc->pmat, osm->n_local_true, &osm->is));
219: }
220: if (osm->n_local_true > 1 && !osm->is_local) {
221: PetscCall(PetscMalloc1(osm->n_local_true, &osm->is_local));
222: for (i = 0; i < osm->n_local_true; i++) {
223: if (osm->overlap > 0) { /* With positive overlap, osm->is[i] will be modified */
224: PetscCall(ISDuplicate(osm->is[i], &osm->is_local[i]));
225: PetscCall(ISCopy(osm->is[i], osm->is_local[i]));
226: } else {
227: PetscCall(PetscObjectReference((PetscObject)osm->is[i]));
228: osm->is_local[i] = osm->is[i];
229: }
230: }
231: }
232: PetscCall(PCGetOptionsPrefix(pc, &prefix));
233: if (osm->overlap > 0) {
234: /* Extend the "overlapping" regions by a number of steps */
235: PetscCall(MatIncreaseOverlap(pc->pmat, osm->n_local_true, osm->is, osm->overlap));
236: }
237: if (osm->sort_indices) {
238: for (i = 0; i < osm->n_local_true; i++) {
239: PetscCall(ISSort(osm->is[i]));
240: if (osm->is_local) PetscCall(ISSort(osm->is_local[i]));
241: }
242: }
243: flg = PETSC_FALSE;
244: PetscCall(PetscOptionsHasName(NULL, prefix, "-pc_asm_print_subdomains", &flg));
245: if (flg) PetscCall(PCASMPrintSubdomains(pc));
246: if (!osm->ksp) {
247: /* Create the local solvers */
248: PetscCall(PetscMalloc1(osm->n_local_true, &osm->ksp));
249: if (domain_dm) PetscCall(PetscInfo(pc, "Setting up ASM subproblems using the embedded DM\n"));
250: for (i = 0; i < osm->n_local_true; i++) {
251: PetscCall(KSPCreate(PETSC_COMM_SELF, &ksp));
252: PetscCall(KSPSetNestLevel(ksp, pc->kspnestlevel));
253: PetscCall(KSPSetErrorIfNotConverged(ksp, pc->erroriffailure));
254: PetscCall(PetscObjectIncrementTabLevel((PetscObject)ksp, (PetscObject)pc, 1));
255: PetscCall(KSPSetType(ksp, KSPPREONLY));
256: PetscCall(KSPGetPC(ksp, &subpc));
257: PetscCall(PCGetOptionsPrefix(pc, &prefix));
258: PetscCall(KSPSetOptionsPrefix(ksp, prefix));
259: PetscCall(KSPAppendOptionsPrefix(ksp, "sub_"));
260: if (domain_dm) {
261: PetscCall(KSPSetDM(ksp, domain_dm[i]));
262: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
263: PetscCall(DMDestroy(&domain_dm[i]));
264: }
265: osm->ksp[i] = ksp;
266: }
267: if (domain_dm) PetscCall(PetscFree(domain_dm));
268: }
270: PetscCall(ISConcatenate(PETSC_COMM_SELF, osm->n_local_true, osm->is, &osm->lis));
271: PetscCall(ISSortRemoveDups(osm->lis));
272: PetscCall(ISGetLocalSize(osm->lis, &m));
274: scall = MAT_INITIAL_MATRIX;
275: } else {
276: /*
277: Destroy the blocks from the previous iteration
278: */
279: if (pc->flag == DIFFERENT_NONZERO_PATTERN) {
280: PetscCall(MatGetNullSpaces(osm->n_local_true, osm->pmat, &nullsp));
281: PetscCall(MatDestroyMatrices(osm->n_local_true, &osm->pmat));
282: scall = MAT_INITIAL_MATRIX;
283: }
284: }
286: /* Destroy previous submatrices of a different type than pc->pmat since MAT_REUSE_MATRIX won't work in that case */
287: if (scall == MAT_REUSE_MATRIX && osm->sub_mat_type) {
288: PetscCall(MatGetNullSpaces(osm->n_local_true, osm->pmat, &nullsp));
289: if (osm->n_local_true > 0) PetscCall(MatDestroySubMatrices(osm->n_local_true, &osm->pmat));
290: scall = MAT_INITIAL_MATRIX;
291: }
293: /*
294: Extract out the submatrices
295: */
296: PetscCall(MatCreateSubMatrices(pc->pmat, osm->n_local_true, osm->is, osm->is, scall, &osm->pmat));
297: if (scall == MAT_INITIAL_MATRIX) {
298: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)pc->pmat, &pprefix));
299: for (i = 0; i < osm->n_local_true; i++) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)osm->pmat[i], pprefix));
300: if (nullsp) PetscCall(MatRestoreNullSpaces(osm->n_local_true, osm->pmat, &nullsp));
301: }
303: /* Convert the types of the submatrices (if needbe) */
304: if (osm->sub_mat_type) {
305: for (i = 0; i < osm->n_local_true; i++) PetscCall(MatConvert(osm->pmat[i], osm->sub_mat_type, MAT_INPLACE_MATRIX, &osm->pmat[i]));
306: }
308: if (!pc->setupcalled) {
309: VecType vtype;
311: /* Create the local work vectors (from the local matrices) and scatter contexts */
312: PetscCall(MatCreateVecs(pc->pmat, &vec, NULL));
314: PetscCheck(!osm->is_local || osm->n_local_true == 1 || (osm->type != PC_ASM_INTERPOLATE && osm->type != PC_ASM_NONE), PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Cannot use interpolate or none PCASMType if is_local was provided to PCASMSetLocalSubdomains() with more than a single subdomain");
315: if (osm->is_local && osm->type != PC_ASM_BASIC && osm->loctype == PC_COMPOSITE_ADDITIVE) PetscCall(PetscMalloc1(osm->n_local_true, &osm->lprolongation));
316: PetscCall(PetscMalloc1(osm->n_local_true, &osm->lrestriction));
317: PetscCall(PetscMalloc1(osm->n_local_true, &osm->x));
318: PetscCall(PetscMalloc1(osm->n_local_true, &osm->y));
320: PetscCall(ISGetLocalSize(osm->lis, &m));
321: PetscCall(ISCreateStride(PETSC_COMM_SELF, m, 0, 1, &isl));
322: PetscCall(MatGetVecType(osm->pmat[0], &vtype));
323: PetscCall(VecCreate(PETSC_COMM_SELF, &osm->lx));
324: PetscCall(VecSetSizes(osm->lx, m, m));
325: PetscCall(VecSetType(osm->lx, vtype));
326: PetscCall(VecDuplicate(osm->lx, &osm->ly));
327: PetscCall(VecScatterCreate(vec, osm->lis, osm->lx, isl, &osm->restriction));
328: PetscCall(ISDestroy(&isl));
330: for (i = 0; i < osm->n_local_true; ++i) {
331: ISLocalToGlobalMapping ltog;
332: IS isll;
333: const PetscInt *idx_is;
334: PetscInt *idx_lis, nout;
336: PetscCall(ISGetLocalSize(osm->is[i], &m));
337: PetscCall(MatCreateVecs(osm->pmat[i], &osm->x[i], NULL));
338: PetscCall(VecDuplicate(osm->x[i], &osm->y[i]));
340: /* generate a scatter from ly to y[i] picking all the overlapping is[i] entries */
341: PetscCall(ISLocalToGlobalMappingCreateIS(osm->lis, <og));
342: PetscCall(ISGetLocalSize(osm->is[i], &m));
343: PetscCall(ISGetIndices(osm->is[i], &idx_is));
344: PetscCall(PetscMalloc1(m, &idx_lis));
345: PetscCall(ISGlobalToLocalMappingApply(ltog, IS_GTOLM_DROP, m, idx_is, &nout, idx_lis));
346: PetscCheck(nout == m, PETSC_COMM_SELF, PETSC_ERR_PLIB, "is not a subset of lis");
347: PetscCall(ISRestoreIndices(osm->is[i], &idx_is));
348: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m, idx_lis, PETSC_OWN_POINTER, &isll));
349: PetscCall(ISLocalToGlobalMappingDestroy(<og));
350: PetscCall(ISCreateStride(PETSC_COMM_SELF, m, 0, 1, &isl));
351: PetscCall(VecScatterCreate(osm->ly, isll, osm->y[i], isl, &osm->lrestriction[i]));
352: PetscCall(ISDestroy(&isll));
353: PetscCall(ISDestroy(&isl));
354: if (osm->lprolongation) { /* generate a scatter from y[i] to ly picking only the non-overlapping is_local[i] entries */
355: ISLocalToGlobalMapping ltog;
356: IS isll, isll_local;
357: const PetscInt *idx_local;
358: PetscInt *idx1, *idx2, nout;
360: PetscCall(ISGetLocalSize(osm->is_local[i], &m_local));
361: PetscCall(ISGetIndices(osm->is_local[i], &idx_local));
363: PetscCall(ISLocalToGlobalMappingCreateIS(osm->is[i], <og));
364: PetscCall(PetscMalloc1(m_local, &idx1));
365: PetscCall(ISGlobalToLocalMappingApply(ltog, IS_GTOLM_DROP, m_local, idx_local, &nout, idx1));
366: PetscCall(ISLocalToGlobalMappingDestroy(<og));
367: PetscCheck(nout == m_local, PETSC_COMM_SELF, PETSC_ERR_PLIB, "is_local not a subset of is");
368: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m_local, idx1, PETSC_OWN_POINTER, &isll));
370: PetscCall(ISLocalToGlobalMappingCreateIS(osm->lis, <og));
371: PetscCall(PetscMalloc1(m_local, &idx2));
372: PetscCall(ISGlobalToLocalMappingApply(ltog, IS_GTOLM_DROP, m_local, idx_local, &nout, idx2));
373: PetscCall(ISLocalToGlobalMappingDestroy(<og));
374: PetscCheck(nout == m_local, PETSC_COMM_SELF, PETSC_ERR_PLIB, "is_local not a subset of lis");
375: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m_local, idx2, PETSC_OWN_POINTER, &isll_local));
377: PetscCall(ISRestoreIndices(osm->is_local[i], &idx_local));
378: PetscCall(VecScatterCreate(osm->y[i], isll, osm->ly, isll_local, &osm->lprolongation[i]));
380: PetscCall(ISDestroy(&isll));
381: PetscCall(ISDestroy(&isll_local));
382: }
383: }
384: PetscCall(VecDestroy(&vec));
385: }
387: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) {
388: IS *cis;
389: PetscInt c;
391: PetscCall(PetscMalloc1(osm->n_local_true, &cis));
392: for (c = 0; c < osm->n_local_true; ++c) cis[c] = osm->lis;
393: PetscCall(MatCreateSubMatrices(pc->pmat, osm->n_local_true, osm->is, cis, scall, &osm->lmats));
394: PetscCall(PetscFree(cis));
395: }
397: /* Return control to the user so that the submatrices can be modified (e.g., to apply
398: different boundary conditions for the submatrices than for the global problem) */
399: PetscCall(PCModifySubMatrices(pc, osm->n_local_true, osm->is, osm->is, osm->pmat, pc->modifysubmatricesP));
401: /*
402: Loop over subdomains putting them into local ksp
403: */
404: PetscCall(KSPGetOptionsPrefix(osm->ksp[0], &prefix));
405: for (i = 0; i < osm->n_local_true; i++) {
406: PetscCall(KSPSetOperators(osm->ksp[i], osm->pmat[i], osm->pmat[i]));
407: PetscCall(MatSetOptionsPrefix(osm->pmat[i], prefix));
408: if (!pc->setupcalled) PetscCall(KSPSetFromOptions(osm->ksp[i]));
409: }
410: PetscFunctionReturn(PETSC_SUCCESS);
411: }
413: static PetscErrorCode PCSetUpOnBlocks_ASM(PC pc)
414: {
415: PC_ASM *osm = (PC_ASM *)pc->data;
416: PetscInt i;
417: KSPConvergedReason reason;
419: PetscFunctionBegin;
420: for (i = 0; i < osm->n_local_true; i++) {
421: PetscCall(KSPSetUp(osm->ksp[i]));
422: PetscCall(KSPGetConvergedReason(osm->ksp[i], &reason));
423: if (reason == KSP_DIVERGED_PC_FAILED) pc->failedreason = PC_SUBPC_ERROR;
424: }
425: PetscFunctionReturn(PETSC_SUCCESS);
426: }
428: static PetscErrorCode PCApply_ASM(PC pc, Vec x, Vec y)
429: {
430: PC_ASM *osm = (PC_ASM *)pc->data;
431: PetscInt i, n_local_true = osm->n_local_true;
432: ScatterMode forward = SCATTER_FORWARD, reverse = SCATTER_REVERSE;
434: PetscFunctionBegin;
435: /*
436: support for limiting the restriction or interpolation to only local
437: subdomain values (leaving the other values 0).
438: */
439: if (!(osm->type & PC_ASM_RESTRICT)) {
440: forward = SCATTER_FORWARD_LOCAL;
441: /* have to zero the work RHS since scatter may leave some slots empty */
442: PetscCall(VecSet(osm->lx, 0.0));
443: }
444: if (!(osm->type & PC_ASM_INTERPOLATE)) reverse = SCATTER_REVERSE_LOCAL;
446: PetscCheck(osm->loctype == PC_COMPOSITE_MULTIPLICATIVE || osm->loctype == PC_COMPOSITE_ADDITIVE, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Invalid local composition type: %s", PCCompositeTypes[osm->loctype]);
447: /* zero the global and the local solutions */
448: PetscCall(VecSet(y, 0.0));
449: PetscCall(VecSet(osm->ly, 0.0));
451: /* copy the global RHS to local RHS including the ghost nodes */
452: PetscCall(VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
453: PetscCall(VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
455: /* restrict local RHS to the overlapping 0-block RHS */
456: PetscCall(VecScatterBegin(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
457: PetscCall(VecScatterEnd(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
459: /* do the local solves */
460: for (i = 0; i < n_local_true; ++i) {
461: /* solve the overlapping i-block */
462: PetscCall(PetscLogEventBegin(PC_ApplyOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
463: PetscCall(KSPSolve(osm->ksp[i], osm->x[i], osm->y[i]));
464: PetscCall(KSPCheckSolve(osm->ksp[i], pc, osm->y[i]));
465: PetscCall(PetscLogEventEnd(PC_ApplyOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
467: if (osm->lprolongation && osm->type != PC_ASM_INTERPOLATE) { /* interpolate the non-overlapping i-block solution to the local solution (only for restrictive additive) */
468: PetscCall(VecScatterBegin(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
469: PetscCall(VecScatterEnd(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
470: } else { /* interpolate the overlapping i-block solution to the local solution */
471: PetscCall(VecScatterBegin(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
472: PetscCall(VecScatterEnd(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
473: }
475: if (i < n_local_true - 1) {
476: /* restrict local RHS to the overlapping (i+1)-block RHS */
477: PetscCall(VecScatterBegin(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
478: PetscCall(VecScatterEnd(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
480: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) {
481: /* update the overlapping (i+1)-block RHS using the current local solution */
482: PetscCall(MatMult(osm->lmats[i + 1], osm->ly, osm->y[i + 1]));
483: PetscCall(VecAXPBY(osm->x[i + 1], -1., 1., osm->y[i + 1]));
484: }
485: }
486: }
487: /* add the local solution to the global solution including the ghost nodes */
488: PetscCall(VecScatterBegin(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
489: PetscCall(VecScatterEnd(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
490: PetscFunctionReturn(PETSC_SUCCESS);
491: }
493: static PetscErrorCode PCMatApply_ASM(PC pc, Mat X, Mat Y)
494: {
495: PC_ASM *osm = (PC_ASM *)pc->data;
496: Mat Z, W;
497: Vec x;
498: PetscInt i, m, N;
499: ScatterMode forward = SCATTER_FORWARD, reverse = SCATTER_REVERSE;
501: PetscFunctionBegin;
502: PetscCheck(osm->n_local_true <= 1, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Not yet implemented");
503: /*
504: support for limiting the restriction or interpolation to only local
505: subdomain values (leaving the other values 0).
506: */
507: if (!(osm->type & PC_ASM_RESTRICT)) {
508: forward = SCATTER_FORWARD_LOCAL;
509: /* have to zero the work RHS since scatter may leave some slots empty */
510: PetscCall(VecSet(osm->lx, 0.0));
511: }
512: if (!(osm->type & PC_ASM_INTERPOLATE)) reverse = SCATTER_REVERSE_LOCAL;
513: PetscCall(VecGetLocalSize(osm->x[0], &m));
514: PetscCall(MatGetSize(X, NULL, &N));
515: PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, m, N, NULL, &Z));
517: PetscCheck(osm->loctype == PC_COMPOSITE_MULTIPLICATIVE || osm->loctype == PC_COMPOSITE_ADDITIVE, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Invalid local composition type: %s", PCCompositeTypes[osm->loctype]);
518: /* zero the global and the local solutions */
519: PetscCall(MatZeroEntries(Y));
520: PetscCall(VecSet(osm->ly, 0.0));
522: for (i = 0; i < N; ++i) {
523: PetscCall(MatDenseGetColumnVecRead(X, i, &x));
524: /* copy the global RHS to local RHS including the ghost nodes */
525: PetscCall(VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
526: PetscCall(VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
527: PetscCall(MatDenseRestoreColumnVecRead(X, i, &x));
529: PetscCall(MatDenseGetColumnVecWrite(Z, i, &x));
530: /* restrict local RHS to the overlapping 0-block RHS */
531: PetscCall(VecScatterBegin(osm->lrestriction[0], osm->lx, x, INSERT_VALUES, forward));
532: PetscCall(VecScatterEnd(osm->lrestriction[0], osm->lx, x, INSERT_VALUES, forward));
533: PetscCall(MatDenseRestoreColumnVecWrite(Z, i, &x));
534: }
535: PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, m, N, NULL, &W));
536: /* solve the overlapping 0-block */
537: PetscCall(PetscLogEventBegin(PC_ApplyOnBlocks, osm->ksp[0], Z, W, 0));
538: PetscCall(KSPMatSolve(osm->ksp[0], Z, W));
539: PetscCall(KSPCheckSolve(osm->ksp[0], pc, NULL));
540: PetscCall(PetscLogEventEnd(PC_ApplyOnBlocks, osm->ksp[0], Z, W, 0));
541: PetscCall(MatDestroy(&Z));
543: for (i = 0; i < N; ++i) {
544: PetscCall(VecSet(osm->ly, 0.0));
545: PetscCall(MatDenseGetColumnVecRead(W, i, &x));
546: if (osm->lprolongation && osm->type != PC_ASM_INTERPOLATE) { /* interpolate the non-overlapping 0-block solution to the local solution (only for restrictive additive) */
547: PetscCall(VecScatterBegin(osm->lprolongation[0], x, osm->ly, ADD_VALUES, forward));
548: PetscCall(VecScatterEnd(osm->lprolongation[0], x, osm->ly, ADD_VALUES, forward));
549: } else { /* interpolate the overlapping 0-block solution to the local solution */
550: PetscCall(VecScatterBegin(osm->lrestriction[0], x, osm->ly, ADD_VALUES, reverse));
551: PetscCall(VecScatterEnd(osm->lrestriction[0], x, osm->ly, ADD_VALUES, reverse));
552: }
553: PetscCall(MatDenseRestoreColumnVecRead(W, i, &x));
555: PetscCall(MatDenseGetColumnVecWrite(Y, i, &x));
556: /* add the local solution to the global solution including the ghost nodes */
557: PetscCall(VecScatterBegin(osm->restriction, osm->ly, x, ADD_VALUES, reverse));
558: PetscCall(VecScatterEnd(osm->restriction, osm->ly, x, ADD_VALUES, reverse));
559: PetscCall(MatDenseRestoreColumnVecWrite(Y, i, &x));
560: }
561: PetscCall(MatDestroy(&W));
562: PetscFunctionReturn(PETSC_SUCCESS);
563: }
565: static PetscErrorCode PCApplyTranspose_ASM(PC pc, Vec x, Vec y)
566: {
567: PC_ASM *osm = (PC_ASM *)pc->data;
568: PetscInt i, n_local_true = osm->n_local_true;
569: ScatterMode forward = SCATTER_FORWARD, reverse = SCATTER_REVERSE;
571: PetscFunctionBegin;
572: PetscCheck(osm->n_local_true <= 1 || osm->loctype == PC_COMPOSITE_ADDITIVE, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Not yet implemented");
573: /*
574: Support for limiting the restriction or interpolation to only local
575: subdomain values (leaving the other values 0).
577: Note: these are reversed from the PCApply_ASM() because we are applying the
578: transpose of the three terms
579: */
581: if (!(osm->type & PC_ASM_INTERPOLATE)) {
582: forward = SCATTER_FORWARD_LOCAL;
583: /* have to zero the work RHS since scatter may leave some slots empty */
584: PetscCall(VecSet(osm->lx, 0.0));
585: }
586: if (!(osm->type & PC_ASM_RESTRICT)) reverse = SCATTER_REVERSE_LOCAL;
588: /* zero the global and the local solutions */
589: PetscCall(VecSet(y, 0.0));
590: PetscCall(VecSet(osm->ly, 0.0));
592: /* Copy the global RHS to local RHS including the ghost nodes */
593: PetscCall(VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
594: PetscCall(VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
596: /* Restrict local RHS to the overlapping 0-block RHS */
597: PetscCall(VecScatterBegin(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
598: PetscCall(VecScatterEnd(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
600: /* do the local solves */
601: for (i = 0; i < n_local_true; ++i) {
602: /* solve the overlapping i-block */
603: PetscCall(PetscLogEventBegin(PC_ApplyTransposeOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
604: PetscCall(KSPSolveTranspose(osm->ksp[i], osm->x[i], osm->y[i]));
605: PetscCall(KSPCheckSolve(osm->ksp[i], pc, osm->y[i]));
606: PetscCall(PetscLogEventEnd(PC_ApplyTransposeOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
608: if (osm->lprolongation && osm->type != PC_ASM_RESTRICT) { /* interpolate the non-overlapping i-block solution to the local solution */
609: PetscCall(VecScatterBegin(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
610: PetscCall(VecScatterEnd(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
611: } else { /* interpolate the overlapping i-block solution to the local solution */
612: PetscCall(VecScatterBegin(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
613: PetscCall(VecScatterEnd(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
614: }
616: if (i < n_local_true - 1) {
617: /* Restrict local RHS to the overlapping (i+1)-block RHS */
618: PetscCall(VecScatterBegin(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
619: PetscCall(VecScatterEnd(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
620: }
621: }
622: /* Add the local solution to the global solution including the ghost nodes */
623: PetscCall(VecScatterBegin(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
624: PetscCall(VecScatterEnd(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
625: PetscFunctionReturn(PETSC_SUCCESS);
626: }
628: static PetscErrorCode PCReset_ASM(PC pc)
629: {
630: PC_ASM *osm = (PC_ASM *)pc->data;
631: PetscInt i;
633: PetscFunctionBegin;
634: if (osm->ksp) {
635: for (i = 0; i < osm->n_local_true; i++) PetscCall(KSPReset(osm->ksp[i]));
636: }
637: if (osm->pmat) {
638: if (osm->n_local_true > 0) PetscCall(MatDestroySubMatrices(osm->n_local_true, &osm->pmat));
639: }
640: if (osm->lrestriction) {
641: PetscCall(VecScatterDestroy(&osm->restriction));
642: for (i = 0; i < osm->n_local_true; i++) {
643: PetscCall(VecScatterDestroy(&osm->lrestriction[i]));
644: if (osm->lprolongation) PetscCall(VecScatterDestroy(&osm->lprolongation[i]));
645: PetscCall(VecDestroy(&osm->x[i]));
646: PetscCall(VecDestroy(&osm->y[i]));
647: }
648: PetscCall(PetscFree(osm->lrestriction));
649: if (osm->lprolongation) PetscCall(PetscFree(osm->lprolongation));
650: PetscCall(PetscFree(osm->x));
651: PetscCall(PetscFree(osm->y));
652: }
653: PetscCall(PCASMDestroySubdomains(osm->n_local_true, &osm->is, &osm->is_local));
654: PetscCall(ISDestroy(&osm->lis));
655: PetscCall(VecDestroy(&osm->lx));
656: PetscCall(VecDestroy(&osm->ly));
657: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) PetscCall(MatDestroyMatrices(osm->n_local_true, &osm->lmats));
659: PetscCall(PetscFree(osm->sub_mat_type));
661: osm->is = NULL;
662: osm->is_local = NULL;
663: PetscFunctionReturn(PETSC_SUCCESS);
664: }
666: static PetscErrorCode PCDestroy_ASM(PC pc)
667: {
668: PC_ASM *osm = (PC_ASM *)pc->data;
669: PetscInt i;
671: PetscFunctionBegin;
672: PetscCall(PCReset_ASM(pc));
673: if (osm->ksp) {
674: for (i = 0; i < osm->n_local_true; i++) PetscCall(KSPDestroy(&osm->ksp[i]));
675: PetscCall(PetscFree(osm->ksp));
676: }
677: PetscCall(PetscFree(pc->data));
679: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalSubdomains_C", NULL));
680: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetTotalSubdomains_C", NULL));
681: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetOverlap_C", NULL));
682: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetType_C", NULL));
683: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetType_C", NULL));
684: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalType_C", NULL));
685: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetLocalType_C", NULL));
686: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSortIndices_C", NULL));
687: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubKSP_C", NULL));
688: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubMatType_C", NULL));
689: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSubMatType_C", NULL));
690: PetscFunctionReturn(PETSC_SUCCESS);
691: }
693: static PetscErrorCode PCSetFromOptions_ASM(PC pc, PetscOptionItems PetscOptionsObject)
694: {
695: PC_ASM *osm = (PC_ASM *)pc->data;
696: PetscInt blocks, ovl;
697: PetscBool flg;
698: PCASMType asmtype;
699: PCCompositeType loctype;
700: char sub_mat_type[256];
702: PetscFunctionBegin;
703: PetscOptionsHeadBegin(PetscOptionsObject, "Additive Schwarz options");
704: PetscCall(PetscOptionsBool("-pc_asm_dm_subdomains", "Use DMCreateDomainDecomposition() to define subdomains", "PCASMSetDMSubdomains", osm->dm_subdomains, &osm->dm_subdomains, &flg));
705: PetscCall(PetscOptionsInt("-pc_asm_blocks", "Number of subdomains", "PCASMSetTotalSubdomains", osm->n, &blocks, &flg));
706: if (flg) {
707: PetscCall(PCASMSetTotalSubdomains(pc, blocks, NULL, NULL));
708: osm->dm_subdomains = PETSC_FALSE;
709: }
710: PetscCall(PetscOptionsInt("-pc_asm_local_blocks", "Number of local subdomains", "PCASMSetLocalSubdomains", osm->n_local_true, &blocks, &flg));
711: if (flg) {
712: PetscCall(PCASMSetLocalSubdomains(pc, blocks, NULL, NULL));
713: osm->dm_subdomains = PETSC_FALSE;
714: }
715: PetscCall(PetscOptionsInt("-pc_asm_overlap", "Number of grid points overlap", "PCASMSetOverlap", osm->overlap, &ovl, &flg));
716: if (flg) {
717: PetscCall(PCASMSetOverlap(pc, ovl));
718: osm->dm_subdomains = PETSC_FALSE;
719: }
720: flg = PETSC_FALSE;
721: PetscCall(PetscOptionsEnum("-pc_asm_type", "Type of restriction/extension", "PCASMSetType", PCASMTypes, (PetscEnum)osm->type, (PetscEnum *)&asmtype, &flg));
722: if (flg) PetscCall(PCASMSetType(pc, asmtype));
723: flg = PETSC_FALSE;
724: PetscCall(PetscOptionsEnum("-pc_asm_local_type", "Type of local solver composition", "PCASMSetLocalType", PCCompositeTypes, (PetscEnum)osm->loctype, (PetscEnum *)&loctype, &flg));
725: if (flg) PetscCall(PCASMSetLocalType(pc, loctype));
726: PetscCall(PetscOptionsFList("-pc_asm_sub_mat_type", "Subsolve Matrix Type", "PCASMSetSubMatType", MatList, NULL, sub_mat_type, 256, &flg));
727: if (flg) PetscCall(PCASMSetSubMatType(pc, sub_mat_type));
728: PetscOptionsHeadEnd();
729: PetscFunctionReturn(PETSC_SUCCESS);
730: }
732: static PetscErrorCode PCASMSetLocalSubdomains_ASM(PC pc, PetscInt n, IS is[], IS is_local[])
733: {
734: PC_ASM *osm = (PC_ASM *)pc->data;
735: PetscInt i;
737: PetscFunctionBegin;
738: PetscCheck(n >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Each process must have 1 or more blocks, n = %" PetscInt_FMT, n);
739: PetscCheck(!pc->setupcalled || (n == osm->n_local_true && !is), PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONGSTATE, "PCASMSetLocalSubdomains() should be called before calling PCSetUp().");
741: if (!pc->setupcalled) {
742: if (is) {
743: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)is[i]));
744: }
745: if (is_local) {
746: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)is_local[i]));
747: }
748: PetscCall(PCASMDestroySubdomains(osm->n_local_true, &osm->is, &osm->is_local));
750: if (osm->ksp && osm->n_local_true != n) {
751: for (i = 0; i < osm->n_local_true; i++) PetscCall(KSPDestroy(&osm->ksp[i]));
752: PetscCall(PetscFree(osm->ksp));
753: }
755: osm->n_local_true = n;
756: osm->is = NULL;
757: osm->is_local = NULL;
758: if (is) {
759: PetscCall(PetscMalloc1(n, &osm->is));
760: for (i = 0; i < n; i++) osm->is[i] = is[i];
761: /* Flag indicating that the user has set overlapping subdomains so PCASM should not increase their size. */
762: osm->overlap = -1;
763: }
764: if (is_local) {
765: PetscCall(PetscMalloc1(n, &osm->is_local));
766: for (i = 0; i < n; i++) osm->is_local[i] = is_local[i];
767: if (!is) {
768: PetscCall(PetscMalloc1(osm->n_local_true, &osm->is));
769: for (i = 0; i < osm->n_local_true; i++) {
770: if (osm->overlap > 0) { /* With positive overlap, osm->is[i] will be modified */
771: PetscCall(ISDuplicate(osm->is_local[i], &osm->is[i]));
772: PetscCall(ISCopy(osm->is_local[i], osm->is[i]));
773: } else {
774: PetscCall(PetscObjectReference((PetscObject)osm->is_local[i]));
775: osm->is[i] = osm->is_local[i];
776: }
777: }
778: }
779: }
780: }
781: PetscFunctionReturn(PETSC_SUCCESS);
782: }
784: static PetscErrorCode PCASMSetTotalSubdomains_ASM(PC pc, PetscInt N, IS *is, IS *is_local)
785: {
786: PC_ASM *osm = (PC_ASM *)pc->data;
787: PetscMPIInt rank, size;
788: PetscInt n;
790: PetscFunctionBegin;
791: PetscCheck(N >= 1, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_OUTOFRANGE, "Number of total blocks must be > 0, N = %" PetscInt_FMT, N);
792: PetscCheck(!is && !is_local, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Use PCASMSetLocalSubdomains() to set specific index sets, they cannot be set globally yet.");
794: /*
795: Split the subdomains equally among all processors
796: */
797: PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank));
798: PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size));
799: n = N / size + ((N % size) > rank);
800: PetscCheck(n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Process %d must have at least one block: total processors %d total blocks %" PetscInt_FMT, rank, size, N);
801: PetscCheck(!pc->setupcalled || n == osm->n_local_true, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "PCASMSetTotalSubdomains() should be called before PCSetUp().");
802: if (!pc->setupcalled) {
803: PetscCall(PCASMDestroySubdomains(osm->n_local_true, &osm->is, &osm->is_local));
805: osm->n_local_true = n;
806: osm->is = NULL;
807: osm->is_local = NULL;
808: }
809: PetscFunctionReturn(PETSC_SUCCESS);
810: }
812: static PetscErrorCode PCASMSetOverlap_ASM(PC pc, PetscInt ovl)
813: {
814: PC_ASM *osm = (PC_ASM *)pc->data;
816: PetscFunctionBegin;
817: PetscCheck(ovl >= 0, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_OUTOFRANGE, "Negative overlap value requested");
818: PetscCheck(!pc->setupcalled || ovl == osm->overlap, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONGSTATE, "PCASMSetOverlap() should be called before PCSetUp().");
819: if (!pc->setupcalled) osm->overlap = ovl;
820: PetscFunctionReturn(PETSC_SUCCESS);
821: }
823: static PetscErrorCode PCASMSetType_ASM(PC pc, PCASMType type)
824: {
825: PC_ASM *osm = (PC_ASM *)pc->data;
827: PetscFunctionBegin;
828: osm->type = type;
829: osm->type_set = PETSC_TRUE;
830: PetscFunctionReturn(PETSC_SUCCESS);
831: }
833: static PetscErrorCode PCASMGetType_ASM(PC pc, PCASMType *type)
834: {
835: PC_ASM *osm = (PC_ASM *)pc->data;
837: PetscFunctionBegin;
838: *type = osm->type;
839: PetscFunctionReturn(PETSC_SUCCESS);
840: }
842: static PetscErrorCode PCASMSetLocalType_ASM(PC pc, PCCompositeType type)
843: {
844: PC_ASM *osm = (PC_ASM *)pc->data;
846: PetscFunctionBegin;
847: PetscCheck(type == PC_COMPOSITE_ADDITIVE || type == PC_COMPOSITE_MULTIPLICATIVE, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Only supports additive or multiplicative as the local type");
848: osm->loctype = type;
849: PetscFunctionReturn(PETSC_SUCCESS);
850: }
852: static PetscErrorCode PCASMGetLocalType_ASM(PC pc, PCCompositeType *type)
853: {
854: PC_ASM *osm = (PC_ASM *)pc->data;
856: PetscFunctionBegin;
857: *type = osm->loctype;
858: PetscFunctionReturn(PETSC_SUCCESS);
859: }
861: static PetscErrorCode PCASMSetSortIndices_ASM(PC pc, PetscBool doSort)
862: {
863: PC_ASM *osm = (PC_ASM *)pc->data;
865: PetscFunctionBegin;
866: osm->sort_indices = doSort;
867: PetscFunctionReturn(PETSC_SUCCESS);
868: }
870: static PetscErrorCode PCASMGetSubKSP_ASM(PC pc, PetscInt *n_local, PetscInt *first_local, KSP **ksp)
871: {
872: PC_ASM *osm = (PC_ASM *)pc->data;
874: PetscFunctionBegin;
875: PetscCheck(osm->n_local_true >= 1, PetscObjectComm((PetscObject)pc), PETSC_ERR_ORDER, "Need to call PCSetUp() on PC (or KSPSetUp() on the outer KSP object) before calling here");
877: if (n_local) *n_local = osm->n_local_true;
878: if (first_local) {
879: PetscCallMPI(MPI_Scan(&osm->n_local_true, first_local, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)pc)));
880: *first_local -= osm->n_local_true;
881: }
882: if (ksp) *ksp = osm->ksp;
883: PetscFunctionReturn(PETSC_SUCCESS);
884: }
886: static PetscErrorCode PCASMGetSubMatType_ASM(PC pc, MatType *sub_mat_type)
887: {
888: PC_ASM *osm = (PC_ASM *)pc->data;
890: PetscFunctionBegin;
892: PetscAssertPointer(sub_mat_type, 2);
893: *sub_mat_type = osm->sub_mat_type;
894: PetscFunctionReturn(PETSC_SUCCESS);
895: }
897: static PetscErrorCode PCASMSetSubMatType_ASM(PC pc, MatType sub_mat_type)
898: {
899: PC_ASM *osm = (PC_ASM *)pc->data;
901: PetscFunctionBegin;
903: PetscCall(PetscFree(osm->sub_mat_type));
904: PetscCall(PetscStrallocpy(sub_mat_type, (char **)&osm->sub_mat_type));
905: PetscFunctionReturn(PETSC_SUCCESS);
906: }
908: /*@
909: PCASMSetLocalSubdomains - Sets the local subdomains (for this processor only) for the additive Schwarz preconditioner `PCASM`.
911: Collective
913: Input Parameters:
914: + pc - the preconditioner context
915: . n - the number of subdomains for this processor (default value = 1)
916: . is - the index set that defines the subdomains for this processor (or `NULL` for PETSc to determine subdomains)
917: the values of the `is` array are copied so you can free the array (not the `IS` in the array) after this call
918: - is_local - the index sets that define the local part of the subdomains for this processor, not used unless `PCASMType` is `PC_ASM_RESTRICT`
919: (or `NULL` to not provide these). The values of the `is_local` array are copied so you can free the array
920: (not the `IS` in the array) after this call
922: Options Database Key:
923: . -pc_asm_local_blocks <blks> - Sets number of local blocks
925: Level: advanced
927: Notes:
928: The `IS` numbering is in the parallel, global numbering of the vector for both `is` and `is_local`
930: By default the `PCASM` preconditioner uses 1 block per processor.
932: Use `PCASMSetTotalSubdomains()` to set the subdomains for all processors.
934: If `is_local` is provided and `PCASMType` is `PC_ASM_RESTRICT` then the solution only over the `is_local` region is interpolated
935: back to form the global solution (this is the standard restricted additive Schwarz method, RASM)
937: If `is_local` is provided and `PCASMType` is `PC_ASM_INTERPOLATE` or `PC_ASM_NONE` then an error is generated since there is
938: no code to handle that case.
940: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
941: `PCASMCreateSubdomains2D()`, `PCASMGetLocalSubdomains()`, `PCASMType`, `PCASMSetType()`, `PCGASM`
942: @*/
943: PetscErrorCode PCASMSetLocalSubdomains(PC pc, PetscInt n, IS is[], IS is_local[])
944: {
945: PetscFunctionBegin;
947: PetscTryMethod(pc, "PCASMSetLocalSubdomains_C", (PC, PetscInt, IS[], IS[]), (pc, n, is, is_local));
948: PetscFunctionReturn(PETSC_SUCCESS);
949: }
951: /*@
952: PCASMSetTotalSubdomains - Sets the subdomains for all processors for the
953: additive Schwarz preconditioner, `PCASM`.
955: Collective, all MPI ranks must pass in the same array of `IS`
957: Input Parameters:
958: + pc - the preconditioner context
959: . N - the number of subdomains for all processors
960: . is - the index sets that define the subdomains for all processors (or `NULL` to ask PETSc to determine the subdomains)
961: the values of the `is` array are copied so you can free the array (not the `IS` in the array) after this call
962: - is_local - the index sets that define the local part of the subdomains for this processor (or `NULL` to not provide this information)
963: The values of the `is_local` array are copied so you can free the array (not the `IS` in the array) after this call
965: Options Database Key:
966: . -pc_asm_blocks <blks> - Sets total blocks
968: Level: advanced
970: Notes:
971: Currently you cannot use this to set the actual subdomains with the argument `is` or `is_local`.
973: By default the `PCASM` preconditioner uses 1 block per processor.
975: These index sets cannot be destroyed until after completion of the
976: linear solves for which the `PCASM` preconditioner is being used.
978: Use `PCASMSetLocalSubdomains()` to set local subdomains.
980: The `IS` numbering is in the parallel, global numbering of the vector for both is and is_local
982: .seealso: [](ch_ksp), `PCASM`, `PCASMSetLocalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
983: `PCASMCreateSubdomains2D()`, `PCGASM`
984: @*/
985: PetscErrorCode PCASMSetTotalSubdomains(PC pc, PetscInt N, IS is[], IS is_local[])
986: {
987: PetscFunctionBegin;
989: PetscTryMethod(pc, "PCASMSetTotalSubdomains_C", (PC, PetscInt, IS[], IS[]), (pc, N, is, is_local));
990: PetscFunctionReturn(PETSC_SUCCESS);
991: }
993: /*@
994: PCASMSetOverlap - Sets the overlap between a pair of subdomains for the
995: additive Schwarz preconditioner, `PCASM`.
997: Logically Collective
999: Input Parameters:
1000: + pc - the preconditioner context
1001: - ovl - the amount of overlap between subdomains (ovl >= 0, default value = 1)
1003: Options Database Key:
1004: . -pc_asm_overlap <ovl> - Sets overlap
1006: Level: intermediate
1008: Notes:
1009: By default the `PCASM` preconditioner uses 1 block per processor. To use
1010: multiple blocks per perocessor, see `PCASMSetTotalSubdomains()` and
1011: `PCASMSetLocalSubdomains()` (and the option -pc_asm_blocks <blks>).
1013: The overlap defaults to 1, so if one desires that no additional
1014: overlap be computed beyond what may have been set with a call to
1015: `PCASMSetTotalSubdomains()` or `PCASMSetLocalSubdomains()`, then ovl
1016: must be set to be 0. In particular, if one does not explicitly set
1017: the subdomains an application code, then all overlap would be computed
1018: internally by PETSc, and using an overlap of 0 would result in an `PCASM`
1019: variant that is equivalent to the block Jacobi preconditioner.
1021: The default algorithm used by PETSc to increase overlap is fast, but not scalable,
1022: use the option -mat_increase_overlap_scalable when the problem and number of processes is large.
1024: One can define initial index sets with any overlap via
1025: `PCASMSetLocalSubdomains()`; the routine
1026: `PCASMSetOverlap()` merely allows PETSc to extend that overlap further
1027: if desired.
1029: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetLocalSubdomains()`, `PCASMGetSubKSP()`,
1030: `PCASMCreateSubdomains2D()`, `PCASMGetLocalSubdomains()`, `MatIncreaseOverlap()`, `PCGASM`
1031: @*/
1032: PetscErrorCode PCASMSetOverlap(PC pc, PetscInt ovl)
1033: {
1034: PetscFunctionBegin;
1037: PetscTryMethod(pc, "PCASMSetOverlap_C", (PC, PetscInt), (pc, ovl));
1038: PetscFunctionReturn(PETSC_SUCCESS);
1039: }
1041: /*@
1042: PCASMSetType - Sets the type of restriction and interpolation used
1043: for local problems in the additive Schwarz method, `PCASM`.
1045: Logically Collective
1047: Input Parameters:
1048: + pc - the preconditioner context
1049: - type - variant of `PCASM`, one of
1050: .vb
1051: PC_ASM_BASIC - full interpolation and restriction
1052: PC_ASM_RESTRICT - full restriction, local processor interpolation (default)
1053: PC_ASM_INTERPOLATE - full interpolation, local processor restriction
1054: PC_ASM_NONE - local processor restriction and interpolation
1055: .ve
1057: Options Database Key:
1058: . -pc_asm_type [basic,restrict,interpolate,none] - Sets `PCASMType`
1060: Level: intermediate
1062: Note:
1063: if the is_local arguments are passed to `PCASMSetLocalSubdomains()` then they are used when `PC_ASM_RESTRICT` has been selected
1064: to limit the local processor interpolation
1066: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMGetSubKSP()`,
1067: `PCASMCreateSubdomains2D()`, `PCASMType`, `PCASMSetLocalType()`, `PCASMGetLocalType()`, `PCGASM`
1068: @*/
1069: PetscErrorCode PCASMSetType(PC pc, PCASMType type)
1070: {
1071: PetscFunctionBegin;
1074: PetscTryMethod(pc, "PCASMSetType_C", (PC, PCASMType), (pc, type));
1075: PetscFunctionReturn(PETSC_SUCCESS);
1076: }
1078: /*@
1079: PCASMGetType - Gets the type of restriction and interpolation used
1080: for local problems in the additive Schwarz method, `PCASM`.
1082: Logically Collective
1084: Input Parameter:
1085: . pc - the preconditioner context
1087: Output Parameter:
1088: . type - variant of `PCASM`, one of
1089: .vb
1090: PC_ASM_BASIC - full interpolation and restriction
1091: PC_ASM_RESTRICT - full restriction, local processor interpolation
1092: PC_ASM_INTERPOLATE - full interpolation, local processor restriction
1093: PC_ASM_NONE - local processor restriction and interpolation
1094: .ve
1096: Options Database Key:
1097: . -pc_asm_type [basic,restrict,interpolate,none] - Sets `PCASM` type
1099: Level: intermediate
1101: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMGetSubKSP()`, `PCGASM`,
1102: `PCASMCreateSubdomains2D()`, `PCASMType`, `PCASMSetType()`, `PCASMSetLocalType()`, `PCASMGetLocalType()`
1103: @*/
1104: PetscErrorCode PCASMGetType(PC pc, PCASMType *type)
1105: {
1106: PetscFunctionBegin;
1108: PetscUseMethod(pc, "PCASMGetType_C", (PC, PCASMType *), (pc, type));
1109: PetscFunctionReturn(PETSC_SUCCESS);
1110: }
1112: /*@
1113: PCASMSetLocalType - Sets the type of composition used for local problems in the additive Schwarz method, `PCASM`.
1115: Logically Collective
1117: Input Parameters:
1118: + pc - the preconditioner context
1119: - type - type of composition, one of
1120: .vb
1121: PC_COMPOSITE_ADDITIVE - local additive combination
1122: PC_COMPOSITE_MULTIPLICATIVE - local multiplicative combination
1123: .ve
1125: Options Database Key:
1126: . -pc_asm_local_type [additive,multiplicative] - Sets local solver composition type
1128: Level: intermediate
1130: .seealso: [](ch_ksp), `PCASM`, `PCASMSetType()`, `PCASMGetType()`, `PCASMGetLocalType()`, `PCASMType`, `PCCompositeType`
1131: @*/
1132: PetscErrorCode PCASMSetLocalType(PC pc, PCCompositeType type)
1133: {
1134: PetscFunctionBegin;
1137: PetscTryMethod(pc, "PCASMSetLocalType_C", (PC, PCCompositeType), (pc, type));
1138: PetscFunctionReturn(PETSC_SUCCESS);
1139: }
1141: /*@
1142: PCASMGetLocalType - Gets the type of composition used for local problems in the additive Schwarz method, `PCASM`.
1144: Logically Collective
1146: Input Parameter:
1147: . pc - the preconditioner context
1149: Output Parameter:
1150: . type - type of composition, one of
1151: .vb
1152: PC_COMPOSITE_ADDITIVE - local additive combination
1153: PC_COMPOSITE_MULTIPLICATIVE - local multiplicative combination
1154: .ve
1156: Options Database Key:
1157: . -pc_asm_local_type [additive,multiplicative] - Sets local solver composition type
1159: Level: intermediate
1161: .seealso: [](ch_ksp), `PCASM`, `PCASMSetType()`, `PCASMGetType()`, `PCASMSetLocalType()`, `PCASMType`, `PCCompositeType`
1162: @*/
1163: PetscErrorCode PCASMGetLocalType(PC pc, PCCompositeType *type)
1164: {
1165: PetscFunctionBegin;
1167: PetscAssertPointer(type, 2);
1168: PetscUseMethod(pc, "PCASMGetLocalType_C", (PC, PCCompositeType *), (pc, type));
1169: PetscFunctionReturn(PETSC_SUCCESS);
1170: }
1172: /*@
1173: PCASMSetSortIndices - Determines whether subdomain indices are sorted.
1175: Logically Collective
1177: Input Parameters:
1178: + pc - the preconditioner context
1179: - doSort - sort the subdomain indices
1181: Level: intermediate
1183: .seealso: [](ch_ksp), `PCASM`, `PCASMSetLocalSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMGetSubKSP()`,
1184: `PCASMCreateSubdomains2D()`
1185: @*/
1186: PetscErrorCode PCASMSetSortIndices(PC pc, PetscBool doSort)
1187: {
1188: PetscFunctionBegin;
1191: PetscTryMethod(pc, "PCASMSetSortIndices_C", (PC, PetscBool), (pc, doSort));
1192: PetscFunctionReturn(PETSC_SUCCESS);
1193: }
1195: /*@C
1196: PCASMGetSubKSP - Gets the local `KSP` contexts for all blocks on
1197: this processor.
1199: Collective iff first_local is requested
1201: Input Parameter:
1202: . pc - the preconditioner context
1204: Output Parameters:
1205: + n_local - the number of blocks on this processor or `NULL`
1206: . first_local - the global number of the first block on this processor or `NULL`, all processors must request or all must pass `NULL`
1207: - ksp - the array of `KSP` contexts
1209: Level: advanced
1211: Notes:
1212: After `PCASMGetSubKSP()` the array of `KSP`s is not to be freed.
1214: You must call `KSPSetUp()` before calling `PCASMGetSubKSP()`.
1216: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`,
1217: `PCASMCreateSubdomains2D()`,
1218: @*/
1219: PetscErrorCode PCASMGetSubKSP(PC pc, PetscInt *n_local, PetscInt *first_local, KSP *ksp[])
1220: {
1221: PetscFunctionBegin;
1223: PetscUseMethod(pc, "PCASMGetSubKSP_C", (PC, PetscInt *, PetscInt *, KSP **), (pc, n_local, first_local, ksp));
1224: PetscFunctionReturn(PETSC_SUCCESS);
1225: }
1227: /*MC
1228: PCASM - Use the (restricted) additive Schwarz method, each block is (approximately) solved with
1229: its own `KSP` object, {cite}`dryja1987additive` and {cite}`1sbg`
1231: Options Database Keys:
1232: + -pc_asm_blocks <blks> - Sets total blocks. Defaults to one block per MPI process.
1233: . -pc_asm_overlap <ovl> - Sets overlap
1234: . -pc_asm_type [basic,restrict,interpolate,none] - Sets `PCASMType`, default is restrict. See `PCASMSetType()`
1235: . -pc_asm_dm_subdomains <bool> - use subdomains defined by the `DM` with `DMCreateDomainDecomposition()`
1236: - -pc_asm_local_type [additive, multiplicative] - Sets `PCCompositeType`, default is additive. See `PCASMSetLocalType()`
1238: Level: beginner
1240: Notes:
1241: If you run with, for example, 3 blocks on 1 processor or 3 blocks on 3 processors you
1242: will get a different convergence rate due to the default option of `-pc_asm_type restrict`. Use
1243: `-pc_asm_type basic` to get the same convergence behavior
1245: Each processor can have one or more blocks, but a block cannot be shared by more
1246: than one processor. Use `PCGASM` for subdomains shared by multiple processes.
1248: To set options on the solvers for each block append `-sub_` to all the `KSP`, and `PC`
1249: options database keys. For example, `-sub_pc_type ilu -sub_pc_factor_levels 1 -sub_ksp_type preonly`
1251: To set the options on the solvers separate for each block call `PCASMGetSubKSP()`
1252: and set the options directly on the resulting `KSP` object (you can access its `PC` with `KSPGetPC()`)
1254: If the `PC` has an associated `DM`, then, by default, `DMCreateDomainDecomposition()` is used to create the subdomains
1256: .seealso: [](ch_ksp), `PCCreate()`, `PCSetType()`, `PCType`, `PC`, `PCASMType`, `PCCompositeType`,
1257: `PCBJACOBI`, `PCASMGetSubKSP()`, `PCASMSetLocalSubdomains()`, `PCASMType`, `PCASMGetType()`, `PCASMSetLocalType()`, `PCASMGetLocalType()`
1258: `PCASMSetTotalSubdomains()`, `PCSetModifySubMatrices()`, `PCASMSetOverlap()`, `PCASMSetType()`, `PCCompositeType`
1259: M*/
1261: PETSC_EXTERN PetscErrorCode PCCreate_ASM(PC pc)
1262: {
1263: PC_ASM *osm;
1265: PetscFunctionBegin;
1266: PetscCall(PetscNew(&osm));
1268: osm->n = PETSC_DECIDE;
1269: osm->n_local = 0;
1270: osm->n_local_true = PETSC_DECIDE;
1271: osm->overlap = 1;
1272: osm->ksp = NULL;
1273: osm->restriction = NULL;
1274: osm->lprolongation = NULL;
1275: osm->lrestriction = NULL;
1276: osm->x = NULL;
1277: osm->y = NULL;
1278: osm->is = NULL;
1279: osm->is_local = NULL;
1280: osm->mat = NULL;
1281: osm->pmat = NULL;
1282: osm->type = PC_ASM_RESTRICT;
1283: osm->loctype = PC_COMPOSITE_ADDITIVE;
1284: osm->sort_indices = PETSC_TRUE;
1285: osm->dm_subdomains = PETSC_FALSE;
1286: osm->sub_mat_type = NULL;
1288: pc->data = (void *)osm;
1289: pc->ops->apply = PCApply_ASM;
1290: pc->ops->matapply = PCMatApply_ASM;
1291: pc->ops->applytranspose = PCApplyTranspose_ASM;
1292: pc->ops->setup = PCSetUp_ASM;
1293: pc->ops->reset = PCReset_ASM;
1294: pc->ops->destroy = PCDestroy_ASM;
1295: pc->ops->setfromoptions = PCSetFromOptions_ASM;
1296: pc->ops->setuponblocks = PCSetUpOnBlocks_ASM;
1297: pc->ops->view = PCView_ASM;
1298: pc->ops->applyrichardson = NULL;
1300: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalSubdomains_C", PCASMSetLocalSubdomains_ASM));
1301: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetTotalSubdomains_C", PCASMSetTotalSubdomains_ASM));
1302: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetOverlap_C", PCASMSetOverlap_ASM));
1303: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetType_C", PCASMSetType_ASM));
1304: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetType_C", PCASMGetType_ASM));
1305: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalType_C", PCASMSetLocalType_ASM));
1306: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetLocalType_C", PCASMGetLocalType_ASM));
1307: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSortIndices_C", PCASMSetSortIndices_ASM));
1308: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubKSP_C", PCASMGetSubKSP_ASM));
1309: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubMatType_C", PCASMGetSubMatType_ASM));
1310: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSubMatType_C", PCASMSetSubMatType_ASM));
1311: PetscFunctionReturn(PETSC_SUCCESS);
1312: }
1314: /*@C
1315: PCASMCreateSubdomains - Creates the index sets for the overlapping Schwarz
1316: preconditioner, `PCASM`, for any problem on a general grid.
1318: Collective
1320: Input Parameters:
1321: + A - The global matrix operator
1322: - n - the number of local blocks
1324: Output Parameter:
1325: . outis - the array of index sets defining the subdomains
1327: Level: advanced
1329: Note:
1330: This generates nonoverlapping subdomains; the `PCASM` will generate the overlap
1331: from these if you use `PCASMSetLocalSubdomains()`
1333: .seealso: [](ch_ksp), `PCASM`, `PCASMSetLocalSubdomains()`, `PCASMDestroySubdomains()`
1334: @*/
1335: PetscErrorCode PCASMCreateSubdomains(Mat A, PetscInt n, IS *outis[])
1336: {
1337: MatPartitioning mpart;
1338: const char *prefix;
1339: PetscInt i, j, rstart, rend, bs;
1340: PetscBool hasop, isbaij = PETSC_FALSE, foundpart = PETSC_FALSE;
1341: Mat Ad = NULL, adj;
1342: IS ispart, isnumb, *is;
1344: PetscFunctionBegin;
1346: PetscAssertPointer(outis, 3);
1347: PetscCheck(n >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "number of local blocks must be > 0, n = %" PetscInt_FMT, n);
1349: /* Get prefix, row distribution, and block size */
1350: PetscCall(MatGetOptionsPrefix(A, &prefix));
1351: PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
1352: PetscCall(MatGetBlockSize(A, &bs));
1353: PetscCheck(rstart / bs * bs == rstart && rend / bs * bs == rend, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "bad row distribution [%" PetscInt_FMT ",%" PetscInt_FMT ") for matrix block size %" PetscInt_FMT, rstart, rend, bs);
1355: /* Get diagonal block from matrix if possible */
1356: PetscCall(MatHasOperation(A, MATOP_GET_DIAGONAL_BLOCK, &hasop));
1357: if (hasop) PetscCall(MatGetDiagonalBlock(A, &Ad));
1358: if (Ad) {
1359: PetscCall(PetscObjectBaseTypeCompare((PetscObject)Ad, MATSEQBAIJ, &isbaij));
1360: if (!isbaij) PetscCall(PetscObjectBaseTypeCompare((PetscObject)Ad, MATSEQSBAIJ, &isbaij));
1361: }
1362: if (Ad && n > 1) {
1363: PetscBool match, done;
1364: /* Try to setup a good matrix partitioning if available */
1365: PetscCall(MatPartitioningCreate(PETSC_COMM_SELF, &mpart));
1366: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)mpart, prefix));
1367: PetscCall(MatPartitioningSetFromOptions(mpart));
1368: PetscCall(PetscObjectTypeCompare((PetscObject)mpart, MATPARTITIONINGCURRENT, &match));
1369: if (!match) PetscCall(PetscObjectTypeCompare((PetscObject)mpart, MATPARTITIONINGSQUARE, &match));
1370: if (!match) { /* assume a "good" partitioner is available */
1371: PetscInt na;
1372: const PetscInt *ia, *ja;
1373: PetscCall(MatGetRowIJ(Ad, 0, PETSC_TRUE, isbaij, &na, &ia, &ja, &done));
1374: if (done) {
1375: /* Build adjacency matrix by hand. Unfortunately a call to
1376: MatConvert(Ad,MATMPIADJ,MAT_INITIAL_MATRIX,&adj) will
1377: remove the block-aij structure and we cannot expect
1378: MatPartitioning to split vertices as we need */
1379: PetscInt i, j, len, nnz, cnt, *iia = NULL, *jja = NULL;
1380: const PetscInt *row;
1381: nnz = 0;
1382: for (i = 0; i < na; i++) { /* count number of nonzeros */
1383: len = ia[i + 1] - ia[i];
1384: row = ja + ia[i];
1385: for (j = 0; j < len; j++) {
1386: if (row[j] == i) { /* don't count diagonal */
1387: len--;
1388: break;
1389: }
1390: }
1391: nnz += len;
1392: }
1393: PetscCall(PetscMalloc1(na + 1, &iia));
1394: PetscCall(PetscMalloc1(nnz, &jja));
1395: nnz = 0;
1396: iia[0] = 0;
1397: for (i = 0; i < na; i++) { /* fill adjacency */
1398: cnt = 0;
1399: len = ia[i + 1] - ia[i];
1400: row = ja + ia[i];
1401: for (j = 0; j < len; j++) {
1402: if (row[j] != i) { /* if not diagonal */
1403: jja[nnz + cnt++] = row[j];
1404: }
1405: }
1406: nnz += cnt;
1407: iia[i + 1] = nnz;
1408: }
1409: /* Partitioning of the adjacency matrix */
1410: PetscCall(MatCreateMPIAdj(PETSC_COMM_SELF, na, na, iia, jja, NULL, &adj));
1411: PetscCall(MatPartitioningSetAdjacency(mpart, adj));
1412: PetscCall(MatPartitioningSetNParts(mpart, n));
1413: PetscCall(MatPartitioningApply(mpart, &ispart));
1414: PetscCall(ISPartitioningToNumbering(ispart, &isnumb));
1415: PetscCall(MatDestroy(&adj));
1416: foundpart = PETSC_TRUE;
1417: }
1418: PetscCall(MatRestoreRowIJ(Ad, 0, PETSC_TRUE, isbaij, &na, &ia, &ja, &done));
1419: }
1420: PetscCall(MatPartitioningDestroy(&mpart));
1421: }
1423: PetscCall(PetscMalloc1(n, &is));
1424: *outis = is;
1426: if (!foundpart) {
1427: /* Partitioning by contiguous chunks of rows */
1429: PetscInt mbs = (rend - rstart) / bs;
1430: PetscInt start = rstart;
1431: for (i = 0; i < n; i++) {
1432: PetscInt count = (mbs / n + ((mbs % n) > i)) * bs;
1433: PetscCall(ISCreateStride(PETSC_COMM_SELF, count, start, 1, &is[i]));
1434: start += count;
1435: }
1437: } else {
1438: /* Partitioning by adjacency of diagonal block */
1440: const PetscInt *numbering;
1441: PetscInt *count, nidx, *indices, *newidx, start = 0;
1442: /* Get node count in each partition */
1443: PetscCall(PetscMalloc1(n, &count));
1444: PetscCall(ISPartitioningCount(ispart, n, count));
1445: if (isbaij && bs > 1) { /* adjust for the block-aij case */
1446: for (i = 0; i < n; i++) count[i] *= bs;
1447: }
1448: /* Build indices from node numbering */
1449: PetscCall(ISGetLocalSize(isnumb, &nidx));
1450: PetscCall(PetscMalloc1(nidx, &indices));
1451: for (i = 0; i < nidx; i++) indices[i] = i; /* needs to be initialized */
1452: PetscCall(ISGetIndices(isnumb, &numbering));
1453: PetscCall(PetscSortIntWithPermutation(nidx, numbering, indices));
1454: PetscCall(ISRestoreIndices(isnumb, &numbering));
1455: if (isbaij && bs > 1) { /* adjust for the block-aij case */
1456: PetscCall(PetscMalloc1(nidx * bs, &newidx));
1457: for (i = 0; i < nidx; i++) {
1458: for (j = 0; j < bs; j++) newidx[i * bs + j] = indices[i] * bs + j;
1459: }
1460: PetscCall(PetscFree(indices));
1461: nidx *= bs;
1462: indices = newidx;
1463: }
1464: /* Shift to get global indices */
1465: for (i = 0; i < nidx; i++) indices[i] += rstart;
1467: /* Build the index sets for each block */
1468: for (i = 0; i < n; i++) {
1469: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, count[i], &indices[start], PETSC_COPY_VALUES, &is[i]));
1470: PetscCall(ISSort(is[i]));
1471: start += count[i];
1472: }
1474: PetscCall(PetscFree(count));
1475: PetscCall(PetscFree(indices));
1476: PetscCall(ISDestroy(&isnumb));
1477: PetscCall(ISDestroy(&ispart));
1478: }
1479: PetscFunctionReturn(PETSC_SUCCESS);
1480: }
1482: /*@C
1483: PCASMDestroySubdomains - Destroys the index sets created with
1484: `PCASMCreateSubdomains()`. Should be called after setting subdomains with `PCASMSetLocalSubdomains()`.
1486: Collective
1488: Input Parameters:
1489: + n - the number of index sets
1490: . is - the array of index sets
1491: - is_local - the array of local index sets, can be `NULL`
1493: Level: advanced
1495: Developer Note:
1496: The `IS` arguments should be a *[]
1498: .seealso: [](ch_ksp), `PCASM`, `PCASMCreateSubdomains()`, `PCASMSetLocalSubdomains()`
1499: @*/
1500: PetscErrorCode PCASMDestroySubdomains(PetscInt n, IS *is[], IS *is_local[])
1501: {
1502: PetscInt i;
1504: PetscFunctionBegin;
1505: if (n <= 0) PetscFunctionReturn(PETSC_SUCCESS);
1506: if (*is) {
1507: PetscAssertPointer(*is, 2);
1508: for (i = 0; i < n; i++) PetscCall(ISDestroy(&(*is)[i]));
1509: PetscCall(PetscFree(*is));
1510: }
1511: if (is_local && *is_local) {
1512: PetscAssertPointer(*is_local, 3);
1513: for (i = 0; i < n; i++) PetscCall(ISDestroy(&(*is_local)[i]));
1514: PetscCall(PetscFree(*is_local));
1515: }
1516: PetscFunctionReturn(PETSC_SUCCESS);
1517: }
1519: /*@C
1520: PCASMCreateSubdomains2D - Creates the index sets for the overlapping Schwarz
1521: preconditioner, `PCASM`, for a two-dimensional problem on a regular grid.
1523: Not Collective
1525: Input Parameters:
1526: + m - the number of mesh points in the x direction
1527: . n - the number of mesh points in the y direction
1528: . M - the number of subdomains in the x direction
1529: . N - the number of subdomains in the y direction
1530: . dof - degrees of freedom per node
1531: - overlap - overlap in mesh lines
1533: Output Parameters:
1534: + Nsub - the number of subdomains created
1535: . is - array of index sets defining overlapping (if overlap > 0) subdomains
1536: - is_local - array of index sets defining non-overlapping subdomains
1538: Level: advanced
1540: Note:
1541: Presently `PCAMSCreateSubdomains2d()` is valid only for sequential
1542: preconditioners. More general related routines are
1543: `PCASMSetTotalSubdomains()` and `PCASMSetLocalSubdomains()`.
1545: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetLocalSubdomains()`, `PCASMGetSubKSP()`,
1546: `PCASMSetOverlap()`
1547: @*/
1548: PetscErrorCode PCASMCreateSubdomains2D(PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscInt dof, PetscInt overlap, PetscInt *Nsub, IS *is[], IS *is_local[])
1549: {
1550: PetscInt i, j, height, width, ystart, xstart, yleft, yright, xleft, xright, loc_outer;
1551: PetscInt nidx, *idx, loc, ii, jj, count;
1553: PetscFunctionBegin;
1554: PetscCheck(dof == 1, PETSC_COMM_SELF, PETSC_ERR_SUP, "dof must be 1");
1556: *Nsub = N * M;
1557: PetscCall(PetscMalloc1(*Nsub, is));
1558: PetscCall(PetscMalloc1(*Nsub, is_local));
1559: ystart = 0;
1560: loc_outer = 0;
1561: for (i = 0; i < N; i++) {
1562: height = n / N + ((n % N) > i); /* height of subdomain */
1563: PetscCheck(height >= 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many N subdomains for mesh dimension n");
1564: yleft = ystart - overlap;
1565: if (yleft < 0) yleft = 0;
1566: yright = ystart + height + overlap;
1567: if (yright > n) yright = n;
1568: xstart = 0;
1569: for (j = 0; j < M; j++) {
1570: width = m / M + ((m % M) > j); /* width of subdomain */
1571: PetscCheck(width >= 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many M subdomains for mesh dimension m");
1572: xleft = xstart - overlap;
1573: if (xleft < 0) xleft = 0;
1574: xright = xstart + width + overlap;
1575: if (xright > m) xright = m;
1576: nidx = (xright - xleft) * (yright - yleft);
1577: PetscCall(PetscMalloc1(nidx, &idx));
1578: loc = 0;
1579: for (ii = yleft; ii < yright; ii++) {
1580: count = m * ii + xleft;
1581: for (jj = xleft; jj < xright; jj++) idx[loc++] = count++;
1582: }
1583: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, nidx, idx, PETSC_COPY_VALUES, (*is) + loc_outer));
1584: if (overlap == 0) {
1585: PetscCall(PetscObjectReference((PetscObject)(*is)[loc_outer]));
1587: (*is_local)[loc_outer] = (*is)[loc_outer];
1588: } else {
1589: for (loc = 0, ii = ystart; ii < ystart + height; ii++) {
1590: for (jj = xstart; jj < xstart + width; jj++) idx[loc++] = m * ii + jj;
1591: }
1592: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, loc, idx, PETSC_COPY_VALUES, *is_local + loc_outer));
1593: }
1594: PetscCall(PetscFree(idx));
1595: xstart += width;
1596: loc_outer++;
1597: }
1598: ystart += height;
1599: }
1600: for (i = 0; i < *Nsub; i++) PetscCall(ISSort((*is)[i]));
1601: PetscFunctionReturn(PETSC_SUCCESS);
1602: }
1604: /*@C
1605: PCASMGetLocalSubdomains - Gets the local subdomains (for this processor
1606: only) for the additive Schwarz preconditioner, `PCASM`.
1608: Not Collective
1610: Input Parameter:
1611: . pc - the preconditioner context
1613: Output Parameters:
1614: + n - if requested, the number of subdomains for this processor (default value = 1)
1615: . is - if requested, the index sets that define the subdomains for this processor
1616: - is_local - if requested, the index sets that define the local part of the subdomains for this processor (can be `NULL`)
1618: Level: advanced
1620: Note:
1621: The `IS` numbering is in the parallel, global numbering of the vector.
1623: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
1624: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubmatrices()`
1625: @*/
1626: PetscErrorCode PCASMGetLocalSubdomains(PC pc, PetscInt *n, IS *is[], IS *is_local[])
1627: {
1628: PC_ASM *osm = (PC_ASM *)pc->data;
1629: PetscBool match;
1631: PetscFunctionBegin;
1633: if (n) PetscAssertPointer(n, 2);
1634: if (is) PetscAssertPointer(is, 3);
1635: if (is_local) PetscAssertPointer(is_local, 4);
1636: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1637: PetscCheck(match, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "PC is not a PCASM");
1638: if (n) *n = osm->n_local_true;
1639: if (is) *is = osm->is;
1640: if (is_local) *is_local = osm->is_local;
1641: PetscFunctionReturn(PETSC_SUCCESS);
1642: }
1644: /*@C
1645: PCASMGetLocalSubmatrices - Gets the local submatrices (for this processor
1646: only) for the additive Schwarz preconditioner, `PCASM`.
1648: Not Collective
1650: Input Parameter:
1651: . pc - the preconditioner context
1653: Output Parameters:
1654: + n - if requested, the number of matrices for this processor (default value = 1)
1655: - mat - if requested, the matrices
1657: Level: advanced
1659: Notes:
1660: Call after `PCSetUp()` (or `KSPSetUp()`) but before `PCApply()` and before `PCSetUpOnBlocks()`)
1662: Usually one would use `PCSetModifySubMatrices()` to change the submatrices in building the preconditioner.
1664: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
1665: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`, `PCSetModifySubMatrices()`
1666: @*/
1667: PetscErrorCode PCASMGetLocalSubmatrices(PC pc, PetscInt *n, Mat *mat[])
1668: {
1669: PC_ASM *osm;
1670: PetscBool match;
1672: PetscFunctionBegin;
1674: if (n) PetscAssertPointer(n, 2);
1675: if (mat) PetscAssertPointer(mat, 3);
1676: PetscCheck(pc->setupcalled, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONGSTATE, "Must call after KSPSetUp() or PCSetUp().");
1677: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1678: if (!match) {
1679: if (n) *n = 0;
1680: if (mat) *mat = NULL;
1681: } else {
1682: osm = (PC_ASM *)pc->data;
1683: if (n) *n = osm->n_local_true;
1684: if (mat) *mat = osm->pmat;
1685: }
1686: PetscFunctionReturn(PETSC_SUCCESS);
1687: }
1689: /*@
1690: PCASMSetDMSubdomains - Indicates whether to use `DMCreateDomainDecomposition()` to define the subdomains, whenever possible.
1692: Logically Collective
1694: Input Parameters:
1695: + pc - the preconditioner
1696: - flg - boolean indicating whether to use subdomains defined by the `DM`
1698: Options Database Key:
1699: . -pc_asm_dm_subdomains <bool> - use subdomains defined by the `DM` with `DMCreateDomainDecomposition()`
1701: Level: intermediate
1703: Note:
1704: `PCASMSetTotalSubdomains()` and `PCASMSetOverlap()` take precedence over `PCASMSetDMSubdomains()`,
1705: so setting either of the first two effectively turns the latter off.
1707: Developer Note:
1708: This should be `PCASMSetUseDMSubdomains()`, similarly for the options database key
1710: .seealso: [](ch_ksp), `PCASM`, `PCASMGetDMSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`
1711: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`
1712: @*/
1713: PetscErrorCode PCASMSetDMSubdomains(PC pc, PetscBool flg)
1714: {
1715: PC_ASM *osm = (PC_ASM *)pc->data;
1716: PetscBool match;
1718: PetscFunctionBegin;
1721: PetscCheck(!pc->setupcalled, ((PetscObject)pc)->comm, PETSC_ERR_ARG_WRONGSTATE, "Not for a setup PC.");
1722: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1723: if (match) osm->dm_subdomains = flg;
1724: PetscFunctionReturn(PETSC_SUCCESS);
1725: }
1727: /*@
1728: PCASMGetDMSubdomains - Returns flag indicating whether to use `DMCreateDomainDecomposition()` to define the subdomains, whenever possible.
1730: Not Collective
1732: Input Parameter:
1733: . pc - the preconditioner
1735: Output Parameter:
1736: . flg - boolean indicating whether to use subdomains defined by the `DM`
1738: Level: intermediate
1740: Developer Note:
1741: This should be `PCASMSetUseDMSubdomains()`
1743: .seealso: [](ch_ksp), `PCASM`, `PCASMSetDMSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`
1744: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`
1745: @*/
1746: PetscErrorCode PCASMGetDMSubdomains(PC pc, PetscBool *flg)
1747: {
1748: PC_ASM *osm = (PC_ASM *)pc->data;
1749: PetscBool match;
1751: PetscFunctionBegin;
1753: PetscAssertPointer(flg, 2);
1754: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1755: if (match) *flg = osm->dm_subdomains;
1756: else *flg = PETSC_FALSE;
1757: PetscFunctionReturn(PETSC_SUCCESS);
1758: }
1760: /*@
1761: PCASMGetSubMatType - Gets the matrix type used for `PCASM` subsolves, as a string.
1763: Not Collective
1765: Input Parameter:
1766: . pc - the `PC`
1768: Output Parameter:
1769: . sub_mat_type - name of matrix type
1771: Level: advanced
1773: .seealso: [](ch_ksp), `PCASM`, `PCASMSetSubMatType()`, `PCSetType()`, `VecSetType()`, `MatType`, `Mat`
1774: @*/
1775: PetscErrorCode PCASMGetSubMatType(PC pc, MatType *sub_mat_type)
1776: {
1777: PetscFunctionBegin;
1779: PetscTryMethod(pc, "PCASMGetSubMatType_C", (PC, MatType *), (pc, sub_mat_type));
1780: PetscFunctionReturn(PETSC_SUCCESS);
1781: }
1783: /*@
1784: PCASMSetSubMatType - Set the type of matrix used for `PCASM` subsolves
1786: Collective
1788: Input Parameters:
1789: + pc - the `PC` object
1790: - sub_mat_type - the `MatType`
1792: Options Database Key:
1793: . -pc_asm_sub_mat_type <sub_mat_type> - Sets the matrix type used for subsolves, for example, seqaijviennacl.
1794: If you specify a base name like aijviennacl, the corresponding sequential type is assumed.
1796: Note:
1797: See `MatType` for available types
1799: Level: advanced
1801: .seealso: [](ch_ksp), `PCASM`, `PCASMGetSubMatType()`, `PCSetType()`, `VecSetType()`, `MatType`, `Mat`
1802: @*/
1803: PetscErrorCode PCASMSetSubMatType(PC pc, MatType sub_mat_type)
1804: {
1805: PetscFunctionBegin;
1807: PetscTryMethod(pc, "PCASMSetSubMatType_C", (PC, MatType), (pc, sub_mat_type));
1808: PetscFunctionReturn(PETSC_SUCCESS);
1809: }