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(viewer));
47: PetscCall(KSPView(osm->ksp[0], sviewer));
48: PetscCall(PetscViewerASCIIPopTab(viewer));
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", (int)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(PetscViewerASCIISynchronizedPrintf(sviewer, "[%d] local block number %" PetscInt_FMT ", size = %" PetscInt_FMT "\n", (int)rank, i, bsz));
63: PetscCall(KSPView(osm->ksp[i], sviewer));
64: PetscCall(PetscViewerASCIISynchronizedPrintf(sviewer, "- - - - - - - - - - - - - - - - - -\n"));
65: }
66: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
67: PetscCall(PetscViewerASCIIPopTab(viewer));
68: PetscCall(PetscViewerFlush(viewer));
69: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
70: }
71: } else if (isstring) {
72: PetscCall(PetscViewerStringSPrintf(viewer, " blocks=%" PetscInt_FMT ", overlap=%" PetscInt_FMT ", type=%s", osm->n, osm->overlap, PCASMTypes[osm->type]));
73: PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
74: if (osm->ksp) PetscCall(KSPView(osm->ksp[0], sviewer));
75: PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
76: }
77: PetscFunctionReturn(PETSC_SUCCESS);
78: }
80: static PetscErrorCode PCASMPrintSubdomains(PC pc)
81: {
82: PC_ASM *osm = (PC_ASM *)pc->data;
83: const char *prefix;
84: char fname[PETSC_MAX_PATH_LEN + 1];
85: PetscViewer viewer, sviewer;
86: char *s;
87: PetscInt i, j, nidx;
88: const PetscInt *idx;
89: PetscMPIInt rank, size;
91: PetscFunctionBegin;
92: PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size));
93: PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank));
94: PetscCall(PCGetOptionsPrefix(pc, &prefix));
95: PetscCall(PetscOptionsGetString(NULL, prefix, "-pc_asm_print_subdomains", fname, sizeof(fname), NULL));
96: if (fname[0] == 0) PetscCall(PetscStrncpy(fname, "stdout", sizeof(fname)));
97: PetscCall(PetscViewerASCIIOpen(PetscObjectComm((PetscObject)pc), fname, &viewer));
98: for (i = 0; i < osm->n_local; i++) {
99: if (i < osm->n_local_true) {
100: PetscCall(ISGetLocalSize(osm->is[i], &nidx));
101: PetscCall(ISGetIndices(osm->is[i], &idx));
102: /* Print to a string viewer; no more than 15 characters per index plus 512 char for the header.*/
103: #define len 16 * (nidx + 1) + 512
104: PetscCall(PetscMalloc1(len, &s));
105: PetscCall(PetscViewerStringOpen(PETSC_COMM_SELF, s, len, &sviewer));
106: #undef len
107: PetscCall(PetscViewerStringSPrintf(sviewer, "[%d:%d] Subdomain %" PetscInt_FMT " with overlap:\n", rank, size, i));
108: for (j = 0; j < nidx; j++) PetscCall(PetscViewerStringSPrintf(sviewer, "%" PetscInt_FMT " ", idx[j]));
109: PetscCall(ISRestoreIndices(osm->is[i], &idx));
110: PetscCall(PetscViewerStringSPrintf(sviewer, "\n"));
111: PetscCall(PetscViewerDestroy(&sviewer));
112: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
113: PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%s", s));
114: PetscCall(PetscViewerFlush(viewer));
115: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
116: PetscCall(PetscFree(s));
117: if (osm->is_local) {
118: /* Print to a string viewer; no more than 15 characters per index plus 512 char for the header.*/
119: #define len 16 * (nidx + 1) + 512
120: PetscCall(PetscMalloc1(len, &s));
121: PetscCall(PetscViewerStringOpen(PETSC_COMM_SELF, s, len, &sviewer));
122: #undef len
123: PetscCall(PetscViewerStringSPrintf(sviewer, "[%d:%d] Subdomain %" PetscInt_FMT " without overlap:\n", rank, size, i));
124: PetscCall(ISGetLocalSize(osm->is_local[i], &nidx));
125: PetscCall(ISGetIndices(osm->is_local[i], &idx));
126: for (j = 0; j < nidx; j++) PetscCall(PetscViewerStringSPrintf(sviewer, "%" PetscInt_FMT " ", idx[j]));
127: PetscCall(ISRestoreIndices(osm->is_local[i], &idx));
128: PetscCall(PetscViewerStringSPrintf(sviewer, "\n"));
129: PetscCall(PetscViewerDestroy(&sviewer));
130: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
131: PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%s", s));
132: PetscCall(PetscViewerFlush(viewer));
133: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
134: PetscCall(PetscFree(s));
135: }
136: } else {
137: /* Participate in collective viewer calls. */
138: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
139: PetscCall(PetscViewerFlush(viewer));
140: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
141: /* Assume either all ranks have is_local or none do. */
142: if (osm->is_local) {
143: PetscCall(PetscViewerASCIIPushSynchronized(viewer));
144: PetscCall(PetscViewerFlush(viewer));
145: PetscCall(PetscViewerASCIIPopSynchronized(viewer));
146: }
147: }
148: }
149: PetscCall(PetscViewerFlush(viewer));
150: PetscCall(PetscViewerDestroy(&viewer));
151: PetscFunctionReturn(PETSC_SUCCESS);
152: }
154: static PetscErrorCode PCSetUp_ASM(PC pc)
155: {
156: PC_ASM *osm = (PC_ASM *)pc->data;
157: PetscBool flg;
158: PetscInt i, m, m_local;
159: MatReuse scall = MAT_REUSE_MATRIX;
160: IS isl;
161: KSP ksp;
162: PC subpc;
163: const char *prefix, *pprefix;
164: Vec vec;
165: DM *domain_dm = 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: PetscCall(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(MatDestroyMatrices(osm->n_local_true, &osm->pmat));
281: scall = MAT_INITIAL_MATRIX;
282: }
283: }
285: /* Destroy previous submatrices of a different type than pc->pmat since MAT_REUSE_MATRIX won't work in that case */
286: if (scall == MAT_REUSE_MATRIX && osm->sub_mat_type) {
287: if (osm->n_local_true > 0) PetscCall(MatDestroySubMatrices(osm->n_local_true, &osm->pmat));
288: scall = MAT_INITIAL_MATRIX;
289: }
291: /*
292: Extract out the submatrices
293: */
294: PetscCall(MatCreateSubMatrices(pc->pmat, osm->n_local_true, osm->is, osm->is, scall, &osm->pmat));
295: if (scall == MAT_INITIAL_MATRIX) {
296: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)pc->pmat, &pprefix));
297: for (i = 0; i < osm->n_local_true; i++) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)osm->pmat[i], pprefix));
298: }
300: /* Convert the types of the submatrices (if needbe) */
301: if (osm->sub_mat_type) {
302: for (i = 0; i < osm->n_local_true; i++) PetscCall(MatConvert(osm->pmat[i], osm->sub_mat_type, MAT_INPLACE_MATRIX, &(osm->pmat[i])));
303: }
305: if (!pc->setupcalled) {
306: VecType vtype;
308: /* Create the local work vectors (from the local matrices) and scatter contexts */
309: PetscCall(MatCreateVecs(pc->pmat, &vec, NULL));
311: 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");
312: if (osm->is_local && osm->type != PC_ASM_BASIC && osm->loctype == PC_COMPOSITE_ADDITIVE) PetscCall(PetscMalloc1(osm->n_local_true, &osm->lprolongation));
313: PetscCall(PetscMalloc1(osm->n_local_true, &osm->lrestriction));
314: PetscCall(PetscMalloc1(osm->n_local_true, &osm->x));
315: PetscCall(PetscMalloc1(osm->n_local_true, &osm->y));
317: PetscCall(ISGetLocalSize(osm->lis, &m));
318: PetscCall(ISCreateStride(PETSC_COMM_SELF, m, 0, 1, &isl));
319: PetscCall(MatGetVecType(osm->pmat[0], &vtype));
320: PetscCall(VecCreate(PETSC_COMM_SELF, &osm->lx));
321: PetscCall(VecSetSizes(osm->lx, m, m));
322: PetscCall(VecSetType(osm->lx, vtype));
323: PetscCall(VecDuplicate(osm->lx, &osm->ly));
324: PetscCall(VecScatterCreate(vec, osm->lis, osm->lx, isl, &osm->restriction));
325: PetscCall(ISDestroy(&isl));
327: for (i = 0; i < osm->n_local_true; ++i) {
328: ISLocalToGlobalMapping ltog;
329: IS isll;
330: const PetscInt *idx_is;
331: PetscInt *idx_lis, nout;
333: PetscCall(ISGetLocalSize(osm->is[i], &m));
334: PetscCall(MatCreateVecs(osm->pmat[i], &osm->x[i], NULL));
335: PetscCall(VecDuplicate(osm->x[i], &osm->y[i]));
337: /* generate a scatter from ly to y[i] picking all the overlapping is[i] entries */
338: PetscCall(ISLocalToGlobalMappingCreateIS(osm->lis, <og));
339: PetscCall(ISGetLocalSize(osm->is[i], &m));
340: PetscCall(ISGetIndices(osm->is[i], &idx_is));
341: PetscCall(PetscMalloc1(m, &idx_lis));
342: PetscCall(ISGlobalToLocalMappingApply(ltog, IS_GTOLM_DROP, m, idx_is, &nout, idx_lis));
343: PetscCheck(nout == m, PETSC_COMM_SELF, PETSC_ERR_PLIB, "is not a subset of lis");
344: PetscCall(ISRestoreIndices(osm->is[i], &idx_is));
345: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m, idx_lis, PETSC_OWN_POINTER, &isll));
346: PetscCall(ISLocalToGlobalMappingDestroy(<og));
347: PetscCall(ISCreateStride(PETSC_COMM_SELF, m, 0, 1, &isl));
348: PetscCall(VecScatterCreate(osm->ly, isll, osm->y[i], isl, &osm->lrestriction[i]));
349: PetscCall(ISDestroy(&isll));
350: PetscCall(ISDestroy(&isl));
351: if (osm->lprolongation) { /* generate a scatter from y[i] to ly picking only the the non-overlapping is_local[i] entries */
352: ISLocalToGlobalMapping ltog;
353: IS isll, isll_local;
354: const PetscInt *idx_local;
355: PetscInt *idx1, *idx2, nout;
357: PetscCall(ISGetLocalSize(osm->is_local[i], &m_local));
358: PetscCall(ISGetIndices(osm->is_local[i], &idx_local));
360: PetscCall(ISLocalToGlobalMappingCreateIS(osm->is[i], <og));
361: PetscCall(PetscMalloc1(m_local, &idx1));
362: PetscCall(ISGlobalToLocalMappingApply(ltog, IS_GTOLM_DROP, m_local, idx_local, &nout, idx1));
363: PetscCall(ISLocalToGlobalMappingDestroy(<og));
364: PetscCheck(nout == m_local, PETSC_COMM_SELF, PETSC_ERR_PLIB, "is_local not a subset of is");
365: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m_local, idx1, PETSC_OWN_POINTER, &isll));
367: PetscCall(ISLocalToGlobalMappingCreateIS(osm->lis, <og));
368: PetscCall(PetscMalloc1(m_local, &idx2));
369: PetscCall(ISGlobalToLocalMappingApply(ltog, IS_GTOLM_DROP, m_local, idx_local, &nout, idx2));
370: PetscCall(ISLocalToGlobalMappingDestroy(<og));
371: PetscCheck(nout == m_local, PETSC_COMM_SELF, PETSC_ERR_PLIB, "is_local not a subset of lis");
372: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m_local, idx2, PETSC_OWN_POINTER, &isll_local));
374: PetscCall(ISRestoreIndices(osm->is_local[i], &idx_local));
375: PetscCall(VecScatterCreate(osm->y[i], isll, osm->ly, isll_local, &osm->lprolongation[i]));
377: PetscCall(ISDestroy(&isll));
378: PetscCall(ISDestroy(&isll_local));
379: }
380: }
381: PetscCall(VecDestroy(&vec));
382: }
384: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) {
385: IS *cis;
386: PetscInt c;
388: PetscCall(PetscMalloc1(osm->n_local_true, &cis));
389: for (c = 0; c < osm->n_local_true; ++c) cis[c] = osm->lis;
390: PetscCall(MatCreateSubMatrices(pc->pmat, osm->n_local_true, osm->is, cis, scall, &osm->lmats));
391: PetscCall(PetscFree(cis));
392: }
394: /* Return control to the user so that the submatrices can be modified (e.g., to apply
395: different boundary conditions for the submatrices than for the global problem) */
396: PetscCall(PCModifySubMatrices(pc, osm->n_local_true, osm->is, osm->is, osm->pmat, pc->modifysubmatricesP));
398: /*
399: Loop over subdomains putting them into local ksp
400: */
401: PetscCall(KSPGetOptionsPrefix(osm->ksp[0], &prefix));
402: for (i = 0; i < osm->n_local_true; i++) {
403: PetscCall(KSPSetOperators(osm->ksp[i], osm->pmat[i], osm->pmat[i]));
404: PetscCall(MatSetOptionsPrefix(osm->pmat[i], prefix));
405: if (!pc->setupcalled) PetscCall(KSPSetFromOptions(osm->ksp[i]));
406: }
407: PetscFunctionReturn(PETSC_SUCCESS);
408: }
410: static PetscErrorCode PCSetUpOnBlocks_ASM(PC pc)
411: {
412: PC_ASM *osm = (PC_ASM *)pc->data;
413: PetscInt i;
414: KSPConvergedReason reason;
416: PetscFunctionBegin;
417: for (i = 0; i < osm->n_local_true; i++) {
418: PetscCall(KSPSetUp(osm->ksp[i]));
419: PetscCall(KSPGetConvergedReason(osm->ksp[i], &reason));
420: if (reason == KSP_DIVERGED_PC_FAILED) pc->failedreason = PC_SUBPC_ERROR;
421: }
422: PetscFunctionReturn(PETSC_SUCCESS);
423: }
425: static PetscErrorCode PCApply_ASM(PC pc, Vec x, Vec y)
426: {
427: PC_ASM *osm = (PC_ASM *)pc->data;
428: PetscInt i, n_local_true = osm->n_local_true;
429: ScatterMode forward = SCATTER_FORWARD, reverse = SCATTER_REVERSE;
431: PetscFunctionBegin;
432: /*
433: support for limiting the restriction or interpolation to only local
434: subdomain values (leaving the other values 0).
435: */
436: if (!(osm->type & PC_ASM_RESTRICT)) {
437: forward = SCATTER_FORWARD_LOCAL;
438: /* have to zero the work RHS since scatter may leave some slots empty */
439: PetscCall(VecSet(osm->lx, 0.0));
440: }
441: if (!(osm->type & PC_ASM_INTERPOLATE)) reverse = SCATTER_REVERSE_LOCAL;
443: 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]);
444: /* zero the global and the local solutions */
445: PetscCall(VecSet(y, 0.0));
446: PetscCall(VecSet(osm->ly, 0.0));
448: /* copy the global RHS to local RHS including the ghost nodes */
449: PetscCall(VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
450: PetscCall(VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
452: /* restrict local RHS to the overlapping 0-block RHS */
453: PetscCall(VecScatterBegin(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
454: PetscCall(VecScatterEnd(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
456: /* do the local solves */
457: for (i = 0; i < n_local_true; ++i) {
458: /* solve the overlapping i-block */
459: PetscCall(PetscLogEventBegin(PC_ApplyOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
460: PetscCall(KSPSolve(osm->ksp[i], osm->x[i], osm->y[i]));
461: PetscCall(KSPCheckSolve(osm->ksp[i], pc, osm->y[i]));
462: PetscCall(PetscLogEventEnd(PC_ApplyOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
464: if (osm->lprolongation && osm->type != PC_ASM_INTERPOLATE) { /* interpolate the non-overlapping i-block solution to the local solution (only for restrictive additive) */
465: PetscCall(VecScatterBegin(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
466: PetscCall(VecScatterEnd(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
467: } else { /* interpolate the overlapping i-block solution to the local solution */
468: PetscCall(VecScatterBegin(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
469: PetscCall(VecScatterEnd(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
470: }
472: if (i < n_local_true - 1) {
473: /* restrict local RHS to the overlapping (i+1)-block RHS */
474: PetscCall(VecScatterBegin(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
475: PetscCall(VecScatterEnd(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
477: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) {
478: /* update the overlapping (i+1)-block RHS using the current local solution */
479: PetscCall(MatMult(osm->lmats[i + 1], osm->ly, osm->y[i + 1]));
480: PetscCall(VecAXPBY(osm->x[i + 1], -1., 1., osm->y[i + 1]));
481: }
482: }
483: }
484: /* add the local solution to the global solution including the ghost nodes */
485: PetscCall(VecScatterBegin(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
486: PetscCall(VecScatterEnd(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
487: PetscFunctionReturn(PETSC_SUCCESS);
488: }
490: static PetscErrorCode PCMatApply_ASM(PC pc, Mat X, Mat Y)
491: {
492: PC_ASM *osm = (PC_ASM *)pc->data;
493: Mat Z, W;
494: Vec x;
495: PetscInt i, m, N;
496: ScatterMode forward = SCATTER_FORWARD, reverse = SCATTER_REVERSE;
498: PetscFunctionBegin;
499: PetscCheck(osm->n_local_true <= 1, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Not yet implemented");
500: /*
501: support for limiting the restriction or interpolation to only local
502: subdomain values (leaving the other values 0).
503: */
504: if (!(osm->type & PC_ASM_RESTRICT)) {
505: forward = SCATTER_FORWARD_LOCAL;
506: /* have to zero the work RHS since scatter may leave some slots empty */
507: PetscCall(VecSet(osm->lx, 0.0));
508: }
509: if (!(osm->type & PC_ASM_INTERPOLATE)) reverse = SCATTER_REVERSE_LOCAL;
510: PetscCall(VecGetLocalSize(osm->x[0], &m));
511: PetscCall(MatGetSize(X, NULL, &N));
512: PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, m, N, NULL, &Z));
514: 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]);
515: /* zero the global and the local solutions */
516: PetscCall(MatZeroEntries(Y));
517: PetscCall(VecSet(osm->ly, 0.0));
519: for (i = 0; i < N; ++i) {
520: PetscCall(MatDenseGetColumnVecRead(X, i, &x));
521: /* copy the global RHS to local RHS including the ghost nodes */
522: PetscCall(VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
523: PetscCall(VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
524: PetscCall(MatDenseRestoreColumnVecRead(X, i, &x));
526: PetscCall(MatDenseGetColumnVecWrite(Z, i, &x));
527: /* restrict local RHS to the overlapping 0-block RHS */
528: PetscCall(VecScatterBegin(osm->lrestriction[0], osm->lx, x, INSERT_VALUES, forward));
529: PetscCall(VecScatterEnd(osm->lrestriction[0], osm->lx, x, INSERT_VALUES, forward));
530: PetscCall(MatDenseRestoreColumnVecWrite(Z, i, &x));
531: }
532: PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, m, N, NULL, &W));
533: /* solve the overlapping 0-block */
534: PetscCall(PetscLogEventBegin(PC_ApplyOnBlocks, osm->ksp[0], Z, W, 0));
535: PetscCall(KSPMatSolve(osm->ksp[0], Z, W));
536: PetscCall(KSPCheckSolve(osm->ksp[0], pc, NULL));
537: PetscCall(PetscLogEventEnd(PC_ApplyOnBlocks, osm->ksp[0], Z, W, 0));
538: PetscCall(MatDestroy(&Z));
540: for (i = 0; i < N; ++i) {
541: PetscCall(VecSet(osm->ly, 0.0));
542: PetscCall(MatDenseGetColumnVecRead(W, i, &x));
543: if (osm->lprolongation && osm->type != PC_ASM_INTERPOLATE) { /* interpolate the non-overlapping 0-block solution to the local solution (only for restrictive additive) */
544: PetscCall(VecScatterBegin(osm->lprolongation[0], x, osm->ly, ADD_VALUES, forward));
545: PetscCall(VecScatterEnd(osm->lprolongation[0], x, osm->ly, ADD_VALUES, forward));
546: } else { /* interpolate the overlapping 0-block solution to the local solution */
547: PetscCall(VecScatterBegin(osm->lrestriction[0], x, osm->ly, ADD_VALUES, reverse));
548: PetscCall(VecScatterEnd(osm->lrestriction[0], x, osm->ly, ADD_VALUES, reverse));
549: }
550: PetscCall(MatDenseRestoreColumnVecRead(W, i, &x));
552: PetscCall(MatDenseGetColumnVecWrite(Y, i, &x));
553: /* add the local solution to the global solution including the ghost nodes */
554: PetscCall(VecScatterBegin(osm->restriction, osm->ly, x, ADD_VALUES, reverse));
555: PetscCall(VecScatterEnd(osm->restriction, osm->ly, x, ADD_VALUES, reverse));
556: PetscCall(MatDenseRestoreColumnVecWrite(Y, i, &x));
557: }
558: PetscCall(MatDestroy(&W));
559: PetscFunctionReturn(PETSC_SUCCESS);
560: }
562: static PetscErrorCode PCApplyTranspose_ASM(PC pc, Vec x, Vec y)
563: {
564: PC_ASM *osm = (PC_ASM *)pc->data;
565: PetscInt i, n_local_true = osm->n_local_true;
566: ScatterMode forward = SCATTER_FORWARD, reverse = SCATTER_REVERSE;
568: PetscFunctionBegin;
569: /*
570: Support for limiting the restriction or interpolation to only local
571: subdomain values (leaving the other values 0).
573: Note: these are reversed from the PCApply_ASM() because we are applying the
574: transpose of the three terms
575: */
577: if (!(osm->type & PC_ASM_INTERPOLATE)) {
578: forward = SCATTER_FORWARD_LOCAL;
579: /* have to zero the work RHS since scatter may leave some slots empty */
580: PetscCall(VecSet(osm->lx, 0.0));
581: }
582: if (!(osm->type & PC_ASM_RESTRICT)) reverse = SCATTER_REVERSE_LOCAL;
584: /* zero the global and the local solutions */
585: PetscCall(VecSet(y, 0.0));
586: PetscCall(VecSet(osm->ly, 0.0));
588: /* Copy the global RHS to local RHS including the ghost nodes */
589: PetscCall(VecScatterBegin(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
590: PetscCall(VecScatterEnd(osm->restriction, x, osm->lx, INSERT_VALUES, forward));
592: /* Restrict local RHS to the overlapping 0-block RHS */
593: PetscCall(VecScatterBegin(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
594: PetscCall(VecScatterEnd(osm->lrestriction[0], osm->lx, osm->x[0], INSERT_VALUES, forward));
596: /* do the local solves */
597: for (i = 0; i < n_local_true; ++i) {
598: /* solve the overlapping i-block */
599: PetscCall(PetscLogEventBegin(PC_ApplyOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
600: PetscCall(KSPSolveTranspose(osm->ksp[i], osm->x[i], osm->y[i]));
601: PetscCall(KSPCheckSolve(osm->ksp[i], pc, osm->y[i]));
602: PetscCall(PetscLogEventEnd(PC_ApplyOnBlocks, osm->ksp[i], osm->x[i], osm->y[i], 0));
604: if (osm->lprolongation && osm->type != PC_ASM_RESTRICT) { /* interpolate the non-overlapping i-block solution to the local solution */
605: PetscCall(VecScatterBegin(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
606: PetscCall(VecScatterEnd(osm->lprolongation[i], osm->y[i], osm->ly, ADD_VALUES, forward));
607: } else { /* interpolate the overlapping i-block solution to the local solution */
608: PetscCall(VecScatterBegin(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
609: PetscCall(VecScatterEnd(osm->lrestriction[i], osm->y[i], osm->ly, ADD_VALUES, reverse));
610: }
612: if (i < n_local_true - 1) {
613: /* Restrict local RHS to the overlapping (i+1)-block RHS */
614: PetscCall(VecScatterBegin(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
615: PetscCall(VecScatterEnd(osm->lrestriction[i + 1], osm->lx, osm->x[i + 1], INSERT_VALUES, forward));
616: }
617: }
618: /* Add the local solution to the global solution including the ghost nodes */
619: PetscCall(VecScatterBegin(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
620: PetscCall(VecScatterEnd(osm->restriction, osm->ly, y, ADD_VALUES, reverse));
621: PetscFunctionReturn(PETSC_SUCCESS);
622: }
624: static PetscErrorCode PCReset_ASM(PC pc)
625: {
626: PC_ASM *osm = (PC_ASM *)pc->data;
627: PetscInt i;
629: PetscFunctionBegin;
630: if (osm->ksp) {
631: for (i = 0; i < osm->n_local_true; i++) PetscCall(KSPReset(osm->ksp[i]));
632: }
633: if (osm->pmat) {
634: if (osm->n_local_true > 0) PetscCall(MatDestroySubMatrices(osm->n_local_true, &osm->pmat));
635: }
636: if (osm->lrestriction) {
637: PetscCall(VecScatterDestroy(&osm->restriction));
638: for (i = 0; i < osm->n_local_true; i++) {
639: PetscCall(VecScatterDestroy(&osm->lrestriction[i]));
640: if (osm->lprolongation) PetscCall(VecScatterDestroy(&osm->lprolongation[i]));
641: PetscCall(VecDestroy(&osm->x[i]));
642: PetscCall(VecDestroy(&osm->y[i]));
643: }
644: PetscCall(PetscFree(osm->lrestriction));
645: if (osm->lprolongation) PetscCall(PetscFree(osm->lprolongation));
646: PetscCall(PetscFree(osm->x));
647: PetscCall(PetscFree(osm->y));
648: }
649: PetscCall(PCASMDestroySubdomains(osm->n_local_true, osm->is, osm->is_local));
650: PetscCall(ISDestroy(&osm->lis));
651: PetscCall(VecDestroy(&osm->lx));
652: PetscCall(VecDestroy(&osm->ly));
653: if (osm->loctype == PC_COMPOSITE_MULTIPLICATIVE) PetscCall(MatDestroyMatrices(osm->n_local_true, &osm->lmats));
655: PetscCall(PetscFree(osm->sub_mat_type));
657: osm->is = NULL;
658: osm->is_local = NULL;
659: PetscFunctionReturn(PETSC_SUCCESS);
660: }
662: static PetscErrorCode PCDestroy_ASM(PC pc)
663: {
664: PC_ASM *osm = (PC_ASM *)pc->data;
665: PetscInt i;
667: PetscFunctionBegin;
668: PetscCall(PCReset_ASM(pc));
669: if (osm->ksp) {
670: for (i = 0; i < osm->n_local_true; i++) PetscCall(KSPDestroy(&osm->ksp[i]));
671: PetscCall(PetscFree(osm->ksp));
672: }
673: PetscCall(PetscFree(pc->data));
675: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalSubdomains_C", NULL));
676: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetTotalSubdomains_C", NULL));
677: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetOverlap_C", NULL));
678: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetType_C", NULL));
679: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetType_C", NULL));
680: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalType_C", NULL));
681: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetLocalType_C", NULL));
682: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSortIndices_C", NULL));
683: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubKSP_C", NULL));
684: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubMatType_C", NULL));
685: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSubMatType_C", NULL));
686: PetscFunctionReturn(PETSC_SUCCESS);
687: }
689: static PetscErrorCode PCSetFromOptions_ASM(PC pc, PetscOptionItems *PetscOptionsObject)
690: {
691: PC_ASM *osm = (PC_ASM *)pc->data;
692: PetscInt blocks, ovl;
693: PetscBool flg;
694: PCASMType asmtype;
695: PCCompositeType loctype;
696: char sub_mat_type[256];
698: PetscFunctionBegin;
699: PetscOptionsHeadBegin(PetscOptionsObject, "Additive Schwarz options");
700: PetscCall(PetscOptionsBool("-pc_asm_dm_subdomains", "Use DMCreateDomainDecomposition() to define subdomains", "PCASMSetDMSubdomains", osm->dm_subdomains, &osm->dm_subdomains, &flg));
701: PetscCall(PetscOptionsInt("-pc_asm_blocks", "Number of subdomains", "PCASMSetTotalSubdomains", osm->n, &blocks, &flg));
702: if (flg) {
703: PetscCall(PCASMSetTotalSubdomains(pc, blocks, NULL, NULL));
704: osm->dm_subdomains = PETSC_FALSE;
705: }
706: PetscCall(PetscOptionsInt("-pc_asm_local_blocks", "Number of local subdomains", "PCASMSetLocalSubdomains", osm->n_local_true, &blocks, &flg));
707: if (flg) {
708: PetscCall(PCASMSetLocalSubdomains(pc, blocks, NULL, NULL));
709: osm->dm_subdomains = PETSC_FALSE;
710: }
711: PetscCall(PetscOptionsInt("-pc_asm_overlap", "Number of grid points overlap", "PCASMSetOverlap", osm->overlap, &ovl, &flg));
712: if (flg) {
713: PetscCall(PCASMSetOverlap(pc, ovl));
714: osm->dm_subdomains = PETSC_FALSE;
715: }
716: flg = PETSC_FALSE;
717: PetscCall(PetscOptionsEnum("-pc_asm_type", "Type of restriction/extension", "PCASMSetType", PCASMTypes, (PetscEnum)osm->type, (PetscEnum *)&asmtype, &flg));
718: if (flg) PetscCall(PCASMSetType(pc, asmtype));
719: flg = PETSC_FALSE;
720: PetscCall(PetscOptionsEnum("-pc_asm_local_type", "Type of local solver composition", "PCASMSetLocalType", PCCompositeTypes, (PetscEnum)osm->loctype, (PetscEnum *)&loctype, &flg));
721: if (flg) PetscCall(PCASMSetLocalType(pc, loctype));
722: PetscCall(PetscOptionsFList("-pc_asm_sub_mat_type", "Subsolve Matrix Type", "PCASMSetSubMatType", MatList, NULL, sub_mat_type, 256, &flg));
723: if (flg) PetscCall(PCASMSetSubMatType(pc, sub_mat_type));
724: PetscOptionsHeadEnd();
725: PetscFunctionReturn(PETSC_SUCCESS);
726: }
728: static PetscErrorCode PCASMSetLocalSubdomains_ASM(PC pc, PetscInt n, IS is[], IS is_local[])
729: {
730: PC_ASM *osm = (PC_ASM *)pc->data;
731: PetscInt i;
733: PetscFunctionBegin;
734: PetscCheck(n >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Each process must have 1 or more blocks, n = %" PetscInt_FMT, n);
735: PetscCheck(!pc->setupcalled || (n == osm->n_local_true && !is), PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONGSTATE, "PCASMSetLocalSubdomains() should be called before calling PCSetUp().");
737: if (!pc->setupcalled) {
738: if (is) {
739: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)is[i]));
740: }
741: if (is_local) {
742: for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)is_local[i]));
743: }
744: PetscCall(PCASMDestroySubdomains(osm->n_local_true, osm->is, osm->is_local));
746: if (osm->ksp && osm->n_local_true != n) {
747: for (i = 0; i < osm->n_local_true; i++) PetscCall(KSPDestroy(&osm->ksp[i]));
748: PetscCall(PetscFree(osm->ksp));
749: }
751: osm->n_local_true = n;
752: osm->is = NULL;
753: osm->is_local = NULL;
754: if (is) {
755: PetscCall(PetscMalloc1(n, &osm->is));
756: for (i = 0; i < n; i++) osm->is[i] = is[i];
757: /* Flag indicating that the user has set overlapping subdomains so PCASM should not increase their size. */
758: osm->overlap = -1;
759: }
760: if (is_local) {
761: PetscCall(PetscMalloc1(n, &osm->is_local));
762: for (i = 0; i < n; i++) osm->is_local[i] = is_local[i];
763: if (!is) {
764: PetscCall(PetscMalloc1(osm->n_local_true, &osm->is));
765: for (i = 0; i < osm->n_local_true; i++) {
766: if (osm->overlap > 0) { /* With positive overlap, osm->is[i] will be modified */
767: PetscCall(ISDuplicate(osm->is_local[i], &osm->is[i]));
768: PetscCall(ISCopy(osm->is_local[i], osm->is[i]));
769: } else {
770: PetscCall(PetscObjectReference((PetscObject)osm->is_local[i]));
771: osm->is[i] = osm->is_local[i];
772: }
773: }
774: }
775: }
776: }
777: PetscFunctionReturn(PETSC_SUCCESS);
778: }
780: static PetscErrorCode PCASMSetTotalSubdomains_ASM(PC pc, PetscInt N, IS *is, IS *is_local)
781: {
782: PC_ASM *osm = (PC_ASM *)pc->data;
783: PetscMPIInt rank, size;
784: PetscInt n;
786: PetscFunctionBegin;
787: PetscCheck(N >= 1, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_OUTOFRANGE, "Number of total blocks must be > 0, N = %" PetscInt_FMT, N);
788: PetscCheck(!is && !is_local, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Use PCASMSetLocalSubdomains() to set specific index sets\n\they cannot be set globally yet.");
790: /*
791: Split the subdomains equally among all processors
792: */
793: PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank));
794: PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size));
795: n = N / size + ((N % size) > rank);
796: PetscCheck(n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Process %d must have at least one block: total processors %d total blocks %" PetscInt_FMT, (int)rank, (int)size, N);
797: PetscCheck(!pc->setupcalled || n == osm->n_local_true, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "PCASMSetTotalSubdomains() should be called before PCSetUp().");
798: if (!pc->setupcalled) {
799: PetscCall(PCASMDestroySubdomains(osm->n_local_true, osm->is, osm->is_local));
801: osm->n_local_true = n;
802: osm->is = NULL;
803: osm->is_local = NULL;
804: }
805: PetscFunctionReturn(PETSC_SUCCESS);
806: }
808: static PetscErrorCode PCASMSetOverlap_ASM(PC pc, PetscInt ovl)
809: {
810: PC_ASM *osm = (PC_ASM *)pc->data;
812: PetscFunctionBegin;
813: PetscCheck(ovl >= 0, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_OUTOFRANGE, "Negative overlap value requested");
814: PetscCheck(!pc->setupcalled || ovl == osm->overlap, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONGSTATE, "PCASMSetOverlap() should be called before PCSetUp().");
815: if (!pc->setupcalled) osm->overlap = ovl;
816: PetscFunctionReturn(PETSC_SUCCESS);
817: }
819: static PetscErrorCode PCASMSetType_ASM(PC pc, PCASMType type)
820: {
821: PC_ASM *osm = (PC_ASM *)pc->data;
823: PetscFunctionBegin;
824: osm->type = type;
825: osm->type_set = PETSC_TRUE;
826: PetscFunctionReturn(PETSC_SUCCESS);
827: }
829: static PetscErrorCode PCASMGetType_ASM(PC pc, PCASMType *type)
830: {
831: PC_ASM *osm = (PC_ASM *)pc->data;
833: PetscFunctionBegin;
834: *type = osm->type;
835: PetscFunctionReturn(PETSC_SUCCESS);
836: }
838: static PetscErrorCode PCASMSetLocalType_ASM(PC pc, PCCompositeType type)
839: {
840: PC_ASM *osm = (PC_ASM *)pc->data;
842: PetscFunctionBegin;
843: PetscCheck(type == PC_COMPOSITE_ADDITIVE || type == PC_COMPOSITE_MULTIPLICATIVE, PetscObjectComm((PetscObject)pc), PETSC_ERR_SUP, "Only supports additive or multiplicative as the local type");
844: osm->loctype = type;
845: PetscFunctionReturn(PETSC_SUCCESS);
846: }
848: static PetscErrorCode PCASMGetLocalType_ASM(PC pc, PCCompositeType *type)
849: {
850: PC_ASM *osm = (PC_ASM *)pc->data;
852: PetscFunctionBegin;
853: *type = osm->loctype;
854: PetscFunctionReturn(PETSC_SUCCESS);
855: }
857: static PetscErrorCode PCASMSetSortIndices_ASM(PC pc, PetscBool doSort)
858: {
859: PC_ASM *osm = (PC_ASM *)pc->data;
861: PetscFunctionBegin;
862: osm->sort_indices = doSort;
863: PetscFunctionReturn(PETSC_SUCCESS);
864: }
866: static PetscErrorCode PCASMGetSubKSP_ASM(PC pc, PetscInt *n_local, PetscInt *first_local, KSP **ksp)
867: {
868: PC_ASM *osm = (PC_ASM *)pc->data;
870: PetscFunctionBegin;
871: 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");
873: if (n_local) *n_local = osm->n_local_true;
874: if (first_local) {
875: PetscCallMPI(MPI_Scan(&osm->n_local_true, first_local, 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)pc)));
876: *first_local -= osm->n_local_true;
877: }
878: if (ksp) *ksp = osm->ksp;
879: PetscFunctionReturn(PETSC_SUCCESS);
880: }
882: static PetscErrorCode PCASMGetSubMatType_ASM(PC pc, MatType *sub_mat_type)
883: {
884: PC_ASM *osm = (PC_ASM *)pc->data;
886: PetscFunctionBegin;
888: PetscAssertPointer(sub_mat_type, 2);
889: *sub_mat_type = osm->sub_mat_type;
890: PetscFunctionReturn(PETSC_SUCCESS);
891: }
893: static PetscErrorCode PCASMSetSubMatType_ASM(PC pc, MatType sub_mat_type)
894: {
895: PC_ASM *osm = (PC_ASM *)pc->data;
897: PetscFunctionBegin;
899: PetscCall(PetscFree(osm->sub_mat_type));
900: PetscCall(PetscStrallocpy(sub_mat_type, (char **)&osm->sub_mat_type));
901: PetscFunctionReturn(PETSC_SUCCESS);
902: }
904: /*@C
905: PCASMSetLocalSubdomains - Sets the local subdomains (for this processor only) for the additive Schwarz preconditioner `PCASM`.
907: Collective
909: Input Parameters:
910: + pc - the preconditioner context
911: . n - the number of subdomains for this processor (default value = 1)
912: . is - the index set that defines the subdomains for this processor
913: (or `NULL` for PETSc to determine subdomains)
914: - is_local - the index sets that define the local part of the subdomains for this processor, not used unless PCASMType is PC_ASM_RESTRICT
915: (or `NULL` to not provide these)
917: Options Database Key:
918: . -pc_asm_local_blocks <blks> - Sets number of local blocks
920: Level: advanced
922: Notes:
923: The `IS` numbering is in the parallel, global numbering of the vector for both is and is_local
925: By default the `PCASM` preconditioner uses 1 block per processor.
927: Use `PCASMSetTotalSubdomains()` to set the subdomains for all processors.
929: If is_local is provided and `PCASMType` is `PC_ASM_RESTRICT` then the solution only over the is_local region is interpolated
930: back to form the global solution (this is the standard restricted additive Schwarz method)
932: If the is_local is provided and `PCASMType` is `PC_ASM_INTERPOLATE` or `PC_ASM_NONE` then an error is generated since there is
933: no code to handle that case.
935: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
936: `PCASMCreateSubdomains2D()`, `PCASMGetLocalSubdomains()`, `PCASMType`, `PCASMSetType()`, `PCGASM`
937: @*/
938: PetscErrorCode PCASMSetLocalSubdomains(PC pc, PetscInt n, IS is[], IS is_local[])
939: {
940: PetscFunctionBegin;
942: PetscTryMethod(pc, "PCASMSetLocalSubdomains_C", (PC, PetscInt, IS[], IS[]), (pc, n, is, is_local));
943: PetscFunctionReturn(PETSC_SUCCESS);
944: }
946: /*@C
947: PCASMSetTotalSubdomains - Sets the subdomains for all processors for the
948: additive Schwarz preconditioner, `PCASM`.
950: Collective, all MPI ranks must pass in the same array of `IS`
952: Input Parameters:
953: + pc - the preconditioner context
954: . N - the number of subdomains for all processors
955: . is - the index sets that define the subdomains for all processors
956: (or `NULL` to ask PETSc to determine the subdomains)
957: - is_local - the index sets that define the local part of the subdomains for this processor
958: (or `NULL` to not provide this information)
960: Options Database Key:
961: . -pc_asm_blocks <blks> - Sets total blocks
963: Level: advanced
965: Notes:
966: Currently you cannot use this to set the actual subdomains with the argument is or is_local.
968: By default the `PCASM` preconditioner uses 1 block per processor.
970: These index sets cannot be destroyed until after completion of the
971: linear solves for which the `PCASM` preconditioner is being used.
973: Use `PCASMSetLocalSubdomains()` to set local subdomains.
975: The `IS` numbering is in the parallel, global numbering of the vector for both is and is_local
977: .seealso: [](ch_ksp), `PCASM`, `PCASMSetLocalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
978: `PCASMCreateSubdomains2D()`, `PCGASM`
979: @*/
980: PetscErrorCode PCASMSetTotalSubdomains(PC pc, PetscInt N, IS is[], IS is_local[])
981: {
982: PetscFunctionBegin;
984: PetscTryMethod(pc, "PCASMSetTotalSubdomains_C", (PC, PetscInt, IS[], IS[]), (pc, N, is, is_local));
985: PetscFunctionReturn(PETSC_SUCCESS);
986: }
988: /*@
989: PCASMSetOverlap - Sets the overlap between a pair of subdomains for the
990: additive Schwarz preconditioner, `PCASM`.
992: Logically Collective
994: Input Parameters:
995: + pc - the preconditioner context
996: - ovl - the amount of overlap between subdomains (ovl >= 0, default value = 1)
998: Options Database Key:
999: . -pc_asm_overlap <ovl> - Sets overlap
1001: Level: intermediate
1003: Notes:
1004: By default the `PCASM` preconditioner uses 1 block per processor. To use
1005: multiple blocks per perocessor, see `PCASMSetTotalSubdomains()` and
1006: `PCASMSetLocalSubdomains()` (and the option -pc_asm_blocks <blks>).
1008: The overlap defaults to 1, so if one desires that no additional
1009: overlap be computed beyond what may have been set with a call to
1010: `PCASMSetTotalSubdomains()` or `PCASMSetLocalSubdomains()`, then ovl
1011: must be set to be 0. In particular, if one does not explicitly set
1012: the subdomains an application code, then all overlap would be computed
1013: internally by PETSc, and using an overlap of 0 would result in an `PCASM`
1014: variant that is equivalent to the block Jacobi preconditioner.
1016: The default algorithm used by PETSc to increase overlap is fast, but not scalable,
1017: use the option -mat_increase_overlap_scalable when the problem and number of processes is large.
1019: One can define initial index sets with any overlap via
1020: `PCASMSetLocalSubdomains()`; the routine
1021: `PCASMSetOverlap()` merely allows PETSc to extend that overlap further
1022: if desired.
1024: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetLocalSubdomains()`, `PCASMGetSubKSP()`,
1025: `PCASMCreateSubdomains2D()`, `PCASMGetLocalSubdomains()`, `MatIncreaseOverlap()`, `PCGASM`
1026: @*/
1027: PetscErrorCode PCASMSetOverlap(PC pc, PetscInt ovl)
1028: {
1029: PetscFunctionBegin;
1032: PetscTryMethod(pc, "PCASMSetOverlap_C", (PC, PetscInt), (pc, ovl));
1033: PetscFunctionReturn(PETSC_SUCCESS);
1034: }
1036: /*@
1037: PCASMSetType - Sets the type of restriction and interpolation used
1038: for local problems in the additive Schwarz method, `PCASM`.
1040: Logically Collective
1042: Input Parameters:
1043: + pc - the preconditioner context
1044: - type - variant of `PCASM`, one of
1045: .vb
1046: PC_ASM_BASIC - full interpolation and restriction
1047: PC_ASM_RESTRICT - full restriction, local processor interpolation (default)
1048: PC_ASM_INTERPOLATE - full interpolation, local processor restriction
1049: PC_ASM_NONE - local processor restriction and interpolation
1050: .ve
1052: Options Database Key:
1053: . -pc_asm_type [basic,restrict,interpolate,none] - Sets `PCASMType`
1055: Level: intermediate
1057: Note:
1058: if the is_local arguments are passed to `PCASMSetLocalSubdomains()` then they are used when `PC_ASM_RESTRICT` has been selected
1059: to limit the local processor interpolation
1061: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMGetSubKSP()`,
1062: `PCASMCreateSubdomains2D()`, `PCASMType`, `PCASMSetLocalType()`, `PCASMGetLocalType()`, `PCGASM`
1063: @*/
1064: PetscErrorCode PCASMSetType(PC pc, PCASMType type)
1065: {
1066: PetscFunctionBegin;
1069: PetscTryMethod(pc, "PCASMSetType_C", (PC, PCASMType), (pc, type));
1070: PetscFunctionReturn(PETSC_SUCCESS);
1071: }
1073: /*@
1074: PCASMGetType - Gets the type of restriction and interpolation used
1075: for local problems in the additive Schwarz method, `PCASM`.
1077: Logically Collective
1079: Input Parameter:
1080: . pc - the preconditioner context
1082: Output Parameter:
1083: . type - variant of `PCASM`, one of
1084: .vb
1085: PC_ASM_BASIC - full interpolation and restriction
1086: PC_ASM_RESTRICT - full restriction, local processor interpolation
1087: PC_ASM_INTERPOLATE - full interpolation, local processor restriction
1088: PC_ASM_NONE - local processor restriction and interpolation
1089: .ve
1091: Options Database Key:
1092: . -pc_asm_type [basic,restrict,interpolate,none] - Sets `PCASM` type
1094: Level: intermediate
1096: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMGetSubKSP()`, `PCGASM`,
1097: `PCASMCreateSubdomains2D()`, `PCASMType`, `PCASMSetType()`, `PCASMSetLocalType()`, `PCASMGetLocalType()`
1098: @*/
1099: PetscErrorCode PCASMGetType(PC pc, PCASMType *type)
1100: {
1101: PetscFunctionBegin;
1103: PetscUseMethod(pc, "PCASMGetType_C", (PC, PCASMType *), (pc, type));
1104: PetscFunctionReturn(PETSC_SUCCESS);
1105: }
1107: /*@
1108: PCASMSetLocalType - Sets the type of composition used for local problems in the additive Schwarz method, `PCASM`.
1110: Logically Collective
1112: Input Parameters:
1113: + pc - the preconditioner context
1114: - type - type of composition, one of
1115: .vb
1116: PC_COMPOSITE_ADDITIVE - local additive combination
1117: PC_COMPOSITE_MULTIPLICATIVE - local multiplicative combination
1118: .ve
1120: Options Database Key:
1121: . -pc_asm_local_type [additive,multiplicative] - Sets local solver composition type
1123: Level: intermediate
1125: .seealso: [](ch_ksp), `PCASM`, `PCASMSetType()`, `PCASMGetType()`, `PCASMGetLocalType()`, `PCASMType`, `PCCompositeType`
1126: @*/
1127: PetscErrorCode PCASMSetLocalType(PC pc, PCCompositeType type)
1128: {
1129: PetscFunctionBegin;
1132: PetscTryMethod(pc, "PCASMSetLocalType_C", (PC, PCCompositeType), (pc, type));
1133: PetscFunctionReturn(PETSC_SUCCESS);
1134: }
1136: /*@
1137: PCASMGetLocalType - Gets the type of composition used for local problems in the additive Schwarz method, `PCASM`.
1139: Logically Collective
1141: Input Parameter:
1142: . pc - the preconditioner context
1144: Output Parameter:
1145: . type - type of composition, one of
1146: .vb
1147: PC_COMPOSITE_ADDITIVE - local additive combination
1148: PC_COMPOSITE_MULTIPLICATIVE - local multiplicative combination
1149: .ve
1151: Options Database Key:
1152: . -pc_asm_local_type [additive,multiplicative] - Sets local solver composition type
1154: Level: intermediate
1156: .seealso: [](ch_ksp), `PCASM`, `PCASMSetType()`, `PCASMGetType()`, `PCASMSetLocalType()`, `PCASMCreate()`, `PCASMType`, `PCCompositeType`
1157: @*/
1158: PetscErrorCode PCASMGetLocalType(PC pc, PCCompositeType *type)
1159: {
1160: PetscFunctionBegin;
1162: PetscAssertPointer(type, 2);
1163: PetscUseMethod(pc, "PCASMGetLocalType_C", (PC, PCCompositeType *), (pc, type));
1164: PetscFunctionReturn(PETSC_SUCCESS);
1165: }
1167: /*@
1168: PCASMSetSortIndices - Determines whether subdomain indices are sorted.
1170: Logically Collective
1172: Input Parameters:
1173: + pc - the preconditioner context
1174: - doSort - sort the subdomain indices
1176: Level: intermediate
1178: .seealso: [](ch_ksp), `PCASM`, `PCASMSetLocalSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMGetSubKSP()`,
1179: `PCASMCreateSubdomains2D()`
1180: @*/
1181: PetscErrorCode PCASMSetSortIndices(PC pc, PetscBool doSort)
1182: {
1183: PetscFunctionBegin;
1186: PetscTryMethod(pc, "PCASMSetSortIndices_C", (PC, PetscBool), (pc, doSort));
1187: PetscFunctionReturn(PETSC_SUCCESS);
1188: }
1190: /*@C
1191: PCASMGetSubKSP - Gets the local `KSP` contexts for all blocks on
1192: this processor.
1194: Collective iff first_local is requested
1196: Input Parameter:
1197: . pc - the preconditioner context
1199: Output Parameters:
1200: + n_local - the number of blocks on this processor or NULL
1201: . first_local - the global number of the first block on this processor or NULL,
1202: all processors must request or all must pass NULL
1203: - ksp - the array of `KSP` contexts
1205: Level: advanced
1207: Notes:
1208: After `PCASMGetSubKSP()` the array of `KSP`s is not to be freed.
1210: You must call `KSPSetUp()` before calling `PCASMGetSubKSP()`.
1212: Fortran Notes:
1213: The output argument 'ksp' must be an array of sufficient length or `PETSC_NULL_KSP`. The latter can be used to learn the necessary length.
1215: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`,
1216: `PCASMCreateSubdomains2D()`,
1217: @*/
1218: PetscErrorCode PCASMGetSubKSP(PC pc, PetscInt *n_local, PetscInt *first_local, KSP *ksp[])
1219: {
1220: PetscFunctionBegin;
1222: PetscUseMethod(pc, "PCASMGetSubKSP_C", (PC, PetscInt *, PetscInt *, KSP **), (pc, n_local, first_local, ksp));
1223: PetscFunctionReturn(PETSC_SUCCESS);
1224: }
1226: /*MC
1227: PCASM - Use the (restricted) additive Schwarz method, each block is (approximately) solved with
1228: its own `KSP` object, {cite}`dryja1987additive` and {cite}`1sbg`
1230: Options Database Keys:
1231: + -pc_asm_blocks <blks> - Sets total blocks. Defaults to one block per MPI process.
1232: . -pc_asm_overlap <ovl> - Sets overlap
1233: . -pc_asm_type [basic,restrict,interpolate,none] - Sets `PCASMType`, default is restrict. See `PCASMSetType()`
1234: - -pc_asm_local_type [additive, multiplicative] - Sets `PCCompositeType`, default is additive. See `PCASMSetLocalType()`
1236: Level: beginner
1238: Notes:
1239: If you run with, for example, 3 blocks on 1 processor or 3 blocks on 3 processors you
1240: will get a different convergence rate due to the default option of -pc_asm_type restrict. Use
1241: -pc_asm_type basic to get the same convergence behavior
1243: Each processor can have one or more blocks, but a block cannot be shared by more
1244: than one processor. Use `PCGASM` for subdomains shared by multiple processes.
1246: To set options on the solvers for each block append -sub_ to all the `KSP`, and `PC`
1247: options database keys. For example, -sub_pc_type ilu -sub_pc_factor_levels 1 -sub_ksp_type preonly
1249: To set the options on the solvers separate for each block call `PCASMGetSubKSP()`
1250: and set the options directly on the resulting `KSP` object (you can access its `PC` with `KSPGetPC()`)
1252: .seealso: [](ch_ksp), `PCCreate()`, `PCSetType()`, `PCType`, `PC`, `PCASMType`, `PCCompositeType`,
1253: `PCBJACOBI`, `PCASMGetSubKSP()`, `PCASMSetLocalSubdomains()`, `PCASMType`, `PCASMGetType()`, `PCASMSetLocalType()`, `PCASMGetLocalType()`
1254: `PCASMSetTotalSubdomains()`, `PCSetModifySubMatrices()`, `PCASMSetOverlap()`, `PCASMSetType()`, `PCCompositeType`
1255: M*/
1257: PETSC_EXTERN PetscErrorCode PCCreate_ASM(PC pc)
1258: {
1259: PC_ASM *osm;
1261: PetscFunctionBegin;
1262: PetscCall(PetscNew(&osm));
1264: osm->n = PETSC_DECIDE;
1265: osm->n_local = 0;
1266: osm->n_local_true = PETSC_DECIDE;
1267: osm->overlap = 1;
1268: osm->ksp = NULL;
1269: osm->restriction = NULL;
1270: osm->lprolongation = NULL;
1271: osm->lrestriction = NULL;
1272: osm->x = NULL;
1273: osm->y = NULL;
1274: osm->is = NULL;
1275: osm->is_local = NULL;
1276: osm->mat = NULL;
1277: osm->pmat = NULL;
1278: osm->type = PC_ASM_RESTRICT;
1279: osm->loctype = PC_COMPOSITE_ADDITIVE;
1280: osm->sort_indices = PETSC_TRUE;
1281: osm->dm_subdomains = PETSC_FALSE;
1282: osm->sub_mat_type = NULL;
1284: pc->data = (void *)osm;
1285: pc->ops->apply = PCApply_ASM;
1286: pc->ops->matapply = PCMatApply_ASM;
1287: pc->ops->applytranspose = PCApplyTranspose_ASM;
1288: pc->ops->setup = PCSetUp_ASM;
1289: pc->ops->reset = PCReset_ASM;
1290: pc->ops->destroy = PCDestroy_ASM;
1291: pc->ops->setfromoptions = PCSetFromOptions_ASM;
1292: pc->ops->setuponblocks = PCSetUpOnBlocks_ASM;
1293: pc->ops->view = PCView_ASM;
1294: pc->ops->applyrichardson = NULL;
1296: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalSubdomains_C", PCASMSetLocalSubdomains_ASM));
1297: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetTotalSubdomains_C", PCASMSetTotalSubdomains_ASM));
1298: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetOverlap_C", PCASMSetOverlap_ASM));
1299: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetType_C", PCASMSetType_ASM));
1300: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetType_C", PCASMGetType_ASM));
1301: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetLocalType_C", PCASMSetLocalType_ASM));
1302: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetLocalType_C", PCASMGetLocalType_ASM));
1303: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSortIndices_C", PCASMSetSortIndices_ASM));
1304: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubKSP_C", PCASMGetSubKSP_ASM));
1305: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMGetSubMatType_C", PCASMGetSubMatType_ASM));
1306: PetscCall(PetscObjectComposeFunction((PetscObject)pc, "PCASMSetSubMatType_C", PCASMSetSubMatType_ASM));
1307: PetscFunctionReturn(PETSC_SUCCESS);
1308: }
1310: /*@C
1311: PCASMCreateSubdomains - Creates the index sets for the overlapping Schwarz
1312: preconditioner, `PCASM`, for any problem on a general grid.
1314: Collective
1316: Input Parameters:
1317: + A - The global matrix operator
1318: - n - the number of local blocks
1320: Output Parameter:
1321: . outis - the array of index sets defining the subdomains
1323: Level: advanced
1325: Note:
1326: This generates nonoverlapping subdomains; the `PCASM` will generate the overlap
1327: from these if you use `PCASMSetLocalSubdomains()`
1329: Fortran Notes:
1330: You must provide the array outis[] already allocated of length n.
1332: .seealso: [](ch_ksp), `PCASM`, `PCASMSetLocalSubdomains()`, `PCASMDestroySubdomains()`
1333: @*/
1334: PetscErrorCode PCASMCreateSubdomains(Mat A, PetscInt n, IS *outis[])
1335: {
1336: MatPartitioning mpart;
1337: const char *prefix;
1338: PetscInt i, j, rstart, rend, bs;
1339: PetscBool hasop, isbaij = PETSC_FALSE, foundpart = PETSC_FALSE;
1340: Mat Ad = NULL, adj;
1341: IS ispart, isnumb, *is;
1343: PetscFunctionBegin;
1345: PetscAssertPointer(outis, 3);
1346: PetscCheck(n >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "number of local blocks must be > 0, n = %" PetscInt_FMT, n);
1348: /* Get prefix, row distribution, and block size */
1349: PetscCall(MatGetOptionsPrefix(A, &prefix));
1350: PetscCall(MatGetOwnershipRange(A, &rstart, &rend));
1351: PetscCall(MatGetBlockSize(A, &bs));
1352: 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);
1354: /* Get diagonal block from matrix if possible */
1355: PetscCall(MatHasOperation(A, MATOP_GET_DIAGONAL_BLOCK, &hasop));
1356: if (hasop) PetscCall(MatGetDiagonalBlock(A, &Ad));
1357: if (Ad) {
1358: PetscCall(PetscObjectBaseTypeCompare((PetscObject)Ad, MATSEQBAIJ, &isbaij));
1359: if (!isbaij) PetscCall(PetscObjectBaseTypeCompare((PetscObject)Ad, MATSEQSBAIJ, &isbaij));
1360: }
1361: if (Ad && n > 1) {
1362: PetscBool match, done;
1363: /* Try to setup a good matrix partitioning if available */
1364: PetscCall(MatPartitioningCreate(PETSC_COMM_SELF, &mpart));
1365: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)mpart, prefix));
1366: PetscCall(MatPartitioningSetFromOptions(mpart));
1367: PetscCall(PetscObjectTypeCompare((PetscObject)mpart, MATPARTITIONINGCURRENT, &match));
1368: if (!match) PetscCall(PetscObjectTypeCompare((PetscObject)mpart, MATPARTITIONINGSQUARE, &match));
1369: if (!match) { /* assume a "good" partitioner is available */
1370: PetscInt na;
1371: const PetscInt *ia, *ja;
1372: PetscCall(MatGetRowIJ(Ad, 0, PETSC_TRUE, isbaij, &na, &ia, &ja, &done));
1373: if (done) {
1374: /* Build adjacency matrix by hand. Unfortunately a call to
1375: MatConvert(Ad,MATMPIADJ,MAT_INITIAL_MATRIX,&adj) will
1376: remove the block-aij structure and we cannot expect
1377: MatPartitioning to split vertices as we need */
1378: PetscInt i, j, len, nnz, cnt, *iia = NULL, *jja = NULL;
1379: const PetscInt *row;
1380: nnz = 0;
1381: for (i = 0; i < na; i++) { /* count number of nonzeros */
1382: len = ia[i + 1] - ia[i];
1383: row = ja + ia[i];
1384: for (j = 0; j < len; j++) {
1385: if (row[j] == i) { /* don't count diagonal */
1386: len--;
1387: break;
1388: }
1389: }
1390: nnz += len;
1391: }
1392: PetscCall(PetscMalloc1(na + 1, &iia));
1393: PetscCall(PetscMalloc1(nnz, &jja));
1394: nnz = 0;
1395: iia[0] = 0;
1396: for (i = 0; i < na; i++) { /* fill adjacency */
1397: cnt = 0;
1398: len = ia[i + 1] - ia[i];
1399: row = ja + ia[i];
1400: for (j = 0; j < len; j++) {
1401: if (row[j] != i) { /* if not diagonal */
1402: jja[nnz + cnt++] = row[j];
1403: }
1404: }
1405: nnz += cnt;
1406: iia[i + 1] = nnz;
1407: }
1408: /* Partitioning of the adjacency matrix */
1409: PetscCall(MatCreateMPIAdj(PETSC_COMM_SELF, na, na, iia, jja, NULL, &adj));
1410: PetscCall(MatPartitioningSetAdjacency(mpart, adj));
1411: PetscCall(MatPartitioningSetNParts(mpart, n));
1412: PetscCall(MatPartitioningApply(mpart, &ispart));
1413: PetscCall(ISPartitioningToNumbering(ispart, &isnumb));
1414: PetscCall(MatDestroy(&adj));
1415: foundpart = PETSC_TRUE;
1416: }
1417: PetscCall(MatRestoreRowIJ(Ad, 0, PETSC_TRUE, isbaij, &na, &ia, &ja, &done));
1418: }
1419: PetscCall(MatPartitioningDestroy(&mpart));
1420: }
1422: PetscCall(PetscMalloc1(n, &is));
1423: *outis = is;
1425: if (!foundpart) {
1426: /* Partitioning by contiguous chunks of rows */
1428: PetscInt mbs = (rend - rstart) / bs;
1429: PetscInt start = rstart;
1430: for (i = 0; i < n; i++) {
1431: PetscInt count = (mbs / n + ((mbs % n) > i)) * bs;
1432: PetscCall(ISCreateStride(PETSC_COMM_SELF, count, start, 1, &is[i]));
1433: start += count;
1434: }
1436: } else {
1437: /* Partitioning by adjacency of diagonal block */
1439: const PetscInt *numbering;
1440: PetscInt *count, nidx, *indices, *newidx, start = 0;
1441: /* Get node count in each partition */
1442: PetscCall(PetscMalloc1(n, &count));
1443: PetscCall(ISPartitioningCount(ispart, n, count));
1444: if (isbaij && bs > 1) { /* adjust for the block-aij case */
1445: for (i = 0; i < n; i++) count[i] *= bs;
1446: }
1447: /* Build indices from node numbering */
1448: PetscCall(ISGetLocalSize(isnumb, &nidx));
1449: PetscCall(PetscMalloc1(nidx, &indices));
1450: for (i = 0; i < nidx; i++) indices[i] = i; /* needs to be initialized */
1451: PetscCall(ISGetIndices(isnumb, &numbering));
1452: PetscCall(PetscSortIntWithPermutation(nidx, numbering, indices));
1453: PetscCall(ISRestoreIndices(isnumb, &numbering));
1454: if (isbaij && bs > 1) { /* adjust for the block-aij case */
1455: PetscCall(PetscMalloc1(nidx * bs, &newidx));
1456: for (i = 0; i < nidx; i++) {
1457: for (j = 0; j < bs; j++) newidx[i * bs + j] = indices[i] * bs + j;
1458: }
1459: PetscCall(PetscFree(indices));
1460: nidx *= bs;
1461: indices = newidx;
1462: }
1463: /* Shift to get global indices */
1464: for (i = 0; i < nidx; i++) indices[i] += rstart;
1466: /* Build the index sets for each block */
1467: for (i = 0; i < n; i++) {
1468: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, count[i], &indices[start], PETSC_COPY_VALUES, &is[i]));
1469: PetscCall(ISSort(is[i]));
1470: start += count[i];
1471: }
1473: PetscCall(PetscFree(count));
1474: PetscCall(PetscFree(indices));
1475: PetscCall(ISDestroy(&isnumb));
1476: PetscCall(ISDestroy(&ispart));
1477: }
1478: PetscFunctionReturn(PETSC_SUCCESS);
1479: }
1481: /*@C
1482: PCASMDestroySubdomains - Destroys the index sets created with
1483: `PCASMCreateSubdomains()`. Should be called after setting subdomains with `PCASMSetLocalSubdomains()`.
1485: Collective
1487: Input Parameters:
1488: + n - the number of index sets
1489: . is - the array of index sets
1490: - is_local - the array of local index sets, can be `NULL`
1492: Level: advanced
1494: .seealso: [](ch_ksp), `PCASM`, `PCASMCreateSubdomains()`, `PCASMSetLocalSubdomains()`
1495: @*/
1496: PetscErrorCode PCASMDestroySubdomains(PetscInt n, IS is[], IS is_local[])
1497: {
1498: PetscInt i;
1500: PetscFunctionBegin;
1501: if (n <= 0) PetscFunctionReturn(PETSC_SUCCESS);
1502: if (is) {
1503: PetscAssertPointer(is, 2);
1504: for (i = 0; i < n; i++) PetscCall(ISDestroy(&is[i]));
1505: PetscCall(PetscFree(is));
1506: }
1507: if (is_local) {
1508: PetscAssertPointer(is_local, 3);
1509: for (i = 0; i < n; i++) PetscCall(ISDestroy(&is_local[i]));
1510: PetscCall(PetscFree(is_local));
1511: }
1512: PetscFunctionReturn(PETSC_SUCCESS);
1513: }
1515: /*@C
1516: PCASMCreateSubdomains2D - Creates the index sets for the overlapping Schwarz
1517: preconditioner, `PCASM`, for a two-dimensional problem on a regular grid.
1519: Not Collective
1521: Input Parameters:
1522: + m - the number of mesh points in the x direction
1523: . n - the number of mesh points in the y direction
1524: . M - the number of subdomains in the x direction
1525: . N - the number of subdomains in the y direction
1526: . dof - degrees of freedom per node
1527: - overlap - overlap in mesh lines
1529: Output Parameters:
1530: + Nsub - the number of subdomains created
1531: . is - array of index sets defining overlapping (if overlap > 0) subdomains
1532: - is_local - array of index sets defining non-overlapping subdomains
1534: Level: advanced
1536: Note:
1537: Presently `PCAMSCreateSubdomains2d()` is valid only for sequential
1538: preconditioners. More general related routines are
1539: `PCASMSetTotalSubdomains()` and `PCASMSetLocalSubdomains()`.
1541: Fortran Notes:
1542: The `IS` must be declared as an array of length long enough to hold `Nsub` entries
1544: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetLocalSubdomains()`, `PCASMGetSubKSP()`,
1545: `PCASMSetOverlap()`
1546: @*/
1547: PetscErrorCode PCASMCreateSubdomains2D(PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscInt dof, PetscInt overlap, PetscInt *Nsub, IS **is, IS **is_local)
1548: {
1549: PetscInt i, j, height, width, ystart, xstart, yleft, yright, xleft, xright, loc_outer;
1550: PetscInt nidx, *idx, loc, ii, jj, count;
1552: PetscFunctionBegin;
1553: PetscCheck(dof == 1, PETSC_COMM_SELF, PETSC_ERR_SUP, "dof must be 1");
1555: *Nsub = N * M;
1556: PetscCall(PetscMalloc1(*Nsub, is));
1557: PetscCall(PetscMalloc1(*Nsub, is_local));
1558: ystart = 0;
1559: loc_outer = 0;
1560: for (i = 0; i < N; i++) {
1561: height = n / N + ((n % N) > i); /* height of subdomain */
1562: PetscCheck(height >= 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many N subdomains for mesh dimension n");
1563: yleft = ystart - overlap;
1564: if (yleft < 0) yleft = 0;
1565: yright = ystart + height + overlap;
1566: if (yright > n) yright = n;
1567: xstart = 0;
1568: for (j = 0; j < M; j++) {
1569: width = m / M + ((m % M) > j); /* width of subdomain */
1570: PetscCheck(width >= 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many M subdomains for mesh dimension m");
1571: xleft = xstart - overlap;
1572: if (xleft < 0) xleft = 0;
1573: xright = xstart + width + overlap;
1574: if (xright > m) xright = m;
1575: nidx = (xright - xleft) * (yright - yleft);
1576: PetscCall(PetscMalloc1(nidx, &idx));
1577: loc = 0;
1578: for (ii = yleft; ii < yright; ii++) {
1579: count = m * ii + xleft;
1580: for (jj = xleft; jj < xright; jj++) idx[loc++] = count++;
1581: }
1582: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, nidx, idx, PETSC_COPY_VALUES, (*is) + loc_outer));
1583: if (overlap == 0) {
1584: PetscCall(PetscObjectReference((PetscObject)(*is)[loc_outer]));
1586: (*is_local)[loc_outer] = (*is)[loc_outer];
1587: } else {
1588: for (loc = 0, ii = ystart; ii < ystart + height; ii++) {
1589: for (jj = xstart; jj < xstart + width; jj++) idx[loc++] = m * ii + jj;
1590: }
1591: PetscCall(ISCreateGeneral(PETSC_COMM_SELF, loc, idx, PETSC_COPY_VALUES, *is_local + loc_outer));
1592: }
1593: PetscCall(PetscFree(idx));
1594: xstart += width;
1595: loc_outer++;
1596: }
1597: ystart += height;
1598: }
1599: for (i = 0; i < *Nsub; i++) PetscCall(ISSort((*is)[i]));
1600: PetscFunctionReturn(PETSC_SUCCESS);
1601: }
1603: /*@C
1604: PCASMGetLocalSubdomains - Gets the local subdomains (for this processor
1605: only) for the additive Schwarz preconditioner, `PCASM`.
1607: Not Collective
1609: Input Parameter:
1610: . pc - the preconditioner context
1612: Output Parameters:
1613: + n - if requested, the number of subdomains for this processor (default value = 1)
1614: . is - if requested, the index sets that define the subdomains for this processor
1615: - is_local - if requested, the index sets that define the local part of the subdomains for this processor (can be `NULL`)
1617: Level: advanced
1619: Note:
1620: The `IS` numbering is in the parallel, global numbering of the vector.
1622: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
1623: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubmatrices()`
1624: @*/
1625: PetscErrorCode PCASMGetLocalSubdomains(PC pc, PetscInt *n, IS *is[], IS *is_local[])
1626: {
1627: PC_ASM *osm = (PC_ASM *)pc->data;
1628: PetscBool match;
1630: PetscFunctionBegin;
1632: if (n) PetscAssertPointer(n, 2);
1633: if (is) PetscAssertPointer(is, 3);
1634: if (is_local) PetscAssertPointer(is_local, 4);
1635: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1636: PetscCheck(match, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "PC is not a PCASM");
1637: if (n) *n = osm->n_local_true;
1638: if (is) *is = osm->is;
1639: if (is_local) *is_local = osm->is_local;
1640: PetscFunctionReturn(PETSC_SUCCESS);
1641: }
1643: /*@C
1644: PCASMGetLocalSubmatrices - Gets the local submatrices (for this processor
1645: only) for the additive Schwarz preconditioner, `PCASM`.
1647: Not Collective
1649: Input Parameter:
1650: . pc - the preconditioner context
1652: Output Parameters:
1653: + n - if requested, the number of matrices for this processor (default value = 1)
1654: - mat - if requested, the matrices
1656: Level: advanced
1658: Notes:
1659: Call after `PCSetUp()` (or `KSPSetUp()`) but before `PCApply()` and before `PCSetUpOnBlocks()`)
1661: Usually one would use `PCSetModifySubMatrices()` to change the submatrices in building the preconditioner.
1663: .seealso: [](ch_ksp), `PCASM`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`, `PCASMGetSubKSP()`,
1664: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`, `PCSetModifySubMatrices()`
1665: @*/
1666: PetscErrorCode PCASMGetLocalSubmatrices(PC pc, PetscInt *n, Mat *mat[])
1667: {
1668: PC_ASM *osm;
1669: PetscBool match;
1671: PetscFunctionBegin;
1673: if (n) PetscAssertPointer(n, 2);
1674: if (mat) PetscAssertPointer(mat, 3);
1675: PetscCheck(pc->setupcalled, PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONGSTATE, "Must call after KSPSetUp() or PCSetUp().");
1676: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1677: if (!match) {
1678: if (n) *n = 0;
1679: if (mat) *mat = NULL;
1680: } else {
1681: osm = (PC_ASM *)pc->data;
1682: if (n) *n = osm->n_local_true;
1683: if (mat) *mat = osm->pmat;
1684: }
1685: PetscFunctionReturn(PETSC_SUCCESS);
1686: }
1688: /*@
1689: PCASMSetDMSubdomains - Indicates whether to use `DMCreateDomainDecomposition()` to define the subdomains, whenever possible.
1691: Logically Collective
1693: Input Parameters:
1694: + pc - the preconditioner
1695: - flg - boolean indicating whether to use subdomains defined by the `DM`
1697: Options Database Key:
1698: . -pc_asm_dm_subdomains <bool> - use subdomains defined by the `DM`
1700: Level: intermediate
1702: Note:
1703: `PCASMSetTotalSubdomains()` and `PCASMSetOverlap()` take precedence over `PCASMSetDMSubdomains()`,
1704: so setting either of the first two effectively turns the latter off.
1706: .seealso: [](ch_ksp), `PCASM`, `PCASMGetDMSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`
1707: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`
1708: @*/
1709: PetscErrorCode PCASMSetDMSubdomains(PC pc, PetscBool flg)
1710: {
1711: PC_ASM *osm = (PC_ASM *)pc->data;
1712: PetscBool match;
1714: PetscFunctionBegin;
1717: PetscCheck(!pc->setupcalled, ((PetscObject)pc)->comm, PETSC_ERR_ARG_WRONGSTATE, "Not for a setup PC.");
1718: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1719: if (match) osm->dm_subdomains = flg;
1720: PetscFunctionReturn(PETSC_SUCCESS);
1721: }
1723: /*@
1724: PCASMGetDMSubdomains - Returns flag indicating whether to use `DMCreateDomainDecomposition()` to define the subdomains, whenever possible.
1726: Not Collective
1728: Input Parameter:
1729: . pc - the preconditioner
1731: Output Parameter:
1732: . flg - boolean indicating whether to use subdomains defined by the `DM`
1734: Level: intermediate
1736: .seealso: [](ch_ksp), `PCASM`, `PCASMSetDMSubdomains()`, `PCASMSetTotalSubdomains()`, `PCASMSetOverlap()`
1737: `PCASMCreateSubdomains2D()`, `PCASMSetLocalSubdomains()`, `PCASMGetLocalSubdomains()`
1738: @*/
1739: PetscErrorCode PCASMGetDMSubdomains(PC pc, PetscBool *flg)
1740: {
1741: PC_ASM *osm = (PC_ASM *)pc->data;
1742: PetscBool match;
1744: PetscFunctionBegin;
1746: PetscAssertPointer(flg, 2);
1747: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCASM, &match));
1748: if (match) *flg = osm->dm_subdomains;
1749: else *flg = PETSC_FALSE;
1750: PetscFunctionReturn(PETSC_SUCCESS);
1751: }
1753: /*@C
1754: PCASMGetSubMatType - Gets the matrix type used for `PCASM` subsolves, as a string.
1756: Not Collective
1758: Input Parameter:
1759: . pc - the `PC`
1761: Output Parameter:
1762: . sub_mat_type - name of matrix type
1764: Level: advanced
1766: .seealso: [](ch_ksp), `PCASM`, `PCASMSetSubMatType()`, `PCSetType()`, `VecSetType()`, `MatType`, `Mat`
1767: @*/
1768: PetscErrorCode PCASMGetSubMatType(PC pc, MatType *sub_mat_type)
1769: {
1770: PetscFunctionBegin;
1772: PetscTryMethod(pc, "PCASMGetSubMatType_C", (PC, MatType *), (pc, sub_mat_type));
1773: PetscFunctionReturn(PETSC_SUCCESS);
1774: }
1776: /*@C
1777: PCASMSetSubMatType - Set the type of matrix used for `PCASM` subsolves
1779: Collective
1781: Input Parameters:
1782: + pc - the `PC` object
1783: - sub_mat_type - the `MatType`
1785: Options Database Key:
1786: . -pc_asm_sub_mat_type <sub_mat_type> - Sets the matrix type used for subsolves, for example, seqaijviennacl.
1787: If you specify a base name like aijviennacl, the corresponding sequential type is assumed.
1789: Note:
1790: See `MatType` for available types
1792: Level: advanced
1794: .seealso: [](ch_ksp), `PCASM`, `PCASMGetSubMatType()`, `PCSetType()`, `VecSetType()`, `MatType`, `Mat`
1795: @*/
1796: PetscErrorCode PCASMSetSubMatType(PC pc, MatType sub_mat_type)
1797: {
1798: PetscFunctionBegin;
1800: PetscTryMethod(pc, "PCASMSetSubMatType_C", (PC, MatType), (pc, sub_mat_type));
1801: PetscFunctionReturn(PETSC_SUCCESS);
1802: }