xref: /petsc/src/ksp/pc/impls/mg/gdsw.c (revision ad781fe3223b515d45fb60062f8062326362e786)
1 #include <petsc/private/pcmgimpl.h>
2 #include <petsc/private/pcbddcimpl.h>
3 #include <petsc/private/pcbddcprivateimpl.h>
4 
PCMGGDSWSetUp(PC pc,PetscInt l,DM dm,KSP smooth,PetscInt Nc,Mat A,PetscInt * ns,Mat ** sA_IG_n,KSP ** sksp_n,IS ** sI_n,IS ** sG_n,Mat ** sGf_n,IS ** sGi_n,IS ** sGiM_n)5 static PetscErrorCode PCMGGDSWSetUp(PC pc, PetscInt l, DM dm, KSP smooth, PetscInt Nc, Mat A, PetscInt *ns, Mat **sA_IG_n, KSP **sksp_n, IS **sI_n, IS **sG_n, Mat **sGf_n, IS **sGi_n, IS **sGiM_n)
6 {
7   KSP                   *sksp;
8   PC                     pcbddc = NULL, smoothpc;
9   PC_BDDC               *ipcbddc;
10   PC_IS                 *ipcis;
11   Mat                   *sA_IG, *sGf, cmat, lA;
12   ISLocalToGlobalMapping l2g;
13   IS                    *sI, *sG, *sGi, *sGiM, cref;
14   PCBDDCSubSchurs        sub_schurs = NULL;
15   PCBDDCGraph            graph;
16   const char            *prefix;
17   const PetscScalar     *tdata;
18   PetscScalar           *data, *cdata;
19   PetscReal              tol = 0.0, otol;
20   const PetscInt        *ia, *ja;
21   PetscInt              *ccii, *cridx;
22   PetscInt               i, j, ngct, ng, dbg = 0, odbg, minmax[2] = {0, PETSC_INT_MAX}, ominmax[2], vsize;
23   PetscBool              flg, userdefined = PETSC_TRUE, reuse_solver = PETSC_TRUE, reduced = PETSC_FALSE;
24 
25   PetscFunctionBegin;
26   PetscCall(MatGetBlockSize(A, &vsize));
27   PetscCall(KSPGetOptionsPrefix(smooth, &prefix));
28   PetscOptionsBegin(PetscObjectComm((PetscObject)smooth), prefix, "GDSW options", "PC");
29   PetscCall(PetscOptionsReal("-gdsw_tolerance", "Tolerance for eigenvalue problem", NULL, tol, &tol, NULL));
30   PetscCall(PetscOptionsBool("-gdsw_userdefined", "Use user-defined functions in addition to those adaptively generated", NULL, userdefined, &userdefined, NULL));
31   PetscCall(PetscOptionsIntArray("-gdsw_minmax", "Minimum and maximum number of basis functions per connected component for adaptive GDSW", NULL, minmax, (i = 2, &i), NULL));
32   PetscCall(PetscOptionsInt("-gdsw_vertex_size", "Connected components smaller or equal to vertex size will be considered as vertices", NULL, vsize, &vsize, NULL));
33   PetscCall(PetscOptionsBool("-gdsw_reuse", "Reuse interior solver from Schur complement computations", NULL, reuse_solver, &reuse_solver, NULL));
34   PetscCall(PetscOptionsBool("-gdsw_reduced", "Reduced GDSW", NULL, reduced, &reduced, NULL));
35   PetscCall(PetscOptionsInt("-gdsw_debug", "Debug output", NULL, dbg, &dbg, NULL));
36   PetscOptionsEnd();
37 
38   PetscCall(PetscObjectTypeCompare((PetscObject)A, MATIS, &flg));
39   if (!flg) {
40     MatNullSpace nnsp;
41 
42     PetscCall(MatGetNearNullSpace(A, &nnsp));
43     PetscCall(PetscObjectReference((PetscObject)nnsp));
44     PetscCall(MatConvert(A, MATIS, MAT_INITIAL_MATRIX, &A));
45     PetscCall(MatSetNearNullSpace(A, nnsp));
46     PetscCall(MatNullSpaceDestroy(&nnsp));
47   } else PetscCall(PetscObjectReference((PetscObject)A));
48 
49   /* TODO Multi sub */
50   *ns = 1;
51   PetscCall(PetscMalloc1(*ns, &sA_IG));
52   PetscCall(PetscMalloc1(*ns, &sksp));
53   PetscCall(PetscMalloc1(*ns, &sI));
54   PetscCall(PetscMalloc1(*ns, &sG));
55   PetscCall(PetscMalloc1(*ns, &sGf));
56   PetscCall(PetscMalloc1(*ns, &sGi));
57   PetscCall(PetscMalloc1(*ns, &sGiM));
58   *sA_IG_n = sA_IG;
59   *sksp_n  = sksp;
60   *sI_n    = sI;
61   *sG_n    = sG;
62   *sGf_n   = sGf;
63   *sGi_n   = sGi;
64   *sGiM_n  = sGiM;
65 
66   /* submatrices and solvers */
67   PetscCall(KSPGetPC(smooth, &smoothpc));
68   PetscCall(PetscObjectTypeCompareAny((PetscObject)smoothpc, &flg, PCBDDC, ""));
69   if (!flg) {
70     Mat smoothA;
71 
72     PetscCall(PCGetOperators(smoothpc, &smoothA, NULL));
73     PetscCall(PCCreate(PetscObjectComm((PetscObject)A), &pcbddc));
74     PetscCall(PCSetType(pcbddc, PCBDDC));
75     PetscCall(PCSetOperators(pcbddc, smoothA, A));
76     PetscCall(PCISSetUp(pcbddc, PETSC_TRUE, PETSC_FALSE));
77   } else {
78     PetscCall(PetscObjectReference((PetscObject)smoothpc));
79     pcbddc = smoothpc;
80   }
81   ipcis   = (PC_IS *)pcbddc->data;
82   ipcbddc = (PC_BDDC *)pcbddc->data;
83   PetscCall(PetscObjectReference((PetscObject)ipcis->A_IB));
84   PetscCall(PetscObjectReference((PetscObject)ipcis->is_I_global));
85   PetscCall(PetscObjectReference((PetscObject)ipcis->is_B_global));
86   sA_IG[0] = ipcis->A_IB;
87   sI[0]    = ipcis->is_I_global;
88   sG[0]    = ipcis->is_B_global;
89 
90   PetscCall(KSPCreate(PetscObjectComm((PetscObject)ipcis->A_II), &sksp[0]));
91   PetscCall(KSPSetNestLevel(sksp[0], pc->kspnestlevel));
92   PetscCall(KSPSetOperators(sksp[0], ipcis->A_II, ipcis->pA_II));
93   PetscCall(KSPSetOptionsPrefix(sksp[0], prefix));
94   PetscCall(KSPAppendOptionsPrefix(sksp[0], "gdsw_"));
95   PetscCall(KSPSetFromOptions(sksp[0]));
96 
97   /* analyze interface */
98   PetscCall(MatISGetLocalMat(A, &lA));
99   graph = ipcbddc->mat_graph;
100   if (!flg) {
101     PetscInt N;
102 
103     PetscCall(MatISGetLocalToGlobalMapping(A, &l2g, NULL));
104     PetscCall(MatGetSize(A, &N, NULL));
105     PetscCall(PCBDDCGraphInit(graph, l2g, N, PETSC_INT_MAX));
106     PetscCall(MatGetRowIJ(lA, 0, PETSC_TRUE, PETSC_FALSE, &graph->nvtxs_csr, (const PetscInt **)&graph->xadj, (const PetscInt **)&graph->adjncy, &flg));
107     PetscCall(PCBDDCGraphSetUp(graph, vsize, NULL, NULL, 0, NULL, NULL));
108     PetscCall(MatRestoreRowIJ(lA, 0, PETSC_TRUE, PETSC_FALSE, &graph->nvtxs_csr, (const PetscInt **)&graph->xadj, (const PetscInt **)&graph->adjncy, &flg));
109     PetscCall(PCBDDCGraphComputeConnectedComponents(graph));
110   }
111   l2g = graph->l2gmap;
112   if (reduced) {
113     PetscContainer        gcand;
114     PCBDDCGraphCandidates cand;
115     PetscErrorCode (*rgdsw)(DM, PetscInt *, IS **);
116 
117     PetscCall(PetscObjectQueryFunction((PetscObject)dm, "DMComputeLocalRGDSWSets", &rgdsw));
118     PetscCheck(rgdsw, PETSC_COMM_SELF, PETSC_ERR_SUP, "Not supported");
119     PetscCall(PetscNew(&cand));
120     PetscCall((*rgdsw)(dm, &cand->nfc, &cand->Faces));
121     /* filter interior (if any) and guarantee IS are ordered by global numbering */
122     for (i = 0; i < cand->nfc; i++) {
123       IS is, is2;
124 
125       PetscCall(ISLocalToGlobalMappingApplyIS(l2g, cand->Faces[i], &is));
126       PetscCall(ISDestroy(&cand->Faces[i]));
127       PetscCall(ISSort(is));
128       PetscCall(ISGlobalToLocalMappingApplyIS(l2g, IS_GTOLM_DROP, is, &is2));
129       PetscCall(ISDestroy(&is));
130       PetscCall(ISGlobalToLocalMappingApplyIS(ipcis->BtoNmap, IS_GTOLM_DROP, is2, &is));
131       PetscCall(ISDestroy(&is2));
132       PetscCall(ISLocalToGlobalMappingApplyIS(ipcis->BtoNmap, is, &cand->Faces[i]));
133       PetscCall(ISDestroy(&is));
134     }
135     PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &gcand));
136     PetscCall(PetscContainerSetPointer(gcand, cand));
137     PetscCall(PetscContainerSetCtxDestroy(gcand, PCBDDCDestroyGraphCandidatesIS));
138     PetscCall(PetscObjectCompose((PetscObject)l2g, "_PCBDDCGraphCandidatesIS", (PetscObject)gcand));
139     PetscCall(PetscContainerDestroy(&gcand));
140   }
141 
142   /* interface functions */
143   otol                           = ipcbddc->adaptive_threshold[1];
144   odbg                           = ipcbddc->dbg_flag;
145   ominmax[0]                     = ipcbddc->adaptive_nmin;
146   ominmax[1]                     = ipcbddc->adaptive_nmax;
147   ipcbddc->adaptive_threshold[1] = tol;
148   ipcbddc->dbg_flag              = dbg;
149   ipcbddc->adaptive_nmin         = minmax[0];
150   ipcbddc->adaptive_nmax         = minmax[1];
151   if (tol != 0.0) { /* adaptive */
152     Mat lS;
153 
154     PetscCall(MatCreateSchurComplement(ipcis->A_II, ipcis->pA_II, ipcis->A_IB, ipcis->A_BI, ipcis->A_BB, &lS));
155     PetscCall(KSPGetOptionsPrefix(sksp[0], &prefix));
156     PetscCall(PCBDDCSubSchursCreate(&sub_schurs));
157     PetscCall(PCBDDCSubSchursInit(sub_schurs, prefix, ipcis->is_I_local, ipcis->is_B_local, graph, ipcis->BtoNmap, PETSC_FALSE, PETSC_TRUE));
158     if (userdefined) PetscCall(PCBDDCComputeFakeChange(pcbddc, PETSC_FALSE, graph, NULL, &cmat, &cref, NULL, &flg));
159     else {
160       cmat = NULL;
161       cref = NULL;
162     }
163     PetscCall(PCBDDCSubSchursSetUp(sub_schurs, lA, lS, PETSC_TRUE, NULL, NULL, -1, NULL, PETSC_TRUE, reuse_solver, PETSC_FALSE, 0, NULL, NULL, cmat, cref));
164     PetscCall(MatDestroy(&lS));
165     PetscCall(MatDestroy(&cmat));
166     PetscCall(ISDestroy(&cref));
167     if (sub_schurs->reuse_solver) {
168       PetscCall(KSPSetPC(sksp[0], sub_schurs->reuse_solver->interior_solver));
169       PetscCall(PCDestroy(&sub_schurs->reuse_solver->interior_solver));
170       sub_schurs->reuse_solver = NULL;
171     }
172   }
173   PetscCall(PCBDDCComputeFakeChange(pcbddc, PETSC_TRUE, graph, sub_schurs, &cmat, &cref, &sGiM[0], NULL));
174   PetscCall(PCBDDCSubSchursDestroy(&sub_schurs));
175   ipcbddc->adaptive_threshold[1] = otol;
176   ipcbddc->dbg_flag              = odbg;
177   ipcbddc->adaptive_nmin         = ominmax[0];
178   ipcbddc->adaptive_nmax         = ominmax[1];
179 
180   PetscCall(ISLocalToGlobalMappingApplyIS(l2g, cref, &sGi[0]));
181   PetscCall(ISDestroy(&cref));
182 
183   PetscCall(MatSeqAIJGetArrayRead(cmat, &tdata));
184   PetscCall(MatGetRowIJ(cmat, 0, PETSC_FALSE, PETSC_FALSE, &ngct, &ia, &ja, &flg));
185   PetscCheck(flg, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Error in MatGetRowIJ");
186 
187   PetscCall(PetscMalloc1(ngct + 1, &ccii));
188   PetscCall(PetscMalloc1(ia[ngct], &cridx));
189   PetscCall(PetscMalloc1(ia[ngct], &cdata));
190 
191   PetscCall(PetscArraycpy(ccii, ia, ngct + 1));
192   PetscCall(PetscArraycpy(cdata, tdata, ia[ngct]));
193   PetscCall(ISGlobalToLocalMappingApply(ipcis->BtoNmap, IS_GTOLM_DROP, ia[ngct], ja, &i, cridx));
194   PetscCheck(i == ia[ngct], PETSC_COMM_SELF, PETSC_ERR_PLIB, "Error in G2L");
195 
196   PetscCall(MatRestoreRowIJ(cmat, 0, PETSC_FALSE, PETSC_FALSE, &i, &ia, &ja, &flg));
197   PetscCall(MatSeqAIJRestoreArrayRead(cmat, &tdata));
198   PetscCall(MatDestroy(&cmat));
199 
200   /* populate dense matrix */
201   PetscCall(ISGetLocalSize(sG[0], &ng));
202   PetscCall(MatCreateSeqDense(PETSC_COMM_SELF, ng, ngct, NULL, &sGf[0]));
203   PetscCall(MatDenseGetArrayWrite(sGf[0], &data));
204   for (i = 0; i < ngct; i++)
205     for (j = ccii[i]; j < ccii[i + 1]; j++) data[ng * i + cridx[j]] = cdata[j];
206   PetscCall(MatDenseRestoreArrayWrite(sGf[0], &data));
207 
208   PetscCall(PetscFree(cdata));
209   PetscCall(PetscFree(ccii));
210   PetscCall(PetscFree(cridx));
211   PetscCall(PCDestroy(&pcbddc));
212   PetscCall(MatDestroy(&A));
213   PetscFunctionReturn(PETSC_SUCCESS);
214 }
215 
PCMGGDSWCreateCoarseSpace_Private(PC pc,PetscInt l,DM dm,KSP smooth,PetscInt Nc,Mat guess,Mat * cspace)216 PetscErrorCode PCMGGDSWCreateCoarseSpace_Private(PC pc, PetscInt l, DM dm, KSP smooth, PetscInt Nc, Mat guess, Mat *cspace)
217 {
218   KSP            *sksp;
219   Mat             A, *sA_IG, *sGf, preallocator;
220   IS              Gidx, GidxMult, cG;
221   IS             *sI, *sG, *sGi, *sGiM;
222   const PetscInt *cidx;
223   PetscInt        NG, ns, n, i, c, rbs, cbs[2];
224   PetscBool       flg;
225   MatType         ptype;
226 
227   PetscFunctionBegin;
228   *cspace = NULL;
229   if (!l) PetscFunctionReturn(PETSC_SUCCESS);
230   if (pc->useAmat) {
231     PetscCall(KSPGetOperatorsSet(smooth, &flg, NULL));
232     PetscCheck(flg, PetscObjectComm((PetscObject)smooth), PETSC_ERR_ORDER, "Amat not set");
233     PetscCall(KSPGetOperators(smooth, &A, NULL));
234   } else {
235     PetscCall(KSPGetOperatorsSet(smooth, NULL, &flg));
236     PetscCheck(flg, PetscObjectComm((PetscObject)smooth), PETSC_ERR_ORDER, "Pmat not set");
237     PetscCall(KSPGetOperators(smooth, NULL, &A));
238   }
239 
240   /* Setup (also setup smoother here) */
241   if (!pc->setupcalled) PetscCall(KSPSetFromOptions(smooth));
242   PetscCall(KSPSetUp(smooth));
243   PetscCall(KSPSetUpOnBlocks(smooth));
244   PetscCall(PCMGGDSWSetUp(pc, l, dm, smooth, Nc, A, &ns, &sA_IG, &sksp, &sI, &sG, &sGf, &sGi, &sGiM));
245 
246   /* Number GDSW basis functions */
247   PetscCall(ISConcatenate(PetscObjectComm((PetscObject)A), ns, sGi, &Gidx));
248   PetscCall(ISConcatenate(PetscObjectComm((PetscObject)A), ns, sGiM, &GidxMult));
249   PetscCall(ISRenumber(Gidx, GidxMult, &NG, &cG));
250   PetscCall(ISDestroy(&Gidx));
251 
252   /* Detect column block size */
253   PetscCall(ISGetMinMax(GidxMult, &cbs[0], &cbs[1]));
254   PetscCall(PetscGlobalMinMaxInt(PetscObjectComm((PetscObject)A), cbs, cbs));
255   PetscCall(ISDestroy(&GidxMult));
256 
257   /* Construct global interpolation matrix */
258   PetscCall(MatGetLocalSize(A, NULL, &n));
259   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &preallocator));
260   PetscCall(MatSetSizes(preallocator, n, PETSC_DECIDE, PETSC_DECIDE, NG));
261   PetscCall(MatSetType(preallocator, MATPREALLOCATOR));
262   PetscCall(MatSetUp(preallocator));
263   PetscCall(ISGetIndices(cG, &cidx));
264   for (i = 0, c = 0; i < ns; i++) {
265     const PetscInt *ri, *rg;
266     PetscInt        nri, nrg, ncg;
267 
268     PetscCall(ISGetLocalSize(sI[i], &nri));
269     PetscCall(ISGetLocalSize(sG[i], &nrg));
270     PetscCall(ISGetIndices(sI[i], &ri));
271     PetscCall(ISGetIndices(sG[i], &rg));
272     PetscCall(MatGetSize(sGf[i], NULL, &ncg));
273     PetscCall(MatSetValues(preallocator, nri, ri, ncg, cidx + c, NULL, INSERT_VALUES));
274     PetscCall(MatSetValues(preallocator, nrg, rg, ncg, cidx + c, NULL, INSERT_VALUES));
275     PetscCall(ISRestoreIndices(sI[i], &ri));
276     PetscCall(ISRestoreIndices(sG[i], &rg));
277   }
278   PetscCall(MatAssemblyBegin(preallocator, MAT_FINAL_ASSEMBLY));
279   PetscCall(MatAssemblyEnd(preallocator, MAT_FINAL_ASSEMBLY));
280 
281   ptype = MATAIJ;
282   if (PetscDefined(HAVE_DEVICE)) {
283     PetscCall(MatBoundToCPU(A, &flg));
284     if (!flg) {
285       VecType vtype;
286       char   *found = NULL;
287 
288       PetscCall(MatGetVecType(A, &vtype));
289       PetscCall(PetscStrstr(vtype, "cuda", &found));
290       if (found) ptype = MATAIJCUSPARSE;
291     }
292   }
293   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), cspace));
294   PetscCall(MatSetSizes(*cspace, n, PETSC_DECIDE, PETSC_DECIDE, NG));
295   PetscCall(MatSetType(*cspace, ptype));
296   PetscCall(MatGetBlockSizes(A, NULL, &rbs));
297   PetscCall(MatSetBlockSizes(*cspace, rbs, cbs[0] == cbs[1] ? cbs[0] : 1));
298   PetscCall(MatPreallocatorPreallocate(preallocator, PETSC_FALSE, *cspace));
299   PetscCall(MatDestroy(&preallocator));
300   PetscCall(MatSetOption(*cspace, MAT_ROW_ORIENTED, PETSC_FALSE));
301 
302   for (i = 0, c = 0; i < ns; i++) {
303     Mat                X, Y;
304     const PetscScalar *v;
305     const PetscInt    *ri, *rg;
306     PetscInt           nri, nrg, ncg;
307 
308     PetscCall(MatMatMult(sA_IG[i], sGf[i], MAT_INITIAL_MATRIX, PETSC_CURRENT, &Y));
309     PetscCall(MatScale(Y, -1.0));
310     PetscCall(MatDuplicate(Y, MAT_DO_NOT_COPY_VALUES, &X));
311     PetscCall(KSPMatSolve(sksp[i], Y, X));
312 
313     PetscCall(ISGetLocalSize(sI[i], &nri));
314     PetscCall(ISGetLocalSize(sG[i], &nrg));
315     PetscCall(ISGetIndices(sI[i], &ri));
316     PetscCall(ISGetIndices(sG[i], &rg));
317     PetscCall(MatGetSize(sGf[i], NULL, &ncg));
318 
319     PetscCall(MatDenseGetArrayRead(X, &v));
320     PetscCall(MatSetValues(*cspace, nri, ri, ncg, cidx + c, v, INSERT_VALUES));
321     PetscCall(MatDenseRestoreArrayRead(X, &v));
322     PetscCall(MatDenseGetArrayRead(sGf[i], &v));
323     PetscCall(MatSetValues(*cspace, nrg, rg, ncg, cidx + c, v, INSERT_VALUES));
324     PetscCall(MatDenseRestoreArrayRead(sGf[i], &v));
325     PetscCall(ISRestoreIndices(sI[i], &ri));
326     PetscCall(ISRestoreIndices(sG[i], &rg));
327     PetscCall(MatDestroy(&Y));
328     PetscCall(MatDestroy(&X));
329   }
330   PetscCall(ISRestoreIndices(cG, &cidx));
331   PetscCall(ISDestroy(&cG));
332   PetscCall(MatAssemblyBegin(*cspace, MAT_FINAL_ASSEMBLY));
333   PetscCall(MatAssemblyEnd(*cspace, MAT_FINAL_ASSEMBLY));
334 
335   for (i = 0; i < ns; i++) {
336     PetscCall(KSPDestroy(&sksp[i]));
337     PetscCall(ISDestroy(&sI[i]));
338     PetscCall(ISDestroy(&sG[i]));
339     PetscCall(ISDestroy(&sGi[i]));
340     PetscCall(ISDestroy(&sGiM[i]));
341     PetscCall(MatDestroy(&sGf[i]));
342     PetscCall(MatDestroy(&sA_IG[i]));
343   }
344   PetscCall(PetscFree(sksp));
345   PetscCall(PetscFree(sI));
346   PetscCall(PetscFree(sG));
347   PetscCall(PetscFree(sGi));
348   PetscCall(PetscFree(sGiM));
349   PetscCall(PetscFree(sGf));
350   PetscCall(PetscFree(sA_IG));
351   PetscFunctionReturn(PETSC_SUCCESS);
352 }
353