1 /* 2 This file defines an "generalized" additive Schwarz preconditioner for any Mat implementation. 3 In this version each processor may intersect multiple subdomains and any subdomain may 4 intersect multiple processors. Intersections of subdomains with processors are called *local 5 subdomains*. 6 7 N - total number of distinct global subdomains (set explicitly in PCGASMSetTotalSubdomains() or implicitly PCGASMSetSubdomains() and then calculated in PCSetUp_GASM()) 8 n - actual number of local subdomains on this processor (set in PCGASMSetSubdomains() or calculated in PCGASMSetTotalSubdomains()) 9 nmax - maximum number of local subdomains per processor (calculated in PCSetUp_GASM()) 10 */ 11 #include <petsc/private/pcimpl.h> /*I "petscpc.h" I*/ 12 #include <petscdm.h> 13 14 typedef struct { 15 PetscInt N,n,nmax; 16 PetscInt overlap; /* overlap requested by user */ 17 PCGASMType type; /* use reduced interpolation, restriction or both */ 18 PetscBool type_set; /* if user set this value (so won't change it for symmetric problems) */ 19 PetscBool same_subdomain_solvers; /* flag indicating whether all local solvers are same */ 20 PetscBool sort_indices; /* flag to sort subdomain indices */ 21 PetscBool user_subdomains; /* whether the user set explicit subdomain index sets -- keep them on PCReset() */ 22 PetscBool dm_subdomains; /* whether DM is allowed to define subdomains */ 23 PetscBool hierarchicalpartitioning; 24 IS *ois; /* index sets that define the outer (conceptually, overlapping) subdomains */ 25 IS *iis; /* index sets that define the inner (conceptually, nonoverlapping) subdomains */ 26 KSP *ksp; /* linear solvers for each subdomain */ 27 Mat *pmat; /* subdomain block matrices */ 28 Vec gx,gy; /* Merged work vectors */ 29 Vec *x,*y; /* Split work vectors; storage aliases pieces of storage of the above merged vectors. */ 30 VecScatter gorestriction; /* merged restriction to disjoint union of outer subdomains */ 31 VecScatter girestriction; /* merged restriction to disjoint union of inner subdomains */ 32 VecScatter pctoouter; 33 IS permutationIS; 34 Mat permutationP; 35 Mat pcmat; 36 Vec pcx,pcy; 37 } PC_GASM; 38 39 static PetscErrorCode PCGASMComputeGlobalSubdomainNumbering_Private(PC pc,PetscInt **numbering,PetscInt **permutation) 40 { 41 PC_GASM *osm = (PC_GASM*)pc->data; 42 PetscInt i; 43 PetscErrorCode ierr; 44 45 PetscFunctionBegin; 46 /* Determine the number of globally-distinct subdomains and compute a global numbering for them. */ 47 ierr = PetscMalloc2(osm->n,numbering,osm->n,permutation);CHKERRQ(ierr); 48 ierr = PetscObjectsListGetGlobalNumbering(PetscObjectComm((PetscObject)pc),osm->n,(PetscObject*)osm->iis,NULL,*numbering);CHKERRQ(ierr); 49 for (i = 0; i < osm->n; ++i) (*permutation)[i] = i; 50 ierr = PetscSortIntWithPermutation(osm->n,*numbering,*permutation);CHKERRQ(ierr); 51 PetscFunctionReturn(0); 52 } 53 54 static PetscErrorCode PCGASMSubdomainView_Private(PC pc, PetscInt i, PetscViewer viewer) 55 { 56 PC_GASM *osm = (PC_GASM*)pc->data; 57 PetscInt j,nidx; 58 const PetscInt *idx; 59 PetscViewer sviewer; 60 char *cidx; 61 PetscErrorCode ierr; 62 63 PetscFunctionBegin; 64 if (i < 0 || i > osm->n) SETERRQ2(PetscObjectComm((PetscObject)viewer), PETSC_ERR_ARG_WRONG, "Invalid subdomain %D: must nonnegative and less than %D", i, osm->n); 65 /* Inner subdomains. */ 66 ierr = ISGetLocalSize(osm->iis[i], &nidx);CHKERRQ(ierr); 67 /* 68 No more than 15 characters per index plus a space. 69 PetscViewerStringSPrintf requires a string of size at least 2, so use (nidx+1) instead of nidx, 70 in case nidx == 0. That will take care of the space for the trailing '\0' as well. 71 For nidx == 0, the whole string 16 '\0'. 72 */ 73 ierr = PetscMalloc1(16*(nidx+1)+1, &cidx);CHKERRQ(ierr); 74 ierr = PetscViewerStringOpen(PETSC_COMM_SELF, cidx, 16*(nidx+1)+1, &sviewer);CHKERRQ(ierr); 75 ierr = ISGetIndices(osm->iis[i], &idx);CHKERRQ(ierr); 76 for (j = 0; j < nidx; ++j) { 77 ierr = PetscViewerStringSPrintf(sviewer, "%D ", idx[j]);CHKERRQ(ierr); 78 } 79 ierr = ISRestoreIndices(osm->iis[i],&idx);CHKERRQ(ierr); 80 ierr = PetscViewerDestroy(&sviewer);CHKERRQ(ierr); 81 ierr = PetscViewerASCIIPrintf(viewer, "Inner subdomain:\n");CHKERRQ(ierr); 82 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 83 ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr); 84 ierr = PetscViewerASCIISynchronizedPrintf(viewer, "%s", cidx);CHKERRQ(ierr); 85 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 86 ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr); 87 ierr = PetscViewerASCIIPrintf(viewer, "\n");CHKERRQ(ierr); 88 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 89 ierr = PetscFree(cidx);CHKERRQ(ierr); 90 /* Outer subdomains. */ 91 ierr = ISGetLocalSize(osm->ois[i], &nidx);CHKERRQ(ierr); 92 /* 93 No more than 15 characters per index plus a space. 94 PetscViewerStringSPrintf requires a string of size at least 2, so use (nidx+1) instead of nidx, 95 in case nidx == 0. That will take care of the space for the trailing '\0' as well. 96 For nidx == 0, the whole string 16 '\0'. 97 */ 98 ierr = PetscMalloc1(16*(nidx+1)+1, &cidx);CHKERRQ(ierr); 99 ierr = PetscViewerStringOpen(PETSC_COMM_SELF, cidx, 16*(nidx+1)+1, &sviewer);CHKERRQ(ierr); 100 ierr = ISGetIndices(osm->ois[i], &idx);CHKERRQ(ierr); 101 for (j = 0; j < nidx; ++j) { 102 ierr = PetscViewerStringSPrintf(sviewer,"%D ", idx[j]);CHKERRQ(ierr); 103 } 104 ierr = PetscViewerDestroy(&sviewer);CHKERRQ(ierr); 105 ierr = ISRestoreIndices(osm->ois[i],&idx);CHKERRQ(ierr); 106 ierr = PetscViewerASCIIPrintf(viewer, "Outer subdomain:\n");CHKERRQ(ierr); 107 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 108 ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr); 109 ierr = PetscViewerASCIISynchronizedPrintf(viewer, "%s", cidx);CHKERRQ(ierr); 110 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 111 ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr); 112 ierr = PetscViewerASCIIPrintf(viewer, "\n");CHKERRQ(ierr); 113 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 114 ierr = PetscFree(cidx);CHKERRQ(ierr); 115 PetscFunctionReturn(0); 116 } 117 118 static PetscErrorCode PCGASMPrintSubdomains(PC pc) 119 { 120 PC_GASM *osm = (PC_GASM*)pc->data; 121 const char *prefix; 122 char fname[PETSC_MAX_PATH_LEN+1]; 123 PetscInt l, d, count; 124 PetscBool doprint,found; 125 PetscViewer viewer, sviewer = NULL; 126 PetscInt *numbering,*permutation;/* global numbering of locally-supported subdomains and the permutation from the local ordering */ 127 PetscErrorCode ierr; 128 129 PetscFunctionBegin; 130 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 131 doprint = PETSC_FALSE; 132 ierr = PetscOptionsGetBool(NULL,prefix,"-pc_gasm_print_subdomains",&doprint,NULL);CHKERRQ(ierr); 133 if (!doprint) PetscFunctionReturn(0); 134 ierr = PetscOptionsGetString(NULL,prefix,"-pc_gasm_print_subdomains",fname,PETSC_MAX_PATH_LEN,&found);CHKERRQ(ierr); 135 if (!found) { ierr = PetscStrcpy(fname,"stdout");CHKERRQ(ierr); }; 136 ierr = PetscViewerASCIIOpen(PetscObjectComm((PetscObject)pc),fname,&viewer);CHKERRQ(ierr); 137 /* 138 Make sure the viewer has a name. Otherwise this may cause a deadlock or other weird errors when creating a subcomm viewer: 139 the subcomm viewer will attempt to inherit the viewer's name, which, if not set, will be constructed collectively on the comm. 140 */ 141 ierr = PetscObjectName((PetscObject)viewer);CHKERRQ(ierr); 142 l = 0; 143 ierr = PCGASMComputeGlobalSubdomainNumbering_Private(pc,&numbering,&permutation);CHKERRQ(ierr); 144 for (count = 0; count < osm->N; ++count) { 145 /* Now let subdomains go one at a time in the global numbering order and print their subdomain/solver info. */ 146 if (l<osm->n) { 147 d = permutation[l]; /* d is the local number of the l-th smallest (in the global ordering) among the locally supported subdomains */ 148 if (numbering[d] == count) { 149 ierr = PetscViewerGetSubViewer(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 150 ierr = PCGASMSubdomainView_Private(pc,d,sviewer);CHKERRQ(ierr); 151 ierr = PetscViewerRestoreSubViewer(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 152 ++l; 153 } 154 } 155 ierr = MPI_Barrier(PetscObjectComm((PetscObject)pc));CHKERRQ(ierr); 156 } 157 ierr = PetscFree2(numbering,permutation);CHKERRQ(ierr); 158 ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); 159 PetscFunctionReturn(0); 160 } 161 162 163 static PetscErrorCode PCView_GASM(PC pc,PetscViewer viewer) 164 { 165 PC_GASM *osm = (PC_GASM*)pc->data; 166 const char *prefix; 167 PetscErrorCode ierr; 168 PetscMPIInt rank, size; 169 PetscInt bsz; 170 PetscBool iascii,view_subdomains=PETSC_FALSE; 171 PetscViewer sviewer; 172 PetscInt count, l; 173 char overlap[256] = "user-defined overlap"; 174 char gsubdomains[256] = "unknown total number of subdomains"; 175 char msubdomains[256] = "unknown max number of local subdomains"; 176 PetscInt *numbering,*permutation;/* global numbering of locally-supported subdomains and the permutation from the local ordering */ 177 178 PetscFunctionBegin; 179 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)pc), &size);CHKERRQ(ierr); 180 ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)pc), &rank);CHKERRQ(ierr); 181 182 if (osm->overlap >= 0) { 183 ierr = PetscSNPrintf(overlap,sizeof(overlap),"requested amount of overlap = %D",osm->overlap);CHKERRQ(ierr); 184 } 185 if (osm->N != PETSC_DETERMINE) { 186 ierr = PetscSNPrintf(gsubdomains, sizeof(gsubdomains), "total number of subdomains = %D",osm->N);CHKERRQ(ierr); 187 } 188 if (osm->nmax != PETSC_DETERMINE) { 189 ierr = PetscSNPrintf(msubdomains,sizeof(msubdomains),"max number of local subdomains = %D",osm->nmax);CHKERRQ(ierr); 190 } 191 192 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 193 ierr = PetscOptionsGetBool(NULL,prefix,"-pc_gasm_view_subdomains",&view_subdomains,NULL);CHKERRQ(ierr); 194 195 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 196 if (iascii) { 197 /* 198 Make sure the viewer has a name. Otherwise this may cause a deadlock when creating a subcomm viewer: 199 the subcomm viewer will attempt to inherit the viewer's name, which, if not set, will be constructed 200 collectively on the comm. 201 */ 202 ierr = PetscObjectName((PetscObject)viewer);CHKERRQ(ierr); 203 ierr = PetscViewerASCIIPrintf(viewer," Restriction/interpolation type: %s\n",PCGASMTypes[osm->type]);CHKERRQ(ierr); 204 ierr = PetscViewerASCIIPrintf(viewer," %s\n",overlap);CHKERRQ(ierr); 205 ierr = PetscViewerASCIIPrintf(viewer," %s\n",gsubdomains);CHKERRQ(ierr); 206 ierr = PetscViewerASCIIPrintf(viewer," %s\n",msubdomains);CHKERRQ(ierr); 207 ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr); 208 ierr = PetscViewerASCIISynchronizedPrintf(viewer," [%d|%d] number of locally-supported subdomains = %D\n",rank,size,osm->n);CHKERRQ(ierr); 209 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 210 ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr); 211 /* Cannot take advantage of osm->same_subdomain_solvers without a global numbering of subdomains. */ 212 ierr = PetscViewerASCIIPrintf(viewer," Subdomain solver info is as follows:\n");CHKERRQ(ierr); 213 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 214 ierr = PetscViewerASCIIPrintf(viewer," - - - - - - - - - - - - - - - - - -\n");CHKERRQ(ierr); 215 /* Make sure that everybody waits for the banner to be printed. */ 216 ierr = MPI_Barrier(PetscObjectComm((PetscObject)viewer));CHKERRQ(ierr); 217 /* Now let subdomains go one at a time in the global numbering order and print their subdomain/solver info. */ 218 ierr = PCGASMComputeGlobalSubdomainNumbering_Private(pc,&numbering,&permutation);CHKERRQ(ierr); 219 l = 0; 220 for (count = 0; count < osm->N; ++count) { 221 PetscMPIInt srank, ssize; 222 if (l<osm->n) { 223 PetscInt d = permutation[l]; /* d is the local number of the l-th smallest (in the global ordering) among the locally supported subdomains */ 224 if (numbering[d] == count) { 225 ierr = MPI_Comm_size(((PetscObject)osm->ois[d])->comm, &ssize);CHKERRQ(ierr); 226 ierr = MPI_Comm_rank(((PetscObject)osm->ois[d])->comm, &srank);CHKERRQ(ierr); 227 ierr = PetscViewerGetSubViewer(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 228 ierr = ISGetLocalSize(osm->ois[d],&bsz);CHKERRQ(ierr); 229 ierr = PetscViewerASCIISynchronizedPrintf(sviewer," [%d|%d] (subcomm [%d|%d]) local subdomain number %D, local size = %D\n",rank,size,srank,ssize,d,bsz);CHKERRQ(ierr); 230 ierr = PetscViewerFlush(sviewer);CHKERRQ(ierr); 231 if (view_subdomains) { 232 ierr = PCGASMSubdomainView_Private(pc,d,sviewer);CHKERRQ(ierr); 233 } 234 if (!pc->setupcalled) { 235 ierr = PetscViewerASCIIPrintf(sviewer, " Solver not set up yet: PCSetUp() not yet called\n");CHKERRQ(ierr); 236 } else { 237 ierr = KSPView(osm->ksp[d],sviewer);CHKERRQ(ierr); 238 } 239 ierr = PetscViewerASCIIPrintf(sviewer," - - - - - - - - - - - - - - - - - -\n");CHKERRQ(ierr); 240 ierr = PetscViewerFlush(sviewer);CHKERRQ(ierr); 241 ierr = PetscViewerRestoreSubViewer(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 242 ++l; 243 } 244 } 245 ierr = MPI_Barrier(PetscObjectComm((PetscObject)pc));CHKERRQ(ierr); 246 } 247 ierr = PetscFree2(numbering,permutation);CHKERRQ(ierr); 248 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 249 } 250 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 251 ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr); 252 PetscFunctionReturn(0); 253 } 254 255 PETSC_INTERN PetscErrorCode PCGASMCreateLocalSubdomains(Mat A, PetscInt nloc, IS *iis[]); 256 257 258 259 PetscErrorCode PCGASMSetHierarchicalPartitioning(PC pc) 260 { 261 PC_GASM *osm = (PC_GASM*)pc->data; 262 MatPartitioning part; 263 MPI_Comm comm; 264 PetscMPIInt size; 265 PetscInt nlocalsubdomains,fromrows_localsize; 266 IS partitioning,fromrows,isn; 267 Vec outervec; 268 PetscErrorCode ierr; 269 270 PetscFunctionBegin; 271 ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr); 272 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 273 /* we do not need a hierarchical partitioning when 274 * the total number of subdomains is consistent with 275 * the number of MPI tasks. 276 * For the following cases, we do not need to use HP 277 * */ 278 if(osm->N==PETSC_DETERMINE || osm->N>=size || osm->N==1) PetscFunctionReturn(0); 279 if(size%osm->N != 0) SETERRQ2(PETSC_COMM_WORLD,PETSC_ERR_ARG_INCOMP,"have to specify the total number of subdomains %D to be a factor of the number of processors %d \n",osm->N,size); 280 nlocalsubdomains = size/osm->N; 281 osm->n = 1; 282 ierr = MatPartitioningCreate(comm,&part);CHKERRQ(ierr); 283 ierr = MatPartitioningSetAdjacency(part,pc->pmat);CHKERRQ(ierr); 284 ierr = MatPartitioningSetType(part,MATPARTITIONINGHIERARCH);CHKERRQ(ierr); 285 ierr = MatPartitioningHierarchicalSetNcoarseparts(part,osm->N);CHKERRQ(ierr); 286 ierr = MatPartitioningHierarchicalSetNfineparts(part,nlocalsubdomains);CHKERRQ(ierr); 287 ierr = MatPartitioningSetFromOptions(part);CHKERRQ(ierr); 288 /* get new processor owner number of each vertex */ 289 ierr = MatPartitioningApply(part,&partitioning);CHKERRQ(ierr); 290 ierr = ISBuildTwoSided(partitioning,NULL,&fromrows);CHKERRQ(ierr); 291 ierr = ISPartitioningToNumbering(partitioning,&isn);CHKERRQ(ierr); 292 ierr = ISDestroy(&isn);CHKERRQ(ierr); 293 ierr = ISGetLocalSize(fromrows,&fromrows_localsize);CHKERRQ(ierr); 294 ierr = MatPartitioningDestroy(&part);CHKERRQ(ierr); 295 ierr = MatCreateVecs(pc->pmat,&outervec,NULL);CHKERRQ(ierr); 296 ierr = VecCreateMPI(comm,fromrows_localsize,PETSC_DETERMINE,&(osm->pcx));CHKERRQ(ierr); 297 ierr = VecDuplicate(osm->pcx,&(osm->pcy));CHKERRQ(ierr); 298 ierr = VecScatterCreate(osm->pcx,NULL,outervec,fromrows,&(osm->pctoouter));CHKERRQ(ierr); 299 ierr = MatCreateSubMatrix(pc->pmat,fromrows,fromrows,MAT_INITIAL_MATRIX,&(osm->permutationP));CHKERRQ(ierr); 300 ierr = PetscObjectReference((PetscObject)fromrows);CHKERRQ(ierr); 301 osm->permutationIS = fromrows; 302 osm->pcmat = pc->pmat; 303 ierr = PetscObjectReference((PetscObject)osm->permutationP);CHKERRQ(ierr); 304 pc->pmat = osm->permutationP; 305 ierr = VecDestroy(&outervec);CHKERRQ(ierr); 306 ierr = ISDestroy(&fromrows);CHKERRQ(ierr); 307 ierr = ISDestroy(&partitioning);CHKERRQ(ierr); 308 osm->n = PETSC_DETERMINE; 309 PetscFunctionReturn(0); 310 } 311 312 313 314 static PetscErrorCode PCSetUp_GASM(PC pc) 315 { 316 PC_GASM *osm = (PC_GASM*)pc->data; 317 PetscErrorCode ierr; 318 PetscBool symset,flg; 319 PetscInt i,nInnerIndices,nTotalInnerIndices; 320 PetscMPIInt rank, size; 321 MatReuse scall = MAT_REUSE_MATRIX; 322 KSP ksp; 323 PC subpc; 324 const char *prefix,*pprefix; 325 Vec x,y; 326 PetscInt oni; /* Number of indices in the i-th local outer subdomain. */ 327 const PetscInt *oidxi; /* Indices from the i-th subdomain local outer subdomain. */ 328 PetscInt on; /* Number of indices in the disjoint union of local outer subdomains. */ 329 PetscInt *oidx; /* Indices in the disjoint union of local outer subdomains. */ 330 IS gois; /* Disjoint union the global indices of outer subdomains. */ 331 IS goid; /* Identity IS of the size of the disjoint union of outer subdomains. */ 332 PetscScalar *gxarray, *gyarray; 333 PetscInt gostart; /* Start of locally-owned indices in the vectors -- osm->gx,osm->gy -- over the disjoint union of outer subdomains. */ 334 PetscInt num_subdomains = 0; 335 DM *subdomain_dm = NULL; 336 char **subdomain_names = NULL; 337 PetscInt *numbering; 338 339 340 PetscFunctionBegin; 341 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);CHKERRQ(ierr); 342 ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)pc),&rank);CHKERRQ(ierr); 343 if (!pc->setupcalled) { 344 /* use a hierarchical partitioning */ 345 if(osm->hierarchicalpartitioning){ 346 ierr = PCGASMSetHierarchicalPartitioning(pc);CHKERRQ(ierr); 347 } 348 if (!osm->type_set) { 349 ierr = MatIsSymmetricKnown(pc->pmat,&symset,&flg);CHKERRQ(ierr); 350 if (symset && flg) osm->type = PC_GASM_BASIC; 351 } 352 353 if (osm->n == PETSC_DETERMINE) { 354 if (osm->N != PETSC_DETERMINE) { 355 /* No local subdomains given, but the desired number of total subdomains is known, so construct them accordingly. */ 356 ierr = PCGASMCreateSubdomains(pc->pmat,osm->N,&osm->n,&osm->iis);CHKERRQ(ierr); 357 } else if (osm->dm_subdomains && pc->dm) { 358 /* try pc->dm next, if allowed */ 359 PetscInt d; 360 IS *inner_subdomain_is, *outer_subdomain_is; 361 ierr = DMCreateDomainDecomposition(pc->dm, &num_subdomains, &subdomain_names, &inner_subdomain_is, &outer_subdomain_is, &subdomain_dm);CHKERRQ(ierr); 362 if (num_subdomains) { 363 ierr = PCGASMSetSubdomains(pc, num_subdomains, inner_subdomain_is, outer_subdomain_is);CHKERRQ(ierr); 364 } 365 for (d = 0; d < num_subdomains; ++d) { 366 if (inner_subdomain_is) {ierr = ISDestroy(&inner_subdomain_is[d]);CHKERRQ(ierr);} 367 if (outer_subdomain_is) {ierr = ISDestroy(&outer_subdomain_is[d]);CHKERRQ(ierr);} 368 } 369 ierr = PetscFree(inner_subdomain_is);CHKERRQ(ierr); 370 ierr = PetscFree(outer_subdomain_is);CHKERRQ(ierr); 371 } else { 372 /* still no subdomains; use one per processor */ 373 osm->nmax = osm->n = 1; 374 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);CHKERRQ(ierr); 375 osm->N = size; 376 ierr = PCGASMCreateLocalSubdomains(pc->pmat,osm->n,&osm->iis);CHKERRQ(ierr); 377 } 378 } 379 if (!osm->iis) { 380 /* 381 osm->n was set in PCGASMSetSubdomains(), but the actual subdomains have not been supplied. 382 We create the requisite number of local inner subdomains and then expand them into 383 out subdomains, if necessary. 384 */ 385 ierr = PCGASMCreateLocalSubdomains(pc->pmat,osm->n,&osm->iis);CHKERRQ(ierr); 386 } 387 if (!osm->ois) { 388 /* 389 Initially make outer subdomains the same as inner subdomains. If nonzero additional overlap 390 has been requested, copy the inner subdomains over so they can be modified. 391 */ 392 ierr = PetscMalloc1(osm->n,&osm->ois);CHKERRQ(ierr); 393 for (i=0; i<osm->n; ++i) { 394 if (osm->overlap > 0 && osm->N>1) { /* With positive overlap, osm->iis[i] will be modified */ 395 ierr = ISDuplicate(osm->iis[i],(osm->ois)+i);CHKERRQ(ierr); 396 ierr = ISCopy(osm->iis[i],osm->ois[i]);CHKERRQ(ierr); 397 } else { 398 ierr = PetscObjectReference((PetscObject)((osm->iis)[i]));CHKERRQ(ierr); 399 osm->ois[i] = osm->iis[i]; 400 } 401 } 402 if (osm->overlap>0 && osm->N>1) { 403 /* Extend the "overlapping" regions by a number of steps */ 404 ierr = MatIncreaseOverlapSplit(pc->pmat,osm->n,osm->ois,osm->overlap);CHKERRQ(ierr); 405 } 406 } 407 408 /* Now the subdomains are defined. Determine their global and max local numbers, if necessary. */ 409 if (osm->nmax == PETSC_DETERMINE) { 410 PetscMPIInt inwork,outwork; 411 /* determine global number of subdomains and the max number of local subdomains */ 412 inwork = osm->n; 413 ierr = MPIU_Allreduce(&inwork,&outwork,1,MPI_INT,MPI_MAX,PetscObjectComm((PetscObject)pc));CHKERRQ(ierr); 414 osm->nmax = outwork; 415 } 416 if (osm->N == PETSC_DETERMINE) { 417 /* Determine the number of globally-distinct subdomains and compute a global numbering for them. */ 418 ierr = PetscObjectsListGetGlobalNumbering(PetscObjectComm((PetscObject)pc),osm->n,(PetscObject*)osm->ois,&osm->N,NULL);CHKERRQ(ierr); 419 } 420 421 422 if (osm->sort_indices) { 423 for (i=0; i<osm->n; i++) { 424 ierr = ISSort(osm->ois[i]);CHKERRQ(ierr); 425 ierr = ISSort(osm->iis[i]);CHKERRQ(ierr); 426 } 427 } 428 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 429 ierr = PCGASMPrintSubdomains(pc);CHKERRQ(ierr); 430 431 /* 432 Merge the ISs, create merged vectors and restrictions. 433 */ 434 /* Merge outer subdomain ISs and construct a restriction onto the disjoint union of local outer subdomains. */ 435 on = 0; 436 for (i=0; i<osm->n; i++) { 437 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 438 on += oni; 439 } 440 ierr = PetscMalloc1(on, &oidx);CHKERRQ(ierr); 441 on = 0; 442 /* Merge local indices together */ 443 for (i=0; i<osm->n; i++) { 444 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 445 ierr = ISGetIndices(osm->ois[i],&oidxi);CHKERRQ(ierr); 446 ierr = PetscMemcpy(oidx+on,oidxi,sizeof(PetscInt)*oni);CHKERRQ(ierr); 447 ierr = ISRestoreIndices(osm->ois[i],&oidxi);CHKERRQ(ierr); 448 on += oni; 449 } 450 ierr = ISCreateGeneral(((PetscObject)(pc))->comm,on,oidx,PETSC_OWN_POINTER,&gois);CHKERRQ(ierr); 451 nTotalInnerIndices = 0; 452 for(i=0; i<osm->n; i++){ 453 ierr = ISGetLocalSize(osm->iis[i],&nInnerIndices);CHKERRQ(ierr); 454 nTotalInnerIndices += nInnerIndices; 455 } 456 ierr = VecCreateMPI(((PetscObject)(pc))->comm,nTotalInnerIndices,PETSC_DETERMINE,&x);CHKERRQ(ierr); 457 ierr = VecDuplicate(x,&y);CHKERRQ(ierr); 458 459 ierr = VecCreateMPI(PetscObjectComm((PetscObject)pc),on,PETSC_DECIDE,&osm->gx);CHKERRQ(ierr); 460 ierr = VecDuplicate(osm->gx,&osm->gy);CHKERRQ(ierr); 461 ierr = VecGetOwnershipRange(osm->gx, &gostart, NULL);CHKERRQ(ierr); 462 ierr = ISCreateStride(PetscObjectComm((PetscObject)pc),on,gostart,1, &goid);CHKERRQ(ierr); 463 /* gois might indices not on local */ 464 ierr = VecScatterCreate(x,gois,osm->gx,goid, &(osm->gorestriction));CHKERRQ(ierr); 465 ierr = PetscMalloc1(osm->n,&numbering);CHKERRQ(ierr); 466 ierr = PetscObjectsListGetGlobalNumbering(PetscObjectComm((PetscObject)pc),osm->n,(PetscObject*)osm->ois,NULL,numbering);CHKERRQ(ierr); 467 ierr = VecDestroy(&x);CHKERRQ(ierr); 468 ierr = ISDestroy(&gois);CHKERRQ(ierr); 469 470 /* Merge inner subdomain ISs and construct a restriction onto the disjoint union of local inner subdomains. */ 471 { 472 PetscInt ini; /* Number of indices the i-th a local inner subdomain. */ 473 PetscInt in; /* Number of indices in the disjoint uniont of local inner subdomains. */ 474 PetscInt *iidx; /* Global indices in the merged local inner subdomain. */ 475 PetscInt *ioidx; /* Global indices of the disjoint union of inner subdomains within the disjoint union of outer subdomains. */ 476 IS giis; /* IS for the disjoint union of inner subdomains. */ 477 IS giois; /* IS for the disjoint union of inner subdomains within the disjoint union of outer subdomains. */ 478 PetscScalar *array; 479 const PetscInt *indices; 480 PetscInt k; 481 on = 0; 482 for (i=0; i<osm->n; i++) { 483 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 484 on += oni; 485 } 486 ierr = PetscMalloc1(on, &iidx);CHKERRQ(ierr); 487 ierr = PetscMalloc1(on, &ioidx);CHKERRQ(ierr); 488 ierr = VecGetArray(y,&array);CHKERRQ(ierr); 489 /* set communicator id to determine where overlap is */ 490 in = 0; 491 for (i=0; i<osm->n; i++) { 492 ierr = ISGetLocalSize(osm->iis[i],&ini);CHKERRQ(ierr); 493 for (k = 0; k < ini; ++k){ 494 array[in+k] = numbering[i]; 495 } 496 in += ini; 497 } 498 ierr = VecRestoreArray(y,&array);CHKERRQ(ierr); 499 ierr = VecScatterBegin(osm->gorestriction,y,osm->gy,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 500 ierr = VecScatterEnd(osm->gorestriction,y,osm->gy,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 501 ierr = VecGetOwnershipRange(osm->gy,&gostart, NULL);CHKERRQ(ierr); 502 ierr = VecGetArray(osm->gy,&array);CHKERRQ(ierr); 503 on = 0; 504 in = 0; 505 for (i=0; i<osm->n; i++) { 506 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 507 ierr = ISGetIndices(osm->ois[i],&indices);CHKERRQ(ierr); 508 for (k=0; k<oni; k++) { 509 /* skip overlapping indices to get inner domain */ 510 if(PetscRealPart(array[on+k]) != numbering[i]) continue; 511 iidx[in] = indices[k]; 512 ioidx[in++] = gostart+on+k; 513 } 514 ierr = ISRestoreIndices(osm->ois[i], &indices);CHKERRQ(ierr); 515 on += oni; 516 } 517 ierr = VecRestoreArray(osm->gy,&array);CHKERRQ(ierr); 518 ierr = ISCreateGeneral(PetscObjectComm((PetscObject)pc),in,iidx,PETSC_OWN_POINTER,&giis);CHKERRQ(ierr); 519 ierr = ISCreateGeneral(PetscObjectComm((PetscObject)pc),in,ioidx,PETSC_OWN_POINTER,&giois);CHKERRQ(ierr); 520 ierr = VecScatterCreate(y,giis,osm->gy,giois,&osm->girestriction);CHKERRQ(ierr); 521 ierr = VecDestroy(&y);CHKERRQ(ierr); 522 ierr = ISDestroy(&giis);CHKERRQ(ierr); 523 ierr = ISDestroy(&giois);CHKERRQ(ierr); 524 } 525 ierr = ISDestroy(&goid);CHKERRQ(ierr); 526 ierr = PetscFree(numbering);CHKERRQ(ierr); 527 528 /* Create the subdomain work vectors. */ 529 ierr = PetscMalloc1(osm->n,&osm->x);CHKERRQ(ierr); 530 ierr = PetscMalloc1(osm->n,&osm->y);CHKERRQ(ierr); 531 ierr = VecGetArray(osm->gx, &gxarray);CHKERRQ(ierr); 532 ierr = VecGetArray(osm->gy, &gyarray);CHKERRQ(ierr); 533 for (i=0, on=0; i<osm->n; ++i, on += oni) { 534 PetscInt oNi; 535 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 536 /* on a sub communicator */ 537 ierr = ISGetSize(osm->ois[i],&oNi);CHKERRQ(ierr); 538 ierr = VecCreateMPIWithArray(((PetscObject)(osm->ois[i]))->comm,1,oni,oNi,gxarray+on,&osm->x[i]);CHKERRQ(ierr); 539 ierr = VecCreateMPIWithArray(((PetscObject)(osm->ois[i]))->comm,1,oni,oNi,gyarray+on,&osm->y[i]);CHKERRQ(ierr); 540 } 541 ierr = VecRestoreArray(osm->gx, &gxarray);CHKERRQ(ierr); 542 ierr = VecRestoreArray(osm->gy, &gyarray);CHKERRQ(ierr); 543 /* Create the subdomain solvers */ 544 ierr = PetscMalloc1(osm->n,&osm->ksp);CHKERRQ(ierr); 545 for (i=0; i<osm->n; i++) { 546 char subprefix[PETSC_MAX_PATH_LEN+1]; 547 ierr = KSPCreate(((PetscObject)(osm->ois[i]))->comm,&ksp);CHKERRQ(ierr); 548 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ksp);CHKERRQ(ierr); 549 ierr = PetscObjectIncrementTabLevel((PetscObject)ksp,(PetscObject)pc,1);CHKERRQ(ierr); 550 ierr = KSPSetType(ksp,KSPPREONLY);CHKERRQ(ierr); 551 ierr = KSPGetPC(ksp,&subpc);CHKERRQ(ierr); /* Why do we need this here? */ 552 if (subdomain_dm) { 553 ierr = KSPSetDM(ksp,subdomain_dm[i]);CHKERRQ(ierr); 554 ierr = DMDestroy(subdomain_dm+i);CHKERRQ(ierr); 555 } 556 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 557 ierr = KSPSetOptionsPrefix(ksp,prefix);CHKERRQ(ierr); 558 if (subdomain_names && subdomain_names[i]) { 559 ierr = PetscSNPrintf(subprefix,PETSC_MAX_PATH_LEN,"sub_%s_",subdomain_names[i]);CHKERRQ(ierr); 560 ierr = KSPAppendOptionsPrefix(ksp,subprefix);CHKERRQ(ierr); 561 ierr = PetscFree(subdomain_names[i]);CHKERRQ(ierr); 562 } 563 ierr = KSPAppendOptionsPrefix(ksp,"sub_");CHKERRQ(ierr); 564 osm->ksp[i] = ksp; 565 } 566 ierr = PetscFree(subdomain_dm);CHKERRQ(ierr); 567 ierr = PetscFree(subdomain_names);CHKERRQ(ierr); 568 scall = MAT_INITIAL_MATRIX; 569 570 } else { /* if (pc->setupcalled) */ 571 /* 572 Destroy the submatrices from the previous iteration 573 */ 574 if (pc->flag == DIFFERENT_NONZERO_PATTERN) { 575 ierr = MatDestroyMatrices(osm->n,&osm->pmat);CHKERRQ(ierr); 576 scall = MAT_INITIAL_MATRIX; 577 } 578 if(osm->permutationIS){ 579 ierr = MatCreateSubMatrix(pc->pmat,osm->permutationIS,osm->permutationIS,scall,&osm->permutationP);CHKERRQ(ierr); 580 ierr = PetscObjectReference((PetscObject)osm->permutationP);CHKERRQ(ierr); 581 osm->pcmat = pc->pmat; 582 pc->pmat = osm->permutationP; 583 } 584 585 } 586 587 588 /* 589 Extract out the submatrices. 590 */ 591 if (size > 1) { 592 ierr = MatCreateSubMatricesMPI(pc->pmat,osm->n,osm->ois,osm->ois,scall,&osm->pmat);CHKERRQ(ierr); 593 } else { 594 ierr = MatCreateSubMatrices(pc->pmat,osm->n,osm->ois,osm->ois,scall,&osm->pmat);CHKERRQ(ierr); 595 } 596 if (scall == MAT_INITIAL_MATRIX) { 597 ierr = PetscObjectGetOptionsPrefix((PetscObject)pc->pmat,&pprefix);CHKERRQ(ierr); 598 for (i=0; i<osm->n; i++) { 599 ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)osm->pmat[i]);CHKERRQ(ierr); 600 ierr = PetscObjectSetOptionsPrefix((PetscObject)osm->pmat[i],pprefix);CHKERRQ(ierr); 601 } 602 } 603 604 /* Return control to the user so that the submatrices can be modified (e.g., to apply 605 different boundary conditions for the submatrices than for the global problem) */ 606 ierr = PCModifySubMatrices(pc,osm->n,osm->ois,osm->ois,osm->pmat,pc->modifysubmatricesP);CHKERRQ(ierr); 607 608 /* 609 Loop over submatrices putting them into local ksps 610 */ 611 for (i=0; i<osm->n; i++) { 612 ierr = KSPSetOperators(osm->ksp[i],osm->pmat[i],osm->pmat[i]);CHKERRQ(ierr); 613 if (!pc->setupcalled) { 614 ierr = KSPSetFromOptions(osm->ksp[i]);CHKERRQ(ierr); 615 } 616 } 617 if(osm->pcmat){ 618 ierr = MatDestroy(&pc->pmat);CHKERRQ(ierr); 619 pc->pmat = osm->pcmat; 620 osm->pcmat = 0; 621 } 622 PetscFunctionReturn(0); 623 } 624 625 static PetscErrorCode PCSetUpOnBlocks_GASM(PC pc) 626 { 627 PC_GASM *osm = (PC_GASM*)pc->data; 628 PetscErrorCode ierr; 629 PetscInt i; 630 631 PetscFunctionBegin; 632 for (i=0; i<osm->n; i++) { 633 ierr = KSPSetUp(osm->ksp[i]);CHKERRQ(ierr); 634 } 635 PetscFunctionReturn(0); 636 } 637 638 static PetscErrorCode PCApply_GASM(PC pc,Vec xin,Vec yout) 639 { 640 PC_GASM *osm = (PC_GASM*)pc->data; 641 PetscErrorCode ierr; 642 PetscInt i; 643 Vec x,y; 644 ScatterMode forward = SCATTER_FORWARD,reverse = SCATTER_REVERSE; 645 646 PetscFunctionBegin; 647 if(osm->pctoouter){ 648 ierr = VecScatterBegin(osm->pctoouter,xin,osm->pcx,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 649 ierr = VecScatterEnd(osm->pctoouter,xin,osm->pcx,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 650 x = osm->pcx; 651 y = osm->pcy; 652 }else{ 653 x = xin; 654 y = yout; 655 } 656 /* 657 Support for limiting the restriction or interpolation only to the inner 658 subdomain values (leaving the other values 0). 659 */ 660 if (!(osm->type & PC_GASM_RESTRICT)) { 661 /* have to zero the work RHS since scatter may leave some slots empty */ 662 ierr = VecZeroEntries(osm->gx);CHKERRQ(ierr); 663 ierr = VecScatterBegin(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 664 } else { 665 ierr = VecScatterBegin(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 666 } 667 ierr = VecZeroEntries(osm->gy);CHKERRQ(ierr); 668 if (!(osm->type & PC_GASM_RESTRICT)) { 669 ierr = VecScatterEnd(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 670 } else { 671 ierr = VecScatterEnd(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 672 } 673 /* do the subdomain solves */ 674 for (i=0; i<osm->n; ++i) { 675 ierr = KSPSolve(osm->ksp[i],osm->x[i],osm->y[i]);CHKERRQ(ierr); 676 } 677 /* Do we need to zero y ?? */ 678 ierr = VecZeroEntries(y);CHKERRQ(ierr); 679 if (!(osm->type & PC_GASM_INTERPOLATE)) { 680 ierr = VecScatterBegin(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 681 ierr = VecScatterEnd(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 682 } else { 683 ierr = VecScatterBegin(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 684 ierr = VecScatterEnd(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 685 } 686 if(osm->pctoouter){ 687 ierr = VecScatterBegin(osm->pctoouter,y,yout,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 688 ierr = VecScatterEnd(osm->pctoouter,y,yout,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 689 } 690 PetscFunctionReturn(0); 691 } 692 693 static PetscErrorCode PCApplyTranspose_GASM(PC pc,Vec xin,Vec yout) 694 { 695 PC_GASM *osm = (PC_GASM*)pc->data; 696 PetscErrorCode ierr; 697 PetscInt i; 698 Vec x,y; 699 ScatterMode forward = SCATTER_FORWARD,reverse = SCATTER_REVERSE; 700 701 PetscFunctionBegin; 702 if(osm->pctoouter){ 703 ierr = VecScatterBegin(osm->pctoouter,xin,osm->pcx,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 704 ierr = VecScatterEnd(osm->pctoouter,xin,osm->pcx,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 705 x = osm->pcx; 706 y = osm->pcy; 707 }else{ 708 x = xin; 709 y = yout; 710 } 711 /* 712 Support for limiting the restriction or interpolation to only local 713 subdomain values (leaving the other values 0). 714 715 Note: these are reversed from the PCApply_GASM() because we are applying the 716 transpose of the three terms 717 */ 718 if (!(osm->type & PC_GASM_INTERPOLATE)) { 719 /* have to zero the work RHS since scatter may leave some slots empty */ 720 ierr = VecZeroEntries(osm->gx);CHKERRQ(ierr); 721 ierr = VecScatterBegin(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 722 } else { 723 ierr = VecScatterBegin(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 724 } 725 ierr = VecZeroEntries(osm->gy);CHKERRQ(ierr); 726 if (!(osm->type & PC_GASM_INTERPOLATE)) { 727 ierr = VecScatterEnd(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 728 } else { 729 ierr = VecScatterEnd(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 730 } 731 /* do the local solves */ 732 for (i=0; i<osm->n; ++i) { /* Note that the solves are local, so we can go to osm->n, rather than osm->nmax. */ 733 ierr = KSPSolveTranspose(osm->ksp[i],osm->x[i],osm->y[i]);CHKERRQ(ierr); 734 } 735 ierr = VecZeroEntries(y);CHKERRQ(ierr); 736 if (!(osm->type & PC_GASM_RESTRICT)) { 737 ierr = VecScatterBegin(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 738 ierr = VecScatterEnd(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 739 } else { 740 ierr = VecScatterBegin(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 741 ierr = VecScatterEnd(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 742 } 743 if(osm->pctoouter){ 744 ierr = VecScatterBegin(osm->pctoouter,y,yout,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 745 ierr = VecScatterEnd(osm->pctoouter,y,yout,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 746 } 747 PetscFunctionReturn(0); 748 } 749 750 static PetscErrorCode PCReset_GASM(PC pc) 751 { 752 PC_GASM *osm = (PC_GASM*)pc->data; 753 PetscErrorCode ierr; 754 PetscInt i; 755 756 PetscFunctionBegin; 757 if (osm->ksp) { 758 for (i=0; i<osm->n; i++) { 759 ierr = KSPReset(osm->ksp[i]);CHKERRQ(ierr); 760 } 761 } 762 if (osm->pmat) { 763 if (osm->n > 0) { 764 PetscMPIInt size; 765 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);CHKERRQ(ierr); 766 if (size > 1) { 767 /* osm->pmat is created by MatCreateSubMatricesMPI(), cannot use MatDestroySubMatrices() */ 768 ierr = MatDestroyMatrices(osm->n,&osm->pmat);CHKERRQ(ierr); 769 } else { 770 ierr = MatDestroySubMatrices(osm->n,&osm->pmat);CHKERRQ(ierr); 771 } 772 } 773 } 774 if (osm->x) { 775 for (i=0; i<osm->n; i++) { 776 ierr = VecDestroy(&osm->x[i]);CHKERRQ(ierr); 777 ierr = VecDestroy(&osm->y[i]);CHKERRQ(ierr); 778 } 779 } 780 ierr = VecDestroy(&osm->gx);CHKERRQ(ierr); 781 ierr = VecDestroy(&osm->gy);CHKERRQ(ierr); 782 783 ierr = VecScatterDestroy(&osm->gorestriction);CHKERRQ(ierr); 784 ierr = VecScatterDestroy(&osm->girestriction);CHKERRQ(ierr); 785 if (!osm->user_subdomains) { 786 ierr = PCGASMDestroySubdomains(osm->n,&osm->ois,&osm->iis);CHKERRQ(ierr); 787 osm->N = PETSC_DETERMINE; 788 osm->nmax = PETSC_DETERMINE; 789 } 790 if(osm->pctoouter){ 791 ierr = VecScatterDestroy(&(osm->pctoouter));CHKERRQ(ierr); 792 } 793 if(osm->permutationIS){ 794 ierr = ISDestroy(&(osm->permutationIS));CHKERRQ(ierr); 795 } 796 if(osm->pcx){ 797 ierr = VecDestroy(&(osm->pcx));CHKERRQ(ierr); 798 } 799 if(osm->pcy){ 800 ierr = VecDestroy(&(osm->pcy));CHKERRQ(ierr); 801 } 802 if(osm->permutationP){ 803 ierr = MatDestroy(&(osm->permutationP));CHKERRQ(ierr); 804 } 805 if(osm->pcmat){ 806 ierr = MatDestroy(&osm->pcmat);CHKERRQ(ierr); 807 } 808 PetscFunctionReturn(0); 809 } 810 811 static PetscErrorCode PCDestroy_GASM(PC pc) 812 { 813 PC_GASM *osm = (PC_GASM*)pc->data; 814 PetscErrorCode ierr; 815 PetscInt i; 816 817 PetscFunctionBegin; 818 ierr = PCReset_GASM(pc);CHKERRQ(ierr); 819 /* PCReset will not destroy subdomains, if user_subdomains is true. */ 820 ierr = PCGASMDestroySubdomains(osm->n,&osm->ois,&osm->iis);CHKERRQ(ierr); 821 if (osm->ksp) { 822 for (i=0; i<osm->n; i++) { 823 ierr = KSPDestroy(&osm->ksp[i]);CHKERRQ(ierr); 824 } 825 ierr = PetscFree(osm->ksp);CHKERRQ(ierr); 826 } 827 ierr = PetscFree(osm->x);CHKERRQ(ierr); 828 ierr = PetscFree(osm->y);CHKERRQ(ierr); 829 ierr = PetscFree(pc->data);CHKERRQ(ierr); 830 PetscFunctionReturn(0); 831 } 832 833 static PetscErrorCode PCSetFromOptions_GASM(PetscOptionItems *PetscOptionsObject,PC pc) 834 { 835 PC_GASM *osm = (PC_GASM*)pc->data; 836 PetscErrorCode ierr; 837 PetscInt blocks,ovl; 838 PetscBool symset,flg; 839 PCGASMType gasmtype; 840 841 PetscFunctionBegin; 842 /* set the type to symmetric if matrix is symmetric */ 843 if (!osm->type_set && pc->pmat) { 844 ierr = MatIsSymmetricKnown(pc->pmat,&symset,&flg);CHKERRQ(ierr); 845 if (symset && flg) osm->type = PC_GASM_BASIC; 846 } 847 ierr = PetscOptionsHead(PetscOptionsObject,"Generalized additive Schwarz options");CHKERRQ(ierr); 848 ierr = PetscOptionsBool("-pc_gasm_use_dm_subdomains","If subdomains aren't set, use DMCreateDomainDecomposition() to define subdomains.","PCGASMSetUseDMSubdomains",osm->dm_subdomains,&osm->dm_subdomains,&flg);CHKERRQ(ierr); 849 ierr = PetscOptionsInt("-pc_gasm_total_subdomains","Total number of subdomains across communicator","PCGASMSetTotalSubdomains",osm->N,&blocks,&flg);CHKERRQ(ierr); 850 if (flg) { 851 ierr = PCGASMSetTotalSubdomains(pc,blocks);CHKERRQ(ierr); 852 } 853 ierr = PetscOptionsInt("-pc_gasm_overlap","Number of overlapping degrees of freedom","PCGASMSetOverlap",osm->overlap,&ovl,&flg);CHKERRQ(ierr); 854 if (flg) { 855 ierr = PCGASMSetOverlap(pc,ovl);CHKERRQ(ierr); 856 osm->dm_subdomains = PETSC_FALSE; 857 } 858 flg = PETSC_FALSE; 859 ierr = PetscOptionsEnum("-pc_gasm_type","Type of restriction/extension","PCGASMSetType",PCGASMTypes,(PetscEnum)osm->type,(PetscEnum*)&gasmtype,&flg);CHKERRQ(ierr); 860 if (flg) {ierr = PCGASMSetType(pc,gasmtype);CHKERRQ(ierr);} 861 ierr = PetscOptionsBool("-pc_gasm_use_hierachical_partitioning","use hierarchical partitioning",NULL,osm->hierarchicalpartitioning,&osm->hierarchicalpartitioning,&flg);CHKERRQ(ierr); 862 ierr = PetscOptionsTail();CHKERRQ(ierr); 863 PetscFunctionReturn(0); 864 } 865 866 /*------------------------------------------------------------------------------------*/ 867 868 /*@ 869 PCGASMSetTotalSubdomains - sets the total number of subdomains to use across the 870 communicator. 871 Logically collective on pc 872 873 Input Parameters: 874 + pc - the preconditioner 875 - N - total number of subdomains 876 877 878 Level: beginner 879 880 .keywords: PC, ASM, DM, set, subdomains, additive Schwarz 881 882 .seealso: PCGASMSetSubdomains(), PCGASMSetOverlap() 883 PCGASMCreateSubdomains2D() 884 @*/ 885 PetscErrorCode PCGASMSetTotalSubdomains(PC pc,PetscInt N) 886 { 887 PC_GASM *osm = (PC_GASM*)pc->data; 888 PetscMPIInt size,rank; 889 PetscErrorCode ierr; 890 891 PetscFunctionBegin; 892 if (N < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Total number of subdomains must be 1 or more, got N = %D",N); 893 if (pc->setupcalled) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"PCGASMSetTotalSubdomains() should be called before calling PCSetUp()."); 894 895 ierr = PCGASMDestroySubdomains(osm->n,&osm->iis,&osm->ois);CHKERRQ(ierr); 896 osm->ois = osm->iis = NULL; 897 898 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)pc),&size);CHKERRQ(ierr); 899 ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)pc),&rank);CHKERRQ(ierr); 900 osm->N = N; 901 osm->n = PETSC_DETERMINE; 902 osm->nmax = PETSC_DETERMINE; 903 osm->dm_subdomains = PETSC_FALSE; 904 PetscFunctionReturn(0); 905 } 906 907 908 static PetscErrorCode PCGASMSetSubdomains_GASM(PC pc,PetscInt n,IS iis[],IS ois[]) 909 { 910 PC_GASM *osm = (PC_GASM*)pc->data; 911 PetscErrorCode ierr; 912 PetscInt i; 913 914 PetscFunctionBegin; 915 if (n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Each process must have 1 or more subdomains, got n = %D",n); 916 if (pc->setupcalled) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"PCGASMSetSubdomains() should be called before calling PCSetUp()."); 917 918 ierr = PCGASMDestroySubdomains(osm->n,&osm->iis,&osm->ois);CHKERRQ(ierr); 919 osm->iis = osm->ois = NULL; 920 osm->n = n; 921 osm->N = PETSC_DETERMINE; 922 osm->nmax = PETSC_DETERMINE; 923 if (ois) { 924 ierr = PetscMalloc1(n,&osm->ois);CHKERRQ(ierr); 925 for (i=0; i<n; i++) { 926 ierr = PetscObjectReference((PetscObject)ois[i]);CHKERRQ(ierr); 927 osm->ois[i] = ois[i]; 928 } 929 /* 930 Since the user set the outer subdomains, even if nontrivial overlap was requested via PCGASMSetOverlap(), 931 it will be ignored. To avoid confusion later on (e.g., when viewing the PC), the overlap size is set to -1. 932 */ 933 osm->overlap = -1; 934 /* inner subdomains must be provided */ 935 if (!iis) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"inner indices have to be provided \n"); 936 }/* end if */ 937 if (iis) { 938 ierr = PetscMalloc1(n,&osm->iis);CHKERRQ(ierr); 939 for (i=0; i<n; i++) { 940 ierr = PetscObjectReference((PetscObject)iis[i]);CHKERRQ(ierr); 941 osm->iis[i] = iis[i]; 942 } 943 if (!ois) { 944 osm->ois = NULL; 945 /* if user does not provide outer indices, we will create the corresponding outer indices using osm->overlap =1 in PCSetUp_GASM */ 946 } 947 } 948 #if defined(PETSC_USE_DEBUG) 949 { 950 PetscInt j,rstart,rend,*covered,lsize; 951 const PetscInt *indices; 952 /* check if the inner indices cover and only cover the local portion of the preconditioning matrix */ 953 ierr = MatGetOwnershipRange(pc->pmat,&rstart,&rend);CHKERRQ(ierr); 954 ierr = PetscCalloc1(rend-rstart,&covered);CHKERRQ(ierr); 955 /* check if the current processor owns indices from others */ 956 for (i=0; i<n; i++) { 957 ierr = ISGetIndices(osm->iis[i],&indices);CHKERRQ(ierr); 958 ierr = ISGetLocalSize(osm->iis[i],&lsize);CHKERRQ(ierr); 959 for (j=0; j<lsize; j++) { 960 if (indices[j]<rstart || indices[j]>=rend) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"inner subdomains can not own an index %d from other processors", indices[j]); 961 else if (covered[indices[j]-rstart]==1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"inner subdomains can not have an overlapping index %d ",indices[j]); 962 else covered[indices[j]-rstart] = 1; 963 } 964 ierr = ISRestoreIndices(osm->iis[i],&indices);CHKERRQ(ierr); 965 } 966 /* check if we miss any indices */ 967 for (i=rstart; i<rend; i++) { 968 if (!covered[i-rstart]) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"local entity %d was not covered by inner subdomains",i); 969 } 970 ierr = PetscFree(covered);CHKERRQ(ierr); 971 } 972 #endif 973 if (iis) osm->user_subdomains = PETSC_TRUE; 974 PetscFunctionReturn(0); 975 } 976 977 978 static PetscErrorCode PCGASMSetOverlap_GASM(PC pc,PetscInt ovl) 979 { 980 PC_GASM *osm = (PC_GASM*)pc->data; 981 982 PetscFunctionBegin; 983 if (ovl < 0) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_OUTOFRANGE,"Negative overlap value requested"); 984 if (pc->setupcalled && ovl != osm->overlap) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"PCGASMSetOverlap() should be called before PCSetUp()."); 985 if (!pc->setupcalled) osm->overlap = ovl; 986 PetscFunctionReturn(0); 987 } 988 989 static PetscErrorCode PCGASMSetType_GASM(PC pc,PCGASMType type) 990 { 991 PC_GASM *osm = (PC_GASM*)pc->data; 992 993 PetscFunctionBegin; 994 osm->type = type; 995 osm->type_set = PETSC_TRUE; 996 PetscFunctionReturn(0); 997 } 998 999 static PetscErrorCode PCGASMSetSortIndices_GASM(PC pc,PetscBool doSort) 1000 { 1001 PC_GASM *osm = (PC_GASM*)pc->data; 1002 1003 PetscFunctionBegin; 1004 osm->sort_indices = doSort; 1005 PetscFunctionReturn(0); 1006 } 1007 1008 /* 1009 FIXME: This routine might need to be modified now that multiple ranks per subdomain are allowed. 1010 In particular, it would upset the global subdomain number calculation. 1011 */ 1012 static PetscErrorCode PCGASMGetSubKSP_GASM(PC pc,PetscInt *n,PetscInt *first,KSP **ksp) 1013 { 1014 PC_GASM *osm = (PC_GASM*)pc->data; 1015 PetscErrorCode ierr; 1016 1017 PetscFunctionBegin; 1018 if (osm->n < 1) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ORDER,"Need to call PCSetUP() on PC (or KSPSetUp() on the outer KSP object) before calling here"); 1019 1020 if (n) *n = osm->n; 1021 if (first) { 1022 ierr = MPI_Scan(&osm->n,first,1,MPIU_INT,MPI_SUM,PetscObjectComm((PetscObject)pc));CHKERRQ(ierr); 1023 *first -= osm->n; 1024 } 1025 if (ksp) { 1026 /* Assume that local solves are now different; not necessarily 1027 true, though! This flag is used only for PCView_GASM() */ 1028 *ksp = osm->ksp; 1029 osm->same_subdomain_solvers = PETSC_FALSE; 1030 } 1031 PetscFunctionReturn(0); 1032 } /* PCGASMGetSubKSP_GASM() */ 1033 1034 /*@C 1035 PCGASMSetSubdomains - Sets the subdomains for this processor 1036 for the additive Schwarz preconditioner. 1037 1038 Collective on pc 1039 1040 Input Parameters: 1041 + pc - the preconditioner object 1042 . n - the number of subdomains for this processor 1043 . iis - the index sets that define the inner subdomains (or NULL for PETSc to determine subdomains) 1044 - ois - the index sets that define the outer subdomains (or NULL to use the same as iis, or to construct by expanding iis by the requested overlap) 1045 1046 Notes: 1047 The IS indices use the parallel, global numbering of the vector entries. 1048 Inner subdomains are those where the correction is applied. 1049 Outer subdomains are those where the residual necessary to obtain the 1050 corrections is obtained (see PCGASMType for the use of inner/outer subdomains). 1051 Both inner and outer subdomains can extend over several processors. 1052 This processor's portion of a subdomain is known as a local subdomain. 1053 1054 Inner subdomains can not overlap with each other, do not have any entities from remote processors, 1055 and have to cover the entire local subdomain owned by the current processor. The index sets on each 1056 process should be ordered such that the ith local subdomain is connected to the ith remote subdomain 1057 on another MPI process. 1058 1059 By default the GASM preconditioner uses 1 (local) subdomain per processor. 1060 1061 1062 Level: advanced 1063 1064 .keywords: PC, GASM, set, subdomains, additive Schwarz 1065 1066 .seealso: PCGASMSetNumSubdomains(), PCGASMSetOverlap(), PCGASMGetSubKSP(), 1067 PCGASMCreateSubdomains2D(), PCGASMGetSubdomains() 1068 @*/ 1069 PetscErrorCode PCGASMSetSubdomains(PC pc,PetscInt n,IS iis[],IS ois[]) 1070 { 1071 PC_GASM *osm = (PC_GASM*)pc->data; 1072 PetscErrorCode ierr; 1073 1074 PetscFunctionBegin; 1075 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1076 ierr = PetscTryMethod(pc,"PCGASMSetSubdomains_C",(PC,PetscInt,IS[],IS[]),(pc,n,iis,ois));CHKERRQ(ierr); 1077 osm->dm_subdomains = PETSC_FALSE; 1078 PetscFunctionReturn(0); 1079 } 1080 1081 1082 /*@ 1083 PCGASMSetOverlap - Sets the overlap between a pair of subdomains for the 1084 additive Schwarz preconditioner. Either all or no processors in the 1085 pc communicator must call this routine. 1086 1087 Logically Collective on pc 1088 1089 Input Parameters: 1090 + pc - the preconditioner context 1091 - ovl - the amount of overlap between subdomains (ovl >= 0, default value = 0) 1092 1093 Options Database Key: 1094 . -pc_gasm_overlap <overlap> - Sets overlap 1095 1096 Notes: 1097 By default the GASM preconditioner uses 1 subdomain per processor. To use 1098 multiple subdomain per perocessor or "straddling" subdomains that intersect 1099 multiple processors use PCGASMSetSubdomains() (or option -pc_gasm_total_subdomains <n>). 1100 1101 The overlap defaults to 0, so if one desires that no additional 1102 overlap be computed beyond what may have been set with a call to 1103 PCGASMSetSubdomains(), then ovl must be set to be 0. In particular, if one does 1104 not explicitly set the subdomains in application code, then all overlap would be computed 1105 internally by PETSc, and using an overlap of 0 would result in an GASM 1106 variant that is equivalent to the block Jacobi preconditioner. 1107 1108 Note that one can define initial index sets with any overlap via 1109 PCGASMSetSubdomains(); the routine PCGASMSetOverlap() merely allows 1110 PETSc to extend that overlap further, if desired. 1111 1112 Level: intermediate 1113 1114 .keywords: PC, GASM, set, overlap 1115 1116 .seealso: PCGASMSetSubdomains(), PCGASMGetSubKSP(), 1117 PCGASMCreateSubdomains2D(), PCGASMGetSubdomains() 1118 @*/ 1119 PetscErrorCode PCGASMSetOverlap(PC pc,PetscInt ovl) 1120 { 1121 PetscErrorCode ierr; 1122 PC_GASM *osm = (PC_GASM*)pc->data; 1123 1124 PetscFunctionBegin; 1125 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1126 PetscValidLogicalCollectiveInt(pc,ovl,2); 1127 ierr = PetscTryMethod(pc,"PCGASMSetOverlap_C",(PC,PetscInt),(pc,ovl));CHKERRQ(ierr); 1128 osm->dm_subdomains = PETSC_FALSE; 1129 PetscFunctionReturn(0); 1130 } 1131 1132 /*@ 1133 PCGASMSetType - Sets the type of restriction and interpolation used 1134 for local problems in the additive Schwarz method. 1135 1136 Logically Collective on PC 1137 1138 Input Parameters: 1139 + pc - the preconditioner context 1140 - type - variant of GASM, one of 1141 .vb 1142 PC_GASM_BASIC - full interpolation and restriction 1143 PC_GASM_RESTRICT - full restriction, local processor interpolation 1144 PC_GASM_INTERPOLATE - full interpolation, local processor restriction 1145 PC_GASM_NONE - local processor restriction and interpolation 1146 .ve 1147 1148 Options Database Key: 1149 . -pc_gasm_type [basic,restrict,interpolate,none] - Sets GASM type 1150 1151 Level: intermediate 1152 1153 .keywords: PC, GASM, set, type 1154 1155 .seealso: PCGASMSetSubdomains(), PCGASMGetSubKSP(), 1156 PCGASMCreateSubdomains2D() 1157 @*/ 1158 PetscErrorCode PCGASMSetType(PC pc,PCGASMType type) 1159 { 1160 PetscErrorCode ierr; 1161 1162 PetscFunctionBegin; 1163 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1164 PetscValidLogicalCollectiveEnum(pc,type,2); 1165 ierr = PetscTryMethod(pc,"PCGASMSetType_C",(PC,PCGASMType),(pc,type));CHKERRQ(ierr); 1166 PetscFunctionReturn(0); 1167 } 1168 1169 /*@ 1170 PCGASMSetSortIndices - Determines whether subdomain indices are sorted. 1171 1172 Logically Collective on PC 1173 1174 Input Parameters: 1175 + pc - the preconditioner context 1176 - doSort - sort the subdomain indices 1177 1178 Level: intermediate 1179 1180 .keywords: PC, GASM, set, type 1181 1182 .seealso: PCGASMSetSubdomains(), PCGASMGetSubKSP(), 1183 PCGASMCreateSubdomains2D() 1184 @*/ 1185 PetscErrorCode PCGASMSetSortIndices(PC pc,PetscBool doSort) 1186 { 1187 PetscErrorCode ierr; 1188 1189 PetscFunctionBegin; 1190 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1191 PetscValidLogicalCollectiveBool(pc,doSort,2); 1192 ierr = PetscTryMethod(pc,"PCGASMSetSortIndices_C",(PC,PetscBool),(pc,doSort));CHKERRQ(ierr); 1193 PetscFunctionReturn(0); 1194 } 1195 1196 /*@C 1197 PCGASMGetSubKSP - Gets the local KSP contexts for all blocks on 1198 this processor. 1199 1200 Collective on PC iff first_local is requested 1201 1202 Input Parameter: 1203 . pc - the preconditioner context 1204 1205 Output Parameters: 1206 + n_local - the number of blocks on this processor or NULL 1207 . first_local - the global number of the first block on this processor or NULL, 1208 all processors must request or all must pass NULL 1209 - ksp - the array of KSP contexts 1210 1211 Note: 1212 After PCGASMGetSubKSP() the array of KSPes is not to be freed 1213 1214 Currently for some matrix implementations only 1 block per processor 1215 is supported. 1216 1217 You must call KSPSetUp() before calling PCGASMGetSubKSP(). 1218 1219 Level: advanced 1220 1221 .keywords: PC, GASM, additive Schwarz, get, sub, KSP, context 1222 1223 .seealso: PCGASMSetSubdomains(), PCGASMSetOverlap(), 1224 PCGASMCreateSubdomains2D(), 1225 @*/ 1226 PetscErrorCode PCGASMGetSubKSP(PC pc,PetscInt *n_local,PetscInt *first_local,KSP *ksp[]) 1227 { 1228 PetscErrorCode ierr; 1229 1230 PetscFunctionBegin; 1231 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1232 ierr = PetscUseMethod(pc,"PCGASMGetSubKSP_C",(PC,PetscInt*,PetscInt*,KSP **),(pc,n_local,first_local,ksp));CHKERRQ(ierr); 1233 PetscFunctionReturn(0); 1234 } 1235 1236 /* -------------------------------------------------------------------------------------*/ 1237 /*MC 1238 PCGASM - Use the (restricted) additive Schwarz method, each block is (approximately) solved with 1239 its own KSP object. 1240 1241 Options Database Keys: 1242 + -pc_gasm_total_subdomains <n> - Sets total number of local subdomains to be distributed among processors 1243 . -pc_gasm_view_subdomains - activates the printing of subdomain indices in PCView(), -ksp_view or -snes_view 1244 . -pc_gasm_print_subdomains - activates the printing of subdomain indices in PCSetUp() 1245 . -pc_gasm_overlap <ovl> - Sets overlap by which to (automatically) extend local subdomains 1246 - -pc_gasm_type [basic,restrict,interpolate,none] - Sets GASM type 1247 1248 IMPORTANT: If you run with, for example, 3 blocks on 1 processor or 3 blocks on 3 processors you 1249 will get a different convergence rate due to the default option of -pc_gasm_type restrict. Use 1250 -pc_gasm_type basic to use the standard GASM. 1251 1252 Notes: Each processor can have one or more blocks, but a block cannot be shared by more 1253 than one processor. Defaults to one block per processor. 1254 1255 To set options on the solvers for each block append -sub_ to all the KSP, and PC 1256 options database keys. For example, -sub_pc_type ilu -sub_pc_factor_levels 1 -sub_ksp_type preonly 1257 1258 To set the options on the solvers separate for each block call PCGASMGetSubKSP() 1259 and set the options directly on the resulting KSP object (you can access its PC 1260 with KSPGetPC()) 1261 1262 1263 Level: beginner 1264 1265 Concepts: additive Schwarz method 1266 1267 References: 1268 + 1. - M Dryja, OB Widlund, An additive variant of the Schwarz alternating method for the case of many subregions 1269 Courant Institute, New York University Technical report 1270 - 2. - Barry Smith, Petter Bjorstad, and William Gropp, Domain Decompositions: Parallel Multilevel Methods for Elliptic Partial Differential Equations, 1271 Cambridge University Press. 1272 1273 .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, 1274 PCBJACOBI, PCGASMGetSubKSP(), PCGASMSetSubdomains(), 1275 PCSetModifySubmatrices(), PCGASMSetOverlap(), PCGASMSetType() 1276 1277 M*/ 1278 1279 PETSC_EXTERN PetscErrorCode PCCreate_GASM(PC pc) 1280 { 1281 PetscErrorCode ierr; 1282 PC_GASM *osm; 1283 1284 PetscFunctionBegin; 1285 ierr = PetscNewLog(pc,&osm);CHKERRQ(ierr); 1286 1287 osm->N = PETSC_DETERMINE; 1288 osm->n = PETSC_DECIDE; 1289 osm->nmax = PETSC_DETERMINE; 1290 osm->overlap = 0; 1291 osm->ksp = 0; 1292 osm->gorestriction = 0; 1293 osm->girestriction = 0; 1294 osm->pctoouter = 0; 1295 osm->gx = 0; 1296 osm->gy = 0; 1297 osm->x = 0; 1298 osm->y = 0; 1299 osm->pcx = 0; 1300 osm->pcy = 0; 1301 osm->permutationIS = 0; 1302 osm->permutationP = 0; 1303 osm->pcmat = 0; 1304 osm->ois = 0; 1305 osm->iis = 0; 1306 osm->pmat = 0; 1307 osm->type = PC_GASM_RESTRICT; 1308 osm->same_subdomain_solvers = PETSC_TRUE; 1309 osm->sort_indices = PETSC_TRUE; 1310 osm->dm_subdomains = PETSC_FALSE; 1311 osm->hierarchicalpartitioning = PETSC_FALSE; 1312 1313 pc->data = (void*)osm; 1314 pc->ops->apply = PCApply_GASM; 1315 pc->ops->applytranspose = PCApplyTranspose_GASM; 1316 pc->ops->setup = PCSetUp_GASM; 1317 pc->ops->reset = PCReset_GASM; 1318 pc->ops->destroy = PCDestroy_GASM; 1319 pc->ops->setfromoptions = PCSetFromOptions_GASM; 1320 pc->ops->setuponblocks = PCSetUpOnBlocks_GASM; 1321 pc->ops->view = PCView_GASM; 1322 pc->ops->applyrichardson = 0; 1323 1324 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetSubdomains_C",PCGASMSetSubdomains_GASM);CHKERRQ(ierr); 1325 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetOverlap_C",PCGASMSetOverlap_GASM);CHKERRQ(ierr); 1326 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetType_C",PCGASMSetType_GASM);CHKERRQ(ierr); 1327 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetSortIndices_C",PCGASMSetSortIndices_GASM);CHKERRQ(ierr); 1328 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMGetSubKSP_C",PCGASMGetSubKSP_GASM);CHKERRQ(ierr); 1329 PetscFunctionReturn(0); 1330 } 1331 1332 1333 PetscErrorCode PCGASMCreateLocalSubdomains(Mat A, PetscInt nloc, IS *iis[]) 1334 { 1335 MatPartitioning mpart; 1336 const char *prefix; 1337 void (*f)(void); 1338 PetscInt i,j,rstart,rend,bs; 1339 PetscBool isbaij = PETSC_FALSE,foundpart = PETSC_FALSE; 1340 Mat Ad = NULL, adj; 1341 IS ispart,isnumb,*is; 1342 PetscErrorCode ierr; 1343 1344 PetscFunctionBegin; 1345 if (nloc < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of local subdomains must > 0, got nloc = %D",nloc); 1346 1347 /* Get prefix, row distribution, and block size */ 1348 ierr = MatGetOptionsPrefix(A,&prefix);CHKERRQ(ierr); 1349 ierr = MatGetOwnershipRange(A,&rstart,&rend);CHKERRQ(ierr); 1350 ierr = MatGetBlockSize(A,&bs);CHKERRQ(ierr); 1351 if (rstart/bs*bs != rstart || rend/bs*bs != rend) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"bad row distribution [%D,%D) for matrix block size %D",rstart,rend,bs); 1352 1353 /* Get diagonal block from matrix if possible */ 1354 ierr = MatShellGetOperation(A,MATOP_GET_DIAGONAL_BLOCK,&f);CHKERRQ(ierr); 1355 if (f) { 1356 ierr = MatGetDiagonalBlock(A,&Ad);CHKERRQ(ierr); 1357 } 1358 if (Ad) { 1359 ierr = PetscObjectTypeCompare((PetscObject)Ad,MATSEQBAIJ,&isbaij);CHKERRQ(ierr); 1360 if (!isbaij) {ierr = PetscObjectTypeCompare((PetscObject)Ad,MATSEQSBAIJ,&isbaij);CHKERRQ(ierr);} 1361 } 1362 if (Ad && nloc > 1) { 1363 PetscBool match,done; 1364 /* Try to setup a good matrix partitioning if available */ 1365 ierr = MatPartitioningCreate(PETSC_COMM_SELF,&mpart);CHKERRQ(ierr); 1366 ierr = PetscObjectSetOptionsPrefix((PetscObject)mpart,prefix);CHKERRQ(ierr); 1367 ierr = MatPartitioningSetFromOptions(mpart);CHKERRQ(ierr); 1368 ierr = PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGCURRENT,&match);CHKERRQ(ierr); 1369 if (!match) { 1370 ierr = PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGSQUARE,&match);CHKERRQ(ierr); 1371 } 1372 if (!match) { /* assume a "good" partitioner is available */ 1373 PetscInt na; 1374 const PetscInt *ia,*ja; 1375 ierr = MatGetRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);CHKERRQ(ierr); 1376 if (done) { 1377 /* Build adjacency matrix by hand. Unfortunately a call to 1378 MatConvert(Ad,MATMPIADJ,MAT_INITIAL_MATRIX,&adj) will 1379 remove the block-aij structure and we cannot expect 1380 MatPartitioning to split vertices as we need */ 1381 PetscInt i,j,len,nnz,cnt,*iia=0,*jja=0; 1382 const PetscInt *row; 1383 nnz = 0; 1384 for (i=0; i<na; i++) { /* count number of nonzeros */ 1385 len = ia[i+1] - ia[i]; 1386 row = ja + ia[i]; 1387 for (j=0; j<len; j++) { 1388 if (row[j] == i) { /* don't count diagonal */ 1389 len--; break; 1390 } 1391 } 1392 nnz += len; 1393 } 1394 ierr = PetscMalloc1(na+1,&iia);CHKERRQ(ierr); 1395 ierr = PetscMalloc1(nnz,&jja);CHKERRQ(ierr); 1396 nnz = 0; 1397 iia[0] = 0; 1398 for (i=0; i<na; i++) { /* fill adjacency */ 1399 cnt = 0; 1400 len = ia[i+1] - ia[i]; 1401 row = ja + ia[i]; 1402 for (j=0; j<len; j++) { 1403 if (row[j] != i) jja[nnz+cnt++] = row[j]; /* if not diagonal */ 1404 } 1405 nnz += cnt; 1406 iia[i+1] = nnz; 1407 } 1408 /* Partitioning of the adjacency matrix */ 1409 ierr = MatCreateMPIAdj(PETSC_COMM_SELF,na,na,iia,jja,NULL,&adj);CHKERRQ(ierr); 1410 ierr = MatPartitioningSetAdjacency(mpart,adj);CHKERRQ(ierr); 1411 ierr = MatPartitioningSetNParts(mpart,nloc);CHKERRQ(ierr); 1412 ierr = MatPartitioningApply(mpart,&ispart);CHKERRQ(ierr); 1413 ierr = ISPartitioningToNumbering(ispart,&isnumb);CHKERRQ(ierr); 1414 ierr = MatDestroy(&adj);CHKERRQ(ierr); 1415 foundpart = PETSC_TRUE; 1416 } 1417 ierr = MatRestoreRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);CHKERRQ(ierr); 1418 } 1419 ierr = MatPartitioningDestroy(&mpart);CHKERRQ(ierr); 1420 } 1421 ierr = PetscMalloc1(nloc,&is);CHKERRQ(ierr); 1422 if (!foundpart) { 1423 1424 /* Partitioning by contiguous chunks of rows */ 1425 1426 PetscInt mbs = (rend-rstart)/bs; 1427 PetscInt start = rstart; 1428 for (i=0; i<nloc; i++) { 1429 PetscInt count = (mbs/nloc + ((mbs % nloc) > i)) * bs; 1430 ierr = ISCreateStride(PETSC_COMM_SELF,count,start,1,&is[i]);CHKERRQ(ierr); 1431 start += count; 1432 } 1433 1434 } else { 1435 1436 /* Partitioning by adjacency of diagonal block */ 1437 1438 const PetscInt *numbering; 1439 PetscInt *count,nidx,*indices,*newidx,start=0; 1440 /* Get node count in each partition */ 1441 ierr = PetscMalloc1(nloc,&count);CHKERRQ(ierr); 1442 ierr = ISPartitioningCount(ispart,nloc,count);CHKERRQ(ierr); 1443 if (isbaij && bs > 1) { /* adjust for the block-aij case */ 1444 for (i=0; i<nloc; i++) count[i] *= bs; 1445 } 1446 /* Build indices from node numbering */ 1447 ierr = ISGetLocalSize(isnumb,&nidx);CHKERRQ(ierr); 1448 ierr = PetscMalloc1(nidx,&indices);CHKERRQ(ierr); 1449 for (i=0; i<nidx; i++) indices[i] = i; /* needs to be initialized */ 1450 ierr = ISGetIndices(isnumb,&numbering);CHKERRQ(ierr); 1451 ierr = PetscSortIntWithPermutation(nidx,numbering,indices);CHKERRQ(ierr); 1452 ierr = ISRestoreIndices(isnumb,&numbering);CHKERRQ(ierr); 1453 if (isbaij && bs > 1) { /* adjust for the block-aij case */ 1454 ierr = PetscMalloc1(nidx*bs,&newidx);CHKERRQ(ierr); 1455 for (i=0; i<nidx; i++) { 1456 for (j=0; j<bs; j++) newidx[i*bs+j] = indices[i]*bs + j; 1457 } 1458 ierr = PetscFree(indices);CHKERRQ(ierr); 1459 nidx *= bs; 1460 indices = newidx; 1461 } 1462 /* Shift to get global indices */ 1463 for (i=0; i<nidx; i++) indices[i] += rstart; 1464 1465 /* Build the index sets for each block */ 1466 for (i=0; i<nloc; i++) { 1467 ierr = ISCreateGeneral(PETSC_COMM_SELF,count[i],&indices[start],PETSC_COPY_VALUES,&is[i]);CHKERRQ(ierr); 1468 ierr = ISSort(is[i]);CHKERRQ(ierr); 1469 start += count[i]; 1470 } 1471 1472 ierr = PetscFree(count);CHKERRQ(ierr); 1473 ierr = PetscFree(indices);CHKERRQ(ierr); 1474 ierr = ISDestroy(&isnumb);CHKERRQ(ierr); 1475 ierr = ISDestroy(&ispart);CHKERRQ(ierr); 1476 } 1477 *iis = is; 1478 PetscFunctionReturn(0); 1479 } 1480 1481 PETSC_INTERN PetscErrorCode PCGASMCreateStraddlingSubdomains(Mat A,PetscInt N,PetscInt *n,IS *iis[]) 1482 { 1483 PetscErrorCode ierr; 1484 1485 PetscFunctionBegin; 1486 ierr = MatSubdomainsCreateCoalesce(A,N,n,iis);CHKERRQ(ierr); 1487 PetscFunctionReturn(0); 1488 } 1489 1490 1491 1492 /*@C 1493 PCGASMCreateSubdomains - Creates n index sets defining n nonoverlapping subdomains for the additive 1494 Schwarz preconditioner for a any problem based on its matrix. 1495 1496 Collective 1497 1498 Input Parameters: 1499 + A - The global matrix operator 1500 - N - the number of global subdomains requested 1501 1502 Output Parameters: 1503 + n - the number of subdomains created on this processor 1504 - iis - the array of index sets defining the local inner subdomains (on which the correction is applied) 1505 1506 Level: advanced 1507 1508 Note: When N >= A's communicator size, each subdomain is local -- contained within a single processor. 1509 When N < size, the subdomains are 'straddling' (processor boundaries) and are no longer local. 1510 The resulting subdomains can be use in PCGASMSetSubdomains(pc,n,iss,NULL). The overlapping 1511 outer subdomains will be automatically generated from these according to the requested amount of 1512 overlap; this is currently supported only with local subdomains. 1513 1514 1515 .keywords: PC, GASM, additive Schwarz, create, subdomains, unstructured grid 1516 1517 .seealso: PCGASMSetSubdomains(), PCGASMDestroySubdomains() 1518 @*/ 1519 PetscErrorCode PCGASMCreateSubdomains(Mat A,PetscInt N,PetscInt *n,IS *iis[]) 1520 { 1521 PetscMPIInt size; 1522 PetscErrorCode ierr; 1523 1524 PetscFunctionBegin; 1525 PetscValidHeaderSpecific(A,MAT_CLASSID,1); 1526 PetscValidPointer(iis,4); 1527 1528 if (N < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Number of subdomains must be > 0, N = %D",N); 1529 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)A),&size);CHKERRQ(ierr); 1530 if (N >= size) { 1531 *n = N/size + (N%size); 1532 ierr = PCGASMCreateLocalSubdomains(A,*n,iis);CHKERRQ(ierr); 1533 } else { 1534 ierr = PCGASMCreateStraddlingSubdomains(A,N,n,iis);CHKERRQ(ierr); 1535 } 1536 PetscFunctionReturn(0); 1537 } 1538 1539 /*@C 1540 PCGASMDestroySubdomains - Destroys the index sets created with 1541 PCGASMCreateSubdomains() or PCGASMCreateSubdomains2D. Should be 1542 called after setting subdomains with PCGASMSetSubdomains(). 1543 1544 Collective 1545 1546 Input Parameters: 1547 + n - the number of index sets 1548 . iis - the array of inner subdomains, 1549 - ois - the array of outer subdomains, can be NULL 1550 1551 Level: intermediate 1552 1553 Notes: this is merely a convenience subroutine that walks each list, 1554 destroys each IS on the list, and then frees the list. At the end the 1555 list pointers are set to NULL. 1556 1557 .keywords: PC, GASM, additive Schwarz, create, subdomains, unstructured grid 1558 1559 .seealso: PCGASMCreateSubdomains(), PCGASMSetSubdomains() 1560 @*/ 1561 PetscErrorCode PCGASMDestroySubdomains(PetscInt n,IS **iis,IS **ois) 1562 { 1563 PetscInt i; 1564 PetscErrorCode ierr; 1565 1566 PetscFunctionBegin; 1567 if (n <= 0) PetscFunctionReturn(0); 1568 if (ois) { 1569 PetscValidPointer(ois,3); 1570 if (*ois) { 1571 PetscValidPointer(*ois,3); 1572 for (i=0; i<n; i++) { 1573 ierr = ISDestroy(&(*ois)[i]);CHKERRQ(ierr); 1574 } 1575 ierr = PetscFree((*ois));CHKERRQ(ierr); 1576 } 1577 } 1578 if (iis) { 1579 PetscValidPointer(iis,2); 1580 if (*iis) { 1581 PetscValidPointer(*iis,2); 1582 for (i=0; i<n; i++) { 1583 ierr = ISDestroy(&(*iis)[i]);CHKERRQ(ierr); 1584 } 1585 ierr = PetscFree((*iis));CHKERRQ(ierr); 1586 } 1587 } 1588 PetscFunctionReturn(0); 1589 } 1590 1591 1592 #define PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,xleft_loc,ylow_loc,xright_loc,yhigh_loc,n) \ 1593 { \ 1594 PetscInt first_row = first/M, last_row = last/M+1; \ 1595 /* \ 1596 Compute ylow_loc and yhigh_loc so that (ylow_loc,xleft) and (yhigh_loc,xright) are the corners \ 1597 of the bounding box of the intersection of the subdomain with the local ownership range (local \ 1598 subdomain). \ 1599 Also compute xleft_loc and xright_loc as the lower and upper bounds on the first and last rows \ 1600 of the intersection. \ 1601 */ \ 1602 /* ylow_loc is the grid row containing the first element of the local sumbdomain */ \ 1603 *ylow_loc = PetscMax(first_row,ylow); \ 1604 /* xleft_loc is the offset of first element of the local subdomain within its grid row (might actually be outside the local subdomain) */ \ 1605 *xleft_loc = *ylow_loc==first_row ? PetscMax(first%M,xleft) : xleft; \ 1606 /* yhigh_loc is the grid row above the last local subdomain element */ \ 1607 *yhigh_loc = PetscMin(last_row,yhigh); \ 1608 /* xright is the offset of the end of the local subdomain within its grid row (might actually be outside the local subdomain) */ \ 1609 *xright_loc = *yhigh_loc==last_row ? PetscMin(xright,last%M) : xright; \ 1610 /* Now compute the size of the local subdomain n. */ \ 1611 *n = 0; \ 1612 if (*ylow_loc < *yhigh_loc) { \ 1613 PetscInt width = xright-xleft; \ 1614 *n += width*(*yhigh_loc-*ylow_loc-1); \ 1615 *n += PetscMin(PetscMax(*xright_loc-xleft,0),width); \ 1616 *n -= PetscMin(PetscMax(*xleft_loc-xleft,0), width); \ 1617 } \ 1618 } 1619 1620 1621 1622 /*@ 1623 PCGASMCreateSubdomains2D - Creates the index sets for the overlapping Schwarz 1624 preconditioner for a two-dimensional problem on a regular grid. 1625 1626 Collective 1627 1628 Input Parameters: 1629 + M, N - the global number of grid points in the x and y directions 1630 . Mdomains, Ndomains - the global number of subdomains in the x and y directions 1631 . dof - degrees of freedom per node 1632 - overlap - overlap in mesh lines 1633 1634 Output Parameters: 1635 + Nsub - the number of local subdomains created 1636 . iis - array of index sets defining inner (nonoverlapping) subdomains 1637 - ois - array of index sets defining outer (overlapping, if overlap > 0) subdomains 1638 1639 1640 Level: advanced 1641 1642 .keywords: PC, GASM, additive Schwarz, create, subdomains, 2D, regular grid 1643 1644 .seealso: PCGASMSetSubdomains(), PCGASMGetSubKSP(), PCGASMSetOverlap() 1645 @*/ 1646 PetscErrorCode PCGASMCreateSubdomains2D(PC pc,PetscInt M,PetscInt N,PetscInt Mdomains,PetscInt Ndomains,PetscInt dof,PetscInt overlap,PetscInt *nsub,IS **iis,IS **ois) 1647 { 1648 PetscErrorCode ierr; 1649 PetscMPIInt size, rank; 1650 PetscInt i, j; 1651 PetscInt maxheight, maxwidth; 1652 PetscInt xstart, xleft, xright, xleft_loc, xright_loc; 1653 PetscInt ystart, ylow, yhigh, ylow_loc, yhigh_loc; 1654 PetscInt x[2][2], y[2][2], n[2]; 1655 PetscInt first, last; 1656 PetscInt nidx, *idx; 1657 PetscInt ii,jj,s,q,d; 1658 PetscInt k,kk; 1659 PetscMPIInt color; 1660 MPI_Comm comm, subcomm; 1661 IS **xis = 0, **is = ois, **is_local = iis; 1662 1663 PetscFunctionBegin; 1664 ierr = PetscObjectGetComm((PetscObject)pc, &comm);CHKERRQ(ierr); 1665 ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr); 1666 ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr); 1667 ierr = MatGetOwnershipRange(pc->pmat, &first, &last);CHKERRQ(ierr); 1668 if (first%dof || last%dof) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Matrix row partitioning unsuitable for domain decomposition: local row range (%D,%D) " 1669 "does not respect the number of degrees of freedom per grid point %D", first, last, dof); 1670 1671 /* Determine the number of domains with nonzero intersections with the local ownership range. */ 1672 s = 0; 1673 ystart = 0; 1674 for (j=0; j<Ndomains; ++j) { 1675 maxheight = N/Ndomains + ((N % Ndomains) > j); /* Maximal height of subdomain */ 1676 if (maxheight < 2) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many %D subdomains in the vertical directon for mesh height %D", Ndomains, N); 1677 /* Vertical domain limits with an overlap. */ 1678 ylow = PetscMax(ystart - overlap,0); 1679 yhigh = PetscMin(ystart + maxheight + overlap,N); 1680 xstart = 0; 1681 for (i=0; i<Mdomains; ++i) { 1682 maxwidth = M/Mdomains + ((M % Mdomains) > i); /* Maximal width of subdomain */ 1683 if (maxwidth < 2) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many %D subdomains in the horizontal direction for mesh width %D", Mdomains, M); 1684 /* Horizontal domain limits with an overlap. */ 1685 xleft = PetscMax(xstart - overlap,0); 1686 xright = PetscMin(xstart + maxwidth + overlap,M); 1687 /* 1688 Determine whether this subdomain intersects this processor's ownership range of pc->pmat. 1689 */ 1690 PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,(&xleft_loc),(&ylow_loc),(&xright_loc),(&yhigh_loc),(&nidx)); 1691 if (nidx) ++s; 1692 xstart += maxwidth; 1693 } /* for (i = 0; i < Mdomains; ++i) */ 1694 ystart += maxheight; 1695 } /* for (j = 0; j < Ndomains; ++j) */ 1696 1697 /* Now we can allocate the necessary number of ISs. */ 1698 *nsub = s; 1699 ierr = PetscMalloc1(*nsub,is);CHKERRQ(ierr); 1700 ierr = PetscMalloc1(*nsub,is_local);CHKERRQ(ierr); 1701 s = 0; 1702 ystart = 0; 1703 for (j=0; j<Ndomains; ++j) { 1704 maxheight = N/Ndomains + ((N % Ndomains) > j); /* Maximal height of subdomain */ 1705 if (maxheight < 2) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many %D subdomains in the vertical directon for mesh height %D", Ndomains, N); 1706 /* Vertical domain limits with an overlap. */ 1707 y[0][0] = PetscMax(ystart - overlap,0); 1708 y[0][1] = PetscMin(ystart + maxheight + overlap,N); 1709 /* Vertical domain limits without an overlap. */ 1710 y[1][0] = ystart; 1711 y[1][1] = PetscMin(ystart + maxheight,N); 1712 xstart = 0; 1713 for (i=0; i<Mdomains; ++i) { 1714 maxwidth = M/Mdomains + ((M % Mdomains) > i); /* Maximal width of subdomain */ 1715 if (maxwidth < 2) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many %D subdomains in the horizontal direction for mesh width %D", Mdomains, M); 1716 /* Horizontal domain limits with an overlap. */ 1717 x[0][0] = PetscMax(xstart - overlap,0); 1718 x[0][1] = PetscMin(xstart + maxwidth + overlap,M); 1719 /* Horizontal domain limits without an overlap. */ 1720 x[1][0] = xstart; 1721 x[1][1] = PetscMin(xstart+maxwidth,M); 1722 /* 1723 Determine whether this domain intersects this processor's ownership range of pc->pmat. 1724 Do this twice: first for the domains with overlaps, and once without. 1725 During the first pass create the subcommunicators, and use them on the second pass as well. 1726 */ 1727 for (q = 0; q < 2; ++q) { 1728 PetscBool split = PETSC_FALSE; 1729 /* 1730 domain limits, (xleft, xright) and (ylow, yheigh) are adjusted 1731 according to whether the domain with an overlap or without is considered. 1732 */ 1733 xleft = x[q][0]; xright = x[q][1]; 1734 ylow = y[q][0]; yhigh = y[q][1]; 1735 PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,(&xleft_loc),(&ylow_loc),(&xright_loc),(&yhigh_loc),(&nidx)); 1736 nidx *= dof; 1737 n[q] = nidx; 1738 /* 1739 Based on the counted number of indices in the local domain *with an overlap*, 1740 construct a subcommunicator of all the processors supporting this domain. 1741 Observe that a domain with an overlap might have nontrivial local support, 1742 while the domain without an overlap might not. Hence, the decision to participate 1743 in the subcommunicator must be based on the domain with an overlap. 1744 */ 1745 if (q == 0) { 1746 if (nidx) color = 1; 1747 else color = MPI_UNDEFINED; 1748 ierr = MPI_Comm_split(comm, color, rank, &subcomm);CHKERRQ(ierr); 1749 split = PETSC_TRUE; 1750 } 1751 /* 1752 Proceed only if the number of local indices *with an overlap* is nonzero. 1753 */ 1754 if (n[0]) { 1755 if (q == 0) xis = is; 1756 if (q == 1) { 1757 /* 1758 The IS for the no-overlap subdomain shares a communicator with the overlapping domain. 1759 Moreover, if the overlap is zero, the two ISs are identical. 1760 */ 1761 if (overlap == 0) { 1762 (*is_local)[s] = (*is)[s]; 1763 ierr = PetscObjectReference((PetscObject)(*is)[s]);CHKERRQ(ierr); 1764 continue; 1765 } else { 1766 xis = is_local; 1767 subcomm = ((PetscObject)(*is)[s])->comm; 1768 } 1769 } /* if (q == 1) */ 1770 idx = NULL; 1771 ierr = PetscMalloc1(nidx,&idx);CHKERRQ(ierr); 1772 if (nidx) { 1773 k = 0; 1774 for (jj=ylow_loc; jj<yhigh_loc; ++jj) { 1775 PetscInt x0 = (jj==ylow_loc) ? xleft_loc : xleft; 1776 PetscInt x1 = (jj==yhigh_loc-1) ? xright_loc : xright; 1777 kk = dof*(M*jj + x0); 1778 for (ii=x0; ii<x1; ++ii) { 1779 for (d = 0; d < dof; ++d) { 1780 idx[k++] = kk++; 1781 } 1782 } 1783 } 1784 } 1785 ierr = ISCreateGeneral(subcomm,nidx,idx,PETSC_OWN_POINTER,(*xis)+s);CHKERRQ(ierr); 1786 if (split) { 1787 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 1788 } 1789 }/* if (n[0]) */ 1790 }/* for (q = 0; q < 2; ++q) */ 1791 if (n[0]) ++s; 1792 xstart += maxwidth; 1793 } /* for (i = 0; i < Mdomains; ++i) */ 1794 ystart += maxheight; 1795 } /* for (j = 0; j < Ndomains; ++j) */ 1796 PetscFunctionReturn(0); 1797 } 1798 1799 /*@C 1800 PCGASMGetSubdomains - Gets the subdomains supported on this processor 1801 for the additive Schwarz preconditioner. 1802 1803 Not Collective 1804 1805 Input Parameter: 1806 . pc - the preconditioner context 1807 1808 Output Parameters: 1809 + n - the number of subdomains for this processor (default value = 1) 1810 . iis - the index sets that define the inner subdomains (without overlap) supported on this processor (can be NULL) 1811 - ois - the index sets that define the outer subdomains (with overlap) supported on this processor (can be NULL) 1812 1813 1814 Notes: 1815 The user is responsible for destroying the ISs and freeing the returned arrays. 1816 The IS numbering is in the parallel, global numbering of the vector. 1817 1818 Level: advanced 1819 1820 .keywords: PC, GASM, get, subdomains, additive Schwarz 1821 1822 .seealso: PCGASMSetOverlap(), PCGASMGetSubKSP(), PCGASMCreateSubdomains2D(), 1823 PCGASMSetSubdomains(), PCGASMGetSubmatrices() 1824 @*/ 1825 PetscErrorCode PCGASMGetSubdomains(PC pc,PetscInt *n,IS *iis[],IS *ois[]) 1826 { 1827 PC_GASM *osm; 1828 PetscErrorCode ierr; 1829 PetscBool match; 1830 PetscInt i; 1831 1832 PetscFunctionBegin; 1833 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1834 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1835 if (!match) SETERRQ2(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Incorrect object type: expected %s, got %s instead", PCGASM, ((PetscObject)pc)->type_name); 1836 osm = (PC_GASM*)pc->data; 1837 if (n) *n = osm->n; 1838 if (iis) { 1839 ierr = PetscMalloc1(osm->n, iis);CHKERRQ(ierr); 1840 } 1841 if (ois) { 1842 ierr = PetscMalloc1(osm->n, ois);CHKERRQ(ierr); 1843 } 1844 if (iis || ois) { 1845 for (i = 0; i < osm->n; ++i) { 1846 if (iis) (*iis)[i] = osm->iis[i]; 1847 if (ois) (*ois)[i] = osm->ois[i]; 1848 } 1849 } 1850 PetscFunctionReturn(0); 1851 } 1852 1853 /*@C 1854 PCGASMGetSubmatrices - Gets the local submatrices (for this processor 1855 only) for the additive Schwarz preconditioner. 1856 1857 Not Collective 1858 1859 Input Parameter: 1860 . pc - the preconditioner context 1861 1862 Output Parameters: 1863 + n - the number of matrices for this processor (default value = 1) 1864 - mat - the matrices 1865 1866 Notes: matrices returned by this routine have the same communicators as the index sets (IS) 1867 used to define subdomains in PCGASMSetSubdomains() 1868 Level: advanced 1869 1870 .keywords: PC, GASM, set, local, subdomains, additive Schwarz, block Jacobi 1871 1872 .seealso: PCGASMSetOverlap(), PCGASMGetSubKSP(), 1873 PCGASMCreateSubdomains2D(), PCGASMSetSubdomains(), PCGASMGetSubdomains() 1874 @*/ 1875 PetscErrorCode PCGASMGetSubmatrices(PC pc,PetscInt *n,Mat *mat[]) 1876 { 1877 PC_GASM *osm; 1878 PetscErrorCode ierr; 1879 PetscBool match; 1880 1881 PetscFunctionBegin; 1882 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1883 PetscValidIntPointer(n,2); 1884 if (mat) PetscValidPointer(mat,3); 1885 if (!pc->setupcalled) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must call after KSPSetUP() or PCSetUp()."); 1886 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1887 if (!match) SETERRQ2(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Expected %s, got %s instead", PCGASM, ((PetscObject)pc)->type_name); 1888 osm = (PC_GASM*)pc->data; 1889 if (n) *n = osm->n; 1890 if (mat) *mat = osm->pmat; 1891 PetscFunctionReturn(0); 1892 } 1893 1894 /*@ 1895 PCGASMSetUseDMSubdomains - Indicates whether to use DMCreateDomainDecomposition() to define the subdomains, whenever possible. 1896 Logically Collective 1897 1898 Input Parameter: 1899 + pc - the preconditioner 1900 - flg - boolean indicating whether to use subdomains defined by the DM 1901 1902 Options Database Key: 1903 . -pc_gasm_dm_subdomains -pc_gasm_overlap -pc_gasm_total_subdomains 1904 1905 Level: intermediate 1906 1907 Notes: 1908 PCGASMSetSubdomains(), PCGASMSetTotalSubdomains() or PCGASMSetOverlap() take precedence over PCGASMSetUseDMSubdomains(), 1909 so setting PCGASMSetSubdomains() with nontrivial subdomain ISs or any of PCGASMSetTotalSubdomains() and PCGASMSetOverlap() 1910 automatically turns the latter off. 1911 1912 .keywords: PC, ASM, DM, set, subdomains, additive Schwarz 1913 1914 .seealso: PCGASMGetUseDMSubdomains(), PCGASMSetSubdomains(), PCGASMSetOverlap() 1915 PCGASMCreateSubdomains2D() 1916 @*/ 1917 PetscErrorCode PCGASMSetUseDMSubdomains(PC pc,PetscBool flg) 1918 { 1919 PC_GASM *osm = (PC_GASM*)pc->data; 1920 PetscErrorCode ierr; 1921 PetscBool match; 1922 1923 PetscFunctionBegin; 1924 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1925 PetscValidLogicalCollectiveBool(pc,flg,2); 1926 if (pc->setupcalled) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for a setup PC."); 1927 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1928 if (match) { 1929 if (!osm->user_subdomains && osm->N == PETSC_DETERMINE && osm->overlap < 0) { 1930 osm->dm_subdomains = flg; 1931 } 1932 } 1933 PetscFunctionReturn(0); 1934 } 1935 1936 /*@ 1937 PCGASMGetUseDMSubdomains - Returns flag indicating whether to use DMCreateDomainDecomposition() to define the subdomains, whenever possible. 1938 Not Collective 1939 1940 Input Parameter: 1941 . pc - the preconditioner 1942 1943 Output Parameter: 1944 . flg - boolean indicating whether to use subdomains defined by the DM 1945 1946 Level: intermediate 1947 1948 .keywords: PC, ASM, DM, set, subdomains, additive Schwarz 1949 1950 .seealso: PCGASMSetUseDMSubdomains(), PCGASMSetOverlap() 1951 PCGASMCreateSubdomains2D() 1952 @*/ 1953 PetscErrorCode PCGASMGetUseDMSubdomains(PC pc,PetscBool* flg) 1954 { 1955 PC_GASM *osm = (PC_GASM*)pc->data; 1956 PetscErrorCode ierr; 1957 PetscBool match; 1958 1959 PetscFunctionBegin; 1960 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1961 PetscValidPointer(flg,2); 1962 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1963 if (match) { 1964 if (flg) *flg = osm->dm_subdomains; 1965 } 1966 PetscFunctionReturn(0); 1967 } 1968