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: Blocks can be shared by multiple processes. 1253 1254 To set options on the solvers for each block append -sub_ to all the KSP, and PC 1255 options database keys. For example, -sub_pc_type ilu -sub_pc_factor_levels 1 -sub_ksp_type preonly 1256 1257 To set the options on the solvers separate for each block call PCGASMGetSubKSP() 1258 and set the options directly on the resulting KSP object (you can access its PC 1259 with KSPGetPC()) 1260 1261 1262 Level: beginner 1263 1264 Concepts: additive Schwarz method 1265 1266 References: 1267 + 1. - M Dryja, OB Widlund, An additive variant of the Schwarz alternating method for the case of many subregions 1268 Courant Institute, New York University Technical report 1269 - 2. - Barry Smith, Petter Bjorstad, and William Gropp, Domain Decompositions: Parallel Multilevel Methods for Elliptic Partial Differential Equations, 1270 Cambridge University Press. 1271 1272 .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, 1273 PCBJACOBI, PCGASMGetSubKSP(), PCGASMSetSubdomains(), 1274 PCSetModifySubmatrices(), PCGASMSetOverlap(), PCGASMSetType() 1275 1276 M*/ 1277 1278 PETSC_EXTERN PetscErrorCode PCCreate_GASM(PC pc) 1279 { 1280 PetscErrorCode ierr; 1281 PC_GASM *osm; 1282 1283 PetscFunctionBegin; 1284 ierr = PetscNewLog(pc,&osm);CHKERRQ(ierr); 1285 1286 osm->N = PETSC_DETERMINE; 1287 osm->n = PETSC_DECIDE; 1288 osm->nmax = PETSC_DETERMINE; 1289 osm->overlap = 0; 1290 osm->ksp = 0; 1291 osm->gorestriction = 0; 1292 osm->girestriction = 0; 1293 osm->pctoouter = 0; 1294 osm->gx = 0; 1295 osm->gy = 0; 1296 osm->x = 0; 1297 osm->y = 0; 1298 osm->pcx = 0; 1299 osm->pcy = 0; 1300 osm->permutationIS = 0; 1301 osm->permutationP = 0; 1302 osm->pcmat = 0; 1303 osm->ois = 0; 1304 osm->iis = 0; 1305 osm->pmat = 0; 1306 osm->type = PC_GASM_RESTRICT; 1307 osm->same_subdomain_solvers = PETSC_TRUE; 1308 osm->sort_indices = PETSC_TRUE; 1309 osm->dm_subdomains = PETSC_FALSE; 1310 osm->hierarchicalpartitioning = PETSC_FALSE; 1311 1312 pc->data = (void*)osm; 1313 pc->ops->apply = PCApply_GASM; 1314 pc->ops->applytranspose = PCApplyTranspose_GASM; 1315 pc->ops->setup = PCSetUp_GASM; 1316 pc->ops->reset = PCReset_GASM; 1317 pc->ops->destroy = PCDestroy_GASM; 1318 pc->ops->setfromoptions = PCSetFromOptions_GASM; 1319 pc->ops->setuponblocks = PCSetUpOnBlocks_GASM; 1320 pc->ops->view = PCView_GASM; 1321 pc->ops->applyrichardson = 0; 1322 1323 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetSubdomains_C",PCGASMSetSubdomains_GASM);CHKERRQ(ierr); 1324 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetOverlap_C",PCGASMSetOverlap_GASM);CHKERRQ(ierr); 1325 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetType_C",PCGASMSetType_GASM);CHKERRQ(ierr); 1326 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMSetSortIndices_C",PCGASMSetSortIndices_GASM);CHKERRQ(ierr); 1327 ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGASMGetSubKSP_C",PCGASMGetSubKSP_GASM);CHKERRQ(ierr); 1328 PetscFunctionReturn(0); 1329 } 1330 1331 1332 PetscErrorCode PCGASMCreateLocalSubdomains(Mat A, PetscInt nloc, IS *iis[]) 1333 { 1334 MatPartitioning mpart; 1335 const char *prefix; 1336 PetscInt i,j,rstart,rend,bs; 1337 PetscBool hasop, isbaij = PETSC_FALSE,foundpart = PETSC_FALSE; 1338 Mat Ad = NULL, adj; 1339 IS ispart,isnumb,*is; 1340 PetscErrorCode ierr; 1341 1342 PetscFunctionBegin; 1343 if (nloc < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of local subdomains must > 0, got nloc = %D",nloc); 1344 1345 /* Get prefix, row distribution, and block size */ 1346 ierr = MatGetOptionsPrefix(A,&prefix);CHKERRQ(ierr); 1347 ierr = MatGetOwnershipRange(A,&rstart,&rend);CHKERRQ(ierr); 1348 ierr = MatGetBlockSize(A,&bs);CHKERRQ(ierr); 1349 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); 1350 1351 /* Get diagonal block from matrix if possible */ 1352 ierr = MatHasOperation(A,MATOP_GET_DIAGONAL_BLOCK,&hasop);CHKERRQ(ierr); 1353 if (hasop) { 1354 ierr = MatGetDiagonalBlock(A,&Ad);CHKERRQ(ierr); 1355 } 1356 if (Ad) { 1357 ierr = PetscObjectTypeCompare((PetscObject)Ad,MATSEQBAIJ,&isbaij);CHKERRQ(ierr); 1358 if (!isbaij) {ierr = PetscObjectTypeCompare((PetscObject)Ad,MATSEQSBAIJ,&isbaij);CHKERRQ(ierr);} 1359 } 1360 if (Ad && nloc > 1) { 1361 PetscBool match,done; 1362 /* Try to setup a good matrix partitioning if available */ 1363 ierr = MatPartitioningCreate(PETSC_COMM_SELF,&mpart);CHKERRQ(ierr); 1364 ierr = PetscObjectSetOptionsPrefix((PetscObject)mpart,prefix);CHKERRQ(ierr); 1365 ierr = MatPartitioningSetFromOptions(mpart);CHKERRQ(ierr); 1366 ierr = PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGCURRENT,&match);CHKERRQ(ierr); 1367 if (!match) { 1368 ierr = PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGSQUARE,&match);CHKERRQ(ierr); 1369 } 1370 if (!match) { /* assume a "good" partitioner is available */ 1371 PetscInt na; 1372 const PetscInt *ia,*ja; 1373 ierr = MatGetRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);CHKERRQ(ierr); 1374 if (done) { 1375 /* Build adjacency matrix by hand. Unfortunately a call to 1376 MatConvert(Ad,MATMPIADJ,MAT_INITIAL_MATRIX,&adj) will 1377 remove the block-aij structure and we cannot expect 1378 MatPartitioning to split vertices as we need */ 1379 PetscInt i,j,len,nnz,cnt,*iia=0,*jja=0; 1380 const PetscInt *row; 1381 nnz = 0; 1382 for (i=0; i<na; i++) { /* count number of nonzeros */ 1383 len = ia[i+1] - ia[i]; 1384 row = ja + ia[i]; 1385 for (j=0; j<len; j++) { 1386 if (row[j] == i) { /* don't count diagonal */ 1387 len--; break; 1388 } 1389 } 1390 nnz += len; 1391 } 1392 ierr = PetscMalloc1(na+1,&iia);CHKERRQ(ierr); 1393 ierr = PetscMalloc1(nnz,&jja);CHKERRQ(ierr); 1394 nnz = 0; 1395 iia[0] = 0; 1396 for (i=0; i<na; i++) { /* fill adjacency */ 1397 cnt = 0; 1398 len = ia[i+1] - ia[i]; 1399 row = ja + ia[i]; 1400 for (j=0; j<len; j++) { 1401 if (row[j] != i) jja[nnz+cnt++] = row[j]; /* if not diagonal */ 1402 } 1403 nnz += cnt; 1404 iia[i+1] = nnz; 1405 } 1406 /* Partitioning of the adjacency matrix */ 1407 ierr = MatCreateMPIAdj(PETSC_COMM_SELF,na,na,iia,jja,NULL,&adj);CHKERRQ(ierr); 1408 ierr = MatPartitioningSetAdjacency(mpart,adj);CHKERRQ(ierr); 1409 ierr = MatPartitioningSetNParts(mpart,nloc);CHKERRQ(ierr); 1410 ierr = MatPartitioningApply(mpart,&ispart);CHKERRQ(ierr); 1411 ierr = ISPartitioningToNumbering(ispart,&isnumb);CHKERRQ(ierr); 1412 ierr = MatDestroy(&adj);CHKERRQ(ierr); 1413 foundpart = PETSC_TRUE; 1414 } 1415 ierr = MatRestoreRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);CHKERRQ(ierr); 1416 } 1417 ierr = MatPartitioningDestroy(&mpart);CHKERRQ(ierr); 1418 } 1419 ierr = PetscMalloc1(nloc,&is);CHKERRQ(ierr); 1420 if (!foundpart) { 1421 1422 /* Partitioning by contiguous chunks of rows */ 1423 1424 PetscInt mbs = (rend-rstart)/bs; 1425 PetscInt start = rstart; 1426 for (i=0; i<nloc; i++) { 1427 PetscInt count = (mbs/nloc + ((mbs % nloc) > i)) * bs; 1428 ierr = ISCreateStride(PETSC_COMM_SELF,count,start,1,&is[i]);CHKERRQ(ierr); 1429 start += count; 1430 } 1431 1432 } else { 1433 1434 /* Partitioning by adjacency of diagonal block */ 1435 1436 const PetscInt *numbering; 1437 PetscInt *count,nidx,*indices,*newidx,start=0; 1438 /* Get node count in each partition */ 1439 ierr = PetscMalloc1(nloc,&count);CHKERRQ(ierr); 1440 ierr = ISPartitioningCount(ispart,nloc,count);CHKERRQ(ierr); 1441 if (isbaij && bs > 1) { /* adjust for the block-aij case */ 1442 for (i=0; i<nloc; i++) count[i] *= bs; 1443 } 1444 /* Build indices from node numbering */ 1445 ierr = ISGetLocalSize(isnumb,&nidx);CHKERRQ(ierr); 1446 ierr = PetscMalloc1(nidx,&indices);CHKERRQ(ierr); 1447 for (i=0; i<nidx; i++) indices[i] = i; /* needs to be initialized */ 1448 ierr = ISGetIndices(isnumb,&numbering);CHKERRQ(ierr); 1449 ierr = PetscSortIntWithPermutation(nidx,numbering,indices);CHKERRQ(ierr); 1450 ierr = ISRestoreIndices(isnumb,&numbering);CHKERRQ(ierr); 1451 if (isbaij && bs > 1) { /* adjust for the block-aij case */ 1452 ierr = PetscMalloc1(nidx*bs,&newidx);CHKERRQ(ierr); 1453 for (i=0; i<nidx; i++) { 1454 for (j=0; j<bs; j++) newidx[i*bs+j] = indices[i]*bs + j; 1455 } 1456 ierr = PetscFree(indices);CHKERRQ(ierr); 1457 nidx *= bs; 1458 indices = newidx; 1459 } 1460 /* Shift to get global indices */ 1461 for (i=0; i<nidx; i++) indices[i] += rstart; 1462 1463 /* Build the index sets for each block */ 1464 for (i=0; i<nloc; i++) { 1465 ierr = ISCreateGeneral(PETSC_COMM_SELF,count[i],&indices[start],PETSC_COPY_VALUES,&is[i]);CHKERRQ(ierr); 1466 ierr = ISSort(is[i]);CHKERRQ(ierr); 1467 start += count[i]; 1468 } 1469 1470 ierr = PetscFree(count);CHKERRQ(ierr); 1471 ierr = PetscFree(indices);CHKERRQ(ierr); 1472 ierr = ISDestroy(&isnumb);CHKERRQ(ierr); 1473 ierr = ISDestroy(&ispart);CHKERRQ(ierr); 1474 } 1475 *iis = is; 1476 PetscFunctionReturn(0); 1477 } 1478 1479 PETSC_INTERN PetscErrorCode PCGASMCreateStraddlingSubdomains(Mat A,PetscInt N,PetscInt *n,IS *iis[]) 1480 { 1481 PetscErrorCode ierr; 1482 1483 PetscFunctionBegin; 1484 ierr = MatSubdomainsCreateCoalesce(A,N,n,iis);CHKERRQ(ierr); 1485 PetscFunctionReturn(0); 1486 } 1487 1488 1489 1490 /*@C 1491 PCGASMCreateSubdomains - Creates n index sets defining n nonoverlapping subdomains for the additive 1492 Schwarz preconditioner for a any problem based on its matrix. 1493 1494 Collective 1495 1496 Input Parameters: 1497 + A - The global matrix operator 1498 - N - the number of global subdomains requested 1499 1500 Output Parameters: 1501 + n - the number of subdomains created on this processor 1502 - iis - the array of index sets defining the local inner subdomains (on which the correction is applied) 1503 1504 Level: advanced 1505 1506 Note: When N >= A's communicator size, each subdomain is local -- contained within a single processor. 1507 When N < size, the subdomains are 'straddling' (processor boundaries) and are no longer local. 1508 The resulting subdomains can be use in PCGASMSetSubdomains(pc,n,iss,NULL). The overlapping 1509 outer subdomains will be automatically generated from these according to the requested amount of 1510 overlap; this is currently supported only with local subdomains. 1511 1512 1513 .keywords: PC, GASM, additive Schwarz, create, subdomains, unstructured grid 1514 1515 .seealso: PCGASMSetSubdomains(), PCGASMDestroySubdomains() 1516 @*/ 1517 PetscErrorCode PCGASMCreateSubdomains(Mat A,PetscInt N,PetscInt *n,IS *iis[]) 1518 { 1519 PetscMPIInt size; 1520 PetscErrorCode ierr; 1521 1522 PetscFunctionBegin; 1523 PetscValidHeaderSpecific(A,MAT_CLASSID,1); 1524 PetscValidPointer(iis,4); 1525 1526 if (N < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Number of subdomains must be > 0, N = %D",N); 1527 ierr = MPI_Comm_size(PetscObjectComm((PetscObject)A),&size);CHKERRQ(ierr); 1528 if (N >= size) { 1529 *n = N/size + (N%size); 1530 ierr = PCGASMCreateLocalSubdomains(A,*n,iis);CHKERRQ(ierr); 1531 } else { 1532 ierr = PCGASMCreateStraddlingSubdomains(A,N,n,iis);CHKERRQ(ierr); 1533 } 1534 PetscFunctionReturn(0); 1535 } 1536 1537 /*@C 1538 PCGASMDestroySubdomains - Destroys the index sets created with 1539 PCGASMCreateSubdomains() or PCGASMCreateSubdomains2D. Should be 1540 called after setting subdomains with PCGASMSetSubdomains(). 1541 1542 Collective 1543 1544 Input Parameters: 1545 + n - the number of index sets 1546 . iis - the array of inner subdomains, 1547 - ois - the array of outer subdomains, can be NULL 1548 1549 Level: intermediate 1550 1551 Notes: this is merely a convenience subroutine that walks each list, 1552 destroys each IS on the list, and then frees the list. At the end the 1553 list pointers are set to NULL. 1554 1555 .keywords: PC, GASM, additive Schwarz, create, subdomains, unstructured grid 1556 1557 .seealso: PCGASMCreateSubdomains(), PCGASMSetSubdomains() 1558 @*/ 1559 PetscErrorCode PCGASMDestroySubdomains(PetscInt n,IS **iis,IS **ois) 1560 { 1561 PetscInt i; 1562 PetscErrorCode ierr; 1563 1564 PetscFunctionBegin; 1565 if (n <= 0) PetscFunctionReturn(0); 1566 if (ois) { 1567 PetscValidPointer(ois,3); 1568 if (*ois) { 1569 PetscValidPointer(*ois,3); 1570 for (i=0; i<n; i++) { 1571 ierr = ISDestroy(&(*ois)[i]);CHKERRQ(ierr); 1572 } 1573 ierr = PetscFree((*ois));CHKERRQ(ierr); 1574 } 1575 } 1576 if (iis) { 1577 PetscValidPointer(iis,2); 1578 if (*iis) { 1579 PetscValidPointer(*iis,2); 1580 for (i=0; i<n; i++) { 1581 ierr = ISDestroy(&(*iis)[i]);CHKERRQ(ierr); 1582 } 1583 ierr = PetscFree((*iis));CHKERRQ(ierr); 1584 } 1585 } 1586 PetscFunctionReturn(0); 1587 } 1588 1589 1590 #define PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,xleft_loc,ylow_loc,xright_loc,yhigh_loc,n) \ 1591 { \ 1592 PetscInt first_row = first/M, last_row = last/M+1; \ 1593 /* \ 1594 Compute ylow_loc and yhigh_loc so that (ylow_loc,xleft) and (yhigh_loc,xright) are the corners \ 1595 of the bounding box of the intersection of the subdomain with the local ownership range (local \ 1596 subdomain). \ 1597 Also compute xleft_loc and xright_loc as the lower and upper bounds on the first and last rows \ 1598 of the intersection. \ 1599 */ \ 1600 /* ylow_loc is the grid row containing the first element of the local sumbdomain */ \ 1601 *ylow_loc = PetscMax(first_row,ylow); \ 1602 /* xleft_loc is the offset of first element of the local subdomain within its grid row (might actually be outside the local subdomain) */ \ 1603 *xleft_loc = *ylow_loc==first_row ? PetscMax(first%M,xleft) : xleft; \ 1604 /* yhigh_loc is the grid row above the last local subdomain element */ \ 1605 *yhigh_loc = PetscMin(last_row,yhigh); \ 1606 /* xright is the offset of the end of the local subdomain within its grid row (might actually be outside the local subdomain) */ \ 1607 *xright_loc = *yhigh_loc==last_row ? PetscMin(xright,last%M) : xright; \ 1608 /* Now compute the size of the local subdomain n. */ \ 1609 *n = 0; \ 1610 if (*ylow_loc < *yhigh_loc) { \ 1611 PetscInt width = xright-xleft; \ 1612 *n += width*(*yhigh_loc-*ylow_loc-1); \ 1613 *n += PetscMin(PetscMax(*xright_loc-xleft,0),width); \ 1614 *n -= PetscMin(PetscMax(*xleft_loc-xleft,0), width); \ 1615 } \ 1616 } 1617 1618 1619 1620 /*@ 1621 PCGASMCreateSubdomains2D - Creates the index sets for the overlapping Schwarz 1622 preconditioner for a two-dimensional problem on a regular grid. 1623 1624 Collective 1625 1626 Input Parameters: 1627 + M, N - the global number of grid points in the x and y directions 1628 . Mdomains, Ndomains - the global number of subdomains in the x and y directions 1629 . dof - degrees of freedom per node 1630 - overlap - overlap in mesh lines 1631 1632 Output Parameters: 1633 + Nsub - the number of local subdomains created 1634 . iis - array of index sets defining inner (nonoverlapping) subdomains 1635 - ois - array of index sets defining outer (overlapping, if overlap > 0) subdomains 1636 1637 1638 Level: advanced 1639 1640 .keywords: PC, GASM, additive Schwarz, create, subdomains, 2D, regular grid 1641 1642 .seealso: PCGASMSetSubdomains(), PCGASMGetSubKSP(), PCGASMSetOverlap() 1643 @*/ 1644 PetscErrorCode PCGASMCreateSubdomains2D(PC pc,PetscInt M,PetscInt N,PetscInt Mdomains,PetscInt Ndomains,PetscInt dof,PetscInt overlap,PetscInt *nsub,IS **iis,IS **ois) 1645 { 1646 PetscErrorCode ierr; 1647 PetscMPIInt size, rank; 1648 PetscInt i, j; 1649 PetscInt maxheight, maxwidth; 1650 PetscInt xstart, xleft, xright, xleft_loc, xright_loc; 1651 PetscInt ystart, ylow, yhigh, ylow_loc, yhigh_loc; 1652 PetscInt x[2][2], y[2][2], n[2]; 1653 PetscInt first, last; 1654 PetscInt nidx, *idx; 1655 PetscInt ii,jj,s,q,d; 1656 PetscInt k,kk; 1657 PetscMPIInt color; 1658 MPI_Comm comm, subcomm; 1659 IS **xis = 0, **is = ois, **is_local = iis; 1660 1661 PetscFunctionBegin; 1662 ierr = PetscObjectGetComm((PetscObject)pc, &comm);CHKERRQ(ierr); 1663 ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr); 1664 ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr); 1665 ierr = MatGetOwnershipRange(pc->pmat, &first, &last);CHKERRQ(ierr); 1666 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) " 1667 "does not respect the number of degrees of freedom per grid point %D", first, last, dof); 1668 1669 /* Determine the number of domains with nonzero intersections with the local ownership range. */ 1670 s = 0; 1671 ystart = 0; 1672 for (j=0; j<Ndomains; ++j) { 1673 maxheight = N/Ndomains + ((N % Ndomains) > j); /* Maximal height of subdomain */ 1674 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); 1675 /* Vertical domain limits with an overlap. */ 1676 ylow = PetscMax(ystart - overlap,0); 1677 yhigh = PetscMin(ystart + maxheight + overlap,N); 1678 xstart = 0; 1679 for (i=0; i<Mdomains; ++i) { 1680 maxwidth = M/Mdomains + ((M % Mdomains) > i); /* Maximal width of subdomain */ 1681 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); 1682 /* Horizontal domain limits with an overlap. */ 1683 xleft = PetscMax(xstart - overlap,0); 1684 xright = PetscMin(xstart + maxwidth + overlap,M); 1685 /* 1686 Determine whether this subdomain intersects this processor's ownership range of pc->pmat. 1687 */ 1688 PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,(&xleft_loc),(&ylow_loc),(&xright_loc),(&yhigh_loc),(&nidx)); 1689 if (nidx) ++s; 1690 xstart += maxwidth; 1691 } /* for (i = 0; i < Mdomains; ++i) */ 1692 ystart += maxheight; 1693 } /* for (j = 0; j < Ndomains; ++j) */ 1694 1695 /* Now we can allocate the necessary number of ISs. */ 1696 *nsub = s; 1697 ierr = PetscMalloc1(*nsub,is);CHKERRQ(ierr); 1698 ierr = PetscMalloc1(*nsub,is_local);CHKERRQ(ierr); 1699 s = 0; 1700 ystart = 0; 1701 for (j=0; j<Ndomains; ++j) { 1702 maxheight = N/Ndomains + ((N % Ndomains) > j); /* Maximal height of subdomain */ 1703 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); 1704 /* Vertical domain limits with an overlap. */ 1705 y[0][0] = PetscMax(ystart - overlap,0); 1706 y[0][1] = PetscMin(ystart + maxheight + overlap,N); 1707 /* Vertical domain limits without an overlap. */ 1708 y[1][0] = ystart; 1709 y[1][1] = PetscMin(ystart + maxheight,N); 1710 xstart = 0; 1711 for (i=0; i<Mdomains; ++i) { 1712 maxwidth = M/Mdomains + ((M % Mdomains) > i); /* Maximal width of subdomain */ 1713 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); 1714 /* Horizontal domain limits with an overlap. */ 1715 x[0][0] = PetscMax(xstart - overlap,0); 1716 x[0][1] = PetscMin(xstart + maxwidth + overlap,M); 1717 /* Horizontal domain limits without an overlap. */ 1718 x[1][0] = xstart; 1719 x[1][1] = PetscMin(xstart+maxwidth,M); 1720 /* 1721 Determine whether this domain intersects this processor's ownership range of pc->pmat. 1722 Do this twice: first for the domains with overlaps, and once without. 1723 During the first pass create the subcommunicators, and use them on the second pass as well. 1724 */ 1725 for (q = 0; q < 2; ++q) { 1726 PetscBool split = PETSC_FALSE; 1727 /* 1728 domain limits, (xleft, xright) and (ylow, yheigh) are adjusted 1729 according to whether the domain with an overlap or without is considered. 1730 */ 1731 xleft = x[q][0]; xright = x[q][1]; 1732 ylow = y[q][0]; yhigh = y[q][1]; 1733 PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,(&xleft_loc),(&ylow_loc),(&xright_loc),(&yhigh_loc),(&nidx)); 1734 nidx *= dof; 1735 n[q] = nidx; 1736 /* 1737 Based on the counted number of indices in the local domain *with an overlap*, 1738 construct a subcommunicator of all the processors supporting this domain. 1739 Observe that a domain with an overlap might have nontrivial local support, 1740 while the domain without an overlap might not. Hence, the decision to participate 1741 in the subcommunicator must be based on the domain with an overlap. 1742 */ 1743 if (q == 0) { 1744 if (nidx) color = 1; 1745 else color = MPI_UNDEFINED; 1746 ierr = MPI_Comm_split(comm, color, rank, &subcomm);CHKERRQ(ierr); 1747 split = PETSC_TRUE; 1748 } 1749 /* 1750 Proceed only if the number of local indices *with an overlap* is nonzero. 1751 */ 1752 if (n[0]) { 1753 if (q == 0) xis = is; 1754 if (q == 1) { 1755 /* 1756 The IS for the no-overlap subdomain shares a communicator with the overlapping domain. 1757 Moreover, if the overlap is zero, the two ISs are identical. 1758 */ 1759 if (overlap == 0) { 1760 (*is_local)[s] = (*is)[s]; 1761 ierr = PetscObjectReference((PetscObject)(*is)[s]);CHKERRQ(ierr); 1762 continue; 1763 } else { 1764 xis = is_local; 1765 subcomm = ((PetscObject)(*is)[s])->comm; 1766 } 1767 } /* if (q == 1) */ 1768 idx = NULL; 1769 ierr = PetscMalloc1(nidx,&idx);CHKERRQ(ierr); 1770 if (nidx) { 1771 k = 0; 1772 for (jj=ylow_loc; jj<yhigh_loc; ++jj) { 1773 PetscInt x0 = (jj==ylow_loc) ? xleft_loc : xleft; 1774 PetscInt x1 = (jj==yhigh_loc-1) ? xright_loc : xright; 1775 kk = dof*(M*jj + x0); 1776 for (ii=x0; ii<x1; ++ii) { 1777 for (d = 0; d < dof; ++d) { 1778 idx[k++] = kk++; 1779 } 1780 } 1781 } 1782 } 1783 ierr = ISCreateGeneral(subcomm,nidx,idx,PETSC_OWN_POINTER,(*xis)+s);CHKERRQ(ierr); 1784 if (split) { 1785 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 1786 } 1787 }/* if (n[0]) */ 1788 }/* for (q = 0; q < 2; ++q) */ 1789 if (n[0]) ++s; 1790 xstart += maxwidth; 1791 } /* for (i = 0; i < Mdomains; ++i) */ 1792 ystart += maxheight; 1793 } /* for (j = 0; j < Ndomains; ++j) */ 1794 PetscFunctionReturn(0); 1795 } 1796 1797 /*@C 1798 PCGASMGetSubdomains - Gets the subdomains supported on this processor 1799 for the additive Schwarz preconditioner. 1800 1801 Not Collective 1802 1803 Input Parameter: 1804 . pc - the preconditioner context 1805 1806 Output Parameters: 1807 + n - the number of subdomains for this processor (default value = 1) 1808 . iis - the index sets that define the inner subdomains (without overlap) supported on this processor (can be NULL) 1809 - ois - the index sets that define the outer subdomains (with overlap) supported on this processor (can be NULL) 1810 1811 1812 Notes: 1813 The user is responsible for destroying the ISs and freeing the returned arrays. 1814 The IS numbering is in the parallel, global numbering of the vector. 1815 1816 Level: advanced 1817 1818 .keywords: PC, GASM, get, subdomains, additive Schwarz 1819 1820 .seealso: PCGASMSetOverlap(), PCGASMGetSubKSP(), PCGASMCreateSubdomains2D(), 1821 PCGASMSetSubdomains(), PCGASMGetSubmatrices() 1822 @*/ 1823 PetscErrorCode PCGASMGetSubdomains(PC pc,PetscInt *n,IS *iis[],IS *ois[]) 1824 { 1825 PC_GASM *osm; 1826 PetscErrorCode ierr; 1827 PetscBool match; 1828 PetscInt i; 1829 1830 PetscFunctionBegin; 1831 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1832 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1833 if (!match) SETERRQ2(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Incorrect object type: expected %s, got %s instead", PCGASM, ((PetscObject)pc)->type_name); 1834 osm = (PC_GASM*)pc->data; 1835 if (n) *n = osm->n; 1836 if (iis) { 1837 ierr = PetscMalloc1(osm->n, iis);CHKERRQ(ierr); 1838 } 1839 if (ois) { 1840 ierr = PetscMalloc1(osm->n, ois);CHKERRQ(ierr); 1841 } 1842 if (iis || ois) { 1843 for (i = 0; i < osm->n; ++i) { 1844 if (iis) (*iis)[i] = osm->iis[i]; 1845 if (ois) (*ois)[i] = osm->ois[i]; 1846 } 1847 } 1848 PetscFunctionReturn(0); 1849 } 1850 1851 /*@C 1852 PCGASMGetSubmatrices - Gets the local submatrices (for this processor 1853 only) for the additive Schwarz preconditioner. 1854 1855 Not Collective 1856 1857 Input Parameter: 1858 . pc - the preconditioner context 1859 1860 Output Parameters: 1861 + n - the number of matrices for this processor (default value = 1) 1862 - mat - the matrices 1863 1864 Notes: matrices returned by this routine have the same communicators as the index sets (IS) 1865 used to define subdomains in PCGASMSetSubdomains() 1866 Level: advanced 1867 1868 .keywords: PC, GASM, set, local, subdomains, additive Schwarz, block Jacobi 1869 1870 .seealso: PCGASMSetOverlap(), PCGASMGetSubKSP(), 1871 PCGASMCreateSubdomains2D(), PCGASMSetSubdomains(), PCGASMGetSubdomains() 1872 @*/ 1873 PetscErrorCode PCGASMGetSubmatrices(PC pc,PetscInt *n,Mat *mat[]) 1874 { 1875 PC_GASM *osm; 1876 PetscErrorCode ierr; 1877 PetscBool match; 1878 1879 PetscFunctionBegin; 1880 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1881 PetscValidIntPointer(n,2); 1882 if (mat) PetscValidPointer(mat,3); 1883 if (!pc->setupcalled) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must call after KSPSetUP() or PCSetUp()."); 1884 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1885 if (!match) SETERRQ2(PetscObjectComm((PetscObject)pc), PETSC_ERR_ARG_WRONG, "Expected %s, got %s instead", PCGASM, ((PetscObject)pc)->type_name); 1886 osm = (PC_GASM*)pc->data; 1887 if (n) *n = osm->n; 1888 if (mat) *mat = osm->pmat; 1889 PetscFunctionReturn(0); 1890 } 1891 1892 /*@ 1893 PCGASMSetUseDMSubdomains - Indicates whether to use DMCreateDomainDecomposition() to define the subdomains, whenever possible. 1894 Logically Collective 1895 1896 Input Parameter: 1897 + pc - the preconditioner 1898 - flg - boolean indicating whether to use subdomains defined by the DM 1899 1900 Options Database Key: 1901 . -pc_gasm_dm_subdomains -pc_gasm_overlap -pc_gasm_total_subdomains 1902 1903 Level: intermediate 1904 1905 Notes: 1906 PCGASMSetSubdomains(), PCGASMSetTotalSubdomains() or PCGASMSetOverlap() take precedence over PCGASMSetUseDMSubdomains(), 1907 so setting PCGASMSetSubdomains() with nontrivial subdomain ISs or any of PCGASMSetTotalSubdomains() and PCGASMSetOverlap() 1908 automatically turns the latter off. 1909 1910 .keywords: PC, ASM, DM, set, subdomains, additive Schwarz 1911 1912 .seealso: PCGASMGetUseDMSubdomains(), PCGASMSetSubdomains(), PCGASMSetOverlap() 1913 PCGASMCreateSubdomains2D() 1914 @*/ 1915 PetscErrorCode PCGASMSetUseDMSubdomains(PC pc,PetscBool flg) 1916 { 1917 PC_GASM *osm = (PC_GASM*)pc->data; 1918 PetscErrorCode ierr; 1919 PetscBool match; 1920 1921 PetscFunctionBegin; 1922 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1923 PetscValidLogicalCollectiveBool(pc,flg,2); 1924 if (pc->setupcalled) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for a setup PC."); 1925 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1926 if (match) { 1927 if (!osm->user_subdomains && osm->N == PETSC_DETERMINE && osm->overlap < 0) { 1928 osm->dm_subdomains = flg; 1929 } 1930 } 1931 PetscFunctionReturn(0); 1932 } 1933 1934 /*@ 1935 PCGASMGetUseDMSubdomains - Returns flag indicating whether to use DMCreateDomainDecomposition() to define the subdomains, whenever possible. 1936 Not Collective 1937 1938 Input Parameter: 1939 . pc - the preconditioner 1940 1941 Output Parameter: 1942 . flg - boolean indicating whether to use subdomains defined by the DM 1943 1944 Level: intermediate 1945 1946 .keywords: PC, ASM, DM, set, subdomains, additive Schwarz 1947 1948 .seealso: PCGASMSetUseDMSubdomains(), PCGASMSetOverlap() 1949 PCGASMCreateSubdomains2D() 1950 @*/ 1951 PetscErrorCode PCGASMGetUseDMSubdomains(PC pc,PetscBool* flg) 1952 { 1953 PC_GASM *osm = (PC_GASM*)pc->data; 1954 PetscErrorCode ierr; 1955 PetscBool match; 1956 1957 PetscFunctionBegin; 1958 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1959 PetscValidPointer(flg,2); 1960 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1961 if (match) { 1962 if (flg) *flg = osm->dm_subdomains; 1963 } 1964 PetscFunctionReturn(0); 1965 } 1966