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 local subdomains on all processors (set in PCGASMSetTotalSubdomains() or 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 PCGASMSetTotalSubdomains() or in PCSetUp_GASM()) 10 */ 11 #include <petsc-private/pcimpl.h> /*I "petscpc.h" I*/ 12 13 typedef struct { 14 PetscInt N,n,nmax; 15 PetscInt overlap; /* overlap requested by user */ 16 KSP *ksp; /* linear solvers for each block */ 17 Vec gx,gy; /* Merged work vectors */ 18 Vec *x,*y; /* Split work vectors; storage aliases pieces of storage of the above merged vectors. */ 19 VecScatter gorestriction; /* merged restriction to disjoint union of outer subdomains */ 20 VecScatter girestriction; /* merged restriction to disjoint union of inner subdomains */ 21 IS *ois; /* index sets that define the outer (conceptually, overlapping) subdomains */ 22 IS *iis; /* index sets that define the inner (conceptually, nonoverlapping) subdomains */ 23 Mat *pmat; /* subdomain block matrices */ 24 PCGASMType type; /* use reduced interpolation, restriction or both */ 25 PetscBool create_local; /* whether the autocreated subdomains are local or not. */ 26 PetscBool type_set; /* if user set this value (so won't change it for symmetric problems) */ 27 PetscBool same_subdomain_solvers; /* flag indicating whether all local solvers are same */ 28 PetscBool sort_indices; /* flag to sort subdomain indices */ 29 } PC_GASM; 30 31 #undef __FUNCT__ 32 #define __FUNCT__ "PCGASMSubdomainView_Private" 33 static PetscErrorCode PCGASMSubdomainView_Private(PC pc, PetscInt i, PetscViewer viewer) 34 { 35 PC_GASM *osm = (PC_GASM*)pc->data; 36 PetscInt j,nidx; 37 const PetscInt *idx; 38 PetscViewer sviewer; 39 char *cidx; 40 PetscErrorCode ierr; 41 42 PetscFunctionBegin; 43 if (i < 0 || i > osm->n) SETERRQ2(((PetscObject)viewer)->comm, PETSC_ERR_ARG_WRONG, "Invalid subdomain %D: must nonnegative and less than %D", i, osm->n); 44 /* Inner subdomains. */ 45 ierr = ISGetLocalSize(osm->iis[i], &nidx);CHKERRQ(ierr); 46 /* 47 No more than 15 characters per index plus a space. 48 PetscViewerStringSPrintf requires a string of size at least 2, so use (nidx+1) instead of nidx, 49 in case nidx == 0. That will take care of the space for the trailing '\0' as well. 50 For nidx == 0, the whole string 16 '\0'. 51 */ 52 ierr = PetscMalloc(sizeof(char)*(16*(nidx+1)+1), &cidx);CHKERRQ(ierr); 53 ierr = PetscViewerStringOpen(PETSC_COMM_SELF, cidx, 16*(nidx+1)+1, &sviewer);CHKERRQ(ierr); 54 ierr = ISGetIndices(osm->iis[i], &idx);CHKERRQ(ierr); 55 for (j = 0; j < nidx; ++j) { 56 ierr = PetscViewerStringSPrintf(sviewer, "%D ", idx[j]);CHKERRQ(ierr); 57 } 58 ierr = ISRestoreIndices(osm->iis[i],&idx);CHKERRQ(ierr); 59 ierr = PetscViewerDestroy(&sviewer);CHKERRQ(ierr); 60 ierr = PetscViewerASCIIPrintf(viewer, "Inner subdomain:\n");CHKERRQ(ierr); 61 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 62 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr); 63 ierr = PetscViewerASCIISynchronizedPrintf(viewer, "%s", cidx);CHKERRQ(ierr); 64 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 65 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr); 66 ierr = PetscViewerASCIIPrintf(viewer, "\n");CHKERRQ(ierr); 67 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 68 ierr = PetscFree(cidx);CHKERRQ(ierr); 69 /* Outer subdomains. */ 70 ierr = ISGetLocalSize(osm->ois[i], &nidx);CHKERRQ(ierr); 71 /* 72 No more than 15 characters per index plus a space. 73 PetscViewerStringSPrintf requires a string of size at least 2, so use (nidx+1) instead of nidx, 74 in case nidx == 0. That will take care of the space for the trailing '\0' as well. 75 For nidx == 0, the whole string 16 '\0'. 76 */ 77 ierr = PetscMalloc(sizeof(char)*(16*(nidx+1)+1), &cidx);CHKERRQ(ierr); 78 ierr = PetscViewerStringOpen(PETSC_COMM_SELF, cidx, 16*(nidx+1)+1, &sviewer);CHKERRQ(ierr); 79 ierr = ISGetIndices(osm->ois[i], &idx);CHKERRQ(ierr); 80 for (j = 0; j < nidx; ++j) { 81 ierr = PetscViewerStringSPrintf(sviewer,"%D ", idx[j]);CHKERRQ(ierr); 82 } 83 ierr = PetscViewerDestroy(&sviewer);CHKERRQ(ierr); 84 ierr = ISRestoreIndices(osm->ois[i],&idx);CHKERRQ(ierr); 85 ierr = PetscViewerASCIIPrintf(viewer, "Outer subdomain:\n");CHKERRQ(ierr); 86 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 87 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr); 88 ierr = PetscViewerASCIISynchronizedPrintf(viewer, "%s", cidx);CHKERRQ(ierr); 89 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 90 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr); 91 ierr = PetscViewerASCIIPrintf(viewer, "\n");CHKERRQ(ierr); 92 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 93 ierr = PetscFree(cidx);CHKERRQ(ierr); 94 95 PetscFunctionReturn(0); 96 } 97 98 #undef __FUNCT__ 99 #define __FUNCT__ "PCGASMPrintSubdomains" 100 static PetscErrorCode PCGASMPrintSubdomains(PC pc) 101 { 102 PC_GASM *osm = (PC_GASM*)pc->data; 103 const char *prefix; 104 char fname[PETSC_MAX_PATH_LEN+1]; 105 PetscInt i, l, d, count, gcount, *permutation, *numbering; 106 PetscBool found; 107 PetscViewer viewer, sviewer = PETSC_NULL; 108 PetscErrorCode ierr; 109 110 PetscFunctionBegin; 111 ierr = PetscMalloc2(osm->n, PetscInt, &permutation, osm->n, PetscInt, &numbering);CHKERRQ(ierr); 112 for (i = 0; i < osm->n; ++i) permutation[i] = i; 113 ierr = PetscObjectsGetGlobalNumbering(((PetscObject)pc)->comm, osm->n, (PetscObject*)osm->ois, &gcount, numbering);CHKERRQ(ierr); 114 ierr = PetscSortIntWithPermutation(osm->n, numbering, permutation);CHKERRQ(ierr); 115 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 116 ierr = PetscOptionsGetString(prefix,"-pc_gasm_print_subdomains",fname,PETSC_MAX_PATH_LEN,&found);CHKERRQ(ierr); 117 if (!found) { ierr = PetscStrcpy(fname,"stdout");CHKERRQ(ierr); }; 118 ierr = PetscViewerASCIIOpen(((PetscObject)pc)->comm,fname,&viewer);CHKERRQ(ierr); 119 /* 120 Make sure the viewer has a name. Otherwise this may cause a deadlock or other weird errors when creating a subcomm viewer: 121 the subcomm viewer will attempt to inherit the viewer's name, which, if not set, will be constructed collectively on the comm. 122 */ 123 ierr = PetscObjectName((PetscObject)viewer);CHKERRQ(ierr); 124 l = 0; 125 for (count = 0; count < gcount; ++count) { 126 /* Now let subdomains go one at a time in the global numbering order and print their subdomain/solver info. */ 127 if (l<osm->n){ 128 d = permutation[l]; /* d is the local number of the l-th smallest (in the global ordering) among the locally supported subdomains */ 129 if (numbering[d] == count) { 130 ierr = PetscViewerGetSubcomm(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 131 ierr = PCGASMSubdomainView_Private(pc,d,sviewer);CHKERRQ(ierr); 132 ierr = PetscViewerRestoreSubcomm(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 133 ++l; 134 } 135 } 136 ierr = MPI_Barrier(((PetscObject)pc)->comm);CHKERRQ(ierr); 137 } 138 ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); 139 ierr = PetscFree2(permutation,numbering);CHKERRQ(ierr); 140 PetscFunctionReturn(0); 141 } 142 143 144 #undef __FUNCT__ 145 #define __FUNCT__ "PCView_GASM" 146 static PetscErrorCode PCView_GASM(PC pc,PetscViewer viewer) 147 { 148 PC_GASM *osm = (PC_GASM*)pc->data; 149 const char *prefix; 150 PetscErrorCode ierr; 151 PetscMPIInt rank, size; 152 PetscInt i,bsz; 153 PetscBool iascii,view_subdomains=PETSC_FALSE; 154 PetscViewer sviewer; 155 PetscInt count, l, gcount, *numbering, *permutation; 156 char overlap[256] = "user-defined overlap"; 157 char gsubdomains[256] = "unknown total number of subdomains"; 158 char lsubdomains[256] = "unknown number of local subdomains"; 159 char msubdomains[256] = "unknown max number of local subdomains"; 160 PetscFunctionBegin; 161 ierr = MPI_Comm_size(((PetscObject)pc)->comm, &size);CHKERRQ(ierr); 162 ierr = MPI_Comm_rank(((PetscObject)pc)->comm, &rank);CHKERRQ(ierr); 163 164 165 ierr = PetscMalloc2(osm->n, PetscInt, &permutation, osm->n, PetscInt, &numbering);CHKERRQ(ierr); 166 for (i = 0; i < osm->n; ++i) permutation[i] = i; 167 ierr = PetscObjectsGetGlobalNumbering(((PetscObject)pc)->comm, osm->n, (PetscObject*)osm->ois, &gcount, numbering);CHKERRQ(ierr); 168 ierr = PetscSortIntWithPermutation(osm->n, numbering, permutation);CHKERRQ(ierr); 169 170 if (osm->overlap >= 0) { 171 ierr = PetscSNPrintf(overlap,sizeof(overlap),"requested amount of overlap = %D",osm->overlap);CHKERRQ(ierr); 172 } 173 ierr = PetscSNPrintf(gsubdomains, sizeof(gsubdomains), "total number of subdomains = %D",gcount);CHKERRQ(ierr); 174 if (osm->N > 0) { 175 ierr = PetscSNPrintf(lsubdomains, sizeof(gsubdomains), "number of local subdomains = %D",osm->N);CHKERRQ(ierr); 176 } 177 if (osm->nmax > 0){ 178 ierr = PetscSNPrintf(msubdomains,sizeof(msubdomains),"max number of local subdomains = %D",osm->nmax);CHKERRQ(ierr); 179 } 180 181 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 182 ierr = PetscOptionsGetBool(prefix,"-pc_gasm_view_subdomains",&view_subdomains,PETSC_NULL);CHKERRQ(ierr); 183 184 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 185 if (iascii) { 186 /* 187 Make sure the viewer has a name. Otherwise this may cause a deadlock when creating a subcomm viewer: 188 the subcomm viewer will attempt to inherit the viewer's name, which, if not set, will be constructed 189 collectively on the comm. 190 */ 191 ierr = PetscObjectName((PetscObject)viewer);CHKERRQ(ierr); 192 ierr = PetscViewerASCIIPrintf(viewer,"Generalized additive Schwarz:\n");CHKERRQ(ierr); 193 ierr = PetscViewerASCIIPrintf(viewer,"Restriction/interpolation type: %s\n",PCGASMTypes[osm->type]);CHKERRQ(ierr); 194 ierr = PetscViewerASCIIPrintf(viewer,"%s\n",overlap);CHKERRQ(ierr); 195 ierr = PetscViewerASCIIPrintf(viewer,"%s\n",gsubdomains);CHKERRQ(ierr); 196 ierr = PetscViewerASCIIPrintf(viewer,"%s\n",lsubdomains);CHKERRQ(ierr); 197 ierr = PetscViewerASCIIPrintf(viewer,"%s\n",msubdomains);CHKERRQ(ierr); 198 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr); 199 ierr = PetscViewerASCIISynchronizedPrintf(viewer,"[%d:%d] number of locally-supported subdomains = %D\n",(int)rank,(int)size,osm->n);CHKERRQ(ierr); 200 ierr = PetscViewerFlush(viewer);CHKERRQ(ierr); 201 ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr); 202 /* Cannot take advantage of osm->same_subdomain_solvers without a global numbering of subdomains. */ 203 ierr = PetscViewerASCIIPrintf(viewer,"Subdomain solver info is as follows:\n");CHKERRQ(ierr); 204 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 205 ierr = PetscViewerASCIIPrintf(viewer,"- - - - - - - - - - - - - - - - - -\n");CHKERRQ(ierr); 206 /* Make sure that everybody waits for the banner to be printed. */ 207 ierr = MPI_Barrier(((PetscObject)viewer)->comm);CHKERRQ(ierr); 208 /* Now let subdomains go one at a time in the global numbering order and print their subdomain/solver info. */ 209 l = 0; 210 for (count = 0; count < gcount; ++count) { 211 PetscMPIInt srank, ssize; 212 if (l<osm->n){ 213 PetscInt d = permutation[l]; /* d is the local number of the l-th smallest (in the global ordering) among the locally supported subdomains */ 214 if (numbering[d] == count) { 215 ierr = MPI_Comm_size(((PetscObject)osm->ois[d])->comm, &ssize);CHKERRQ(ierr); 216 ierr = MPI_Comm_rank(((PetscObject)osm->ois[d])->comm, &srank);CHKERRQ(ierr); 217 ierr = PetscViewerGetSubcomm(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 218 ierr = ISGetLocalSize(osm->ois[d],&bsz);CHKERRQ(ierr); 219 ierr = PetscViewerASCIISynchronizedAllow(sviewer,PETSC_TRUE);CHKERRQ(ierr); 220 ierr = PetscViewerASCIISynchronizedPrintf(sviewer,"[%D:%D] (subcomm [%D:%D]) local subdomain number %D, local size = %D\n",(int)rank,(int)size,(int)srank,(int)ssize,d,bsz);CHKERRQ(ierr); 221 ierr = PetscViewerFlush(sviewer);CHKERRQ(ierr); 222 ierr = PetscViewerASCIISynchronizedAllow(sviewer,PETSC_FALSE);CHKERRQ(ierr); 223 if (view_subdomains) { 224 ierr = PCGASMSubdomainView_Private(pc,d,sviewer);CHKERRQ(ierr); 225 } 226 if (!pc->setupcalled) { 227 PetscViewerASCIIPrintf(sviewer, "Solver not set up yet: PCSetUp() not yet called\n");CHKERRQ(ierr); 228 } 229 else { 230 ierr = KSPView(osm->ksp[d],sviewer);CHKERRQ(ierr); 231 } 232 ierr = PetscViewerASCIIPrintf(sviewer,"- - - - - - - - - - - - - - - - - -\n");CHKERRQ(ierr); 233 ierr = PetscViewerFlush(sviewer);CHKERRQ(ierr); 234 ierr = PetscViewerRestoreSubcomm(viewer,((PetscObject)osm->ois[d])->comm, &sviewer);CHKERRQ(ierr); 235 ++l; 236 } 237 } 238 ierr = MPI_Barrier(((PetscObject)pc)->comm);CHKERRQ(ierr); 239 } 240 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 241 } else { 242 SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_SUP,"Viewer type %s not supported for PCGASM",((PetscObject)viewer)->type_name); 243 } 244 ierr = PetscFree2(permutation,numbering);CHKERRQ(ierr); 245 PetscFunctionReturn(0); 246 } 247 248 249 250 251 252 #undef __FUNCT__ 253 #define __FUNCT__ "PCSetUp_GASM" 254 static PetscErrorCode PCSetUp_GASM(PC pc) 255 { 256 PC_GASM *osm = (PC_GASM*)pc->data; 257 PetscErrorCode ierr; 258 PetscBool symset,flg; 259 PetscInt i; 260 PetscMPIInt rank, size; 261 MatReuse scall = MAT_REUSE_MATRIX; 262 KSP ksp; 263 PC subpc; 264 const char *prefix,*pprefix; 265 Vec x,y; 266 PetscInt oni; /* Number of indices in the i-th local outer subdomain. */ 267 const PetscInt *oidxi; /* Indices from the i-th subdomain local outer subdomain. */ 268 PetscInt on; /* Number of indices in the disjoint union of local outer subdomains. */ 269 PetscInt *oidx; /* Indices in the disjoint union of local outer subdomains. */ 270 IS gois; /* Disjoint union the global indices of outer subdomains. */ 271 IS goid; /* Identity IS of the size of the disjoint union of outer subdomains. */ 272 PetscScalar *gxarray, *gyarray; 273 PetscInt gofirst; /* Start of locally-owned indices in the vectors -- osm->gx,osm->gy -- 274 over the disjoint union of outer subdomains. */ 275 DM *subdomain_dm = PETSC_NULL; 276 277 PetscFunctionBegin; 278 ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr); 279 ierr = MPI_Comm_rank(((PetscObject)pc)->comm,&rank);CHKERRQ(ierr); 280 if (!pc->setupcalled) { 281 282 if (!osm->type_set) { 283 ierr = MatIsSymmetricKnown(pc->pmat,&symset,&flg);CHKERRQ(ierr); 284 if (symset && flg) { osm->type = PC_GASM_BASIC; } 285 } 286 287 /* 288 If subdomains have been set, then the local number of subdomains, osm->n, is NOT PETSC_DECIDE and is at least 1. 289 The total number of subdomains, osm->N is not necessarily set, might be PETSC_DECIDE, and then will have to be calculated from osm->n. 290 */ 291 if (osm->n == PETSC_DECIDE) { 292 /* no subdomains given */ 293 /* try pc->dm first */ 294 if (pc->dm) { 295 char ddm_name[1024]; 296 DM ddm; 297 PetscBool flg; 298 PetscInt num_subdomains, d; 299 char **subdomain_names; 300 IS *inner_subdomain_is, *outer_subdomain_is; 301 /* Allow the user to request a decomposition DM by name */ 302 ierr = PetscStrncpy(ddm_name, "", 1024);CHKERRQ(ierr); 303 ierr = PetscOptionsString("-pc_gasm_decomposition","Name of the DM defining the decomposition", "PCSetDM",ddm_name,ddm_name,1024,&flg);CHKERRQ(ierr); 304 if (flg) { 305 ierr = DMCreateDomainDecompositionDM(pc->dm, ddm_name, &ddm);CHKERRQ(ierr); 306 if (!ddm) { 307 SETERRQ1(((PetscObject)pc)->comm, PETSC_ERR_ARG_WRONGSTATE, "Uknown DM decomposition name %s", ddm_name); 308 } 309 ierr = PetscInfo(pc,"Using decomposition DM defined using options database\n");CHKERRQ(ierr); 310 ierr = PCSetDM(pc,ddm);CHKERRQ(ierr); 311 } 312 ierr = DMCreateDomainDecomposition(pc->dm, &num_subdomains, &subdomain_names, &inner_subdomain_is, &outer_subdomain_is, &subdomain_dm);CHKERRQ(ierr); 313 if (num_subdomains) { 314 ierr = PCGASMSetSubdomains(pc, num_subdomains, inner_subdomain_is, outer_subdomain_is);CHKERRQ(ierr); 315 } 316 for (d = 0; d < num_subdomains; ++d) { 317 if (subdomain_names) {ierr = PetscFree(subdomain_names[d]);CHKERRQ(ierr);} 318 if (inner_subdomain_is) {ierr = ISDestroy(&inner_subdomain_is[d]);CHKERRQ(ierr);} 319 if (outer_subdomain_is) {ierr = ISDestroy(&outer_subdomain_is[d]);CHKERRQ(ierr);} 320 } 321 ierr = PetscFree(subdomain_names);CHKERRQ(ierr); 322 ierr = PetscFree(inner_subdomain_is);CHKERRQ(ierr); 323 ierr = PetscFree(outer_subdomain_is);CHKERRQ(ierr); 324 } 325 if (osm->n == PETSC_DECIDE) { /* still no subdomains; use one per processor */ 326 osm->nmax = osm->n = 1; 327 ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr); 328 osm->N = size; 329 } 330 } 331 if (!osm->iis){ 332 /* 333 The local number of subdomains was set just above, or in PCGASMSetTotalSubdomains(), or in PCGASMSetSubdomains(), 334 but the actual subdomains have not been supplied (in PCGASMSetSubdomains()). 335 We create the requisite number of inner subdomains on PETSC_COMM_SELF (for now). 336 */ 337 ierr = PCGASMCreateLocalSubdomains(pc->pmat,osm->overlap,osm->n,&osm->iis,&osm->ois);CHKERRQ(ierr); 338 } 339 if (osm->N == PETSC_DECIDE) { 340 struct {PetscInt max,sum;} inwork,outwork; 341 /* determine global number of subdomains and the max number of local subdomains */ 342 inwork.max = osm->n; 343 inwork.sum = osm->n; 344 ierr = MPI_Allreduce(&inwork,&outwork,1,MPIU_2INT,PetscMaxSum_Op,((PetscObject)pc)->comm);CHKERRQ(ierr); 345 osm->nmax = outwork.max; 346 osm->N = outwork.sum; 347 } 348 349 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 350 flg = PETSC_FALSE; 351 ierr = PetscOptionsGetBool(prefix,"-pc_gasm_print_subdomains",&flg,PETSC_NULL);CHKERRQ(ierr); 352 if (flg) { ierr = PCGASMPrintSubdomains(pc);CHKERRQ(ierr); } 353 354 if (osm->sort_indices) { 355 for (i=0; i<osm->n; i++) { 356 ierr = ISSort(osm->ois[i]);CHKERRQ(ierr); 357 ierr = ISSort(osm->iis[i]);CHKERRQ(ierr); 358 } 359 } 360 /* 361 Merge the ISs, create merged vectors and restrictions. 362 */ 363 /* Merge outer subdomain ISs and construct a restriction onto the disjoint union of local outer subdomains. */ 364 on = 0; 365 for (i=0; i<osm->n; i++) { 366 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 367 on += oni; 368 } 369 ierr = PetscMalloc(on*sizeof(PetscInt), &oidx);CHKERRQ(ierr); 370 on = 0; 371 for (i=0; i<osm->n; i++) { 372 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 373 ierr = ISGetIndices(osm->ois[i],&oidxi);CHKERRQ(ierr); 374 ierr = PetscMemcpy(oidx+on, oidxi, sizeof(PetscInt)*oni);CHKERRQ(ierr); 375 ierr = ISRestoreIndices(osm->ois[i], &oidxi);CHKERRQ(ierr); 376 on += oni; 377 } 378 ierr = ISCreateGeneral(((PetscObject)(pc))->comm, on, oidx, PETSC_OWN_POINTER, &gois);CHKERRQ(ierr); 379 ierr = MatGetVecs(pc->pmat,&x,&y);CHKERRQ(ierr); 380 ierr = VecCreateMPI(((PetscObject)pc)->comm, on, PETSC_DECIDE, &osm->gx);CHKERRQ(ierr); 381 ierr = VecDuplicate(osm->gx,&osm->gy);CHKERRQ(ierr); 382 ierr = VecGetOwnershipRange(osm->gx, &gofirst, PETSC_NULL);CHKERRQ(ierr); 383 ierr = ISCreateStride(((PetscObject)pc)->comm,on,gofirst,1, &goid);CHKERRQ(ierr); 384 ierr = VecScatterCreate(x,gois,osm->gx,goid, &(osm->gorestriction));CHKERRQ(ierr); 385 ierr = VecDestroy(&x);CHKERRQ(ierr); 386 ierr = ISDestroy(&gois);CHKERRQ(ierr); 387 /* Merge inner subdomain ISs and construct a restriction onto the disjoint union of local inner subdomains. */ 388 { PetscInt ini; /* Number of indices the i-th a local inner subdomain. */ 389 PetscInt in; /* Number of indices in the disjoint uniont of local inner subdomains. */ 390 PetscInt *iidx; /* Global indices in the merged local inner subdomain. */ 391 PetscInt *ioidx; /* Global indices of the disjoint union of inner subdomains within the disjoint union of outer subdomains. */ 392 IS giis; /* IS for the disjoint union of inner subdomains. */ 393 IS giois; /* IS for the disjoint union of inner subdomains within the disjoint union of outer subdomains. */ 394 /**/ 395 in = 0; 396 for (i=0; i<osm->n; i++) { 397 ierr = ISGetLocalSize(osm->iis[i],&ini);CHKERRQ(ierr); 398 in += ini; 399 } 400 ierr = PetscMalloc(in*sizeof(PetscInt), &iidx);CHKERRQ(ierr); 401 ierr = PetscMalloc(in*sizeof(PetscInt), &ioidx);CHKERRQ(ierr); 402 ierr = VecGetOwnershipRange(osm->gx,&gofirst, PETSC_NULL);CHKERRQ(ierr); 403 in = 0; 404 on = 0; 405 for (i=0; i<osm->n; i++) { 406 const PetscInt *iidxi; /* Global indices of the i-th local inner subdomain. */ 407 ISLocalToGlobalMapping ltogi; /* Map from global to local indices of the i-th outer local subdomain. */ 408 PetscInt *ioidxi; /* Local indices of the i-th local inner subdomain within the local outer subdomain. */ 409 PetscInt ioni; /* Number of indices in ioidxi; if ioni != ini the inner subdomain is not a subdomain of the outer subdomain (error). */ 410 PetscInt k; 411 ierr = ISGetLocalSize(osm->iis[i],&ini);CHKERRQ(ierr); 412 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 413 ierr = ISGetIndices(osm->iis[i],&iidxi);CHKERRQ(ierr); 414 ierr = PetscMemcpy(iidx+in, iidxi, sizeof(PetscInt)*ini);CHKERRQ(ierr); 415 ierr = ISLocalToGlobalMappingCreateIS(osm->ois[i],<ogi);CHKERRQ(ierr); 416 ioidxi = ioidx+in; 417 ierr = ISGlobalToLocalMappingApply(ltogi,IS_GTOLM_DROP,ini,iidxi,&ioni,ioidxi);CHKERRQ(ierr); 418 ierr = ISLocalToGlobalMappingDestroy(<ogi);CHKERRQ(ierr); 419 ierr = ISRestoreIndices(osm->iis[i], &iidxi);CHKERRQ(ierr); 420 if (ioni != ini) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Inner subdomain %D contains %D indices outside of its outer subdomain", i, ini - ioni); 421 for (k = 0; k < ini; ++k) { 422 ioidxi[k] += gofirst+on; 423 } 424 in += ini; 425 on += oni; 426 } 427 ierr = ISCreateGeneral(((PetscObject)pc)->comm, in, iidx, PETSC_OWN_POINTER, &giis);CHKERRQ(ierr); 428 ierr = ISCreateGeneral(((PetscObject)pc)->comm, in, ioidx, PETSC_OWN_POINTER, &giois);CHKERRQ(ierr); 429 ierr = VecScatterCreate(y,giis,osm->gy,giois,&osm->girestriction);CHKERRQ(ierr); 430 ierr = VecDestroy(&y);CHKERRQ(ierr); 431 ierr = ISDestroy(&giis);CHKERRQ(ierr); 432 ierr = ISDestroy(&giois);CHKERRQ(ierr); 433 } 434 ierr = ISDestroy(&goid);CHKERRQ(ierr); 435 /* Create the subdomain work vectors. */ 436 ierr = PetscMalloc(osm->n*sizeof(Vec),&osm->x);CHKERRQ(ierr); 437 ierr = PetscMalloc(osm->n*sizeof(Vec),&osm->y);CHKERRQ(ierr); 438 ierr = VecGetArray(osm->gx, &gxarray);CHKERRQ(ierr); 439 ierr = VecGetArray(osm->gy, &gyarray);CHKERRQ(ierr); 440 for (i=0, on=0; i<osm->n; ++i, on += oni) { 441 PetscInt oNi; 442 ierr = ISGetLocalSize(osm->ois[i],&oni);CHKERRQ(ierr); 443 ierr = ISGetSize(osm->ois[i],&oNi);CHKERRQ(ierr); 444 ierr = VecCreateMPIWithArray(((PetscObject)(osm->ois[i]))->comm,1,oni,oNi,gxarray+on,&osm->x[i]);CHKERRQ(ierr); 445 ierr = VecCreateMPIWithArray(((PetscObject)(osm->ois[i]))->comm,1,oni,oNi,gyarray+on,&osm->y[i]);CHKERRQ(ierr); 446 } 447 ierr = VecRestoreArray(osm->gx, &gxarray);CHKERRQ(ierr); 448 ierr = VecRestoreArray(osm->gy, &gyarray);CHKERRQ(ierr); 449 /* Create the local solvers */ 450 ierr = PetscMalloc(osm->n*sizeof(KSP *),&osm->ksp);CHKERRQ(ierr); 451 for (i=0; i<osm->n; i++) { /* KSPs are local */ 452 ierr = KSPCreate(((PetscObject)(osm->ois[i]))->comm,&ksp);CHKERRQ(ierr); 453 ierr = PetscLogObjectParent(pc,ksp);CHKERRQ(ierr); 454 ierr = PetscObjectIncrementTabLevel((PetscObject)ksp,(PetscObject)pc,1);CHKERRQ(ierr); 455 ierr = KSPSetType(ksp,KSPPREONLY);CHKERRQ(ierr); 456 ierr = KSPGetPC(ksp,&subpc);CHKERRQ(ierr); 457 ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr); 458 ierr = KSPSetOptionsPrefix(ksp,prefix);CHKERRQ(ierr); 459 ierr = KSPAppendOptionsPrefix(ksp,"sub_");CHKERRQ(ierr); 460 osm->ksp[i] = ksp; 461 } 462 scall = MAT_INITIAL_MATRIX; 463 464 }/*if (!pc->setupcalled)*/ 465 else { 466 /* 467 Destroy the blocks from the previous iteration 468 */ 469 if (pc->flag == DIFFERENT_NONZERO_PATTERN) { 470 ierr = MatDestroyMatrices(osm->n,&osm->pmat);CHKERRQ(ierr); 471 scall = MAT_INITIAL_MATRIX; 472 } 473 } 474 475 /* 476 Extract out the submatrices. 477 */ 478 if (size > 1) { 479 ierr = MatGetSubMatricesParallel(pc->pmat,osm->n,osm->ois, osm->ois,scall,&osm->pmat);CHKERRQ(ierr); 480 } 481 else { 482 ierr = MatGetSubMatrices(pc->pmat,osm->n,osm->ois, osm->ois,scall,&osm->pmat);CHKERRQ(ierr); 483 } 484 if (scall == MAT_INITIAL_MATRIX) { 485 ierr = PetscObjectGetOptionsPrefix((PetscObject)pc->pmat,&pprefix);CHKERRQ(ierr); 486 for (i=0; i<osm->n; i++) { 487 ierr = PetscLogObjectParent(pc,osm->pmat[i]);CHKERRQ(ierr); 488 ierr = PetscObjectSetOptionsPrefix((PetscObject)osm->pmat[i],pprefix);CHKERRQ(ierr); 489 } 490 } 491 492 /* Return control to the user so that the submatrices can be modified (e.g., to apply 493 different boundary conditions for the submatrices than for the global problem) */ 494 ierr = PCModifySubMatrices(pc,osm->n,osm->ois,osm->ois,osm->pmat,pc->modifysubmatricesP);CHKERRQ(ierr); 495 496 /* 497 Loop over submatrices putting them into local ksps 498 */ 499 for (i=0; i<osm->n; i++) { 500 ierr = KSPSetOperators(osm->ksp[i],osm->pmat[i],osm->pmat[i],pc->flag);CHKERRQ(ierr); 501 if (!pc->setupcalled) { 502 ierr = KSPSetFromOptions(osm->ksp[i]);CHKERRQ(ierr); 503 } 504 } 505 506 PetscFunctionReturn(0); 507 } 508 509 #undef __FUNCT__ 510 #define __FUNCT__ "PCSetUpOnBlocks_GASM" 511 static PetscErrorCode PCSetUpOnBlocks_GASM(PC pc) 512 { 513 PC_GASM *osm = (PC_GASM*)pc->data; 514 PetscErrorCode ierr; 515 PetscInt i; 516 517 PetscFunctionBegin; 518 for (i=0; i<osm->n; i++) { 519 ierr = KSPSetUp(osm->ksp[i]);CHKERRQ(ierr); 520 } 521 PetscFunctionReturn(0); 522 } 523 524 #undef __FUNCT__ 525 #define __FUNCT__ "PCApply_GASM" 526 static PetscErrorCode PCApply_GASM(PC pc,Vec x,Vec y) 527 { 528 PC_GASM *osm = (PC_GASM*)pc->data; 529 PetscErrorCode ierr; 530 PetscInt i; 531 ScatterMode forward = SCATTER_FORWARD,reverse = SCATTER_REVERSE; 532 533 PetscFunctionBegin; 534 /* 535 Support for limiting the restriction or interpolation only to the inner 536 subdomain values (leaving the other values 0). 537 */ 538 if (!(osm->type & PC_GASM_RESTRICT)) { 539 /* have to zero the work RHS since scatter may leave some slots empty */ 540 ierr = VecZeroEntries(osm->gx);CHKERRQ(ierr); 541 ierr = VecScatterBegin(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 542 } 543 else { 544 ierr = VecScatterBegin(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 545 } 546 ierr = VecZeroEntries(osm->gy);CHKERRQ(ierr); 547 if (!(osm->type & PC_GASM_RESTRICT)) { 548 ierr = VecScatterEnd(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 549 } 550 else { 551 ierr = VecScatterEnd(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 552 } 553 /* do the subdomain solves */ 554 for (i=0; i<osm->n; ++i) { 555 ierr = KSPSolve(osm->ksp[i],osm->x[i],osm->y[i]);CHKERRQ(ierr); 556 } 557 ierr = VecZeroEntries(y);CHKERRQ(ierr); 558 if (!(osm->type & PC_GASM_INTERPOLATE)) { 559 ierr = VecScatterBegin(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 560 ierr = VecScatterEnd(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); PetscFunctionReturn(0); 561 } 562 else { 563 ierr = VecScatterBegin(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 564 ierr = VecScatterEnd(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); PetscFunctionReturn(0); 565 } 566 } 567 568 #undef __FUNCT__ 569 #define __FUNCT__ "PCApplyTranspose_GASM" 570 static PetscErrorCode PCApplyTranspose_GASM(PC pc,Vec x,Vec y) 571 { 572 PC_GASM *osm = (PC_GASM*)pc->data; 573 PetscErrorCode ierr; 574 PetscInt i; 575 ScatterMode forward = SCATTER_FORWARD,reverse = SCATTER_REVERSE; 576 577 PetscFunctionBegin; 578 /* 579 Support for limiting the restriction or interpolation to only local 580 subdomain values (leaving the other values 0). 581 582 Note: these are reversed from the PCApply_GASM() because we are applying the 583 transpose of the three terms 584 */ 585 if (!(osm->type & PC_GASM_INTERPOLATE)) { 586 /* have to zero the work RHS since scatter may leave some slots empty */ 587 ierr = VecZeroEntries(osm->gx);CHKERRQ(ierr); 588 ierr = VecScatterBegin(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 589 } 590 else { 591 ierr = VecScatterBegin(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 592 } 593 ierr = VecZeroEntries(osm->gy);CHKERRQ(ierr); 594 if (!(osm->type & PC_GASM_INTERPOLATE)) { 595 ierr = VecScatterEnd(osm->girestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 596 } 597 else { 598 ierr = VecScatterEnd(osm->gorestriction,x,osm->gx,INSERT_VALUES,forward);CHKERRQ(ierr); 599 } 600 /* do the local solves */ 601 for (i=0; i<osm->n; ++i) { /* Note that the solves are local, so we can go to osm->n, rather than osm->nmax. */ 602 ierr = KSPSolveTranspose(osm->ksp[i],osm->x[i],osm->y[i]);CHKERRQ(ierr); 603 } 604 ierr = VecZeroEntries(y);CHKERRQ(ierr); 605 if (!(osm->type & PC_GASM_RESTRICT)) { 606 ierr = VecScatterBegin(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 607 ierr = VecScatterEnd(osm->girestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 608 } 609 else { 610 ierr = VecScatterBegin(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 611 ierr = VecScatterEnd(osm->gorestriction,osm->gy,y,ADD_VALUES,reverse);CHKERRQ(ierr); 612 } 613 614 PetscFunctionReturn(0); 615 } 616 617 #undef __FUNCT__ 618 #define __FUNCT__ "PCReset_GASM" 619 static PetscErrorCode PCReset_GASM(PC pc) 620 { 621 PC_GASM *osm = (PC_GASM*)pc->data; 622 PetscErrorCode ierr; 623 PetscInt i; 624 625 PetscFunctionBegin; 626 if (osm->ksp) { 627 for (i=0; i<osm->n; i++) { 628 ierr = KSPReset(osm->ksp[i]);CHKERRQ(ierr); 629 } 630 } 631 if (osm->pmat) { 632 if (osm->n > 0) { 633 ierr = MatDestroyMatrices(osm->n,&osm->pmat);CHKERRQ(ierr); 634 } 635 } 636 if (osm->x) { 637 for (i=0; i<osm->n; i++) { 638 ierr = VecDestroy(&osm->x[i]);CHKERRQ(ierr); 639 ierr = VecDestroy(&osm->y[i]);CHKERRQ(ierr); 640 } 641 } 642 ierr = VecDestroy(&osm->gx);CHKERRQ(ierr); 643 ierr = VecDestroy(&osm->gy);CHKERRQ(ierr); 644 645 ierr = VecScatterDestroy(&osm->gorestriction);CHKERRQ(ierr); 646 ierr = VecScatterDestroy(&osm->girestriction);CHKERRQ(ierr); 647 ierr = PCGASMDestroySubdomains(osm->n,osm->ois,osm->iis);CHKERRQ(ierr); 648 osm->ois = 0; 649 osm->iis = 0; 650 PetscFunctionReturn(0); 651 } 652 653 #undef __FUNCT__ 654 #define __FUNCT__ "PCDestroy_GASM" 655 static PetscErrorCode PCDestroy_GASM(PC pc) 656 { 657 PC_GASM *osm = (PC_GASM*)pc->data; 658 PetscErrorCode ierr; 659 PetscInt i; 660 661 PetscFunctionBegin; 662 ierr = PCReset_GASM(pc);CHKERRQ(ierr); 663 if (osm->ksp) { 664 for (i=0; i<osm->n; i++) { 665 ierr = KSPDestroy(&osm->ksp[i]);CHKERRQ(ierr); 666 } 667 ierr = PetscFree(osm->ksp);CHKERRQ(ierr); 668 } 669 ierr = PetscFree(osm->x);CHKERRQ(ierr); 670 ierr = PetscFree(osm->y);CHKERRQ(ierr); 671 ierr = PetscFree(pc->data);CHKERRQ(ierr); 672 PetscFunctionReturn(0); 673 } 674 675 #undef __FUNCT__ 676 #define __FUNCT__ "PCSetFromOptions_GASM" 677 static PetscErrorCode PCSetFromOptions_GASM(PC pc) { 678 PC_GASM *osm = (PC_GASM*)pc->data; 679 PetscErrorCode ierr; 680 PetscInt blocks,ovl; 681 PetscBool symset,flg; 682 PCGASMType gasmtype; 683 684 PetscFunctionBegin; 685 /* set the type to symmetric if matrix is symmetric */ 686 if (!osm->type_set && pc->pmat) { 687 ierr = MatIsSymmetricKnown(pc->pmat,&symset,&flg);CHKERRQ(ierr); 688 if (symset && flg) { osm->type = PC_GASM_BASIC; } 689 } 690 ierr = PetscOptionsHead("Generalized additive Schwarz options");CHKERRQ(ierr); 691 ierr = PetscOptionsInt("-pc_gasm_total_subdomains","Total number of subdomains across communicator","PCGASMSetTotalSubdomains",osm->n,&blocks,&flg);CHKERRQ(ierr); 692 osm->create_local = PETSC_TRUE; 693 ierr = PetscOptionsBool("-pc_gasm_subdomains_create_local","Whether to make autocreated subdomains local (true by default)","PCGASMSetTotalSubdomains",osm->create_local,&osm->create_local,&flg);CHKERRQ(ierr); 694 if (!osm->create_local) SETERRQ(((PetscObject)pc)->comm, PETSC_ERR_SUP, "No support for autocreation of nonlocal subdomains yet."); 695 696 if (flg) {ierr = PCGASMSetTotalSubdomains(pc,blocks,osm->create_local);CHKERRQ(ierr); } 697 ierr = PetscOptionsInt("-pc_gasm_overlap","Number of overlapping degrees of freedom","PCGASMSetOverlap",osm->overlap,&ovl,&flg);CHKERRQ(ierr); 698 if (flg) {ierr = PCGASMSetOverlap(pc,ovl);CHKERRQ(ierr); } 699 flg = PETSC_FALSE; 700 ierr = PetscOptionsEnum("-pc_gasm_type","Type of restriction/extension","PCGASMSetType",PCGASMTypes,(PetscEnum)osm->type,(PetscEnum*)&gasmtype,&flg);CHKERRQ(ierr); 701 if (flg) {ierr = PCGASMSetType(pc,gasmtype);CHKERRQ(ierr); } 702 ierr = PetscOptionsTail();CHKERRQ(ierr); 703 PetscFunctionReturn(0); 704 } 705 706 /*------------------------------------------------------------------------------------*/ 707 708 EXTERN_C_BEGIN 709 #undef __FUNCT__ 710 #define __FUNCT__ "PCGASMSetSubdomains_GASM" 711 PetscErrorCode PCGASMSetSubdomains_GASM(PC pc,PetscInt n,IS iis[],IS ois[]) 712 { 713 PC_GASM *osm = (PC_GASM*)pc->data; 714 PetscErrorCode ierr; 715 PetscInt i; 716 717 PetscFunctionBegin; 718 if (n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Each process must have 1 or more subdomains, n = %D",n); 719 if (pc->setupcalled && (n != osm->n || iis || ois)) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONGSTATE,"PCGASMSetSubdomains() should be called before calling PCSetUp()."); 720 721 if (!pc->setupcalled) { 722 osm->n = n; 723 osm->ois = 0; 724 osm->iis = 0; 725 if (ois) { 726 for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)ois[i]);CHKERRQ(ierr);} 727 } 728 if (iis) { 729 for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)iis[i]);CHKERRQ(ierr);} 730 } 731 ierr = PCGASMDestroySubdomains(osm->n,osm->iis,osm->ois);CHKERRQ(ierr); 732 if (ois) { 733 ierr = PetscMalloc(n*sizeof(IS),&osm->ois);CHKERRQ(ierr); 734 for (i=0; i<n; i++) { osm->ois[i] = ois[i]; } 735 /* Flag indicating that the user has set outer subdomains, so PCGASM should not increase their size. */ 736 osm->overlap = -1; 737 if (!iis) { 738 ierr = PetscMalloc(n*sizeof(IS),&osm->iis);CHKERRQ(ierr); 739 for (i=0; i<n; i++) { 740 for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)ois[i]);CHKERRQ(ierr);} 741 osm->iis[i] = ois[i]; 742 } 743 } 744 } 745 if (iis) { 746 ierr = PetscMalloc(n*sizeof(IS),&osm->iis);CHKERRQ(ierr); 747 for (i=0; i<n; i++) { osm->iis[i] = iis[i]; } 748 if (!ois) { 749 ierr = PetscMalloc(n*sizeof(IS),&osm->ois);CHKERRQ(ierr); 750 for (i=0; i<n; i++) { 751 for (i=0; i<n; i++) { 752 ierr = PetscObjectReference((PetscObject)iis[i]);CHKERRQ(ierr); 753 osm->ois[i] = iis[i]; 754 } 755 } 756 if (osm->overlap > 0) { 757 /* Extend the "overlapping" regions by a number of steps */ 758 ierr = MatIncreaseOverlap(pc->pmat,osm->n,osm->ois,osm->overlap);CHKERRQ(ierr); 759 } 760 } 761 } 762 } 763 PetscFunctionReturn(0); 764 } 765 EXTERN_C_END 766 767 EXTERN_C_BEGIN 768 #undef __FUNCT__ 769 #define __FUNCT__ "PCGASMSetTotalSubdomains_GASM" 770 PetscErrorCode PCGASMSetTotalSubdomains_GASM(PC pc,PetscInt N, PetscBool create_local) { 771 PC_GASM *osm = (PC_GASM*)pc->data; 772 PetscErrorCode ierr; 773 PetscMPIInt rank,size; 774 PetscInt n; 775 PetscInt Nmin, Nmax; 776 PetscFunctionBegin; 777 if (!create_local) SETERRQ(((PetscObject)pc)->comm, PETSC_ERR_SUP, "No suppor for autocreation of nonlocal subdomains."); 778 if (N < 1) SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Total number of subdomains must be > 0, N = %D",N); 779 ierr = MPI_Allreduce(&N,&Nmin,1,MPIU_INT,MPIU_MIN,((PetscObject)pc)->comm);CHKERRQ(ierr); 780 ierr = MPI_Allreduce(&N,&Nmax,1,MPIU_INT,MPIU_MAX,((PetscObject)pc)->comm);CHKERRQ(ierr); 781 if (Nmin != Nmax) 782 SETERRQ2(((PetscObject)pc)->comm, PETSC_ERR_ARG_WRONG, "All processors must use the same number of subdomains. min(N) = %D != %D = max(N)", Nmin, Nmax); 783 784 osm->create_local = create_local; 785 /* 786 Split the subdomains equally among all processors 787 */ 788 ierr = MPI_Comm_rank(((PetscObject)pc)->comm,&rank);CHKERRQ(ierr); 789 ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr); 790 n = N/size + ((N % size) > rank); 791 if (!n) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Process %d must have at least one subdomain: total processors %d total blocks %D",(int)rank,(int)size,N); 792 if (pc->setupcalled && n != osm->n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"PCGASMSetTotalSubdomains() should be called before PCSetUp()."); 793 if (!pc->setupcalled) { 794 ierr = PCGASMDestroySubdomains(osm->n,osm->iis,osm->ois);CHKERRQ(ierr); 795 osm->N = N; 796 osm->n = n; 797 osm->nmax = N/size + ((N%size)?1:0); 798 osm->ois = 0; 799 osm->iis = 0; 800 } 801 PetscFunctionReturn(0); 802 } 803 EXTERN_C_END 804 805 EXTERN_C_BEGIN 806 #undef __FUNCT__ 807 #define __FUNCT__ "PCGASMSetOverlap_GASM" 808 PetscErrorCode PCGASMSetOverlap_GASM(PC pc,PetscInt ovl) 809 { 810 PC_GASM *osm = (PC_GASM*)pc->data; 811 812 PetscFunctionBegin; 813 if (ovl < 0) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Negative overlap value requested"); 814 if (pc->setupcalled && ovl != osm->overlap) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONGSTATE,"PCGASMSetOverlap() should be called before PCSetUp()."); 815 if (!pc->setupcalled) { 816 osm->overlap = ovl; 817 } 818 PetscFunctionReturn(0); 819 } 820 EXTERN_C_END 821 822 EXTERN_C_BEGIN 823 #undef __FUNCT__ 824 #define __FUNCT__ "PCGASMSetType_GASM" 825 PetscErrorCode PCGASMSetType_GASM(PC pc,PCGASMType type) 826 { 827 PC_GASM *osm = (PC_GASM*)pc->data; 828 829 PetscFunctionBegin; 830 osm->type = type; 831 osm->type_set = PETSC_TRUE; 832 PetscFunctionReturn(0); 833 } 834 EXTERN_C_END 835 836 EXTERN_C_BEGIN 837 #undef __FUNCT__ 838 #define __FUNCT__ "PCGASMSetSortIndices_GASM" 839 PetscErrorCode PCGASMSetSortIndices_GASM(PC pc,PetscBool doSort) 840 { 841 PC_GASM *osm = (PC_GASM*)pc->data; 842 843 PetscFunctionBegin; 844 osm->sort_indices = doSort; 845 PetscFunctionReturn(0); 846 } 847 EXTERN_C_END 848 849 EXTERN_C_BEGIN 850 #undef __FUNCT__ 851 #define __FUNCT__ "PCGASMGetSubKSP_GASM" 852 /* 853 FIX: This routine might need to be modified once multiple ranks per subdomain are allowed. 854 In particular, it would upset the global subdomain number calculation. 855 */ 856 PetscErrorCode PCGASMGetSubKSP_GASM(PC pc,PetscInt *n,PetscInt *first,KSP **ksp) 857 { 858 PC_GASM *osm = (PC_GASM*)pc->data; 859 PetscErrorCode ierr; 860 861 PetscFunctionBegin; 862 if (osm->n < 1) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ORDER,"Need to call PCSetUP() on PC (or KSPSetUp() on the outer KSP object) before calling here"); 863 864 if (n) { 865 *n = osm->n; 866 } 867 if (first) { 868 ierr = MPI_Scan(&osm->n,first,1,MPIU_INT,MPI_SUM,((PetscObject)pc)->comm);CHKERRQ(ierr); 869 *first -= osm->n; 870 } 871 if (ksp) { 872 /* Assume that local solves are now different; not necessarily 873 true, though! This flag is used only for PCView_GASM() */ 874 *ksp = osm->ksp; 875 osm->same_subdomain_solvers = PETSC_FALSE; 876 } 877 PetscFunctionReturn(0); 878 }/* PCGASMGetSubKSP_GASM() */ 879 EXTERN_C_END 880 881 882 #undef __FUNCT__ 883 #define __FUNCT__ "PCGASMSetSubdomains" 884 /*@C 885 PCGASMSetSubdomains - Sets the subdomains for this processor 886 for the additive Schwarz preconditioner. 887 888 Collective on PC 889 890 Input Parameters: 891 + pc - the preconditioner context 892 . n - the number of subdomains for this processor 893 . iis - the index sets that define this processor's local inner subdomains 894 (or PETSC_NULL for PETSc to determine subdomains) 895 - ois- the index sets that define this processor's local outer subdomains 896 (or PETSC_NULL to use the same as iis) 897 898 Notes: 899 The IS indices use the parallel, global numbering of the vector entries. 900 Inner subdomains are those where the correction is applied. 901 Outer subdomains are those where the residual necessary to obtain the 902 corrections is obtained (see PCGASMType for the use of inner/outer subdomains). 903 Both inner and outer subdomains can extend over several processors. 904 This processor's portion of a subdomain is known as a local subdomain. 905 906 By default the GASM preconditioner uses 1 (local) subdomain per processor. 907 Use PCGASMSetTotalSubdomains() to set the total number of subdomains across 908 all processors that PCGASM will create automatically, and to specify whether 909 they should be local or not. 910 911 912 Level: advanced 913 914 .keywords: PC, GASM, set, subdomains, additive Schwarz 915 916 .seealso: PCGASMSetTotalSubdomains(), PCGASMSetOverlap(), PCGASMGetSubKSP(), 917 PCGASMCreateSubdomains2D(), PCGASMGetSubdomains() 918 @*/ 919 PetscErrorCode PCGASMSetSubdomains(PC pc,PetscInt n,IS iis[],IS ois[]) 920 { 921 PetscErrorCode ierr; 922 923 PetscFunctionBegin; 924 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 925 ierr = PetscTryMethod(pc,"PCGASMSetSubdomains_C",(PC,PetscInt,IS[],IS[]),(pc,n,iis,ois));CHKERRQ(ierr); 926 PetscFunctionReturn(0); 927 } 928 929 #undef __FUNCT__ 930 #define __FUNCT__ "PCGASMSetTotalSubdomains" 931 /*@C 932 PCGASMSetTotalSubdomains - Sets the total number of subdomains to use in the generalized additive 933 Schwarz preconditioner. The number of subdomains is cumulative across all processors in pc's 934 communicator. Either all or no processors in the PC communicator must call this routine with 935 the same N. The subdomains will be created automatically during PCSetUp(). 936 937 Collective on PC 938 939 Input Parameters: 940 + pc - the preconditioner context 941 . N - the total number of subdomains cumulative across all processors 942 - create_local - whether the subdomains to be created are to be local 943 944 Options Database Key: 945 To set the total number of subdomains and let PCGASM autocreate them, rather than specify the index sets, use the following options: 946 + -pc_gasm_total_subdomains <n> - sets the total number of subdomains to be autocreated by PCGASM 947 - -pc_gasm_subdomains_create_local <true|false> - whether autocreated subdomains should be local or not (default is true) 948 949 By default the GASM preconditioner uses 1 subdomain per processor. 950 951 952 Use PCGASMSetSubdomains() to set subdomains explicitly or to set different numbers 953 of subdomains per processor. 954 955 Level: advanced 956 957 .keywords: PC, GASM, set, total, global, subdomains, additive Schwarz 958 959 .seealso: PCGASMSetSubdomains(), PCGASMSetOverlap(), PCGASMGetSubKSP(), 960 PCGASMCreateSubdomains2D() 961 @*/ 962 PetscErrorCode PCGASMSetTotalSubdomains(PC pc,PetscInt N, PetscBool create_local) 963 { 964 PetscErrorCode ierr; 965 966 PetscFunctionBegin; 967 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 968 ierr = PetscTryMethod(pc,"PCGASMSetTotalSubdomains_C",(PC,PetscInt,PetscBool),(pc,N,create_local));CHKERRQ(ierr); 969 PetscFunctionReturn(0); 970 } 971 972 #undef __FUNCT__ 973 #define __FUNCT__ "PCGASMSetOverlap" 974 /*@ 975 PCGASMSetOverlap - Sets the overlap between a pair of subdomains for the 976 additive Schwarz preconditioner. Either all or no processors in the 977 PC communicator must call this routine. 978 979 Logically Collective on PC 980 981 Input Parameters: 982 + pc - the preconditioner context 983 - ovl - the amount of overlap between subdomains (ovl >= 0, default value = 1) 984 985 Options Database Key: 986 . -pc_gasm_overlap <overlap> - Sets overlap 987 988 Notes: 989 By default the GASM preconditioner uses 1 subdomain per processor. To use 990 multiple subdomain per perocessor, see PCGASMSetTotalSubdomains() or 991 PCGASMSetSubdomains() (and the option -pc_gasm_total_subdomains <n>). 992 993 The overlap defaults to 1, so if one desires that no additional 994 overlap be computed beyond what may have been set with a call to 995 PCGASMSetTotalSubdomains() or PCGASMSetSubdomains(), then ovl 996 must be set to be 0. In particular, if one does not explicitly set 997 the subdomains in application code, then all overlap would be computed 998 internally by PETSc, and using an overlap of 0 would result in an GASM 999 variant that is equivalent to the block Jacobi preconditioner. 1000 1001 Note that one can define initial index sets with any overlap via 1002 PCGASMSetSubdomains(); the routine PCGASMSetOverlap() merely allows 1003 PETSc to extend that overlap further, if desired. 1004 1005 Level: intermediate 1006 1007 .keywords: PC, GASM, set, overlap 1008 1009 .seealso: PCGASMSetTotalSubdomains(), PCGASMSetSubdomains(), PCGASMGetSubKSP(), 1010 PCGASMCreateSubdomains2D(), PCGASMGetSubdomains() 1011 @*/ 1012 PetscErrorCode PCGASMSetOverlap(PC pc,PetscInt ovl) 1013 { 1014 PetscErrorCode ierr; 1015 1016 PetscFunctionBegin; 1017 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1018 PetscValidLogicalCollectiveInt(pc,ovl,2); 1019 ierr = PetscTryMethod(pc,"PCGASMSetOverlap_C",(PC,PetscInt),(pc,ovl));CHKERRQ(ierr); 1020 PetscFunctionReturn(0); 1021 } 1022 1023 #undef __FUNCT__ 1024 #define __FUNCT__ "PCGASMSetType" 1025 /*@ 1026 PCGASMSetType - Sets the type of restriction and interpolation used 1027 for local problems in the additive Schwarz method. 1028 1029 Logically Collective on PC 1030 1031 Input Parameters: 1032 + pc - the preconditioner context 1033 - type - variant of GASM, one of 1034 .vb 1035 PC_GASM_BASIC - full interpolation and restriction 1036 PC_GASM_RESTRICT - full restriction, local processor interpolation 1037 PC_GASM_INTERPOLATE - full interpolation, local processor restriction 1038 PC_GASM_NONE - local processor restriction and interpolation 1039 .ve 1040 1041 Options Database Key: 1042 . -pc_gasm_type [basic,restrict,interpolate,none] - Sets GASM type 1043 1044 Level: intermediate 1045 1046 .keywords: PC, GASM, set, type 1047 1048 .seealso: PCGASMSetTotalSubdomains(), PCGASMSetSubdomains(), PCGASMGetSubKSP(), 1049 PCGASMCreateSubdomains2D() 1050 @*/ 1051 PetscErrorCode PCGASMSetType(PC pc,PCGASMType type) 1052 { 1053 PetscErrorCode ierr; 1054 1055 PetscFunctionBegin; 1056 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1057 PetscValidLogicalCollectiveEnum(pc,type,2); 1058 ierr = PetscTryMethod(pc,"PCGASMSetType_C",(PC,PCGASMType),(pc,type));CHKERRQ(ierr); 1059 PetscFunctionReturn(0); 1060 } 1061 1062 #undef __FUNCT__ 1063 #define __FUNCT__ "PCGASMSetSortIndices" 1064 /*@ 1065 PCGASMSetSortIndices - Determines whether subdomain indices are sorted. 1066 1067 Logically Collective on PC 1068 1069 Input Parameters: 1070 + pc - the preconditioner context 1071 - doSort - sort the subdomain indices 1072 1073 Level: intermediate 1074 1075 .keywords: PC, GASM, set, type 1076 1077 .seealso: PCGASMSetSubdomains(), PCGASMSetTotalSubdomains(), PCGASMGetSubKSP(), 1078 PCGASMCreateSubdomains2D() 1079 @*/ 1080 PetscErrorCode PCGASMSetSortIndices(PC pc,PetscBool doSort) 1081 { 1082 PetscErrorCode ierr; 1083 1084 PetscFunctionBegin; 1085 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1086 PetscValidLogicalCollectiveBool(pc,doSort,2); 1087 ierr = PetscTryMethod(pc,"PCGASMSetSortIndices_C",(PC,PetscBool),(pc,doSort));CHKERRQ(ierr); 1088 PetscFunctionReturn(0); 1089 } 1090 1091 #undef __FUNCT__ 1092 #define __FUNCT__ "PCGASMGetSubKSP" 1093 /*@C 1094 PCGASMGetSubKSP - Gets the local KSP contexts for all blocks on 1095 this processor. 1096 1097 Collective on PC iff first_local is requested 1098 1099 Input Parameter: 1100 . pc - the preconditioner context 1101 1102 Output Parameters: 1103 + n_local - the number of blocks on this processor or PETSC_NULL 1104 . first_local - the global number of the first block on this processor or PETSC_NULL, 1105 all processors must request or all must pass PETSC_NULL 1106 - ksp - the array of KSP contexts 1107 1108 Note: 1109 After PCGASMGetSubKSP() the array of KSPes is not to be freed 1110 1111 Currently for some matrix implementations only 1 block per processor 1112 is supported. 1113 1114 You must call KSPSetUp() before calling PCGASMGetSubKSP(). 1115 1116 Level: advanced 1117 1118 .keywords: PC, GASM, additive Schwarz, get, sub, KSP, context 1119 1120 .seealso: PCGASMSetTotalSubdomains(), PCGASMSetSubdomains(), PCGASMSetOverlap(), 1121 PCGASMCreateSubdomains2D(), 1122 @*/ 1123 PetscErrorCode PCGASMGetSubKSP(PC pc,PetscInt *n_local,PetscInt *first_local,KSP *ksp[]) 1124 { 1125 PetscErrorCode ierr; 1126 1127 PetscFunctionBegin; 1128 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1129 ierr = PetscUseMethod(pc,"PCGASMGetSubKSP_C",(PC,PetscInt*,PetscInt*,KSP **),(pc,n_local,first_local,ksp));CHKERRQ(ierr); 1130 PetscFunctionReturn(0); 1131 } 1132 1133 /* -------------------------------------------------------------------------------------*/ 1134 /*MC 1135 PCGASM - Use the (restricted) additive Schwarz method, each block is (approximately) solved with 1136 its own KSP object. 1137 1138 Options Database Keys: 1139 + -pc_gasm_total_block_count <n> - Sets total number of local subdomains (known as blocks) to be distributed among processors 1140 . -pc_gasm_view_subdomains - activates the printing of subdomain indices in PCView(), -ksp_view or -snes_view 1141 . -pc_gasm_print_subdomains - activates the printing of subdomain indices in PCSetUp() 1142 . -pc_gasm_overlap <ovl> - Sets overlap by which to (automatically) extend local subdomains 1143 - -pc_gasm_type [basic,restrict,interpolate,none] - Sets GASM type 1144 1145 IMPORTANT: If you run with, for example, 3 blocks on 1 processor or 3 blocks on 3 processors you 1146 will get a different convergence rate due to the default option of -pc_gasm_type restrict. Use 1147 -pc_gasm_type basic to use the standard GASM. 1148 1149 Notes: Each processor can have one or more blocks, but a block cannot be shared by more 1150 than one processor. Defaults to one block per processor. 1151 1152 To set options on the solvers for each block append -sub_ to all the KSP, and PC 1153 options database keys. For example, -sub_pc_type ilu -sub_pc_factor_levels 1 -sub_ksp_type preonly 1154 1155 To set the options on the solvers separate for each block call PCGASMGetSubKSP() 1156 and set the options directly on the resulting KSP object (you can access its PC 1157 with KSPGetPC()) 1158 1159 1160 Level: beginner 1161 1162 Concepts: additive Schwarz method 1163 1164 References: 1165 An additive variant of the Schwarz alternating method for the case of many subregions 1166 M Dryja, OB Widlund - Courant Institute, New York University Technical report 1167 1168 Domain Decompositions: Parallel Multilevel Methods for Elliptic Partial Differential Equations, 1169 Barry Smith, Petter Bjorstad, and William Gropp, Cambridge University Press, ISBN 0-521-49589-X. 1170 1171 .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC, 1172 PCBJACOBI, PCGASMSetUseTrueLocal(), PCGASMGetSubKSP(), PCGASMSetSubdomains(), 1173 PCGASMSetTotalSubdomains(), PCSetModifySubmatrices(), PCGASMSetOverlap(), PCGASMSetType() 1174 1175 M*/ 1176 1177 EXTERN_C_BEGIN 1178 #undef __FUNCT__ 1179 #define __FUNCT__ "PCCreate_GASM" 1180 PetscErrorCode PCCreate_GASM(PC pc) 1181 { 1182 PetscErrorCode ierr; 1183 PC_GASM *osm; 1184 1185 PetscFunctionBegin; 1186 ierr = PetscNewLog(pc,PC_GASM,&osm);CHKERRQ(ierr); 1187 osm->N = PETSC_DECIDE; 1188 osm->n = PETSC_DECIDE; 1189 osm->nmax = 0; 1190 osm->overlap = 1; 1191 osm->ksp = 0; 1192 osm->gorestriction = 0; 1193 osm->girestriction = 0; 1194 osm->gx = 0; 1195 osm->gy = 0; 1196 osm->x = 0; 1197 osm->y = 0; 1198 osm->ois = 0; 1199 osm->iis = 0; 1200 osm->pmat = 0; 1201 osm->type = PC_GASM_RESTRICT; 1202 osm->same_subdomain_solvers = PETSC_TRUE; 1203 osm->sort_indices = PETSC_TRUE; 1204 1205 pc->data = (void*)osm; 1206 pc->ops->apply = PCApply_GASM; 1207 pc->ops->applytranspose = PCApplyTranspose_GASM; 1208 pc->ops->setup = PCSetUp_GASM; 1209 pc->ops->reset = PCReset_GASM; 1210 pc->ops->destroy = PCDestroy_GASM; 1211 pc->ops->setfromoptions = PCSetFromOptions_GASM; 1212 pc->ops->setuponblocks = PCSetUpOnBlocks_GASM; 1213 pc->ops->view = PCView_GASM; 1214 pc->ops->applyrichardson = 0; 1215 1216 ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCGASMSetSubdomains_C","PCGASMSetSubdomains_GASM", 1217 PCGASMSetSubdomains_GASM);CHKERRQ(ierr); 1218 ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCGASMSetTotalSubdomains_C","PCGASMSetTotalSubdomains_GASM", 1219 PCGASMSetTotalSubdomains_GASM);CHKERRQ(ierr); 1220 ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCGASMSetOverlap_C","PCGASMSetOverlap_GASM", 1221 PCGASMSetOverlap_GASM);CHKERRQ(ierr); 1222 ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCGASMSetType_C","PCGASMSetType_GASM", 1223 PCGASMSetType_GASM);CHKERRQ(ierr); 1224 ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCGASMSetSortIndices_C","PCGASMSetSortIndices_GASM", 1225 PCGASMSetSortIndices_GASM);CHKERRQ(ierr); 1226 ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCGASMGetSubKSP_C","PCGASMGetSubKSP_GASM", 1227 PCGASMGetSubKSP_GASM);CHKERRQ(ierr); 1228 PetscFunctionReturn(0); 1229 } 1230 EXTERN_C_END 1231 1232 1233 #undef __FUNCT__ 1234 #define __FUNCT__ "PCGASMCreateLocalSubdomains" 1235 /*@C 1236 PCGASMCreateLocalSubdomains - Creates n local index sets for the overlapping 1237 Schwarz preconditioner for a any problem based on its matrix. 1238 1239 Collective 1240 1241 Input Parameters: 1242 + A - The global matrix operator 1243 . overlap - amount of overlap in outer subdomains 1244 - n - the number of local subdomains 1245 1246 Output Parameters: 1247 + iis - the array of index sets defining the local inner subdomains (on which the correction is applied) 1248 - ois - the array of index sets defining the local outer subdomains (on which the residual is computed) 1249 1250 Level: advanced 1251 1252 Note: this generates n nonoverlapping local inner subdomains on PETSC_COMM_SELF; 1253 PCGASM will generate the overlap from these if you use them in PCGASMSetSubdomains() and set a 1254 nonzero overlap with PCGASMSetOverlap() 1255 1256 In the Fortran version you must provide the array outis[] already allocated of length n. 1257 1258 .keywords: PC, GASM, additive Schwarz, create, subdomains, unstructured grid 1259 1260 .seealso: PCGASMSetSubdomains(), PCGASMDestroySubdomains() 1261 @*/ 1262 PetscErrorCode PCGASMCreateLocalSubdomains(Mat A, PetscInt overlap, PetscInt n, IS* iis[], IS* ois[]) 1263 { 1264 MatPartitioning mpart; 1265 const char *prefix; 1266 PetscErrorCode (*f)(Mat,MatReuse,Mat*); 1267 PetscMPIInt size; 1268 PetscInt i,j,rstart,rend,bs; 1269 PetscBool isbaij = PETSC_FALSE,foundpart = PETSC_FALSE; 1270 Mat Ad = PETSC_NULL, adj; 1271 IS ispart,isnumb,*is; 1272 PetscErrorCode ierr; 1273 1274 PetscFunctionBegin; 1275 PetscValidHeaderSpecific(A,MAT_CLASSID,1); 1276 PetscValidPointer(iis,4); 1277 if (n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of local blocks must be > 0, n = %D",n); 1278 1279 /* Get prefix, row distribution, and block size */ 1280 ierr = MatGetOptionsPrefix(A,&prefix);CHKERRQ(ierr); 1281 ierr = MatGetOwnershipRange(A,&rstart,&rend);CHKERRQ(ierr); 1282 ierr = MatGetBlockSize(A,&bs);CHKERRQ(ierr); 1283 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); 1284 1285 /* Get diagonal block from matrix if possible */ 1286 ierr = MPI_Comm_size(((PetscObject)A)->comm,&size);CHKERRQ(ierr); 1287 ierr = PetscObjectQueryFunction((PetscObject)A,"MatGetDiagonalBlock_C",(void (**)(void))&f);CHKERRQ(ierr); 1288 if (f) { 1289 ierr = MatGetDiagonalBlock(A,&Ad);CHKERRQ(ierr); 1290 } else if (size == 1) { 1291 Ad = A; 1292 } 1293 if (Ad) { 1294 ierr = PetscObjectTypeCompare((PetscObject)Ad,MATSEQBAIJ,&isbaij);CHKERRQ(ierr); 1295 if (!isbaij) {ierr = PetscObjectTypeCompare((PetscObject)Ad,MATSEQSBAIJ,&isbaij);CHKERRQ(ierr);} 1296 } 1297 if (Ad && n > 1) { 1298 PetscBool match,done; 1299 /* Try to setup a good matrix partitioning if available */ 1300 ierr = MatPartitioningCreate(PETSC_COMM_SELF,&mpart);CHKERRQ(ierr); 1301 ierr = PetscObjectSetOptionsPrefix((PetscObject)mpart,prefix);CHKERRQ(ierr); 1302 ierr = MatPartitioningSetFromOptions(mpart);CHKERRQ(ierr); 1303 ierr = PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGCURRENT,&match);CHKERRQ(ierr); 1304 if (!match) { 1305 ierr = PetscObjectTypeCompare((PetscObject)mpart,MATPARTITIONINGSQUARE,&match);CHKERRQ(ierr); 1306 } 1307 if (!match) { /* assume a "good" partitioner is available */ 1308 PetscInt na; 1309 const PetscInt *ia,*ja; 1310 ierr = MatGetRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);CHKERRQ(ierr); 1311 if (done) { 1312 /* Build adjacency matrix by hand. Unfortunately a call to 1313 MatConvert(Ad,MATMPIADJ,MAT_INITIAL_MATRIX,&adj) will 1314 remove the block-aij structure and we cannot expect 1315 MatPartitioning to split vertices as we need */ 1316 PetscInt i,j,len,nnz,cnt,*iia=0,*jja=0; 1317 const PetscInt *row; 1318 nnz = 0; 1319 for (i=0; i<na; i++) { /* count number of nonzeros */ 1320 len = ia[i+1] - ia[i]; 1321 row = ja + ia[i]; 1322 for (j=0; j<len; j++) { 1323 if (row[j] == i) { /* don't count diagonal */ 1324 len--; break; 1325 } 1326 } 1327 nnz += len; 1328 } 1329 ierr = PetscMalloc((na+1)*sizeof(PetscInt),&iia);CHKERRQ(ierr); 1330 ierr = PetscMalloc((nnz)*sizeof(PetscInt),&jja);CHKERRQ(ierr); 1331 nnz = 0; 1332 iia[0] = 0; 1333 for (i=0; i<na; i++) { /* fill adjacency */ 1334 cnt = 0; 1335 len = ia[i+1] - ia[i]; 1336 row = ja + ia[i]; 1337 for (j=0; j<len; j++) { 1338 if (row[j] != i) { /* if not diagonal */ 1339 jja[nnz+cnt++] = row[j]; 1340 } 1341 } 1342 nnz += cnt; 1343 iia[i+1] = nnz; 1344 } 1345 /* Partitioning of the adjacency matrix */ 1346 ierr = MatCreateMPIAdj(PETSC_COMM_SELF,na,na,iia,jja,PETSC_NULL,&adj);CHKERRQ(ierr); 1347 ierr = MatPartitioningSetAdjacency(mpart,adj);CHKERRQ(ierr); 1348 ierr = MatPartitioningSetNParts(mpart,n);CHKERRQ(ierr); 1349 ierr = MatPartitioningApply(mpart,&ispart);CHKERRQ(ierr); 1350 ierr = ISPartitioningToNumbering(ispart,&isnumb);CHKERRQ(ierr); 1351 ierr = MatDestroy(&adj);CHKERRQ(ierr); 1352 foundpart = PETSC_TRUE; 1353 } 1354 ierr = MatRestoreRowIJ(Ad,0,PETSC_TRUE,isbaij,&na,&ia,&ja,&done);CHKERRQ(ierr); 1355 } 1356 ierr = MatPartitioningDestroy(&mpart);CHKERRQ(ierr); 1357 } 1358 ierr = PetscMalloc(n*sizeof(IS),&is);CHKERRQ(ierr); 1359 if (!foundpart) { 1360 1361 /* Partitioning by contiguous chunks of rows */ 1362 1363 PetscInt mbs = (rend-rstart)/bs; 1364 PetscInt start = rstart; 1365 for (i=0; i<n; i++) { 1366 PetscInt count = (mbs/n + ((mbs % n) > i)) * bs; 1367 ierr = ISCreateStride(PETSC_COMM_SELF,count,start,1,&is[i]);CHKERRQ(ierr); 1368 start += count; 1369 } 1370 1371 } else { 1372 1373 /* Partitioning by adjacency of diagonal block */ 1374 1375 const PetscInt *numbering; 1376 PetscInt *count,nidx,*indices,*newidx,start=0; 1377 /* Get node count in each partition */ 1378 ierr = PetscMalloc(n*sizeof(PetscInt),&count);CHKERRQ(ierr); 1379 ierr = ISPartitioningCount(ispart,n,count);CHKERRQ(ierr); 1380 if (isbaij && bs > 1) { /* adjust for the block-aij case */ 1381 for (i=0; i<n; i++) count[i] *= bs; 1382 } 1383 /* Build indices from node numbering */ 1384 ierr = ISGetLocalSize(isnumb,&nidx);CHKERRQ(ierr); 1385 ierr = PetscMalloc(nidx*sizeof(PetscInt),&indices);CHKERRQ(ierr); 1386 for (i=0; i<nidx; i++) indices[i] = i; /* needs to be initialized */ 1387 ierr = ISGetIndices(isnumb,&numbering);CHKERRQ(ierr); 1388 ierr = PetscSortIntWithPermutation(nidx,numbering,indices);CHKERRQ(ierr); 1389 ierr = ISRestoreIndices(isnumb,&numbering);CHKERRQ(ierr); 1390 if (isbaij && bs > 1) { /* adjust for the block-aij case */ 1391 ierr = PetscMalloc(nidx*bs*sizeof(PetscInt),&newidx);CHKERRQ(ierr); 1392 for (i=0; i<nidx; i++) 1393 for (j=0; j<bs; j++) 1394 newidx[i*bs+j] = indices[i]*bs + j; 1395 ierr = PetscFree(indices);CHKERRQ(ierr); 1396 nidx *= bs; 1397 indices = newidx; 1398 } 1399 /* Shift to get global indices */ 1400 for (i=0; i<nidx; i++) indices[i] += rstart; 1401 1402 /* Build the index sets for each block */ 1403 for (i=0; i<n; i++) { 1404 ierr = ISCreateGeneral(PETSC_COMM_SELF,count[i],&indices[start],PETSC_COPY_VALUES,&is[i]);CHKERRQ(ierr); 1405 ierr = ISSort(is[i]);CHKERRQ(ierr); 1406 start += count[i]; 1407 } 1408 1409 ierr = PetscFree(count); 1410 ierr = PetscFree(indices); 1411 ierr = ISDestroy(&isnumb);CHKERRQ(ierr); 1412 ierr = ISDestroy(&ispart);CHKERRQ(ierr); 1413 } 1414 *iis = is; 1415 if (!ois) PetscFunctionReturn(0); 1416 /* 1417 Initially make outer subdomains the same as inner subdomains. If nonzero additional overlap 1418 has been requested, copy the inner subdomains over so they can be modified. 1419 */ 1420 ierr = PetscMalloc(n*sizeof(IS),ois);CHKERRQ(ierr); 1421 for (i=0; i<n; ++i) { 1422 if (overlap > 0) { /* With positive overlap, (*iis)[i] will be modified */ 1423 ierr = ISDuplicate((*iis)[i],(*ois)+i);CHKERRQ(ierr); 1424 ierr = ISCopy((*iis)[i],(*ois)[i]);CHKERRQ(ierr); 1425 } else { 1426 ierr = PetscObjectReference((PetscObject)(*iis)[i]);CHKERRQ(ierr); 1427 (*ois)[i] = (*iis)[i]; 1428 } 1429 } 1430 if (overlap > 0) { 1431 /* Extend the "overlapping" regions by a number of steps */ 1432 ierr = MatIncreaseOverlap(A,n,*ois,overlap);CHKERRQ(ierr); 1433 } 1434 PetscFunctionReturn(0); 1435 } 1436 1437 #undef __FUNCT__ 1438 #define __FUNCT__ "PCGASMDestroySubdomains" 1439 /*@C 1440 PCGASMDestroySubdomains - Destroys the index sets created with 1441 PCGASMCreateLocalSubdomains() or PCGASMCreateSubdomains2D. Should be 1442 called after setting subdomains with PCGASMSetSubdomains(). 1443 1444 Collective 1445 1446 Input Parameters: 1447 + n - the number of index sets 1448 . iis - the array of inner subdomains, 1449 - ois - the array of outer subdomains, can be PETSC_NULL 1450 1451 Level: intermediate 1452 1453 Notes: this is merely a convenience subroutine that walks each list, 1454 destroys each IS on the list, and then frees the list. 1455 1456 .keywords: PC, GASM, additive Schwarz, create, subdomains, unstructured grid 1457 1458 .seealso: PCGASMCreateLocalSubdomains(), PCGASMSetSubdomains() 1459 @*/ 1460 PetscErrorCode PCGASMDestroySubdomains(PetscInt n, IS iis[], IS ois[]) 1461 { 1462 PetscInt i; 1463 PetscErrorCode ierr; 1464 PetscFunctionBegin; 1465 if (n <= 0) PetscFunctionReturn(0); 1466 if (iis) { 1467 PetscValidPointer(iis,2); 1468 for (i=0; i<n; i++) { 1469 ierr = ISDestroy(&iis[i]);CHKERRQ(ierr); 1470 } 1471 ierr = PetscFree(iis);CHKERRQ(ierr); 1472 } 1473 if (ois) { 1474 for (i=0; i<n; i++) { 1475 ierr = ISDestroy(&ois[i]);CHKERRQ(ierr); 1476 } 1477 ierr = PetscFree(ois);CHKERRQ(ierr); 1478 } 1479 PetscFunctionReturn(0); 1480 } 1481 1482 1483 #define PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,xleft_loc,ylow_loc,xright_loc,yhigh_loc,n) \ 1484 { \ 1485 PetscInt first_row = first/M, last_row = last/M+1; \ 1486 /* \ 1487 Compute ylow_loc and yhigh_loc so that (ylow_loc,xleft) and (yhigh_loc,xright) are the corners \ 1488 of the bounding box of the intersection of the subdomain with the local ownership range (local \ 1489 subdomain). \ 1490 Also compute xleft_loc and xright_loc as the lower and upper bounds on the first and last rows \ 1491 of the intersection. \ 1492 */ \ 1493 /* ylow_loc is the grid row containing the first element of the local sumbdomain */ \ 1494 *ylow_loc = PetscMax(first_row,ylow); \ 1495 /* xleft_loc is the offset of first element of the local subdomain within its grid row (might actually be outside the local subdomain) */ \ 1496 *xleft_loc = *ylow_loc==first_row?PetscMax(first%M,xleft):xleft; \ 1497 /* yhigh_loc is the grid row above the last local subdomain element */ \ 1498 *yhigh_loc = PetscMin(last_row,yhigh); \ 1499 /* xright is the offset of the end of the local subdomain within its grid row (might actually be outside the local subdomain) */ \ 1500 *xright_loc = *yhigh_loc==last_row?PetscMin(xright,last%M):xright; \ 1501 /* Now compute the size of the local subdomain n. */ \ 1502 *n = 0; \ 1503 if (*ylow_loc < *yhigh_loc) { \ 1504 PetscInt width = xright-xleft; \ 1505 *n += width*(*yhigh_loc-*ylow_loc-1); \ 1506 *n += PetscMin(PetscMax(*xright_loc-xleft,0),width); \ 1507 *n -= PetscMin(PetscMax(*xleft_loc-xleft,0), width); \ 1508 }\ 1509 } 1510 1511 1512 1513 #undef __FUNCT__ 1514 #define __FUNCT__ "PCGASMCreateSubdomains2D" 1515 /*@ 1516 PCGASMCreateSubdomains2D - Creates the index sets for the overlapping Schwarz 1517 preconditioner for a two-dimensional problem on a regular grid. 1518 1519 Collective 1520 1521 Input Parameters: 1522 + M, N - the global number of grid points in the x and y directions 1523 . Mdomains, Ndomains - the global number of subdomains in the x and y directions 1524 . dof - degrees of freedom per node 1525 - overlap - overlap in mesh lines 1526 1527 Output Parameters: 1528 + Nsub - the number of local subdomains created 1529 . iis - array of index sets defining inner (nonoverlapping) subdomains 1530 - ois - array of index sets defining outer (overlapping, if overlap > 0) subdomains 1531 1532 1533 Level: advanced 1534 1535 .keywords: PC, GASM, additive Schwarz, create, subdomains, 2D, regular grid 1536 1537 .seealso: PCGASMSetTotalSubdomains(), PCGASMSetSubdomains(), PCGASMGetSubKSP(), 1538 PCGASMSetOverlap() 1539 @*/ 1540 PetscErrorCode PCGASMCreateSubdomains2D(PC pc, PetscInt M,PetscInt N,PetscInt Mdomains,PetscInt Ndomains,PetscInt dof,PetscInt overlap, PetscInt *nsub,IS **iis,IS **ois) 1541 { 1542 PetscErrorCode ierr; 1543 PetscMPIInt size, rank; 1544 PetscInt i, j; 1545 PetscInt maxheight, maxwidth; 1546 PetscInt xstart, xleft, xright, xleft_loc, xright_loc; 1547 PetscInt ystart, ylow, yhigh, ylow_loc, yhigh_loc; 1548 PetscInt x[2][2], y[2][2], n[2]; 1549 PetscInt first, last; 1550 PetscInt nidx, *idx; 1551 PetscInt ii,jj,s,q,d; 1552 PetscInt k,kk; 1553 PetscMPIInt color; 1554 MPI_Comm comm, subcomm; 1555 IS **xis = 0, **is = ois, **is_local = iis; 1556 1557 PetscFunctionBegin; 1558 ierr = PetscObjectGetComm((PetscObject)pc, &comm);CHKERRQ(ierr); 1559 ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr); 1560 ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr); 1561 ierr = MatGetOwnershipRange(pc->pmat, &first, &last);CHKERRQ(ierr); 1562 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) " 1563 "does not respect the number of degrees of freedom per grid point %D", first, last, dof); 1564 1565 /* Determine the number of domains with nonzero intersections with the local ownership range. */ 1566 s = 0; 1567 ystart = 0; 1568 for (j=0; j<Ndomains; ++j) { 1569 maxheight = N/Ndomains + ((N % Ndomains) > j); /* Maximal height of subdomain */ 1570 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); 1571 /* Vertical domain limits with an overlap. */ 1572 ylow = PetscMax(ystart - overlap,0); 1573 yhigh = PetscMin(ystart + maxheight + overlap,N); 1574 xstart = 0; 1575 for (i=0; i<Mdomains; ++i) { 1576 maxwidth = M/Mdomains + ((M % Mdomains) > i); /* Maximal width of subdomain */ 1577 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); 1578 /* Horizontal domain limits with an overlap. */ 1579 xleft = PetscMax(xstart - overlap,0); 1580 xright = PetscMin(xstart + maxwidth + overlap,M); 1581 /* 1582 Determine whether this subdomain intersects this processor's ownership range of pc->pmat. 1583 */ 1584 PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,(&xleft_loc),(&ylow_loc),(&xright_loc),(&yhigh_loc),(&nidx)); 1585 if (nidx) { 1586 ++s; 1587 } 1588 xstart += maxwidth; 1589 }/* for (i = 0; i < Mdomains; ++i) */ 1590 ystart += maxheight; 1591 }/* for (j = 0; j < Ndomains; ++j) */ 1592 /* Now we can allocate the necessary number of ISs. */ 1593 *nsub = s; 1594 ierr = PetscMalloc((*nsub)*sizeof(IS*),is);CHKERRQ(ierr); 1595 ierr = PetscMalloc((*nsub)*sizeof(IS*),is_local);CHKERRQ(ierr); 1596 s = 0; 1597 ystart = 0; 1598 for (j=0; j<Ndomains; ++j) { 1599 maxheight = N/Ndomains + ((N % Ndomains) > j); /* Maximal height of subdomain */ 1600 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); 1601 /* Vertical domain limits with an overlap. */ 1602 y[0][0] = PetscMax(ystart - overlap,0); 1603 y[0][1] = PetscMin(ystart + maxheight + overlap,N); 1604 /* Vertical domain limits without an overlap. */ 1605 y[1][0] = ystart; 1606 y[1][1] = PetscMin(ystart + maxheight,N); 1607 xstart = 0; 1608 for (i=0; i<Mdomains; ++i) { 1609 maxwidth = M/Mdomains + ((M % Mdomains) > i); /* Maximal width of subdomain */ 1610 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); 1611 /* Horizontal domain limits with an overlap. */ 1612 x[0][0] = PetscMax(xstart - overlap,0); 1613 x[0][1] = PetscMin(xstart + maxwidth + overlap,M); 1614 /* Horizontal domain limits without an overlap. */ 1615 x[1][0] = xstart; 1616 x[1][1] = PetscMin(xstart+maxwidth,M); 1617 /* 1618 Determine whether this domain intersects this processor's ownership range of pc->pmat. 1619 Do this twice: first for the domains with overlaps, and once without. 1620 During the first pass create the subcommunicators, and use them on the second pass as well. 1621 */ 1622 for (q = 0; q < 2; ++q) { 1623 /* 1624 domain limits, (xleft, xright) and (ylow, yheigh) are adjusted 1625 according to whether the domain with an overlap or without is considered. 1626 */ 1627 xleft = x[q][0]; xright = x[q][1]; 1628 ylow = y[q][0]; yhigh = y[q][1]; 1629 PCGASMLocalSubdomainBounds2D(M,N,xleft,ylow,xright,yhigh,first,last,(&xleft_loc),(&ylow_loc),(&xright_loc),(&yhigh_loc),(&nidx)); 1630 nidx *= dof; 1631 n[q] = nidx; 1632 /* 1633 Based on the counted number of indices in the local domain *with an overlap*, 1634 construct a subcommunicator of all the processors supporting this domain. 1635 Observe that a domain with an overlap might have nontrivial local support, 1636 while the domain without an overlap might not. Hence, the decision to participate 1637 in the subcommunicator must be based on the domain with an overlap. 1638 */ 1639 if (q == 0) { 1640 if (nidx) { 1641 color = 1; 1642 } else { 1643 color = MPI_UNDEFINED; 1644 } 1645 ierr = MPI_Comm_split(comm, color, rank, &subcomm);CHKERRQ(ierr); 1646 } 1647 /* 1648 Proceed only if the number of local indices *with an overlap* is nonzero. 1649 */ 1650 if (n[0]) { 1651 if (q == 0) { 1652 xis = is; 1653 } 1654 if (q == 1) { 1655 /* 1656 The IS for the no-overlap subdomain shares a communicator with the overlapping domain. 1657 Moreover, if the overlap is zero, the two ISs are identical. 1658 */ 1659 if (overlap == 0) { 1660 (*is_local)[s] = (*is)[s]; 1661 ierr = PetscObjectReference((PetscObject)(*is)[s]);CHKERRQ(ierr); 1662 continue; 1663 } else { 1664 xis = is_local; 1665 subcomm = ((PetscObject)(*is)[s])->comm; 1666 } 1667 }/* if (q == 1) */ 1668 idx = PETSC_NULL; 1669 ierr = PetscMalloc(nidx*sizeof(PetscInt),&idx);CHKERRQ(ierr); 1670 if (nidx) { 1671 k = 0; 1672 for (jj=ylow_loc; jj<yhigh_loc; ++jj) { 1673 PetscInt x0 = (jj==ylow_loc)?xleft_loc:xleft; 1674 PetscInt x1 = (jj==yhigh_loc-1)?xright_loc:xright; 1675 kk = dof*(M*jj + x0); 1676 for (ii=x0; ii<x1; ++ii) { 1677 for (d = 0; d < dof; ++d) { 1678 idx[k++] = kk++; 1679 } 1680 } 1681 } 1682 } 1683 ierr = ISCreateGeneral(subcomm,nidx,idx,PETSC_OWN_POINTER,(*xis)+s);CHKERRQ(ierr); 1684 }/* if (n[0]) */ 1685 }/* for (q = 0; q < 2; ++q) */ 1686 if (n[0]) { 1687 ++s; 1688 } 1689 xstart += maxwidth; 1690 }/* for (i = 0; i < Mdomains; ++i) */ 1691 ystart += maxheight; 1692 }/* for (j = 0; j < Ndomains; ++j) */ 1693 PetscFunctionReturn(0); 1694 } 1695 1696 #undef __FUNCT__ 1697 #define __FUNCT__ "PCGASMGetSubdomains" 1698 /*@C 1699 PCGASMGetSubdomains - Gets the subdomains supported on this processor 1700 for the additive Schwarz preconditioner. 1701 1702 Not Collective 1703 1704 Input Parameter: 1705 . pc - the preconditioner context 1706 1707 Output Parameters: 1708 + n - the number of subdomains for this processor (default value = 1) 1709 . iis - the index sets that define the inner subdomains (without overlap) supported on this processor (can be PETSC_NULL) 1710 - ois - the index sets that define the outer subdomains (with overlap) supported on this processor (can be PETSC_NULL) 1711 1712 1713 Notes: 1714 The user is responsible for destroying the ISs and freeing the returned arrays. 1715 The IS numbering is in the parallel, global numbering of the vector. 1716 1717 Level: advanced 1718 1719 .keywords: PC, GASM, get, subdomains, additive Schwarz 1720 1721 .seealso: PCGASMSetTotalSubdomains(), PCGASMSetOverlap(), PCGASMGetSubKSP(), 1722 PCGASMCreateSubdomains2D(), PCGASMSetSubdomains(), PCGASMGetSubmatrices() 1723 @*/ 1724 PetscErrorCode PCGASMGetSubdomains(PC pc,PetscInt *n,IS *iis[],IS *ois[]) 1725 { 1726 PC_GASM *osm; 1727 PetscErrorCode ierr; 1728 PetscBool match; 1729 PetscInt i; 1730 PetscFunctionBegin; 1731 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1732 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1733 if (!match) 1734 SETERRQ2(((PetscObject)pc)->comm, PETSC_ERR_ARG_WRONG, "Incorrect object type: expected %s, got %s instead", PCGASM, ((PetscObject)pc)->type_name); 1735 osm = (PC_GASM*)pc->data; 1736 if (n) *n = osm->n; 1737 if (iis) { 1738 ierr = PetscMalloc(osm->n*sizeof(IS), iis);CHKERRQ(ierr); 1739 } 1740 if (ois) { 1741 ierr = PetscMalloc(osm->n*sizeof(IS), ois);CHKERRQ(ierr); 1742 } 1743 if (iis || ois) { 1744 for (i = 0; i < osm->n; ++i) { 1745 if (iis) (*iis)[i] = osm->iis[i]; 1746 if (ois) (*ois)[i] = osm->ois[i]; 1747 } 1748 } 1749 PetscFunctionReturn(0); 1750 } 1751 1752 #undef __FUNCT__ 1753 #define __FUNCT__ "PCGASMGetSubmatrices" 1754 /*@C 1755 PCGASMGetSubmatrices - Gets the local submatrices (for this processor 1756 only) for the additive Schwarz preconditioner. 1757 1758 Not Collective 1759 1760 Input Parameter: 1761 . pc - the preconditioner context 1762 1763 Output Parameters: 1764 + n - the number of matrices for this processor (default value = 1) 1765 - mat - the matrices 1766 1767 Notes: matrices returned by this routine have the same communicators as the index sets (IS) 1768 used to define subdomains in PCGASMSetSubdomains(), or PETSC_COMM_SELF, if the 1769 subdomains were defined using PCGASMSetTotalSubdomains(). 1770 Level: advanced 1771 1772 .keywords: PC, GASM, set, local, subdomains, additive Schwarz, block Jacobi 1773 1774 .seealso: PCGASMSetTotalSubdomain(), PCGASMSetOverlap(), PCGASMGetSubKSP(), 1775 PCGASMCreateSubdomains2D(), PCGASMSetSubdomains(), PCGASMGetSubdomains() 1776 @*/ 1777 PetscErrorCode PCGASMGetSubmatrices(PC pc,PetscInt *n,Mat *mat[]) 1778 { 1779 PC_GASM *osm; 1780 PetscErrorCode ierr; 1781 PetscBool match; 1782 1783 PetscFunctionBegin; 1784 PetscValidHeaderSpecific(pc,PC_CLASSID,1); 1785 PetscValidIntPointer(n,2); 1786 if (mat) PetscValidPointer(mat,3); 1787 if (!pc->setupcalled) SETERRQ(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONGSTATE,"Must call after KSPSetUP() or PCSetUp()."); 1788 ierr = PetscObjectTypeCompare((PetscObject)pc,PCGASM,&match);CHKERRQ(ierr); 1789 if (!match) SETERRQ2(((PetscObject)pc)->comm, PETSC_ERR_ARG_WRONG, "Expected %s, got %s instead", PCGASM, ((PetscObject)pc)->type_name); 1790 osm = (PC_GASM*)pc->data; 1791 if (n) *n = osm->n; 1792 if (mat) *mat = osm->pmat; 1793 1794 PetscFunctionReturn(0); 1795 } 1796