1 2 /* 3 Provides utility routines for split MPI communicator. 4 */ 5 #include <petscsys.h> /*I "petscsys.h" I*/ 6 #include <petscviewer.h> 7 8 const char *const PetscSubcommTypes[] = {"GENERAL","CONTIGUOUS","INTERLACED","PetscSubcommType","PETSC_SUBCOMM_",0}; 9 10 extern PetscErrorCode PetscSubcommCreate_contiguous(PetscSubcomm); 11 extern PetscErrorCode PetscSubcommCreate_interlaced(PetscSubcomm); 12 13 #undef __FUNCT__ 14 #define __FUNCT__ "PetscSubcommSetFromOptions" 15 /*@C 16 PetscSubcommSetFromOptions - Allows setting options from a PetscSubcomm 17 18 Collective on PetscSubcomm 19 20 Input Parameter: 21 . psubcomm - PetscSubcomm context 22 23 Level: beginner 24 25 @*/ 26 PetscErrorCode PetscSubcommSetFromOptions(PetscSubcomm psubcomm) 27 { 28 PetscErrorCode ierr; 29 PetscSubcommType type; 30 PetscBool flg; 31 32 PetscFunctionBegin; 33 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"Must call PetscSubcommCreate firt"); 34 35 ierr = PetscOptionsBegin(psubcomm->parent,psubcomm->subcommprefix,"Options for PetscSubcomm",NULL);CHKERRQ(ierr); 36 ierr = PetscOptionsEnum("-psubcomm_type",NULL,NULL,PetscSubcommTypes,(PetscEnum)psubcomm->type,(PetscEnum*)&type,&flg);CHKERRQ(ierr); 37 if (flg && psubcomm->type != type) { 38 /* free old structures */ 39 ierr = PetscCommDestroy(&(psubcomm)->dupparent);CHKERRQ(ierr); 40 ierr = PetscCommDestroy(&(psubcomm)->child);CHKERRQ(ierr); 41 ierr = PetscFree((psubcomm)->subsize);CHKERRQ(ierr); 42 switch (type) { 43 case PETSC_SUBCOMM_GENERAL: 44 SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Runtime option PETSC_SUBCOMM_GENERAL is not supported, use PetscSubcommSetTypeGeneral()"); 45 case PETSC_SUBCOMM_CONTIGUOUS: 46 ierr = PetscSubcommCreate_contiguous(psubcomm);CHKERRQ(ierr); 47 break; 48 case PETSC_SUBCOMM_INTERLACED: 49 ierr = PetscSubcommCreate_interlaced(psubcomm);CHKERRQ(ierr); 50 break; 51 default: 52 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"PetscSubcommType %s is not supported yet",PetscSubcommTypes[type]); 53 } 54 } 55 56 ierr = PetscOptionsName("-psubcomm_view","Triggers display of PetscSubcomm context","PetscSubcommView",&flg);CHKERRQ(ierr); 57 if (flg) { 58 ierr = PetscSubcommView(psubcomm,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 59 } 60 ierr = PetscOptionsEnd();CHKERRQ(ierr); 61 PetscFunctionReturn(0); 62 } 63 64 #undef __FUNCT__ 65 #define __FUNCT__ "PetscSubcommSetOptionsPrefix" 66 /*@C 67 PetscSubcommSetOptionsPrefix - Sets the prefix used for searching for all 68 PetscSubcomm items in the options database. 69 70 Logically collective on PetscSubcomm. 71 72 Level: Intermediate 73 74 Input Parameters: 75 + psubcomm - PetscSubcomm context 76 - prefix - the prefix to prepend all PetscSubcomm item names with. 77 78 @*/ 79 PetscErrorCode PetscSubcommSetOptionsPrefix(PetscSubcomm psubcomm,const char pre[]) 80 { 81 PetscErrorCode ierr; 82 83 PetscFunctionBegin; 84 if (!pre) { 85 ierr = PetscFree(psubcomm->subcommprefix);CHKERRQ(ierr); 86 } else { 87 if (pre[0] == '-') SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Options prefix should not begin with a hypen"); 88 ierr = PetscFree(psubcomm->subcommprefix);CHKERRQ(ierr); 89 ierr = PetscStrallocpy(pre,&(psubcomm->subcommprefix));CHKERRQ(ierr); 90 } 91 PetscFunctionReturn(0); 92 } 93 94 #undef __FUNCT__ 95 #define __FUNCT__ "PetscSubcommView" 96 /*@C 97 PetsSubcommcView - Views a PetscSubcomm of values as either ASCII text or a binary file 98 99 Collective on PetscSubcomm 100 101 Input Parameter: 102 + psubcomm - PetscSubcomm context 103 - viewer - location to view the values 104 105 Level: beginner 106 @*/ 107 PetscErrorCode PetscSubcommView(PetscSubcomm psubcomm,PetscViewer viewer) 108 { 109 PetscErrorCode ierr; 110 PetscBool iascii; 111 PetscViewerFormat format; 112 113 PetscFunctionBegin; 114 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 115 if (iascii) { 116 ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr); 117 if (format == PETSC_VIEWER_DEFAULT) { 118 MPI_Comm comm=psubcomm->parent; 119 PetscMPIInt rank,size,subsize,subrank,duprank; 120 121 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 122 ierr = PetscViewerASCIIPrintf(viewer,"PetscSubcomm type %s with total %d MPI processes:\n",PetscSubcommTypes[psubcomm->type],size);CHKERRQ(ierr); 123 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 124 ierr = MPI_Comm_size(psubcomm->child,&subsize);CHKERRQ(ierr); 125 ierr = MPI_Comm_rank(psubcomm->child,&subrank);CHKERRQ(ierr); 126 ierr = MPI_Comm_rank(psubcomm->dupparent,&duprank);CHKERRQ(ierr); 127 ierr = PetscSynchronizedPrintf(comm," [%d], color %d, sub-size %d, sub-rank %d, duprank %d\n",rank,psubcomm->color,subsize,subrank,duprank);CHKERRQ(ierr); 128 ierr = PetscSynchronizedFlush(comm,PETSC_STDOUT);CHKERRQ(ierr); 129 } 130 } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not supported yet"); 131 PetscFunctionReturn(0); 132 } 133 134 #undef __FUNCT__ 135 #define __FUNCT__ "PetscSubcommSetNumber" 136 /*@C 137 PetscSubcommSetNumber - Set total number of subcommunicators. 138 139 Collective on MPI_Comm 140 141 Input Parameter: 142 + psubcomm - PetscSubcomm context 143 - nsubcomm - the total number of subcommunicators in psubcomm 144 145 Level: advanced 146 147 .keywords: communicator 148 149 .seealso: PetscSubcommCreate(),PetscSubcommDestroy(),PetscSubcommSetType(),PetscSubcommSetTypeGeneral() 150 @*/ 151 PetscErrorCode PetscSubcommSetNumber(PetscSubcomm psubcomm,PetscInt nsubcomm) 152 { 153 PetscErrorCode ierr; 154 MPI_Comm comm=psubcomm->parent; 155 PetscMPIInt msub,size; 156 157 PetscFunctionBegin; 158 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"PetscSubcomm is not created. Call PetscSubcommCreate() first"); 159 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 160 ierr = PetscMPIIntCast(nsubcomm,&msub);CHKERRQ(ierr); 161 if (msub < 1 || msub > size) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Num of subcommunicators %d cannot be < 1 or > input comm size %d",msub,size); 162 163 psubcomm->n = msub; 164 PetscFunctionReturn(0); 165 } 166 167 #undef __FUNCT__ 168 #define __FUNCT__ "PetscSubcommSetType" 169 /*@C 170 PetscSubcommSetType - Set type of subcommunicators. 171 172 Collective on MPI_Comm 173 174 Input Parameter: 175 + psubcomm - PetscSubcomm context 176 - subcommtype - subcommunicator type, PETSC_SUBCOMM_CONTIGUOUS,PETSC_SUBCOMM_INTERLACED 177 178 Level: advanced 179 180 .keywords: communicator 181 182 .seealso: PetscSubcommCreate(),PetscSubcommDestroy(),PetscSubcommSetNumber(),PetscSubcommSetTypeGeneral() 183 @*/ 184 PetscErrorCode PetscSubcommSetType(PetscSubcomm psubcomm,PetscSubcommType subcommtype) 185 { 186 PetscErrorCode ierr; 187 188 PetscFunctionBegin; 189 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"PetscSubcomm is not created. Call PetscSubcommCreate()"); 190 if (psubcomm->n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of subcommunicators %d is incorrect. Call PetscSubcommSetNumber()",psubcomm->n); 191 192 if (subcommtype == PETSC_SUBCOMM_CONTIGUOUS) { 193 ierr = PetscSubcommCreate_contiguous(psubcomm);CHKERRQ(ierr); 194 } else if (subcommtype == PETSC_SUBCOMM_INTERLACED) { 195 ierr = PetscSubcommCreate_interlaced(psubcomm);CHKERRQ(ierr); 196 } else SETERRQ1(psubcomm->parent,PETSC_ERR_SUP,"PetscSubcommType %s is not supported yet",PetscSubcommTypes[subcommtype]); 197 PetscFunctionReturn(0); 198 } 199 200 #undef __FUNCT__ 201 #define __FUNCT__ "PetscSubcommSetTypeGeneral" 202 /*@C 203 PetscSubcommSetTypeGeneral - Set a PetscSubcomm from user's specifications 204 205 Collective on MPI_Comm 206 207 Input Parameter: 208 + psubcomm - PetscSubcomm context 209 . color - control of subset assignment (nonnegative integer). Processes with the same color are in the same subcommunicator. 210 - subrank - rank in the subcommunicator 211 212 Level: advanced 213 214 .keywords: communicator, create 215 216 .seealso: PetscSubcommCreate(),PetscSubcommDestroy(),PetscSubcommSetNumber(),PetscSubcommSetType() 217 @*/ 218 PetscErrorCode PetscSubcommSetTypeGeneral(PetscSubcomm psubcomm,PetscMPIInt color,PetscMPIInt subrank) 219 { 220 PetscErrorCode ierr; 221 MPI_Comm subcomm=0,dupcomm=0,comm=psubcomm->parent; 222 PetscMPIInt size,icolor,duprank,*recvbuf,sendbuf[3],mysubsize,rank,*subsize; 223 PetscMPIInt i,nsubcomm=psubcomm->n; 224 225 PetscFunctionBegin; 226 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"PetscSubcomm is not created. Call PetscSubcommCreate()"); 227 if (nsubcomm < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of subcommunicators %d is incorrect. Call PetscSubcommSetNumber()",nsubcomm); 228 229 ierr = MPI_Comm_split(comm,color,subrank,&subcomm);CHKERRQ(ierr); 230 231 /* create dupcomm with same size as comm, but its rank, duprank, maps subcomm's contiguously into dupcomm */ 232 /* TODO: this can be done in an ostensibly scalale way (i.e., without allocating an array of size 'size') as is done in PetscObjectsCreateGlobalOrdering(). */ 233 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 234 ierr = PetscMalloc1(2*size,&recvbuf);CHKERRQ(ierr); 235 236 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 237 ierr = MPI_Comm_size(subcomm,&mysubsize);CHKERRQ(ierr); 238 239 sendbuf[0] = color; 240 sendbuf[1] = mysubsize; 241 ierr = MPI_Allgather(sendbuf,2,MPI_INT,recvbuf,2,MPI_INT,comm);CHKERRQ(ierr); 242 243 ierr = PetscCalloc1(nsubcomm,&subsize);CHKERRQ(ierr); 244 for (i=0; i<2*size; i+=2) { 245 subsize[recvbuf[i]] = recvbuf[i+1]; 246 } 247 ierr = PetscFree(recvbuf);CHKERRQ(ierr); 248 249 duprank = 0; 250 for (icolor=0; icolor<nsubcomm; icolor++) { 251 if (icolor != color) { /* not color of this process */ 252 duprank += subsize[icolor]; 253 } else { 254 duprank += subrank; 255 break; 256 } 257 } 258 ierr = MPI_Comm_split(comm,0,duprank,&dupcomm);CHKERRQ(ierr); 259 260 ierr = PetscCommDuplicate(dupcomm,&psubcomm->dupparent,NULL);CHKERRQ(ierr); 261 ierr = PetscCommDuplicate(subcomm,&psubcomm->child,NULL);CHKERRQ(ierr); 262 ierr = MPI_Comm_free(&dupcomm);CHKERRQ(ierr); 263 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 264 265 psubcomm->color = color; 266 psubcomm->subsize = subsize; 267 psubcomm->type = PETSC_SUBCOMM_GENERAL; 268 PetscFunctionReturn(0); 269 } 270 271 #undef __FUNCT__ 272 #define __FUNCT__ "PetscSubcommDestroy" 273 PetscErrorCode PetscSubcommDestroy(PetscSubcomm *psubcomm) 274 { 275 PetscErrorCode ierr; 276 277 PetscFunctionBegin; 278 if (!*psubcomm) PetscFunctionReturn(0); 279 ierr = PetscCommDestroy(&(*psubcomm)->dupparent);CHKERRQ(ierr); 280 ierr = PetscCommDestroy(&(*psubcomm)->child);CHKERRQ(ierr); 281 ierr = PetscFree((*psubcomm)->subsize);CHKERRQ(ierr); 282 if ((*psubcomm)->subcommprefix) { ierr = PetscFree((*psubcomm)->subcommprefix);CHKERRQ(ierr); } 283 ierr = PetscFree((*psubcomm));CHKERRQ(ierr); 284 PetscFunctionReturn(0); 285 } 286 287 #undef __FUNCT__ 288 #define __FUNCT__ "PetscSubcommCreate" 289 /*@C 290 PetscSubcommCreate - Create a PetscSubcomm context. 291 292 Collective on MPI_Comm 293 294 Input Parameter: 295 . comm - MPI communicator 296 297 Output Parameter: 298 . psubcomm - location to store the PetscSubcomm context 299 300 Level: advanced 301 302 .keywords: communicator, create 303 304 .seealso: PetscSubcommDestroy() 305 @*/ 306 PetscErrorCode PetscSubcommCreate(MPI_Comm comm,PetscSubcomm *psubcomm) 307 { 308 PetscErrorCode ierr; 309 PetscMPIInt rank,size; 310 311 PetscFunctionBegin; 312 ierr = PetscNew(psubcomm);CHKERRQ(ierr); 313 314 /* set defaults */ 315 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 316 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 317 318 (*psubcomm)->parent = comm; 319 (*psubcomm)->dupparent = comm; 320 (*psubcomm)->child = PETSC_COMM_SELF; 321 (*psubcomm)->n = size; 322 (*psubcomm)->color = rank; 323 (*psubcomm)->subsize = NULL; 324 (*psubcomm)->type = PETSC_SUBCOMM_INTERLACED; 325 PetscFunctionReturn(0); 326 } 327 328 #undef __FUNCT__ 329 #define __FUNCT__ "PetscSubcommCreate_contiguous" 330 PetscErrorCode PetscSubcommCreate_contiguous(PetscSubcomm psubcomm) 331 { 332 PetscErrorCode ierr; 333 PetscMPIInt rank,size,*subsize,duprank=-1,subrank=-1; 334 PetscMPIInt np_subcomm,nleftover,i,color=-1,rankstart,nsubcomm=psubcomm->n; 335 MPI_Comm subcomm=0,dupcomm=0,comm=psubcomm->parent; 336 337 PetscFunctionBegin; 338 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 339 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 340 341 /* get size of each subcommunicator */ 342 ierr = PetscMalloc1(1+nsubcomm,&subsize);CHKERRQ(ierr); 343 344 np_subcomm = size/nsubcomm; 345 nleftover = size - nsubcomm*np_subcomm; 346 for (i=0; i<nsubcomm; i++) { 347 subsize[i] = np_subcomm; 348 if (i<nleftover) subsize[i]++; 349 } 350 351 /* get color and subrank of this proc */ 352 rankstart = 0; 353 for (i=0; i<nsubcomm; i++) { 354 if (rank >= rankstart && rank < rankstart+subsize[i]) { 355 color = i; 356 subrank = rank - rankstart; 357 duprank = rank; 358 break; 359 } else rankstart += subsize[i]; 360 } 361 362 ierr = MPI_Comm_split(comm,color,subrank,&subcomm);CHKERRQ(ierr); 363 364 /* create dupcomm with same size as comm, but its rank, duprank, maps subcomm's contiguously into dupcomm */ 365 ierr = MPI_Comm_split(comm,0,duprank,&dupcomm);CHKERRQ(ierr); 366 ierr = PetscCommDuplicate(dupcomm,&psubcomm->dupparent,NULL);CHKERRQ(ierr); 367 ierr = PetscCommDuplicate(subcomm,&psubcomm->child,NULL);CHKERRQ(ierr); 368 ierr = MPI_Comm_free(&dupcomm);CHKERRQ(ierr); 369 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 370 371 psubcomm->color = color; 372 psubcomm->subsize = subsize; 373 psubcomm->type = PETSC_SUBCOMM_CONTIGUOUS; 374 PetscFunctionReturn(0); 375 } 376 377 #undef __FUNCT__ 378 #define __FUNCT__ "PetscSubcommCreate_interlaced" 379 /* 380 Note: 381 In PCREDUNDANT, to avoid data scattering from subcomm back to original comm, we create subcommunicators 382 by iteratively taking a process into a subcommunicator. 383 Example: size=4, nsubcomm=(*psubcomm)->n=3 384 comm=(*psubcomm)->parent: 385 rank: [0] [1] [2] [3] 386 color: 0 1 2 0 387 388 subcomm=(*psubcomm)->comm: 389 subrank: [0] [0] [0] [1] 390 391 dupcomm=(*psubcomm)->dupparent: 392 duprank: [0] [2] [3] [1] 393 394 Here, subcomm[color = 0] has subsize=2, owns process [0] and [3] 395 subcomm[color = 1] has subsize=1, owns process [1] 396 subcomm[color = 2] has subsize=1, owns process [2] 397 dupcomm has same number of processes as comm, and its duprank maps 398 processes in subcomm contiguously into a 1d array: 399 duprank: [0] [1] [2] [3] 400 rank: [0] [3] [1] [2] 401 subcomm[0] subcomm[1] subcomm[2] 402 */ 403 404 PetscErrorCode PetscSubcommCreate_interlaced(PetscSubcomm psubcomm) 405 { 406 PetscErrorCode ierr; 407 PetscMPIInt rank,size,*subsize,duprank,subrank; 408 PetscMPIInt np_subcomm,nleftover,i,j,color,nsubcomm=psubcomm->n; 409 MPI_Comm subcomm=0,dupcomm=0,comm=psubcomm->parent; 410 411 PetscFunctionBegin; 412 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 413 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 414 415 /* get size of each subcommunicator */ 416 ierr = PetscMalloc1(1+nsubcomm,&subsize);CHKERRQ(ierr); 417 418 np_subcomm = size/nsubcomm; 419 nleftover = size - nsubcomm*np_subcomm; 420 for (i=0; i<nsubcomm; i++) { 421 subsize[i] = np_subcomm; 422 if (i<nleftover) subsize[i]++; 423 } 424 425 /* find color for this proc */ 426 color = rank%nsubcomm; 427 subrank = rank/nsubcomm; 428 429 ierr = MPI_Comm_split(comm,color,subrank,&subcomm);CHKERRQ(ierr); 430 431 j = 0; duprank = 0; 432 for (i=0; i<nsubcomm; i++) { 433 if (j == color) { 434 duprank += subrank; 435 break; 436 } 437 duprank += subsize[i]; j++; 438 } 439 440 /* create dupcomm with same size as comm, but its rank, duprank, maps subcomm's contiguously into dupcomm */ 441 ierr = MPI_Comm_split(comm,0,duprank,&dupcomm);CHKERRQ(ierr); 442 ierr = PetscCommDuplicate(dupcomm,&psubcomm->dupparent,NULL);CHKERRQ(ierr); 443 ierr = PetscCommDuplicate(subcomm,&psubcomm->child,NULL);CHKERRQ(ierr); 444 ierr = MPI_Comm_free(&dupcomm);CHKERRQ(ierr); 445 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 446 447 psubcomm->color = color; 448 psubcomm->subsize = subsize; 449 psubcomm->type = PETSC_SUBCOMM_INTERLACED; 450 PetscFunctionReturn(0); 451 } 452 453 454