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