1 2 /* 3 Provides utility routines for split MPI communicator. 4 */ 5 #include <petscsys.h> /*I "petscsys.h" I*/ 6 #include <petsc-private/threadcommimpl.h> /* Petsc_ThreadComm_keyval */ 7 #include <petscviewer.h> 8 9 const char *const PetscSubcommTypes[] = {"GENERAL","CONTIGUOUS","INTERLACED","PetscSubcommType","PETSC_SUBCOMM_",0}; 10 11 extern PetscErrorCode PetscSubcommCreate_contiguous(PetscSubcomm); 12 extern PetscErrorCode PetscSubcommCreate_interlaced(PetscSubcomm); 13 #undef __FUNCT__ 14 #define __FUNCT__ "PetscSubcommSetFromOptions" 15 PetscErrorCode PetscSubcommSetFromOptions(PetscSubcomm psubcomm) 16 { 17 PetscErrorCode ierr; 18 PetscInt type; 19 const char *psubcommTypes[3] = {"general","contiguous","interlaced"}; 20 PetscBool flg; 21 22 PetscFunctionBegin; 23 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"Must call PetscSubcommCreate firt"); 24 ierr = PetscOptionsEList("-psubcomm_type","PETSc subcommunicator","PetscSubcommSetType",psubcommTypes,3,psubcommTypes[2],&type,&flg);CHKERRQ(ierr); 25 if (flg && psubcomm->type != type) { 26 /* free old structures */ 27 ierr = PetscCommDestroy(&(psubcomm)->dupparent);CHKERRQ(ierr); 28 ierr = PetscCommDestroy(&(psubcomm)->comm);CHKERRQ(ierr); 29 ierr = PetscFree((psubcomm)->subsize);CHKERRQ(ierr); 30 switch (type) { 31 case 1: 32 ierr = PetscSubcommCreate_contiguous(psubcomm);CHKERRQ(ierr); 33 break; 34 case 2: 35 ierr = PetscSubcommCreate_interlaced(psubcomm);CHKERRQ(ierr); 36 break; 37 default: 38 SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"PetscSubcommType %D is not supported yet",type); 39 } 40 } 41 42 ierr = PetscOptionsHasName(NULL, "-psubcomm_view", &flg);CHKERRQ(ierr); 43 if (flg) { 44 ierr = PetscSubcommView(psubcomm,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 45 } 46 PetscFunctionReturn(0); 47 } 48 49 #undef __FUNCT__ 50 #define __FUNCT__ "PetscSubcommView" 51 PetscErrorCode PetscSubcommView(PetscSubcomm psubcomm,PetscViewer viewer) 52 { 53 PetscErrorCode ierr; 54 PetscBool iascii; 55 PetscViewerFormat format; 56 57 PetscFunctionBegin; 58 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 59 if (iascii) { 60 ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr); 61 if (format == PETSC_VIEWER_DEFAULT) { 62 MPI_Comm comm=psubcomm->parent; 63 PetscMPIInt rank,size,subsize,subrank,duprank; 64 65 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 66 ierr = PetscViewerASCIIPrintf(viewer,"PetscSubcomm type %s with total %D MPI processes:\n",PetscSubcommTypes[psubcomm->type],size);CHKERRQ(ierr); 67 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 68 ierr = MPI_Comm_size(psubcomm->comm,&subsize);CHKERRQ(ierr); 69 ierr = MPI_Comm_rank(psubcomm->comm,&subrank);CHKERRQ(ierr); 70 ierr = MPI_Comm_rank(psubcomm->dupparent,&duprank);CHKERRQ(ierr); 71 ierr = PetscSynchronizedPrintf(comm," [%D], color %D, sub-size %D, sub-rank %D, duprank %D\n",rank,psubcomm->color,subsize,subrank,duprank); 72 ierr = PetscSynchronizedFlush(comm);CHKERRQ(ierr); 73 } 74 } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not supported yet"); 75 PetscFunctionReturn(0); 76 } 77 78 #undef __FUNCT__ 79 #define __FUNCT__ "PetscSubcommSetNumber" 80 /*@C 81 PetscSubcommSetNumber - Set total number of subcommunicators. 82 83 Collective on MPI_Comm 84 85 Input Parameter: 86 + psubcomm - PetscSubcomm context 87 - nsubcomm - the total number of subcommunicators in psubcomm 88 89 Level: advanced 90 91 .keywords: communicator 92 93 .seealso: PetscSubcommCreate(),PetscSubcommDestroy(),PetscSubcommSetType(),PetscSubcommSetTypeGeneral() 94 @*/ 95 PetscErrorCode PetscSubcommSetNumber(PetscSubcomm psubcomm,PetscInt nsubcomm) 96 { 97 PetscErrorCode ierr; 98 MPI_Comm comm=psubcomm->parent; 99 PetscMPIInt rank,size; 100 101 PetscFunctionBegin; 102 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"PetscSubcomm is not created. Call PetscSubcommCreate() first"); 103 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 104 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 105 if (nsubcomm < 1 || nsubcomm > size) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Num of subcommunicators %D cannot be < 1 or > input comm size %D",nsubcomm,size); 106 107 psubcomm->n = nsubcomm; 108 PetscFunctionReturn(0); 109 } 110 111 #undef __FUNCT__ 112 #define __FUNCT__ "PetscSubcommSetType" 113 /*@C 114 PetscSubcommSetType - Set type of subcommunicators. 115 116 Collective on MPI_Comm 117 118 Input Parameter: 119 + psubcomm - PetscSubcomm context 120 - subcommtype - subcommunicator type, PETSC_SUBCOMM_CONTIGUOUS,PETSC_SUBCOMM_INTERLACED 121 122 Level: advanced 123 124 .keywords: communicator 125 126 .seealso: PetscSubcommCreate(),PetscSubcommDestroy(),PetscSubcommSetNumber(),PetscSubcommSetTypeGeneral() 127 @*/ 128 PetscErrorCode PetscSubcommSetType(PetscSubcomm psubcomm,PetscSubcommType subcommtype) 129 { 130 PetscErrorCode ierr; 131 132 PetscFunctionBegin; 133 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"PetscSubcomm is not created. Call PetscSubcommCreate()"); 134 if (psubcomm->n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of subcommunicators %D is incorrect. Call PetscSubcommSetNumber()",psubcomm->n); 135 136 if (subcommtype == PETSC_SUBCOMM_CONTIGUOUS) { 137 ierr = PetscSubcommCreate_contiguous(psubcomm);CHKERRQ(ierr); 138 } else if (subcommtype == PETSC_SUBCOMM_INTERLACED) { 139 ierr = PetscSubcommCreate_interlaced(psubcomm);CHKERRQ(ierr); 140 } else SETERRQ1(psubcomm->parent,PETSC_ERR_SUP,"PetscSubcommType %D is not supported yet",subcommtype); 141 PetscFunctionReturn(0); 142 } 143 144 #undef __FUNCT__ 145 #define __FUNCT__ "PetscSubcommSetTypeGeneral" 146 /*@C 147 PetscSubcommSetTypeGeneral - Set type of subcommunicators from user's specifications 148 149 Collective on MPI_Comm 150 151 Input Parameter: 152 + psubcomm - PetscSubcomm context 153 . color - control of subset assignment (nonnegative integer). Processes with the same color are in the same subcommunicator. 154 . subrank - rank in the subcommunicator 155 - duprank - rank in the dupparent (see PetscSubcomm) 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,PetscMPIInt duprank) 164 { 165 PetscErrorCode ierr; 166 MPI_Comm subcomm=0,dupcomm=0,comm=psubcomm->parent; 167 PetscMPIInt size; 168 169 PetscFunctionBegin; 170 if (!psubcomm) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NULL,"PetscSubcomm is not created. Call PetscSubcommCreate()"); 171 if (psubcomm->n < 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"number of subcommunicators %D is incorrect. Call PetscSubcommSetNumber()",psubcomm->n); 172 173 ierr = MPI_Comm_split(comm,color,subrank,&subcomm);CHKERRQ(ierr); 174 175 /* create dupcomm with same size as comm, but its rank, duprank, maps subcomm's contiguously into dupcomm 176 if duprank is not a valid number, then dupcomm is not created - not all applications require dupcomm! */ 177 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 178 if (duprank == PETSC_DECIDE) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"duprank==PETSC_DECIDE is not supported yet"); 179 else if (duprank >= 0 && duprank < size) { 180 ierr = MPI_Comm_split(comm,0,duprank,&dupcomm);CHKERRQ(ierr); 181 } 182 ierr = PetscCommDuplicate(dupcomm,&psubcomm->dupparent,NULL);CHKERRQ(ierr); 183 ierr = PetscCommDuplicate(subcomm,&psubcomm->comm,NULL);CHKERRQ(ierr); 184 ierr = MPI_Comm_free(&dupcomm);CHKERRQ(ierr); 185 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 186 187 psubcomm->color = color; 188 PetscFunctionReturn(0); 189 } 190 191 #undef __FUNCT__ 192 #define __FUNCT__ "PetscSubcommDestroy" 193 PetscErrorCode PetscSubcommDestroy(PetscSubcomm *psubcomm) 194 { 195 PetscErrorCode ierr; 196 197 PetscFunctionBegin; 198 if (!*psubcomm) PetscFunctionReturn(0); 199 ierr = PetscCommDestroy(&(*psubcomm)->dupparent);CHKERRQ(ierr); 200 ierr = PetscCommDestroy(&(*psubcomm)->comm);CHKERRQ(ierr); 201 ierr = PetscFree((*psubcomm)->subsize);CHKERRQ(ierr); 202 ierr = PetscFree((*psubcomm));CHKERRQ(ierr); 203 PetscFunctionReturn(0); 204 } 205 206 #undef __FUNCT__ 207 #define __FUNCT__ "PetscSubcommCreate" 208 /*@C 209 PetscSubcommCreate - Create a PetscSubcomm context. 210 211 Collective on MPI_Comm 212 213 Input Parameter: 214 . comm - MPI communicator 215 216 Output Parameter: 217 . psubcomm - location to store the PetscSubcomm context 218 219 Level: advanced 220 221 .keywords: communicator, create 222 223 .seealso: PetscSubcommDestroy() 224 @*/ 225 PetscErrorCode PetscSubcommCreate(MPI_Comm comm,PetscSubcomm *psubcomm) 226 { 227 PetscErrorCode ierr; 228 PetscMPIInt rank,size; 229 230 PetscFunctionBegin; 231 ierr = PetscNew(struct _n_PetscSubcomm,psubcomm);CHKERRQ(ierr); 232 233 /* set defaults */ 234 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 235 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 236 237 (*psubcomm)->parent = comm; 238 (*psubcomm)->dupparent = comm; 239 (*psubcomm)->comm = PETSC_COMM_SELF; 240 (*psubcomm)->n = size; 241 (*psubcomm)->color = rank; 242 (*psubcomm)->subsize = NULL; 243 (*psubcomm)->type = PETSC_SUBCOMM_INTERLACED; 244 PetscFunctionReturn(0); 245 } 246 247 #undef __FUNCT__ 248 #define __FUNCT__ "PetscSubcommCreate_contiguous" 249 PetscErrorCode PetscSubcommCreate_contiguous(PetscSubcomm psubcomm) 250 { 251 PetscErrorCode ierr; 252 PetscMPIInt rank,size,*subsize,duprank=-1,subrank=-1; 253 PetscInt np_subcomm,nleftover,i,color=-1,rankstart,nsubcomm=psubcomm->n; 254 MPI_Comm subcomm=0,dupcomm=0,comm=psubcomm->parent; 255 256 PetscFunctionBegin; 257 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 258 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 259 260 /* get size of each subcommunicator */ 261 ierr = PetscMalloc((1+nsubcomm)*sizeof(PetscMPIInt),&subsize);CHKERRQ(ierr); 262 263 np_subcomm = size/nsubcomm; 264 nleftover = size - nsubcomm*np_subcomm; 265 for (i=0; i<nsubcomm; i++) { 266 subsize[i] = np_subcomm; 267 if (i<nleftover) subsize[i]++; 268 } 269 270 /* get color and subrank of this proc */ 271 rankstart = 0; 272 for (i=0; i<nsubcomm; i++) { 273 if (rank >= rankstart && rank < rankstart+subsize[i]) { 274 color = i; 275 subrank = rank - rankstart; 276 duprank = rank; 277 break; 278 } else rankstart += subsize[i]; 279 } 280 281 ierr = MPI_Comm_split(comm,color,subrank,&subcomm);CHKERRQ(ierr); 282 283 /* create dupcomm with same size as comm, but its rank, duprank, maps subcomm's contiguously into dupcomm */ 284 ierr = MPI_Comm_split(comm,0,duprank,&dupcomm);CHKERRQ(ierr); 285 { 286 PetscThreadComm tcomm; 287 ierr = PetscCommGetThreadComm(comm,&tcomm);CHKERRQ(ierr); 288 ierr = MPI_Attr_put(dupcomm,Petsc_ThreadComm_keyval,tcomm);CHKERRQ(ierr); 289 tcomm->refct++; 290 ierr = MPI_Attr_put(subcomm,Petsc_ThreadComm_keyval,tcomm);CHKERRQ(ierr); 291 tcomm->refct++; 292 } 293 ierr = PetscCommDuplicate(dupcomm,&psubcomm->dupparent,NULL);CHKERRQ(ierr); 294 ierr = PetscCommDuplicate(subcomm,&psubcomm->comm,NULL);CHKERRQ(ierr); 295 ierr = MPI_Comm_free(&dupcomm);CHKERRQ(ierr); 296 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 297 298 psubcomm->color = color; 299 psubcomm->subsize = subsize; 300 psubcomm->type = PETSC_SUBCOMM_CONTIGUOUS; 301 PetscFunctionReturn(0); 302 } 303 304 #undef __FUNCT__ 305 #define __FUNCT__ "PetscSubcommCreate_interlaced" 306 /* 307 Note: 308 In PCREDUNDANT, to avoid data scattering from subcomm back to original comm, we create subcommunicators 309 by iteratively taking a process into a subcommunicator. 310 Example: size=4, nsubcomm=(*psubcomm)->n=3 311 comm=(*psubcomm)->parent: 312 rank: [0] [1] [2] [3] 313 color: 0 1 2 0 314 315 subcomm=(*psubcomm)->comm: 316 subrank: [0] [0] [0] [1] 317 318 dupcomm=(*psubcomm)->dupparent: 319 duprank: [0] [2] [3] [1] 320 321 Here, subcomm[color = 0] has subsize=2, owns process [0] and [3] 322 subcomm[color = 1] has subsize=1, owns process [1] 323 subcomm[color = 2] has subsize=1, owns process [2] 324 dupcomm has same number of processes as comm, and its duprank maps 325 processes in subcomm contiguously into a 1d array: 326 duprank: [0] [1] [2] [3] 327 rank: [0] [3] [1] [2] 328 subcomm[0] subcomm[1] subcomm[2] 329 */ 330 331 PetscErrorCode PetscSubcommCreate_interlaced(PetscSubcomm psubcomm) 332 { 333 PetscErrorCode ierr; 334 PetscMPIInt rank,size,*subsize,duprank,subrank; 335 PetscInt np_subcomm,nleftover,i,j,color,nsubcomm=psubcomm->n; 336 MPI_Comm subcomm=0,dupcomm=0,comm=psubcomm->parent; 337 338 PetscFunctionBegin; 339 ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr); 340 ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr); 341 342 /* get size of each subcommunicator */ 343 ierr = PetscMalloc((1+nsubcomm)*sizeof(PetscMPIInt),&subsize);CHKERRQ(ierr); 344 345 np_subcomm = size/nsubcomm; 346 nleftover = size - nsubcomm*np_subcomm; 347 for (i=0; i<nsubcomm; i++) { 348 subsize[i] = np_subcomm; 349 if (i<nleftover) subsize[i]++; 350 } 351 352 /* find color for this proc */ 353 color = rank%nsubcomm; 354 subrank = rank/nsubcomm; 355 356 ierr = MPI_Comm_split(comm,color,subrank,&subcomm);CHKERRQ(ierr); 357 358 j = 0; duprank = 0; 359 for (i=0; i<nsubcomm; i++) { 360 if (j == color) { 361 duprank += subrank; 362 break; 363 } 364 duprank += subsize[i]; j++; 365 } 366 367 /* create dupcomm with same size as comm, but its rank, duprank, maps subcomm's contiguously into dupcomm */ 368 ierr = MPI_Comm_split(comm,0,duprank,&dupcomm);CHKERRQ(ierr); 369 { 370 PetscThreadComm tcomm; 371 ierr = PetscCommGetThreadComm(comm,&tcomm);CHKERRQ(ierr); 372 ierr = MPI_Attr_put(dupcomm,Petsc_ThreadComm_keyval,tcomm);CHKERRQ(ierr); 373 tcomm->refct++; 374 ierr = MPI_Attr_put(subcomm,Petsc_ThreadComm_keyval,tcomm);CHKERRQ(ierr); 375 tcomm->refct++; 376 } 377 ierr = PetscCommDuplicate(dupcomm,&psubcomm->dupparent,NULL);CHKERRQ(ierr); 378 ierr = PetscCommDuplicate(subcomm,&psubcomm->comm,NULL);CHKERRQ(ierr); 379 ierr = MPI_Comm_free(&dupcomm);CHKERRQ(ierr); 380 ierr = MPI_Comm_free(&subcomm);CHKERRQ(ierr); 381 382 psubcomm->color = color; 383 psubcomm->subsize = subsize; 384 psubcomm->type = PETSC_SUBCOMM_INTERLACED; 385 PetscFunctionReturn(0); 386 } 387 388 389