1 #include <petscvec.h> 2 #include <petsc/private/partitionerimpl.h> /*I "petscpartitioner.h" I*/ 3 4 typedef struct { 5 PetscBool useGrid; /* Flag to use a grid layout */ 6 PetscInt gridDim; /* The grid dimension */ 7 PetscInt nodeGrid[3]; /* Dimension of node grid */ 8 PetscInt processGrid[3]; /* Dimension of local process grid on each node */ 9 } PetscPartitioner_Simple; 10 11 static PetscErrorCode PetscPartitionerDestroy_Simple(PetscPartitioner part) 12 { 13 PetscFunctionBegin; 14 PetscCall(PetscFree(part->data)); 15 PetscFunctionReturn(PETSC_SUCCESS); 16 } 17 18 static PetscErrorCode PetscPartitionerSetFromOptions_Simple(PetscPartitioner part, PetscOptionItems PetscOptionsObject) 19 { 20 PetscPartitioner_Simple *p = (PetscPartitioner_Simple *)part->data; 21 PetscInt num, i; 22 PetscBool flg; 23 24 PetscFunctionBegin; 25 for (i = 0; i < 3; ++i) p->processGrid[i] = p->nodeGrid[i] = 1; 26 PetscOptionsHeadBegin(PetscOptionsObject, "PetscPartitioner Simple Options"); 27 num = 3; 28 PetscCall(PetscOptionsIntArray("-petscpartitioner_simple_node_grid", "Number of nodes in each dimension", "", p->nodeGrid, &num, &flg)); 29 if (flg) { 30 p->useGrid = PETSC_TRUE; 31 p->gridDim = num; 32 } 33 num = 3; 34 PetscCall(PetscOptionsIntArray("-petscpartitioner_simple_process_grid", "Number of local processes in each dimension for a given node", "", p->processGrid, &num, &flg)); 35 if (flg) { 36 p->useGrid = PETSC_TRUE; 37 if (p->gridDim < 0) p->gridDim = num; 38 else PetscCheck(p->gridDim == num, PetscObjectComm((PetscObject)part), PETSC_ERR_ARG_INCOMP, "Process grid dimension %" PetscInt_FMT " != %" PetscInt_FMT " node grid dimension", num, p->gridDim); 39 } 40 PetscOptionsHeadEnd(); 41 PetscFunctionReturn(PETSC_SUCCESS); 42 } 43 44 static PetscErrorCode PetscPartitionerPartition_Simple_Grid(PetscPartitioner part, PetscInt nparts, PetscInt numVertices, PetscInt start[], PetscInt adjacency[], PetscSection vertSection, PetscSection targetSection, PetscSection partSection, IS *partition) 45 { 46 PetscPartitioner_Simple *p = (PetscPartitioner_Simple *)part->data; 47 const PetscInt *nodes = p->nodeGrid; 48 const PetscInt *procs = p->processGrid; 49 PetscInt *cellproc, *offsets, cells[3] = {1, 1, 1}, pcells[3] = {1, 1, 1}; 50 PetscInt Np = 1, Nr, np, nk, nj, ni, pk, pj, pi, ck, cj, ci, i; 51 MPI_Comm comm; 52 PetscMPIInt size; 53 54 PetscFunctionBegin; 55 if (vertSection) PetscCall(PetscInfo(part, "PETSCPARTITIONERSIMPLE ignores vertex weights when using grid partition\n")); 56 if (targetSection) PetscCall(PetscInfo(part, "PETSCPARTITIONERSIMPLE ignores partition weights when using grid partition\n")); 57 PetscCall(PetscObjectGetComm((PetscObject)part, &comm)); 58 PetscCallMPI(MPI_Comm_size(comm, &size)); 59 /* Check grid */ 60 for (i = 0; i < 3; ++i) Np *= nodes[i] * procs[i]; 61 PetscCheck(nparts == Np, comm, PETSC_ERR_ARG_INCOMP, "Number of partitions %" PetscInt_FMT " != %" PetscInt_FMT " grid size", nparts, Np); 62 PetscCheck(nparts == size, comm, PETSC_ERR_ARG_INCOMP, "Number of partitions %" PetscInt_FMT " != %d processes", nparts, size); 63 PetscCheck(numVertices % nparts == 0, comm, PETSC_ERR_ARG_INCOMP, "Number of cells %" PetscInt_FMT " is not divisible by number of partitions %" PetscInt_FMT, numVertices, nparts); 64 for (i = 0; i < p->gridDim; ++i) cells[i] = nodes[i] * procs[i]; 65 Nr = numVertices / nparts; 66 while (Nr > 1) { 67 for (i = 0; i < p->gridDim; ++i) { 68 cells[i] *= 2; 69 Nr /= 2; 70 } 71 } 72 PetscCheck(!numVertices || Nr == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Odd number of cells %" PetscInt_FMT ". Must be nprocs*2^k", numVertices); 73 for (i = 0; i < p->gridDim; ++i) { 74 PetscCheck(cells[i] % (nodes[i] * procs[i]) == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "dir %" PetscInt_FMT ". Number of cells (%" PetscInt_FMT ") mod number of processors %" PetscInt_FMT, i, cells[i], nodes[i] * procs[i]); 75 pcells[i] = cells[i] / (nodes[i] * procs[i]); 76 } 77 /* Compute sizes */ 78 for (np = 0; np < nparts; ++np) PetscCall(PetscSectionSetDof(partSection, np, numVertices / nparts)); 79 PetscCall(PetscSectionSetUp(partSection)); 80 PetscCall(PetscCalloc1(nparts, &offsets)); 81 for (np = 0; np < nparts; ++np) PetscCall(PetscSectionGetOffset(partSection, np, &offsets[np])); 82 if (!numVertices) pcells[0] = pcells[1] = pcells[2] = 0; 83 /* Compute partition */ 84 PetscCall(PetscMalloc1(numVertices, &cellproc)); 85 for (nk = 0; nk < nodes[2]; ++nk) { 86 for (nj = 0; nj < nodes[1]; ++nj) { 87 for (ni = 0; ni < nodes[0]; ++ni) { 88 const PetscInt nid = (nk * nodes[1] + nj) * nodes[0] + ni; 89 90 for (pk = 0; pk < procs[2]; ++pk) { 91 for (pj = 0; pj < procs[1]; ++pj) { 92 for (pi = 0; pi < procs[0]; ++pi) { 93 const PetscInt pid = ((nid * procs[2] + pk) * procs[1] + pj) * procs[0] + pi; 94 95 /* Assume that cells are originally numbered lexicographically */ 96 for (ck = 0; ck < pcells[2]; ++ck) { 97 for (cj = 0; cj < pcells[1]; ++cj) { 98 for (ci = 0; ci < pcells[0]; ++ci) { 99 const PetscInt cid = (((nk * procs[2] + pk) * pcells[2] + ck) * cells[1] + ((nj * procs[1] + pj) * pcells[1] + cj)) * cells[0] + (ni * procs[0] + pi) * pcells[0] + ci; 100 101 cellproc[offsets[pid]++] = cid; 102 } 103 } 104 } 105 } 106 } 107 } 108 } 109 } 110 } 111 for (np = 1; np < nparts; ++np) PetscCheck(offsets[np] - offsets[np - 1] == numVertices / nparts, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Offset %" PetscInt_FMT " != %" PetscInt_FMT " partition size", offsets[np], numVertices / nparts); 112 PetscCall(PetscFree(offsets)); 113 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, numVertices, cellproc, PETSC_OWN_POINTER, partition)); 114 PetscFunctionReturn(PETSC_SUCCESS); 115 } 116 117 static PetscErrorCode PetscPartitionerPartition_Simple(PetscPartitioner part, PetscInt nparts, PetscInt numVertices, PetscInt start[], PetscInt adjacency[], PetscSection vertSection, PetscSection edgeSection, PetscSection targetSection, PetscSection partSection, IS *partition) 118 { 119 PetscPartitioner_Simple *p = (PetscPartitioner_Simple *)part->data; 120 MPI_Comm comm; 121 PetscInt np, *tpwgts = NULL, sumw = 0, numVerticesGlobal = 0; 122 PetscMPIInt size; 123 124 PetscFunctionBegin; 125 if (p->useGrid) { 126 PetscCall(PetscPartitionerPartition_Simple_Grid(part, nparts, numVertices, start, adjacency, vertSection, targetSection, partSection, partition)); 127 PetscFunctionReturn(PETSC_SUCCESS); 128 } 129 if (vertSection) PetscCall(PetscInfo(part, "PETSCPARTITIONERSIMPLE ignores vertex weights\n")); 130 PetscCall(PetscObjectGetComm((PetscObject)part, &comm)); 131 PetscCallMPI(MPI_Comm_size(comm, &size)); 132 if (targetSection) { 133 PetscCallMPI(MPIU_Allreduce(&numVertices, &numVerticesGlobal, 1, MPIU_INT, MPI_SUM, comm)); 134 PetscCall(PetscCalloc1(nparts, &tpwgts)); 135 for (np = 0; np < nparts; ++np) { 136 PetscCall(PetscSectionGetDof(targetSection, np, &tpwgts[np])); 137 sumw += tpwgts[np]; 138 } 139 if (sumw) { 140 PetscInt m, mp; 141 for (np = 0; np < nparts; ++np) tpwgts[np] = (tpwgts[np] * numVerticesGlobal) / sumw; 142 for (np = 0, m = -1, mp = 0, sumw = 0; np < nparts; ++np) { 143 if (m < tpwgts[np]) { 144 m = tpwgts[np]; 145 mp = np; 146 } 147 sumw += tpwgts[np]; 148 } 149 if (sumw != numVerticesGlobal) tpwgts[mp] += numVerticesGlobal - sumw; 150 } 151 if (!sumw) PetscCall(PetscFree(tpwgts)); 152 } 153 154 PetscCall(ISCreateStride(PETSC_COMM_SELF, numVertices, 0, 1, partition)); 155 if (size == 1) { 156 if (tpwgts) { 157 for (np = 0; np < nparts; ++np) PetscCall(PetscSectionSetDof(partSection, np, tpwgts[np])); 158 } else { 159 for (np = 0; np < nparts; ++np) PetscCall(PetscSectionSetDof(partSection, np, numVertices / nparts + ((numVertices % nparts) > np))); 160 } 161 } else { 162 if (tpwgts) { 163 Vec v; 164 PetscScalar *array; 165 PetscInt st, j; 166 PetscMPIInt rank; 167 168 PetscCall(VecCreate(comm, &v)); 169 PetscCall(VecSetSizes(v, numVertices, numVerticesGlobal)); 170 PetscCall(VecSetType(v, VECSTANDARD)); 171 PetscCallMPI(MPI_Comm_rank(comm, &rank)); 172 for (np = 0, st = 0; np < nparts; ++np) { 173 if (rank == np || (rank == size - 1 && size < nparts && np >= size)) { 174 for (j = 0; j < tpwgts[np]; j++) PetscCall(VecSetValue(v, st + j, np, INSERT_VALUES)); 175 } 176 st += tpwgts[np]; 177 } 178 PetscCall(VecAssemblyBegin(v)); 179 PetscCall(VecAssemblyEnd(v)); 180 PetscCall(VecGetArray(v, &array)); 181 for (j = 0; j < numVertices; ++j) PetscCall(PetscSectionAddDof(partSection, PetscRealPart(array[j]), 1)); 182 PetscCall(VecRestoreArray(v, &array)); 183 PetscCall(VecDestroy(&v)); 184 } else { 185 PetscMPIInt rank; 186 PetscInt nvGlobal, *offsets, myFirst, myLast; 187 188 PetscCall(PetscMalloc1(size + 1, &offsets)); 189 offsets[0] = 0; 190 PetscCallMPI(MPI_Allgather(&numVertices, 1, MPIU_INT, &offsets[1], 1, MPIU_INT, comm)); 191 for (np = 2; np <= size; np++) offsets[np] += offsets[np - 1]; 192 nvGlobal = offsets[size]; 193 PetscCallMPI(MPI_Comm_rank(comm, &rank)); 194 myFirst = offsets[rank]; 195 myLast = offsets[rank + 1] - 1; 196 PetscCall(PetscFree(offsets)); 197 if (numVertices) { 198 PetscInt firstPart = 0, firstLargePart = 0; 199 PetscInt lastPart = 0, lastLargePart = 0; 200 PetscInt rem = nvGlobal % nparts; 201 PetscInt pSmall = nvGlobal / nparts; 202 PetscInt pBig = nvGlobal / nparts + 1; 203 204 if (rem) { 205 firstLargePart = myFirst / pBig; 206 lastLargePart = myLast / pBig; 207 208 if (firstLargePart < rem) { 209 firstPart = firstLargePart; 210 } else { 211 firstPart = rem + (myFirst - (rem * pBig)) / pSmall; 212 } 213 if (lastLargePart < rem) { 214 lastPart = lastLargePart; 215 } else { 216 lastPart = rem + (myLast - (rem * pBig)) / pSmall; 217 } 218 } else { 219 firstPart = myFirst / (nvGlobal / nparts); 220 lastPart = myLast / (nvGlobal / nparts); 221 } 222 223 for (np = firstPart; np <= lastPart; np++) { 224 PetscInt PartStart = np * (nvGlobal / nparts) + PetscMin(nvGlobal % nparts, np); 225 PetscInt PartEnd = (np + 1) * (nvGlobal / nparts) + PetscMin(nvGlobal % nparts, np + 1); 226 227 PartStart = PetscMax(PartStart, myFirst); 228 PartEnd = PetscMin(PartEnd, myLast + 1); 229 PetscCall(PetscSectionSetDof(partSection, np, PartEnd - PartStart)); 230 } 231 } 232 } 233 } 234 PetscCall(PetscFree(tpwgts)); 235 PetscFunctionReturn(PETSC_SUCCESS); 236 } 237 238 static PetscErrorCode PetscPartitionerInitialize_Simple(PetscPartitioner part) 239 { 240 PetscFunctionBegin; 241 part->noGraph = PETSC_TRUE; 242 part->ops->setfromoptions = PetscPartitionerSetFromOptions_Simple; 243 part->ops->destroy = PetscPartitionerDestroy_Simple; 244 part->ops->partition = PetscPartitionerPartition_Simple; 245 PetscFunctionReturn(PETSC_SUCCESS); 246 } 247 248 /*MC 249 PETSCPARTITIONERSIMPLE = "simple" - A PetscPartitioner object 250 251 Level: intermediate 252 253 .seealso: `PetscPartitionerType`, `PetscPartitionerCreate()`, `PetscPartitionerSetType()` 254 M*/ 255 256 PETSC_EXTERN PetscErrorCode PetscPartitionerCreate_Simple(PetscPartitioner part) 257 { 258 PetscPartitioner_Simple *p; 259 260 PetscFunctionBegin; 261 PetscValidHeaderSpecific(part, PETSCPARTITIONER_CLASSID, 1); 262 PetscCall(PetscNew(&p)); 263 p->gridDim = -1; 264 part->data = p; 265 266 PetscCall(PetscPartitionerInitialize_Simple(part)); 267 PetscFunctionReturn(PETSC_SUCCESS); 268 } 269