1 /* 2 GAMG geometric-algebric multigrid PC - Mark Adams 2011 3 */ 4 #include <petsc/private/matimpl.h> 5 #include <../src/ksp/pc/impls/gamg/gamg.h> /*I "petscpc.h" I*/ 6 #include <petsc/private/kspimpl.h> 7 8 /* -------------------------------------------------------------------------- */ 9 /* 10 PCGAMGGetDataWithGhosts - Get array of local + ghost data with local data 11 hacks into Mat MPIAIJ so this must have size > 1 12 13 Input Parameter: 14 . Gmat - MPIAIJ matrix for scatters 15 . data_sz - number of data terms per node (# cols in output) 16 . data_in[nloc*data_sz] - column oriented local data 17 18 Output Parameter: 19 . a_stride - number of rows of output (locals+ghosts) 20 . a_data_out[stride*data_sz] - output data with ghosts 21 22 */ 23 PetscErrorCode PCGAMGGetDataWithGhosts(Mat Gmat,PetscInt data_sz,PetscReal data_in[],PetscInt *a_stride,PetscReal **a_data_out) 24 { 25 Vec tmp_crds; 26 Mat_MPIAIJ *mpimat = (Mat_MPIAIJ*)Gmat->data; 27 PetscInt nnodes,num_ghosts,dir,kk,jj,my0,Iend,nloc; 28 PetscScalar *data_arr; 29 PetscReal *datas; 30 PetscBool isMPIAIJ; 31 32 PetscFunctionBegin; 33 PetscCall(PetscObjectBaseTypeCompare((PetscObject)Gmat, MATMPIAIJ, &isMPIAIJ)); 34 PetscCall(MatGetOwnershipRange(Gmat, &my0, &Iend)); 35 nloc = Iend - my0; 36 PetscCall(VecGetLocalSize(mpimat->lvec, &num_ghosts)); 37 nnodes = num_ghosts + nloc; 38 *a_stride = nnodes; 39 PetscCall(MatCreateVecs(Gmat, &tmp_crds, NULL)); 40 41 PetscCall(PetscMalloc1(data_sz*nnodes, &datas)); 42 for (dir=0; dir<data_sz; dir++) { 43 /* set local, and global */ 44 for (kk=0; kk<nloc; kk++) { 45 PetscInt gid = my0 + kk; 46 PetscScalar crd = (PetscScalar)data_in[dir*nloc + kk]; /* col oriented */ 47 datas[dir*nnodes + kk] = PetscRealPart(crd); // get local part now 48 49 PetscCall(VecSetValues(tmp_crds, 1, &gid, &crd, INSERT_VALUES)); 50 } 51 PetscCall(VecAssemblyBegin(tmp_crds)); 52 PetscCall(VecAssemblyEnd(tmp_crds)); 53 /* scatter / gather ghost data and add to end of output data */ 54 PetscCall(VecScatterBegin(mpimat->Mvctx,tmp_crds,mpimat->lvec,INSERT_VALUES,SCATTER_FORWARD)); 55 PetscCall(VecScatterEnd(mpimat->Mvctx,tmp_crds,mpimat->lvec,INSERT_VALUES,SCATTER_FORWARD)); 56 PetscCall(VecGetArray(mpimat->lvec, &data_arr)); 57 for (kk=nloc,jj=0;jj<num_ghosts;kk++,jj++) datas[dir*nnodes + kk] = PetscRealPart(data_arr[jj]); 58 PetscCall(VecRestoreArray(mpimat->lvec, &data_arr)); 59 } 60 PetscCall(VecDestroy(&tmp_crds)); 61 *a_data_out = datas; 62 PetscFunctionReturn(0); 63 } 64 65 PetscErrorCode PCGAMGHashTableCreate(PetscInt a_size, PCGAMGHashTable *a_tab) 66 { 67 PetscInt kk; 68 69 PetscFunctionBegin; 70 a_tab->size = a_size; 71 PetscCall(PetscMalloc2(a_size, &a_tab->table,a_size, &a_tab->data)); 72 for (kk=0; kk<a_size; kk++) a_tab->table[kk] = -1; 73 PetscFunctionReturn(0); 74 } 75 76 PetscErrorCode PCGAMGHashTableDestroy(PCGAMGHashTable *a_tab) 77 { 78 PetscFunctionBegin; 79 PetscCall(PetscFree2(a_tab->table,a_tab->data)); 80 PetscFunctionReturn(0); 81 } 82 83 PetscErrorCode PCGAMGHashTableAdd(PCGAMGHashTable *a_tab, PetscInt a_key, PetscInt a_data) 84 { 85 PetscInt kk,idx; 86 87 PetscFunctionBegin; 88 PetscCheck(a_key>=0,PETSC_COMM_SELF,PETSC_ERR_USER,"Negative key %" PetscInt_FMT ".",a_key); 89 for (kk = 0, idx = GAMG_HASH(a_key); kk < a_tab->size; kk++, idx = (idx==(a_tab->size-1)) ? 0 : idx + 1) { 90 if (a_tab->table[idx] == a_key) { 91 /* exists */ 92 a_tab->data[idx] = a_data; 93 break; 94 } else if (a_tab->table[idx] == -1) { 95 /* add */ 96 a_tab->table[idx] = a_key; 97 a_tab->data[idx] = a_data; 98 break; 99 } 100 } 101 if (kk==a_tab->size) { 102 /* this is not to efficient, waiting until completely full */ 103 PetscInt oldsize = a_tab->size, new_size = 2*a_tab->size + 5, *oldtable = a_tab->table, *olddata = a_tab->data; 104 105 a_tab->size = new_size; 106 PetscCall(PetscMalloc2(a_tab->size, &a_tab->table,a_tab->size, &a_tab->data)); 107 for (kk=0;kk<a_tab->size;kk++) a_tab->table[kk] = -1; 108 for (kk=0;kk<oldsize;kk++) { 109 if (oldtable[kk] != -1) { 110 PetscCall(PCGAMGHashTableAdd(a_tab, oldtable[kk], olddata[kk])); 111 } 112 } 113 PetscCall(PetscFree2(oldtable,olddata)); 114 PetscCall(PCGAMGHashTableAdd(a_tab, a_key, a_data)); 115 } 116 PetscFunctionReturn(0); 117 } 118