1 #include <../src/mat/impls/baij/mpi/mpibaij.h> 2 3 PetscErrorCode MatGetMultiProcBlock_MPIBAIJ(Mat mat, MPI_Comm subComm, MatReuse scall,Mat *subMat) 4 { 5 Mat_MPIBAIJ *aij = (Mat_MPIBAIJ*)mat->data; 6 Mat_SeqBAIJ *aijB = (Mat_SeqBAIJ*)aij->B->data; 7 PetscMPIInt commRank,subCommSize,subCommRank; 8 PetscMPIInt *commRankMap,subRank,rank,commsize; 9 PetscInt *garrayCMap,col,i,j,*nnz,newRow,newCol,*newbRow,*newbCol,k,k1; 10 PetscInt bs=mat->rmap->bs; 11 PetscScalar *vals,*aijBvals; 12 13 PetscFunctionBegin; 14 PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)mat),&commsize)); 15 PetscCallMPI(MPI_Comm_size(subComm,&subCommSize)); 16 17 /* create subMat object with the relevant layout */ 18 if (scall == MAT_INITIAL_MATRIX) { 19 PetscCall(MatCreate(subComm,subMat)); 20 PetscCall(MatSetType(*subMat,MATMPIBAIJ)); 21 PetscCall(MatSetSizes(*subMat,mat->rmap->n,mat->cmap->n,PETSC_DECIDE,PETSC_DECIDE)); 22 PetscCall(MatSetBlockSizes(*subMat,mat->rmap->bs,mat->cmap->bs)); 23 24 /* need to setup rmap and cmap before Preallocation */ 25 PetscCall(PetscLayoutSetBlockSize((*subMat)->rmap,mat->rmap->bs)); 26 PetscCall(PetscLayoutSetBlockSize((*subMat)->cmap,mat->cmap->bs)); 27 PetscCall(PetscLayoutSetUp((*subMat)->rmap)); 28 PetscCall(PetscLayoutSetUp((*subMat)->cmap)); 29 } 30 31 /* create a map of comm_rank from subComm to comm - should commRankMap and garrayCMap be kept for reused? */ 32 PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)mat),&commRank)); 33 PetscCallMPI(MPI_Comm_rank(subComm,&subCommRank)); 34 PetscCall(PetscMalloc1(subCommSize,&commRankMap)); 35 PetscCallMPI(MPI_Allgather(&commRank,1,MPI_INT,commRankMap,1,MPI_INT,subComm)); 36 37 /* Traverse garray and identify blocked column indices [of offdiag mat] that 38 should be discarded. For the ones not discarded, store the newCol+1 39 value in garrayCMap */ 40 PetscCall(PetscCalloc1(aij->B->cmap->n/bs,&garrayCMap)); 41 for (i=0; i<aij->B->cmap->n/bs; i++) { 42 col = aij->garray[i]; /* blocked column index */ 43 for (subRank=0; subRank<subCommSize; subRank++) { 44 rank = commRankMap[subRank]; 45 if ((col >= mat->cmap->range[rank]/bs) && (col < mat->cmap->range[rank+1]/bs)) { 46 garrayCMap[i] = (((*subMat)->cmap->range[subRank]- mat->cmap->range[rank])/bs + col + 1); 47 break; 48 } 49 } 50 } 51 52 if (scall == MAT_INITIAL_MATRIX) { 53 /* Now compute preallocation for the offdiag mat */ 54 PetscCall(PetscCalloc1(aij->B->rmap->n/bs,&nnz)); 55 for (i=0; i<aij->B->rmap->n/bs; i++) { 56 for (j=aijB->i[i]; j<aijB->i[i+1]; j++) { 57 if (garrayCMap[aijB->j[j]]) nnz[i]++; 58 } 59 } 60 PetscCall(MatMPIBAIJSetPreallocation(*(subMat),bs,0,NULL,0,nnz)); 61 62 /* reuse diag block with the new submat */ 63 PetscCall(MatDestroy(&((Mat_MPIBAIJ*)((*subMat)->data))->A)); 64 65 ((Mat_MPIBAIJ*)((*subMat)->data))->A = aij->A; 66 67 PetscCall(PetscObjectReference((PetscObject)aij->A)); 68 } else if (((Mat_MPIBAIJ*)(*subMat)->data)->A != aij->A) { 69 PetscObject obj = (PetscObject)((Mat_MPIBAIJ*)((*subMat)->data))->A; 70 71 PetscCall(PetscObjectReference((PetscObject)obj)); 72 73 ((Mat_MPIBAIJ*)((*subMat)->data))->A = aij->A; 74 75 PetscCall(PetscObjectReference((PetscObject)aij->A)); 76 } 77 78 /* Now traverse aij->B and insert values into subMat */ 79 PetscCall(PetscMalloc3(bs,&newbRow,bs,&newbCol,bs*bs,&vals)); 80 for (i=0; i<aij->B->rmap->n/bs; i++) { 81 newRow = (*subMat)->rmap->range[subCommRank] + i*bs; 82 for (j=aijB->i[i]; j<aijB->i[i+1]; j++) { 83 newCol = garrayCMap[aijB->j[j]]; 84 if (newCol) { 85 newCol--; /* remove the increment */ 86 newCol *= bs; 87 for (k=0; k<bs; k++) { 88 newbRow[k] = newRow + k; 89 newbCol[k] = newCol + k; 90 } 91 /* copy column-oriented aijB->a into row-oriented vals */ 92 aijBvals = aijB->a + j*bs*bs; 93 for (k1=0; k1<bs; k1++) { 94 for (k=0; k<bs; k++) { 95 vals[k1+k*bs] = *aijBvals++; 96 } 97 } 98 PetscCall(MatSetValues(*subMat,bs,newbRow,bs,newbCol,vals,INSERT_VALUES)); 99 } 100 } 101 } 102 PetscCall(MatAssemblyBegin(*subMat,MAT_FINAL_ASSEMBLY)); 103 PetscCall(MatAssemblyEnd(*subMat,MAT_FINAL_ASSEMBLY)); 104 105 /* deallocate temporary data */ 106 PetscCall(PetscFree3(newbRow,newbCol,vals)); 107 PetscCall(PetscFree(commRankMap)); 108 PetscCall(PetscFree(garrayCMap)); 109 if (scall == MAT_INITIAL_MATRIX) { 110 PetscCall(PetscFree(nnz)); 111 } 112 PetscFunctionReturn(0); 113 } 114