1 static char help[] = "Compare parallel partitioning strategies using matrix graphs\n\n"; 2 3 #include <petscmat.h> 4 5 int main(int argc, char **args) 6 { 7 MatPartitioning part; 8 IS partis; 9 Mat A = NULL; 10 PetscInt max = -1; 11 PetscInt min = -1; 12 PetscReal balance = 0.0; 13 const PetscInt *ranges = NULL; 14 char filein[PETSC_MAX_PATH_LEN]; 15 MPI_Comm comm; 16 PetscMPIInt size; 17 PetscInt p; 18 PetscBool flg; 19 20 /*load matrix*/ 21 PetscFunctionBeginUser; 22 PetscCall(PetscInitialize(&argc, &args, NULL, help)); 23 comm = PETSC_COMM_WORLD; 24 PetscCallMPI(MPI_Comm_size(comm, &size)); 25 PetscCall(PetscOptionsGetString(NULL, NULL, "-fin", filein, sizeof(filein), &flg)); 26 if (flg) { 27 PetscViewer view; 28 PetscCall(PetscViewerBinaryOpen(comm, filein, FILE_MODE_READ, &view)); 29 PetscCall(MatCreate(comm, &A)); 30 PetscCall(MatLoad(A, view)); 31 PetscCall(PetscViewerDestroy(&view)); 32 } 33 34 /*partition matrix*/ 35 PetscCall(MatPartitioningCreate(comm, &part)); 36 PetscCall(MatPartitioningSetAdjacency(part, A)); 37 PetscCall(MatPartitioningSetFromOptions(part)); 38 PetscCall(MatPartitioningApply(part, &partis)); 39 PetscCall(MatGetOwnershipRanges(A, &ranges)); 40 PetscCall(MatGetSize(A, &min, NULL)); 41 for (p = 0; p < size; ++p) { 42 const PetscInt partsize = ranges[p + 1] - ranges[p]; 43 44 max = PetscMax(max, partsize); 45 min = PetscMin(min, partsize); 46 } 47 balance = ((PetscReal)max) / min; 48 PetscCall(PetscPrintf(comm, "ranges: ")); 49 for (p = 0; p <= size; ++p) { 50 if (p > 0) PetscCall(PetscPrintf(comm, ", ")); 51 PetscCall(PetscPrintf(comm, "%" PetscInt_FMT, ranges[p])); 52 } 53 PetscCall(PetscPrintf(comm, "\n")); 54 PetscCall(PetscPrintf(comm, "max:%.0lf min:%.0lf balance:%.11lf\n", (double)max, (double)min, (double)balance)); 55 PetscCall(PetscObjectViewFromOptions((PetscObject)partis, NULL, "-partition_view")); 56 PetscCall(MatPartitioningDestroy(&part)); 57 PetscCall(ISDestroy(&partis)); 58 PetscCall(MatDestroy(&A)); 59 PetscCall(PetscFinalize()); 60 return 0; 61 } 62