1 static char help[] = "Compare parallel partitioning strategies using matrix graphs\n\n";
2
3 #include <petscmat.h>
4
main(int argc,char ** args)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