Actual source code: ex33.c

  1: static char help[] = "Test memory scalability of MatMatMult() for AIJ and DENSE matrices. \n\
  2: Modified from the code contributed by Ian Lin <iancclin@umich.edu> \n\n";

  4: /*
  5: Example:
  6:   mpiexec -n <np> ./ex33 -mem_view -matmatmult_Bbn <Bbn>
  7: */

  9: #include <petsc.h>

 11: PetscErrorCode Print_memory(PetscLogDouble mem)
 12: {
 13:   double         max_mem,min_mem;

 16:   MPI_Reduce(&mem, &max_mem, 1, MPI_DOUBLE, MPI_MAX, 0, MPI_COMM_WORLD);
 17:   MPI_Reduce(&mem, &min_mem, 1, MPI_DOUBLE, MPI_MIN, 0, MPI_COMM_WORLD);
 18:   max_mem = max_mem / 1024.0 / 1024.0;
 19:   min_mem = min_mem / 1024.0 / 1024.0;
 20:   PetscPrintf(MPI_COMM_WORLD, " max and min memory across all processors %.4f Mb, %.4f Mb.\n", (double)max_mem,(double)min_mem);
 21:   return 0;
 22: }

 24: /*
 25:    Illustrate how to use MPI derived data types.
 26:    It would save memory significantly. See MatMPIDenseScatter()
 27: */
 28: PetscErrorCode TestMPIDerivedDataType()
 29: {
 30:   MPI_Datatype      type1, type2,rtype1,rtype2;
 31:   PetscInt          i,j;
 32:   PetscScalar       buffer[24]; /* An array of 4 rows, 6 cols */
 33:   MPI_Status        status;
 34:   PetscMPIInt       rank,size,disp[2];

 37:   MPI_Comm_size(MPI_COMM_WORLD, &size);
 39:   MPI_Comm_rank(MPI_COMM_WORLD, &rank);

 41:   if (rank == 0) {
 42:     /* proc[0] sends 2 rows to proc[1] */
 43:     for (i=0; i<24; i++) buffer[i] = (PetscScalar)i;

 45:     disp[0] = 0;  disp[1] = 2;
 46:     MPI_Type_create_indexed_block(2, 1, (const PetscMPIInt *)disp, MPIU_SCALAR, &type1);
 47:     /* one column has 4 entries */
 48:     MPI_Type_create_resized(type1,0,4*sizeof(PetscScalar),&type2);
 49:     MPI_Type_commit(&type2);
 50:     MPI_Send(buffer, 6, type2, 1, 123, MPI_COMM_WORLD);

 52:   } else if (rank == 1) {
 53:     /* proc[1] receives 2 rows from proc[0], and put them into contiguous rows, starting at the row 1 (disp[0]) */
 54:     PetscInt blen = 2;
 55:     for (i=0; i<24; i++) buffer[i] = 0.0;

 57:     disp[0] = 1;
 58:     MPI_Type_create_indexed_block(1, blen, (const PetscMPIInt *)disp, MPIU_SCALAR, &rtype1);
 59:     MPI_Type_create_resized(rtype1, 0, 4*sizeof(PetscScalar), &rtype2);

 61:     MPI_Type_commit(&rtype2);
 62:     MPI_Recv(buffer, 6, rtype2, 0, 123, MPI_COMM_WORLD, &status);
 63:     for (i=0; i<4; i++) {
 64:       for (j=0; j<6; j++) {
 65:         PetscPrintf(MPI_COMM_SELF,"  %g", (double)PetscRealPart(buffer[i+j*4]));
 66:       }
 67:       PetscPrintf(MPI_COMM_SELF,"\n");
 68:     }
 69:   }

 71:   if (rank == 0) {
 72:     MPI_Type_free(&type1);
 73:     MPI_Type_free(&type2);
 74:   } else if (rank == 1) {
 75:     MPI_Type_free(&rtype1);
 76:     MPI_Type_free(&rtype2);
 77:   }
 78:   MPI_Barrier(MPI_COMM_WORLD);
 79:   return 0;
 80: }

 82: int main(int argc, char **args)
 83: {
 84:   PetscInt          mA = 2700,nX = 80,nz = 40;
 85:   /* PetscInt        mA=6,nX=5,nz=2; //small test */
 86:   PetscLogDouble    mem;
 87:   Mat               A,X,Y;
 88:   PetscBool         flg = PETSC_FALSE;

 90:   PetscInitialize(&argc,&args,(char*)0,help);
 91:   PetscOptionsGetBool(NULL,NULL,"-test_mpiderivedtype",&flg,NULL);
 92:   if (flg) {
 93:     TestMPIDerivedDataType();
 94:     PetscFinalize();
 95:     return 0;
 96:   }

 98:   PetscOptionsGetBool(NULL,NULL,"-mem_view",&flg,NULL);
 99:   PetscMemoryGetCurrentUsage(&mem);
100:   if (flg) {
101:     PetscPrintf(MPI_COMM_WORLD, "Before start,");
102:     Print_memory(mem);
103:   }

105:   MatCreateAIJ(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,mA,mA,nz,PETSC_NULL,nz,PETSC_NULL,&A);
106:   MatSetRandom(A,PETSC_NULL);
107:   PetscMemoryGetCurrentUsage(&mem);
108:   if (flg) {
109:     PetscPrintf(MPI_COMM_WORLD, "After creating A,");
110:     Print_memory(mem);
111:   }

113:   MatCreateDense(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,mA,nX,PETSC_NULL,&X);
114:   MatSetRandom(X,PETSC_NULL);
115:   PetscMemoryGetCurrentUsage(&mem);
116:   if (flg) {
117:     PetscPrintf(MPI_COMM_WORLD, "After creating X,");
118:     Print_memory(mem);
119:   }

121:   MatMatMult(A,X,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&Y);
122:   PetscMemoryGetCurrentUsage(&mem);
123:   if (flg) {
124:     PetscPrintf(MPI_COMM_WORLD, "After MatMatMult,");
125:     Print_memory(mem);
126:   }

128:   /* Test reuse */
129:   MatMatMult(A,X,MAT_REUSE_MATRIX,PETSC_DEFAULT,&Y);
130:   PetscMemoryGetCurrentUsage(&mem);
131:   if (flg) {
132:     PetscPrintf(MPI_COMM_WORLD, "After reuse MatMatMult,");
133:     Print_memory(mem);
134:   }

136:   /* Check accuracy */
137:   MatMatMultEqual(A,X,Y,10,&flg);

140:   MatDestroy(&A);
141:   MatDestroy(&X);
142:   MatDestroy(&Y);

144:   PetscFinalize();
145:   return 0;
146: }

148: /*TEST

150:    test:
151:       suffix: 1
152:       nsize: 4
153:       output_file: output/ex33.out

155:    test:
156:       suffix: 2
157:       nsize: 8
158:       output_file: output/ex33.out

160:    test:
161:       suffix: 3
162:       nsize: 2
163:       args: -test_mpiderivedtype
164:       output_file: output/ex33_3.out

166: TEST*/