Actual source code: fdmpiaij.c

  1: /*$Id: fdmpiaij.c,v 1.41 2001/06/21 21:16:31 bsmith Exp $*/

 3:  #include src/mat/impls/aij/mpi/mpiaij.h
 4:  #include src/vec/vecimpl.h

  6: EXTERN int CreateColmap_MPIAIJ_Private(Mat);
  7: EXTERN int MatGetColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
  8: EXTERN int MatRestoreColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);

 10: int MatFDColoringCreate_MPIAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
 11: {
 12:   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
 13:   int        i,*is,n,nrows,j,k,m,*rows = 0,ierr,*A_ci,*A_cj,ncols,col;
 14:   int        nis = iscoloring->n,*ncolsonproc,size,nctot,*cols,*disp,*B_ci,*B_cj;
 15:   int        *rowhit,M = mat->m,cstart = aij->cstart,cend = aij->cend,colb;
 16:   int        *columnsforrow,l;
 17:   IS         *isa;
 18:   PetscTruth done,flg;

 21:   if (!mat->assembled) {
 22:     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Matrix must be assembled first; MatAssemblyBegin/End();");
 23:   }

 25:   ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);
 26:   c->M             = mat->M;  /* set the global rows and columns and local rows */
 27:   c->N             = mat->N;
 28:   c->m             = mat->m;
 29:   c->rstart        = aij->rstart;

 31:   c->ncolors       = nis;
 32:   ierr             = PetscMalloc(nis*sizeof(int),&c->ncolumns);
 33:   ierr             = PetscMalloc(nis*sizeof(int*),&c->columns);
 34:   ierr             = PetscMalloc(nis*sizeof(int),&c->nrows);
 35:   ierr             = PetscMalloc(nis*sizeof(int*),&c->rows);
 36:   ierr             = PetscMalloc(nis*sizeof(int*),&c->columnsforrow);
 37:   PetscLogObjectMemory(c,5*nis*sizeof(int));

 39:   /* Allow access to data structures of local part of matrix */
 40:   if (!aij->colmap) {
 41:     CreateColmap_MPIAIJ_Private(mat);
 42:   }
 43:   /*
 44:       Calls the _SeqAIJ() version of these routines to make sure it does not 
 45:      get the reduced (by inodes) version of I and J
 46:   */
 47:   MatGetColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);
 48:   MatGetColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);

 50:   MPI_Comm_size(mat->comm,&size);
 51:   PetscMalloc(2*size*sizeof(int*),&ncolsonproc);
 52:   disp = ncolsonproc + size;

 54:   PetscMalloc((M+1)*sizeof(int),&rowhit);
 55:   PetscMalloc((M+1)*sizeof(int),&columnsforrow);

 57:   /*
 58:      Temporary option to allow for debugging/testing
 59:   */
 60:   PetscOptionsHasName(PETSC_NULL,"-matfdcoloring_slow",&flg);

 62:   for (i=0; i<nis; i++) {
 63:     ISGetLocalSize(isa[i],&n);
 64:     ISGetIndices(isa[i],&is);
 65:     c->ncolumns[i] = n;
 66:     c->ncolumns[i] = n;
 67:     if (n) {
 68:       PetscMalloc(n*sizeof(int),&c->columns[i]);
 69:       PetscLogObjectMemory(c,n*sizeof(int));
 70:       PetscMemcpy(c->columns[i],is,n*sizeof(int));
 71:     } else {
 72:       c->columns[i]  = 0;
 73:     }

 75:     /* Determine the total (parallel) number of columns of this color */
 76:     MPI_Allgather(&n,1,MPI_INT,ncolsonproc,1,MPI_INT,mat->comm);
 77:     nctot = 0; for (j=0; j<size; j++) {nctot += ncolsonproc[j];}
 78:     if (!nctot) {
 79:       PetscLogInfo((PetscObject)mat,"MatFDColoringCreate_MPIAIJ: Coloring of matrix has some unneeded colors with no corresponding rowsn");
 80:     }

 82:     disp[0] = 0;
 83:     for (j=1; j<size; j++) {
 84:       disp[j] = disp[j-1] + ncolsonproc[j-1];
 85:     }
 86: 
 87:     /* Get complete list of columns for color on each processor */
 88:     PetscMalloc((nctot+1)*sizeof(int),&cols);
 89:     MPI_Allgatherv(is,n,MPI_INT,cols,ncolsonproc,disp,MPI_INT,mat->comm);

 91:     /*
 92:        Mark all rows affect by these columns
 93:     */
 94:     if (!flg) {/*-----------------------------------------------------------------------------*/
 95:       /* crude, fast version */
 96:       PetscMemzero(rowhit,M*sizeof(int));
 97:       /* loop over columns*/
 98:       for (j=0; j<nctot; j++) {
 99:         col  = cols[j];
100:         if (col >= cstart && col < cend) {
101:           /* column is in diagonal block of matrix */
102:           rows = A_cj + A_ci[col-cstart];
103:           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
104:         } else {
105: #if defined (PETSC_USE_CTABLE)
106:           PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr)
107:           colb --;
108: #else
109:           colb = aij->colmap[col] - 1;
110: #endif
111:           if (colb == -1) {
112:             m = 0;
113:           } else {
114:             rows = B_cj + B_ci[colb];
115:             m    = B_ci[colb+1] - B_ci[colb];
116:           }
117:         }
118:         /* loop over columns marking them in rowhit */
119:         for (k=0; k<m; k++) {
120:           rowhit[*rows++] = col + 1;
121:         }
122:       }

124:       /* count the number of hits */
125:       nrows = 0;
126:       for (j=0; j<M; j++) {
127:         if (rowhit[j]) nrows++;
128:       }
129:       c->nrows[i]         = nrows;
130:       ierr                = PetscMalloc((nrows+1)*sizeof(int),&c->rows[i]);
131:       ierr                = PetscMalloc((nrows+1)*sizeof(int),&c->columnsforrow[i]);
132:       PetscLogObjectMemory(c,2*(nrows+1)*sizeof(int));
133:       nrows = 0;
134:       for (j=0; j<M; j++) {
135:         if (rowhit[j]) {
136:           c->rows[i][nrows]           = j;
137:           c->columnsforrow[i][nrows] = rowhit[j] - 1;
138:           nrows++;
139:         }
140:       }
141:     } else {/*-------------------------------------------------------------------------------*/
142:       /* slow version, using rowhit as a linked list */
143:       int currentcol,fm,mfm;
144:       rowhit[M] = M;
145:       nrows     = 0;
146:       /* loop over columns*/
147:       for (j=0; j<nctot; j++) {
148:         col  = cols[j];
149:         if (col >= cstart && col < cend) {
150:           /* column is in diagonal block of matrix */
151:           rows = A_cj + A_ci[col-cstart];
152:           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
153:         } else {
154: #if defined (PETSC_USE_CTABLE)
155:           PetscTableFind(aij->colmap,col+1,&colb);
156:           colb --;
157: #else
158:           colb = aij->colmap[col] - 1;
159: #endif
160:           if (colb == -1) {
161:             m = 0;
162:           } else {
163:             rows = B_cj + B_ci[colb];
164:             m    = B_ci[colb+1] - B_ci[colb];
165:           }
166:         }
167:         /* loop over columns marking them in rowhit */
168:         fm    = M; /* fm points to first entry in linked list */
169:         for (k=0; k<m; k++) {
170:           currentcol = *rows++;
171:           /* is it already in the list? */
172:           do {
173:             mfm  = fm;
174:             fm   = rowhit[fm];
175:           } while (fm < currentcol);
176:           /* not in list so add it */
177:           if (fm != currentcol) {
178:             nrows++;
179:             columnsforrow[currentcol] = col;
180:             /* next three lines insert new entry into linked list */
181:             rowhit[mfm]               = currentcol;
182:             rowhit[currentcol]        = fm;
183:             fm                        = currentcol;
184:             /* fm points to present position in list since we know the columns are sorted */
185:           } else {
186:             SETERRQ(PETSC_ERR_PLIB,"Invalid coloring of matrix detected");
187:           }
188:         }
189:       }
190:       c->nrows[i]         = nrows;
191:       PetscMalloc((nrows+1)*sizeof(int),&c->rows[i]);
192:       PetscMalloc((nrows+1)*sizeof(int),&c->columnsforrow[i]);
193:       PetscLogObjectMemory(c,(nrows+1)*sizeof(int));
194:       /* now store the linked list of rows into c->rows[i] */
195:       nrows = 0;
196:       fm    = rowhit[M];
197:       do {
198:         c->rows[i][nrows]            = fm;
199:         c->columnsforrow[i][nrows++] = columnsforrow[fm];
200:         fm                           = rowhit[fm];
201:       } while (fm < M);
202:     } /* ---------------------------------------------------------------------------------------*/
203:     PetscFree(cols);
204:   }

206:   /* Optimize by adding the vscale, and scaleforrow[][] fields */
207:   /*
208:        vscale will contain the "diagonal" on processor scalings followed by the off processor
209:   */
210:   VecCreateGhost(mat->comm,aij->A->m,PETSC_DETERMINE,aij->B->n,aij->garray,&c->vscale);CHKERRQ(ierr)
211:   PetscMalloc(c->ncolors*sizeof(int*),&c->vscaleforrow);
212:   for (k=0; k<c->ncolors; k++) {
213:     PetscMalloc((c->nrows[k]+1)*sizeof(int),&c->vscaleforrow[k]);
214:     for (l=0; l<c->nrows[k]; l++) {
215:       col = c->columnsforrow[k][l];
216:       if (col >= cstart && col < cend) {
217:         /* column is in diagonal block of matrix */
218:         colb = col - cstart;
219:       } else {
220:         /* column  is in "off-processor" part */
221: #if defined (PETSC_USE_CTABLE)
222:         PetscTableFind(aij->colmap,col+1,&colb);
223:         colb --;
224: #else
225:         colb = aij->colmap[col] - 1;
226: #endif
227:         colb += cend - cstart;
228:       }
229:       c->vscaleforrow[k][l] = colb;
230:     }
231:   }
232:   ISColoringRestoreIS(iscoloring,&isa);

234:   PetscFree(rowhit);
235:   PetscFree(columnsforrow);
236:   PetscFree(ncolsonproc);
237:   MatRestoreColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);
238:   MatRestoreColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);
239:   return(0);
240: }