xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision e005ede52eafe2fed2813abb7a7eb3df04d5f886)
1 
2 #include "src/mat/impls/aij/mpi/mpiaij.h"
3 
4 EXTERN PetscErrorCode CreateColmap_MPIAIJ_Private(Mat);
5 EXTERN PetscErrorCode MatGetColumnIJ_SeqAIJ(Mat,PetscInt,PetscTruth,PetscInt*,PetscInt*[],PetscInt*[],PetscTruth*);
6 EXTERN PetscErrorCode MatRestoreColumnIJ_SeqAIJ(Mat,PetscInt,PetscTruth,PetscInt*,PetscInt*[],PetscInt*[],PetscTruth*);
7 
8 #undef __FUNCT__
9 #define __FUNCT__ "MatFDColoringCreate_MPIAIJ"
10 PetscErrorCode MatFDColoringCreate_MPIAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
11 {
12   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
13   PetscErrorCode ierr;
14   PetscMPIInt    size,*ncolsonproc,*disp,nn;
15   PetscInt       i,*is,n,nrows,j,k,m,*rows = 0,*A_ci,*A_cj,ncols,col;
16   PetscInt       nis = iscoloring->n,nctot,*cols,*B_ci,*B_cj;
17   PetscInt       *rowhit,M = mat->m,cstart = aij->cstart,cend = aij->cend,colb;
18   PetscInt       *columnsforrow,l;
19   IS             *isa;
20   PetscTruth     done,flg;
21 
22   PetscFunctionBegin;
23   if (!mat->assembled) {
24     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Matrix must be assembled first; MatAssemblyBegin/End();");
25   }
26 
27   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
28   c->M             = mat->M;  /* set the global rows and columns and local rows */
29   c->N             = mat->N;
30   c->m             = mat->m;
31   c->rstart        = aij->rstart;
32 
33   c->ncolors       = nis;
34   ierr             = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
35   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
36   ierr             = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
37   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->rows);CHKERRQ(ierr);
38   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->columnsforrow);CHKERRQ(ierr);
39   PetscLogObjectMemory(c,5*nis*sizeof(PetscInt));
40 
41   /* Allow access to data structures of local part of matrix */
42   if (!aij->colmap) {
43     ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
44   }
45   /*
46       Calls the _SeqAIJ() version of these routines to make sure it does not
47      get the reduced (by inodes) version of I and J
48   */
49   ierr = MatGetColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
50   ierr = MatGetColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
51 
52   ierr = MPI_Comm_size(mat->comm,&size);CHKERRQ(ierr);
53   ierr = PetscMalloc(2*size*sizeof(PetscInt*),&ncolsonproc);CHKERRQ(ierr);
54   disp = ncolsonproc + size;
55 
56   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&rowhit);CHKERRQ(ierr);
57   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&columnsforrow);CHKERRQ(ierr);
58 
59   /*
60      Temporary option to allow for debugging/testing
61   */
62   ierr = PetscOptionsHasName(PETSC_NULL,"-matfdcoloring_slow",&flg);CHKERRQ(ierr);
63 
64   for (i=0; i<nis; i++) {
65     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
66     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
67     c->ncolumns[i] = n;
68     c->ncolumns[i] = n;
69     if (n) {
70       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
71       PetscLogObjectMemory(c,n*sizeof(PetscInt));
72       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
73     } else {
74       c->columns[i]  = 0;
75     }
76 
77     /* Determine the total (parallel) number of columns of this color */
78     nn   = (PetscMPIInt)n;
79     ierr = MPI_Allgather(&nn,1,MPI_INT,ncolsonproc,1,MPI_INT,mat->comm);CHKERRQ(ierr);
80     nctot = 0; for (j=0; j<size; j++) {nctot += ncolsonproc[j];}
81     if (!nctot) {
82       PetscLogInfo((PetscObject)mat,"MatFDColoringCreate_MPIAIJ: Coloring of matrix has some unneeded colors with no corresponding rows\n");
83     }
84 
85     disp[0] = 0;
86     for (j=1; j<size; j++) {
87       disp[j] = disp[j-1] + ncolsonproc[j-1];
88     }
89 
90     /* Get complete list of columns for color on each processor */
91     ierr = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
92     ierr = MPI_Allgatherv(is,n,MPIU_INT,cols,ncolsonproc,disp,MPIU_INT,mat->comm);CHKERRQ(ierr);
93 
94     /*
95        Mark all rows affect by these columns
96     */
97     if (!flg) {/*-----------------------------------------------------------------------------*/
98       /* crude, fast version */
99       ierr = PetscMemzero(rowhit,M*sizeof(PetscInt));CHKERRQ(ierr);
100       /* loop over columns*/
101       for (j=0; j<nctot; j++) {
102         col  = cols[j];
103         if (col >= cstart && col < cend) {
104           /* column is in diagonal block of matrix */
105           rows = A_cj + A_ci[col-cstart];
106           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
107         } else {
108 #if defined (PETSC_USE_CTABLE)
109           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr)
110 	  colb --;
111 #else
112           colb = aij->colmap[col] - 1;
113 #endif
114           if (colb == -1) {
115             m = 0;
116           } else {
117             rows = B_cj + B_ci[colb];
118             m    = B_ci[colb+1] - B_ci[colb];
119           }
120         }
121         /* loop over columns marking them in rowhit */
122         for (k=0; k<m; k++) {
123           rowhit[*rows++] = col + 1;
124         }
125       }
126 
127       /* count the number of hits */
128       nrows = 0;
129       for (j=0; j<M; j++) {
130         if (rowhit[j]) nrows++;
131       }
132       c->nrows[i]         = nrows;
133       ierr                = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
134       ierr                = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
135       PetscLogObjectMemory(c,2*(nrows+1)*sizeof(PetscInt));
136       nrows = 0;
137       for (j=0; j<M; j++) {
138         if (rowhit[j]) {
139           c->rows[i][nrows]           = j;
140           c->columnsforrow[i][nrows] = rowhit[j] - 1;
141           nrows++;
142         }
143       }
144     } else {/*-------------------------------------------------------------------------------*/
145       /* slow version, using rowhit as a linked list */
146       PetscInt currentcol,fm,mfm;
147       rowhit[M] = M;
148       nrows     = 0;
149       /* loop over columns*/
150       for (j=0; j<nctot; j++) {
151         col  = cols[j];
152         if (col >= cstart && col < cend) {
153           /* column is in diagonal block of matrix */
154           rows = A_cj + A_ci[col-cstart];
155           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
156         } else {
157 #if defined (PETSC_USE_CTABLE)
158 	  ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
159           colb --;
160 #else
161           colb = aij->colmap[col] - 1;
162 #endif
163           if (colb == -1) {
164             m = 0;
165           } else {
166             rows = B_cj + B_ci[colb];
167             m    = B_ci[colb+1] - B_ci[colb];
168           }
169         }
170         /* loop over columns marking them in rowhit */
171         fm    = M; /* fm points to first entry in linked list */
172         for (k=0; k<m; k++) {
173           currentcol = *rows++;
174 	  /* is it already in the list? */
175           do {
176             mfm  = fm;
177             fm   = rowhit[fm];
178           } while (fm < currentcol);
179           /* not in list so add it */
180           if (fm != currentcol) {
181             nrows++;
182             columnsforrow[currentcol] = col;
183             /* next three lines insert new entry into linked list */
184             rowhit[mfm]               = currentcol;
185             rowhit[currentcol]        = fm;
186             fm                        = currentcol;
187             /* fm points to present position in list since we know the columns are sorted */
188           } else {
189             SETERRQ(PETSC_ERR_PLIB,"Invalid coloring of matrix detected");
190           }
191         }
192       }
193       c->nrows[i]         = nrows;
194       ierr = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
195       ierr = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
196       PetscLogObjectMemory(c,(nrows+1)*sizeof(PetscInt));
197       /* now store the linked list of rows into c->rows[i] */
198       nrows = 0;
199       fm    = rowhit[M];
200       do {
201         c->rows[i][nrows]            = fm;
202         c->columnsforrow[i][nrows++] = columnsforrow[fm];
203         fm                           = rowhit[fm];
204       } while (fm < M);
205     } /* ---------------------------------------------------------------------------------------*/
206     ierr = PetscFree(cols);CHKERRQ(ierr);
207   }
208 
209   /* Optimize by adding the vscale, and scaleforrow[][] fields */
210   /*
211        vscale will contain the "diagonal" on processor scalings followed by the off processor
212   */
213   ierr = VecCreateGhost(mat->comm,aij->A->m,PETSC_DETERMINE,aij->B->n,aij->garray,&c->vscale);CHKERRQ(ierr)
214   ierr = PetscMalloc(c->ncolors*sizeof(PetscInt*),&c->vscaleforrow);CHKERRQ(ierr);
215   for (k=0; k<c->ncolors; k++) {
216     ierr = PetscMalloc((c->nrows[k]+1)*sizeof(PetscInt),&c->vscaleforrow[k]);CHKERRQ(ierr);
217     for (l=0; l<c->nrows[k]; l++) {
218       col = c->columnsforrow[k][l];
219       if (col >= cstart && col < cend) {
220         /* column is in diagonal block of matrix */
221         colb = col - cstart;
222       } else {
223         /* column  is in "off-processor" part */
224 #if defined (PETSC_USE_CTABLE)
225         ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
226         colb --;
227 #else
228         colb = aij->colmap[col] - 1;
229 #endif
230         colb += cend - cstart;
231       }
232       c->vscaleforrow[k][l] = colb;
233     }
234   }
235   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
236 
237   ierr = PetscFree(rowhit);CHKERRQ(ierr);
238   ierr = PetscFree(columnsforrow);CHKERRQ(ierr);
239   ierr = PetscFree(ncolsonproc);CHKERRQ(ierr);
240   ierr = MatRestoreColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
241   ierr = MatRestoreColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
242   PetscFunctionReturn(0);
243 }
244 
245 
246 
247 
248 
249 
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