xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision 09f3b4e5628a00a1eaf17d80982cfbcc515cc9c1)
1 #define PETSCMAT_DLL
2 
3 #include "src/mat/impls/aij/mpi/mpiaij.h"
4 
5 EXTERN PetscErrorCode CreateColmap_MPIAIJ_Private(Mat);
6 EXTERN PetscErrorCode MatGetColumnIJ_SeqAIJ(Mat,PetscInt,PetscTruth,PetscInt*,PetscInt*[],PetscInt*[],PetscTruth*);
7 EXTERN PetscErrorCode MatRestoreColumnIJ_SeqAIJ(Mat,PetscInt,PetscTruth,PetscInt*,PetscInt*[],PetscInt*[],PetscTruth*);
8 
9 #undef __FUNCT__
10 #define __FUNCT__ "MatFDColoringCreate_MPIAIJ"
11 PetscErrorCode MatFDColoringCreate_MPIAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
12 {
13   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
14   PetscErrorCode ierr;
15   PetscMPIInt    size,*ncolsonproc,*disp,nn;
16   PetscInt       i,*is,n,nrows,j,k,m,*rows = 0,*A_ci,*A_cj,ncols,col;
17   PetscInt       nis = iscoloring->n,nctot,*cols,*B_ci,*B_cj;
18   PetscInt       *rowhit,M = mat->m,cstart = aij->cstart,cend = aij->cend,colb;
19   PetscInt       *columnsforrow,l;
20   IS             *isa;
21   PetscTruth     done,flg;
22 
23   PetscFunctionBegin;
24   if (!mat->assembled) {
25     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Matrix must be assembled first; MatAssemblyBegin/End();");
26   }
27 
28   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
29   c->M             = mat->M;  /* set the global rows and columns and local rows */
30   c->N             = mat->N;
31   c->m             = mat->m;
32   c->rstart        = aij->rstart;
33 
34   c->ncolors       = nis;
35   ierr             = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
36   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
37   ierr             = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
38   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->rows);CHKERRQ(ierr);
39   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->columnsforrow);CHKERRQ(ierr);
40   ierr = PetscLogObjectMemory(c,5*nis*sizeof(PetscInt));CHKERRQ(ierr);
41 
42   /* Allow access to data structures of local part of matrix */
43   if (!aij->colmap) {
44     ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
45   }
46   /*
47       Calls the _SeqAIJ() version of these routines to make sure it does not
48      get the reduced (by inodes) version of I and J
49   */
50   ierr = MatGetColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
51   ierr = MatGetColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
52 
53   ierr = MPI_Comm_size(mat->comm,&size);CHKERRQ(ierr);
54   ierr = PetscMalloc(2*size*sizeof(PetscInt*),&ncolsonproc);CHKERRQ(ierr);
55   disp = ncolsonproc + size;
56 
57   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&rowhit);CHKERRQ(ierr);
58   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&columnsforrow);CHKERRQ(ierr);
59 
60   /*
61      Temporary option to allow for debugging/testing
62   */
63   ierr = PetscOptionsHasName(PETSC_NULL,"-matfdcoloring_slow",&flg);CHKERRQ(ierr);
64 
65   for (i=0; i<nis; i++) {
66     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
67     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
68     c->ncolumns[i] = n;
69     c->ncolumns[i] = n;
70     if (n) {
71       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
72       ierr = PetscLogObjectMemory(c,n*sizeof(PetscInt));CHKERRQ(ierr);
73       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
74     } else {
75       c->columns[i]  = 0;
76     }
77 
78     /* Determine the total (parallel) number of columns of this color */
79     nn   = (PetscMPIInt)n;
80     ierr = MPI_Allgather(&nn,1,MPI_INT,ncolsonproc,1,MPI_INT,mat->comm);CHKERRQ(ierr);
81     nctot = 0; for (j=0; j<size; j++) {nctot += ncolsonproc[j];}
82     if (!nctot) {
83       ierr = PetscVerboseInfo(((PetscObject)mat,"MatFDColoringCreate_MPIAIJ: Coloring of matrix has some unneeded colors with no corresponding rows\n"));CHKERRQ(ierr);
84     }
85 
86     disp[0] = 0;
87     for (j=1; j<size; j++) {
88       disp[j] = disp[j-1] + ncolsonproc[j-1];
89     }
90 
91     /* Get complete list of columns for color on each processor */
92     ierr = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
93     ierr = MPI_Allgatherv(is,n,MPIU_INT,cols,ncolsonproc,disp,MPIU_INT,mat->comm);CHKERRQ(ierr);
94 
95     /*
96        Mark all rows affect by these columns
97     */
98     if (!flg) {/*-----------------------------------------------------------------------------*/
99       /* crude, fast version */
100       ierr = PetscMemzero(rowhit,M*sizeof(PetscInt));CHKERRQ(ierr);
101       /* loop over columns*/
102       for (j=0; j<nctot; j++) {
103         col  = cols[j];
104         if (col >= cstart && col < cend) {
105           /* column is in diagonal block of matrix */
106           rows = A_cj + A_ci[col-cstart];
107           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
108         } else {
109 #if defined (PETSC_USE_CTABLE)
110           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr)
111 	  colb --;
112 #else
113           colb = aij->colmap[col] - 1;
114 #endif
115           if (colb == -1) {
116             m = 0;
117           } else {
118             rows = B_cj + B_ci[colb];
119             m    = B_ci[colb+1] - B_ci[colb];
120           }
121         }
122         /* loop over columns marking them in rowhit */
123         for (k=0; k<m; k++) {
124           rowhit[*rows++] = col + 1;
125         }
126       }
127 
128       /* count the number of hits */
129       nrows = 0;
130       for (j=0; j<M; j++) {
131         if (rowhit[j]) nrows++;
132       }
133       c->nrows[i]         = nrows;
134       ierr                = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
135       ierr                = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
136       ierr = PetscLogObjectMemory(c,2*(nrows+1)*sizeof(PetscInt));CHKERRQ(ierr);
137       nrows = 0;
138       for (j=0; j<M; j++) {
139         if (rowhit[j]) {
140           c->rows[i][nrows]           = j;
141           c->columnsforrow[i][nrows] = rowhit[j] - 1;
142           nrows++;
143         }
144       }
145     } else {/*-------------------------------------------------------------------------------*/
146       /* slow version, using rowhit as a linked list */
147       PetscInt currentcol,fm,mfm;
148       rowhit[M] = M;
149       nrows     = 0;
150       /* loop over columns*/
151       for (j=0; j<nctot; j++) {
152         col  = cols[j];
153         if (col >= cstart && col < cend) {
154           /* column is in diagonal block of matrix */
155           rows = A_cj + A_ci[col-cstart];
156           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
157         } else {
158 #if defined (PETSC_USE_CTABLE)
159 	  ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
160           colb --;
161 #else
162           colb = aij->colmap[col] - 1;
163 #endif
164           if (colb == -1) {
165             m = 0;
166           } else {
167             rows = B_cj + B_ci[colb];
168             m    = B_ci[colb+1] - B_ci[colb];
169           }
170         }
171         /* loop over columns marking them in rowhit */
172         fm    = M; /* fm points to first entry in linked list */
173         for (k=0; k<m; k++) {
174           currentcol = *rows++;
175 	  /* is it already in the list? */
176           do {
177             mfm  = fm;
178             fm   = rowhit[fm];
179           } while (fm < currentcol);
180           /* not in list so add it */
181           if (fm != currentcol) {
182             nrows++;
183             columnsforrow[currentcol] = col;
184             /* next three lines insert new entry into linked list */
185             rowhit[mfm]               = currentcol;
186             rowhit[currentcol]        = fm;
187             fm                        = currentcol;
188             /* fm points to present position in list since we know the columns are sorted */
189           } else {
190             SETERRQ(PETSC_ERR_PLIB,"Invalid coloring of matrix detected");
191           }
192         }
193       }
194       c->nrows[i]         = nrows;
195       ierr = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
196       ierr = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
197       ierr = PetscLogObjectMemory(c,(nrows+1)*sizeof(PetscInt));CHKERRQ(ierr);
198       /* now store the linked list of rows into c->rows[i] */
199       nrows = 0;
200       fm    = rowhit[M];
201       do {
202         c->rows[i][nrows]            = fm;
203         c->columnsforrow[i][nrows++] = columnsforrow[fm];
204         fm                           = rowhit[fm];
205       } while (fm < M);
206     } /* ---------------------------------------------------------------------------------------*/
207     ierr = PetscFree(cols);CHKERRQ(ierr);
208   }
209 
210   /* Optimize by adding the vscale, and scaleforrow[][] fields */
211   /*
212        vscale will contain the "diagonal" on processor scalings followed by the off processor
213   */
214   ierr = VecCreateGhost(mat->comm,aij->A->m,PETSC_DETERMINE,aij->B->n,aij->garray,&c->vscale);CHKERRQ(ierr)
215   ierr = PetscMalloc(c->ncolors*sizeof(PetscInt*),&c->vscaleforrow);CHKERRQ(ierr);
216   for (k=0; k<c->ncolors; k++) {
217     ierr = PetscMalloc((c->nrows[k]+1)*sizeof(PetscInt),&c->vscaleforrow[k]);CHKERRQ(ierr);
218     for (l=0; l<c->nrows[k]; l++) {
219       col = c->columnsforrow[k][l];
220       if (col >= cstart && col < cend) {
221         /* column is in diagonal block of matrix */
222         colb = col - cstart;
223       } else {
224         /* column  is in "off-processor" part */
225 #if defined (PETSC_USE_CTABLE)
226         ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
227         colb --;
228 #else
229         colb = aij->colmap[col] - 1;
230 #endif
231         colb += cend - cstart;
232       }
233       c->vscaleforrow[k][l] = colb;
234     }
235   }
236   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
237 
238   ierr = PetscFree(rowhit);CHKERRQ(ierr);
239   ierr = PetscFree(columnsforrow);CHKERRQ(ierr);
240   ierr = PetscFree(ncolsonproc);CHKERRQ(ierr);
241   ierr = MatRestoreColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
242   ierr = MatRestoreColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
243   PetscFunctionReturn(0);
244 }
245 
246 
247 
248 
249 
250 
251