xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision 8cc058d9cd56c1ccb3be12a47760ddfc446aaffc)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>
3 
4 extern PetscErrorCode MatCreateColmap_MPIAIJ_Private(Mat);
5 
6 #undef __FUNCT__
7 #define __FUNCT__ "MatFDColoringCreate_MPIAIJ"
8 PetscErrorCode MatFDColoringCreate_MPIAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
9 {
10   Mat_MPIAIJ             *aij = (Mat_MPIAIJ*)mat->data;
11   PetscErrorCode         ierr;
12   PetscMPIInt            size,*ncolsonproc,*disp,nn;
13   PetscInt               i,n,nrows,j,k,m,ncols,col;
14   const PetscInt         *is,*A_ci,*A_cj,*B_ci,*B_cj,*rows = 0,*ltog;
15   PetscInt               nis = iscoloring->n,nctot,*cols;
16   PetscInt               *rowhit,M,cstart,cend,colb;
17   PetscInt               *columnsforrow,l;
18   IS                     *isa;
19   PetscBool              done,flg;
20   ISLocalToGlobalMapping map   = mat->cmap->mapping;
21   PetscInt               ctype=c->ctype;
22 
23   PetscFunctionBegin;
24   if (!mat->assembled) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Matrix must be assembled first; MatAssemblyBegin/End();");
25   if (ctype == IS_COLORING_GHOSTED && !map) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_INCOMP,"When using ghosted differencing matrix must have local to global mapping provided with MatSetLocalToGlobalMapping");
26 
27   if (map) {ierr = ISLocalToGlobalMappingGetIndices(map,&ltog);CHKERRQ(ierr);}
28   else     ltog = NULL;
29   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
30 
31   M         = mat->rmap->n;
32   cstart    = mat->cmap->rstart;
33   cend      = mat->cmap->rend;
34   c->M      = mat->rmap->N;         /* set the global rows and columns and local rows */
35   c->N      = mat->cmap->N;
36   c->m      = mat->rmap->n;
37   c->rstart = mat->rmap->rstart;
38 
39   c->ncolors = nis;
40   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
41   ierr       = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
42   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
43   ierr       = PetscMalloc(nis*sizeof(PetscInt*),&c->rows);CHKERRQ(ierr);
44   ierr       = PetscMalloc(nis*sizeof(PetscInt*),&c->columnsforrow);CHKERRQ(ierr);
45   ierr       = PetscLogObjectMemory(c,5*nis*sizeof(PetscInt));CHKERRQ(ierr);
46 
47   /* Allow access to data structures of local part of matrix */
48   if (!aij->colmap) {
49     ierr = MatCreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
50   }
51   ierr = MatGetColumnIJ(aij->A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
52   ierr = MatGetColumnIJ(aij->B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
53 
54   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&rowhit);CHKERRQ(ierr);
55   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&columnsforrow);CHKERRQ(ierr);
56 
57   for (i=0; i<nis; i++) {
58     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
59     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
60 
61     c->ncolumns[i] = n;
62     if (n) {
63       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
64       ierr = PetscLogObjectMemory(c,n*sizeof(PetscInt));CHKERRQ(ierr);
65       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
66     } else {
67       c->columns[i] = 0;
68     }
69 
70     if (ctype == IS_COLORING_GLOBAL) {
71       /* Determine the total (parallel) number of columns of this color */
72       ierr = MPI_Comm_size(PetscObjectComm((PetscObject)mat),&size);CHKERRQ(ierr);
73       ierr = PetscMalloc2(size,PetscMPIInt,&ncolsonproc,size,PetscMPIInt,&disp);CHKERRQ(ierr);
74 
75       ierr  = PetscMPIIntCast(n,&nn);CHKERRQ(ierr);
76       ierr  = MPI_Allgather(&nn,1,MPI_INT,ncolsonproc,1,MPI_INT,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
77       nctot = 0; for (j=0; j<size; j++) nctot += ncolsonproc[j];
78       if (!nctot) {
79         ierr = PetscInfo(mat,"Coloring of matrix has some unneeded colors with no corresponding rows\n");CHKERRQ(ierr);
80       }
81 
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       ierr = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
89       ierr = MPI_Allgatherv((void*)is,n,MPIU_INT,cols,ncolsonproc,disp,MPIU_INT,PetscObjectComm((PetscObject)mat));CHKERRQ(ierr);
90       ierr = PetscFree2(ncolsonproc,disp);CHKERRQ(ierr);
91     } else if (ctype == IS_COLORING_GHOSTED) {
92       /* Determine local number of columns of this color on this process, including ghost points */
93       nctot = n;
94       ierr  = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
95       ierr  = PetscMemcpy(cols,is,n*sizeof(PetscInt));CHKERRQ(ierr);
96     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not provided for this MatFDColoring type");
97 
98     /*
99        Mark all rows affect by these columns
100     */
101     /* Temporary option to allow for debugging/testing */
102     flg  = PETSC_FALSE;
103     ierr = PetscOptionsGetBool(NULL,"-matfdcoloring_slow",&flg,NULL);CHKERRQ(ierr);
104     if (!flg) { /*-----------------------------------------------------------------------------*/
105       /* crude, fast version */
106       ierr = PetscMemzero(rowhit,M*sizeof(PetscInt));CHKERRQ(ierr);
107       /* loop over columns*/
108       for (j=0; j<nctot; j++) {
109         if (ctype == IS_COLORING_GHOSTED) {
110           col = ltog[cols[j]];
111         } else {
112           col = cols[j];
113         }
114         if (col >= cstart && col < cend) {
115           /* column is in diagonal block of matrix */
116           rows = A_cj + A_ci[col-cstart];
117           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
118         } else {
119 #if defined(PETSC_USE_CTABLE)
120           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
121           colb--;
122 #else
123           colb = aij->colmap[col] - 1;
124 #endif
125           if (colb == -1) {
126             m = 0;
127           } else {
128             rows = B_cj + B_ci[colb];
129             m    = B_ci[colb+1] - B_ci[colb];
130           }
131         }
132         /* loop over columns marking them in rowhit */
133         for (k=0; k<m; k++) {
134           rowhit[*rows++] = col + 1;
135         }
136       }
137 
138       /* count the number of hits */
139       nrows = 0;
140       for (j=0; j<M; j++) {
141         if (rowhit[j]) nrows++;
142       }
143       c->nrows[i] = nrows;
144       ierr        = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
145       ierr        = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
146       ierr        = PetscLogObjectMemory(c,2*(nrows+1)*sizeof(PetscInt));CHKERRQ(ierr);
147       nrows       = 0;
148       for (j=0; j<M; j++) {
149         if (rowhit[j]) {
150           c->rows[i][nrows]          = j;
151           c->columnsforrow[i][nrows] = rowhit[j] - 1;
152           nrows++;
153         }
154       }
155     } else { /*-------------------------------------------------------------------------------*/
156       /* slow version, using rowhit as a linked list */
157       PetscInt currentcol,fm,mfm;
158       rowhit[M] = M;
159       nrows     = 0;
160       /* loop over columns*/
161       for (j=0; j<nctot; j++) {
162         if (ctype == IS_COLORING_GHOSTED) {
163           col = ltog[cols[j]];
164         } else {
165           col = cols[j];
166         }
167         if (col >= cstart && col < cend) {
168           /* column is in diagonal block of matrix */
169           rows = A_cj + A_ci[col-cstart];
170           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
171         } else {
172 #if defined(PETSC_USE_CTABLE)
173           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
174           colb--;
175 #else
176           colb = aij->colmap[col] - 1;
177 #endif
178           if (colb == -1) {
179             m = 0;
180           } else {
181             rows = B_cj + B_ci[colb];
182             m    = B_ci[colb+1] - B_ci[colb];
183           }
184         }
185 
186         /* loop over columns marking them in rowhit */
187         fm = M;    /* fm points to first entry in linked list */
188         for (k=0; k<m; k++) {
189           currentcol = *rows++;
190           /* is it already in the list? */
191           do {
192             mfm = fm;
193             fm  = rowhit[fm];
194           } while (fm < currentcol);
195           /* not in list so add it */
196           if (fm != currentcol) {
197             nrows++;
198             columnsforrow[currentcol] = col;
199             /* next three lines insert new entry into linked list */
200             rowhit[mfm]        = currentcol;
201             rowhit[currentcol] = fm;
202             fm                 = currentcol;
203             /* fm points to present position in list since we know the columns are sorted */
204           } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Invalid coloring of matrix detected");
205         }
206       }
207       c->nrows[i] = nrows;
208 
209       ierr = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
210       ierr = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
211       ierr = PetscLogObjectMemory(c,(nrows+1)*sizeof(PetscInt));CHKERRQ(ierr);
212       /* now store the linked list of rows into c->rows[i] */
213       nrows = 0;
214       fm    = rowhit[M];
215       do {
216         c->rows[i][nrows]            = fm;
217         c->columnsforrow[i][nrows++] = columnsforrow[fm];
218         fm                           = rowhit[fm];
219       } while (fm < M);
220     } /* ---------------------------------------------------------------------------------------*/
221     ierr = PetscFree(cols);CHKERRQ(ierr);
222   }
223 
224   /* Optimize by adding the vscale, and scaleforrow[][] fields */
225   /*
226        vscale will contain the "diagonal" on processor scalings followed by the off processor
227   */
228   if (ctype == IS_COLORING_GLOBAL) {
229     ierr = VecCreateGhost(PetscObjectComm((PetscObject)mat),aij->A->rmap->n,PETSC_DETERMINE,aij->B->cmap->n,aij->garray,&c->vscale);CHKERRQ(ierr);
230     ierr = PetscMalloc(c->ncolors*sizeof(PetscInt*),&c->vscaleforrow);CHKERRQ(ierr);
231     for (k=0; k<c->ncolors; k++) {
232       ierr = PetscMalloc((c->nrows[k]+1)*sizeof(PetscInt),&c->vscaleforrow[k]);CHKERRQ(ierr);
233       for (l=0; l<c->nrows[k]; l++) {
234         col = c->columnsforrow[k][l];
235         if (col >= cstart && col < cend) {
236           /* column is in diagonal block of matrix */
237           colb = col - cstart;
238         } else {
239           /* column  is in "off-processor" part */
240 #if defined(PETSC_USE_CTABLE)
241           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
242           colb--;
243 #else
244           colb = aij->colmap[col] - 1;
245 #endif
246           colb += cend - cstart;
247         }
248         c->vscaleforrow[k][l] = colb;
249       }
250     }
251   } else if (ctype == IS_COLORING_GHOSTED) {
252     /* Get gtol mapping */
253     PetscInt N = mat->cmap->N,nlocal,*gtol;
254     ierr = PetscMalloc((N+1)*sizeof(PetscInt),&gtol);CHKERRQ(ierr);
255     for (i=0; i<N; i++) gtol[i] = -1;
256     ierr = ISLocalToGlobalMappingGetSize(map,&nlocal);CHKERRQ(ierr);
257     for (i=0; i<nlocal; i++) gtol[ltog[i]] = i;
258 
259     c->vscale = 0; /* will be created in MatFDColoringApply() */
260     ierr      = PetscMalloc(c->ncolors*sizeof(PetscInt*),&c->vscaleforrow);CHKERRQ(ierr);
261     for (k=0; k<c->ncolors; k++) {
262       ierr = PetscMalloc((c->nrows[k]+1)*sizeof(PetscInt),&c->vscaleforrow[k]);CHKERRQ(ierr);
263       for (l=0; l<c->nrows[k]; l++) {
264         col = c->columnsforrow[k][l];      /* global column index */
265 
266         c->vscaleforrow[k][l] = gtol[col]; /* local column index */
267       }
268     }
269     ierr = PetscFree(gtol);CHKERRQ(ierr);
270   }
271   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
272 
273   ierr = PetscFree(rowhit);CHKERRQ(ierr);
274   ierr = PetscFree(columnsforrow);CHKERRQ(ierr);
275   ierr = MatRestoreColumnIJ(aij->A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
276   ierr = MatRestoreColumnIJ(aij->B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
277   if (map) {ierr = ISLocalToGlobalMappingRestoreIndices(map,&ltog);CHKERRQ(ierr);}
278   PetscFunctionReturn(0);
279 }
280 
281 
282 
283 
284 
285 
286