xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision 7b6bb2c608b6fc6714ef38fda02c2dbb91c82665)
1 
2 #include <../src/mat/impls/aij/mpi/mpiaij.h>
3 
4 extern PetscErrorCode CreateColmap_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,*rows = 0,*A_ci,*A_cj,ncols,col;
14   const PetscInt        *is;
15   PetscInt              nis = iscoloring->n,nctot,*cols,*B_ci,*B_cj;
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               *ltog = (map ? map->indices : (PetscInt*) PETSC_NULL) ,ctype=c->ctype;
22 
23   PetscFunctionBegin;
24   if (!mat->assembled) SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_WRONGSTATE,"Matrix must be assembled first; MatAssemblyBegin/End();");
25   if (ctype == IS_COLORING_GHOSTED && !map) SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_INCOMP,"When using ghosted differencing matrix must have local to global mapping provided with MatSetLocalToGlobalMapping");
26 
27   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
28 
29   M                = mat->rmap->n;
30   cstart           = mat->cmap->rstart;
31   cend             = mat->cmap->rend;
32   c->M             = mat->rmap->N;  /* set the global rows and columns and local rows */
33   c->N             = mat->cmap->N;
34   c->m             = mat->rmap->n;
35   c->rstart        = mat->rmap->rstart;
36 
37   c->ncolors       = nis;
38   ierr             = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
39   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
40   ierr             = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
41   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->rows);CHKERRQ(ierr);
42   ierr             = PetscMalloc(nis*sizeof(PetscInt*),&c->columnsforrow);CHKERRQ(ierr);
43   ierr = PetscLogObjectMemory(c,5*nis*sizeof(PetscInt));CHKERRQ(ierr);
44 
45   /* Allow access to data structures of local part of matrix */
46   if (!aij->colmap) {
47     ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
48   }
49   ierr = MatGetColumnIJ(aij->A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
50   ierr = MatGetColumnIJ(aij->B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
51 
52   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&rowhit);CHKERRQ(ierr);
53   ierr = PetscMalloc((M+1)*sizeof(PetscInt),&columnsforrow);CHKERRQ(ierr);
54 
55   for (i=0; i<nis; i++) {
56     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
57     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
58     c->ncolumns[i] = n;
59     if (n) {
60       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
61       ierr = PetscLogObjectMemory(c,n*sizeof(PetscInt));CHKERRQ(ierr);
62       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
63     } else {
64       c->columns[i]  = 0;
65     }
66 
67     if (ctype == IS_COLORING_GLOBAL){
68       /* Determine the total (parallel) number of columns of this color */
69       ierr = MPI_Comm_size(((PetscObject)mat)->comm,&size);CHKERRQ(ierr);
70       ierr = PetscMalloc2(size,PetscMPIInt,&ncolsonproc,size,PetscMPIInt,&disp);CHKERRQ(ierr);
71 
72       nn   = PetscMPIIntCast(n);
73       ierr = MPI_Allgather(&nn,1,MPI_INT,ncolsonproc,1,MPI_INT,((PetscObject)mat)->comm);CHKERRQ(ierr);
74       nctot = 0; for (j=0; j<size; j++) {nctot += ncolsonproc[j];}
75       if (!nctot) {
76         ierr = PetscInfo(mat,"Coloring of matrix has some unneeded colors with no corresponding rows\n");CHKERRQ(ierr);
77       }
78 
79       disp[0] = 0;
80       for (j=1; j<size; j++) {
81         disp[j] = disp[j-1] + ncolsonproc[j-1];
82       }
83 
84       /* Get complete list of columns for color on each processor */
85       ierr = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
86       ierr = MPI_Allgatherv((void*)is,n,MPIU_INT,cols,ncolsonproc,disp,MPIU_INT,((PetscObject)mat)->comm);CHKERRQ(ierr);
87       ierr = PetscFree2(ncolsonproc,disp);CHKERRQ(ierr);
88     } else if (ctype == IS_COLORING_GHOSTED){
89       /* Determine local number of columns of this color on this process, including ghost points */
90       nctot = n;
91       ierr = PetscMalloc((nctot+1)*sizeof(PetscInt),&cols);CHKERRQ(ierr);
92       ierr = PetscMemcpy(cols,is,n*sizeof(PetscInt));CHKERRQ(ierr);
93     } else {
94       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Not provided for this MatFDColoring type");
95     }
96 
97     /*
98        Mark all rows affect by these columns
99     */
100     /* Temporary option to allow for debugging/testing */
101     flg  = PETSC_FALSE;
102     ierr = PetscOptionsGetBool(PETSC_NULL,"-matfdcoloring_slow",&flg,PETSC_NULL);CHKERRQ(ierr);
103     if (!flg) {/*-----------------------------------------------------------------------------*/
104       /* crude, fast version */
105       ierr = PetscMemzero(rowhit,M*sizeof(PetscInt));CHKERRQ(ierr);
106       /* loop over columns*/
107       for (j=0; j<nctot; j++) {
108         if (ctype == IS_COLORING_GHOSTED) {
109           col = ltog[cols[j]];
110         } else {
111           col  = cols[j];
112         }
113         if (col >= cstart && col < cend) {
114           /* column is in diagonal block of matrix */
115           rows = A_cj + A_ci[col-cstart];
116           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
117         } else {
118 #if defined (PETSC_USE_CTABLE)
119           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
120 	  colb --;
121 #else
122           colb = aij->colmap[col] - 1;
123 #endif
124           if (colb == -1) {
125             m = 0;
126           } else {
127             rows = B_cj + B_ci[colb];
128             m    = B_ci[colb+1] - B_ci[colb];
129           }
130         }
131         /* loop over columns marking them in rowhit */
132         for (k=0; k<m; k++) {
133           rowhit[*rows++] = col + 1;
134         }
135       }
136 
137       /* count the number of hits */
138       nrows = 0;
139       for (j=0; j<M; j++) {
140         if (rowhit[j]) nrows++;
141       }
142       c->nrows[i]         = nrows;
143       ierr                = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->rows[i]);CHKERRQ(ierr);
144       ierr                = PetscMalloc((nrows+1)*sizeof(PetscInt),&c->columnsforrow[i]);CHKERRQ(ierr);
145       ierr = PetscLogObjectMemory(c,2*(nrows+1)*sizeof(PetscInt));CHKERRQ(ierr);
146       nrows = 0;
147       for (j=0; j<M; j++) {
148         if (rowhit[j]) {
149           c->rows[i][nrows]           = j;
150           c->columnsforrow[i][nrows] = rowhit[j] - 1;
151           nrows++;
152         }
153       }
154     } else {/*-------------------------------------------------------------------------------*/
155       /* slow version, using rowhit as a linked list */
156       PetscInt currentcol,fm,mfm;
157       rowhit[M] = M;
158       nrows     = 0;
159       /* loop over columns*/
160       for (j=0; j<nctot; j++) {
161         if (ctype == IS_COLORING_GHOSTED) {
162           col = ltog[cols[j]];
163         } else {
164           col  = cols[j];
165         }
166         if (col >= cstart && col < cend) {
167           /* column is in diagonal block of matrix */
168           rows = A_cj + A_ci[col-cstart];
169           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
170         } else {
171 #if defined (PETSC_USE_CTABLE)
172           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
173           colb --;
174 #else
175           colb = aij->colmap[col] - 1;
176 #endif
177           if (colb == -1) {
178             m = 0;
179           } else {
180             rows = B_cj + B_ci[colb];
181             m    = B_ci[colb+1] - B_ci[colb];
182           }
183         }
184 
185         /* loop over columns marking them in rowhit */
186         fm    = M; /* fm points to first entry in linked list */
187         for (k=0; k<m; k++) {
188           currentcol = *rows++;
189 	  /* is it already in the list? */
190           do {
191             mfm  = fm;
192             fm   = rowhit[fm];
193           } while (fm < currentcol);
194           /* not in list so add it */
195           if (fm != currentcol) {
196             nrows++;
197             columnsforrow[currentcol] = col;
198             /* next three lines insert new entry into linked list */
199             rowhit[mfm]               = currentcol;
200             rowhit[currentcol]        = fm;
201             fm                        = currentcol;
202             /* fm points to present position in list since we know the columns are sorted */
203           } else {
204             SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Invalid coloring of matrix detected");
205           }
206         }
207       }
208       c->nrows[i]         = nrows;
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(((PetscObject)mat)->comm,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, *gtol;
254     ierr = PetscMalloc((N+1)*sizeof(PetscInt),&gtol);CHKERRQ(ierr);
255     for (i=0; i<N; i++) gtol[i] = -1;
256     for (i=0; i<map->n; i++) gtol[ltog[i]] = i;
257 
258     c->vscale = 0; /* will be created in MatFDColoringApply() */
259     ierr = PetscMalloc(c->ncolors*sizeof(PetscInt*),&c->vscaleforrow);CHKERRQ(ierr);
260     for (k=0; k<c->ncolors; k++) {
261       ierr = PetscMalloc((c->nrows[k]+1)*sizeof(PetscInt),&c->vscaleforrow[k]);CHKERRQ(ierr);
262       for (l=0; l<c->nrows[k]; l++) {
263         col = c->columnsforrow[k][l];      /* global column index */
264         c->vscaleforrow[k][l] = gtol[col]; /* local column index */
265       }
266     }
267     ierr = PetscFree(gtol);CHKERRQ(ierr);
268   }
269   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
270 
271   ierr = PetscFree(rowhit);CHKERRQ(ierr);
272   ierr = PetscFree(columnsforrow);CHKERRQ(ierr);
273   ierr = MatRestoreColumnIJ(aij->A,0,PETSC_FALSE,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
274   ierr = MatRestoreColumnIJ(aij->B,0,PETSC_FALSE,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
275   PetscFunctionReturn(0);
276 }
277 
278 
279 
280 
281 
282 
283