xref: /petsc/src/ksp/pc/impls/gamg/gamg.c (revision 4fc747eaadbeca11629f314a99edccbc2ed7b3d3)
1 /*
2  GAMG geometric-algebric multigrid PC - Mark Adams 2011
3  */
4 #include <petsc/private/matimpl.h>
5 #include <../src/ksp/pc/impls/gamg/gamg.h>           /*I "petscpc.h" I*/
6 #include <petsc/private/kspimpl.h>
7 #include <../src/ksp/pc/impls/bjacobi/bjacobi.h> /* Hack to access same_local_solves */
8 
9 #if defined PETSC_GAMG_USE_LOG
10 PetscLogEvent petsc_gamg_setup_events[NUM_SET];
11 #endif
12 
13 #if defined PETSC_USE_LOG
14 PetscLogEvent PC_GAMGGraph_AGG;
15 PetscLogEvent PC_GAMGGraph_GEO;
16 PetscLogEvent PC_GAMGCoarsen_AGG;
17 PetscLogEvent PC_GAMGCoarsen_GEO;
18 PetscLogEvent PC_GAMGProlongator_AGG;
19 PetscLogEvent PC_GAMGProlongator_GEO;
20 PetscLogEvent PC_GAMGOptProlongator_AGG;
21 #endif
22 
23 #define GAMG_MAXLEVELS 30
24 
25 /* #define GAMG_STAGES */
26 #if (defined PETSC_GAMG_USE_LOG && defined GAMG_STAGES)
27 static PetscLogStage gamg_stages[GAMG_MAXLEVELS];
28 #endif
29 
30 static PetscFunctionList GAMGList = 0;
31 static PetscBool PCGAMGPackageInitialized;
32 
33 /* ----------------------------------------------------------------------------- */
34 #undef __FUNCT__
35 #define __FUNCT__ "PCReset_GAMG"
36 PetscErrorCode PCReset_GAMG(PC pc)
37 {
38   PetscErrorCode ierr;
39   PC_MG          *mg      = (PC_MG*)pc->data;
40   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
41 
42   PetscFunctionBegin;
43   if (pc_gamg->data) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_PLIB,"This should not happen, cleaned up in SetUp\n");
44   pc_gamg->data_sz = 0;
45   ierr = PetscFree(pc_gamg->orig_data);CHKERRQ(ierr);
46   PetscFunctionReturn(0);
47 }
48 
49 /* -------------------------------------------------------------------------- */
50 /*
51    PCGAMGCreateLevel_GAMG: create coarse op with RAP.  repartition and/or reduce number
52      of active processors.
53 
54    Input Parameter:
55    . pc - parameters + side effect: coarse data in 'pc_gamg->data' and
56           'pc_gamg->data_sz' are changed via repartitioning/reduction.
57    . Amat_fine - matrix on this fine (k) level
58    . cr_bs - coarse block size
59    In/Output Parameter:
60    . a_P_inout - prolongation operator to the next level (k-->k-1)
61    . a_nactive_proc - number of active procs
62    Output Parameter:
63    . a_Amat_crs - coarse matrix that is created (k-1)
64 */
65 
66 #undef __FUNCT__
67 #define __FUNCT__ "PCGAMGCreateLevel_GAMG"
68 static PetscErrorCode PCGAMGCreateLevel_GAMG(PC pc,Mat Amat_fine,PetscInt cr_bs,Mat *a_P_inout,Mat *a_Amat_crs,PetscMPIInt *a_nactive_proc,IS * Pcolumnperm)
69 {
70   PetscErrorCode  ierr;
71   PC_MG           *mg         = (PC_MG*)pc->data;
72   PC_GAMG         *pc_gamg    = (PC_GAMG*)mg->innerctx;
73   Mat             Cmat,Pold=*a_P_inout;
74   MPI_Comm        comm;
75   PetscMPIInt     rank,size,new_size,nactive=*a_nactive_proc;
76   PetscInt        ncrs_eq,ncrs,f_bs;
77 
78   PetscFunctionBegin;
79   ierr = PetscObjectGetComm((PetscObject)Amat_fine,&comm);CHKERRQ(ierr);
80   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
81   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
82   ierr = MatGetBlockSize(Amat_fine, &f_bs);CHKERRQ(ierr);
83   ierr = MatPtAP(Amat_fine, Pold, MAT_INITIAL_MATRIX, 2.0, &Cmat);CHKERRQ(ierr);
84 
85   /* set 'ncrs' (nodes), 'ncrs_eq' (equations)*/
86   ierr = MatGetLocalSize(Cmat, &ncrs_eq, NULL);CHKERRQ(ierr);
87   if (pc_gamg->data_cell_rows>0) {
88     ncrs = pc_gamg->data_sz/pc_gamg->data_cell_cols/pc_gamg->data_cell_rows;
89   } else {
90     PetscInt  bs;
91     ierr = MatGetBlockSize(Cmat, &bs);CHKERRQ(ierr);
92     ncrs = ncrs_eq/bs;
93   }
94 
95   /* get number of PEs to make active 'new_size', reduce, can be any integer 1-P */
96   {
97     PetscInt ncrs_eq_glob;
98     ierr     = MatGetSize(Cmat, &ncrs_eq_glob, NULL);CHKERRQ(ierr);
99     new_size = (PetscMPIInt)((float)ncrs_eq_glob/(float)pc_gamg->min_eq_proc + 0.5); /* hardwire min. number of eq/proc */
100     if (!new_size) new_size = 1; /* not likely, posible? */
101     else if (new_size >= nactive) new_size = nactive; /* no change, rare */
102   }
103 
104   if (Pcolumnperm) *Pcolumnperm = NULL;
105 
106   if (!pc_gamg->repart && new_size==nactive) *a_Amat_crs = Cmat; /* output - no repartitioning or reduction - could bail here */
107   else {
108     PetscInt       *counts,*newproc_idx,ii,jj,kk,strideNew,*tidx,ncrs_new,ncrs_eq_new,nloc_old;
109     IS             is_eq_newproc,is_eq_num,is_eq_num_prim,new_eq_indices;
110 
111     nloc_old = ncrs_eq/cr_bs;
112     if (ncrs_eq % cr_bs) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"ncrs_eq %D not divisible by cr_bs %D",ncrs_eq,cr_bs);
113 #if defined PETSC_GAMG_USE_LOG
114     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET12],0,0,0,0);CHKERRQ(ierr);
115 #endif
116     /* make 'is_eq_newproc' */
117     ierr = PetscMalloc1(size, &counts);CHKERRQ(ierr);
118     if (pc_gamg->repart) {
119       /* Repartition Cmat_{k} and move colums of P^{k}_{k-1} and coordinates of primal part accordingly */
120       Mat adj;
121 
122      ierr = PetscInfo3(pc,"Repartition: size (active): %D --> %D, neq = %D\n",*a_nactive_proc,new_size,ncrs_eq);CHKERRQ(ierr);
123 
124       /* get 'adj' */
125       if (cr_bs == 1) {
126         ierr = MatConvert(Cmat, MATMPIADJ, MAT_INITIAL_MATRIX, &adj);CHKERRQ(ierr);
127       } else {
128         /* make a scalar matrix to partition (no Stokes here) */
129         Mat               tMat;
130         PetscInt          Istart_crs,Iend_crs,ncols,jj,Ii;
131         const PetscScalar *vals;
132         const PetscInt    *idx;
133         PetscInt          *d_nnz, *o_nnz, M, N;
134         static PetscInt   llev = 0;
135         MatType           mtype;
136 
137         ierr = PetscMalloc2(ncrs, &d_nnz,ncrs, &o_nnz);CHKERRQ(ierr);
138         ierr = MatGetOwnershipRange(Cmat, &Istart_crs, &Iend_crs);CHKERRQ(ierr);
139         ierr = MatGetSize(Cmat, &M, &N);CHKERRQ(ierr);
140         for (Ii = Istart_crs, jj = 0; Ii < Iend_crs; Ii += cr_bs, jj++) {
141           ierr      = MatGetRow(Cmat,Ii,&ncols,0,0);CHKERRQ(ierr);
142           d_nnz[jj] = ncols/cr_bs;
143           o_nnz[jj] = ncols/cr_bs;
144           ierr      = MatRestoreRow(Cmat,Ii,&ncols,0,0);CHKERRQ(ierr);
145           if (d_nnz[jj] > ncrs) d_nnz[jj] = ncrs;
146           if (o_nnz[jj] > (M/cr_bs-ncrs)) o_nnz[jj] = M/cr_bs-ncrs;
147         }
148 
149         ierr = MatGetType(Amat_fine,&mtype);CHKERRQ(ierr);
150         ierr = MatCreate(comm, &tMat);CHKERRQ(ierr);
151         ierr = MatSetSizes(tMat, ncrs, ncrs,PETSC_DETERMINE, PETSC_DETERMINE);CHKERRQ(ierr);
152         ierr = MatSetType(tMat,mtype);CHKERRQ(ierr);
153         ierr = MatSeqAIJSetPreallocation(tMat,0,d_nnz);CHKERRQ(ierr);
154         ierr = MatMPIAIJSetPreallocation(tMat,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
155         ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
156 
157         for (ii = Istart_crs; ii < Iend_crs; ii++) {
158           PetscInt dest_row = ii/cr_bs;
159           ierr = MatGetRow(Cmat,ii,&ncols,&idx,&vals);CHKERRQ(ierr);
160           for (jj = 0; jj < ncols; jj++) {
161             PetscInt    dest_col = idx[jj]/cr_bs;
162             PetscScalar v        = 1.0;
163             ierr = MatSetValues(tMat,1,&dest_row,1,&dest_col,&v,ADD_VALUES);CHKERRQ(ierr);
164           }
165           ierr = MatRestoreRow(Cmat,ii,&ncols,&idx,&vals);CHKERRQ(ierr);
166         }
167         ierr = MatAssemblyBegin(tMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
168         ierr = MatAssemblyEnd(tMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
169 
170         if (llev++ == -1) {
171           PetscViewer viewer; char fname[32];
172           ierr = PetscSNPrintf(fname,sizeof(fname),"part_mat_%D.mat",llev);CHKERRQ(ierr);
173           PetscViewerBinaryOpen(comm,fname,FILE_MODE_WRITE,&viewer);
174           ierr = MatView(tMat, viewer);CHKERRQ(ierr);
175           ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
176         }
177         ierr = MatConvert(tMat, MATMPIADJ, MAT_INITIAL_MATRIX, &adj);CHKERRQ(ierr);
178         ierr = MatDestroy(&tMat);CHKERRQ(ierr);
179       } /* create 'adj' */
180 
181       { /* partition: get newproc_idx */
182         char            prefix[256];
183         const char      *pcpre;
184         const PetscInt  *is_idx;
185         MatPartitioning mpart;
186         IS              proc_is;
187         PetscInt        targetPE;
188 
189         ierr = MatPartitioningCreate(comm, &mpart);CHKERRQ(ierr);
190         ierr = MatPartitioningSetAdjacency(mpart, adj);CHKERRQ(ierr);
191         ierr = PCGetOptionsPrefix(pc, &pcpre);CHKERRQ(ierr);
192         ierr = PetscSNPrintf(prefix,sizeof(prefix),"%spc_gamg_",pcpre ? pcpre : "");CHKERRQ(ierr);
193         ierr = PetscObjectSetOptionsPrefix((PetscObject)mpart,prefix);CHKERRQ(ierr);
194         ierr = MatPartitioningSetFromOptions(mpart);CHKERRQ(ierr);
195         ierr = MatPartitioningSetNParts(mpart, new_size);CHKERRQ(ierr);
196         ierr = MatPartitioningApply(mpart, &proc_is);CHKERRQ(ierr);
197         ierr = MatPartitioningDestroy(&mpart);CHKERRQ(ierr);
198 
199         /* collect IS info */
200         ierr     = PetscMalloc1(ncrs_eq, &newproc_idx);CHKERRQ(ierr);
201         ierr     = ISGetIndices(proc_is, &is_idx);CHKERRQ(ierr);
202         targetPE = 1; /* bring to "front" of machine */
203         /*targetPE = size/new_size;*/ /* spread partitioning across machine */
204         for (kk = jj = 0 ; kk < nloc_old ; kk++) {
205           for (ii = 0 ; ii < cr_bs ; ii++, jj++) {
206             newproc_idx[jj] = is_idx[kk] * targetPE; /* distribution */
207           }
208         }
209         ierr = ISRestoreIndices(proc_is, &is_idx);CHKERRQ(ierr);
210         ierr = ISDestroy(&proc_is);CHKERRQ(ierr);
211       }
212       ierr = MatDestroy(&adj);CHKERRQ(ierr);
213 
214       ierr = ISCreateGeneral(comm, ncrs_eq, newproc_idx, PETSC_COPY_VALUES, &is_eq_newproc);CHKERRQ(ierr);
215       ierr = PetscFree(newproc_idx);CHKERRQ(ierr);
216     } else { /* simple aggreagtion of parts -- 'is_eq_newproc' */
217       PetscInt rfactor,targetPE;
218 
219       /* find factor */
220       if (new_size == 1) rfactor = size; /* easy */
221       else {
222         PetscReal best_fact = 0.;
223         jj = -1;
224         for (kk = 1 ; kk <= size ; kk++) {
225           if (!(size%kk)) { /* a candidate */
226             PetscReal nactpe = (PetscReal)size/(PetscReal)kk, fact = nactpe/(PetscReal)new_size;
227             if (fact > 1.0) fact = 1./fact; /* keep fact < 1 */
228             if (fact > best_fact) {
229               best_fact = fact; jj = kk;
230             }
231           }
232         }
233         if (jj != -1) rfactor = jj;
234         else rfactor = 1; /* does this happen .. a prime */
235       }
236       new_size = size/rfactor;
237 
238       if (new_size==nactive) {
239         *a_Amat_crs = Cmat; /* output - no repartitioning or reduction, bail out because nested here */
240         ierr        = PetscFree(counts);CHKERRQ(ierr);
241         ierr = PetscInfo2(pc,"Aggregate processors noop: new_size=%D, neq(loc)=%D\n",new_size,ncrs_eq);CHKERRQ(ierr);
242 #if defined PETSC_GAMG_USE_LOG
243         ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET12],0,0,0,0);CHKERRQ(ierr);
244 #endif
245         PetscFunctionReturn(0);
246       }
247 
248       ierr = PetscInfo1(pc,"Number of equations (loc) %D with simple aggregation\n",ncrs_eq);CHKERRQ(ierr);
249       targetPE = rank/rfactor;
250       ierr     = ISCreateStride(comm, ncrs_eq, targetPE, 0, &is_eq_newproc);CHKERRQ(ierr);
251     } /* end simple 'is_eq_newproc' */
252 
253     /*
254      Create an index set from the is_eq_newproc index set to indicate the mapping TO
255      */
256     ierr = ISPartitioningToNumbering(is_eq_newproc, &is_eq_num);CHKERRQ(ierr);
257     is_eq_num_prim = is_eq_num;
258     /*
259       Determine how many equations/vertices are assigned to each processor
260      */
261     ierr        = ISPartitioningCount(is_eq_newproc, size, counts);CHKERRQ(ierr);
262     ncrs_eq_new = counts[rank];
263     ierr        = ISDestroy(&is_eq_newproc);CHKERRQ(ierr);
264     ncrs_new = ncrs_eq_new/cr_bs; /* eqs */
265 
266     ierr = PetscFree(counts);CHKERRQ(ierr);
267 #if defined PETSC_GAMG_USE_LOG
268     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET12],0,0,0,0);CHKERRQ(ierr);
269 #endif
270     /* data movement scope -- this could be moved to subclasses so that we don't try to cram all auxilary data into some complex abstracted thing */
271     {
272     Vec            src_crd, dest_crd;
273     const PetscInt *idx,ndata_rows=pc_gamg->data_cell_rows,ndata_cols=pc_gamg->data_cell_cols,node_data_sz=ndata_rows*ndata_cols;
274     VecScatter     vecscat;
275     PetscScalar    *array;
276     IS isscat;
277 
278     /* move data (for primal equations only) */
279     /* Create a vector to contain the newly ordered element information */
280     ierr = VecCreate(comm, &dest_crd);CHKERRQ(ierr);
281     ierr = VecSetSizes(dest_crd, node_data_sz*ncrs_new, PETSC_DECIDE);CHKERRQ(ierr);
282     ierr = VecSetType(dest_crd,VECSTANDARD);CHKERRQ(ierr); /* this is needed! */
283     /*
284      There are 'ndata_rows*ndata_cols' data items per node, (one can think of the vectors of having
285      a block size of ...).  Note, ISs are expanded into equation space by 'cr_bs'.
286      */
287     ierr = PetscMalloc1(ncrs*node_data_sz, &tidx);CHKERRQ(ierr);
288     ierr = ISGetIndices(is_eq_num_prim, &idx);CHKERRQ(ierr);
289     for (ii=0,jj=0; ii<ncrs; ii++) {
290       PetscInt id = idx[ii*cr_bs]/cr_bs; /* get node back */
291       for (kk=0; kk<node_data_sz; kk++, jj++) tidx[jj] = id*node_data_sz + kk;
292     }
293     ierr = ISRestoreIndices(is_eq_num_prim, &idx);CHKERRQ(ierr);
294     ierr = ISCreateGeneral(comm, node_data_sz*ncrs, tidx, PETSC_COPY_VALUES, &isscat);CHKERRQ(ierr);
295     ierr = PetscFree(tidx);CHKERRQ(ierr);
296     /*
297      Create a vector to contain the original vertex information for each element
298      */
299     ierr = VecCreateSeq(PETSC_COMM_SELF, node_data_sz*ncrs, &src_crd);CHKERRQ(ierr);
300     for (jj=0; jj<ndata_cols; jj++) {
301       const PetscInt stride0=ncrs*pc_gamg->data_cell_rows;
302       for (ii=0; ii<ncrs; ii++) {
303         for (kk=0; kk<ndata_rows; kk++) {
304           PetscInt    ix = ii*ndata_rows + kk + jj*stride0, jx = ii*node_data_sz + kk*ndata_cols + jj;
305           PetscScalar tt = (PetscScalar)pc_gamg->data[ix];
306           ierr = VecSetValues(src_crd, 1, &jx, &tt, INSERT_VALUES);CHKERRQ(ierr);
307         }
308       }
309     }
310     ierr = VecAssemblyBegin(src_crd);CHKERRQ(ierr);
311     ierr = VecAssemblyEnd(src_crd);CHKERRQ(ierr);
312     /*
313       Scatter the element vertex information (still in the original vertex ordering)
314       to the correct processor
315     */
316     ierr = VecScatterCreate(src_crd, NULL, dest_crd, isscat, &vecscat);CHKERRQ(ierr);
317     ierr = ISDestroy(&isscat);CHKERRQ(ierr);
318     ierr = VecScatterBegin(vecscat,src_crd,dest_crd,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
319     ierr = VecScatterEnd(vecscat,src_crd,dest_crd,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
320     ierr = VecScatterDestroy(&vecscat);CHKERRQ(ierr);
321     ierr = VecDestroy(&src_crd);CHKERRQ(ierr);
322     /*
323       Put the element vertex data into a new allocation of the gdata->ele
324     */
325     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
326     ierr = PetscMalloc1(node_data_sz*ncrs_new, &pc_gamg->data);CHKERRQ(ierr);
327 
328     pc_gamg->data_sz = node_data_sz*ncrs_new;
329     strideNew        = ncrs_new*ndata_rows;
330 
331     ierr = VecGetArray(dest_crd, &array);CHKERRQ(ierr);
332     for (jj=0; jj<ndata_cols; jj++) {
333       for (ii=0; ii<ncrs_new; ii++) {
334         for (kk=0; kk<ndata_rows; kk++) {
335           PetscInt ix = ii*ndata_rows + kk + jj*strideNew, jx = ii*node_data_sz + kk*ndata_cols + jj;
336           pc_gamg->data[ix] = PetscRealPart(array[jx]);
337         }
338       }
339     }
340     ierr = VecRestoreArray(dest_crd, &array);CHKERRQ(ierr);
341     ierr = VecDestroy(&dest_crd);CHKERRQ(ierr);
342     }
343     /* move A and P (columns) with new layout */
344 #if defined PETSC_GAMG_USE_LOG
345     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET13],0,0,0,0);CHKERRQ(ierr);
346 #endif
347 
348     /*
349       Invert for MatGetSubMatrix
350     */
351     ierr = ISInvertPermutation(is_eq_num, ncrs_eq_new, &new_eq_indices);CHKERRQ(ierr);
352     ierr = ISSort(new_eq_indices);CHKERRQ(ierr); /* is this needed? */
353     ierr = ISSetBlockSize(new_eq_indices, cr_bs);CHKERRQ(ierr);
354     if (is_eq_num != is_eq_num_prim) {
355       ierr = ISDestroy(&is_eq_num_prim);CHKERRQ(ierr); /* could be same as 'is_eq_num' */
356     }
357     if (Pcolumnperm) {
358       ierr = PetscObjectReference((PetscObject)new_eq_indices);CHKERRQ(ierr);
359       *Pcolumnperm = new_eq_indices;
360     }
361     ierr = ISDestroy(&is_eq_num);CHKERRQ(ierr);
362 #if defined PETSC_GAMG_USE_LOG
363     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET13],0,0,0,0);CHKERRQ(ierr);
364     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET14],0,0,0,0);CHKERRQ(ierr);
365 #endif
366     /* 'a_Amat_crs' output */
367     {
368       Mat mat;
369       ierr        = MatGetSubMatrix(Cmat, new_eq_indices, new_eq_indices, MAT_INITIAL_MATRIX, &mat);CHKERRQ(ierr);
370       *a_Amat_crs = mat;
371     }
372     ierr = MatDestroy(&Cmat);CHKERRQ(ierr);
373 
374 #if defined PETSC_GAMG_USE_LOG
375     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET14],0,0,0,0);CHKERRQ(ierr);
376 #endif
377     /* prolongator */
378     {
379       IS       findices;
380       PetscInt Istart,Iend;
381       Mat      Pnew;
382 
383       ierr = MatGetOwnershipRange(Pold, &Istart, &Iend);CHKERRQ(ierr);
384 #if defined PETSC_GAMG_USE_LOG
385       ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET15],0,0,0,0);CHKERRQ(ierr);
386 #endif
387       ierr = ISCreateStride(comm,Iend-Istart,Istart,1,&findices);CHKERRQ(ierr);
388       ierr = ISSetBlockSize(findices,f_bs);CHKERRQ(ierr);
389       ierr = MatGetSubMatrix(Pold, findices, new_eq_indices, MAT_INITIAL_MATRIX, &Pnew);CHKERRQ(ierr);
390       ierr = ISDestroy(&findices);CHKERRQ(ierr);
391 
392 #if defined PETSC_GAMG_USE_LOG
393       ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET15],0,0,0,0);CHKERRQ(ierr);
394 #endif
395       ierr = MatDestroy(a_P_inout);CHKERRQ(ierr);
396 
397       /* output - repartitioned */
398       *a_P_inout = Pnew;
399     }
400     ierr = ISDestroy(&new_eq_indices);CHKERRQ(ierr);
401 
402     *a_nactive_proc = new_size; /* output */
403   }
404   PetscFunctionReturn(0);
405 }
406 
407 /* -------------------------------------------------------------------------- */
408 /*
409    PCSetUp_GAMG - Prepares for the use of the GAMG preconditioner
410                     by setting data structures and options.
411 
412    Input Parameter:
413 .  pc - the preconditioner context
414 
415 */
416 #undef __FUNCT__
417 #define __FUNCT__ "PCSetUp_GAMG"
418 PetscErrorCode PCSetUp_GAMG(PC pc)
419 {
420   PetscErrorCode ierr;
421   PC_MG          *mg      = (PC_MG*)pc->data;
422   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
423   Mat            Pmat     = pc->pmat;
424   PetscInt       fine_level,level,level1,bs,M,qq,lidx,nASMBlocksArr[GAMG_MAXLEVELS];
425   MPI_Comm       comm;
426   PetscMPIInt    rank,size,nactivepe;
427   Mat            Aarr[GAMG_MAXLEVELS],Parr[GAMG_MAXLEVELS];
428   IS             *ASMLocalIDsArr[GAMG_MAXLEVELS];
429   PetscLogDouble nnz0=0.,nnztot=0.;
430   MatInfo        info;
431 
432   PetscFunctionBegin;
433   ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
434   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
435   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
436 
437   if (pc_gamg->setup_count++ > 0) {
438     if ((PetscBool)(!pc_gamg->reuse_prol)) {
439       /* reset everything */
440       ierr = PCReset_MG(pc);CHKERRQ(ierr);
441       pc->setupcalled = 0;
442     } else {
443       PC_MG_Levels **mglevels = mg->levels;
444       /* just do Galerkin grids */
445       Mat          B,dA,dB;
446 
447      if (!pc->setupcalled) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"PCSetUp() has not been called yet");
448       if (pc_gamg->Nlevels > 1) {
449         /* currently only handle case where mat and pmat are the same on coarser levels */
450         ierr = KSPGetOperators(mglevels[pc_gamg->Nlevels-1]->smoothd,&dA,&dB);CHKERRQ(ierr);
451         /* (re)set to get dirty flag */
452         ierr = KSPSetOperators(mglevels[pc_gamg->Nlevels-1]->smoothd,dA,dB);CHKERRQ(ierr);
453 
454         for (level=pc_gamg->Nlevels-2; level>=0; level--) {
455           /* the first time through the matrix structure has changed from repartitioning */
456           if (pc_gamg->setup_count==2) {
457             ierr = MatPtAP(dB,mglevels[level+1]->interpolate,MAT_INITIAL_MATRIX,1.0,&B);CHKERRQ(ierr);
458             ierr = MatDestroy(&mglevels[level]->A);CHKERRQ(ierr);
459 
460             mglevels[level]->A = B;
461           } else {
462             ierr = KSPGetOperators(mglevels[level]->smoothd,NULL,&B);CHKERRQ(ierr);
463             ierr = MatPtAP(dB,mglevels[level+1]->interpolate,MAT_REUSE_MATRIX,1.0,&B);CHKERRQ(ierr);
464           }
465           ierr = KSPSetOperators(mglevels[level]->smoothd,B,B);CHKERRQ(ierr);
466           dB   = B;
467         }
468       }
469 
470       ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
471       PetscFunctionReturn(0);
472     }
473   }
474 
475   if (!pc_gamg->data) {
476     if (pc_gamg->orig_data) {
477       ierr = MatGetBlockSize(Pmat, &bs);CHKERRQ(ierr);
478       ierr = MatGetLocalSize(Pmat, &qq, NULL);CHKERRQ(ierr);
479 
480       pc_gamg->data_sz        = (qq/bs)*pc_gamg->orig_data_cell_rows*pc_gamg->orig_data_cell_cols;
481       pc_gamg->data_cell_rows = pc_gamg->orig_data_cell_rows;
482       pc_gamg->data_cell_cols = pc_gamg->orig_data_cell_cols;
483 
484       ierr = PetscMalloc1(pc_gamg->data_sz, &pc_gamg->data);CHKERRQ(ierr);
485       for (qq=0; qq<pc_gamg->data_sz; qq++) pc_gamg->data[qq] = pc_gamg->orig_data[qq];
486     } else {
487       if (!pc_gamg->ops->createdefaultdata) SETERRQ(comm,PETSC_ERR_PLIB,"'createdefaultdata' not set(?) need to support NULL data");
488       ierr = pc_gamg->ops->createdefaultdata(pc,Pmat);CHKERRQ(ierr);
489     }
490   }
491 
492   /* cache original data for reuse */
493   if (!pc_gamg->orig_data && (PetscBool)(!pc_gamg->reuse_prol)) {
494     ierr = PetscMalloc1(pc_gamg->data_sz, &pc_gamg->orig_data);CHKERRQ(ierr);
495     for (qq=0; qq<pc_gamg->data_sz; qq++) pc_gamg->orig_data[qq] = pc_gamg->data[qq];
496     pc_gamg->orig_data_cell_rows = pc_gamg->data_cell_rows;
497     pc_gamg->orig_data_cell_cols = pc_gamg->data_cell_cols;
498   }
499 
500   /* get basic dims */
501   ierr = MatGetBlockSize(Pmat, &bs);CHKERRQ(ierr);
502   ierr = MatGetSize(Pmat, &M, &qq);CHKERRQ(ierr);
503 
504   ierr = MatGetInfo(Pmat,MAT_GLOBAL_SUM,&info);CHKERRQ(ierr); /* global reduction */
505   nnz0   = info.nz_used;
506   nnztot = info.nz_used;
507   ierr = PetscInfo6(pc,"level %d) N=%D, n data rows=%d, n data cols=%d, nnz/row (ave)=%d, np=%d\n",0,M,pc_gamg->data_cell_rows,pc_gamg->data_cell_cols,(int)(nnz0/(PetscReal)M+0.5),size);CHKERRQ(ierr);
508 
509   /* Get A_i and R_i */
510   for (level=0, Aarr[0]=Pmat, nactivepe = size; level < (pc_gamg->Nlevels-1) && (!level || M>pc_gamg->coarse_eq_limit); level++) {
511     pc_gamg->current_level = level;
512     level1 = level + 1;
513 #if defined PETSC_GAMG_USE_LOG
514     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET1],0,0,0,0);CHKERRQ(ierr);
515 #if (defined GAMG_STAGES)
516     ierr = PetscLogStagePush(gamg_stages[level]);CHKERRQ(ierr);
517 #endif
518 #endif
519     { /* construct prolongator */
520       Mat              Gmat;
521       PetscCoarsenData *agg_lists;
522       Mat              Prol11;
523 
524       ierr = pc_gamg->ops->graph(pc,Aarr[level], &Gmat);CHKERRQ(ierr);
525       ierr = pc_gamg->ops->coarsen(pc, &Gmat, &agg_lists);CHKERRQ(ierr);
526       ierr = pc_gamg->ops->prolongator(pc,Aarr[level],Gmat,agg_lists,&Prol11);CHKERRQ(ierr);
527 
528       /* could have failed to create new level */
529       if (Prol11) {
530         /* get new block size of coarse matrices */
531         ierr = MatGetBlockSizes(Prol11, NULL, &bs);CHKERRQ(ierr);
532 
533         if (pc_gamg->ops->optprolongator) {
534           /* smooth */
535           ierr = pc_gamg->ops->optprolongator(pc, Aarr[level], &Prol11);CHKERRQ(ierr);
536         }
537 
538         Parr[level1] = Prol11;
539       } else Parr[level1] = NULL;
540 
541       if (pc_gamg->use_aggs_in_gasm) {
542         PetscInt bs;
543         ierr = MatGetBlockSizes(Prol11, &bs, NULL);CHKERRQ(ierr);
544         ierr = PetscCDGetASMBlocks(agg_lists, bs, &nASMBlocksArr[level], &ASMLocalIDsArr[level]);CHKERRQ(ierr);
545       }
546 
547       ierr = MatDestroy(&Gmat);CHKERRQ(ierr);
548       ierr = PetscCDDestroy(agg_lists);CHKERRQ(ierr);
549     } /* construct prolongator scope */
550 #if defined PETSC_GAMG_USE_LOG
551     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET1],0,0,0,0);CHKERRQ(ierr);
552 #endif
553     if (!level) Aarr[0] = Pmat; /* use Pmat for finest level setup */
554     if (!Parr[level1]) {
555       ierr =  PetscInfo1(pc,"Stop gridding, level %D\n",level);CHKERRQ(ierr);
556 #if defined PETSC_GAMG_USE_LOG && defined GAMG_STAGES
557       ierr = PetscLogStagePop();CHKERRQ(ierr);
558 #endif
559       break;
560     }
561 #if defined PETSC_GAMG_USE_LOG
562     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET2],0,0,0,0);CHKERRQ(ierr);
563 #endif
564 
565     ierr = pc_gamg->ops->createlevel(pc, Aarr[level], bs,&Parr[level1], &Aarr[level1], &nactivepe, NULL);CHKERRQ(ierr);
566 
567 #if defined PETSC_GAMG_USE_LOG
568     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET2],0,0,0,0);CHKERRQ(ierr);
569 #endif
570     ierr = MatGetSize(Aarr[level1], &M, &qq);CHKERRQ(ierr);
571     ierr = MatGetInfo(Aarr[level1], MAT_GLOBAL_SUM, &info);CHKERRQ(ierr);
572     nnztot += info.nz_used;
573     ierr = PetscInfo5(pc,"%d) N=%D, n data cols=%d, nnz/row (ave)=%d, %d active pes\n",level1,M,pc_gamg->data_cell_cols,(int)(info.nz_used/(PetscReal)M),nactivepe);CHKERRQ(ierr);
574 
575 #if (defined PETSC_GAMG_USE_LOG && defined GAMG_STAGES)
576     ierr = PetscLogStagePop();CHKERRQ(ierr);
577 #endif
578     /* stop if one node or one proc -- could pull back for singular problems */
579     if ( (pc_gamg->data_cell_cols && M/pc_gamg->data_cell_cols < 2) || (!pc_gamg->data_cell_cols && M/bs < 2) ) {
580       ierr =  PetscInfo2(pc,"HARD stop of coarsening on level %D.  Grid too small: %D block nodes\n",level,M/bs);CHKERRQ(ierr);
581       level++;
582       break;
583     }
584   } /* levels */
585   ierr                  = PetscFree(pc_gamg->data);CHKERRQ(ierr);
586 
587   ierr = PetscInfo2(pc,"%D levels, grid complexity = %g\n",level+1,nnztot/nnz0);CHKERRQ(ierr);
588   pc_gamg->Nlevels = level + 1;
589   fine_level       = level;
590   ierr             = PCMGSetLevels(pc,pc_gamg->Nlevels,NULL);CHKERRQ(ierr);
591 
592   if (pc_gamg->Nlevels > 1) { /* don't setup MG if one level */
593     /* set default smoothers & set operators */
594     for (lidx = 1, level = pc_gamg->Nlevels-2; lidx <= fine_level; lidx++, level--) {
595       KSP smoother;
596       PC  subpc;
597 
598       ierr = PCMGGetSmoother(pc, lidx, &smoother);CHKERRQ(ierr);
599       ierr = KSPGetPC(smoother, &subpc);CHKERRQ(ierr);
600 
601       ierr = KSPSetNormType(smoother, KSP_NORM_NONE);CHKERRQ(ierr);
602       /* set ops */
603       ierr = KSPSetOperators(smoother, Aarr[level], Aarr[level]);CHKERRQ(ierr);
604       ierr = PCMGSetInterpolation(pc, lidx, Parr[level+1]);CHKERRQ(ierr);
605 
606       /* set defaults */
607       ierr = KSPSetType(smoother, KSPCHEBYSHEV);CHKERRQ(ierr);
608 
609       /* set blocks for GASM smoother that uses the 'aggregates' */
610       if (pc_gamg->use_aggs_in_gasm) {
611         PetscInt sz;
612         IS       *is;
613 
614         sz   = nASMBlocksArr[level];
615         is   = ASMLocalIDsArr[level];
616         ierr = PCSetType(subpc, PCGASM);CHKERRQ(ierr);
617         ierr = PCGASMSetOverlap(subpc, 0);CHKERRQ(ierr);
618         if (!sz) {
619           IS       is;
620           PetscInt my0,kk;
621           ierr = MatGetOwnershipRange(Aarr[level], &my0, &kk);CHKERRQ(ierr);
622           ierr = ISCreateGeneral(PETSC_COMM_SELF, 1, &my0, PETSC_COPY_VALUES, &is);CHKERRQ(ierr);
623           ierr = PCGASMSetSubdomains(subpc, 1, &is, NULL);CHKERRQ(ierr);
624           ierr = ISDestroy(&is);CHKERRQ(ierr);
625         } else {
626           PetscInt kk;
627           ierr = PCGASMSetSubdomains(subpc, sz, is, NULL);CHKERRQ(ierr);
628           for (kk=0; kk<sz; kk++) {
629             ierr = ISDestroy(&is[kk]);CHKERRQ(ierr);
630           }
631           ierr = PetscFree(is);CHKERRQ(ierr);
632         }
633         ASMLocalIDsArr[level] = NULL;
634         nASMBlocksArr[level]  = 0;
635         ierr                  = PCGASMSetType(subpc, PC_GASM_BASIC);CHKERRQ(ierr);
636       } else {
637         ierr = PCSetType(subpc, PCSOR);CHKERRQ(ierr);
638       }
639     }
640     {
641       /* coarse grid */
642       KSP smoother,*k2; PC subpc,pc2; PetscInt ii,first;
643       Mat Lmat = Aarr[(level=pc_gamg->Nlevels-1)]; lidx = 0;
644       ierr = PCMGGetSmoother(pc, lidx, &smoother);CHKERRQ(ierr);
645       ierr = KSPSetOperators(smoother, Lmat, Lmat);CHKERRQ(ierr);
646       ierr = KSPSetNormType(smoother, KSP_NORM_NONE);CHKERRQ(ierr);
647       ierr = KSPGetPC(smoother, &subpc);CHKERRQ(ierr);
648       ierr = PCSetType(subpc, PCBJACOBI);CHKERRQ(ierr);
649       ierr = PCSetUp(subpc);CHKERRQ(ierr);
650       ierr = PCBJacobiGetSubKSP(subpc,&ii,&first,&k2);CHKERRQ(ierr);
651       if (ii != 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"ii %D is not one",ii);
652       ierr = KSPGetPC(k2[0],&pc2);CHKERRQ(ierr);
653       ierr = PCSetType(pc2, PCLU);CHKERRQ(ierr);
654       ierr = PCFactorSetShiftType(pc2,MAT_SHIFT_INBLOCKS);CHKERRQ(ierr);
655       ierr = KSPSetTolerances(k2[0],PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,1);CHKERRQ(ierr);
656       ierr = KSPSetType(k2[0], KSPPREONLY);CHKERRQ(ierr);
657       /* This flag gets reset by PCBJacobiGetSubKSP(), but our BJacobi really does the same algorithm everywhere (and in
658        * fact, all but one process will have zero dofs), so we reset the flag to avoid having PCView_BJacobi attempt to
659        * view every subdomain as though they were different. */
660       ((PC_BJacobi*)subpc->data)->same_local_solves = PETSC_TRUE;
661     }
662 
663     /* should be called in PCSetFromOptions_GAMG(), but cannot be called prior to PCMGSetLevels() */
664     ierr = PetscObjectOptionsBegin((PetscObject)pc);CHKERRQ(ierr);
665     ierr = PCSetFromOptions_MG(PetscOptionsObject,pc);CHKERRQ(ierr);
666     ierr = PetscOptionsEnd();CHKERRQ(ierr);
667     if (!mg->galerkin) SETERRQ(comm,PETSC_ERR_USER,"PCGAMG must use Galerkin for coarse operators.");
668     if (mg->galerkin == 1) mg->galerkin = 2;
669 
670     /* clean up */
671     for (level=1; level<pc_gamg->Nlevels; level++) {
672       ierr = MatDestroy(&Parr[level]);CHKERRQ(ierr);
673       ierr = MatDestroy(&Aarr[level]);CHKERRQ(ierr);
674     }
675     ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
676   } else {
677     KSP smoother;
678     ierr = PetscInfo(pc,"One level solver used (system is seen as DD). Using default solver.\n");CHKERRQ(ierr);
679     ierr = PCMGGetSmoother(pc, 0, &smoother);CHKERRQ(ierr);
680     ierr = KSPSetOperators(smoother, Aarr[0], Aarr[0]);CHKERRQ(ierr);
681     ierr = KSPSetType(smoother, KSPPREONLY);CHKERRQ(ierr);
682     ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
683   }
684   PetscFunctionReturn(0);
685 }
686 
687 /* ------------------------------------------------------------------------- */
688 /*
689  PCDestroy_GAMG - Destroys the private context for the GAMG preconditioner
690    that was created with PCCreate_GAMG().
691 
692    Input Parameter:
693 .  pc - the preconditioner context
694 
695    Application Interface Routine: PCDestroy()
696 */
697 #undef __FUNCT__
698 #define __FUNCT__ "PCDestroy_GAMG"
699 PetscErrorCode PCDestroy_GAMG(PC pc)
700 {
701   PetscErrorCode ierr;
702   PC_MG          *mg     = (PC_MG*)pc->data;
703   PC_GAMG        *pc_gamg= (PC_GAMG*)mg->innerctx;
704 
705   PetscFunctionBegin;
706   ierr = PCReset_GAMG(pc);CHKERRQ(ierr);
707   if (pc_gamg->ops->destroy) {
708     ierr = (*pc_gamg->ops->destroy)(pc);CHKERRQ(ierr);
709   }
710   ierr = PetscRandomDestroy(&pc_gamg->random);CHKERRQ(ierr);
711   ierr = PetscFree(pc_gamg->ops);CHKERRQ(ierr);
712   ierr = PetscFree(pc_gamg->gamg_type_name);CHKERRQ(ierr);
713   ierr = PetscFree(pc_gamg);CHKERRQ(ierr);
714   ierr = PCDestroy_MG(pc);CHKERRQ(ierr);
715   PetscFunctionReturn(0);
716 }
717 
718 #undef __FUNCT__
719 #define __FUNCT__ "PCGAMGSetProcEqLim"
720 /*@
721    PCGAMGSetProcEqLim - Set number of equations to aim for on coarse grids via processor reduction.
722 
723    Logically Collective on PC
724 
725    Input Parameters:
726 +  pc - the preconditioner context
727 -  n - the number of equations
728 
729 
730    Options Database Key:
731 .  -pc_gamg_process_eq_limit <limit>
732 
733    Level: intermediate
734 
735    Concepts: Unstructured multigrid preconditioner
736 
737 .seealso: PCGAMGSetCoarseEqLim()
738 @*/
739 PetscErrorCode  PCGAMGSetProcEqLim(PC pc, PetscInt n)
740 {
741   PetscErrorCode ierr;
742 
743   PetscFunctionBegin;
744   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
745   ierr = PetscTryMethod(pc,"PCGAMGSetProcEqLim_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
746   PetscFunctionReturn(0);
747 }
748 
749 #undef __FUNCT__
750 #define __FUNCT__ "PCGAMGSetProcEqLim_GAMG"
751 static PetscErrorCode PCGAMGSetProcEqLim_GAMG(PC pc, PetscInt n)
752 {
753   PC_MG   *mg      = (PC_MG*)pc->data;
754   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
755 
756   PetscFunctionBegin;
757   if (n>0) pc_gamg->min_eq_proc = n;
758   PetscFunctionReturn(0);
759 }
760 
761 #undef __FUNCT__
762 #define __FUNCT__ "PCGAMGSetCoarseEqLim"
763 /*@
764    PCGAMGSetCoarseEqLim - Set max number of equations on coarse grids.
765 
766  Collective on PC
767 
768    Input Parameters:
769 +  pc - the preconditioner context
770 -  n - maximum number of equations to aim for
771 
772    Options Database Key:
773 .  -pc_gamg_coarse_eq_limit <limit>
774 
775    Level: intermediate
776 
777    Concepts: Unstructured multigrid preconditioner
778 
779 .seealso: PCGAMGSetProcEqLim()
780 @*/
781 PetscErrorCode PCGAMGSetCoarseEqLim(PC pc, PetscInt n)
782 {
783   PetscErrorCode ierr;
784 
785   PetscFunctionBegin;
786   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
787   ierr = PetscTryMethod(pc,"PCGAMGSetCoarseEqLim_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
788   PetscFunctionReturn(0);
789 }
790 
791 #undef __FUNCT__
792 #define __FUNCT__ "PCGAMGSetCoarseEqLim_GAMG"
793 static PetscErrorCode PCGAMGSetCoarseEqLim_GAMG(PC pc, PetscInt n)
794 {
795   PC_MG   *mg      = (PC_MG*)pc->data;
796   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
797 
798   PetscFunctionBegin;
799   if (n>0) pc_gamg->coarse_eq_limit = n;
800   PetscFunctionReturn(0);
801 }
802 
803 #undef __FUNCT__
804 #define __FUNCT__ "PCGAMGSetRepartitioning"
805 /*@
806    PCGAMGSetRepartitioning - Repartition the coarse grids
807 
808    Collective on PC
809 
810    Input Parameters:
811 +  pc - the preconditioner context
812 -  n - PETSC_TRUE or PETSC_FALSE
813 
814    Options Database Key:
815 .  -pc_gamg_repartition <true,false>
816 
817    Level: intermediate
818 
819    Concepts: Unstructured multigrid preconditioner
820 
821 .seealso: ()
822 @*/
823 PetscErrorCode PCGAMGSetRepartitioning(PC pc, PetscBool n)
824 {
825   PetscErrorCode ierr;
826 
827   PetscFunctionBegin;
828   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
829   ierr = PetscTryMethod(pc,"PCGAMGSetRepartitioning_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
830   PetscFunctionReturn(0);
831 }
832 
833 #undef __FUNCT__
834 #define __FUNCT__ "PCGAMGSetRepartitioning_GAMG"
835 static PetscErrorCode PCGAMGSetRepartitioning_GAMG(PC pc, PetscBool n)
836 {
837   PC_MG   *mg      = (PC_MG*)pc->data;
838   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
839 
840   PetscFunctionBegin;
841   pc_gamg->repart = n;
842   PetscFunctionReturn(0);
843 }
844 
845 #undef __FUNCT__
846 #define __FUNCT__ "PCGAMGSetReuseInterpolation"
847 /*@
848    PCGAMGSetReuseInterpolation - Reuse prolongation when rebuilding preconditioner
849 
850    Collective on PC
851 
852    Input Parameters:
853 +  pc - the preconditioner context
854 -  n - PETSC_TRUE or PETSC_FALSE
855 
856    Options Database Key:
857 .  -pc_gamg_reuse_interpolation <true,false>
858 
859    Level: intermediate
860 
861    Concepts: Unstructured multigrid preconditioner
862 
863 .seealso: ()
864 @*/
865 PetscErrorCode PCGAMGSetReuseInterpolation(PC pc, PetscBool n)
866 {
867   PetscErrorCode ierr;
868 
869   PetscFunctionBegin;
870   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
871   ierr = PetscTryMethod(pc,"PCGAMGSetReuseInterpolation_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
872   PetscFunctionReturn(0);
873 }
874 
875 #undef __FUNCT__
876 #define __FUNCT__ "PCGAMGSetReuseInterpolation_GAMG"
877 static PetscErrorCode PCGAMGSetReuseInterpolation_GAMG(PC pc, PetscBool n)
878 {
879   PC_MG   *mg      = (PC_MG*)pc->data;
880   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
881 
882   PetscFunctionBegin;
883   pc_gamg->reuse_prol = n;
884   PetscFunctionReturn(0);
885 }
886 
887 #undef __FUNCT__
888 #define __FUNCT__ "PCGAMGSetUseASMAggs"
889 /*@
890    PCGAMGSetUseASMAggs -
891 
892    Collective on PC
893 
894    Input Parameters:
895 .  pc - the preconditioner context
896 
897 
898    Options Database Key:
899 .  -pc_gamg_use_agg_gasm
900 
901    Level: intermediate
902 
903    Concepts: Unstructured multigrid preconditioner
904 
905 .seealso: ()
906 @*/
907 PetscErrorCode PCGAMGSetUseASMAggs(PC pc, PetscBool n)
908 {
909   PetscErrorCode ierr;
910 
911   PetscFunctionBegin;
912   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
913   ierr = PetscTryMethod(pc,"PCGAMGSetUseASMAggs_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
914   PetscFunctionReturn(0);
915 }
916 
917 #undef __FUNCT__
918 #define __FUNCT__ "PCGAMGSetUseASMAggs_GAMG"
919 static PetscErrorCode PCGAMGSetUseASMAggs_GAMG(PC pc, PetscBool n)
920 {
921   PC_MG   *mg      = (PC_MG*)pc->data;
922   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
923 
924   PetscFunctionBegin;
925   pc_gamg->use_aggs_in_gasm = n;
926   PetscFunctionReturn(0);
927 }
928 
929 #undef __FUNCT__
930 #define __FUNCT__ "PCGAMGSetNlevels"
931 /*@
932    PCGAMGSetNlevels -  Sets the maximum number of levels PCGAMG will use
933 
934    Not collective on PC
935 
936    Input Parameters:
937 +  pc - the preconditioner
938 -  n - the maximum number of levels to use
939 
940    Options Database Key:
941 .  -pc_mg_levels
942 
943    Level: intermediate
944 
945    Concepts: Unstructured multigrid preconditioner
946 
947 .seealso: ()
948 @*/
949 PetscErrorCode PCGAMGSetNlevels(PC pc, PetscInt n)
950 {
951   PetscErrorCode ierr;
952 
953   PetscFunctionBegin;
954   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
955   ierr = PetscTryMethod(pc,"PCGAMGSetNlevels_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
956   PetscFunctionReturn(0);
957 }
958 
959 #undef __FUNCT__
960 #define __FUNCT__ "PCGAMGSetNlevels_GAMG"
961 static PetscErrorCode PCGAMGSetNlevels_GAMG(PC pc, PetscInt n)
962 {
963   PC_MG   *mg      = (PC_MG*)pc->data;
964   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
965 
966   PetscFunctionBegin;
967   pc_gamg->Nlevels = n;
968   PetscFunctionReturn(0);
969 }
970 
971 #undef __FUNCT__
972 #define __FUNCT__ "PCGAMGSetThreshold"
973 /*@
974    PCGAMGSetThreshold - Relative threshold to use for dropping edges in aggregation graph
975 
976    Not collective on PC
977 
978    Input Parameters:
979 +  pc - the preconditioner context
980 -  threshold - the threshold value, 0.0 means keep all nonzero entries in the graph; negative means keep even zero entries in the graph
981 
982    Options Database Key:
983 .  -pc_gamg_threshold <threshold>
984 
985    Level: intermediate
986 
987    Concepts: Unstructured multigrid preconditioner
988 
989 .seealso: ()
990 @*/
991 PetscErrorCode PCGAMGSetThreshold(PC pc, PetscReal n)
992 {
993   PetscErrorCode ierr;
994 
995   PetscFunctionBegin;
996   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
997   ierr = PetscTryMethod(pc,"PCGAMGSetThreshold_C",(PC,PetscReal),(pc,n));CHKERRQ(ierr);
998   PetscFunctionReturn(0);
999 }
1000 
1001 #undef __FUNCT__
1002 #define __FUNCT__ "PCGAMGSetThreshold_GAMG"
1003 static PetscErrorCode PCGAMGSetThreshold_GAMG(PC pc, PetscReal n)
1004 {
1005   PC_MG   *mg      = (PC_MG*)pc->data;
1006   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
1007 
1008   PetscFunctionBegin;
1009   pc_gamg->threshold = n;
1010   PetscFunctionReturn(0);
1011 }
1012 
1013 #undef __FUNCT__
1014 #define __FUNCT__ "PCGAMGSetType"
1015 /*@
1016    PCGAMGSetType - Set solution method
1017 
1018    Collective on PC
1019 
1020    Input Parameters:
1021 +  pc - the preconditioner context
1022 -  type - PCGAMGAGG, PCGAMGGEO, or PCGAMGCLASSICAL
1023 
1024    Options Database Key:
1025 .  -pc_gamg_type <agg,geo,classical>
1026 
1027    Level: intermediate
1028 
1029    Concepts: Unstructured multigrid preconditioner
1030 
1031 .seealso: PCGAMGGetType(), PCGAMG
1032 @*/
1033 PetscErrorCode PCGAMGSetType(PC pc, PCGAMGType type)
1034 {
1035   PetscErrorCode ierr;
1036 
1037   PetscFunctionBegin;
1038   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
1039   ierr = PetscTryMethod(pc,"PCGAMGSetType_C",(PC,PCGAMGType),(pc,type));CHKERRQ(ierr);
1040   PetscFunctionReturn(0);
1041 }
1042 
1043 #undef __FUNCT__
1044 #define __FUNCT__ "PCGAMGGetType"
1045 /*@
1046    PCGAMGGetType - Get solution method
1047 
1048    Collective on PC
1049 
1050    Input Parameter:
1051 .  pc - the preconditioner context
1052 
1053    Output Parameter:
1054 .  type - the type of algorithm used
1055 
1056    Level: intermediate
1057 
1058    Concepts: Unstructured multigrid preconditioner
1059 
1060 .seealso: PCGAMGSetType(), PCGAMGType
1061 @*/
1062 PetscErrorCode PCGAMGGetType(PC pc, PCGAMGType *type)
1063 {
1064   PetscErrorCode ierr;
1065 
1066   PetscFunctionBegin;
1067   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
1068   ierr = PetscUseMethod(pc,"PCGAMGGetType_C",(PC,PCGAMGType*),(pc,type));CHKERRQ(ierr);
1069   PetscFunctionReturn(0);
1070 }
1071 
1072 #undef __FUNCT__
1073 #define __FUNCT__ "PCGAMGGetType_GAMG"
1074 static PetscErrorCode PCGAMGGetType_GAMG(PC pc, PCGAMGType *type)
1075 {
1076   PC_MG          *mg      = (PC_MG*)pc->data;
1077   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1078 
1079   PetscFunctionBegin;
1080   *type = pc_gamg->type;
1081   PetscFunctionReturn(0);
1082 }
1083 
1084 #undef __FUNCT__
1085 #define __FUNCT__ "PCGAMGSetType_GAMG"
1086 static PetscErrorCode PCGAMGSetType_GAMG(PC pc, PCGAMGType type)
1087 {
1088   PetscErrorCode ierr,(*r)(PC);
1089   PC_MG          *mg      = (PC_MG*)pc->data;
1090   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1091 
1092   PetscFunctionBegin;
1093   pc_gamg->type = type;
1094   ierr = PetscFunctionListFind(GAMGList,type,&r);CHKERRQ(ierr);
1095   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unknown GAMG type %s given",type);
1096   if (pc_gamg->ops->destroy) {
1097     ierr = (*pc_gamg->ops->destroy)(pc);CHKERRQ(ierr);
1098     ierr = PetscMemzero(pc_gamg->ops,sizeof(struct _PCGAMGOps));CHKERRQ(ierr);
1099     pc_gamg->ops->createlevel = PCGAMGCreateLevel_GAMG;
1100     /* cleaning up common data in pc_gamg - this should disapear someday */
1101     pc_gamg->data_cell_cols = 0;
1102     pc_gamg->data_cell_rows = 0;
1103     pc_gamg->orig_data_cell_cols = 0;
1104     pc_gamg->orig_data_cell_rows = 0;
1105     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
1106     pc_gamg->data_sz = 0;
1107   }
1108   ierr = PetscFree(pc_gamg->gamg_type_name);CHKERRQ(ierr);
1109   ierr = PetscStrallocpy(type,&pc_gamg->gamg_type_name);CHKERRQ(ierr);
1110   ierr = (*r)(pc);CHKERRQ(ierr);
1111   PetscFunctionReturn(0);
1112 }
1113 
1114 #undef __FUNCT__
1115 #define __FUNCT__ "PCView_GAMG"
1116 static PetscErrorCode PCView_GAMG(PC pc,PetscViewer viewer)
1117 {
1118   PetscErrorCode ierr;
1119   PC_MG          *mg      = (PC_MG*)pc->data;
1120   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1121 
1122   PetscFunctionBegin;
1123   ierr = PetscViewerASCIIPrintf(viewer,"    GAMG specific options\n");CHKERRQ(ierr);
1124   ierr = PetscViewerASCIIPrintf(viewer,"      Threshold for dropping small values from graph %g\n",(double)pc_gamg->threshold);CHKERRQ(ierr);
1125   if (pc_gamg->ops->view) {
1126     ierr = (*pc_gamg->ops->view)(pc,viewer);CHKERRQ(ierr);
1127   }
1128   PetscFunctionReturn(0);
1129 }
1130 
1131 #undef __FUNCT__
1132 #define __FUNCT__ "PCSetFromOptions_GAMG"
1133 PetscErrorCode PCSetFromOptions_GAMG(PetscOptionItems *PetscOptionsObject,PC pc)
1134 {
1135   PetscErrorCode ierr;
1136   PC_MG          *mg      = (PC_MG*)pc->data;
1137   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1138   PetscBool      flag;
1139   MPI_Comm       comm;
1140   char           prefix[256];
1141   const char     *pcpre;
1142 
1143   PetscFunctionBegin;
1144   ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
1145   ierr = PetscOptionsHead(PetscOptionsObject,"GAMG options");CHKERRQ(ierr);
1146   {
1147     char tname[256];
1148     ierr = PetscOptionsFList("-pc_gamg_type","Type of AMG method","PCGAMGSetType",GAMGList, pc_gamg->gamg_type_name, tname, sizeof(tname), &flag);CHKERRQ(ierr);
1149     if (flag) {
1150       ierr = PCGAMGSetType(pc,tname);CHKERRQ(ierr);
1151     }
1152     ierr = PetscOptionsBool("-pc_gamg_repartition","Repartion coarse grids","PCGAMGRepartitioning",pc_gamg->repart,&pc_gamg->repart,NULL);CHKERRQ(ierr);
1153     ierr = PetscOptionsBool("-pc_gamg_reuse_interpolation","Reuse prolongation operator","PCGAMGReuseInterpolation",pc_gamg->reuse_prol,&pc_gamg->reuse_prol,NULL);CHKERRQ(ierr);
1154     ierr = PetscOptionsBool("-pc_gamg_use_agg_gasm","Use aggregation agragates for GASM smoother","PCGAMGUseASMAggs",pc_gamg->use_aggs_in_gasm,&pc_gamg->use_aggs_in_gasm,NULL);CHKERRQ(ierr);
1155     ierr = PetscOptionsInt("-pc_gamg_process_eq_limit","Limit (goal) on number of equations per process on coarse grids","PCGAMGSetProcEqLim",pc_gamg->min_eq_proc,&pc_gamg->min_eq_proc,NULL);CHKERRQ(ierr);
1156     ierr = PetscOptionsInt("-pc_gamg_coarse_eq_limit","Limit on number of equations for the coarse grid","PCGAMGSetCoarseEqLim",pc_gamg->coarse_eq_limit,&pc_gamg->coarse_eq_limit,NULL);CHKERRQ(ierr);
1157     ierr = PetscOptionsReal("-pc_gamg_threshold","Relative threshold to use for dropping edges in aggregation graph","PCGAMGSetThreshold",pc_gamg->threshold,&pc_gamg->threshold,&flag);CHKERRQ(ierr);
1158     ierr = PetscOptionsInt("-pc_mg_levels","Set number of MG levels","PCGAMGSetNlevels",pc_gamg->Nlevels,&pc_gamg->Nlevels,NULL);CHKERRQ(ierr);
1159 
1160     /* set options for subtype */
1161     if (pc_gamg->ops->setfromoptions) {ierr = (*pc_gamg->ops->setfromoptions)(PetscOptionsObject,pc);CHKERRQ(ierr);}
1162   }
1163   ierr = PCGetOptionsPrefix(pc, &pcpre);CHKERRQ(ierr);
1164   ierr = PetscSNPrintf(prefix,sizeof(prefix),"%spc_gamg_",pcpre ? pcpre : "");CHKERRQ(ierr);
1165   ierr = PetscObjectSetOptionsPrefix((PetscObject)pc_gamg->random,prefix);CHKERRQ(ierr);
1166   ierr = PetscRandomSetFromOptions(pc_gamg->random);CHKERRQ(ierr);
1167   ierr = PetscOptionsTail();CHKERRQ(ierr);
1168   PetscFunctionReturn(0);
1169 }
1170 
1171 /* -------------------------------------------------------------------------- */
1172 /*MC
1173      PCGAMG - Geometric algebraic multigrid (AMG) preconditioner
1174 
1175    Options Database Keys:
1176    Multigrid options(inherited)
1177 +  -pc_mg_cycles <v>: v or w (PCMGSetCycleType())
1178 .  -pc_mg_smoothup <1>: Number of post-smoothing steps (PCMGSetNumberSmoothUp)
1179 .  -pc_mg_smoothdown <1>: Number of pre-smoothing steps (PCMGSetNumberSmoothDown)
1180 -  -pc_mg_type <multiplicative>: (one of) additive multiplicative full kascade
1181 
1182 
1183   Notes: In order to obtain good performance for PCGAMG for vector valued problems you must
1184 $       Call MatSetBlockSize() to indicate the number of degrees of freedom per grid point
1185 $       Call MatSetNearNullSpace() (or PCSetCoordinates() if solving the equations of elasticity) to indicate the near null space of the operator
1186 $       See the Users Manual Chapter 4 for more details
1187 
1188   Level: intermediate
1189 
1190   Concepts: algebraic multigrid
1191 
1192 .seealso:  PCCreate(), PCSetType(), MatSetBlockSize(), PCMGType, PCSetCoordinates(), MatSetNearNullSpace(), PCGAMGSetType(), PCGAMGAGG, PCGAMGGEO, PCGAMGCLASSICAL, PCGAMGSetProcEqLim(),
1193            PCGAMGSetCoarseEqLim(), PCGAMGSetRepartitioning(), PCGAMGRegister(), PCGAMGSetReuseInterpolation(), PCGAMGSetUseASMAggs(), PCGAMGSetNlevels(), PCGAMGSetThreshold(), PCGAMGGetType()
1194 M*/
1195 
1196 #undef __FUNCT__
1197 #define __FUNCT__ "PCCreate_GAMG"
1198 PETSC_EXTERN PetscErrorCode PCCreate_GAMG(PC pc)
1199 {
1200   PetscErrorCode ierr;
1201   PC_GAMG        *pc_gamg;
1202   PC_MG          *mg;
1203 
1204   PetscFunctionBegin;
1205   /* register AMG type */
1206   ierr = PCGAMGInitializePackage();CHKERRQ(ierr);
1207 
1208   /* PCGAMG is an inherited class of PCMG. Initialize pc as PCMG */
1209   ierr = PCSetType(pc, PCMG);CHKERRQ(ierr);
1210   ierr = PetscObjectChangeTypeName((PetscObject)pc, PCGAMG);CHKERRQ(ierr);
1211 
1212   /* create a supporting struct and attach it to pc */
1213   ierr         = PetscNewLog(pc,&pc_gamg);CHKERRQ(ierr);
1214   mg           = (PC_MG*)pc->data;
1215   mg->galerkin = 2;             /* Use Galerkin, but it is computed externally from PCMG by GAMG code */
1216   mg->innerctx = pc_gamg;
1217 
1218   ierr = PetscNewLog(pc,&pc_gamg->ops);CHKERRQ(ierr);
1219 
1220   pc_gamg->setup_count = 0;
1221   /* these should be in subctx but repartitioning needs simple arrays */
1222   pc_gamg->data_sz = 0;
1223   pc_gamg->data    = 0;
1224 
1225   /* overwrite the pointers of PCMG by the functions of base class PCGAMG */
1226   pc->ops->setfromoptions = PCSetFromOptions_GAMG;
1227   pc->ops->setup          = PCSetUp_GAMG;
1228   pc->ops->reset          = PCReset_GAMG;
1229   pc->ops->destroy        = PCDestroy_GAMG;
1230   mg->view                = PCView_GAMG;
1231 
1232   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetProcEqLim_C",PCGAMGSetProcEqLim_GAMG);CHKERRQ(ierr);
1233   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetCoarseEqLim_C",PCGAMGSetCoarseEqLim_GAMG);CHKERRQ(ierr);
1234   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetRepartitioning_C",PCGAMGSetRepartitioning_GAMG);CHKERRQ(ierr);
1235   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetReuseInterpolation_C",PCGAMGSetReuseInterpolation_GAMG);CHKERRQ(ierr);
1236   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetUseASMAggs_C",PCGAMGSetUseASMAggs_GAMG);CHKERRQ(ierr);
1237   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetThreshold_C",PCGAMGSetThreshold_GAMG);CHKERRQ(ierr);
1238   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetType_C",PCGAMGSetType_GAMG);CHKERRQ(ierr);
1239   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGGetType_C",PCGAMGGetType_GAMG);CHKERRQ(ierr);
1240   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetNlevels_C",PCGAMGSetNlevels_GAMG);CHKERRQ(ierr);
1241   pc_gamg->repart           = PETSC_FALSE;
1242   pc_gamg->reuse_prol       = PETSC_FALSE;
1243   pc_gamg->use_aggs_in_gasm = PETSC_FALSE;
1244   pc_gamg->min_eq_proc      = 50;
1245   pc_gamg->coarse_eq_limit  = 50;
1246   pc_gamg->threshold        = 0.;
1247   pc_gamg->Nlevels          = GAMG_MAXLEVELS;
1248   pc_gamg->current_level    = 0; /* don't need to init really */
1249   pc_gamg->ops->createlevel = PCGAMGCreateLevel_GAMG;
1250 
1251   ierr = PetscRandomCreate(PetscObjectComm((PetscObject)pc),&pc_gamg->random);CHKERRQ(ierr);
1252 
1253   /* PCSetUp_GAMG assumes that the type has been set, so set it to the default now */
1254   ierr = PCGAMGSetType(pc,PCGAMGAGG);CHKERRQ(ierr);
1255   PetscFunctionReturn(0);
1256 }
1257 
1258 #undef __FUNCT__
1259 #define __FUNCT__ "PCGAMGInitializePackage"
1260 /*@C
1261  PCGAMGInitializePackage - This function initializes everything in the PCGAMG package. It is called
1262     from PetscDLLibraryRegister() when using dynamic libraries, and on the first call to PCCreate_GAMG()
1263     when using static libraries.
1264 
1265  Level: developer
1266 
1267  .keywords: PC, PCGAMG, initialize, package
1268  .seealso: PetscInitialize()
1269 @*/
1270 PetscErrorCode PCGAMGInitializePackage(void)
1271 {
1272   PetscErrorCode ierr;
1273 
1274   PetscFunctionBegin;
1275   if (PCGAMGPackageInitialized) PetscFunctionReturn(0);
1276   PCGAMGPackageInitialized = PETSC_TRUE;
1277   ierr = PetscFunctionListAdd(&GAMGList,PCGAMGGEO,PCCreateGAMG_GEO);CHKERRQ(ierr);
1278   ierr = PetscFunctionListAdd(&GAMGList,PCGAMGAGG,PCCreateGAMG_AGG);CHKERRQ(ierr);
1279   ierr = PetscFunctionListAdd(&GAMGList,PCGAMGCLASSICAL,PCCreateGAMG_Classical);CHKERRQ(ierr);
1280   ierr = PetscRegisterFinalize(PCGAMGFinalizePackage);CHKERRQ(ierr);
1281 
1282   /* general events */
1283   ierr = PetscLogEventRegister("PCGAMGGraph_AGG", 0, &PC_GAMGGraph_AGG);CHKERRQ(ierr);
1284   ierr = PetscLogEventRegister("PCGAMGGraph_GEO", PC_CLASSID, &PC_GAMGGraph_GEO);CHKERRQ(ierr);
1285   ierr = PetscLogEventRegister("PCGAMGCoarse_AGG", PC_CLASSID, &PC_GAMGCoarsen_AGG);CHKERRQ(ierr);
1286   ierr = PetscLogEventRegister("PCGAMGCoarse_GEO", PC_CLASSID, &PC_GAMGCoarsen_GEO);CHKERRQ(ierr);
1287   ierr = PetscLogEventRegister("PCGAMGProl_AGG", PC_CLASSID, &PC_GAMGProlongator_AGG);CHKERRQ(ierr);
1288   ierr = PetscLogEventRegister("PCGAMGProl_GEO", PC_CLASSID, &PC_GAMGProlongator_GEO);CHKERRQ(ierr);
1289   ierr = PetscLogEventRegister("PCGAMGPOpt_AGG", PC_CLASSID, &PC_GAMGOptProlongator_AGG);CHKERRQ(ierr);
1290 
1291 #if defined PETSC_GAMG_USE_LOG
1292   ierr = PetscLogEventRegister("GAMG: createProl", PC_CLASSID, &petsc_gamg_setup_events[SET1]);CHKERRQ(ierr);
1293   ierr = PetscLogEventRegister("  Graph", PC_CLASSID, &petsc_gamg_setup_events[GRAPH]);CHKERRQ(ierr);
1294   /* PetscLogEventRegister("    G.Mat", PC_CLASSID, &petsc_gamg_setup_events[GRAPH_MAT]); */
1295   /* PetscLogEventRegister("    G.Filter", PC_CLASSID, &petsc_gamg_setup_events[GRAPH_FILTER]); */
1296   /* PetscLogEventRegister("    G.Square", PC_CLASSID, &petsc_gamg_setup_events[GRAPH_SQR]); */
1297   ierr = PetscLogEventRegister("  MIS/Agg", PC_CLASSID, &petsc_gamg_setup_events[SET4]);CHKERRQ(ierr);
1298   ierr = PetscLogEventRegister("  geo: growSupp", PC_CLASSID, &petsc_gamg_setup_events[SET5]);CHKERRQ(ierr);
1299   ierr = PetscLogEventRegister("  geo: triangle", PC_CLASSID, &petsc_gamg_setup_events[SET6]);CHKERRQ(ierr);
1300   ierr = PetscLogEventRegister("    search-set", PC_CLASSID, &petsc_gamg_setup_events[FIND_V]);CHKERRQ(ierr);
1301   ierr = PetscLogEventRegister("  SA: col data", PC_CLASSID, &petsc_gamg_setup_events[SET7]);CHKERRQ(ierr);
1302   ierr = PetscLogEventRegister("  SA: frmProl0", PC_CLASSID, &petsc_gamg_setup_events[SET8]);CHKERRQ(ierr);
1303   ierr = PetscLogEventRegister("  SA: smooth", PC_CLASSID, &petsc_gamg_setup_events[SET9]);CHKERRQ(ierr);
1304   ierr = PetscLogEventRegister("GAMG: partLevel", PC_CLASSID, &petsc_gamg_setup_events[SET2]);CHKERRQ(ierr);
1305   ierr = PetscLogEventRegister("  repartition", PC_CLASSID, &petsc_gamg_setup_events[SET12]);CHKERRQ(ierr);
1306   ierr = PetscLogEventRegister("  Invert-Sort", PC_CLASSID, &petsc_gamg_setup_events[SET13]);CHKERRQ(ierr);
1307   ierr = PetscLogEventRegister("  Move A", PC_CLASSID, &petsc_gamg_setup_events[SET14]);CHKERRQ(ierr);
1308   ierr = PetscLogEventRegister("  Move P", PC_CLASSID, &petsc_gamg_setup_events[SET15]);CHKERRQ(ierr);
1309 
1310   /* PetscLogEventRegister(" PL move data", PC_CLASSID, &petsc_gamg_setup_events[SET13]); */
1311   /* PetscLogEventRegister("GAMG: fix", PC_CLASSID, &petsc_gamg_setup_events[SET10]); */
1312   /* PetscLogEventRegister("GAMG: set levels", PC_CLASSID, &petsc_gamg_setup_events[SET11]); */
1313   /* create timer stages */
1314 #if defined GAMG_STAGES
1315   {
1316     char     str[32];
1317     PetscInt lidx;
1318     sprintf(str,"MG Level %d (finest)",0);
1319     ierr = PetscLogStageRegister(str, &gamg_stages[0]);CHKERRQ(ierr);
1320     for (lidx=1; lidx<9; lidx++) {
1321       sprintf(str,"MG Level %d",lidx);
1322       ierr = PetscLogStageRegister(str, &gamg_stages[lidx]);CHKERRQ(ierr);
1323     }
1324   }
1325 #endif
1326 #endif
1327   PetscFunctionReturn(0);
1328 }
1329 
1330 #undef __FUNCT__
1331 #define __FUNCT__ "PCGAMGFinalizePackage"
1332 /*@C
1333  PCGAMGFinalizePackage - This function frees everything from the PCGAMG package. It is
1334     called from PetscFinalize() automatically.
1335 
1336  Level: developer
1337 
1338  .keywords: Petsc, destroy, package
1339  .seealso: PetscFinalize()
1340 @*/
1341 PetscErrorCode PCGAMGFinalizePackage(void)
1342 {
1343   PetscErrorCode ierr;
1344 
1345   PetscFunctionBegin;
1346   PCGAMGPackageInitialized = PETSC_FALSE;
1347   ierr = PetscFunctionListDestroy(&GAMGList);CHKERRQ(ierr);
1348   PetscFunctionReturn(0);
1349 }
1350 
1351 #undef __FUNCT__
1352 #define __FUNCT__ "PCGAMGRegister"
1353 /*@C
1354  PCGAMGRegister - Register a PCGAMG implementation.
1355 
1356  Input Parameters:
1357  + type - string that will be used as the name of the GAMG type.
1358  - create - function for creating the gamg context.
1359 
1360   Level: advanced
1361 
1362  .seealso: PCGAMGType, PCGAMG, PCGAMGSetType()
1363 @*/
1364 PetscErrorCode PCGAMGRegister(PCGAMGType type, PetscErrorCode (*create)(PC))
1365 {
1366   PetscErrorCode ierr;
1367 
1368   PetscFunctionBegin;
1369   ierr = PCGAMGInitializePackage();CHKERRQ(ierr);
1370   ierr = PetscFunctionListAdd(&GAMGList,type,create);CHKERRQ(ierr);
1371   PetscFunctionReturn(0);
1372 }
1373 
1374