xref: /petsc/src/ksp/pc/impls/gamg/gamg.c (revision dced61a5cfeeeda68dfa4ee3e53b34d3cfb8da9f)
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) { /* this should not happen, cleaned up in SetUp */
44     PetscPrintf(PetscObjectComm((PetscObject)pc),"***[%d]%s this should not happen, cleaned up in SetUp\n",0,__FUNCT__);
45     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
46   }
47   pc_gamg->data_sz = 0;
48   ierr = PetscFree(pc_gamg->orig_data);CHKERRQ(ierr);
49   PetscFunctionReturn(0);
50 }
51 
52 /* -------------------------------------------------------------------------- */
53 /*
54    PCGAMGCreateLevel_GAMG: create coarse op with RAP.  repartition and/or reduce number
55      of active processors.
56 
57    Input Parameter:
58    . pc - parameters + side effect: coarse data in 'pc_gamg->data' and
59           'pc_gamg->data_sz' are changed via repartitioning/reduction.
60    . Amat_fine - matrix on this fine (k) level
61    . cr_bs - coarse block size
62    In/Output Parameter:
63    . a_P_inout - prolongation operator to the next level (k-->k-1)
64    . a_nactive_proc - number of active procs
65    Output Parameter:
66    . a_Amat_crs - coarse matrix that is created (k-1)
67 */
68 
69 #undef __FUNCT__
70 #define __FUNCT__ "PCGAMGCreateLevel_GAMG"
71 static PetscErrorCode PCGAMGCreateLevel_GAMG(PC pc,Mat Amat_fine,PetscInt cr_bs,
72                                   Mat *a_P_inout,Mat *a_Amat_crs,PetscMPIInt *a_nactive_proc,
73                                   IS * Pcolumnperm)
74 {
75   PetscErrorCode  ierr;
76   PC_MG           *mg         = (PC_MG*)pc->data;
77   PC_GAMG         *pc_gamg    = (PC_GAMG*)mg->innerctx;
78   Mat             Cmat,Pold=*a_P_inout;
79   MPI_Comm        comm;
80   PetscMPIInt     rank,size,new_size,nactive=*a_nactive_proc;
81   PetscInt        ncrs_eq,ncrs,f_bs;
82 
83   PetscFunctionBegin;
84   ierr = PetscObjectGetComm((PetscObject)Amat_fine,&comm);CHKERRQ(ierr);
85   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
86   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
87   ierr = MatGetBlockSize(Amat_fine, &f_bs);CHKERRQ(ierr);
88   ierr = MatPtAP(Amat_fine, Pold, MAT_INITIAL_MATRIX, 2.0, &Cmat);CHKERRQ(ierr);
89 
90   /* set 'ncrs' (nodes), 'ncrs_eq' (equations)*/
91   ierr = MatGetLocalSize(Cmat, &ncrs_eq, NULL);CHKERRQ(ierr);
92   if (pc_gamg->data_cell_rows>0) {
93     ncrs = pc_gamg->data_sz/pc_gamg->data_cell_cols/pc_gamg->data_cell_rows;
94   } else {
95     PetscInt  bs;
96     ierr = MatGetBlockSize(Cmat, &bs);CHKERRQ(ierr);
97     ncrs = ncrs_eq/bs;
98   }
99 
100   /* get number of PEs to make active 'new_size', reduce, can be any integer 1-P */
101   {
102     PetscInt ncrs_eq_glob;
103     ierr     = MatGetSize(Cmat, &ncrs_eq_glob, NULL);CHKERRQ(ierr);
104     new_size = (PetscMPIInt)((float)ncrs_eq_glob/(float)pc_gamg->min_eq_proc + 0.5); /* hardwire min. number of eq/proc */
105     if (!new_size) new_size = 1; /* not likely, posible? */
106     else if (new_size >= nactive) new_size = nactive; /* no change, rare */
107   }
108 
109   if (Pcolumnperm) *Pcolumnperm = NULL;
110 
111   if (!pc_gamg->repart && new_size==nactive) *a_Amat_crs = Cmat; /* output - no repartitioning or reduction - could bail here */
112   else {
113     PetscInt       *counts,*newproc_idx,ii,jj,kk,strideNew,*tidx,ncrs_new,ncrs_eq_new,nloc_old;
114     IS             is_eq_newproc,is_eq_num,is_eq_num_prim,new_eq_indices;
115 
116     nloc_old = ncrs_eq/cr_bs;
117     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);
118 #if defined PETSC_GAMG_USE_LOG
119     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET12],0,0,0,0);CHKERRQ(ierr);
120 #endif
121     /* make 'is_eq_newproc' */
122     ierr = PetscMalloc1(size, &counts);CHKERRQ(ierr);
123     if (pc_gamg->repart) {
124       /* Repartition Cmat_{k} and move colums of P^{k}_{k-1} and coordinates of primal part accordingly */
125       Mat adj;
126 
127      ierr = PetscInfo3(pc,"Repartition: size (active): %D --> %D, neq = %D\n",*a_nactive_proc,new_size,ncrs_eq);CHKERRQ(ierr);
128 
129       /* get 'adj' */
130       if (cr_bs == 1) {
131         ierr = MatConvert(Cmat, MATMPIADJ, MAT_INITIAL_MATRIX, &adj);CHKERRQ(ierr);
132       } else {
133         /* make a scalar matrix to partition (no Stokes here) */
134         Mat               tMat;
135         PetscInt          Istart_crs,Iend_crs,ncols,jj,Ii;
136         const PetscScalar *vals;
137         const PetscInt    *idx;
138         PetscInt          *d_nnz, *o_nnz, M, N;
139         static PetscInt   llev = 0;
140         MatType           mtype;
141 
142         ierr = PetscMalloc2(ncrs, &d_nnz,ncrs, &o_nnz);CHKERRQ(ierr);
143         ierr = MatGetOwnershipRange(Cmat, &Istart_crs, &Iend_crs);CHKERRQ(ierr);
144         ierr = MatGetSize(Cmat, &M, &N);CHKERRQ(ierr);
145         for (Ii = Istart_crs, jj = 0; Ii < Iend_crs; Ii += cr_bs, jj++) {
146           ierr      = MatGetRow(Cmat,Ii,&ncols,0,0);CHKERRQ(ierr);
147           d_nnz[jj] = ncols/cr_bs;
148           o_nnz[jj] = ncols/cr_bs;
149           ierr      = MatRestoreRow(Cmat,Ii,&ncols,0,0);CHKERRQ(ierr);
150           if (d_nnz[jj] > ncrs) d_nnz[jj] = ncrs;
151           if (o_nnz[jj] > (M/cr_bs-ncrs)) o_nnz[jj] = M/cr_bs-ncrs;
152         }
153 
154         ierr = MatGetType(Amat_fine,&mtype);CHKERRQ(ierr);
155         ierr = MatCreate(comm, &tMat);CHKERRQ(ierr);
156         ierr = MatSetSizes(tMat, ncrs, ncrs,PETSC_DETERMINE, PETSC_DETERMINE);CHKERRQ(ierr);
157         ierr = MatSetType(tMat,mtype);CHKERRQ(ierr);
158         ierr = MatSeqAIJSetPreallocation(tMat,0,d_nnz);CHKERRQ(ierr);
159         ierr = MatMPIAIJSetPreallocation(tMat,0,d_nnz,0,o_nnz);CHKERRQ(ierr);
160         ierr = PetscFree2(d_nnz,o_nnz);CHKERRQ(ierr);
161 
162         for (ii = Istart_crs; ii < Iend_crs; ii++) {
163           PetscInt dest_row = ii/cr_bs;
164           ierr = MatGetRow(Cmat,ii,&ncols,&idx,&vals);CHKERRQ(ierr);
165           for (jj = 0; jj < ncols; jj++) {
166             PetscInt    dest_col = idx[jj]/cr_bs;
167             PetscScalar v        = 1.0;
168             ierr = MatSetValues(tMat,1,&dest_row,1,&dest_col,&v,ADD_VALUES);CHKERRQ(ierr);
169           }
170           ierr = MatRestoreRow(Cmat,ii,&ncols,&idx,&vals);CHKERRQ(ierr);
171         }
172         ierr = MatAssemblyBegin(tMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
173         ierr = MatAssemblyEnd(tMat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
174 
175         if (llev++ == -1) {
176           PetscViewer viewer; char fname[32];
177           ierr = PetscSNPrintf(fname,sizeof(fname),"part_mat_%D.mat",llev);CHKERRQ(ierr);
178           PetscViewerBinaryOpen(comm,fname,FILE_MODE_WRITE,&viewer);
179           ierr = MatView(tMat, viewer);CHKERRQ(ierr);
180           ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
181         }
182 
183         ierr = MatConvert(tMat, MATMPIADJ, MAT_INITIAL_MATRIX, &adj);CHKERRQ(ierr);
184 
185         ierr = MatDestroy(&tMat);CHKERRQ(ierr);
186       } /* create 'adj' */
187 
188       { /* partition: get newproc_idx */
189         char            prefix[256];
190         const char      *pcpre;
191         const PetscInt  *is_idx;
192         MatPartitioning mpart;
193         IS              proc_is;
194         PetscInt        targetPE;
195 
196         ierr = MatPartitioningCreate(comm, &mpart);CHKERRQ(ierr);
197         ierr = MatPartitioningSetAdjacency(mpart, adj);CHKERRQ(ierr);
198         ierr = PCGetOptionsPrefix(pc, &pcpre);CHKERRQ(ierr);
199         ierr = PetscSNPrintf(prefix,sizeof(prefix),"%spc_gamg_",pcpre ? pcpre : "");CHKERRQ(ierr);
200         ierr = PetscObjectSetOptionsPrefix((PetscObject)mpart,prefix);CHKERRQ(ierr);
201         ierr = MatPartitioningSetFromOptions(mpart);CHKERRQ(ierr);
202         ierr = MatPartitioningSetNParts(mpart, new_size);CHKERRQ(ierr);
203         ierr = MatPartitioningApply(mpart, &proc_is);CHKERRQ(ierr);
204         ierr = MatPartitioningDestroy(&mpart);CHKERRQ(ierr);
205 
206         /* collect IS info */
207         ierr     = PetscMalloc1(ncrs_eq, &newproc_idx);CHKERRQ(ierr);
208         ierr     = ISGetIndices(proc_is, &is_idx);CHKERRQ(ierr);
209         targetPE = 1; /* bring to "front" of machine */
210         /*targetPE = size/new_size;*/ /* spread partitioning across machine */
211         for (kk = jj = 0 ; kk < nloc_old ; kk++) {
212           for (ii = 0 ; ii < cr_bs ; ii++, jj++) {
213             newproc_idx[jj] = is_idx[kk] * targetPE; /* distribution */
214           }
215         }
216         ierr = ISRestoreIndices(proc_is, &is_idx);CHKERRQ(ierr);
217         ierr = ISDestroy(&proc_is);CHKERRQ(ierr);
218       }
219       ierr = MatDestroy(&adj);CHKERRQ(ierr);
220 
221       ierr = ISCreateGeneral(comm, ncrs_eq, newproc_idx, PETSC_COPY_VALUES, &is_eq_newproc);CHKERRQ(ierr);
222       ierr = PetscFree(newproc_idx);CHKERRQ(ierr);
223     } else { /* simple aggreagtion of parts -- 'is_eq_newproc' */
224 
225       PetscInt rfactor,targetPE;
226       /* find factor */
227       if (new_size == 1) rfactor = size; /* easy */
228       else {
229         PetscReal best_fact = 0.;
230         jj = -1;
231         for (kk = 1 ; kk <= size ; kk++) {
232           if (!(size%kk)) { /* a candidate */
233             PetscReal nactpe = (PetscReal)size/(PetscReal)kk, fact = nactpe/(PetscReal)new_size;
234             if (fact > 1.0) fact = 1./fact; /* keep fact < 1 */
235             if (fact > best_fact) {
236               best_fact = fact; jj = kk;
237             }
238           }
239         }
240         if (jj != -1) rfactor = jj;
241         else rfactor = 1; /* does this happen .. a prime */
242       }
243       new_size = size/rfactor;
244 
245       if (new_size==nactive) {
246         *a_Amat_crs = Cmat; /* output - no repartitioning or reduction, bail out because nested here */
247         ierr        = PetscFree(counts);CHKERRQ(ierr);
248         ierr = PetscInfo2(pc,"Aggregate processors noop: new_size=%D, neq(loc)=%D\n",new_size,ncrs_eq);CHKERRQ(ierr);
249         PetscFunctionReturn(0);
250       }
251 
252       ierr = PetscInfo1(pc,"Number of equations (loc) %D with simple aggregation\n",ncrs_eq);CHKERRQ(ierr);
253       targetPE = rank/rfactor;
254       ierr     = ISCreateStride(comm, ncrs_eq, targetPE, 0, &is_eq_newproc);CHKERRQ(ierr);
255     } /* end simple 'is_eq_newproc' */
256 
257     /*
258      Create an index set from the is_eq_newproc index set to indicate the mapping TO
259      */
260     ierr = ISPartitioningToNumbering(is_eq_newproc, &is_eq_num);CHKERRQ(ierr);
261     is_eq_num_prim = is_eq_num;
262     /*
263       Determine how many equations/vertices are assigned to each processor
264      */
265     ierr        = ISPartitioningCount(is_eq_newproc, size, counts);CHKERRQ(ierr);
266     ncrs_eq_new = counts[rank];
267     ierr        = ISDestroy(&is_eq_newproc);CHKERRQ(ierr);
268     ncrs_new = ncrs_eq_new/cr_bs; /* eqs */
269 
270     ierr = PetscFree(counts);CHKERRQ(ierr);
271 #if defined PETSC_GAMG_USE_LOG
272     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET12],0,0,0,0);CHKERRQ(ierr);
273 #endif
274     /* 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 */
275     {
276     Vec            src_crd, dest_crd;
277     const PetscInt *idx,ndata_rows=pc_gamg->data_cell_rows,ndata_cols=pc_gamg->data_cell_cols,node_data_sz=ndata_rows*ndata_cols;
278     VecScatter     vecscat;
279     PetscScalar    *array;
280     IS isscat;
281 
282     /* move data (for primal equations only) */
283     /* Create a vector to contain the newly ordered element information */
284     ierr = VecCreate(comm, &dest_crd);CHKERRQ(ierr);
285     ierr = VecSetSizes(dest_crd, node_data_sz*ncrs_new, PETSC_DECIDE);CHKERRQ(ierr);
286     ierr = VecSetType(dest_crd,VECSTANDARD);CHKERRQ(ierr); /* this is needed! */
287     /*
288      There are 'ndata_rows*ndata_cols' data items per node, (one can think of the vectors of having
289      a block size of ...).  Note, ISs are expanded into equation space by 'cr_bs'.
290      */
291     ierr = PetscMalloc1(ncrs*node_data_sz, &tidx);CHKERRQ(ierr);
292     ierr = ISGetIndices(is_eq_num_prim, &idx);CHKERRQ(ierr);
293     for (ii=0,jj=0; ii<ncrs; ii++) {
294       PetscInt id = idx[ii*cr_bs]/cr_bs; /* get node back */
295       for (kk=0; kk<node_data_sz; kk++, jj++) tidx[jj] = id*node_data_sz + kk;
296     }
297     ierr = ISRestoreIndices(is_eq_num_prim, &idx);CHKERRQ(ierr);
298     ierr = ISCreateGeneral(comm, node_data_sz*ncrs, tidx, PETSC_COPY_VALUES, &isscat);CHKERRQ(ierr);
299     ierr = PetscFree(tidx);CHKERRQ(ierr);
300     /*
301      Create a vector to contain the original vertex information for each element
302      */
303     ierr = VecCreateSeq(PETSC_COMM_SELF, node_data_sz*ncrs, &src_crd);CHKERRQ(ierr);
304     for (jj=0; jj<ndata_cols; jj++) {
305       const PetscInt stride0=ncrs*pc_gamg->data_cell_rows;
306       for (ii=0; ii<ncrs; ii++) {
307         for (kk=0; kk<ndata_rows; kk++) {
308           PetscInt    ix = ii*ndata_rows + kk + jj*stride0, jx = ii*node_data_sz + kk*ndata_cols + jj;
309           PetscScalar tt = (PetscScalar)pc_gamg->data[ix];
310           ierr = VecSetValues(src_crd, 1, &jx, &tt, INSERT_VALUES);CHKERRQ(ierr);
311         }
312       }
313     }
314     ierr = VecAssemblyBegin(src_crd);CHKERRQ(ierr);
315     ierr = VecAssemblyEnd(src_crd);CHKERRQ(ierr);
316     /*
317       Scatter the element vertex information (still in the original vertex ordering)
318       to the correct processor
319     */
320     ierr = VecScatterCreate(src_crd, NULL, dest_crd, isscat, &vecscat);CHKERRQ(ierr);
321     ierr = ISDestroy(&isscat);CHKERRQ(ierr);
322     ierr = VecScatterBegin(vecscat,src_crd,dest_crd,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
323     ierr = VecScatterEnd(vecscat,src_crd,dest_crd,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
324     ierr = VecScatterDestroy(&vecscat);CHKERRQ(ierr);
325     ierr = VecDestroy(&src_crd);CHKERRQ(ierr);
326     /*
327       Put the element vertex data into a new allocation of the gdata->ele
328     */
329     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
330     ierr = PetscMalloc1(node_data_sz*ncrs_new, &pc_gamg->data);CHKERRQ(ierr);
331 
332     pc_gamg->data_sz = node_data_sz*ncrs_new;
333     strideNew        = ncrs_new*ndata_rows;
334 
335     ierr = VecGetArray(dest_crd, &array);CHKERRQ(ierr);
336     for (jj=0; jj<ndata_cols; jj++) {
337       for (ii=0; ii<ncrs_new; ii++) {
338         for (kk=0; kk<ndata_rows; kk++) {
339           PetscInt ix = ii*ndata_rows + kk + jj*strideNew, jx = ii*node_data_sz + kk*ndata_cols + jj;
340           pc_gamg->data[ix] = PetscRealPart(array[jx]);
341         }
342       }
343     }
344     ierr = VecRestoreArray(dest_crd, &array);CHKERRQ(ierr);
345     ierr = VecDestroy(&dest_crd);CHKERRQ(ierr);
346     }
347     /* move A and P (columns) with new layout */
348 #if defined PETSC_GAMG_USE_LOG
349     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET13],0,0,0,0);CHKERRQ(ierr);
350 #endif
351 
352     /*
353       Invert for MatGetSubMatrix
354     */
355     ierr = ISInvertPermutation(is_eq_num, ncrs_eq_new, &new_eq_indices);CHKERRQ(ierr);
356     ierr = ISSort(new_eq_indices);CHKERRQ(ierr); /* is this needed? */
357     ierr = ISSetBlockSize(new_eq_indices, cr_bs);CHKERRQ(ierr);
358     if (is_eq_num != is_eq_num_prim) {
359       ierr = ISDestroy(&is_eq_num_prim);CHKERRQ(ierr); /* could be same as 'is_eq_num' */
360     }
361     if (Pcolumnperm) {
362       ierr = PetscObjectReference((PetscObject)new_eq_indices);CHKERRQ(ierr);
363       *Pcolumnperm = new_eq_indices;
364     }
365     ierr = ISDestroy(&is_eq_num);CHKERRQ(ierr);
366 #if defined PETSC_GAMG_USE_LOG
367     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET13],0,0,0,0);CHKERRQ(ierr);
368     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET14],0,0,0,0);CHKERRQ(ierr);
369 #endif
370     /* 'a_Amat_crs' output */
371     {
372       Mat mat;
373       ierr        = MatGetSubMatrix(Cmat, new_eq_indices, new_eq_indices, MAT_INITIAL_MATRIX, &mat);CHKERRQ(ierr);
374       *a_Amat_crs = mat;
375 
376       if (!PETSC_TRUE) {
377         PetscInt cbs, rbs;
378         ierr = MatGetBlockSizes(Cmat, &rbs, &cbs);CHKERRQ(ierr);
379         ierr = PetscPrintf(MPI_COMM_SELF,"[%d]%s Old Mat rbs=%d cbs=%d\n",rank,__FUNCT__,rbs,cbs);CHKERRQ(ierr);
380         ierr = MatGetBlockSizes(mat, &rbs, &cbs);CHKERRQ(ierr);
381         ierr = PetscPrintf(MPI_COMM_SELF,"[%d]%s New Mat rbs=%d cbs=%d cr_bs=%d\n",rank,__FUNCT__,rbs,cbs,cr_bs);CHKERRQ(ierr);
382       }
383     }
384     ierr = MatDestroy(&Cmat);CHKERRQ(ierr);
385 
386 #if defined PETSC_GAMG_USE_LOG
387     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET14],0,0,0,0);CHKERRQ(ierr);
388 #endif
389     /* prolongator */
390     {
391       IS       findices;
392       PetscInt Istart,Iend;
393       Mat      Pnew;
394       ierr = MatGetOwnershipRange(Pold, &Istart, &Iend);CHKERRQ(ierr);
395 #if defined PETSC_GAMG_USE_LOG
396       ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET15],0,0,0,0);CHKERRQ(ierr);
397 #endif
398       ierr = ISCreateStride(comm,Iend-Istart,Istart,1,&findices);CHKERRQ(ierr);
399       ierr = ISSetBlockSize(findices,f_bs);CHKERRQ(ierr);
400       ierr = MatGetSubMatrix(Pold, findices, new_eq_indices, MAT_INITIAL_MATRIX, &Pnew);CHKERRQ(ierr);
401       ierr = ISDestroy(&findices);CHKERRQ(ierr);
402 
403       if (!PETSC_TRUE) {
404         PetscInt cbs, rbs;
405         ierr = MatGetBlockSizes(Pold, &rbs, &cbs);CHKERRQ(ierr);
406         ierr = PetscPrintf(MPI_COMM_SELF,"[%d]%s Pold rbs=%d cbs=%d\n",rank,__FUNCT__,rbs,cbs);CHKERRQ(ierr);
407         ierr = MatGetBlockSizes(Pnew, &rbs, &cbs);CHKERRQ(ierr);
408         ierr = PetscPrintf(MPI_COMM_SELF,"[%d]%s Pnew rbs=%d cbs=%d\n",rank,__FUNCT__,rbs,cbs);CHKERRQ(ierr);
409       }
410 #if defined PETSC_GAMG_USE_LOG
411       ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET15],0,0,0,0);CHKERRQ(ierr);
412 #endif
413       ierr = MatDestroy(a_P_inout);CHKERRQ(ierr);
414 
415       /* output - repartitioned */
416       *a_P_inout = Pnew;
417     }
418     ierr = ISDestroy(&new_eq_indices);CHKERRQ(ierr);
419 
420     *a_nactive_proc = new_size; /* output */
421   }
422 
423   /* outout matrix data */
424   if (!PETSC_TRUE) {
425     PetscViewer viewer; char fname[32]; static int llev=0; Cmat = *a_Amat_crs;
426     if (!llev) {
427       sprintf(fname,"Cmat_%d.m",llev++);
428       PetscViewerASCIIOpen(comm,fname,&viewer);
429       ierr = PetscViewerSetFormat(viewer, PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
430       ierr = MatView(Amat_fine, viewer);CHKERRQ(ierr);
431       ierr = PetscViewerDestroy(&viewer);
432     }
433     sprintf(fname,"Cmat_%d.m",llev++);
434     PetscViewerASCIIOpen(comm,fname,&viewer);
435     ierr = PetscViewerSetFormat(viewer, PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr);
436     ierr = MatView(Cmat, viewer);CHKERRQ(ierr);
437     ierr = PetscViewerDestroy(&viewer);
438   }
439   PetscFunctionReturn(0);
440 }
441 
442 /* -------------------------------------------------------------------------- */
443 /*
444    PCSetUp_GAMG - Prepares for the use of the GAMG preconditioner
445                     by setting data structures and options.
446 
447    Input Parameter:
448 .  pc - the preconditioner context
449 
450 */
451 #undef __FUNCT__
452 #define __FUNCT__ "PCSetUp_GAMG"
453 PetscErrorCode PCSetUp_GAMG(PC pc)
454 {
455   PetscErrorCode ierr;
456   PC_MG          *mg      = (PC_MG*)pc->data;
457   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
458   Mat            Pmat     = pc->pmat;
459   PetscInt       fine_level,level,level1,bs,M,qq,lidx,nASMBlocksArr[GAMG_MAXLEVELS];
460   MPI_Comm       comm;
461   PetscMPIInt    rank,size,nactivepe;
462   Mat            Aarr[GAMG_MAXLEVELS],Parr[GAMG_MAXLEVELS];
463   IS             *ASMLocalIDsArr[GAMG_MAXLEVELS];
464   PetscLogDouble nnz0=0.,nnztot=0.;
465   MatInfo        info;
466 
467   PetscFunctionBegin;
468   ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
469   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
470   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
471 
472   if (pc_gamg->setup_count++ > 0) {
473     if ((PetscBool)(!pc_gamg->reuse_prol)) {
474       /* reset everything */
475       ierr = PCReset_MG(pc);CHKERRQ(ierr);
476       pc->setupcalled = 0;
477     } else {
478       PC_MG_Levels **mglevels = mg->levels;
479       /* just do Galerkin grids */
480       Mat          B,dA,dB;
481 
482      if (!pc->setupcalled) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"PCSetUp() has not been called yet");
483       if (pc_gamg->Nlevels > 1) {
484         /* currently only handle case where mat and pmat are the same on coarser levels */
485         ierr = KSPGetOperators(mglevels[pc_gamg->Nlevels-1]->smoothd,&dA,&dB);CHKERRQ(ierr);
486         /* (re)set to get dirty flag */
487         ierr = KSPSetOperators(mglevels[pc_gamg->Nlevels-1]->smoothd,dA,dB);CHKERRQ(ierr);
488 
489         for (level=pc_gamg->Nlevels-2; level>=0; level--) {
490           /* the first time through the matrix structure has changed from repartitioning */
491           if (pc_gamg->setup_count==2) {
492             ierr = MatPtAP(dB,mglevels[level+1]->interpolate,MAT_INITIAL_MATRIX,1.0,&B);CHKERRQ(ierr);
493             ierr = MatDestroy(&mglevels[level]->A);CHKERRQ(ierr);
494 
495             mglevels[level]->A = B;
496           } else {
497             ierr = KSPGetOperators(mglevels[level]->smoothd,NULL,&B);CHKERRQ(ierr);
498             ierr = MatPtAP(dB,mglevels[level+1]->interpolate,MAT_REUSE_MATRIX,1.0,&B);CHKERRQ(ierr);
499           }
500           ierr = KSPSetOperators(mglevels[level]->smoothd,B,B);CHKERRQ(ierr);
501           dB   = B;
502         }
503       }
504 
505       ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
506 
507       PetscFunctionReturn(0);
508     }
509   }
510 
511   if (!pc_gamg->data) {
512     if (pc_gamg->orig_data) {
513       ierr = MatGetBlockSize(Pmat, &bs);CHKERRQ(ierr);
514       ierr = MatGetLocalSize(Pmat, &qq, NULL);CHKERRQ(ierr);
515 
516       pc_gamg->data_sz        = (qq/bs)*pc_gamg->orig_data_cell_rows*pc_gamg->orig_data_cell_cols;
517       pc_gamg->data_cell_rows = pc_gamg->orig_data_cell_rows;
518       pc_gamg->data_cell_cols = pc_gamg->orig_data_cell_cols;
519 
520       ierr = PetscMalloc1(pc_gamg->data_sz, &pc_gamg->data);CHKERRQ(ierr);
521       for (qq=0; qq<pc_gamg->data_sz; qq++) pc_gamg->data[qq] = pc_gamg->orig_data[qq];
522     } else {
523       if (!pc_gamg->ops->createdefaultdata) SETERRQ(comm,PETSC_ERR_PLIB,"'createdefaultdata' not set(?) need to support NULL data");
524       ierr = pc_gamg->ops->createdefaultdata(pc,Pmat);CHKERRQ(ierr);
525     }
526   }
527 
528   /* cache original data for reuse */
529   if (!pc_gamg->orig_data && (PetscBool)(!pc_gamg->reuse_prol)) {
530     ierr = PetscMalloc1(pc_gamg->data_sz, &pc_gamg->orig_data);CHKERRQ(ierr);
531     for (qq=0; qq<pc_gamg->data_sz; qq++) pc_gamg->orig_data[qq] = pc_gamg->data[qq];
532     pc_gamg->orig_data_cell_rows = pc_gamg->data_cell_rows;
533     pc_gamg->orig_data_cell_cols = pc_gamg->data_cell_cols;
534   }
535 
536   /* get basic dims */
537   ierr = MatGetBlockSize(Pmat, &bs);CHKERRQ(ierr);
538   ierr = MatGetSize(Pmat, &M, &qq);CHKERRQ(ierr);
539 
540   ierr = MatGetInfo(Pmat,MAT_GLOBAL_SUM,&info);CHKERRQ(ierr); /* global reduction */
541   nnz0   = info.nz_used;
542   nnztot = info.nz_used;
543   ierr = PetscInfo6(pc,"level %d) N=%D, n data rows=%d, n data cols=%d, nnz/row (ave)=%d, np=%d\n",
544                     0,M,pc_gamg->data_cell_rows,pc_gamg->data_cell_cols,
545                     (int)(nnz0/(PetscReal)M+0.5),size);
546   CHKERRQ(ierr);
547 
548   /* Get A_i and R_i */
549   for (level=0, Aarr[0]=Pmat, nactivepe = size; /* hard wired stopping logic */
550        level < (pc_gamg->Nlevels-1) && (!level || M>pc_gamg->coarse_eq_limit);
551        level++) {
552     pc_gamg->current_level = level;
553     level1 = level + 1;
554 #if defined PETSC_GAMG_USE_LOG
555     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET1],0,0,0,0);CHKERRQ(ierr);
556 #if (defined GAMG_STAGES)
557     ierr = PetscLogStagePush(gamg_stages[level]);CHKERRQ(ierr);
558 #endif
559 #endif
560     { /* construct prolongator */
561       Mat              Gmat;
562       PetscCoarsenData *agg_lists;
563       Mat              Prol11;
564 
565       ierr = pc_gamg->ops->graph(pc,Aarr[level], &Gmat);CHKERRQ(ierr);
566       ierr = pc_gamg->ops->coarsen(pc, &Gmat, &agg_lists);CHKERRQ(ierr);
567       ierr = pc_gamg->ops->prolongator(pc,Aarr[level],Gmat,agg_lists,&Prol11);CHKERRQ(ierr);
568 
569       /* could have failed to create new level */
570       if (Prol11) {
571         /* get new block size of coarse matrices */
572         ierr = MatGetBlockSizes(Prol11, NULL, &bs);CHKERRQ(ierr);
573 
574         if (pc_gamg->ops->optprolongator) {
575           /* smooth */
576           ierr = pc_gamg->ops->optprolongator(pc, Aarr[level], &Prol11);CHKERRQ(ierr);
577         }
578 
579         Parr[level1] = Prol11;
580       } else Parr[level1] = NULL;
581 
582       if (pc_gamg->use_aggs_in_gasm) {
583         PetscInt bs;
584         ierr = MatGetBlockSizes(Prol11, &bs, NULL);CHKERRQ(ierr);
585         ierr = PetscCDGetASMBlocks(agg_lists, bs, &nASMBlocksArr[level], &ASMLocalIDsArr[level]);CHKERRQ(ierr);
586       }
587 
588       ierr = MatDestroy(&Gmat);CHKERRQ(ierr);
589       ierr = PetscCDDestroy(agg_lists);CHKERRQ(ierr);
590     } /* construct prolongator scope */
591 #if defined PETSC_GAMG_USE_LOG
592     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET1],0,0,0,0);CHKERRQ(ierr);
593 #endif
594     if (!level) Aarr[0] = Pmat; /* use Pmat for finest level setup */
595     if (!Parr[level1]) {
596       ierr =  PetscInfo1(pc,"Stop gridding, level %D\n",level);CHKERRQ(ierr);
597 #if (defined PETSC_GAMG_USE_LOG && defined GAMG_STAGES)
598       ierr = PetscLogStagePop();CHKERRQ(ierr);
599 #endif
600       break;
601     }
602 #if defined PETSC_GAMG_USE_LOG
603     ierr = PetscLogEventBegin(petsc_gamg_setup_events[SET2],0,0,0,0);CHKERRQ(ierr);
604 #endif
605 
606     ierr = pc_gamg->ops->createlevel(pc, Aarr[level], bs,&Parr[level1], &Aarr[level1], &nactivepe, NULL);CHKERRQ(ierr);
607 
608 #if defined PETSC_GAMG_USE_LOG
609     ierr = PetscLogEventEnd(petsc_gamg_setup_events[SET2],0,0,0,0);CHKERRQ(ierr);
610 #endif
611     ierr = MatGetSize(Aarr[level1], &M, &qq);CHKERRQ(ierr);
612 
613     ierr = MatGetInfo(Aarr[level1], MAT_GLOBAL_SUM, &info);CHKERRQ(ierr);
614     nnztot += info.nz_used;
615     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);
616 
617 #if (defined PETSC_GAMG_USE_LOG && defined GAMG_STAGES)
618     ierr = PetscLogStagePop();CHKERRQ(ierr);
619 #endif
620     /* stop if one node or one proc -- could pull back for singular problems */
621     if ( (pc_gamg->data_cell_cols && M/pc_gamg->data_cell_cols < 2) || (!pc_gamg->data_cell_cols && M/bs < 2) ) {
622       ierr =  PetscInfo2(pc,"HARD stop of coarsening on level %D.  Grid too small: %D block nodes\n",level,M/bs);CHKERRQ(ierr);
623       level++;
624       break;
625     }
626   } /* levels */
627   ierr                  = PetscFree(pc_gamg->data);CHKERRQ(ierr);
628 
629   ierr = PetscInfo2(pc,"%D levels, grid complexity = %g\n",level+1,nnztot/nnz0);CHKERRQ(ierr);
630   pc_gamg->Nlevels = level + 1;
631   fine_level       = level;
632   ierr             = PCMGSetLevels(pc,pc_gamg->Nlevels,NULL);CHKERRQ(ierr);
633 
634   /* simple setup */
635   if (!PETSC_TRUE) {
636     PC_MG_Levels **mglevels = mg->levels;
637     for (lidx=0,level=pc_gamg->Nlevels-1;
638          lidx<fine_level;
639          lidx++, level--) {
640       ierr = PCMGSetInterpolation(pc, lidx+1, Parr[level]);CHKERRQ(ierr);
641       ierr = KSPSetOperators(mglevels[lidx]->smoothd, Aarr[level], Aarr[level]);CHKERRQ(ierr);
642       ierr = MatDestroy(&Parr[level]);CHKERRQ(ierr);
643       ierr = MatDestroy(&Aarr[level]);CHKERRQ(ierr);
644     }
645     ierr = KSPSetOperators(mglevels[fine_level]->smoothd, Aarr[0], Aarr[0]);CHKERRQ(ierr);
646 
647     ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
648   } else if (pc_gamg->Nlevels > 1) { /* don't setup MG if one level */
649     /* set default smoothers & set operators */
650     for (lidx = 1, level = pc_gamg->Nlevels-2;
651          lidx <= fine_level;
652          lidx++, level--) {
653       KSP smoother;
654       PC  subpc;
655 
656       ierr = PCMGGetSmoother(pc, lidx, &smoother);CHKERRQ(ierr);
657       ierr = KSPGetPC(smoother, &subpc);CHKERRQ(ierr);
658 
659       ierr = KSPSetNormType(smoother, KSP_NORM_NONE);CHKERRQ(ierr);
660       /* set ops */
661       ierr = KSPSetOperators(smoother, Aarr[level], Aarr[level]);CHKERRQ(ierr);
662       ierr = PCMGSetInterpolation(pc, lidx, Parr[level+1]);CHKERRQ(ierr);
663 
664       /* set defaults */
665       ierr = KSPSetType(smoother, KSPCHEBYSHEV);CHKERRQ(ierr);
666 
667       /* set blocks for GASM smoother that uses the 'aggregates' */
668       if (pc_gamg->use_aggs_in_gasm) {
669         PetscInt sz;
670         IS       *is;
671 
672         sz   = nASMBlocksArr[level];
673         is   = ASMLocalIDsArr[level];
674         ierr = PCSetType(subpc, PCGASM);CHKERRQ(ierr);
675         ierr = PCGASMSetOverlap(subpc, 0);CHKERRQ(ierr);
676         if (!sz) {
677           IS       is;
678           PetscInt my0,kk;
679           ierr = MatGetOwnershipRange(Aarr[level], &my0, &kk);CHKERRQ(ierr);
680           ierr = ISCreateGeneral(PETSC_COMM_SELF, 1, &my0, PETSC_COPY_VALUES, &is);CHKERRQ(ierr);
681           ierr = PCGASMSetSubdomains(subpc, 1, &is, NULL);CHKERRQ(ierr);
682           ierr = ISDestroy(&is);CHKERRQ(ierr);
683         } else {
684           PetscInt kk;
685           ierr = PCGASMSetSubdomains(subpc, sz, is, NULL);CHKERRQ(ierr);
686           for (kk=0; kk<sz; kk++) {
687             ierr = ISDestroy(&is[kk]);CHKERRQ(ierr);
688           }
689           ierr = PetscFree(is);CHKERRQ(ierr);
690         }
691         ASMLocalIDsArr[level] = NULL;
692         nASMBlocksArr[level]  = 0;
693         ierr                  = PCGASMSetType(subpc, PC_GASM_BASIC);CHKERRQ(ierr);
694       } else {
695         ierr = PCSetType(subpc, PCSOR);CHKERRQ(ierr);
696       }
697     }
698     {
699       /* coarse grid */
700       KSP smoother,*k2; PC subpc,pc2; PetscInt ii,first;
701       Mat Lmat = Aarr[(level=pc_gamg->Nlevels-1)]; lidx = 0;
702       ierr = PCMGGetSmoother(pc, lidx, &smoother);CHKERRQ(ierr);
703       ierr = KSPSetOperators(smoother, Lmat, Lmat);CHKERRQ(ierr);
704       ierr = KSPSetNormType(smoother, KSP_NORM_NONE);CHKERRQ(ierr);
705       ierr = KSPGetPC(smoother, &subpc);CHKERRQ(ierr);
706       ierr = PCSetType(subpc, PCBJACOBI);CHKERRQ(ierr);
707       ierr = PCSetUp(subpc);CHKERRQ(ierr);
708       ierr = PCBJacobiGetSubKSP(subpc,&ii,&first,&k2);CHKERRQ(ierr);
709       if (ii != 1) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"ii %D is not one",ii);
710       ierr = KSPGetPC(k2[0],&pc2);CHKERRQ(ierr);
711       ierr = PCSetType(pc2, PCLU);CHKERRQ(ierr);
712       ierr = PCFactorSetShiftType(pc2,MAT_SHIFT_INBLOCKS);CHKERRQ(ierr);
713       ierr = KSPSetTolerances(k2[0],PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,1);CHKERRQ(ierr);
714       ierr = KSPSetType(k2[0], KSPPREONLY);CHKERRQ(ierr);
715       /* This flag gets reset by PCBJacobiGetSubKSP(), but our BJacobi really does the same algorithm everywhere (and in
716        * fact, all but one process will have zero dofs), so we reset the flag to avoid having PCView_BJacobi attempt to
717        * view every subdomain as though they were different. */
718       ((PC_BJacobi*)subpc->data)->same_local_solves = PETSC_TRUE;
719     }
720 
721     /* should be called in PCSetFromOptions_GAMG(), but cannot be called prior to PCMGSetLevels() */
722     ierr = PetscObjectOptionsBegin((PetscObject)pc);CHKERRQ(ierr);
723     ierr = PCSetFromOptions_MG(PetscOptionsObject,pc);CHKERRQ(ierr);
724     ierr = PetscOptionsEnd();CHKERRQ(ierr);
725     if (!mg->galerkin) SETERRQ(comm,PETSC_ERR_USER,"PCGAMG must use Galerkin for coarse operators.");
726     if (mg->galerkin == 1) mg->galerkin = 2;
727 
728     /* clean up */
729     for (level=1; level<pc_gamg->Nlevels; level++) {
730       ierr = MatDestroy(&Parr[level]);CHKERRQ(ierr);
731       ierr = MatDestroy(&Aarr[level]);CHKERRQ(ierr);
732     }
733 
734     ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
735   } else {
736     KSP smoother;
737     ierr = PetscInfo(pc,"One level solver used (system is seen as DD). Using default solver.\n");CHKERRQ(ierr);
738     ierr = PCMGGetSmoother(pc, 0, &smoother);CHKERRQ(ierr);
739     ierr = KSPSetOperators(smoother, Aarr[0], Aarr[0]);CHKERRQ(ierr);
740     ierr = KSPSetType(smoother, KSPPREONLY);CHKERRQ(ierr);
741     ierr = PCSetUp_MG(pc);CHKERRQ(ierr);
742   }
743   PetscFunctionReturn(0);
744 }
745 
746 /* ------------------------------------------------------------------------- */
747 /*
748  PCDestroy_GAMG - Destroys the private context for the GAMG preconditioner
749    that was created with PCCreate_GAMG().
750 
751    Input Parameter:
752 .  pc - the preconditioner context
753 
754    Application Interface Routine: PCDestroy()
755 */
756 #undef __FUNCT__
757 #define __FUNCT__ "PCDestroy_GAMG"
758 PetscErrorCode PCDestroy_GAMG(PC pc)
759 {
760   PetscErrorCode ierr;
761   PC_MG          *mg     = (PC_MG*)pc->data;
762   PC_GAMG        *pc_gamg= (PC_GAMG*)mg->innerctx;
763 
764   PetscFunctionBegin;
765   ierr = PCReset_GAMG(pc);CHKERRQ(ierr);
766   if (pc_gamg->ops->destroy) {
767     ierr = (*pc_gamg->ops->destroy)(pc);CHKERRQ(ierr);
768   }
769   ierr = PetscFree(pc_gamg->ops);CHKERRQ(ierr);
770   ierr = PetscFree(pc_gamg->gamg_type_name);CHKERRQ(ierr);
771   ierr = PetscFree(pc_gamg);CHKERRQ(ierr);
772   ierr = PCDestroy_MG(pc);CHKERRQ(ierr);
773   PetscFunctionReturn(0);
774 }
775 
776 
777 #undef __FUNCT__
778 #define __FUNCT__ "PCGAMGSetProcEqLim"
779 /*@
780    PCGAMGSetProcEqLim - Set number of equations to aim for on coarse grids via processor reduction.
781 
782    Logically Collective on PC
783 
784    Input Parameters:
785 +  pc - the preconditioner context
786 -  n - the number of equations
787 
788 
789    Options Database Key:
790 .  -pc_gamg_process_eq_limit <limit>
791 
792    Level: intermediate
793 
794    Concepts: Unstructured multigrid preconditioner
795 
796 .seealso: PCGAMGSetCoarseEqLim()
797 @*/
798 PetscErrorCode  PCGAMGSetProcEqLim(PC pc, PetscInt n)
799 {
800   PetscErrorCode ierr;
801 
802   PetscFunctionBegin;
803   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
804   ierr = PetscTryMethod(pc,"PCGAMGSetProcEqLim_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
805   PetscFunctionReturn(0);
806 }
807 
808 #undef __FUNCT__
809 #define __FUNCT__ "PCGAMGSetProcEqLim_GAMG"
810 static PetscErrorCode PCGAMGSetProcEqLim_GAMG(PC pc, PetscInt n)
811 {
812   PC_MG   *mg      = (PC_MG*)pc->data;
813   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
814 
815   PetscFunctionBegin;
816   if (n>0) pc_gamg->min_eq_proc = n;
817   PetscFunctionReturn(0);
818 }
819 
820 #undef __FUNCT__
821 #define __FUNCT__ "PCGAMGSetCoarseEqLim"
822 /*@
823    PCGAMGSetCoarseEqLim - Set max number of equations on coarse grids.
824 
825  Collective on PC
826 
827    Input Parameters:
828 +  pc - the preconditioner context
829 -  n - maximum number of equations to aim for
830 
831    Options Database Key:
832 .  -pc_gamg_coarse_eq_limit <limit>
833 
834    Level: intermediate
835 
836    Concepts: Unstructured multigrid preconditioner
837 
838 .seealso: PCGAMGSetProcEqLim()
839 @*/
840 PetscErrorCode PCGAMGSetCoarseEqLim(PC pc, PetscInt n)
841 {
842   PetscErrorCode ierr;
843 
844   PetscFunctionBegin;
845   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
846   ierr = PetscTryMethod(pc,"PCGAMGSetCoarseEqLim_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
847   PetscFunctionReturn(0);
848 }
849 
850 #undef __FUNCT__
851 #define __FUNCT__ "PCGAMGSetCoarseEqLim_GAMG"
852 static PetscErrorCode PCGAMGSetCoarseEqLim_GAMG(PC pc, PetscInt n)
853 {
854   PC_MG   *mg      = (PC_MG*)pc->data;
855   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
856 
857   PetscFunctionBegin;
858   if (n>0) pc_gamg->coarse_eq_limit = n;
859   PetscFunctionReturn(0);
860 }
861 
862 #undef __FUNCT__
863 #define __FUNCT__ "PCGAMGSetRepartitioning"
864 /*@
865    PCGAMGSetRepartitioning - Repartition the coarse grids
866 
867    Collective on PC
868 
869    Input Parameters:
870 +  pc - the preconditioner context
871 -  n - PETSC_TRUE or PETSC_FALSE
872 
873    Options Database Key:
874 .  -pc_gamg_repartition <true,false>
875 
876    Level: intermediate
877 
878    Concepts: Unstructured multigrid preconditioner
879 
880 .seealso: ()
881 @*/
882 PetscErrorCode PCGAMGSetRepartitioning(PC pc, PetscBool n)
883 {
884   PetscErrorCode ierr;
885 
886   PetscFunctionBegin;
887   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
888   ierr = PetscTryMethod(pc,"PCGAMGSetRepartitioning_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
889   PetscFunctionReturn(0);
890 }
891 
892 #undef __FUNCT__
893 #define __FUNCT__ "PCGAMGSetRepartitioning_GAMG"
894 static PetscErrorCode PCGAMGSetRepartitioning_GAMG(PC pc, PetscBool n)
895 {
896   PC_MG   *mg      = (PC_MG*)pc->data;
897   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
898 
899   PetscFunctionBegin;
900   pc_gamg->repart = n;
901   PetscFunctionReturn(0);
902 }
903 
904 #undef __FUNCT__
905 #define __FUNCT__ "PCGAMGSetReuseInterpolation"
906 /*@
907    PCGAMGSetReuseInterpolation - Reuse prolongation when rebuilding preconditioner
908 
909    Collective on PC
910 
911    Input Parameters:
912 +  pc - the preconditioner context
913 -  n - PETSC_TRUE or PETSC_FALSE
914 
915    Options Database Key:
916 .  -pc_gamg_reuse_interpolation <true,false>
917 
918    Level: intermediate
919 
920    Concepts: Unstructured multigrid preconditioner
921 
922 .seealso: ()
923 @*/
924 PetscErrorCode PCGAMGSetReuseInterpolation(PC pc, PetscBool n)
925 {
926   PetscErrorCode ierr;
927 
928   PetscFunctionBegin;
929   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
930   ierr = PetscTryMethod(pc,"PCGAMGSetReuseInterpolation_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
931   PetscFunctionReturn(0);
932 }
933 
934 #undef __FUNCT__
935 #define __FUNCT__ "PCGAMGSetReuseInterpolation_GAMG"
936 static PetscErrorCode PCGAMGSetReuseInterpolation_GAMG(PC pc, PetscBool n)
937 {
938   PC_MG   *mg      = (PC_MG*)pc->data;
939   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
940 
941   PetscFunctionBegin;
942   pc_gamg->reuse_prol = n;
943   PetscFunctionReturn(0);
944 }
945 
946 #undef __FUNCT__
947 #define __FUNCT__ "PCGAMGSetUseASMAggs"
948 /*@
949    PCGAMGSetUseASMAggs -
950 
951    Collective on PC
952 
953    Input Parameters:
954 .  pc - the preconditioner context
955 
956 
957    Options Database Key:
958 .  -pc_gamg_use_agg_gasm
959 
960    Level: intermediate
961 
962    Concepts: Unstructured multigrid preconditioner
963 
964 .seealso: ()
965 @*/
966 PetscErrorCode PCGAMGSetUseASMAggs(PC pc, PetscBool n)
967 {
968   PetscErrorCode ierr;
969 
970   PetscFunctionBegin;
971   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
972   ierr = PetscTryMethod(pc,"PCGAMGSetUseASMAggs_C",(PC,PetscBool),(pc,n));CHKERRQ(ierr);
973   PetscFunctionReturn(0);
974 }
975 
976 #undef __FUNCT__
977 #define __FUNCT__ "PCGAMGSetUseASMAggs_GAMG"
978 static PetscErrorCode PCGAMGSetUseASMAggs_GAMG(PC pc, PetscBool n)
979 {
980   PC_MG   *mg      = (PC_MG*)pc->data;
981   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
982 
983   PetscFunctionBegin;
984   pc_gamg->use_aggs_in_gasm = n;
985   PetscFunctionReturn(0);
986 }
987 
988 #undef __FUNCT__
989 #define __FUNCT__ "PCGAMGSetNlevels"
990 /*@
991    PCGAMGSetNlevels -  Sets the maximum number of levels PCGAMG will use
992 
993    Not collective on PC
994 
995    Input Parameters:
996 +  pc - the preconditioner
997 -  n - the maximum number of levels to use
998 
999    Options Database Key:
1000 .  -pc_mg_levels
1001 
1002    Level: intermediate
1003 
1004    Concepts: Unstructured multigrid preconditioner
1005 
1006 .seealso: ()
1007 @*/
1008 PetscErrorCode PCGAMGSetNlevels(PC pc, PetscInt n)
1009 {
1010   PetscErrorCode ierr;
1011 
1012   PetscFunctionBegin;
1013   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
1014   ierr = PetscTryMethod(pc,"PCGAMGSetNlevels_C",(PC,PetscInt),(pc,n));CHKERRQ(ierr);
1015   PetscFunctionReturn(0);
1016 }
1017 
1018 #undef __FUNCT__
1019 #define __FUNCT__ "PCGAMGSetNlevels_GAMG"
1020 static PetscErrorCode PCGAMGSetNlevels_GAMG(PC pc, PetscInt n)
1021 {
1022   PC_MG   *mg      = (PC_MG*)pc->data;
1023   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
1024 
1025   PetscFunctionBegin;
1026   pc_gamg->Nlevels = n;
1027   PetscFunctionReturn(0);
1028 }
1029 
1030 #undef __FUNCT__
1031 #define __FUNCT__ "PCGAMGSetThreshold"
1032 /*@
1033    PCGAMGSetThreshold - Relative threshold to use for dropping edges in aggregation graph
1034 
1035    Not collective on PC
1036 
1037    Input Parameters:
1038 +  pc - the preconditioner context
1039 -  threshold - the threshold value, 0.0 means keep all nonzero entries in the graph; negative means keep even zero entries in the graph
1040 
1041    Options Database Key:
1042 .  -pc_gamg_threshold <threshold>
1043 
1044    Level: intermediate
1045 
1046    Concepts: Unstructured multigrid preconditioner
1047 
1048 .seealso: ()
1049 @*/
1050 PetscErrorCode PCGAMGSetThreshold(PC pc, PetscReal n)
1051 {
1052   PetscErrorCode ierr;
1053 
1054   PetscFunctionBegin;
1055   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
1056   ierr = PetscTryMethod(pc,"PCGAMGSetThreshold_C",(PC,PetscReal),(pc,n));CHKERRQ(ierr);
1057   PetscFunctionReturn(0);
1058 }
1059 
1060 #undef __FUNCT__
1061 #define __FUNCT__ "PCGAMGSetThreshold_GAMG"
1062 static PetscErrorCode PCGAMGSetThreshold_GAMG(PC pc, PetscReal n)
1063 {
1064   PC_MG   *mg      = (PC_MG*)pc->data;
1065   PC_GAMG *pc_gamg = (PC_GAMG*)mg->innerctx;
1066 
1067   PetscFunctionBegin;
1068   pc_gamg->threshold = n;
1069   PetscFunctionReturn(0);
1070 }
1071 
1072 #undef __FUNCT__
1073 #define __FUNCT__ "PCGAMGSetType"
1074 /*@
1075    PCGAMGSetType - Set solution method
1076 
1077    Collective on PC
1078 
1079    Input Parameters:
1080 +  pc - the preconditioner context
1081 -  type - PCGAMGAGG, PCGAMGGEO, or PCGAMGCLASSICAL
1082 
1083    Options Database Key:
1084 .  -pc_gamg_type <agg,geo,classical>
1085 
1086    Level: intermediate
1087 
1088    Concepts: Unstructured multigrid preconditioner
1089 
1090 .seealso: PCGAMGGetType(), PCGAMG
1091 @*/
1092 PetscErrorCode PCGAMGSetType(PC pc, PCGAMGType type)
1093 {
1094   PetscErrorCode ierr;
1095 
1096   PetscFunctionBegin;
1097   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
1098   ierr = PetscTryMethod(pc,"PCGAMGSetType_C",(PC,PCGAMGType),(pc,type));CHKERRQ(ierr);
1099   PetscFunctionReturn(0);
1100 }
1101 
1102 #undef __FUNCT__
1103 #define __FUNCT__ "PCGAMGGetType"
1104 /*@
1105    PCGAMGGetType - Get solution method
1106 
1107    Collective on PC
1108 
1109    Input Parameter:
1110 .  pc - the preconditioner context
1111 
1112    Output Parameter:
1113 .  type - the type of algorithm used
1114 
1115    Level: intermediate
1116 
1117    Concepts: Unstructured multigrid preconditioner
1118 
1119 .seealso: PCGAMGSetType(), PCGAMGType
1120 @*/
1121 PetscErrorCode PCGAMGGetType(PC pc, PCGAMGType *type)
1122 {
1123   PetscErrorCode ierr;
1124 
1125   PetscFunctionBegin;
1126   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
1127   ierr = PetscUseMethod(pc,"PCGAMGGetType_C",(PC,PCGAMGType*),(pc,type));CHKERRQ(ierr);
1128   PetscFunctionReturn(0);
1129 }
1130 
1131 #undef __FUNCT__
1132 #define __FUNCT__ "PCGAMGGetType_GAMG"
1133 static PetscErrorCode PCGAMGGetType_GAMG(PC pc, PCGAMGType *type)
1134 {
1135   PC_MG          *mg      = (PC_MG*)pc->data;
1136   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1137 
1138   PetscFunctionBegin;
1139   *type = pc_gamg->type;
1140   PetscFunctionReturn(0);
1141 }
1142 
1143 #undef __FUNCT__
1144 #define __FUNCT__ "PCGAMGSetType_GAMG"
1145 static PetscErrorCode PCGAMGSetType_GAMG(PC pc, PCGAMGType type)
1146 {
1147   PetscErrorCode ierr,(*r)(PC);
1148   PC_MG          *mg      = (PC_MG*)pc->data;
1149   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1150 
1151   PetscFunctionBegin;
1152   pc_gamg->type = type;
1153   ierr = PetscFunctionListFind(GAMGList,type,&r);CHKERRQ(ierr);
1154   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unknown GAMG type %s given",type);
1155   if (pc_gamg->ops->destroy) {
1156     ierr = (*pc_gamg->ops->destroy)(pc);CHKERRQ(ierr);
1157     ierr = PetscMemzero(pc_gamg->ops,sizeof(struct _PCGAMGOps));CHKERRQ(ierr);
1158     pc_gamg->ops->createlevel = PCGAMGCreateLevel_GAMG;
1159     /* cleaning up common data in pc_gamg - this should disapear someday */
1160     pc_gamg->data_cell_cols = 0;
1161     pc_gamg->data_cell_rows = 0;
1162     pc_gamg->orig_data_cell_cols = 0;
1163     pc_gamg->orig_data_cell_rows = 0;
1164     ierr = PetscFree(pc_gamg->data);CHKERRQ(ierr);
1165     pc_gamg->data_sz = 0;
1166   }
1167   ierr = PetscFree(pc_gamg->gamg_type_name);CHKERRQ(ierr);
1168   ierr = PetscStrallocpy(type,&pc_gamg->gamg_type_name);CHKERRQ(ierr);
1169   ierr = (*r)(pc);CHKERRQ(ierr);
1170   PetscFunctionReturn(0);
1171 }
1172 
1173 #undef __FUNCT__
1174 #define __FUNCT__ "PCView_GAMG"
1175 static PetscErrorCode PCView_GAMG(PC pc,PetscViewer viewer)
1176 {
1177   PetscErrorCode ierr;
1178   PC_MG          *mg      = (PC_MG*)pc->data;
1179   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1180 
1181   PetscFunctionBegin;
1182   ierr = PetscViewerASCIIPrintf(viewer,"    GAMG specific options\n");CHKERRQ(ierr);
1183   ierr = PetscViewerASCIIPrintf(viewer,"      Threshold for dropping small values from graph %g\n",(double)pc_gamg->threshold);CHKERRQ(ierr);
1184   if (pc_gamg->ops->view) {
1185     ierr = (*pc_gamg->ops->view)(pc,viewer);CHKERRQ(ierr);
1186   }
1187   PetscFunctionReturn(0);
1188 }
1189 
1190 #undef __FUNCT__
1191 #define __FUNCT__ "PCSetFromOptions_GAMG"
1192 PetscErrorCode PCSetFromOptions_GAMG(PetscOptions *PetscOptionsObject,PC pc)
1193 {
1194   PetscErrorCode ierr;
1195   PC_MG          *mg      = (PC_MG*)pc->data;
1196   PC_GAMG        *pc_gamg = (PC_GAMG*)mg->innerctx;
1197   PetscBool      flag;
1198   MPI_Comm       comm;
1199 
1200   PetscFunctionBegin;
1201   ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
1202   ierr = PetscOptionsHead(PetscOptionsObject,"GAMG options");CHKERRQ(ierr);
1203   {
1204     char tname[256];
1205     ierr = PetscOptionsFList("-pc_gamg_type","Type of AMG method","PCGAMGSetType",GAMGList, pc_gamg->gamg_type_name, tname, sizeof(tname), &flag);CHKERRQ(ierr);
1206     if (flag) {
1207       ierr = PCGAMGSetType(pc,tname);CHKERRQ(ierr);
1208     }
1209     ierr = PetscOptionsBool("-pc_gamg_repartition","Repartion coarse grids","PCGAMGRepartitioning",pc_gamg->repart,&pc_gamg->repart,NULL);CHKERRQ(ierr);
1210     ierr = PetscOptionsBool("-pc_gamg_reuse_interpolation","Reuse prolongation operator","PCGAMGReuseInterpolation",pc_gamg->reuse_prol,&pc_gamg->reuse_prol,NULL);CHKERRQ(ierr);
1211     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);
1212     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);
1213     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);
1214     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);
1215     ierr = PetscOptionsInt("-pc_mg_levels","Set number of MG levels","PCGAMGSetNlevels",pc_gamg->Nlevels,&pc_gamg->Nlevels,NULL);CHKERRQ(ierr);
1216 
1217     /* set options for subtype */
1218     if (pc_gamg->ops->setfromoptions) {ierr = (*pc_gamg->ops->setfromoptions)(PetscOptionsObject,pc);CHKERRQ(ierr);}
1219   }
1220   ierr = PetscOptionsTail();CHKERRQ(ierr);
1221   PetscFunctionReturn(0);
1222 }
1223 
1224 /* -------------------------------------------------------------------------- */
1225 /*MC
1226      PCGAMG - Geometric algebraic multigrid (AMG) preconditioner
1227 
1228    Options Database Keys:
1229    Multigrid options(inherited)
1230 +  -pc_mg_cycles <v>: v or w (PCMGSetCycleType())
1231 .  -pc_mg_smoothup <1>: Number of post-smoothing steps (PCMGSetNumberSmoothUp)
1232 .  -pc_mg_smoothdown <1>: Number of pre-smoothing steps (PCMGSetNumberSmoothDown)
1233 -  -pc_mg_type <multiplicative>: (one of) additive multiplicative full kascade
1234 
1235 
1236   Notes: In order to obtain good performance for PCGAMG for vector valued problems you must
1237 $       Call MatSetBlockSize() to indicate the number of degrees of freedom per grid point
1238 $       Call MatSetNearNullSpace() (or PCSetCoordinates() if solving the equations of elasticity) to indicate the near null space of the operator
1239 $       See the Users Manual Chapter 4 for more details
1240 
1241   Level: intermediate
1242 
1243   Concepts: algebraic multigrid
1244 
1245 .seealso:  PCCreate(), PCSetType(), MatSetBlockSize(), PCMGType, PCSetCoordinates(), MatSetNearNullSpace(), PCGAMGSetType(), PCGAMGAGG, PCGAMGGEO, PCGAMGCLASSICAL, PCGAMGSetProcEqLim(),
1246            PCGAMGSetCoarseEqLim(), PCGAMGSetRepartitioning(), PCGAMGRegister(), PCGAMGSetReuseInterpolation(), PCGAMGSetUseASMAggs(), PCGAMGSetNlevels(), PCGAMGSetThreshold(), PCGAMGGetType()
1247 M*/
1248 
1249 #undef __FUNCT__
1250 #define __FUNCT__ "PCCreate_GAMG"
1251 PETSC_EXTERN PetscErrorCode PCCreate_GAMG(PC pc)
1252 {
1253   PetscErrorCode ierr;
1254   PC_GAMG        *pc_gamg;
1255   PC_MG          *mg;
1256 
1257   PetscFunctionBegin;
1258   /* register AMG type */
1259   ierr = PCGAMGInitializePackage();CHKERRQ(ierr);
1260 
1261   /* PCGAMG is an inherited class of PCMG. Initialize pc as PCMG */
1262   ierr = PCSetType(pc, PCMG);CHKERRQ(ierr);
1263   ierr = PetscObjectChangeTypeName((PetscObject)pc, PCGAMG);CHKERRQ(ierr);
1264 
1265   /* create a supporting struct and attach it to pc */
1266   ierr         = PetscNewLog(pc,&pc_gamg);CHKERRQ(ierr);
1267   mg           = (PC_MG*)pc->data;
1268   mg->galerkin = 2;             /* Use Galerkin, but it is computed externally from PCMG by GAMG code */
1269   mg->innerctx = pc_gamg;
1270 
1271   ierr = PetscNewLog(pc,&pc_gamg->ops);CHKERRQ(ierr);
1272 
1273   pc_gamg->setup_count = 0;
1274   /* these should be in subctx but repartitioning needs simple arrays */
1275   pc_gamg->data_sz = 0;
1276   pc_gamg->data    = 0;
1277 
1278   /* overwrite the pointers of PCMG by the functions of base class PCGAMG */
1279   pc->ops->setfromoptions = PCSetFromOptions_GAMG;
1280   pc->ops->setup          = PCSetUp_GAMG;
1281   pc->ops->reset          = PCReset_GAMG;
1282   pc->ops->destroy        = PCDestroy_GAMG;
1283   mg->view                = PCView_GAMG;
1284 
1285   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetProcEqLim_C",PCGAMGSetProcEqLim_GAMG);CHKERRQ(ierr);
1286   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetCoarseEqLim_C",PCGAMGSetCoarseEqLim_GAMG);CHKERRQ(ierr);
1287   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetRepartitioning_C",PCGAMGSetRepartitioning_GAMG);CHKERRQ(ierr);
1288   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetReuseInterpolation_C",PCGAMGSetReuseInterpolation_GAMG);CHKERRQ(ierr);
1289   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetUseASMAggs_C",PCGAMGSetUseASMAggs_GAMG);CHKERRQ(ierr);
1290   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetThreshold_C",PCGAMGSetThreshold_GAMG);CHKERRQ(ierr);
1291   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetType_C",PCGAMGSetType_GAMG);CHKERRQ(ierr);
1292   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGGetType_C",PCGAMGGetType_GAMG);CHKERRQ(ierr);
1293   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCGAMGSetNlevels_C",PCGAMGSetNlevels_GAMG);CHKERRQ(ierr);
1294   pc_gamg->repart           = PETSC_FALSE;
1295   pc_gamg->reuse_prol       = PETSC_FALSE;
1296   pc_gamg->use_aggs_in_gasm = PETSC_FALSE;
1297   pc_gamg->min_eq_proc      = 50;
1298   pc_gamg->coarse_eq_limit  = 50;
1299   pc_gamg->threshold        = 0.;
1300   pc_gamg->Nlevels          = GAMG_MAXLEVELS;
1301   pc_gamg->current_level    = 0; /* don't need to init really */
1302   pc_gamg->ops->createlevel = PCGAMGCreateLevel_GAMG;
1303 
1304   /* PCSetUp_GAMG assumes that the type has been set, so set it to the default now */
1305   ierr = PCGAMGSetType(pc,PCGAMGAGG);CHKERRQ(ierr);
1306   PetscFunctionReturn(0);
1307 }
1308 
1309 #undef __FUNCT__
1310 #define __FUNCT__ "PCGAMGInitializePackage"
1311 /*@C
1312  PCGAMGInitializePackage - This function initializes everything in the PCGAMG package. It is called
1313     from PetscDLLibraryRegister() when using dynamic libraries, and on the first call to PCCreate_GAMG()
1314     when using static libraries.
1315 
1316  Level: developer
1317 
1318  .keywords: PC, PCGAMG, initialize, package
1319  .seealso: PetscInitialize()
1320 @*/
1321 PetscErrorCode PCGAMGInitializePackage(void)
1322 {
1323   PetscErrorCode ierr;
1324 
1325   PetscFunctionBegin;
1326   if (PCGAMGPackageInitialized) PetscFunctionReturn(0);
1327   PCGAMGPackageInitialized = PETSC_TRUE;
1328   ierr = PetscFunctionListAdd(&GAMGList,PCGAMGGEO,PCCreateGAMG_GEO);CHKERRQ(ierr);
1329   ierr = PetscFunctionListAdd(&GAMGList,PCGAMGAGG,PCCreateGAMG_AGG);CHKERRQ(ierr);
1330   ierr = PetscFunctionListAdd(&GAMGList,PCGAMGCLASSICAL,PCCreateGAMG_Classical);CHKERRQ(ierr);
1331   ierr = PetscRegisterFinalize(PCGAMGFinalizePackage);CHKERRQ(ierr);
1332 
1333   /* general events */
1334   ierr = PetscLogEventRegister("PCGAMGGraph_AGG", 0, &PC_GAMGGraph_AGG);CHKERRQ(ierr);
1335   ierr = PetscLogEventRegister("PCGAMGGraph_GEO", PC_CLASSID, &PC_GAMGGraph_GEO);CHKERRQ(ierr);
1336   ierr = PetscLogEventRegister("PCGAMGCoarse_AGG", PC_CLASSID, &PC_GAMGCoarsen_AGG);CHKERRQ(ierr);
1337   ierr = PetscLogEventRegister("PCGAMGCoarse_GEO", PC_CLASSID, &PC_GAMGCoarsen_GEO);CHKERRQ(ierr);
1338   ierr = PetscLogEventRegister("PCGAMGProl_AGG", PC_CLASSID, &PC_GAMGProlongator_AGG);CHKERRQ(ierr);
1339   ierr = PetscLogEventRegister("PCGAMGProl_GEO", PC_CLASSID, &PC_GAMGProlongator_GEO);CHKERRQ(ierr);
1340   ierr = PetscLogEventRegister("PCGAMGPOpt_AGG", PC_CLASSID, &PC_GAMGOptProlongator_AGG);CHKERRQ(ierr);
1341 
1342 #if defined PETSC_GAMG_USE_LOG
1343   ierr = PetscLogEventRegister("GAMG: createProl", PC_CLASSID, &petsc_gamg_setup_events[SET1]);CHKERRQ(ierr);
1344   ierr = PetscLogEventRegister("  Graph", PC_CLASSID, &petsc_gamg_setup_events[GRAPH]);CHKERRQ(ierr);
1345   /* PetscLogEventRegister("    G.Mat", PC_CLASSID, &petsc_gamg_setup_events[GRAPH_MAT]); */
1346   /* PetscLogEventRegister("    G.Filter", PC_CLASSID, &petsc_gamg_setup_events[GRAPH_FILTER]); */
1347   /* PetscLogEventRegister("    G.Square", PC_CLASSID, &petsc_gamg_setup_events[GRAPH_SQR]); */
1348   ierr = PetscLogEventRegister("  MIS/Agg", PC_CLASSID, &petsc_gamg_setup_events[SET4]);CHKERRQ(ierr);
1349   ierr = PetscLogEventRegister("  geo: growSupp", PC_CLASSID, &petsc_gamg_setup_events[SET5]);CHKERRQ(ierr);
1350   ierr = PetscLogEventRegister("  geo: triangle", PC_CLASSID, &petsc_gamg_setup_events[SET6]);CHKERRQ(ierr);
1351   ierr = PetscLogEventRegister("    search&set", PC_CLASSID, &petsc_gamg_setup_events[FIND_V]);CHKERRQ(ierr);
1352   ierr = PetscLogEventRegister("  SA: col data", PC_CLASSID, &petsc_gamg_setup_events[SET7]);CHKERRQ(ierr);
1353   ierr = PetscLogEventRegister("  SA: frmProl0", PC_CLASSID, &petsc_gamg_setup_events[SET8]);CHKERRQ(ierr);
1354   ierr = PetscLogEventRegister("  SA: smooth", PC_CLASSID, &petsc_gamg_setup_events[SET9]);CHKERRQ(ierr);
1355   ierr = PetscLogEventRegister("GAMG: partLevel", PC_CLASSID, &petsc_gamg_setup_events[SET2]);CHKERRQ(ierr);
1356   ierr = PetscLogEventRegister("  repartition", PC_CLASSID, &petsc_gamg_setup_events[SET12]);CHKERRQ(ierr);
1357   ierr = PetscLogEventRegister("  Invert-Sort", PC_CLASSID, &petsc_gamg_setup_events[SET13]);CHKERRQ(ierr);
1358   ierr = PetscLogEventRegister("  Move A", PC_CLASSID, &petsc_gamg_setup_events[SET14]);CHKERRQ(ierr);
1359   ierr = PetscLogEventRegister("  Move P", PC_CLASSID, &petsc_gamg_setup_events[SET15]);CHKERRQ(ierr);
1360 
1361   /* PetscLogEventRegister(" PL move data", PC_CLASSID, &petsc_gamg_setup_events[SET13]); */
1362   /* PetscLogEventRegister("GAMG: fix", PC_CLASSID, &petsc_gamg_setup_events[SET10]); */
1363   /* PetscLogEventRegister("GAMG: set levels", PC_CLASSID, &petsc_gamg_setup_events[SET11]); */
1364   /* create timer stages */
1365 #if defined GAMG_STAGES
1366   {
1367     char     str[32];
1368     PetscInt lidx;
1369     sprintf(str,"MG Level %d (finest)",0);
1370     ierr = PetscLogStageRegister(str, &gamg_stages[0]);CHKERRQ(ierr);
1371     for (lidx=1; lidx<9; lidx++) {
1372       sprintf(str,"MG Level %d",lidx);
1373       ierr = PetscLogStageRegister(str, &gamg_stages[lidx]);CHKERRQ(ierr);
1374     }
1375   }
1376 #endif
1377 #endif
1378   PetscFunctionReturn(0);
1379 }
1380 
1381 #undef __FUNCT__
1382 #define __FUNCT__ "PCGAMGFinalizePackage"
1383 /*@C
1384  PCGAMGFinalizePackage - This function frees everything from the PCGAMG package. It is
1385     called from PetscFinalize() automatically.
1386 
1387  Level: developer
1388 
1389  .keywords: Petsc, destroy, package
1390  .seealso: PetscFinalize()
1391 @*/
1392 PetscErrorCode PCGAMGFinalizePackage(void)
1393 {
1394   PetscErrorCode ierr;
1395 
1396   PetscFunctionBegin;
1397   PCGAMGPackageInitialized = PETSC_FALSE;
1398   ierr = PetscFunctionListDestroy(&GAMGList);CHKERRQ(ierr);
1399   PetscFunctionReturn(0);
1400 }
1401 
1402 #undef __FUNCT__
1403 #define __FUNCT__ "PCGAMGRegister"
1404 /*@C
1405  PCGAMGRegister - Register a PCGAMG implementation.
1406 
1407  Input Parameters:
1408  + type - string that will be used as the name of the GAMG type.
1409  - create - function for creating the gamg context.
1410 
1411   Level: advanced
1412 
1413  .seealso: PCGAMGType, PCGAMG, PCGAMGSetType()
1414 @*/
1415 PetscErrorCode PCGAMGRegister(PCGAMGType type, PetscErrorCode (*create)(PC))
1416 {
1417   PetscErrorCode ierr;
1418 
1419   PetscFunctionBegin;
1420   ierr = PCGAMGInitializePackage();CHKERRQ(ierr);
1421   ierr = PetscFunctionListAdd(&GAMGList,type,create);CHKERRQ(ierr);
1422   PetscFunctionReturn(0);
1423 }
1424 
1425