xref: /petsc/src/mat/impls/baij/mpi/baijov.c (revision 3e7ff0edd3573be01c8c0fa32db97c3db8fa5c8d)
1 
2 /*
3    Routines to compute overlapping regions of a parallel MPI matrix
4   and to find submatrices that were shared across processors.
5 */
6 #include <../src/mat/impls/baij/mpi/mpibaij.h>
7 #include <petscbt.h>
8 
9 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Local(Mat,PetscInt,char**,PetscInt*,PetscInt**);
10 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Receive(Mat,PetscInt,PetscInt**,PetscInt**,PetscInt*);
11 extern PetscErrorCode MatGetRow_MPIBAIJ(Mat,PetscInt,PetscInt*,PetscInt**,PetscScalar**);
12 extern PetscErrorCode MatRestoreRow_MPIBAIJ(Mat,PetscInt,PetscInt*,PetscInt**,PetscScalar**);
13 
14 #undef __FUNCT__
15 #define __FUNCT__ "MatIncreaseOverlap_MPIBAIJ"
16 PetscErrorCode MatIncreaseOverlap_MPIBAIJ(Mat C,PetscInt imax,IS is[],PetscInt ov)
17 {
18   PetscErrorCode ierr;
19   PetscInt       i,N=C->cmap->N, bs=C->rmap->bs;
20   IS             *is_new;
21 
22   PetscFunctionBegin;
23   ierr = PetscMalloc1(imax,&is_new);CHKERRQ(ierr);
24   /* Convert the indices into block format */
25   ierr = ISCompressIndicesGeneral(N,C->rmap->n,bs,imax,is,is_new);CHKERRQ(ierr);
26   if (ov < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Negative overlap specified\n");
27   for (i=0; i<ov; ++i) {
28     ierr = MatIncreaseOverlap_MPIBAIJ_Once(C,imax,is_new);CHKERRQ(ierr);
29   }
30   for (i=0; i<imax; i++) {ierr = ISDestroy(&is[i]);CHKERRQ(ierr);}
31   ierr = ISExpandIndicesGeneral(N,N,bs,imax,is_new,is);CHKERRQ(ierr);
32   for (i=0; i<imax; i++) {ierr = ISDestroy(&is_new[i]);CHKERRQ(ierr);}
33   ierr = PetscFree(is_new);CHKERRQ(ierr);
34   PetscFunctionReturn(0);
35 }
36 
37 /*
38   Sample message format:
39   If a processor A wants processor B to process some elements corresponding
40   to index sets is[1], is[5]
41   mesg [0] = 2   (no of index sets in the mesg)
42   -----------
43   mesg [1] = 1 => is[1]
44   mesg [2] = sizeof(is[1]);
45   -----------
46   mesg [5] = 5  => is[5]
47   mesg [6] = sizeof(is[5]);
48   -----------
49   mesg [7]
50   mesg [n]  data(is[1])
51   -----------
52   mesg[n+1]
53   mesg[m]  data(is[5])
54   -----------
55 
56   Notes:
57   nrqs - no of requests sent (or to be sent out)
58   nrqr - no of requests recieved (which have to be or which have been processed
59 */
60 #undef __FUNCT__
61 #define __FUNCT__ "MatIncreaseOverlap_MPIBAIJ_Once"
62 PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Once(Mat C,PetscInt imax,IS is[])
63 {
64   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
65   const PetscInt **idx,*idx_i;
66   PetscInt       *n,*w3,*w4,**data,len;
67   PetscErrorCode ierr;
68   PetscMPIInt    size,rank,tag1,tag2,*w2,*w1,nrqr;
69   PetscInt       Mbs,i,j,k,**rbuf,row,proc=-1,nrqs,msz,**outdat,**ptr;
70   PetscInt       *ctr,*pa,*tmp,*isz,*isz1,**xdata,**rbuf2,*d_p;
71   PetscMPIInt    *onodes1,*olengths1,*onodes2,*olengths2;
72   PetscBT        *table;
73   MPI_Comm       comm;
74   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2;
75   MPI_Status     *s_status,*recv_status;
76   char           *t_p;
77 
78   PetscFunctionBegin;
79   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
80   size = c->size;
81   rank = c->rank;
82   Mbs  = c->Mbs;
83 
84   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
85   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
86 
87   ierr = PetscMalloc2(imax+1,&idx,imax,&n);CHKERRQ(ierr);
88 
89   for (i=0; i<imax; i++) {
90     ierr = ISGetIndices(is[i],&idx[i]);CHKERRQ(ierr);
91     ierr = ISGetLocalSize(is[i],&n[i]);CHKERRQ(ierr);
92   }
93 
94   /* evaluate communication - mesg to who,length of mesg, and buffer space
95      required. Based on this, buffers are allocated, and data copied into them*/
96   ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);
97   for (i=0; i<imax; i++) {
98     ierr  = PetscMemzero(w4,size*sizeof(PetscInt));CHKERRQ(ierr); /* initialise work vector*/
99     idx_i = idx[i];
100     len   = n[i];
101     for (j=0; j<len; j++) {
102       row = idx_i[j];
103       if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index set cannot have negative entries");
104       ierr = PetscLayoutFindOwner(C->rmap,row*C->rmap->bs,&proc);CHKERRQ(ierr);
105       w4[proc]++;
106     }
107     for (j=0; j<size; j++) {
108       if (w4[j]) { w1[j] += w4[j]; w3[j]++;}
109     }
110   }
111 
112   nrqs     = 0;              /* no of outgoing messages */
113   msz      = 0;              /* total mesg length (for all proc */
114   w1[rank] = 0;              /* no mesg sent to itself */
115   w3[rank] = 0;
116   for (i=0; i<size; i++) {
117     if (w1[i])  {w2[i] = 1; nrqs++;} /* there exists a message to proc i */
118   }
119   /* pa - is list of processors to communicate with */
120   ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr);
121   for (i=0,j=0; i<size; i++) {
122     if (w1[i]) {pa[j] = i; j++;}
123   }
124 
125   /* Each message would have a header = 1 + 2*(no of IS) + data */
126   for (i=0; i<nrqs; i++) {
127     j      = pa[i];
128     w1[j] += w2[j] + 2*w3[j];
129     msz   += w1[j];
130   }
131 
132   /* Determine the number of messages to expect, their lengths, from from-ids */
133   ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
134   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
135 
136   /* Now post the Irecvs corresponding to these messages */
137   ierr = PetscPostIrecvInt(comm,tag1,nrqr,onodes1,olengths1,&rbuf,&r_waits1);CHKERRQ(ierr);
138 
139   /* Allocate Memory for outgoing messages */
140   ierr = PetscMalloc4(size,&outdat,size,&ptr,msz,&tmp,size,&ctr);CHKERRQ(ierr);
141   ierr = PetscMemzero(outdat,size*sizeof(PetscInt*));CHKERRQ(ierr);
142   ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
143   {
144     PetscInt *iptr = tmp,ict  = 0;
145     for (i=0; i<nrqs; i++) {
146       j         = pa[i];
147       iptr     +=  ict;
148       outdat[j] = iptr;
149       ict       = w1[j];
150     }
151   }
152 
153   /* Form the outgoing messages */
154   /*plug in the headers*/
155   for (i=0; i<nrqs; i++) {
156     j            = pa[i];
157     outdat[j][0] = 0;
158     ierr         = PetscMemzero(outdat[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
159     ptr[j]       = outdat[j] + 2*w3[j] + 1;
160   }
161 
162   /* Memory for doing local proc's work*/
163   {
164     ierr = PetscCalloc5(imax,&table, imax,&data, imax,&isz, Mbs*imax,&d_p, (Mbs/PETSC_BITS_PER_BYTE+1)*imax,&t_p);CHKERRQ(ierr);
165 
166     for (i=0; i<imax; i++) {
167       table[i] = t_p + (Mbs/PETSC_BITS_PER_BYTE+1)*i;
168       data[i]  = d_p + (Mbs)*i;
169     }
170   }
171 
172   /* Parse the IS and update local tables and the outgoing buf with the data*/
173   {
174     PetscInt n_i,*data_i,isz_i,*outdat_j,ctr_j;
175     PetscBT  table_i;
176 
177     for (i=0; i<imax; i++) {
178       ierr    = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
179       n_i     = n[i];
180       table_i = table[i];
181       idx_i   = idx[i];
182       data_i  = data[i];
183       isz_i   = isz[i];
184       for (j=0; j<n_i; j++) {   /* parse the indices of each IS */
185         row  = idx_i[j];
186         ierr = PetscLayoutFindOwner(C->rmap,row*C->rmap->bs,&proc);CHKERRQ(ierr);
187         if (proc != rank) { /* copy to the outgoing buffer */
188           ctr[proc]++;
189           *ptr[proc] = row;
190           ptr[proc]++;
191         } else { /* Update the local table */
192           if (!PetscBTLookupSet(table_i,row)) data_i[isz_i++] = row;
193         }
194       }
195       /* Update the headers for the current IS */
196       for (j=0; j<size; j++) { /* Can Optimise this loop by using pa[] */
197         if ((ctr_j = ctr[j])) {
198           outdat_j        = outdat[j];
199           k               = ++outdat_j[0];
200           outdat_j[2*k]   = ctr_j;
201           outdat_j[2*k-1] = i;
202         }
203       }
204       isz[i] = isz_i;
205     }
206   }
207 
208   /*  Now  post the sends */
209   ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
210   for (i=0; i<nrqs; ++i) {
211     j    = pa[i];
212     ierr = MPI_Isend(outdat[j],w1[j],MPIU_INT,j,tag1,comm,s_waits1+i);CHKERRQ(ierr);
213   }
214 
215   /* No longer need the original indices*/
216   for (i=0; i<imax; ++i) {
217     ierr = ISRestoreIndices(is[i],idx+i);CHKERRQ(ierr);
218   }
219   ierr = PetscFree2(idx,n);CHKERRQ(ierr);
220 
221   for (i=0; i<imax; ++i) {
222     ierr = ISDestroy(&is[i]);CHKERRQ(ierr);
223   }
224 
225   /* Do Local work*/
226   ierr = MatIncreaseOverlap_MPIBAIJ_Local(C,imax,table,isz,data);CHKERRQ(ierr);
227 
228   /* Receive messages*/
229   ierr = PetscMalloc1(nrqr+1,&recv_status);CHKERRQ(ierr);
230   if (nrqr) {ierr = MPI_Waitall(nrqr,r_waits1,recv_status);CHKERRQ(ierr);}
231 
232   ierr = PetscMalloc1(nrqs+1,&s_status);CHKERRQ(ierr);
233   if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status);CHKERRQ(ierr);}
234 
235   /* Phase 1 sends are complete - deallocate buffers */
236   ierr = PetscFree4(outdat,ptr,tmp,ctr);CHKERRQ(ierr);
237   ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
238 
239   ierr = PetscMalloc1(nrqr+1,&xdata);CHKERRQ(ierr);
240   ierr = PetscMalloc1(nrqr+1,&isz1);CHKERRQ(ierr);
241   ierr = MatIncreaseOverlap_MPIBAIJ_Receive(C,nrqr,rbuf,xdata,isz1);CHKERRQ(ierr);
242   ierr = PetscFree(rbuf[0]);CHKERRQ(ierr);
243   ierr = PetscFree(rbuf);CHKERRQ(ierr);
244 
245   /* Send the data back*/
246   /* Do a global reduction to know the buffer space req for incoming messages*/
247   {
248     PetscMPIInt *rw1;
249 
250     ierr = PetscCalloc1(size,&rw1);CHKERRQ(ierr);
251 
252     for (i=0; i<nrqr; ++i) {
253       proc = recv_status[i].MPI_SOURCE;
254       if (proc != onodes1[i]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MPI_SOURCE mismatch");
255       rw1[proc] = isz1[i];
256     }
257 
258     ierr = PetscFree(onodes1);CHKERRQ(ierr);
259     ierr = PetscFree(olengths1);CHKERRQ(ierr);
260 
261     /* Determine the number of messages to expect, their lengths, from from-ids */
262     ierr = PetscGatherMessageLengths(comm,nrqr,nrqs,rw1,&onodes2,&olengths2);CHKERRQ(ierr);
263     ierr = PetscFree(rw1);CHKERRQ(ierr);
264   }
265   /* Now post the Irecvs corresponding to these messages */
266   ierr = PetscPostIrecvInt(comm,tag2,nrqs,onodes2,olengths2,&rbuf2,&r_waits2);CHKERRQ(ierr);
267 
268   /*  Now  post the sends */
269   ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
270   for (i=0; i<nrqr; ++i) {
271     j    = recv_status[i].MPI_SOURCE;
272     ierr = MPI_Isend(xdata[i],isz1[i],MPIU_INT,j,tag2,comm,s_waits2+i);CHKERRQ(ierr);
273   }
274 
275   /* receive work done on other processors*/
276   {
277     PetscMPIInt idex;
278     PetscInt    is_no,ct1,max,*rbuf2_i,isz_i,*data_i,jmax;
279     PetscBT     table_i;
280     MPI_Status  *status2;
281 
282     ierr = PetscMalloc1(PetscMax(nrqr,nrqs)+1,&status2);CHKERRQ(ierr);
283     for (i=0; i<nrqs; ++i) {
284       ierr = MPI_Waitany(nrqs,r_waits2,&idex,status2+i);CHKERRQ(ierr);
285       /* Process the message*/
286       rbuf2_i = rbuf2[idex];
287       ct1     = 2*rbuf2_i[0]+1;
288       jmax    = rbuf2[idex][0];
289       for (j=1; j<=jmax; j++) {
290         max     = rbuf2_i[2*j];
291         is_no   = rbuf2_i[2*j-1];
292         isz_i   = isz[is_no];
293         data_i  = data[is_no];
294         table_i = table[is_no];
295         for (k=0; k<max; k++,ct1++) {
296           row = rbuf2_i[ct1];
297           if (!PetscBTLookupSet(table_i,row)) data_i[isz_i++] = row;
298         }
299         isz[is_no] = isz_i;
300       }
301     }
302     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,status2);CHKERRQ(ierr);}
303     ierr = PetscFree(status2);CHKERRQ(ierr);
304   }
305 
306   for (i=0; i<imax; ++i) {
307     ierr = ISCreateGeneral(PETSC_COMM_SELF,isz[i],data[i],PETSC_COPY_VALUES,is+i);CHKERRQ(ierr);
308   }
309 
310 
311   ierr = PetscFree(onodes2);CHKERRQ(ierr);
312   ierr = PetscFree(olengths2);CHKERRQ(ierr);
313 
314   ierr = PetscFree(pa);CHKERRQ(ierr);
315   ierr = PetscFree(rbuf2[0]);CHKERRQ(ierr);
316   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
317   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
318   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
319   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
320   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
321   ierr = PetscFree5(table,data,isz,d_p,t_p);CHKERRQ(ierr);
322   ierr = PetscFree(s_status);CHKERRQ(ierr);
323   ierr = PetscFree(recv_status);CHKERRQ(ierr);
324   ierr = PetscFree(xdata[0]);CHKERRQ(ierr);
325   ierr = PetscFree(xdata);CHKERRQ(ierr);
326   ierr = PetscFree(isz1);CHKERRQ(ierr);
327   PetscFunctionReturn(0);
328 }
329 
330 #undef __FUNCT__
331 #define __FUNCT__ "MatIncreaseOverlap_MPIBAIJ_Local"
332 /*
333    MatIncreaseOverlap_MPIBAIJ_Local - Called by MatincreaseOverlap, to do
334        the work on the local processor.
335 
336      Inputs:
337       C      - MAT_MPIBAIJ;
338       imax - total no of index sets processed at a time;
339       table  - an array of char - size = Mbs bits.
340 
341      Output:
342       isz    - array containing the count of the solution elements corresponding
343                to each index set;
344       data   - pointer to the solutions
345 */
346 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Local(Mat C,PetscInt imax,PetscBT *table,PetscInt *isz,PetscInt **data)
347 {
348   Mat_MPIBAIJ *c = (Mat_MPIBAIJ*)C->data;
349   Mat         A  = c->A,B = c->B;
350   Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)B->data;
351   PetscInt    start,end,val,max,rstart,cstart,*ai,*aj;
352   PetscInt    *bi,*bj,*garray,i,j,k,row,*data_i,isz_i;
353   PetscBT     table_i;
354 
355   PetscFunctionBegin;
356   rstart = c->rstartbs;
357   cstart = c->cstartbs;
358   ai     = a->i;
359   aj     = a->j;
360   bi     = b->i;
361   bj     = b->j;
362   garray = c->garray;
363 
364 
365   for (i=0; i<imax; i++) {
366     data_i  = data[i];
367     table_i = table[i];
368     isz_i   = isz[i];
369     for (j=0,max=isz[i]; j<max; j++) {
370       row   = data_i[j] - rstart;
371       start = ai[row];
372       end   = ai[row+1];
373       for (k=start; k<end; k++) { /* Amat */
374         val = aj[k] + cstart;
375         if (!PetscBTLookupSet(table_i,val)) data_i[isz_i++] = val;
376       }
377       start = bi[row];
378       end   = bi[row+1];
379       for (k=start; k<end; k++) { /* Bmat */
380         val = garray[bj[k]];
381         if (!PetscBTLookupSet(table_i,val)) data_i[isz_i++] = val;
382       }
383     }
384     isz[i] = isz_i;
385   }
386   PetscFunctionReturn(0);
387 }
388 #undef __FUNCT__
389 #define __FUNCT__ "MatIncreaseOverlap_MPIBAIJ_Receive"
390 /*
391       MatIncreaseOverlap_MPIBAIJ_Receive - Process the recieved messages,
392          and return the output
393 
394          Input:
395            C    - the matrix
396            nrqr - no of messages being processed.
397            rbuf - an array of pointers to the recieved requests
398 
399          Output:
400            xdata - array of messages to be sent back
401            isz1  - size of each message
402 
403   For better efficiency perhaps we should malloc separately each xdata[i],
404 then if a remalloc is required we need only copy the data for that one row
405 rather than all previous rows as it is now where a single large chunck of
406 memory is used.
407 
408 */
409 static PetscErrorCode MatIncreaseOverlap_MPIBAIJ_Receive(Mat C,PetscInt nrqr,PetscInt **rbuf,PetscInt **xdata,PetscInt * isz1)
410 {
411   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
412   Mat            A  = c->A,B = c->B;
413   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)B->data;
414   PetscErrorCode ierr;
415   PetscInt       rstart,cstart,*ai,*aj,*bi,*bj,*garray,i,j,k;
416   PetscInt       row,total_sz,ct,ct1,ct2,ct3,mem_estimate,oct2,l,start,end;
417   PetscInt       val,max1,max2,Mbs,no_malloc =0,*tmp,new_estimate,ctr;
418   PetscInt       *rbuf_i,kmax,rbuf_0;
419   PetscBT        xtable;
420 
421   PetscFunctionBegin;
422   Mbs    = c->Mbs;
423   rstart = c->rstartbs;
424   cstart = c->cstartbs;
425   ai     = a->i;
426   aj     = a->j;
427   bi     = b->i;
428   bj     = b->j;
429   garray = c->garray;
430 
431 
432   for (i=0,ct=0,total_sz=0; i<nrqr; ++i) {
433     rbuf_i =  rbuf[i];
434     rbuf_0 =  rbuf_i[0];
435     ct    += rbuf_0;
436     for (j=1; j<=rbuf_0; j++) total_sz += rbuf_i[2*j];
437   }
438 
439   if (c->Mbs) max1 = ct*(a->nz +b->nz)/c->Mbs;
440   else        max1 = 1;
441   mem_estimate = 3*((total_sz > max1 ? total_sz : max1)+1);
442   ierr         = PetscMalloc1(mem_estimate,&xdata[0]);CHKERRQ(ierr);
443   ++no_malloc;
444   ierr = PetscBTCreate(Mbs,&xtable);CHKERRQ(ierr);
445   ierr = PetscMemzero(isz1,nrqr*sizeof(PetscInt));CHKERRQ(ierr);
446 
447   ct3 = 0;
448   for (i=0; i<nrqr; i++) { /* for easch mesg from proc i */
449     rbuf_i =  rbuf[i];
450     rbuf_0 =  rbuf_i[0];
451     ct1    =  2*rbuf_0+1;
452     ct2    =  ct1;
453     ct3   += ct1;
454     for (j=1; j<=rbuf_0; j++) { /* for each IS from proc i*/
455       ierr = PetscBTMemzero(Mbs,xtable);CHKERRQ(ierr);
456       oct2 = ct2;
457       kmax = rbuf_i[2*j];
458       for (k=0; k<kmax; k++,ct1++) {
459         row = rbuf_i[ct1];
460         if (!PetscBTLookupSet(xtable,row)) {
461           if (!(ct3 < mem_estimate)) {
462             new_estimate = (PetscInt)(1.5*mem_estimate)+1;
463             ierr         = PetscMalloc1(new_estimate,&tmp);CHKERRQ(ierr);
464             ierr         = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(PetscInt));CHKERRQ(ierr);
465             ierr         = PetscFree(xdata[0]);CHKERRQ(ierr);
466             xdata[0]     = tmp;
467             mem_estimate = new_estimate; ++no_malloc;
468             for (ctr=1; ctr<=i; ctr++) xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];
469           }
470           xdata[i][ct2++] = row;
471           ct3++;
472         }
473       }
474       for (k=oct2,max2=ct2; k<max2; k++)  {
475         row   = xdata[i][k] - rstart;
476         start = ai[row];
477         end   = ai[row+1];
478         for (l=start; l<end; l++) {
479           val = aj[l] + cstart;
480           if (!PetscBTLookupSet(xtable,val)) {
481             if (!(ct3 < mem_estimate)) {
482               new_estimate = (PetscInt)(1.5*mem_estimate)+1;
483               ierr         = PetscMalloc1(new_estimate,&tmp);CHKERRQ(ierr);
484               ierr         = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(PetscInt));CHKERRQ(ierr);
485               ierr         = PetscFree(xdata[0]);CHKERRQ(ierr);
486               xdata[0]     = tmp;
487               mem_estimate = new_estimate; ++no_malloc;
488               for (ctr=1; ctr<=i; ctr++) xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];
489             }
490             xdata[i][ct2++] = val;
491             ct3++;
492           }
493         }
494         start = bi[row];
495         end   = bi[row+1];
496         for (l=start; l<end; l++) {
497           val = garray[bj[l]];
498           if (!PetscBTLookupSet(xtable,val)) {
499             if (!(ct3 < mem_estimate)) {
500               new_estimate = (PetscInt)(1.5*mem_estimate)+1;
501               ierr         = PetscMalloc1(new_estimate,&tmp);CHKERRQ(ierr);
502               ierr         = PetscMemcpy(tmp,xdata[0],mem_estimate*sizeof(PetscInt));CHKERRQ(ierr);
503               ierr         = PetscFree(xdata[0]);CHKERRQ(ierr);
504               xdata[0]     = tmp;
505               mem_estimate = new_estimate; ++no_malloc;
506               for (ctr =1; ctr <=i; ctr++) xdata[ctr] = xdata[ctr-1] + isz1[ctr-1];
507             }
508             xdata[i][ct2++] = val;
509             ct3++;
510           }
511         }
512       }
513       /* Update the header*/
514       xdata[i][2*j]   = ct2 - oct2; /* Undo the vector isz1 and use only a var*/
515       xdata[i][2*j-1] = rbuf_i[2*j-1];
516     }
517     xdata[i][0] = rbuf_0;
518     xdata[i+1]  = xdata[i] + ct2;
519     isz1[i]     = ct2; /* size of each message */
520   }
521   ierr = PetscBTDestroy(&xtable);CHKERRQ(ierr);
522   ierr = PetscInfo3(C,"Allocated %D bytes, required %D, no of mallocs = %D\n",mem_estimate,ct3,no_malloc);CHKERRQ(ierr);
523   PetscFunctionReturn(0);
524 }
525 
526 #undef __FUNCT__
527 #define __FUNCT__ "MatGetSubMatrices_MPIBAIJ"
528 PetscErrorCode MatGetSubMatrices_MPIBAIJ(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,Mat *submat[])
529 {
530   IS             *isrow_new,*iscol_new;
531   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
532   PetscErrorCode ierr;
533   PetscInt       nmax,nstages_local,nstages,i,pos,max_no,ncol,nrow,N=C->cmap->N,bs=C->rmap->bs;
534   PetscBool      colflag,*allcolumns,*allrows;
535 
536   PetscFunctionBegin;
537   /* Currently, unsorted column indices will result in inverted column indices in the resulting submatrices. */
538   for (i = 0; i < ismax; ++i) {
539     PetscBool sorted;
540     ierr = ISSorted(iscol[i], &sorted);CHKERRQ(ierr);
541     if (!sorted) SETERRQ1(((PetscObject)iscol[i])->comm, PETSC_ERR_SUP, "Column index set %D not sorted", i);
542   }
543   /* The compression and expansion should be avoided. Doesn't point
544      out errors, might change the indices, hence buggey */
545   ierr = PetscMalloc2(ismax+1,&isrow_new,ismax+1,&iscol_new);CHKERRQ(ierr);
546   ierr = ISCompressIndicesGeneral(N,C->rmap->n,bs,ismax,isrow,isrow_new);CHKERRQ(ierr);
547   ierr = ISCompressIndicesGeneral(N,C->cmap->n,bs,ismax,iscol,iscol_new);CHKERRQ(ierr);
548 
549   /* Check for special case: each processor gets entire matrix columns */
550   ierr = PetscMalloc2(ismax+1,&allcolumns,ismax+1,&allrows);CHKERRQ(ierr);
551   for (i=0; i<ismax; i++) {
552     ierr = ISIdentity(iscol[i],&colflag);CHKERRQ(ierr);
553     ierr = ISGetLocalSize(iscol[i],&ncol);CHKERRQ(ierr);
554     if (colflag && ncol == C->cmap->N) allcolumns[i] = PETSC_TRUE;
555     else allcolumns[i] = PETSC_FALSE;
556 
557     ierr = ISIdentity(isrow[i],&colflag);CHKERRQ(ierr);
558     ierr = ISGetLocalSize(isrow[i],&nrow);CHKERRQ(ierr);
559     if (colflag && nrow == C->rmap->N) allrows[i] = PETSC_TRUE;
560     else allrows[i] = PETSC_FALSE;
561   }
562 
563   /* Allocate memory to hold all the submatrices */
564   if (scall != MAT_REUSE_MATRIX) {
565     ierr = PetscMalloc1(ismax+1,submat);CHKERRQ(ierr);
566   }
567   /* Determine the number of stages through which submatrices are done */
568   nmax = 20*1000000 / (c->Nbs * sizeof(PetscInt));
569   if (!nmax) nmax = 1;
570   nstages_local = ismax/nmax + ((ismax % nmax) ? 1 : 0);
571 
572   /* Make sure every processor loops through the nstages */
573   ierr = MPI_Allreduce(&nstages_local,&nstages,1,MPIU_INT,MPI_MAX,PetscObjectComm((PetscObject)C));CHKERRQ(ierr);
574   for (i=0,pos=0; i<nstages; i++) {
575     if (pos+nmax <= ismax) max_no = nmax;
576     else if (pos == ismax) max_no = 0;
577     else                   max_no = ismax-pos;
578     ierr = MatGetSubMatrices_MPIBAIJ_local(C,max_no,isrow_new+pos,iscol_new+pos,scall,allrows+pos,allcolumns+pos,*submat+pos);CHKERRQ(ierr);
579     pos += max_no;
580   }
581 
582   for (i=0; i<ismax; i++) {
583     ierr = ISDestroy(&isrow_new[i]);CHKERRQ(ierr);
584     ierr = ISDestroy(&iscol_new[i]);CHKERRQ(ierr);
585   }
586   ierr = PetscFree2(isrow_new,iscol_new);CHKERRQ(ierr);
587   ierr = PetscFree2(allcolumns,allrows);CHKERRQ(ierr);
588   PetscFunctionReturn(0);
589 }
590 
591 #if defined(PETSC_USE_CTABLE)
592 #undef __FUNCT__
593 #define __FUNCT__ "PetscGetProc"
594 PetscErrorCode PetscGetProc(const PetscInt row, const PetscMPIInt size, const PetscInt proc_gnode[], PetscMPIInt *rank)
595 {
596   PetscInt       nGlobalNd = proc_gnode[size];
597   PetscMPIInt    fproc;
598   PetscErrorCode ierr;
599 
600   PetscFunctionBegin;
601   ierr = PetscMPIIntCast((PetscInt)(((float)row * (float)size / (float)nGlobalNd + 0.5)),&fproc);CHKERRQ(ierr);
602   if (fproc > size) fproc = size;
603   while (row < proc_gnode[fproc] || row >= proc_gnode[fproc+1]) {
604     if (row < proc_gnode[fproc]) fproc--;
605     else                         fproc++;
606   }
607   *rank = fproc;
608   PetscFunctionReturn(0);
609 }
610 #endif
611 
612 /* -------------------------------------------------------------------------*/
613 /* This code is used for BAIJ and SBAIJ matrices (unfortunate dependency) */
614 #undef __FUNCT__
615 #define __FUNCT__ "MatGetSubMatrices_MPIBAIJ_local"
616 PetscErrorCode MatGetSubMatrices_MPIBAIJ_local(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,PetscBool *allrows,PetscBool *allcolumns,Mat *submats)
617 {
618   Mat_MPIBAIJ    *c = (Mat_MPIBAIJ*)C->data;
619   Mat            A  = c->A;
620   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)c->B->data,*mat;
621   const PetscInt **irow,**icol,*irow_i;
622   PetscInt       *nrow,*ncol,*w3,*w4,start;
623   PetscErrorCode ierr;
624   PetscMPIInt    size,tag0,tag1,tag2,tag3,*w1,*w2,nrqr,idex,end,proc;
625   PetscInt       **sbuf1,**sbuf2,rank,i,j,k,l,ct1,ct2,**rbuf1,row;
626   PetscInt       nrqs,msz,**ptr,*req_size,*ctr,*pa,*tmp,tcol;
627   PetscInt       **rbuf3,*req_source,**sbuf_aj,**rbuf2,max1,max2;
628   PetscInt       **lens,is_no,ncols,*cols,mat_i,*mat_j,tmp2,jmax;
629   PetscInt       ctr_j,*sbuf1_j,*sbuf_aj_i,*rbuf1_i,kmax,*lens_i;
630   PetscInt       bs     =C->rmap->bs,bs2=c->bs2,*a_j=a->j,*b_j=b->j,*cworkA,*cworkB;
631   PetscInt       cstart = c->cstartbs,nzA,nzB,*a_i=a->i,*b_i=b->i,imark;
632   PetscInt       *bmap  = c->garray,ctmp,rstart=c->rstartbs;
633   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2,*r_waits3,*s_waits3;
634   MPI_Status     *r_status1,*r_status2,*s_status1,*s_status3,*s_status2,*r_status3;
635   MPI_Comm       comm;
636   PetscBool      flag;
637   PetscMPIInt    *onodes1,*olengths1;
638   PetscBool      ijonly=c->ijonly; /* private flag indicates only matrix data structures are requested */
639 
640   /* variables below are used for the matrix numerical values - case of !ijonly */
641   MPI_Request *r_waits4,*s_waits4;
642   MPI_Status  *r_status4,*s_status4;
643   MatScalar   **rbuf4,**sbuf_aa,*vals,*mat_a = NULL,*sbuf_aa_i,*vworkA = NULL,*vworkB = NULL;
644   MatScalar   *a_a=a->a,*b_a=b->a;
645 
646 #if defined(PETSC_USE_CTABLE)
647   PetscInt   tt;
648   PetscTable *rmap,*cmap,rmap_i,cmap_i=NULL;
649 #else
650   PetscInt **cmap,*cmap_i=NULL,*rtable,*rmap_i,**rmap, Mbs = c->Mbs;
651 #endif
652 
653   PetscFunctionBegin;
654   ierr = PetscObjectGetComm((PetscObject)C,&comm);CHKERRQ(ierr);
655   tag0 = ((PetscObject)C)->tag;
656   size = c->size;
657   rank = c->rank;
658 
659   /* Get some new tags to keep the communication clean */
660   ierr = PetscObjectGetNewTag((PetscObject)C,&tag1);CHKERRQ(ierr);
661   ierr = PetscObjectGetNewTag((PetscObject)C,&tag2);CHKERRQ(ierr);
662   ierr = PetscObjectGetNewTag((PetscObject)C,&tag3);CHKERRQ(ierr);
663 
664 #if defined(PETSC_USE_CTABLE)
665   ierr = PetscMalloc4(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol);CHKERRQ(ierr);
666 #else
667   ierr = PetscMalloc5(ismax,&irow,ismax,&icol,ismax,&nrow,ismax,&ncol,Mbs+1,&rtable);CHKERRQ(ierr);
668   /* Create hash table for the mapping :row -> proc*/
669   for (i=0,j=0; i<size; i++) {
670     jmax = C->rmap->range[i+1]/bs;
671     for (; j<jmax; j++) rtable[j] = i;
672   }
673 #endif
674 
675   for (i=0; i<ismax; i++) {
676     if (allrows[i]) {
677       irow[i] = NULL;
678       nrow[i] = C->rmap->N/bs;
679     } else {
680       ierr = ISGetIndices(isrow[i],&irow[i]);CHKERRQ(ierr);
681       ierr = ISGetLocalSize(isrow[i],&nrow[i]);CHKERRQ(ierr);
682     }
683 
684     if (allcolumns[i]) {
685       icol[i] = NULL;
686       ncol[i] = C->cmap->N/bs;
687     } else {
688       ierr = ISGetIndices(iscol[i],&icol[i]);CHKERRQ(ierr);
689       ierr = ISGetLocalSize(iscol[i],&ncol[i]);CHKERRQ(ierr);
690     }
691   }
692 
693   /* evaluate communication - mesg to who,length of mesg,and buffer space
694      required. Based on this, buffers are allocated, and data copied into them*/
695   ierr = PetscCalloc4(size,&w1,size,&w2,size,&w3,size,&w4);CHKERRQ(ierr);
696   for (i=0; i<ismax; i++) {
697     ierr   = PetscMemzero(w4,size*sizeof(PetscInt));CHKERRQ(ierr); /* initialise work vector*/
698     jmax   = nrow[i];
699     irow_i = irow[i];
700     for (j=0; j<jmax; j++) {
701       if (allrows[i]) row = j;
702       else row = irow_i[j];
703 
704 #if defined(PETSC_USE_CTABLE)
705       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
706 #else
707       proc = rtable[row];
708 #endif
709       w4[proc]++;
710     }
711     for (j=0; j<size; j++) {
712       if (w4[j]) { w1[j] += w4[j];  w3[j]++;}
713     }
714   }
715 
716   nrqs     = 0;              /* no of outgoing messages */
717   msz      = 0;              /* total mesg length for all proc */
718   w1[rank] = 0;              /* no mesg sent to intself */
719   w3[rank] = 0;
720   for (i=0; i<size; i++) {
721     if (w1[i])  { w2[i] = 1; nrqs++;} /* there exists a message to proc i */
722   }
723   ierr = PetscMalloc1(nrqs+1,&pa);CHKERRQ(ierr); /*(proc -array)*/
724   for (i=0,j=0; i<size; i++) {
725     if (w1[i]) { pa[j] = i; j++; }
726   }
727 
728   /* Each message would have a header = 1 + 2*(no of IS) + data */
729   for (i=0; i<nrqs; i++) {
730     j     = pa[i];
731     w1[j] += w2[j] + 2* w3[j];
732     msz   += w1[j];
733   }
734 
735   /* Determine the number of messages to expect, their lengths, from from-ids */
736   ierr = PetscGatherNumberOfMessages(comm,w2,w1,&nrqr);CHKERRQ(ierr);
737   ierr = PetscGatherMessageLengths(comm,nrqs,nrqr,w1,&onodes1,&olengths1);CHKERRQ(ierr);
738 
739   /* Now post the Irecvs corresponding to these messages */
740   ierr = PetscPostIrecvInt(comm,tag0,nrqr,onodes1,olengths1,&rbuf1,&r_waits1);CHKERRQ(ierr);
741 
742   ierr = PetscFree(onodes1);CHKERRQ(ierr);
743   ierr = PetscFree(olengths1);CHKERRQ(ierr);
744 
745   /* Allocate Memory for outgoing messages */
746   ierr = PetscMalloc4(size,&sbuf1,size,&ptr,2*msz,&tmp,size,&ctr);CHKERRQ(ierr);
747   ierr = PetscMemzero(sbuf1,size*sizeof(PetscInt*));CHKERRQ(ierr);
748   ierr = PetscMemzero(ptr,size*sizeof(PetscInt*));CHKERRQ(ierr);
749   {
750     PetscInt *iptr = tmp,ict = 0;
751     for (i=0; i<nrqs; i++) {
752       j        = pa[i];
753       iptr    += ict;
754       sbuf1[j] = iptr;
755       ict      = w1[j];
756     }
757   }
758 
759   /* Form the outgoing messages */
760   /* Initialise the header space */
761   for (i=0; i<nrqs; i++) {
762     j           = pa[i];
763     sbuf1[j][0] = 0;
764     ierr        = PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));CHKERRQ(ierr);
765     ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
766   }
767 
768   /* Parse the isrow and copy data into outbuf */
769   for (i=0; i<ismax; i++) {
770     ierr   = PetscMemzero(ctr,size*sizeof(PetscInt));CHKERRQ(ierr);
771     irow_i = irow[i];
772     jmax   = nrow[i];
773     for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
774       if (allrows[i]) row = j;
775       else row = irow_i[j];
776 
777 #if defined(PETSC_USE_CTABLE)
778       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
779 #else
780       proc = rtable[row];
781 #endif
782       if (proc != rank) { /* copy to the outgoing buf*/
783         ctr[proc]++;
784         *ptr[proc] = row;
785         ptr[proc]++;
786       }
787     }
788     /* Update the headers for the current IS */
789     for (j=0; j<size; j++) { /* Can Optimise this loop too */
790       if ((ctr_j = ctr[j])) {
791         sbuf1_j        = sbuf1[j];
792         k              = ++sbuf1_j[0];
793         sbuf1_j[2*k]   = ctr_j;
794         sbuf1_j[2*k-1] = i;
795       }
796     }
797   }
798 
799   /*  Now  post the sends */
800   ierr = PetscMalloc1(nrqs+1,&s_waits1);CHKERRQ(ierr);
801   for (i=0; i<nrqs; ++i) {
802     j    = pa[i];
803     ierr = MPI_Isend(sbuf1[j],w1[j],MPIU_INT,j,tag0,comm,s_waits1+i);CHKERRQ(ierr);
804   }
805 
806   /* Post Recieves to capture the buffer size */
807   ierr     = PetscMalloc1(nrqs+1,&r_waits2);CHKERRQ(ierr);
808   ierr     = PetscMalloc1(nrqs+1,&rbuf2);CHKERRQ(ierr);
809   rbuf2[0] = tmp + msz;
810   for (i=1; i<nrqs; ++i) {
811     j        = pa[i];
812     rbuf2[i] = rbuf2[i-1]+w1[pa[i-1]];
813   }
814   for (i=0; i<nrqs; ++i) {
815     j    = pa[i];
816     ierr = MPI_Irecv(rbuf2[i],w1[j],MPIU_INT,j,tag1,comm,r_waits2+i);CHKERRQ(ierr);
817   }
818 
819   /* Send to other procs the buf size they should allocate */
820 
821   /* Receive messages*/
822   ierr = PetscMalloc1(nrqr+1,&s_waits2);CHKERRQ(ierr);
823   ierr = PetscMalloc1(nrqr+1,&r_status1);CHKERRQ(ierr);
824   ierr = PetscMalloc3(nrqr+1,&sbuf2,nrqr,&req_size,nrqr,&req_source);CHKERRQ(ierr);
825   {
826     Mat_SeqBAIJ *sA  = (Mat_SeqBAIJ*)c->A->data,*sB = (Mat_SeqBAIJ*)c->B->data;
827     PetscInt    *sAi = sA->i,*sBi = sB->i,id,*sbuf2_i;
828 
829     for (i=0; i<nrqr; ++i) {
830       ierr = MPI_Waitany(nrqr,r_waits1,&idex,r_status1+i);CHKERRQ(ierr);
831 
832       req_size[idex] = 0;
833       rbuf1_i        = rbuf1[idex];
834       start          = 2*rbuf1_i[0] + 1;
835       ierr           = MPI_Get_count(r_status1+i,MPIU_INT,&end);CHKERRQ(ierr);
836       ierr           = PetscMalloc1(end,&sbuf2[idex]);CHKERRQ(ierr);
837       sbuf2_i        = sbuf2[idex];
838       for (j=start; j<end; j++) {
839         id              = rbuf1_i[j] - rstart;
840         ncols           = sAi[id+1] - sAi[id] + sBi[id+1] - sBi[id];
841         sbuf2_i[j]      = ncols;
842         req_size[idex] += ncols;
843       }
844       req_source[idex] = r_status1[i].MPI_SOURCE;
845       /* form the header */
846       sbuf2_i[0] = req_size[idex];
847       for (j=1; j<start; j++) sbuf2_i[j] = rbuf1_i[j];
848       ierr = MPI_Isend(sbuf2_i,end,MPIU_INT,req_source[idex],tag1,comm,s_waits2+i);CHKERRQ(ierr);
849     }
850   }
851   ierr = PetscFree(r_status1);CHKERRQ(ierr);
852   ierr = PetscFree(r_waits1);CHKERRQ(ierr);
853 
854   /*  recv buffer sizes */
855   /* Receive messages*/
856   ierr = PetscMalloc1(nrqs+1,&rbuf3);CHKERRQ(ierr);
857   ierr = PetscMalloc1(nrqs+1,&r_waits3);CHKERRQ(ierr);
858   ierr = PetscMalloc1(nrqs+1,&r_status2);CHKERRQ(ierr);
859   if (!ijonly) {
860     ierr = PetscMalloc1(nrqs+1,&rbuf4);CHKERRQ(ierr);
861     ierr = PetscMalloc1(nrqs+1,&r_waits4);CHKERRQ(ierr);
862   }
863 
864   for (i=0; i<nrqs; ++i) {
865     ierr = MPI_Waitany(nrqs,r_waits2,&idex,r_status2+i);CHKERRQ(ierr);
866     ierr = PetscMalloc1(rbuf2[idex][0],&rbuf3[idex]);CHKERRQ(ierr);
867     ierr = MPI_Irecv(rbuf3[idex],rbuf2[idex][0],MPIU_INT,r_status2[i].MPI_SOURCE,tag2,comm,r_waits3+idex);CHKERRQ(ierr);
868     if (!ijonly) {
869       ierr = PetscMalloc1(rbuf2[idex][0]*bs2,&rbuf4[idex]);CHKERRQ(ierr);
870       ierr = MPI_Irecv(rbuf4[idex],rbuf2[idex][0]*bs2,MPIU_MATSCALAR,r_status2[i].MPI_SOURCE,tag3,comm,r_waits4+idex);CHKERRQ(ierr);
871     }
872   }
873   ierr = PetscFree(r_status2);CHKERRQ(ierr);
874   ierr = PetscFree(r_waits2);CHKERRQ(ierr);
875 
876   /* Wait on sends1 and sends2 */
877   ierr = PetscMalloc1(nrqs+1,&s_status1);CHKERRQ(ierr);
878   ierr = PetscMalloc1(nrqr+1,&s_status2);CHKERRQ(ierr);
879 
880   if (nrqs) {ierr = MPI_Waitall(nrqs,s_waits1,s_status1);CHKERRQ(ierr);}
881   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits2,s_status2);CHKERRQ(ierr);}
882   ierr = PetscFree(s_status1);CHKERRQ(ierr);
883   ierr = PetscFree(s_status2);CHKERRQ(ierr);
884   ierr = PetscFree(s_waits1);CHKERRQ(ierr);
885   ierr = PetscFree(s_waits2);CHKERRQ(ierr);
886 
887   /* Now allocate buffers for a->j, and send them off */
888   ierr = PetscMalloc1(nrqr+1,&sbuf_aj);CHKERRQ(ierr);
889   for (i=0,j=0; i<nrqr; i++) j += req_size[i];
890   ierr = PetscMalloc1(j+1,&sbuf_aj[0]);CHKERRQ(ierr);
891   for (i=1; i<nrqr; i++) sbuf_aj[i] = sbuf_aj[i-1] + req_size[i-1];
892 
893   ierr = PetscMalloc1(nrqr+1,&s_waits3);CHKERRQ(ierr);
894   {
895     for (i=0; i<nrqr; i++) {
896       rbuf1_i   = rbuf1[i];
897       sbuf_aj_i = sbuf_aj[i];
898       ct1       = 2*rbuf1_i[0] + 1;
899       ct2       = 0;
900       for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
901         kmax = rbuf1[i][2*j];
902         for (k=0; k<kmax; k++,ct1++) {
903           row    = rbuf1_i[ct1] - rstart;
904           nzA    = a_i[row+1] - a_i[row];     nzB = b_i[row+1] - b_i[row];
905           ncols  = nzA + nzB;
906           cworkA = a_j + a_i[row]; cworkB = b_j + b_i[row];
907 
908           /* load the column indices for this row into cols*/
909           cols = sbuf_aj_i + ct2;
910           for (l=0; l<nzB; l++) {
911             if ((ctmp = bmap[cworkB[l]]) < cstart) cols[l] = ctmp;
912             else break;
913           }
914           imark = l;
915           for (l=0; l<nzA; l++)   cols[imark+l] = cstart + cworkA[l];
916           for (l=imark; l<nzB; l++) cols[nzA+l] = bmap[cworkB[l]];
917           ct2 += ncols;
918         }
919       }
920       ierr = MPI_Isend(sbuf_aj_i,req_size[i],MPIU_INT,req_source[i],tag2,comm,s_waits3+i);CHKERRQ(ierr);
921     }
922   }
923   ierr = PetscMalloc1(nrqs+1,&r_status3);CHKERRQ(ierr);
924   ierr = PetscMalloc1(nrqr+1,&s_status3);CHKERRQ(ierr);
925 
926   /* Allocate buffers for a->a, and send them off */
927   if (!ijonly) {
928     ierr = PetscMalloc1(nrqr+1,&sbuf_aa);CHKERRQ(ierr);
929     for (i=0,j=0; i<nrqr; i++) j += req_size[i];
930     ierr = PetscMalloc1((j+1)*bs2,&sbuf_aa[0]);CHKERRQ(ierr);
931     for (i=1; i<nrqr; i++) sbuf_aa[i] = sbuf_aa[i-1] + req_size[i-1]*bs2;
932 
933     ierr = PetscMalloc1(nrqr+1,&s_waits4);CHKERRQ(ierr);
934     {
935       for (i=0; i<nrqr; i++) {
936         rbuf1_i   = rbuf1[i];
937         sbuf_aa_i = sbuf_aa[i];
938         ct1       = 2*rbuf1_i[0]+1;
939         ct2       = 0;
940         for (j=1,max1=rbuf1_i[0]; j<=max1; j++) {
941           kmax = rbuf1_i[2*j];
942           for (k=0; k<kmax; k++,ct1++) {
943             row    = rbuf1_i[ct1] - rstart;
944             nzA    = a_i[row+1] - a_i[row];     nzB = b_i[row+1] - b_i[row];
945             ncols  = nzA + nzB;
946             cworkA = a_j + a_i[row];     cworkB = b_j + b_i[row];
947             vworkA = a_a + a_i[row]*bs2; vworkB = b_a + b_i[row]*bs2;
948 
949             /* load the column values for this row into vals*/
950             vals = sbuf_aa_i+ct2*bs2;
951             for (l=0; l<nzB; l++) {
952               if ((bmap[cworkB[l]]) < cstart) {
953                 ierr = PetscMemcpy(vals+l*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
954               } else break;
955             }
956             imark = l;
957             for (l=0; l<nzA; l++) {
958               ierr = PetscMemcpy(vals+(imark+l)*bs2,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
959             }
960             for (l=imark; l<nzB; l++) {
961               ierr = PetscMemcpy(vals+(nzA+l)*bs2,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
962             }
963             ct2 += ncols;
964           }
965         }
966         ierr = MPI_Isend(sbuf_aa_i,req_size[i]*bs2,MPIU_MATSCALAR,req_source[i],tag3,comm,s_waits4+i);CHKERRQ(ierr);
967       }
968     }
969     ierr = PetscMalloc1(nrqs+1,&r_status4);CHKERRQ(ierr);
970     ierr = PetscMalloc1(nrqr+1,&s_status4);CHKERRQ(ierr);
971   }
972   ierr = PetscFree(rbuf1[0]);CHKERRQ(ierr);
973   ierr = PetscFree(rbuf1);CHKERRQ(ierr);
974 
975   /* Form the matrix */
976   /* create col map: global col of C -> local col of submatrices */
977   {
978     const PetscInt *icol_i;
979 #if defined(PETSC_USE_CTABLE)
980     ierr = PetscMalloc1(1+ismax,&cmap);CHKERRQ(ierr);
981     for (i=0; i<ismax; i++) {
982       if (!allcolumns[i]) {
983         ierr   = PetscTableCreate(ncol[i]+1,c->Nbs+1,&cmap[i]);CHKERRQ(ierr);
984         jmax   = ncol[i];
985         icol_i = icol[i];
986         cmap_i = cmap[i];
987         for (j=0; j<jmax; j++) {
988           ierr = PetscTableAdd(cmap_i,icol_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
989         }
990       } else {
991         cmap[i] = NULL;
992       }
993     }
994 #else
995     ierr = PetscMalloc1(ismax,&cmap);CHKERRQ(ierr);
996     for (i=0; i<ismax; i++) {
997       if (!allcolumns[i]) {
998         ierr   = PetscCalloc1(c->Nbs,&cmap[i]);CHKERRQ(ierr);
999         jmax   = ncol[i];
1000         icol_i = icol[i];
1001         cmap_i = cmap[i];
1002         for (j=0; j<jmax; j++) {
1003           cmap_i[icol_i[j]] = j+1;
1004         }
1005       } else { /* allcolumns[i] */
1006         cmap[i] = NULL;
1007       }
1008     }
1009 #endif
1010   }
1011 
1012   /* Create lens which is required for MatCreate... */
1013   for (i=0,j=0; i<ismax; i++) j += nrow[i];
1014   ierr    = PetscMalloc((1+ismax)*sizeof(PetscInt*)+ j*sizeof(PetscInt),&lens);CHKERRQ(ierr);
1015   lens[0] = (PetscInt*)(lens + ismax);
1016   ierr    = PetscMemzero(lens[0],j*sizeof(PetscInt));CHKERRQ(ierr);
1017   for (i=1; i<ismax; i++) lens[i] = lens[i-1] + nrow[i-1];
1018 
1019   /* Update lens from local data */
1020   for (i=0; i<ismax; i++) {
1021     jmax = nrow[i];
1022     if (!allcolumns[i]) cmap_i = cmap[i];
1023     irow_i = irow[i];
1024     lens_i = lens[i];
1025     for (j=0; j<jmax; j++) {
1026       if (allrows[i]) row = j;
1027       else row = irow_i[j];
1028 
1029 #if defined(PETSC_USE_CTABLE)
1030       ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1031 #else
1032       proc = rtable[row];
1033 #endif
1034       if (proc == rank) {
1035         /* Get indices from matA and then from matB */
1036         row    = row - rstart;
1037         nzA    = a_i[row+1] - a_i[row];     nzB = b_i[row+1] - b_i[row];
1038         cworkA =  a_j + a_i[row]; cworkB = b_j + b_i[row];
1039         if (!allcolumns[i]) {
1040 #if defined(PETSC_USE_CTABLE)
1041           for (k=0; k<nzA; k++) {
1042             ierr = PetscTableFind(cmap_i,cstart+cworkA[k]+1,&tt);CHKERRQ(ierr);
1043             if (tt) lens_i[j]++;
1044           }
1045           for (k=0; k<nzB; k++) {
1046             ierr = PetscTableFind(cmap_i,bmap[cworkB[k]]+1,&tt);CHKERRQ(ierr);
1047             if (tt) lens_i[j]++;
1048           }
1049 
1050 #else
1051           for (k=0; k<nzA; k++) {
1052             if (cmap_i[cstart + cworkA[k]]) lens_i[j]++;
1053           }
1054           for (k=0; k<nzB; k++) {
1055             if (cmap_i[bmap[cworkB[k]]]) lens_i[j]++;
1056           }
1057 #endif
1058         } else { /* allcolumns */
1059           lens_i[j] = nzA + nzB;
1060         }
1061       }
1062     }
1063   }
1064 #if defined(PETSC_USE_CTABLE)
1065   /* Create row map*/
1066   ierr = PetscMalloc1(1+ismax,&rmap);CHKERRQ(ierr);
1067   for (i=0; i<ismax; i++) {
1068     ierr = PetscTableCreate(nrow[i]+1,c->Mbs+1,&rmap[i]);CHKERRQ(ierr);
1069   }
1070 #else
1071   /* Create row map*/
1072   ierr    = PetscMalloc((1+ismax)*sizeof(PetscInt*)+ ismax*Mbs*sizeof(PetscInt),&rmap);CHKERRQ(ierr);
1073   rmap[0] = (PetscInt*)(rmap + ismax);
1074   ierr    = PetscMemzero(rmap[0],ismax*Mbs*sizeof(PetscInt));CHKERRQ(ierr);
1075   for (i=1; i<ismax; i++) rmap[i] = rmap[i-1] + Mbs;
1076 #endif
1077   for (i=0; i<ismax; i++) {
1078     irow_i = irow[i];
1079     jmax   = nrow[i];
1080 #if defined(PETSC_USE_CTABLE)
1081     rmap_i = rmap[i];
1082     for (j=0; j<jmax; j++) {
1083       if (allrows[i]) {
1084         ierr = PetscTableAdd(rmap_i,j+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1085       } else {
1086         ierr = PetscTableAdd(rmap_i,irow_i[j]+1,j+1,INSERT_VALUES);CHKERRQ(ierr);
1087       }
1088     }
1089 #else
1090     rmap_i = rmap[i];
1091     for (j=0; j<jmax; j++) {
1092       if (allrows[i]) rmap_i[j] = j;
1093       else rmap_i[irow_i[j]] = j;
1094     }
1095 #endif
1096   }
1097 
1098   /* Update lens from offproc data */
1099   {
1100     PetscInt    *rbuf2_i,*rbuf3_i,*sbuf1_i;
1101     PetscMPIInt ii;
1102 
1103     for (tmp2=0; tmp2<nrqs; tmp2++) {
1104       ierr    = MPI_Waitany(nrqs,r_waits3,&ii,r_status3+tmp2);CHKERRQ(ierr);
1105       idex    = pa[ii];
1106       sbuf1_i = sbuf1[idex];
1107       jmax    = sbuf1_i[0];
1108       ct1     = 2*jmax+1;
1109       ct2     = 0;
1110       rbuf2_i = rbuf2[ii];
1111       rbuf3_i = rbuf3[ii];
1112       for (j=1; j<=jmax; j++) {
1113         is_no  = sbuf1_i[2*j-1];
1114         max1   = sbuf1_i[2*j];
1115         lens_i = lens[is_no];
1116         if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1117         rmap_i = rmap[is_no];
1118         for (k=0; k<max1; k++,ct1++) {
1119 #if defined(PETSC_USE_CTABLE)
1120           ierr = PetscTableFind(rmap_i,sbuf1_i[ct1]+1,&row);CHKERRQ(ierr);
1121           row--;
1122           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1123 #else
1124           row = rmap_i[sbuf1_i[ct1]];  /* the val in the new matrix to be */
1125 #endif
1126           max2 = rbuf2_i[ct1];
1127           for (l=0; l<max2; l++,ct2++) {
1128             if (!allcolumns[is_no]) {
1129 #if defined(PETSC_USE_CTABLE)
1130               ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tt);CHKERRQ(ierr);
1131               if (tt) lens_i[row]++;
1132 #else
1133               if (cmap_i[rbuf3_i[ct2]]) lens_i[row]++;
1134 #endif
1135             } else { /* allcolumns */
1136               lens_i[row]++;
1137             }
1138           }
1139         }
1140       }
1141     }
1142   }
1143   ierr = PetscFree(r_status3);CHKERRQ(ierr);
1144   ierr = PetscFree(r_waits3);CHKERRQ(ierr);
1145   if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits3,s_status3);CHKERRQ(ierr);}
1146   ierr = PetscFree(s_status3);CHKERRQ(ierr);
1147   ierr = PetscFree(s_waits3);CHKERRQ(ierr);
1148 
1149   /* Create the submatrices */
1150   if (scall == MAT_REUSE_MATRIX) {
1151     if (ijonly) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP," MAT_REUSE_MATRIX and ijonly is not supported yet");
1152     /*
1153         Assumes new rows are same length as the old rows, hence bug!
1154     */
1155     for (i=0; i<ismax; i++) {
1156       mat = (Mat_SeqBAIJ*)(submats[i]->data);
1157       if ((mat->mbs != nrow[i]) || (mat->nbs != ncol[i] || C->rmap->bs != bs)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
1158       ierr = PetscMemcmp(mat->ilen,lens[i],mat->mbs *sizeof(PetscInt),&flag);CHKERRQ(ierr);
1159       if (!flag) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Cannot reuse matrix. wrong no of nonzeros");
1160       /* Initial matrix as if empty */
1161       ierr = PetscMemzero(mat->ilen,mat->mbs*sizeof(PetscInt));CHKERRQ(ierr);
1162 
1163       submats[i]->factortype = C->factortype;
1164     }
1165   } else {
1166     PetscInt bs_tmp;
1167     if (ijonly) bs_tmp = 1;
1168     else        bs_tmp = bs;
1169     for (i=0; i<ismax; i++) {
1170       ierr = MatCreate(PETSC_COMM_SELF,submats+i);CHKERRQ(ierr);
1171       ierr = MatSetSizes(submats[i],nrow[i]*bs_tmp,ncol[i]*bs_tmp,nrow[i]*bs_tmp,ncol[i]*bs_tmp);CHKERRQ(ierr);
1172       ierr = MatSetType(submats[i],((PetscObject)A)->type_name);CHKERRQ(ierr);
1173       ierr = MatSeqBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr);
1174       ierr = MatSeqSBAIJSetPreallocation(submats[i],bs_tmp,0,lens[i]);CHKERRQ(ierr); /* this subroutine is used by SBAIJ routines */
1175     }
1176   }
1177 
1178   /* Assemble the matrices */
1179   /* First assemble the local rows */
1180   {
1181     PetscInt  ilen_row,*imat_ilen,*imat_j,*imat_i;
1182     MatScalar *imat_a = NULL;
1183 
1184     for (i=0; i<ismax; i++) {
1185       mat       = (Mat_SeqBAIJ*)submats[i]->data;
1186       imat_ilen = mat->ilen;
1187       imat_j    = mat->j;
1188       imat_i    = mat->i;
1189       if (!ijonly) imat_a = mat->a;
1190       if (!allcolumns[i]) cmap_i = cmap[i];
1191       rmap_i = rmap[i];
1192       irow_i = irow[i];
1193       jmax   = nrow[i];
1194       for (j=0; j<jmax; j++) {
1195         if (allrows[i]) row = j;
1196         else row = irow_i[j];
1197 
1198 #if defined(PETSC_USE_CTABLE)
1199         ierr = PetscGetProc(row,size,c->rangebs,&proc);CHKERRQ(ierr);
1200 #else
1201         proc = rtable[row];
1202 #endif
1203         if (proc == rank) {
1204           row    = row - rstart;
1205           nzA    = a_i[row+1] - a_i[row];
1206           nzB    = b_i[row+1] - b_i[row];
1207           cworkA = a_j + a_i[row];
1208           cworkB = b_j + b_i[row];
1209           if (!ijonly) {
1210             vworkA = a_a + a_i[row]*bs2;
1211             vworkB = b_a + b_i[row]*bs2;
1212           }
1213 #if defined(PETSC_USE_CTABLE)
1214           ierr = PetscTableFind(rmap_i,row+rstart+1,&row);CHKERRQ(ierr);
1215           row--;
1216           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1217 #else
1218           row = rmap_i[row + rstart];
1219 #endif
1220           mat_i = imat_i[row];
1221           if (!ijonly) mat_a = imat_a + mat_i*bs2;
1222           mat_j    = imat_j + mat_i;
1223           ilen_row = imat_ilen[row];
1224 
1225           /* load the column indices for this row into cols*/
1226           if (!allcolumns[i]) {
1227             for (l=0; l<nzB; l++) {
1228               if ((ctmp = bmap[cworkB[l]]) < cstart) {
1229 #if defined(PETSC_USE_CTABLE)
1230                 ierr = PetscTableFind(cmap_i,ctmp+1,&tcol);CHKERRQ(ierr);
1231                 if (tcol) {
1232 #else
1233                 if ((tcol = cmap_i[ctmp])) {
1234 #endif
1235                   *mat_j++ = tcol - 1;
1236                   ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1237                   mat_a   += bs2;
1238                   ilen_row++;
1239                 }
1240               } else break;
1241             }
1242             imark = l;
1243             for (l=0; l<nzA; l++) {
1244 #if defined(PETSC_USE_CTABLE)
1245               ierr = PetscTableFind(cmap_i,cstart+cworkA[l]+1,&tcol);CHKERRQ(ierr);
1246               if (tcol) {
1247 #else
1248               if ((tcol = cmap_i[cstart + cworkA[l]])) {
1249 #endif
1250                 *mat_j++ = tcol - 1;
1251                 if (!ijonly) {
1252                   ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1253                   mat_a += bs2;
1254                 }
1255                 ilen_row++;
1256               }
1257             }
1258             for (l=imark; l<nzB; l++) {
1259 #if defined(PETSC_USE_CTABLE)
1260               ierr = PetscTableFind(cmap_i,bmap[cworkB[l]]+1,&tcol);CHKERRQ(ierr);
1261               if (tcol) {
1262 #else
1263               if ((tcol = cmap_i[bmap[cworkB[l]]])) {
1264 #endif
1265                 *mat_j++ = tcol - 1;
1266                 if (!ijonly) {
1267                   ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1268                   mat_a += bs2;
1269                 }
1270                 ilen_row++;
1271               }
1272             }
1273           } else { /* allcolumns */
1274             for (l=0; l<nzB; l++) {
1275               if ((ctmp = bmap[cworkB[l]]) < cstart) {
1276                 *mat_j++ = ctmp;
1277                 ierr     = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1278                 mat_a   += bs2;
1279                 ilen_row++;
1280               } else break;
1281             }
1282             imark = l;
1283             for (l=0; l<nzA; l++) {
1284               *mat_j++ = cstart+cworkA[l];
1285               if (!ijonly) {
1286                 ierr   = PetscMemcpy(mat_a,vworkA+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1287                 mat_a += bs2;
1288               }
1289               ilen_row++;
1290             }
1291             for (l=imark; l<nzB; l++) {
1292               *mat_j++ = bmap[cworkB[l]];
1293               if (!ijonly) {
1294                 ierr   = PetscMemcpy(mat_a,vworkB+l*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1295                 mat_a += bs2;
1296               }
1297               ilen_row++;
1298             }
1299           }
1300           imat_ilen[row] = ilen_row;
1301         }
1302       }
1303     }
1304   }
1305 
1306   /*   Now assemble the off proc rows*/
1307   {
1308     PetscInt    *sbuf1_i,*rbuf2_i,*rbuf3_i,*imat_ilen,ilen;
1309     PetscInt    *imat_j,*imat_i;
1310     MatScalar   *imat_a = NULL,*rbuf4_i = NULL;
1311     PetscMPIInt ii;
1312 
1313     for (tmp2=0; tmp2<nrqs; tmp2++) {
1314       if (ijonly) ii = tmp2;
1315       else {
1316         ierr = MPI_Waitany(nrqs,r_waits4,&ii,r_status4+tmp2);CHKERRQ(ierr);
1317       }
1318       idex    = pa[ii];
1319       sbuf1_i = sbuf1[idex];
1320       jmax    = sbuf1_i[0];
1321       ct1     = 2*jmax + 1;
1322       ct2     = 0;
1323       rbuf2_i = rbuf2[ii];
1324       rbuf3_i = rbuf3[ii];
1325       if (!ijonly) rbuf4_i = rbuf4[ii];
1326       for (j=1; j<=jmax; j++) {
1327         is_no = sbuf1_i[2*j-1];
1328         if (!allcolumns[is_no]) cmap_i = cmap[is_no];
1329         rmap_i    = rmap[is_no];
1330         mat       = (Mat_SeqBAIJ*)submats[is_no]->data;
1331         imat_ilen = mat->ilen;
1332         imat_j    = mat->j;
1333         imat_i    = mat->i;
1334         if (!ijonly) imat_a = mat->a;
1335         max1 = sbuf1_i[2*j];
1336         for (k=0; k<max1; k++,ct1++) {
1337           row = sbuf1_i[ct1];
1338 #if defined(PETSC_USE_CTABLE)
1339           ierr = PetscTableFind(rmap_i,row+1,&row);CHKERRQ(ierr);
1340           row--;
1341           if (row < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"row not found in table");
1342 #else
1343           row = rmap_i[row];
1344 #endif
1345           ilen  = imat_ilen[row];
1346           mat_i = imat_i[row];
1347           if (!ijonly) mat_a = imat_a + mat_i*bs2;
1348           mat_j = imat_j + mat_i;
1349           max2  = rbuf2_i[ct1];
1350 
1351           if (!allcolumns[is_no]) {
1352             for (l=0; l<max2; l++,ct2++) {
1353 #if defined(PETSC_USE_CTABLE)
1354               ierr = PetscTableFind(cmap_i,rbuf3_i[ct2]+1,&tcol);CHKERRQ(ierr);
1355               if (tcol) {
1356 #else
1357               if ((tcol = cmap_i[rbuf3_i[ct2]])) {
1358 #endif
1359                 *mat_j++ = tcol - 1;
1360                 if (!ijonly) {
1361                   ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1362                   mat_a += bs2;
1363                 }
1364                 ilen++;
1365               }
1366             }
1367           } else { /* allcolumns */
1368             for (l=0; l<max2; l++,ct2++) {
1369               *mat_j++ = rbuf3_i[ct2];
1370               if (!ijonly) {
1371                 ierr   = PetscMemcpy(mat_a,rbuf4_i+ct2*bs2,bs2*sizeof(MatScalar));CHKERRQ(ierr);
1372                 mat_a += bs2;
1373               }
1374               ilen++;
1375             }
1376           }
1377           imat_ilen[row] = ilen;
1378         }
1379       }
1380     }
1381   }
1382   if (!ijonly) {
1383     ierr = PetscFree(r_status4);CHKERRQ(ierr);
1384     ierr = PetscFree(r_waits4);CHKERRQ(ierr);
1385     if (nrqr) {ierr = MPI_Waitall(nrqr,s_waits4,s_status4);CHKERRQ(ierr);}
1386     ierr = PetscFree(s_waits4);CHKERRQ(ierr);
1387     ierr = PetscFree(s_status4);CHKERRQ(ierr);
1388   }
1389 
1390   /* Restore the indices */
1391   for (i=0; i<ismax; i++) {
1392     if (!allrows[i]) {
1393       ierr = ISRestoreIndices(isrow[i],irow+i);CHKERRQ(ierr);
1394     }
1395     if (!allcolumns[i]) {
1396       ierr = ISRestoreIndices(iscol[i],icol+i);CHKERRQ(ierr);
1397     }
1398   }
1399 
1400   /* Destroy allocated memory */
1401 #if defined(PETSC_USE_CTABLE)
1402   ierr = PetscFree4(irow,icol,nrow,ncol);CHKERRQ(ierr);
1403 #else
1404   ierr = PetscFree5(irow,icol,nrow,ncol,rtable);CHKERRQ(ierr);
1405 #endif
1406   ierr = PetscFree4(w1,w2,w3,w4);CHKERRQ(ierr);
1407   ierr = PetscFree(pa);CHKERRQ(ierr);
1408 
1409   ierr = PetscFree4(sbuf1,ptr,tmp,ctr);CHKERRQ(ierr);
1410   ierr = PetscFree(sbuf1);CHKERRQ(ierr);
1411   ierr = PetscFree(rbuf2);CHKERRQ(ierr);
1412   for (i=0; i<nrqr; ++i) {
1413     ierr = PetscFree(sbuf2[i]);CHKERRQ(ierr);
1414   }
1415   for (i=0; i<nrqs; ++i) {
1416     ierr = PetscFree(rbuf3[i]);CHKERRQ(ierr);
1417   }
1418   ierr = PetscFree3(sbuf2,req_size,req_source);CHKERRQ(ierr);
1419   ierr = PetscFree(rbuf3);CHKERRQ(ierr);
1420   ierr = PetscFree(sbuf_aj[0]);CHKERRQ(ierr);
1421   ierr = PetscFree(sbuf_aj);CHKERRQ(ierr);
1422   if (!ijonly) {
1423     for (i=0; i<nrqs; ++i) {ierr = PetscFree(rbuf4[i]);CHKERRQ(ierr);}
1424     ierr = PetscFree(rbuf4);CHKERRQ(ierr);
1425     ierr = PetscFree(sbuf_aa[0]);CHKERRQ(ierr);
1426     ierr = PetscFree(sbuf_aa);CHKERRQ(ierr);
1427   }
1428 
1429 #if defined(PETSC_USE_CTABLE)
1430   for (i=0; i<ismax; i++) {
1431     ierr = PetscTableDestroy((PetscTable*)&rmap[i]);CHKERRQ(ierr);
1432   }
1433 #endif
1434   ierr = PetscFree(rmap);CHKERRQ(ierr);
1435 
1436   for (i=0; i<ismax; i++) {
1437     if (!allcolumns[i]) {
1438 #if defined(PETSC_USE_CTABLE)
1439       ierr = PetscTableDestroy((PetscTable*)&cmap[i]);CHKERRQ(ierr);
1440 #else
1441       ierr = PetscFree(cmap[i]);CHKERRQ(ierr);
1442 #endif
1443     }
1444   }
1445   ierr = PetscFree(cmap);CHKERRQ(ierr);
1446   ierr = PetscFree(lens);CHKERRQ(ierr);
1447 
1448   for (i=0; i<ismax; i++) {
1449     ierr = MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1450     ierr = MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
1451   }
1452 
1453   c->ijonly = PETSC_FALSE; /* set back to the default */
1454   PetscFunctionReturn(0);
1455 }
1456 
1457