Actual source code: mmdense.c

      1: #define PETSCMAT_DLL

      3: /*
      4:    Support for the parallel dense matrix vector multiply
      5: */
     6:  #include src/mat/impls/dense/mpi/mpidense.h

     10: PetscErrorCode MatSetUpMultiply_MPIDense(Mat mat)
     11: {
     12:   Mat_MPIDense *mdn = (Mat_MPIDense*)mat->data;
     14:   IS           from,to;
     15:   Vec          gvec;

     18:   /* Create local vector that is used to scatter into */
     19:   VecCreateSeq(PETSC_COMM_SELF,mat->N,&mdn->lvec);

     21:   /* Create temporary index set for building scatter gather */
     22:   ISCreateStride(mat->comm,mat->N,0,1,&from);
     23:   ISCreateStride(PETSC_COMM_SELF,mat->N,0,1,&to);

     25:   /* Create temporary global vector to generate scatter context */
     26:   /* n    = mdn->cowners[mdn->rank+1] - mdn->cowners[mdn->rank]; */

     28:   VecCreateMPI(mat->comm,mdn->nvec,mat->N,&gvec);

     30:   /* Generate the scatter context */
     31:   VecScatterCreate(gvec,from,mdn->lvec,to,&mdn->Mvctx);
     32:   PetscLogObjectParent(mat,mdn->Mvctx);
     33:   PetscLogObjectParent(mat,mdn->lvec);
     34:   PetscLogObjectParent(mat,from);
     35:   PetscLogObjectParent(mat,to);
     36:   PetscLogObjectParent(mat,gvec);

     38:   ISDestroy(to);
     39:   ISDestroy(from);
     40:   VecDestroy(gvec);
     41:   return(0);
     42: }

     44: EXTERN PetscErrorCode MatGetSubMatrices_MPIDense_Local(Mat,PetscInt,const IS[],const IS[],MatReuse,Mat*);
     47: PetscErrorCode MatGetSubMatrices_MPIDense(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,Mat *submat[])
     48: {
     50:   PetscInt           nmax,nstages_local,nstages,i,pos,max_no;

     53:   /* Allocate memory to hold all the submatrices */
     54:   if (scall != MAT_REUSE_MATRIX) {
     55:     PetscMalloc((ismax+1)*sizeof(Mat),submat);
     56:   }
     57:   /* Determine the number of stages through which submatrices are done */
     58:   nmax          = 20*1000000 / (C->N * sizeof(PetscInt));
     59:   if (!nmax) nmax = 1;
     60:   nstages_local = ismax/nmax + ((ismax % nmax)?1:0);

     62:   /* Make sure every processor loops through the nstages */
     63:   MPI_Allreduce(&nstages_local,&nstages,1,MPIU_INT,MPI_MAX,C->comm);

     66:   for (i=0,pos=0; i<nstages; i++) {
     67:     if (pos+nmax <= ismax) max_no = nmax;
     68:     else if (pos == ismax) max_no = 0;
     69:     else                   max_no = ismax-pos;
     70:     MatGetSubMatrices_MPIDense_Local(C,max_no,isrow+pos,iscol+pos,scall,*submat+pos);
     71:     pos += max_no;
     72:   }
     73:   return(0);
     74: }
     75: /* -------------------------------------------------------------------------*/
     78: PetscErrorCode MatGetSubMatrices_MPIDense_Local(Mat C,PetscInt ismax,const IS isrow[],const IS iscol[],MatReuse scall,Mat *submats)
     79: {
     80:   Mat_MPIDense   *c = (Mat_MPIDense*)C->data;
     81:   Mat            A = c->A;
     82:   Mat_SeqDense   *a = (Mat_SeqDense*)A->data,*mat;
     84:   PetscMPIInt    rank,size,tag0,tag1,idex,end,i;
     85:   PetscInt       N = C->N,rstart = c->rstart,count;
     86:   PetscInt       **irow,**icol,*nrow,*ncol,*w1,*w3,*w4,*rtable,start;
     87:   PetscInt       **sbuf1,m,j,k,l,ct1,**rbuf1,row,proc;
     88:   PetscInt       nrqs,msz,**ptr,*ctr,*pa,*tmp,bsz,nrqr;
     89:   PetscInt       is_no,jmax,*irow_i,**rmap,*rmap_i;
     90:   PetscInt       len,ctr_j,*sbuf1_j,*rbuf1_i;
     91:   MPI_Request    *s_waits1,*r_waits1,*s_waits2,*r_waits2;
     92:   MPI_Status     *r_status1,*r_status2,*s_status1,*s_status2;
     93:   MPI_Comm       comm;
     94:   PetscScalar    **rbuf2,**sbuf2;
     95:   PetscTruth     sorted;

     98:   comm   = C->comm;
     99:   tag0   = C->tag;
    100:   size   = c->size;
    101:   rank   = c->rank;
    102:   m      = C->M;
    103:
    104:   /* Get some new tags to keep the communication clean */
    105:   PetscObjectGetNewTag((PetscObject)C,&tag1);

    107:     /* Check if the col indices are sorted */
    108:   for (i=0; i<ismax; i++) {
    109:     ISSorted(isrow[i],&sorted);
    110:     if (!sorted) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"ISrow is not sorted");
    111:     ISSorted(iscol[i],&sorted);
    112:     if (!sorted) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"IScol is not sorted");
    113:   }

    115:   len    =  2*ismax*(sizeof(PetscInt*)+sizeof(PetscInt)) + (m+1)*sizeof(PetscInt);
    116:   PetscMalloc(len,&irow);
    117:   icol   = irow + ismax;
    118:   nrow   = (PetscInt*)(icol + ismax);
    119:   ncol   = nrow + ismax;
    120:   rtable = ncol + ismax;

    122:   for (i=0; i<ismax; i++) {
    123:     ISGetIndices(isrow[i],&irow[i]);
    124:     ISGetIndices(iscol[i],&icol[i]);
    125:     ISGetLocalSize(isrow[i],&nrow[i]);
    126:     ISGetLocalSize(iscol[i],&ncol[i]);
    127:   }

    129:   /* Create hash table for the mapping :row -> proc*/
    130:   for (i=0,j=0; i<size; i++) {
    131:     jmax = c->rowners[i+1];
    132:     for (; j<jmax; j++) {
    133:       rtable[j] = i;
    134:     }
    135:   }

    137:   /* evaluate communication - mesg to who,length of mesg, and buffer space
    138:      required. Based on this, buffers are allocated, and data copied into them*/
    139:   PetscMalloc(size*4*sizeof(PetscInt),&w1); /* mesg size */
    140:   w3     = w1 + 2*size;      /* no of IS that needs to be sent to proc i */
    141:   w4     = w3 + size;      /* temp work space used in determining w1,  w3 */
    142:   PetscMemzero(w1,size*3*sizeof(PetscInt)); /* initialize work vector*/
    143:   for (i=0; i<ismax; i++) {
    144:     PetscMemzero(w4,size*sizeof(PetscInt)); /* initialize work vector*/
    145:     jmax   = nrow[i];
    146:     irow_i = irow[i];
    147:     for (j=0; j<jmax; j++) {
    148:       row  = irow_i[j];
    149:       proc = rtable[row];
    150:       w4[proc]++;
    151:     }
    152:     for (j=0; j<size; j++) {
    153:       if (w4[j]) { w1[2*j] += w4[j];  w3[j]++;}
    154:     }
    155:   }
    156:
    157:   nrqs       = 0;              /* no of outgoing messages */
    158:   msz        = 0;              /* total mesg length (for all procs) */
    159:   w1[2*rank] = 0;              /* no mesg sent to self */
    160:   w3[rank]   = 0;
    161:   for (i=0; i<size; i++) {
    162:     if (w1[2*i])  { w1[2*i+1] = 1; nrqs++;} /* there exists a message to proc i */
    163:   }
    164:   PetscMalloc((nrqs+1)*sizeof(PetscInt),&pa); /*(proc -array)*/
    165:   for (i=0,j=0; i<size; i++) {
    166:     if (w1[2*i]) { pa[j] = i; j++; }
    167:   }

    169:   /* Each message would have a header = 1 + 2*(no of IS) + data */
    170:   for (i=0; i<nrqs; i++) {
    171:     j       = pa[i];
    172:     w1[2*j] += w1[2*j+1] + 2* w3[j];
    173:     msz     += w1[2*j];
    174:   }
    175:   /* Do a global reduction to determine how many messages to expect*/
    176:   PetscMaxSum(comm,w1,&bsz,&nrqr);

    178:   /* Allocate memory for recv buffers . Prob none if nrqr = 0 ???? */
    179:   len      = (nrqr+1)*sizeof(PetscInt*) + nrqr*bsz*sizeof(PetscInt);
    180:   PetscMalloc(len,&rbuf1);
    181:   rbuf1[0] = (PetscInt*)(rbuf1 + nrqr);
    182:   for (i=1; i<nrqr; ++i) rbuf1[i] = rbuf1[i-1] + bsz;
    183:
    184:   /* Post the receives */
    185:   PetscMalloc((nrqr+1)*sizeof(MPI_Request),&r_waits1);
    186:   for (i=0; i<nrqr; ++i) {
    187:     MPI_Irecv(rbuf1[i],bsz,MPIU_INT,MPI_ANY_SOURCE,tag0,comm,r_waits1+i);
    188:   }

    190:   /* Allocate Memory for outgoing messages */
    191:   len   = 2*size*sizeof(PetscInt*) + 2*msz*sizeof(PetscInt)+ size*sizeof(PetscInt);
    192:   PetscMalloc(len,&sbuf1);
    193:   ptr   = sbuf1 + size;   /* Pointers to the data in outgoing buffers */
    194:   PetscMemzero(sbuf1,2*size*sizeof(PetscInt*));
    195:   /* allocate memory for outgoing data + buf to receive the first reply */
    196:   tmp   = (PetscInt*)(ptr + size);
    197:   ctr   = tmp + 2*msz;

    199:   {
    200:     PetscInt *iptr = tmp,ict = 0;
    201:     for (i=0; i<nrqs; i++) {
    202:       j         = pa[i];
    203:       iptr     += ict;
    204:       sbuf1[j]  = iptr;
    205:       ict       = w1[2*j];
    206:     }
    207:   }

    209:   /* Form the outgoing messages */
    210:   /* Initialize the header space */
    211:   for (i=0; i<nrqs; i++) {
    212:     j           = pa[i];
    213:     sbuf1[j][0] = 0;
    214:     PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));
    215:     ptr[j]      = sbuf1[j] + 2*w3[j] + 1;
    216:   }
    217:
    218:   /* Parse the isrow and copy data into outbuf */
    219:   for (i=0; i<ismax; i++) {
    220:     PetscMemzero(ctr,size*sizeof(PetscInt));
    221:     irow_i = irow[i];
    222:     jmax   = nrow[i];
    223:     for (j=0; j<jmax; j++) {  /* parse the indices of each IS */
    224:       row  = irow_i[j];
    225:       proc = rtable[row];
    226:       if (proc != rank) { /* copy to the outgoing buf*/
    227:         ctr[proc]++;
    228:         *ptr[proc] = row;
    229:         ptr[proc]++;
    230:       }
    231:     }
    232:     /* Update the headers for the current IS */
    233:     for (j=0; j<size; j++) { /* Can Optimise this loop too */
    234:       if ((ctr_j = ctr[j])) {
    235:         sbuf1_j        = sbuf1[j];
    236:         k              = ++sbuf1_j[0];
    237:         sbuf1_j[2*k]   = ctr_j;
    238:         sbuf1_j[2*k-1] = i;
    239:       }
    240:     }
    241:   }

    243:   /*  Now  post the sends */
    244:   PetscMalloc((nrqs+1)*sizeof(MPI_Request),&s_waits1);
    245:   for (i=0; i<nrqs; ++i) {
    246:     j = pa[i];
    247:     MPI_Isend(sbuf1[j],w1[2*j],MPIU_INT,j,tag0,comm,s_waits1+i);
    248:   }

    250:   /* Post recieves to capture the row_data from other procs */
    251:   PetscMalloc((nrqs+1)*sizeof(MPI_Request),&r_waits2);
    252:   PetscMalloc((nrqs+1)*sizeof(PetscScalar*),&rbuf2);
    253:   for (i=0; i<nrqs; i++) {
    254:     j        = pa[i];
    255:     count    = (w1[2*j] - (2*sbuf1[j][0] + 1))*N;
    256:     PetscMalloc((count+1)*sizeof(PetscScalar),&rbuf2[i]);
    257:     MPI_Irecv(rbuf2[i],count,MPIU_SCALAR,j,tag1,comm,r_waits2+i);
    258:   }

    260:   /* Receive messages(row_nos) and then, pack and send off the rowvalues
    261:      to the correct processors */

    263:   PetscMalloc((nrqr+1)*sizeof(MPI_Request),&s_waits2);
    264:   PetscMalloc((nrqr+1)*sizeof(MPI_Status),&r_status1);
    265:   PetscMalloc((nrqr+1)*sizeof(PetscScalar*),&sbuf2);
    266:
    267:   {
    268:     PetscScalar *sbuf2_i,*v_start;
    269:     PetscInt         s_proc;
    270:     for (i=0; i<nrqr; ++i) {
    271:       MPI_Waitany(nrqr,r_waits1,&idex,r_status1+i);
    272:       s_proc          = r_status1[i].MPI_SOURCE; /* send processor */
    273:       rbuf1_i         = rbuf1[idex]; /* Actual message from s_proc */
    274:       /* no of rows = end - start; since start is array idex[], 0idex, whel end
    275:          is length of the buffer - which is 1idex */
    276:       start           = 2*rbuf1_i[0] + 1;
    277:       MPI_Get_count(r_status1+i,MPIU_INT,&end);
    278:       /* allocate memory sufficinet to hold all the row values */
    279:       PetscMalloc((end-start)*N*sizeof(PetscScalar),&sbuf2[idex]);
    280:       sbuf2_i      = sbuf2[idex];
    281:       /* Now pack the data */
    282:       for (j=start; j<end; j++) {
    283:         row = rbuf1_i[j] - rstart;
    284:         v_start = a->v + row;
    285:         for (k=0; k<N; k++) {
    286:           sbuf2_i[0] = v_start[0];
    287:           sbuf2_i++; v_start += C->m;
    288:         }
    289:       }
    290:       /* Now send off the data */
    291:       MPI_Isend(sbuf2[idex],(end-start)*N,MPIU_SCALAR,s_proc,tag1,comm,s_waits2+i);
    292:     }
    293:   }
    294:   /* End Send-Recv of IS + row_numbers */
    295:   PetscFree(r_status1);
    296:   PetscFree(r_waits1);
    297:   PetscMalloc((nrqs+1)*sizeof(MPI_Status),&s_status1);
    298:   if (nrqs) {MPI_Waitall(nrqs,s_waits1,s_status1);}
    299:   PetscFree(s_status1);
    300:   PetscFree(s_waits1);

    302:   /* Create the submatrices */
    303:   if (scall == MAT_REUSE_MATRIX) {
    304:     for (i=0; i<ismax; i++) {
    305:       mat = (Mat_SeqDense *)(submats[i]->data);
    306:       if ((submats[i]->m != nrow[i]) || (submats[i]->n != ncol[i])) {
    307:         SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
    308:       }
    309:       PetscMemzero(mat->v,submats[i]->m*submats[i]->n*sizeof(PetscScalar));
    310:       submats[i]->factor = C->factor;
    311:     }
    312:   } else {
    313:     for (i=0; i<ismax; i++) {
    314:       MatCreate(PETSC_COMM_SELF,submats+i);
    315:       MatSetSizes(submats[i],nrow[i],ncol[i],nrow[i],ncol[i]);
    316:       MatSetType(submats[i],A->type_name);
    317:       MatSeqDenseSetPreallocation(submats[i],PETSC_NULL);
    318:     }
    319:   }
    320:
    321:   /* Assemble the matrices */
    322:   {
    323:     PetscInt         col;
    324:     PetscScalar *imat_v,*mat_v,*imat_vi,*mat_vi;
    325:
    326:     for (i=0; i<ismax; i++) {
    327:       mat       = (Mat_SeqDense*)submats[i]->data;
    328:       mat_v     = a->v;
    329:       imat_v    = mat->v;
    330:       irow_i    = irow[i];
    331:       m         = nrow[i];
    332:       for (j=0; j<m; j++) {
    333:         row      = irow_i[j] ;
    334:         proc     = rtable[row];
    335:         if (proc == rank) {
    336:           row      = row - rstart;
    337:           mat_vi   = mat_v + row;
    338:           imat_vi  = imat_v + j;
    339:           for (k=0; k<ncol[i]; k++) {
    340:             col = icol[i][k];
    341:             imat_vi[k*m] = mat_vi[col*C->m];
    342:           }
    343:         }
    344:       }
    345:     }
    346:   }

    348:   /* Create row map. This maps c->row to submat->row for each submat*/
    349:   /* this is a very expensive operation wrt memory usage */
    350:   len     = (1+ismax)*sizeof(PetscInt*)+ ismax*C->M*sizeof(PetscInt);
    351:   PetscMalloc(len,&rmap);
    352:   rmap[0] = (PetscInt*)(rmap + ismax);
    353:   PetscMemzero(rmap[0],ismax*C->M*sizeof(PetscInt));
    354:   for (i=1; i<ismax; i++) { rmap[i] = rmap[i-1] + C->M;}
    355:   for (i=0; i<ismax; i++) {
    356:     rmap_i = rmap[i];
    357:     irow_i = irow[i];
    358:     jmax   = nrow[i];
    359:     for (j=0; j<jmax; j++) {
    360:       rmap_i[irow_i[j]] = j;
    361:     }
    362:   }
    363:
    364:   /* Now Receive the row_values and assemble the rest of the matrix */
    365:   PetscMalloc((nrqs+1)*sizeof(MPI_Status),&r_status2);

    367:   {
    368:     PetscInt    is_max,tmp1,col,*sbuf1_i,is_sz;
    369:     PetscScalar *rbuf2_i,*imat_v,*imat_vi;
    370:
    371:     for (tmp1=0; tmp1<nrqs; tmp1++) { /* For each message */
    372:       MPI_Waitany(nrqs,r_waits2,&i,r_status2+tmp1);
    373:       /* Now dig out the corresponding sbuf1, which contains the IS data_structure */
    374:       sbuf1_i = sbuf1[pa[i]];
    375:       is_max  = sbuf1_i[0];
    376:       ct1     = 2*is_max+1;
    377:       rbuf2_i = rbuf2[i];
    378:       for (j=1; j<=is_max; j++) { /* For each IS belonging to the message */
    379:         is_no     = sbuf1_i[2*j-1];
    380:         is_sz     = sbuf1_i[2*j];
    381:         mat       = (Mat_SeqDense*)submats[is_no]->data;
    382:         imat_v    = mat->v;
    383:         rmap_i    = rmap[is_no];
    384:         m         = nrow[is_no];
    385:         for (k=0; k<is_sz; k++,rbuf2_i+=N) {  /* For each row */
    386:           row      = sbuf1_i[ct1]; ct1++;
    387:           row      = rmap_i[row];
    388:           imat_vi  = imat_v + row;
    389:           for (l=0; l<ncol[is_no]; l++) { /* For each col */
    390:             col = icol[is_no][l];
    391:             imat_vi[l*m] = rbuf2_i[col];
    392:           }
    393:         }
    394:       }
    395:     }
    396:   }
    397:   /* End Send-Recv of row_values */
    398:   PetscFree(r_status2);
    399:   PetscFree(r_waits2);
    400:   PetscMalloc((nrqr+1)*sizeof(MPI_Status),&s_status2);
    401:   if (nrqr) {MPI_Waitall(nrqr,s_waits2,s_status2);}
    402:   PetscFree(s_status2);
    403:   PetscFree(s_waits2);

    405:   /* Restore the indices */
    406:   for (i=0; i<ismax; i++) {
    407:     ISRestoreIndices(isrow[i],irow+i);
    408:     ISRestoreIndices(iscol[i],icol+i);
    409:   }

    411:   /* Destroy allocated memory */
    412:   PetscFree(irow);
    413:   PetscFree(w1);
    414:   PetscFree(pa);

    417:   for (i=0; i<nrqs; ++i) {
    418:     PetscFree(rbuf2[i]);
    419:   }
    420:   PetscFree(rbuf2);
    421:   PetscFree(sbuf1);
    422:   PetscFree(rbuf1);

    424:   for (i=0; i<nrqr; ++i) {
    425:     PetscFree(sbuf2[i]);
    426:   }

    428:   PetscFree(sbuf2);
    429:   PetscFree(rmap);

    431:   for (i=0; i<ismax; i++) {
    432:     MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);
    433:     MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);
    434:   }

    436:   return(0);
    437: }