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->cmap->N,&mdn->lvec);
21: /* Create temporary index set for building scatter gather */
22: ISCreateStride(((PetscObject)mat)->comm,mat->cmap->N,0,1,&from);
23: ISCreateStride(PETSC_COMM_SELF,mat->cmap->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: VecCreateMPIWithArray(((PetscObject)mat)->comm,mdn->nvec,mat->cmap->N,PETSC_NULL,&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->cmap->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,((PetscObject)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->cmap->N,rstart = C->rmap->rstart,count;
86: const PetscInt **irow,**icol,*irow_i;
87: PetscInt *nrow,*ncol,*w1,*w3,*w4,*rtable,start;
88: PetscInt **sbuf1,m,j,k,l,ct1,**rbuf1,row,proc;
89: PetscInt nrqs,msz,**ptr,*ctr,*pa,*tmp,bsz,nrqr;
90: PetscInt is_no,jmax,**rmap,*rmap_i;
91: PetscInt len,ctr_j,*sbuf1_j,*rbuf1_i;
92: MPI_Request *s_waits1,*r_waits1,*s_waits2,*r_waits2;
93: MPI_Status *r_status1,*r_status2,*s_status1,*s_status2;
94: MPI_Comm comm;
95: PetscScalar **rbuf2,**sbuf2;
96: PetscTruth sorted;
99: comm = ((PetscObject)C)->comm;
100: tag0 = ((PetscObject)C)->tag;
101: size = c->size;
102: rank = c->rank;
103: m = C->rmap->N;
104:
105: /* Get some new tags to keep the communication clean */
106: PetscObjectGetNewTag((PetscObject)C,&tag1);
108: /* Check if the col indices are sorted */
109: for (i=0; i<ismax; i++) {
110: ISSorted(isrow[i],&sorted);
111: if (!sorted) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"ISrow is not sorted");
112: ISSorted(iscol[i],&sorted);
113: if (!sorted) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"IScol is not sorted");
114: }
116: len = 2*ismax*(sizeof(PetscInt*)+sizeof(PetscInt)) + (m+1)*sizeof(PetscInt);
117: PetscMalloc(len,&irow);
118: icol = irow + ismax;
119: nrow = (PetscInt*)(icol + ismax);
120: ncol = nrow + ismax;
121: rtable = ncol + ismax;
123: for (i=0; i<ismax; i++) {
124: ISGetIndices(isrow[i],&irow[i]);
125: ISGetIndices(iscol[i],&icol[i]);
126: ISGetLocalSize(isrow[i],&nrow[i]);
127: ISGetLocalSize(iscol[i],&ncol[i]);
128: }
130: /* Create hash table for the mapping :row -> proc*/
131: for (i=0,j=0; i<size; i++) {
132: jmax = C->rmap->range[i+1];
133: for (; j<jmax; j++) {
134: rtable[j] = i;
135: }
136: }
138: /* evaluate communication - mesg to who,length of mesg, and buffer space
139: required. Based on this, buffers are allocated, and data copied into them*/
140: PetscMalloc(size*4*sizeof(PetscInt),&w1); /* mesg size */
141: w3 = w1 + 2*size; /* no of IS that needs to be sent to proc i */
142: w4 = w3 + size; /* temp work space used in determining w1, w3 */
143: PetscMemzero(w1,size*3*sizeof(PetscInt)); /* initialize work vector*/
144: for (i=0; i<ismax; i++) {
145: PetscMemzero(w4,size*sizeof(PetscInt)); /* initialize work vector*/
146: jmax = nrow[i];
147: irow_i = irow[i];
148: for (j=0; j<jmax; j++) {
149: row = irow_i[j];
150: proc = rtable[row];
151: w4[proc]++;
152: }
153: for (j=0; j<size; j++) {
154: if (w4[j]) { w1[2*j] += w4[j]; w3[j]++;}
155: }
156: }
157:
158: nrqs = 0; /* no of outgoing messages */
159: msz = 0; /* total mesg length (for all procs) */
160: w1[2*rank] = 0; /* no mesg sent to self */
161: w3[rank] = 0;
162: for (i=0; i<size; i++) {
163: if (w1[2*i]) { w1[2*i+1] = 1; nrqs++;} /* there exists a message to proc i */
164: }
165: PetscMalloc((nrqs+1)*sizeof(PetscInt),&pa); /*(proc -array)*/
166: for (i=0,j=0; i<size; i++) {
167: if (w1[2*i]) { pa[j] = i; j++; }
168: }
170: /* Each message would have a header = 1 + 2*(no of IS) + data */
171: for (i=0; i<nrqs; i++) {
172: j = pa[i];
173: w1[2*j] += w1[2*j+1] + 2* w3[j];
174: msz += w1[2*j];
175: }
176: /* Do a global reduction to determine how many messages to expect*/
177: PetscMaxSum(comm,w1,&bsz,&nrqr);
179: /* Allocate memory for recv buffers . Prob none if nrqr = 0 ???? */
180: len = (nrqr+1)*sizeof(PetscInt*) + nrqr*bsz*sizeof(PetscInt);
181: PetscMalloc(len,&rbuf1);
182: rbuf1[0] = (PetscInt*)(rbuf1 + nrqr);
183: for (i=1; i<nrqr; ++i) rbuf1[i] = rbuf1[i-1] + bsz;
184:
185: /* Post the receives */
186: PetscMalloc((nrqr+1)*sizeof(MPI_Request),&r_waits1);
187: for (i=0; i<nrqr; ++i) {
188: MPI_Irecv(rbuf1[i],bsz,MPIU_INT,MPI_ANY_SOURCE,tag0,comm,r_waits1+i);
189: }
191: /* Allocate Memory for outgoing messages */
192: len = 2*size*sizeof(PetscInt*) + 2*msz*sizeof(PetscInt)+ size*sizeof(PetscInt);
193: PetscMalloc(len,&sbuf1);
194: ptr = sbuf1 + size; /* Pointers to the data in outgoing buffers */
195: PetscMemzero(sbuf1,2*size*sizeof(PetscInt*));
196: /* allocate memory for outgoing data + buf to receive the first reply */
197: tmp = (PetscInt*)(ptr + size);
198: ctr = tmp + 2*msz;
200: {
201: PetscInt *iptr = tmp,ict = 0;
202: for (i=0; i<nrqs; i++) {
203: j = pa[i];
204: iptr += ict;
205: sbuf1[j] = iptr;
206: ict = w1[2*j];
207: }
208: }
210: /* Form the outgoing messages */
211: /* Initialize the header space */
212: for (i=0; i<nrqs; i++) {
213: j = pa[i];
214: sbuf1[j][0] = 0;
215: PetscMemzero(sbuf1[j]+1,2*w3[j]*sizeof(PetscInt));
216: ptr[j] = sbuf1[j] + 2*w3[j] + 1;
217: }
218:
219: /* Parse the isrow and copy data into outbuf */
220: for (i=0; i<ismax; i++) {
221: PetscMemzero(ctr,size*sizeof(PetscInt));
222: irow_i = irow[i];
223: jmax = nrow[i];
224: for (j=0; j<jmax; j++) { /* parse the indices of each IS */
225: row = irow_i[j];
226: proc = rtable[row];
227: if (proc != rank) { /* copy to the outgoing buf*/
228: ctr[proc]++;
229: *ptr[proc] = row;
230: ptr[proc]++;
231: }
232: }
233: /* Update the headers for the current IS */
234: for (j=0; j<size; j++) { /* Can Optimise this loop too */
235: if ((ctr_j = ctr[j])) {
236: sbuf1_j = sbuf1[j];
237: k = ++sbuf1_j[0];
238: sbuf1_j[2*k] = ctr_j;
239: sbuf1_j[2*k-1] = i;
240: }
241: }
242: }
244: /* Now post the sends */
245: PetscMalloc((nrqs+1)*sizeof(MPI_Request),&s_waits1);
246: for (i=0; i<nrqs; ++i) {
247: j = pa[i];
248: MPI_Isend(sbuf1[j],w1[2*j],MPIU_INT,j,tag0,comm,s_waits1+i);
249: }
251: /* Post recieves to capture the row_data from other procs */
252: PetscMalloc((nrqs+1)*sizeof(MPI_Request),&r_waits2);
253: PetscMalloc((nrqs+1)*sizeof(PetscScalar*),&rbuf2);
254: for (i=0; i<nrqs; i++) {
255: j = pa[i];
256: count = (w1[2*j] - (2*sbuf1[j][0] + 1))*N;
257: PetscMalloc((count+1)*sizeof(PetscScalar),&rbuf2[i]);
258: MPI_Irecv(rbuf2[i],count,MPIU_SCALAR,j,tag1,comm,r_waits2+i);
259: }
261: /* Receive messages(row_nos) and then, pack and send off the rowvalues
262: to the correct processors */
264: PetscMalloc((nrqr+1)*sizeof(MPI_Request),&s_waits2);
265: PetscMalloc((nrqr+1)*sizeof(MPI_Status),&r_status1);
266: PetscMalloc((nrqr+1)*sizeof(PetscScalar*),&sbuf2);
267:
268: {
269: PetscScalar *sbuf2_i,*v_start;
270: PetscInt s_proc;
271: for (i=0; i<nrqr; ++i) {
272: MPI_Waitany(nrqr,r_waits1,&idex,r_status1+i);
273: s_proc = r_status1[i].MPI_SOURCE; /* send processor */
274: rbuf1_i = rbuf1[idex]; /* Actual message from s_proc */
275: /* no of rows = end - start; since start is array idex[], 0idex, whel end
276: is length of the buffer - which is 1idex */
277: start = 2*rbuf1_i[0] + 1;
278: MPI_Get_count(r_status1+i,MPIU_INT,&end);
279: /* allocate memory sufficinet to hold all the row values */
280: PetscMalloc((end-start)*N*sizeof(PetscScalar),&sbuf2[idex]);
281: sbuf2_i = sbuf2[idex];
282: /* Now pack the data */
283: for (j=start; j<end; j++) {
284: row = rbuf1_i[j] - rstart;
285: v_start = a->v + row;
286: for (k=0; k<N; k++) {
287: sbuf2_i[0] = v_start[0];
288: sbuf2_i++; v_start += C->rmap->n;
289: }
290: }
291: /* Now send off the data */
292: MPI_Isend(sbuf2[idex],(end-start)*N,MPIU_SCALAR,s_proc,tag1,comm,s_waits2+i);
293: }
294: }
295: /* End Send-Recv of IS + row_numbers */
296: PetscFree(r_status1);
297: PetscFree(r_waits1);
298: PetscMalloc((nrqs+1)*sizeof(MPI_Status),&s_status1);
299: if (nrqs) {MPI_Waitall(nrqs,s_waits1,s_status1);}
300: PetscFree(s_status1);
301: PetscFree(s_waits1);
303: /* Create the submatrices */
304: if (scall == MAT_REUSE_MATRIX) {
305: for (i=0; i<ismax; i++) {
306: mat = (Mat_SeqDense *)(submats[i]->data);
307: if ((submats[i]->rmap->n != nrow[i]) || (submats[i]->cmap->n != ncol[i])) {
308: SETERRQ(PETSC_ERR_ARG_SIZ,"Cannot reuse matrix. wrong size");
309: }
310: PetscMemzero(mat->v,submats[i]->rmap->n*submats[i]->cmap->n*sizeof(PetscScalar));
311: submats[i]->factor = C->factor;
312: }
313: } else {
314: for (i=0; i<ismax; i++) {
315: MatCreate(PETSC_COMM_SELF,submats+i);
316: MatSetSizes(submats[i],nrow[i],ncol[i],nrow[i],ncol[i]);
317: MatSetType(submats[i],((PetscObject)A)->type_name);
318: MatSeqDenseSetPreallocation(submats[i],PETSC_NULL);
319: }
320: }
321:
322: /* Assemble the matrices */
323: {
324: PetscInt col;
325: PetscScalar *imat_v,*mat_v,*imat_vi,*mat_vi;
326:
327: for (i=0; i<ismax; i++) {
328: mat = (Mat_SeqDense*)submats[i]->data;
329: mat_v = a->v;
330: imat_v = mat->v;
331: irow_i = irow[i];
332: m = nrow[i];
333: for (j=0; j<m; j++) {
334: row = irow_i[j] ;
335: proc = rtable[row];
336: if (proc == rank) {
337: row = row - rstart;
338: mat_vi = mat_v + row;
339: imat_vi = imat_v + j;
340: for (k=0; k<ncol[i]; k++) {
341: col = icol[i][k];
342: imat_vi[k*m] = mat_vi[col*C->rmap->n];
343: }
344: }
345: }
346: }
347: }
349: /* Create row map-> This maps c->row to submat->row for each submat*/
350: /* this is a very expensive operation wrt memory usage */
351: len = (1+ismax)*sizeof(PetscInt*)+ ismax*C->rmap->N*sizeof(PetscInt);
352: PetscMalloc(len,&rmap);
353: rmap[0] = (PetscInt*)(rmap + ismax);
354: PetscMemzero(rmap[0],ismax*C->rmap->N*sizeof(PetscInt));
355: for (i=1; i<ismax; i++) { rmap[i] = rmap[i-1] + C->rmap->N;}
356: for (i=0; i<ismax; i++) {
357: rmap_i = rmap[i];
358: irow_i = irow[i];
359: jmax = nrow[i];
360: for (j=0; j<jmax; j++) {
361: rmap_i[irow_i[j]] = j;
362: }
363: }
364:
365: /* Now Receive the row_values and assemble the rest of the matrix */
366: PetscMalloc((nrqs+1)*sizeof(MPI_Status),&r_status2);
368: {
369: PetscInt is_max,tmp1,col,*sbuf1_i,is_sz;
370: PetscScalar *rbuf2_i,*imat_v,*imat_vi;
371:
372: for (tmp1=0; tmp1<nrqs; tmp1++) { /* For each message */
373: MPI_Waitany(nrqs,r_waits2,&i,r_status2+tmp1);
374: /* Now dig out the corresponding sbuf1, which contains the IS data_structure */
375: sbuf1_i = sbuf1[pa[i]];
376: is_max = sbuf1_i[0];
377: ct1 = 2*is_max+1;
378: rbuf2_i = rbuf2[i];
379: for (j=1; j<=is_max; j++) { /* For each IS belonging to the message */
380: is_no = sbuf1_i[2*j-1];
381: is_sz = sbuf1_i[2*j];
382: mat = (Mat_SeqDense*)submats[is_no]->data;
383: imat_v = mat->v;
384: rmap_i = rmap[is_no];
385: m = nrow[is_no];
386: for (k=0; k<is_sz; k++,rbuf2_i+=N) { /* For each row */
387: row = sbuf1_i[ct1]; ct1++;
388: row = rmap_i[row];
389: imat_vi = imat_v + row;
390: for (l=0; l<ncol[is_no]; l++) { /* For each col */
391: col = icol[is_no][l];
392: imat_vi[l*m] = rbuf2_i[col];
393: }
394: }
395: }
396: }
397: }
398: /* End Send-Recv of row_values */
399: PetscFree(r_status2);
400: PetscFree(r_waits2);
401: PetscMalloc((nrqr+1)*sizeof(MPI_Status),&s_status2);
402: if (nrqr) {MPI_Waitall(nrqr,s_waits2,s_status2);}
403: PetscFree(s_status2);
404: PetscFree(s_waits2);
406: /* Restore the indices */
407: for (i=0; i<ismax; i++) {
408: ISRestoreIndices(isrow[i],irow+i);
409: ISRestoreIndices(iscol[i],icol+i);
410: }
412: /* Destroy allocated memory */
413: PetscFree(irow);
414: PetscFree(w1);
415: PetscFree(pa);
418: for (i=0; i<nrqs; ++i) {
419: PetscFree(rbuf2[i]);
420: }
421: PetscFree(rbuf2);
422: PetscFree(sbuf1);
423: PetscFree(rbuf1);
425: for (i=0; i<nrqr; ++i) {
426: PetscFree(sbuf2[i]);
427: }
429: PetscFree(sbuf2);
430: PetscFree(rmap);
432: for (i=0; i<ismax; i++) {
433: MatAssemblyBegin(submats[i],MAT_FINAL_ASSEMBLY);
434: MatAssemblyEnd(submats[i],MAT_FINAL_ASSEMBLY);
435: }
437: return(0);
438: }