Actual source code: patch.c

  1: #include <petsc/private/dmpatchimpl.h>
  2: #include <petscdmda.h>
  3: #include <petscsf.h>

  5: /*
  6: Solver loop to update \tau:

  8:   DMZoom(dmc, &dmz)
  9:   DMRefine(dmz, &dmf),
 10:   Scatter Xcoarse -> Xzoom,
 11:   Interpolate Xzoom -> Xfine (note that this may be on subcomms),
 12:   Smooth Xfine using two-step smoother
 13:     normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine
 14:   Compute residual Rfine
 15:   Restrict Rfine to Rzoom_restricted
 16:   Scatter Rzoom_restricted -> Rcoarse_restricted
 17:   Compute global residual Rcoarse
 18:   TauCoarse = Rcoarse - Rcoarse_restricted
 19: */

 21: /*@
 22:   DMPatchZoom - Create patches of a `DMDA` on subsets of processes, indicated by `commz`

 24:   Collective

 26:   Input Parameters:
 27: + dm    - the `DM`
 28: . lower - the lower left corner of the requested patch
 29: . upper - the upper right corner of the requested patch
 30: - commz - the new communicator for the patch, `MPI_COMM_NULL` indicates that the given rank will not own a patch

 32:   Output Parameters:
 33: + dmz  - the patch `DM`
 34: . sfz  - the `PetscSF` mapping the patch+halo to the zoomed version (optional)
 35: - sfzr - the `PetscSF` mapping the patch to the restricted zoomed version

 37:   Level: intermediate

 39: .seealso: `DMPatchSolve()`, `DMDACreatePatchIS()`
 40: @*/
 41: PetscErrorCode DMPatchZoom(DM dm, MatStencil lower, MatStencil upper, MPI_Comm commz, DM *dmz, PetscSF *sfz, PetscSF *sfzr)
 42: {
 43:   DMDAStencilType st;
 44:   MatStencil      blower, bupper, loclower, locupper;
 45:   IS              is;
 46:   const PetscInt *ranges, *indices;
 47:   PetscInt       *localPoints  = NULL;
 48:   PetscSFNode    *remotePoints = NULL;
 49:   PetscInt        dim, dof;
 50:   PetscInt        M, N, P, rM, rN, rP, halo = 1, sxb, syb, szb, sxr, syr, szr, exr, eyr, ezr, mxb, myb, mzb, i, j, k, l, q;
 51:   PetscMPIInt     size;
 52:   PetscBool       patchis_offproc = PETSC_TRUE;
 53:   Vec             X;

 55:   PetscFunctionBegin;
 56:   if (!sfz) halo = 0;
 57:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
 58:   /* Create patch DM */
 59:   PetscCall(DMDAGetInfo(dm, &dim, &M, &N, &P, NULL, NULL, NULL, &dof, NULL, NULL, NULL, NULL, &st));

 61:   /* Get piece for rank r, expanded by halo */
 62:   bupper.i = PetscMin(M, upper.i + halo);
 63:   blower.i = PetscMax(lower.i - halo, 0);
 64:   bupper.j = PetscMin(N, upper.j + halo);
 65:   blower.j = PetscMax(lower.j - halo, 0);
 66:   bupper.k = PetscMin(P, upper.k + halo);
 67:   blower.k = PetscMax(lower.k - halo, 0);
 68:   rM       = bupper.i - blower.i;
 69:   rN       = bupper.j - blower.j;
 70:   rP       = bupper.k - blower.k;

 72:   if (commz != MPI_COMM_NULL) {
 73:     PetscCall(DMDACreate(commz, dmz));
 74:     PetscCall(DMSetDimension(*dmz, dim));
 75:     PetscCall(DMDASetSizes(*dmz, rM, rN, rP));
 76:     PetscCall(DMDASetNumProcs(*dmz, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE));
 77:     PetscCall(DMDASetBoundaryType(*dmz, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE));
 78:     PetscCall(DMDASetDof(*dmz, dof));
 79:     PetscCall(DMDASetStencilType(*dmz, st));
 80:     PetscCall(DMDASetStencilWidth(*dmz, 0));
 81:     PetscCall(DMDASetOwnershipRanges(*dmz, NULL, NULL, NULL));
 82:     PetscCall(DMSetFromOptions(*dmz));
 83:     PetscCall(DMSetUp(*dmz));
 84:     PetscCall(DMDAGetCorners(*dmz, &sxb, &syb, &szb, &mxb, &myb, &mzb));
 85:     sxr = PetscMax(sxb, lower.i - blower.i);
 86:     syr = PetscMax(syb, lower.j - blower.j);
 87:     szr = PetscMax(szb, lower.k - blower.k);
 88:     exr = PetscMin(sxb + mxb, upper.i - blower.i);
 89:     eyr = PetscMin(syb + myb, upper.j - blower.j);
 90:     ezr = PetscMin(szb + mzb, upper.k - blower.k);
 91:     PetscCall(PetscMalloc2(dof * rM * rN * PetscMax(rP, 1), &localPoints, dof * rM * rN * PetscMax(rP, 1), &remotePoints));
 92:   } else {
 93:     sxr = syr = szr = exr = eyr = ezr = sxb = syb = szb = mxb = myb = mzb = 0;
 94:   }

 96:   /* Create SF for restricted map */
 97:   PetscCall(DMCreateGlobalVector(dm, &X));
 98:   PetscCall(VecGetOwnershipRanges(X, &ranges));

100:   loclower.i = blower.i + sxr;
101:   locupper.i = blower.i + exr;
102:   loclower.j = blower.j + syr;
103:   locupper.j = blower.j + eyr;
104:   loclower.k = blower.k + szr;
105:   locupper.k = blower.k + ezr;

107:   PetscCall(DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc));
108:   PetscCall(ISGetIndices(is, &indices));

110:   if (dim < 3) {
111:     mzb = 1;
112:     ezr = 1;
113:   }
114:   q = 0;
115:   for (k = szb; k < szb + mzb; ++k) {
116:     if ((k < szr) || (k >= ezr)) continue;
117:     for (j = syb; j < syb + myb; ++j) {
118:       if ((j < syr) || (j >= eyr)) continue;
119:       for (i = sxb; i < sxb + mxb; ++i) {
120:         for (l = 0; l < dof; l++) {
121:           const PetscInt lp = l + dof * (((k - szb) * rN + (j - syb)) * rM + i - sxb);
122:           PetscMPIInt    r;
123:           PetscInt       ir;

125:           if ((i < sxr) || (i >= exr)) continue;
126:           localPoints[q] = lp;
127:           PetscCall(PetscFindInt(indices[q], size + 1, ranges, &ir));
128:           PetscCall(PetscMPIIntCast(ir, &r));

130:           remotePoints[q].rank  = r < 0 ? -(r + 1) - 1 : r;
131:           remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
132:           ++q;
133:         }
134:       }
135:     }
136:   }
137:   PetscCall(ISRestoreIndices(is, &indices));
138:   PetscCall(ISDestroy(&is));
139:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), sfzr));
140:   PetscCall(PetscObjectSetName((PetscObject)*sfzr, "Restricted Map"));
141:   PetscCall(PetscSFSetGraph(*sfzr, dof * M * N * P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES));

143:   if (sfz) {
144:     /* Create SF for buffered map */
145:     loclower.i = blower.i + sxb;
146:     locupper.i = blower.i + sxb + mxb;
147:     loclower.j = blower.j + syb;
148:     locupper.j = blower.j + syb + myb;
149:     loclower.k = blower.k + szb;
150:     locupper.k = blower.k + szb + mzb;

152:     PetscCall(DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc));
153:     PetscCall(ISGetIndices(is, &indices));

155:     q = 0;
156:     for (k = szb; k < szb + mzb; ++k) {
157:       for (j = syb; j < syb + myb; ++j) {
158:         for (i = sxb; i < sxb + mxb; ++i, ++q) {
159:           PetscInt    ir;
160:           PetscMPIInt r;

162:           localPoints[q] = q;
163:           PetscCall(PetscFindInt(indices[q], size + 1, ranges, &ir));
164:           PetscCall(PetscMPIIntCast(ir, &r));
165:           remotePoints[q].rank  = r < 0 ? -(r + 1) - 1 : r;
166:           remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
167:         }
168:       }
169:     }
170:     PetscCall(ISRestoreIndices(is, &indices));
171:     PetscCall(ISDestroy(&is));
172:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), sfz));
173:     PetscCall(PetscObjectSetName((PetscObject)*sfz, "Buffered Map"));
174:     PetscCall(PetscSFSetGraph(*sfz, M * N * P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES));
175:   }

177:   PetscCall(VecDestroy(&X));
178:   PetscCall(PetscFree2(localPoints, remotePoints));
179:   PetscFunctionReturn(PETSC_SUCCESS);
180: }

182: typedef enum {
183:   PATCH_COMM_TYPE_WORLD = 0,
184:   PATCH_COMM_TYPE_SELF  = 1
185: } PatchCommType;

187: PetscErrorCode DMPatchSolve(DM dm)
188: {
189:   MPI_Comm    comm, commz;
190:   DM          dmc;
191:   PetscSF     sfz, sfzr;
192:   Vec         XC;
193:   MatStencil  patchSize, commSize, gridRank, lower, upper;
194:   PetscInt    M, N, P, i, j, k, l, m, n, p = 0;
195:   PetscMPIInt rank, size;
196:   PetscInt    debug = 0;

198:   PetscFunctionBegin;
199:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
200:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
201:   PetscCallMPI(MPI_Comm_size(comm, &size));
202:   PetscCall(DMPatchGetCoarse(dm, &dmc));
203:   PetscCall(DMPatchGetPatchSize(dm, &patchSize));
204:   PetscCall(DMPatchGetCommSize(dm, &commSize));
205:   PetscCall(DMPatchGetCommSize(dm, &commSize));
206:   PetscCall(DMGetGlobalVector(dmc, &XC));
207:   PetscCall(DMDAGetInfo(dmc, NULL, &M, &N, &P, &l, &m, &n, NULL, NULL, NULL, NULL, NULL, NULL));
208:   M = PetscMax(M, 1);
209:   l = PetscMax(l, 1);
210:   N = PetscMax(N, 1);
211:   m = PetscMax(m, 1);
212:   P = PetscMax(P, 1);
213:   n = PetscMax(n, 1);

215:   gridRank.i = rank % l;
216:   gridRank.j = rank / l % m;
217:   gridRank.k = rank / (l * m) % n;

219:   if (commSize.i * commSize.j * commSize.k == size || commSize.i * commSize.j * commSize.k == 0) {
220:     commSize.i = l;
221:     commSize.j = m;
222:     commSize.k = n;
223:     commz      = comm;
224:   } else if (commSize.i * commSize.j * commSize.k == 1) {
225:     commz = PETSC_COMM_SELF;
226:   } else {
227:     const PetscMPIInt newComm = (PetscMPIInt)(((gridRank.k / commSize.k) * (m / commSize.j) + gridRank.j / commSize.j) * (l / commSize.i) + (gridRank.i / commSize.i));
228:     const PetscMPIInt newRank = (PetscMPIInt)(((gridRank.k % commSize.k) * commSize.j + gridRank.j % commSize.j) * commSize.i + (gridRank.i % commSize.i));

230:     PetscCallMPI(MPI_Comm_split(comm, newComm, newRank, &commz));
231:     if (debug) PetscCall(PetscPrintf(PETSC_COMM_SELF, "Rank %d color %d key %d commz %p\n", rank, newComm, newRank, (void *)(MPI_Aint)commz));
232:   }
233:   /*
234:    Assumptions:
235:      - patchSize divides gridSize
236:      - commSize divides gridSize
237:      - commSize divides l,m,n
238:    Ignore multiple patches per rank for now

240:    Multiple ranks per patch:
241:      - l,m,n divides patchSize
242:      - commSize divides patchSize
243:    */
244:   for (k = 0; k < P; k += PetscMax(patchSize.k, 1)) {
245:     for (j = 0; j < N; j += PetscMax(patchSize.j, 1)) {
246:       for (i = 0; i < M; i += PetscMax(patchSize.i, 1), ++p) {
247:         MPI_Comm commp = MPI_COMM_NULL;
248:         DM       dmz   = NULL;
249: #if 0
250:         DM          dmf     = NULL;
251:         Mat         interpz = NULL;
252: #endif
253:         Vec          XZ      = NULL;
254:         PetscScalar *xcarray = NULL;
255:         PetscScalar *xzarray = NULL;

257:         if ((gridRank.k / commSize.k == p / (l / commSize.i * m / commSize.j) % n / commSize.k) && (gridRank.j / commSize.j == p / (l / commSize.i) % m / commSize.j) && (gridRank.i / commSize.i == p % l / commSize.i)) {
258:           if (debug) PetscCall(PetscPrintf(PETSC_COMM_SELF, "Rank %d is accepting Patch %" PetscInt_FMT "\n", rank, p));
259:           commp = commz;
260:         }
261:         /* Zoom to coarse patch */
262:         lower.i = i;
263:         lower.j = j;
264:         lower.k = k;
265:         upper.i = i + patchSize.i;
266:         upper.j = j + patchSize.j;
267:         upper.k = k + patchSize.k;
268:         PetscCall(DMPatchZoom(dmc, lower, upper, commp, &dmz, &sfz, &sfzr));
269:         lower.c = 0; /* initialize member, otherwise compiler issues warnings */
270:         upper.c = 0; /* initialize member, otherwise compiler issues warnings */
271:         if (debug)
272:           PetscCall(PetscPrintf(comm, "Patch %" PetscInt_FMT ": (%" PetscInt_FMT ", %" PetscInt_FMT ", %" PetscInt_FMT ")--(%" PetscInt_FMT ", %" PetscInt_FMT ", %" PetscInt_FMT ")\n", p, lower.i, lower.j, lower.k, upper.i, upper.j, upper.k));
273:         if (dmz) PetscCall(DMView(dmz, PETSC_VIEWER_STDOUT_(commz)));
274:         PetscCall(PetscSFView(sfz, PETSC_VIEWER_STDOUT_(comm)));
275:         PetscCall(PetscSFView(sfzr, PETSC_VIEWER_STDOUT_(comm)));
276:         /* Scatter Xcoarse -> Xzoom */
277:         if (dmz) PetscCall(DMGetGlobalVector(dmz, &XZ));
278:         if (XZ) PetscCall(VecGetArray(XZ, &xzarray));
279:         PetscCall(VecGetArray(XC, &xcarray));
280:         PetscCall(PetscSFBcastBegin(sfz, MPIU_SCALAR, xcarray, xzarray, MPI_REPLACE));
281:         PetscCall(PetscSFBcastEnd(sfz, MPIU_SCALAR, xcarray, xzarray, MPI_REPLACE));
282:         PetscCall(VecRestoreArray(XC, &xcarray));
283:         if (XZ) PetscCall(VecRestoreArray(XZ, &xzarray));
284: #if 0
285:         /* Interpolate Xzoom -> Xfine, note that this may be on subcomms */
286:         PetscCall(DMRefine(dmz, MPI_COMM_NULL, &dmf));
287:         PetscCall(DMCreateInterpolation(dmz, dmf, &interpz, NULL));
288:         PetscCall(DMInterpolate(dmz, interpz, dmf));
289:         /* Smooth Xfine using two-step smoother, normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine */
290:         /* Compute residual Rfine */
291:         /* Restrict Rfine to Rzoom_restricted */
292: #endif
293:         /* Scatter Rzoom_restricted -> Rcoarse_restricted */
294:         if (XZ) PetscCall(VecGetArray(XZ, &xzarray));
295:         PetscCall(VecGetArray(XC, &xcarray));
296:         PetscCall(PetscSFReduceBegin(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM));
297:         PetscCall(PetscSFReduceEnd(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM));
298:         PetscCall(VecRestoreArray(XC, &xcarray));
299:         if (XZ) PetscCall(VecRestoreArray(XZ, &xzarray));
300:         if (dmz) PetscCall(DMRestoreGlobalVector(dmz, &XZ));
301:         /* Compute global residual Rcoarse */
302:         /* TauCoarse = Rcoarse - Rcoarse_restricted */

304:         PetscCall(PetscSFDestroy(&sfz));
305:         PetscCall(PetscSFDestroy(&sfzr));
306:         PetscCall(DMDestroy(&dmz));
307:       }
308:     }
309:   }
310:   PetscCall(DMRestoreGlobalVector(dmc, &XC));
311:   PetscFunctionReturn(PETSC_SUCCESS);
312: }

314: static PetscErrorCode DMPatchView_ASCII(DM dm, PetscViewer viewer)
315: {
316:   DM_Patch         *mesh = (DM_Patch *)dm->data;
317:   PetscViewerFormat format;
318:   const char       *name;

320:   PetscFunctionBegin;
321:   PetscCall(PetscViewerGetFormat(viewer, &format));
322:   /* if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) */
323:   PetscCall(PetscObjectGetName((PetscObject)dm, &name));
324:   PetscCall(PetscViewerASCIIPrintf(viewer, "Patch DM %s\n", name));
325:   PetscCall(PetscViewerASCIIPushTab(viewer));
326:   PetscCall(PetscViewerASCIIPrintf(viewer, "Coarse DM\n"));
327:   PetscCall(DMView(mesh->dmCoarse, viewer));
328:   PetscCall(PetscViewerASCIIPopTab(viewer));
329:   PetscFunctionReturn(PETSC_SUCCESS);
330: }

332: PetscErrorCode DMView_Patch(DM dm, PetscViewer viewer)
333: {
334:   PetscBool iascii, isbinary;

336:   PetscFunctionBegin;
339:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
340:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
341:   if (iascii) PetscCall(DMPatchView_ASCII(dm, viewer));
342:   PetscFunctionReturn(PETSC_SUCCESS);
343: }

345: PetscErrorCode DMDestroy_Patch(DM dm)
346: {
347:   DM_Patch *mesh = (DM_Patch *)dm->data;

349:   PetscFunctionBegin;
350:   if (--mesh->refct > 0) PetscFunctionReturn(PETSC_SUCCESS);
351:   PetscCall(DMDestroy(&mesh->dmCoarse));
352:   /* This was originally freed in DMDestroy(), but that prevents reference counting of backend objects */
353:   PetscCall(PetscFree(mesh));
354:   PetscFunctionReturn(PETSC_SUCCESS);
355: }

357: PetscErrorCode DMSetUp_Patch(DM dm)
358: {
359:   DM_Patch *mesh = (DM_Patch *)dm->data;

361:   PetscFunctionBegin;
363:   PetscCall(DMSetUp(mesh->dmCoarse));
364:   PetscFunctionReturn(PETSC_SUCCESS);
365: }

367: PetscErrorCode DMCreateGlobalVector_Patch(DM dm, Vec *g)
368: {
369:   DM_Patch *mesh = (DM_Patch *)dm->data;

371:   PetscFunctionBegin;
373:   PetscCall(DMCreateGlobalVector(mesh->dmCoarse, g));
374:   PetscFunctionReturn(PETSC_SUCCESS);
375: }

377: PetscErrorCode DMCreateLocalVector_Patch(DM dm, Vec *l)
378: {
379:   DM_Patch *mesh = (DM_Patch *)dm->data;

381:   PetscFunctionBegin;
383:   PetscCall(DMCreateLocalVector(mesh->dmCoarse, l));
384:   PetscFunctionReturn(PETSC_SUCCESS);
385: }

387: PetscErrorCode DMCreateSubDM_Patch(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
388: {
389:   SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Tell me to code this");
390: }

392: PetscErrorCode DMPatchGetCoarse(DM dm, DM *dmCoarse)
393: {
394:   DM_Patch *mesh = (DM_Patch *)dm->data;

396:   PetscFunctionBegin;
398:   *dmCoarse = mesh->dmCoarse;
399:   PetscFunctionReturn(PETSC_SUCCESS);
400: }

402: PetscErrorCode DMPatchGetPatchSize(DM dm, MatStencil *patchSize)
403: {
404:   DM_Patch *mesh = (DM_Patch *)dm->data;

406:   PetscFunctionBegin;
408:   PetscAssertPointer(patchSize, 2);
409:   *patchSize = mesh->patchSize;
410:   PetscFunctionReturn(PETSC_SUCCESS);
411: }

413: PetscErrorCode DMPatchSetPatchSize(DM dm, MatStencil patchSize)
414: {
415:   DM_Patch *mesh = (DM_Patch *)dm->data;

417:   PetscFunctionBegin;
419:   mesh->patchSize = patchSize;
420:   PetscFunctionReturn(PETSC_SUCCESS);
421: }

423: PetscErrorCode DMPatchGetCommSize(DM dm, MatStencil *commSize)
424: {
425:   DM_Patch *mesh = (DM_Patch *)dm->data;

427:   PetscFunctionBegin;
429:   PetscAssertPointer(commSize, 2);
430:   *commSize = mesh->commSize;
431:   PetscFunctionReturn(PETSC_SUCCESS);
432: }

434: PetscErrorCode DMPatchSetCommSize(DM dm, MatStencil commSize)
435: {
436:   DM_Patch *mesh = (DM_Patch *)dm->data;

438:   PetscFunctionBegin;
440:   mesh->commSize = commSize;
441:   PetscFunctionReturn(PETSC_SUCCESS);
442: }