xref: /petsc/src/dm/impls/patch/patch.c (revision b61cff7c32c5753eb5e5f3221001c85a98a4c1be)
1 #include <petsc/private/dmpatchimpl.h> /*I      "petscdmpatch.h"   I*/
2 #include <petscdmda.h>
3 #include <petscsf.h>
4 
5 /*
6 Solver loop to update \tau:
7 
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 */
20 
21 /*@
22   DMPatchZoom - Create patches of a `DMDA` on subsets of processes, indicated by `commz`
23 
24   Collective
25 
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
31 
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
36 
37   Level: intermediate
38 
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;
54 
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));
60 
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;
71 
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   }
95 
96   /* Create SF for restricted map */
97   PetscCall(DMCreateGlobalVector(dm, &X));
98   PetscCall(VecGetOwnershipRanges(X, &ranges));
99 
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;
106 
107   PetscCall(DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc));
108   PetscCall(ISGetIndices(is, &indices));
109 
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;
124 
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));
129 
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));
142 
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;
151 
152     PetscCall(DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc));
153     PetscCall(ISGetIndices(is, &indices));
154 
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;
161 
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   }
176 
177   PetscCall(VecDestroy(&X));
178   PetscCall(PetscFree2(localPoints, remotePoints));
179   PetscFunctionReturn(PETSC_SUCCESS);
180 }
181 
182 typedef enum {
183   PATCH_COMM_TYPE_WORLD = 0,
184   PATCH_COMM_TYPE_SELF  = 1
185 } PatchCommType;
186 
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;
197 
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);
214 
215   gridRank.i = rank % l;
216   gridRank.j = rank / l % m;
217   gridRank.k = rank / (l * m) % n;
218 
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));
229 
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
239 
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;
256 
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 */
303 
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 }
313 
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;
319 
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 }
331 
332 PetscErrorCode DMView_Patch(DM dm, PetscViewer viewer)
333 {
334   PetscBool iascii, isbinary;
335 
336   PetscFunctionBegin;
337   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
338   PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 2);
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 }
344 
345 PetscErrorCode DMDestroy_Patch(DM dm)
346 {
347   DM_Patch *mesh = (DM_Patch *)dm->data;
348 
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 }
356 
357 PetscErrorCode DMSetUp_Patch(DM dm)
358 {
359   DM_Patch *mesh = (DM_Patch *)dm->data;
360 
361   PetscFunctionBegin;
362   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
363   PetscCall(DMSetUp(mesh->dmCoarse));
364   PetscFunctionReturn(PETSC_SUCCESS);
365 }
366 
367 PetscErrorCode DMCreateGlobalVector_Patch(DM dm, Vec *g)
368 {
369   DM_Patch *mesh = (DM_Patch *)dm->data;
370 
371   PetscFunctionBegin;
372   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
373   PetscCall(DMCreateGlobalVector(mesh->dmCoarse, g));
374   PetscFunctionReturn(PETSC_SUCCESS);
375 }
376 
377 PetscErrorCode DMCreateLocalVector_Patch(DM dm, Vec *l)
378 {
379   DM_Patch *mesh = (DM_Patch *)dm->data;
380 
381   PetscFunctionBegin;
382   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
383   PetscCall(DMCreateLocalVector(mesh->dmCoarse, l));
384   PetscFunctionReturn(PETSC_SUCCESS);
385 }
386 
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 }
391 
392 PetscErrorCode DMPatchGetCoarse(DM dm, DM *dmCoarse)
393 {
394   DM_Patch *mesh = (DM_Patch *)dm->data;
395 
396   PetscFunctionBegin;
397   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
398   *dmCoarse = mesh->dmCoarse;
399   PetscFunctionReturn(PETSC_SUCCESS);
400 }
401 
402 PetscErrorCode DMPatchGetPatchSize(DM dm, MatStencil *patchSize)
403 {
404   DM_Patch *mesh = (DM_Patch *)dm->data;
405 
406   PetscFunctionBegin;
407   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
408   PetscAssertPointer(patchSize, 2);
409   *patchSize = mesh->patchSize;
410   PetscFunctionReturn(PETSC_SUCCESS);
411 }
412 
413 PetscErrorCode DMPatchSetPatchSize(DM dm, MatStencil patchSize)
414 {
415   DM_Patch *mesh = (DM_Patch *)dm->data;
416 
417   PetscFunctionBegin;
418   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
419   mesh->patchSize = patchSize;
420   PetscFunctionReturn(PETSC_SUCCESS);
421 }
422 
423 PetscErrorCode DMPatchGetCommSize(DM dm, MatStencil *commSize)
424 {
425   DM_Patch *mesh = (DM_Patch *)dm->data;
426 
427   PetscFunctionBegin;
428   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
429   PetscAssertPointer(commSize, 2);
430   *commSize = mesh->commSize;
431   PetscFunctionReturn(PETSC_SUCCESS);
432 }
433 
434 PetscErrorCode DMPatchSetCommSize(DM dm, MatStencil commSize)
435 {
436   DM_Patch *mesh = (DM_Patch *)dm->data;
437 
438   PetscFunctionBegin;
439   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
440   mesh->commSize = commSize;
441   PetscFunctionReturn(PETSC_SUCCESS);
442 }
443