xref: /petsc/src/dm/impls/patch/patch.c (revision b698fc57f0bea7237255b29c1b77df0acc362ffd)
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 a version of the coarse patch (identified by rank) with halo on communicator commz
23 
24   Collective on dm
25 
26   Input Parameters:
27   + dm - the DM
28   . rank - the rank which holds the given patch
29   - commz - the new communicator for the patch
30 
31   Output Parameters:
32   + dmz  - the patch DM
33   . sfz  - the PetscSF mapping the patch+halo to the zoomed version
34   . sfzr - the PetscSF mapping the patch to the restricted zoomed version
35 
36   Level: intermediate
37 
38   Note: All processes in commz should have the same rank (could autosplit comm)
39 
40 .seealso: DMPatchSolve()
41 */
42 PetscErrorCode DMPatchZoom(DM dm, Vec X, MatStencil lower, MatStencil upper, MPI_Comm commz, DM *dmz, PetscSF *sfz, PetscSF *sfzr)
43 {
44   DMDAStencilType st;
45   MatStencil      blower, bupper, loclower, locupper;
46   IS              is;
47   const PetscInt  *ranges, *indices;
48   PetscInt        *localPoints  = NULL;
49   PetscSFNode     *remotePoints = NULL;
50   PetscInt        dim, dof;
51   PetscInt        M, N, P, rM, rN, rP, halo = 1, sxb, syb, szb, sxr, syr, szr, exr, eyr, ezr, mxb, myb, mzb, i, j, k, q;
52   PetscMPIInt     size;
53   PetscBool       patchis_offproc = PETSC_TRUE;
54   PetscErrorCode  ierr;
55 
56   PetscFunctionBegin;
57   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size);CHKERRQ(ierr);
58   /* Create patch DM */
59   ierr = DMDAGetInfo(dm, &dim, &M, &N, &P, NULL,NULL,NULL, &dof, NULL,NULL,NULL,NULL, &st);CHKERRQ(ierr);
60 
61   /* Get piece for rank r, expanded by halo */
62   bupper.i = PetscMin(M, upper.i + halo); blower.i = PetscMax(lower.i - halo, 0);
63   bupper.j = PetscMin(N, upper.j + halo); blower.j = PetscMax(lower.j - halo, 0);
64   bupper.k = PetscMin(P, upper.k + halo); blower.k = PetscMax(lower.k - halo, 0);
65   rM       = bupper.i - blower.i;
66   rN       = bupper.j - blower.j;
67   rP       = bupper.k - blower.k;
68 
69   if (commz != MPI_COMM_NULL) {
70     ierr = DMDACreate(commz, dmz);CHKERRQ(ierr);
71     ierr = DMSetDimension(*dmz, dim);CHKERRQ(ierr);
72     ierr = DMDASetSizes(*dmz, rM, rN, rP);CHKERRQ(ierr);
73     ierr = DMDASetNumProcs(*dmz, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE);CHKERRQ(ierr);
74     ierr = DMDASetBoundaryType(*dmz, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);CHKERRQ(ierr);
75     ierr = DMDASetDof(*dmz, dof);CHKERRQ(ierr);
76     ierr = DMDASetStencilType(*dmz, st);CHKERRQ(ierr);
77     ierr = DMDASetStencilWidth(*dmz, 0);CHKERRQ(ierr);
78     ierr = DMDASetOwnershipRanges(*dmz, NULL, NULL, NULL);CHKERRQ(ierr);
79     ierr = DMSetFromOptions(*dmz);CHKERRQ(ierr);
80     ierr = DMSetUp(*dmz);CHKERRQ(ierr);
81     ierr = DMDAGetCorners(*dmz, &sxb, &syb, &szb, &mxb, &myb, &mzb);CHKERRQ(ierr);
82     sxr  = PetscMax(sxb,     lower.i - blower.i);
83     syr  = PetscMax(syb,     lower.j - blower.j);
84     szr  = PetscMax(szb,     lower.k - blower.k);
85     exr  = PetscMin(sxb+mxb, upper.i - blower.i);
86     eyr  = PetscMin(syb+myb, upper.j - blower.j);
87     ezr  = PetscMin(szb+mzb, upper.k - blower.k);
88     ierr = PetscMalloc2(rM*rN*rP,&localPoints,rM*rN*rP,&remotePoints);CHKERRQ(ierr);
89   } else {
90     sxr = syr = szr = exr = eyr = ezr = sxb = syb = szb = mxb = myb = mzb = 0;
91   }
92 
93   /* Create SF for restricted map */
94   ierr = VecGetOwnershipRanges(X,&ranges);CHKERRQ(ierr);
95 
96   loclower.i = blower.i + sxr; locupper.i = blower.i + exr;
97   loclower.j = blower.j + syr; locupper.j = blower.j + eyr;
98   loclower.k = blower.k + szr; locupper.k = blower.k + ezr;
99 
100   ierr = DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc);CHKERRQ(ierr);
101   ierr = ISGetIndices(is, &indices);CHKERRQ(ierr);
102 
103   q = 0;
104   for (k = szb; k < szb+mzb; ++k) {
105     if ((k < szr) || (k >= ezr)) continue;
106     for (j = syb; j < syb+myb; ++j) {
107       if ((j < syr) || (j >= eyr)) continue;
108       for (i = sxb; i < sxb+mxb; ++i) {
109         const PetscInt lp = ((k-szb)*rN + (j-syb))*rM + i-sxb;
110         PetscInt       r;
111 
112         if ((i < sxr) || (i >= exr)) continue;
113         localPoints[q]        = lp;
114         ierr = PetscFindInt(indices[q], size+1, ranges, &r);CHKERRQ(ierr);
115 
116         remotePoints[q].rank  = r < 0 ? -(r+1) - 1 : r;
117         remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
118         ++q;
119       }
120     }
121   }
122   ierr = ISRestoreIndices(is, &indices);CHKERRQ(ierr);
123   ierr = ISDestroy(&is);CHKERRQ(ierr);
124   ierr = PetscSFCreate(PetscObjectComm((PetscObject)dm), sfzr);CHKERRQ(ierr);
125   ierr = PetscObjectSetName((PetscObject) *sfzr, "Restricted Map");CHKERRQ(ierr);
126   ierr = PetscSFSetGraph(*sfzr, M*N*P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES);CHKERRQ(ierr);
127 
128   /* Create SF for buffered map */
129   loclower.i = blower.i + sxb; locupper.i = blower.i + sxb+mxb;
130   loclower.j = blower.j + syb; locupper.j = blower.j + syb+myb;
131   loclower.k = blower.k + szb; locupper.k = blower.k + szb+mzb;
132 
133   ierr = DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc);CHKERRQ(ierr);
134   ierr = ISGetIndices(is, &indices);CHKERRQ(ierr);
135 
136   q = 0;
137   for (k = szb; k < szb+mzb; ++k) {
138     for (j = syb; j < syb+myb; ++j) {
139       for (i = sxb; i < sxb+mxb; ++i, ++q) {
140         PetscInt r;
141 
142         localPoints[q]        = q;
143         ierr = PetscFindInt(indices[q], size+1, ranges, &r);CHKERRQ(ierr);
144         remotePoints[q].rank  = r < 0 ? -(r+1) - 1 : r;
145         remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
146       }
147     }
148   }
149   ierr = ISRestoreIndices(is, &indices);CHKERRQ(ierr);
150   ierr = ISDestroy(&is);CHKERRQ(ierr);
151   ierr = PetscSFCreate(PetscObjectComm((PetscObject)dm), sfz);CHKERRQ(ierr);
152   ierr = PetscObjectSetName((PetscObject) *sfz, "Buffered Map");CHKERRQ(ierr);
153   ierr = PetscSFSetGraph(*sfz, M*N*P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES);CHKERRQ(ierr);
154 
155   ierr = PetscFree2(localPoints, remotePoints);CHKERRQ(ierr);
156   PetscFunctionReturn(0);
157 }
158 
159 typedef enum {PATCH_COMM_TYPE_WORLD = 0, PATCH_COMM_TYPE_SELF = 1} PatchCommType;
160 
161 PetscErrorCode DMPatchSolve(DM dm)
162 {
163   MPI_Comm       comm;
164   MPI_Comm       commz;
165   DM             dmc;
166   PetscSF        sfz, sfzr;
167   Vec            XC;
168   MatStencil     patchSize, commSize, gridRank, lower, upper;
169   PetscInt       M, N, P, i, j, k, l, m, n, p = 0;
170   PetscMPIInt    rank, size;
171   PetscInt       debug = 0;
172   PetscErrorCode ierr;
173 
174   PetscFunctionBegin;
175   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
176   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
177   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
178   ierr = DMPatchGetCoarse(dm, &dmc);CHKERRQ(ierr);
179   ierr = DMPatchGetPatchSize(dm, &patchSize);CHKERRQ(ierr);
180   ierr = DMPatchGetCommSize(dm, &commSize);CHKERRQ(ierr);
181   ierr = DMPatchGetCommSize(dm, &commSize);CHKERRQ(ierr);
182   ierr = DMGetGlobalVector(dmc, &XC);CHKERRQ(ierr);
183   ierr = DMDAGetInfo(dmc, NULL, &M, &N, &P, &l, &m, &n, NULL,NULL,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
184   M    = PetscMax(M, 1); l = PetscMax(l, 1);
185   N    = PetscMax(N, 1); m = PetscMax(m, 1);
186   P    = PetscMax(P, 1); n = PetscMax(n, 1);
187 
188   gridRank.i = rank       % l;
189   gridRank.j = rank/l     % m;
190   gridRank.k = rank/(l*m) % n;
191 
192   if (commSize.i*commSize.j*commSize.k == size || commSize.i*commSize.j*commSize.k == 0) {
193     commSize.i = l; commSize.j = m; commSize.k = n;
194     commz      = comm;
195   } else if (commSize.i*commSize.j*commSize.k == 1) {
196     commz = PETSC_COMM_SELF;
197   } else {
198     const PetscMPIInt newComm = ((gridRank.k/commSize.k)*(m/commSize.j) + gridRank.j/commSize.j)*(l/commSize.i) + (gridRank.i/commSize.i);
199     const PetscMPIInt newRank = ((gridRank.k%commSize.k)*commSize.j     + gridRank.j%commSize.j)*commSize.i     + (gridRank.i%commSize.i);
200 
201     ierr = MPI_Comm_split(comm, newComm, newRank, &commz);CHKERRQ(ierr);
202     if (debug) {ierr = PetscPrintf(PETSC_COMM_SELF, "Rank %d color %d key %d commz %d\n", rank, newComm, newRank, *((PetscMPIInt*) &commz));CHKERRQ(ierr);}
203   }
204   /*
205    Assumptions:
206      - patchSize divides gridSize
207      - commSize divides gridSize
208      - commSize divides l,m,n
209    Ignore multiple patches per rank for now
210 
211    Multiple ranks per patch:
212      - l,m,n divides patchSize
213      - commSize divides patchSize
214    */
215   for (k = 0; k < P; k += PetscMax(patchSize.k, 1)) {
216     for (j = 0; j < N; j += PetscMax(patchSize.j, 1)) {
217       for (i = 0; i < M; i += PetscMax(patchSize.i, 1), ++p) {
218         MPI_Comm commp = MPI_COMM_NULL;
219         DM       dmz   = NULL;
220 #if 0
221         DM  dmf     = NULL;
222         Mat interpz = NULL;
223 #endif
224         Vec         XZ       = NULL;
225         PetscScalar *xcarray = NULL;
226         PetscScalar *xzarray = NULL;
227 
228         if ((gridRank.k/commSize.k == p/(l/commSize.i * m/commSize.j) % n/commSize.k) &&
229             (gridRank.j/commSize.j == p/(l/commSize.i)                % m/commSize.j) &&
230             (gridRank.i/commSize.i == p                               % l/commSize.i)) {
231           if (debug) {ierr = PetscPrintf(PETSC_COMM_SELF, "Rank %d is accepting Patch %d\n", rank, p);CHKERRQ(ierr);}
232           commp = commz;
233         }
234         /* Zoom to coarse patch */
235         lower.i = i; lower.j = j; lower.k = k;
236         upper.i = i + patchSize.i; upper.j = j + patchSize.j; upper.k = k + patchSize.k;
237         ierr    = DMPatchZoom(dmc, XC, lower, upper, commp, &dmz, &sfz, &sfzr);CHKERRQ(ierr);
238         lower.c = 0; /* initialize member, otherwise compiler issues warnings */
239         upper.c = 0; /* initialize member, otherwise compiler issues warnings */
240         /* Debug */
241         ierr = PetscPrintf(comm, "Patch %d: (%d, %d, %d)--(%d, %d, %d)\n", p, lower.i, lower.j, lower.k, upper.i, upper.j, upper.k);CHKERRQ(ierr);
242         if (dmz) {ierr = DMView(dmz, PETSC_VIEWER_STDOUT_(commz));CHKERRQ(ierr);}
243         ierr = PetscSFView(sfz,  PETSC_VIEWER_STDOUT_(comm));CHKERRQ(ierr);
244         ierr = PetscSFView(sfzr, PETSC_VIEWER_STDOUT_(comm));CHKERRQ(ierr);
245         /* Scatter Xcoarse -> Xzoom */
246         if (dmz) {ierr = DMGetGlobalVector(dmz, &XZ);CHKERRQ(ierr);}
247         if (XZ)  {ierr = VecGetArray(XZ, &xzarray);CHKERRQ(ierr);}
248         ierr = VecGetArray(XC, &xcarray);CHKERRQ(ierr);
249         ierr = PetscSFBcastBegin(sfz, MPIU_SCALAR, xcarray, xzarray);CHKERRQ(ierr);
250         ierr = PetscSFBcastEnd(sfz, MPIU_SCALAR, xcarray, xzarray);CHKERRQ(ierr);
251         ierr = VecRestoreArray(XC, &xcarray);CHKERRQ(ierr);
252         if (XZ)  {ierr = VecRestoreArray(XZ, &xzarray);CHKERRQ(ierr);}
253 #if 0
254         /* Interpolate Xzoom -> Xfine, note that this may be on subcomms */
255         ierr = DMRefine(dmz, MPI_COMM_NULL, &dmf);CHKERRQ(ierr);
256         ierr = DMCreateInterpolation(dmz, dmf, &interpz, NULL);CHKERRQ(ierr);
257         ierr = DMInterpolate(dmz, interpz, dmf);CHKERRQ(ierr);
258         /* Smooth Xfine using two-step smoother, normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine */
259         /* Compute residual Rfine */
260         /* Restrict Rfine to Rzoom_restricted */
261 #endif
262         /* Scatter Rzoom_restricted -> Rcoarse_restricted */
263         if (XZ)  {ierr = VecGetArray(XZ, &xzarray);CHKERRQ(ierr);}
264         ierr = VecGetArray(XC, &xcarray);CHKERRQ(ierr);
265         ierr = PetscSFReduceBegin(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM);CHKERRQ(ierr);
266         ierr = PetscSFReduceEnd(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM);CHKERRQ(ierr);
267         ierr = VecRestoreArray(XC, &xcarray);CHKERRQ(ierr);
268         if (XZ)  {ierr = VecRestoreArray(XZ, &xzarray);CHKERRQ(ierr);}
269         if (dmz) {ierr = DMRestoreGlobalVector(dmz, &XZ);CHKERRQ(ierr);}
270         /* Compute global residual Rcoarse */
271         /* TauCoarse = Rcoarse - Rcoarse_restricted */
272 
273         ierr = PetscSFDestroy(&sfz);CHKERRQ(ierr);
274         ierr = PetscSFDestroy(&sfzr);CHKERRQ(ierr);
275         ierr = DMDestroy(&dmz);CHKERRQ(ierr);
276       }
277     }
278   }
279   ierr = DMRestoreGlobalVector(dmc, &XC);CHKERRQ(ierr);
280   PetscFunctionReturn(0);
281 }
282 
283 PetscErrorCode DMPatchView_Ascii(DM dm, PetscViewer viewer)
284 {
285   DM_Patch          *mesh = (DM_Patch*) dm->data;
286   PetscViewerFormat format;
287   const char        *name;
288   PetscErrorCode    ierr;
289 
290   PetscFunctionBegin;
291   ierr = PetscViewerGetFormat(viewer, &format);CHKERRQ(ierr);
292   /* if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) */
293   ierr = PetscObjectGetName((PetscObject) dm, &name);CHKERRQ(ierr);
294   ierr = PetscViewerASCIIPrintf(viewer, "Patch DM %s\n", name);CHKERRQ(ierr);
295   ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
296   ierr = PetscViewerASCIIPrintf(viewer, "Coarse DM\n");CHKERRQ(ierr);
297   ierr = DMView(mesh->dmCoarse, viewer);CHKERRQ(ierr);
298   ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
299   PetscFunctionReturn(0);
300 }
301 
302 PetscErrorCode DMView_Patch(DM dm, PetscViewer viewer)
303 {
304   PetscBool      iascii, isbinary;
305   PetscErrorCode ierr;
306 
307   PetscFunctionBegin;
308   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
309   PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 2);
310   ierr = PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &iascii);CHKERRQ(ierr);
311   ierr = PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERBINARY, &isbinary);CHKERRQ(ierr);
312   if (iascii) {
313     ierr = DMPatchView_Ascii(dm, viewer);CHKERRQ(ierr);
314 #if 0
315   } else if (isbinary) {
316     ierr = DMPatchView_Binary(dm, viewer);CHKERRQ(ierr);
317 #endif
318   }
319   PetscFunctionReturn(0);
320 }
321 
322 PetscErrorCode DMDestroy_Patch(DM dm)
323 {
324   DM_Patch       *mesh = (DM_Patch*) dm->data;
325   PetscErrorCode ierr;
326 
327   PetscFunctionBegin;
328   if (--mesh->refct > 0) PetscFunctionReturn(0);
329   ierr = DMDestroy(&mesh->dmCoarse);CHKERRQ(ierr);
330   /* This was originally freed in DMDestroy(), but that prevents reference counting of backend objects */
331   ierr = PetscFree(mesh);CHKERRQ(ierr);
332   PetscFunctionReturn(0);
333 }
334 
335 PetscErrorCode DMSetUp_Patch(DM dm)
336 {
337   DM_Patch       *mesh = (DM_Patch*) dm->data;
338   PetscErrorCode ierr;
339 
340   PetscFunctionBegin;
341   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
342   ierr = DMSetUp(mesh->dmCoarse);CHKERRQ(ierr);
343   PetscFunctionReturn(0);
344 }
345 
346 PetscErrorCode DMCreateGlobalVector_Patch(DM dm, Vec *g)
347 {
348   DM_Patch       *mesh = (DM_Patch*) dm->data;
349   PetscErrorCode ierr;
350 
351   PetscFunctionBegin;
352   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
353   ierr = DMCreateGlobalVector(mesh->dmCoarse, g);CHKERRQ(ierr);
354   PetscFunctionReturn(0);
355 }
356 
357 PetscErrorCode DMCreateLocalVector_Patch(DM dm, Vec *l)
358 {
359   DM_Patch       *mesh = (DM_Patch*) dm->data;
360   PetscErrorCode ierr;
361 
362   PetscFunctionBegin;
363   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
364   ierr = DMCreateLocalVector(mesh->dmCoarse, l);CHKERRQ(ierr);
365   PetscFunctionReturn(0);
366 }
367 
368 PetscErrorCode DMCreateSubDM_Patch(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
369 {
370   SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Tell me to code this");
371 }
372 
373 PetscErrorCode DMPatchGetCoarse(DM dm, DM *dmCoarse)
374 {
375   DM_Patch *mesh = (DM_Patch*) dm->data;
376 
377   PetscFunctionBegin;
378   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
379   *dmCoarse = mesh->dmCoarse;
380   PetscFunctionReturn(0);
381 }
382 
383 PetscErrorCode DMPatchGetPatchSize(DM dm, MatStencil *patchSize)
384 {
385   DM_Patch *mesh = (DM_Patch*) dm->data;
386 
387   PetscFunctionBegin;
388   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
389   PetscValidPointer(patchSize, 2);
390   *patchSize = mesh->patchSize;
391   PetscFunctionReturn(0);
392 }
393 
394 PetscErrorCode DMPatchSetPatchSize(DM dm, MatStencil patchSize)
395 {
396   DM_Patch *mesh = (DM_Patch*) dm->data;
397 
398   PetscFunctionBegin;
399   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
400   mesh->patchSize = patchSize;
401   PetscFunctionReturn(0);
402 }
403 
404 PetscErrorCode DMPatchGetCommSize(DM dm, MatStencil *commSize)
405 {
406   DM_Patch *mesh = (DM_Patch*) dm->data;
407 
408   PetscFunctionBegin;
409   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
410   PetscValidPointer(commSize, 2);
411   *commSize = mesh->commSize;
412   PetscFunctionReturn(0);
413 }
414 
415 PetscErrorCode DMPatchSetCommSize(DM dm, MatStencil commSize)
416 {
417   DM_Patch *mesh = (DM_Patch*) dm->data;
418 
419   PetscFunctionBegin;
420   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
421   mesh->commSize = commSize;
422   PetscFunctionReturn(0);
423 }
424