Date: 2022-03-04T17:38:31+00:00

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

     24:   Collective on dm

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

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

     36:   Level: intermediate

     38: .seealso: DMPatchSolve(), DMDACreatePatchIS()
     39: @*/
     40: PetscErrorCode DMPatchZoom(DM dm, MatStencil lower, MatStencil upper, MPI_Comm commz, DM *dmz, PetscSF *sfz, PetscSF *sfzr)
     41: {
     42:   DMDAStencilType st;
     43:   MatStencil      blower, bupper, loclower, locupper;
     44:   IS              is;
     45:   const PetscInt  *ranges, *indices;
     46:   PetscInt        *localPoints  = NULL;
     47:   PetscSFNode     *remotePoints = NULL;
     48:   PetscInt        dim, dof;
     49:   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;
     50:   PetscMPIInt     size;
     51:   PetscBool       patchis_offproc = PETSC_TRUE;
     52:   PetscErrorCode  ierr;
     53:   Vec             X;

     56:   if (!sfz) halo = 0;
     57:   MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size);
     58:   /* Create patch DM */
     59:   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); 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;

     69:   if (commz != MPI_COMM_NULL) {
     70:     DMDACreate(commz, dmz);
     71:     DMSetDimension(*dmz, dim);
     72:     DMDASetSizes(*dmz, rM, rN, rP);
     73:     DMDASetNumProcs(*dmz, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE);
     74:     DMDASetBoundaryType(*dmz, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE);
     75:     DMDASetDof(*dmz, dof);
     76:     DMDASetStencilType(*dmz, st);
     77:     DMDASetStencilWidth(*dmz, 0);
     78:     DMDASetOwnershipRanges(*dmz, NULL, NULL, NULL);
     79:     DMSetFromOptions(*dmz);
     80:     DMSetUp(*dmz);
     81:     DMDAGetCorners(*dmz, &sxb, &syb, &szb, &mxb, &myb, &mzb);
     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:     PetscMalloc2(dof*rM*rN*PetscMax(rP,1),&localPoints,dof*rM*rN*PetscMax(rP,1),&remotePoints);
     89:   } else {
     90:     sxr = syr = szr = exr = eyr = ezr = sxb = syb = szb = mxb = myb = mzb = 0;
     91:   }

     93:   /* Create SF for restricted map */
     94:   DMCreateGlobalVector(dm,&X);
     95:   VecGetOwnershipRanges(X,&ranges);

     97:   loclower.i = blower.i + sxr; locupper.i = blower.i + exr;
     98:   loclower.j = blower.j + syr; locupper.j = blower.j + eyr;
     99:   loclower.k = blower.k + szr; locupper.k = blower.k + ezr;

    101:   DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc);
    102:   ISGetIndices(is, &indices);

    104:   if (dim < 3) {mzb = 1; ezr = 1;}
    105:   q = 0;
    106:   for (k = szb; k < szb+mzb; ++k) {
    107:     if ((k < szr) || (k >= ezr)) continue;
    108:     for (j = syb; j < syb+myb; ++j) {
    109:       if ((j < syr) || (j >= eyr)) continue;
    110:       for (i = sxb; i < sxb+mxb; ++i) {
    111:         for (l=0; l<dof; l++) {
    112:           const PetscInt lp = l + dof*(((k-szb)*rN + (j-syb))*rM + i-sxb);
    113:           PetscInt       r;

    115:           if ((i < sxr) || (i >= exr)) continue;
    116:           localPoints[q]        = lp;
    117:           PetscFindInt(indices[q], size+1, ranges, &r);

    119:           remotePoints[q].rank  = r < 0 ? -(r+1) - 1 : r;
    120:           remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
    121:           ++q;
    122:         }
    123:       }
    124:     }
    125:   }
    126:   ISRestoreIndices(is, &indices);
    127:   ISDestroy(&is);
    128:   PetscSFCreate(PetscObjectComm((PetscObject)dm), sfzr);
    129:   PetscObjectSetName((PetscObject) *sfzr, "Restricted Map");
    130:   PetscSFSetGraph(*sfzr, dof*M*N*P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES);

    132:   if (sfz) {
    133:     /* Create SF for buffered map */
    134:     loclower.i = blower.i + sxb; locupper.i = blower.i + sxb+mxb;
    135:     loclower.j = blower.j + syb; locupper.j = blower.j + syb+myb;
    136:     loclower.k = blower.k + szb; locupper.k = blower.k + szb+mzb;

    138:     DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc);
    139:     ISGetIndices(is, &indices);

    141:     q = 0;
    142:     for (k = szb; k < szb+mzb; ++k) {
    143:       for (j = syb; j < syb+myb; ++j) {
    144:         for (i = sxb; i < sxb+mxb; ++i, ++q) {
    145:           PetscInt r;

    147:           localPoints[q]        = q;
    148:           PetscFindInt(indices[q], size+1, ranges, &r);
    149:           remotePoints[q].rank  = r < 0 ? -(r+1) - 1 : r;
    150:           remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
    151:         }
    152:       }
    153:     }
    154:     ISRestoreIndices(is, &indices);
    155:     ISDestroy(&is);
    156:     PetscSFCreate(PetscObjectComm((PetscObject)dm), sfz);
    157:     PetscObjectSetName((PetscObject) *sfz, "Buffered Map");
    158:     PetscSFSetGraph(*sfz, M*N*P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES);
    159:   }

    161:   VecDestroy(&X);
    162:   PetscFree2(localPoints, remotePoints);
    163:   return(0);
    164: }

    166: typedef enum {PATCH_COMM_TYPE_WORLD = 0, PATCH_COMM_TYPE_SELF = 1} PatchCommType;

    168: PetscErrorCode DMPatchSolve(DM dm)
    169: {
    170:   MPI_Comm       comm;
    171:   MPI_Comm       commz;
    172:   DM             dmc;
    173:   PetscSF        sfz, sfzr;
    174:   Vec            XC;
    175:   MatStencil     patchSize, commSize, gridRank, lower, upper;
    176:   PetscInt       M, N, P, i, j, k, l, m, n, p = 0;
    177:   PetscMPIInt    rank, size;
    178:   PetscInt       debug = 0;

    182:   PetscObjectGetComm((PetscObject)dm,&comm);
    183:   MPI_Comm_rank(comm, &rank);
    184:   MPI_Comm_size(comm, &size);
    185:   DMPatchGetCoarse(dm, &dmc);
    186:   DMPatchGetPatchSize(dm, &patchSize);
    187:   DMPatchGetCommSize(dm, &commSize);
    188:   DMPatchGetCommSize(dm, &commSize);
    189:   DMGetGlobalVector(dmc, &XC);
    190:   DMDAGetInfo(dmc, NULL, &M, &N, &P, &l, &m, &n, NULL,NULL,NULL,NULL,NULL,NULL);
    191:   M    = PetscMax(M, 1); l = PetscMax(l, 1);
    192:   N    = PetscMax(N, 1); m = PetscMax(m, 1);
    193:   P    = PetscMax(P, 1); n = PetscMax(n, 1);

    195:   gridRank.i = rank       % l;
    196:   gridRank.j = rank/l     % m;
    197:   gridRank.k = rank/(l*m) % n;

    199:   if (commSize.i*commSize.j*commSize.k == size || commSize.i*commSize.j*commSize.k == 0) {
    200:     commSize.i = l; commSize.j = m; commSize.k = n;
    201:     commz      = comm;
    202:   } else if (commSize.i*commSize.j*commSize.k == 1) {
    203:     commz = PETSC_COMM_SELF;
    204:   } else {
    205:     const PetscMPIInt newComm = ((gridRank.k/commSize.k)*(m/commSize.j) + gridRank.j/commSize.j)*(l/commSize.i) + (gridRank.i/commSize.i);
    206:     const PetscMPIInt newRank = ((gridRank.k%commSize.k)*commSize.j     + gridRank.j%commSize.j)*commSize.i     + (gridRank.i%commSize.i);

    208:     MPI_Comm_split(comm, newComm, newRank, &commz);
    209:     if (debug) {PetscPrintf(PETSC_COMM_SELF, "Rank %d color %d key %d commz %d\n", rank, newComm, newRank, *((PetscMPIInt*) &commz));}
    210:   }
    211:   /*
    212:    Assumptions:
    213:      - patchSize divides gridSize
    214:      - commSize divides gridSize
    215:      - commSize divides l,m,n
    216:    Ignore multiple patches per rank for now

    218:    Multiple ranks per patch:
    219:      - l,m,n divides patchSize
    220:      - commSize divides patchSize
    221:    */
    222:   for (k = 0; k < P; k += PetscMax(patchSize.k, 1)) {
    223:     for (j = 0; j < N; j += PetscMax(patchSize.j, 1)) {
    224:       for (i = 0; i < M; i += PetscMax(patchSize.i, 1), ++p) {
    225:         MPI_Comm    commp = MPI_COMM_NULL;
    226:         DM          dmz   = NULL;
    227: #if 0
    228:         DM          dmf     = NULL;
    229:         Mat         interpz = NULL;
    230: #endif
    231:         Vec         XZ       = NULL;
    232:         PetscScalar *xcarray = NULL;
    233:         PetscScalar *xzarray = NULL;

    235:         if ((gridRank.k/commSize.k == p/(l/commSize.i * m/commSize.j) % n/commSize.k) &&
    236:             (gridRank.j/commSize.j == p/(l/commSize.i)                % m/commSize.j) &&
    237:             (gridRank.i/commSize.i == p                               % l/commSize.i)) {
    238:           if (debug) {PetscPrintf(PETSC_COMM_SELF, "Rank %d is accepting Patch %d\n", rank, p);}
    239:           commp = commz;
    240:         }
    241:         /* Zoom to coarse patch */
    242:         lower.i = i; lower.j = j; lower.k = k;
    243:         upper.i = i + patchSize.i; upper.j = j + patchSize.j; upper.k = k + patchSize.k;
    244:         DMPatchZoom(dmc, lower, upper, commp, &dmz, &sfz, &sfzr);
    245:         lower.c = 0; /* initialize member, otherwise compiler issues warnings */
    246:         upper.c = 0; /* initialize member, otherwise compiler issues warnings */
    247:         if (debug) {PetscPrintf(comm, "Patch %d: (%d, %d, %d)--(%d, %d, %d)\n", p, lower.i, lower.j, lower.k, upper.i, upper.j, upper.k);}
    248:         if (dmz) {DMView(dmz, PETSC_VIEWER_STDOUT_(commz));}
    249:         PetscSFView(sfz,  PETSC_VIEWER_STDOUT_(comm));
    250:         PetscSFView(sfzr, PETSC_VIEWER_STDOUT_(comm));
    251:         /* Scatter Xcoarse -> Xzoom */
    252:         if (dmz) {DMGetGlobalVector(dmz, &XZ);}
    253:         if (XZ)  {VecGetArray(XZ, &xzarray);}
    254:         VecGetArray(XC, &xcarray);
    255:         PetscSFBcastBegin(sfz, MPIU_SCALAR, xcarray, xzarray,MPI_REPLACE);
    256:         PetscSFBcastEnd(sfz, MPIU_SCALAR, xcarray, xzarray,MPI_REPLACE);
    257:         VecRestoreArray(XC, &xcarray);
    258:         if (XZ)  {VecRestoreArray(XZ, &xzarray);}
    259: #if 0
    260:         /* Interpolate Xzoom -> Xfine, note that this may be on subcomms */
    261:         DMRefine(dmz, MPI_COMM_NULL, &dmf);
    262:         DMCreateInterpolation(dmz, dmf, &interpz, NULL);
    263:         DMInterpolate(dmz, interpz, dmf);
    264:         /* Smooth Xfine using two-step smoother, normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine */
    265:         /* Compute residual Rfine */
    266:         /* Restrict Rfine to Rzoom_restricted */
    267: #endif
    268:         /* Scatter Rzoom_restricted -> Rcoarse_restricted */
    269:         if (XZ)  {VecGetArray(XZ, &xzarray);}
    270:         VecGetArray(XC, &xcarray);
    271:         PetscSFReduceBegin(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM);
    272:         PetscSFReduceEnd(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM);
    273:         VecRestoreArray(XC, &xcarray);
    274:         if (XZ)  {VecRestoreArray(XZ, &xzarray);}
    275:         if (dmz) {DMRestoreGlobalVector(dmz, &XZ);}
    276:         /* Compute global residual Rcoarse */
    277:         /* TauCoarse = Rcoarse - Rcoarse_restricted */

    279:         PetscSFDestroy(&sfz);
    280:         PetscSFDestroy(&sfzr);
    281:         DMDestroy(&dmz);
    282:       }
    283:     }
    284:   }
    285:   DMRestoreGlobalVector(dmc, &XC);
    286:   return(0);
    287: }

    289: PetscErrorCode DMPatchView_ASCII(DM dm, PetscViewer viewer)
    290: {
    291:   DM_Patch          *mesh = (DM_Patch*) dm->data;
    292:   PetscViewerFormat format;
    293:   const char        *name;
    294:   PetscErrorCode    ierr;

    297:   PetscViewerGetFormat(viewer, &format);
    298:   /* if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) */
    299:   PetscObjectGetName((PetscObject) dm, &name);
    300:   PetscViewerASCIIPrintf(viewer, "Patch DM %s\n", name);
    301:   PetscViewerASCIIPushTab(viewer);
    302:   PetscViewerASCIIPrintf(viewer, "Coarse DM\n");
    303:   DMView(mesh->dmCoarse, viewer);
    304:   PetscViewerASCIIPopTab(viewer);
    305:   return(0);
    306: }

    308: PetscErrorCode DMView_Patch(DM dm, PetscViewer viewer)
    309: {
    310:   PetscBool      iascii, isbinary;

    316:   PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &iascii);
    317:   PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERBINARY, &isbinary);
    318:   if (iascii) {
    319:     DMPatchView_ASCII(dm, viewer);
    320:   }
    321:   return(0);
    322: }

    324: PetscErrorCode DMDestroy_Patch(DM dm)
    325: {
    326:   DM_Patch       *mesh = (DM_Patch*) dm->data;

    330:   if (--mesh->refct > 0) return(0);
    331:   DMDestroy(&mesh->dmCoarse);
    332:   /* This was originally freed in DMDestroy(), but that prevents reference counting of backend objects */
    333:   PetscFree(mesh);
    334:   return(0);
    335: }

    337: PetscErrorCode DMSetUp_Patch(DM dm)
    338: {
    339:   DM_Patch       *mesh = (DM_Patch*) dm->data;

    344:   DMSetUp(mesh->dmCoarse);
    345:   return(0);
    346: }

    348: PetscErrorCode DMCreateGlobalVector_Patch(DM dm, Vec *g)
    349: {
    350:   DM_Patch       *mesh = (DM_Patch*) dm->data;

    355:   DMCreateGlobalVector(mesh->dmCoarse, g);
    356:   return(0);
    357: }

    359: PetscErrorCode DMCreateLocalVector_Patch(DM dm, Vec *l)
    360: {
    361:   DM_Patch       *mesh = (DM_Patch*) dm->data;

    366:   DMCreateLocalVector(mesh->dmCoarse, l);
    367:   return(0);
    368: }

    370: PetscErrorCode DMCreateSubDM_Patch(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
    371: {
    372:   SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Tell me to code this");
    373: }

    375: PetscErrorCode DMPatchGetCoarse(DM dm, DM *dmCoarse)
    376: {
    377:   DM_Patch *mesh = (DM_Patch*) dm->data;

    381:   *dmCoarse = mesh->dmCoarse;
    382:   return(0);
    383: }

    385: PetscErrorCode DMPatchGetPatchSize(DM dm, MatStencil *patchSize)
    386: {
    387:   DM_Patch *mesh = (DM_Patch*) dm->data;

    392:   *patchSize = mesh->patchSize;
    393:   return(0);
    394: }

    396: PetscErrorCode DMPatchSetPatchSize(DM dm, MatStencil patchSize)
    397: {
    398:   DM_Patch *mesh = (DM_Patch*) dm->data;

    402:   mesh->patchSize = patchSize;
    403:   return(0);
    404: }

    406: PetscErrorCode DMPatchGetCommSize(DM dm, MatStencil *commSize)
    407: {
    408:   DM_Patch *mesh = (DM_Patch*) dm->data;

    413:   *commSize = mesh->commSize;
    414:   return(0);
    415: }

    417: PetscErrorCode DMPatchSetCommSize(DM dm, MatStencil commSize)
    418: {
    419:   DM_Patch *mesh = (DM_Patch*) dm->data;

    423:   mesh->commSize = commSize;
    424:   return(0);
    425: }