xref: /petsc/src/ksp/pc/impls/redundant/redundant.c (revision 65e19b508233067d6906a3416498cb9734b3efd5)
1dba47a55SKris Buschelman #define PETSCKSP_DLL
2dba47a55SKris Buschelman 
34b9ad928SBarry Smith /*
43f457be1SHong Zhang   This file defines a "solve the problem redundantly on each subgroup of processor" preconditioner.
54b9ad928SBarry Smith */
66356e834SBarry Smith #include "private/pcimpl.h"     /*I "petscpc.h" I*/
74b9ad928SBarry Smith #include "petscksp.h"
84b9ad928SBarry Smith 
94b9ad928SBarry Smith typedef struct {
103e065800SHong Zhang   KSP          ksp;
114b9ad928SBarry Smith   PC           pc;                   /* actual preconditioner used on each processor */
127adad957SLisandro Dalcin   Vec          xsub,ysub;            /* vectors of a subcommunicator to hold parallel vectors of ((PetscObject)pc)->comm */
133f457be1SHong Zhang   Vec          xdup,ydup;            /* parallel vector that congregates xsub or ysub facilitating vector scattering */
14b3804887SHong Zhang   Mat          pmats;                /* matrix and optional preconditioner matrix belong to a subcommunicator */
153f457be1SHong Zhang   VecScatter   scatterin,scatterout; /* scatter used to move all values to each processor group (subcommunicator) */
164b9ad928SBarry Smith   PetscTruth   useparallelmat;
17c540e29cSHong Zhang   PetscSubcomm psubcomm;
181fbd8f88SHong Zhang   PetscInt     nsubcomm;           /* num of data structure PetscSubcomm */
194b9ad928SBarry Smith } PC_Redundant;
204b9ad928SBarry Smith 
214b9ad928SBarry Smith #undef __FUNCT__
224b9ad928SBarry Smith #define __FUNCT__ "PCView_Redundant"
236849ba73SBarry Smith static PetscErrorCode PCView_Redundant(PC pc,PetscViewer viewer)
244b9ad928SBarry Smith {
254b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
26dfbe8321SBarry Smith   PetscErrorCode ierr;
2713f74950SBarry Smith   PetscMPIInt    rank;
2832077d6dSBarry Smith   PetscTruth     iascii,isstring;
2903ccd0b4SBarry Smith   PetscViewer    subviewer;
304b9ad928SBarry Smith 
314b9ad928SBarry Smith   PetscFunctionBegin;
327adad957SLisandro Dalcin   ierr = MPI_Comm_rank(((PetscObject)pc)->comm,&rank);CHKERRQ(ierr);
3332077d6dSBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);CHKERRQ(ierr);
344b9ad928SBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_STRING,&isstring);CHKERRQ(ierr);
3532077d6dSBarry Smith   if (iascii) {
3603ccd0b4SBarry Smith     if (!red->psubcomm) {
3703ccd0b4SBarry Smith       ierr = PetscViewerASCIIPrintf(viewer,"  Redundant preconditioner: Not yet setup\n");CHKERRQ(ierr);
3803ccd0b4SBarry Smith     } else {
393e065800SHong Zhang       ierr = PetscViewerASCIIPrintf(viewer,"  Redundant preconditioner: First (color=0) of %D PCs follows\n",red->nsubcomm);CHKERRQ(ierr);
407adad957SLisandro Dalcin       ierr = PetscViewerGetSubcomm(viewer,((PetscObject)red->pc)->comm,&subviewer);CHKERRQ(ierr);
4103ccd0b4SBarry Smith       if (red->psubcomm->color) { /* only view first redundant pc */
424b9ad928SBarry Smith 	ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
433e065800SHong Zhang 	ierr = KSPView(red->ksp,subviewer);CHKERRQ(ierr);
444b9ad928SBarry Smith 	ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
454b9ad928SBarry Smith       }
467adad957SLisandro Dalcin       ierr = PetscViewerRestoreSubcomm(viewer,((PetscObject)red->pc)->comm,&subviewer);CHKERRQ(ierr);
474b9ad928SBarry Smith     }
4803ccd0b4SBarry Smith   } else if (isstring) {
4903ccd0b4SBarry Smith     ierr = PetscViewerStringSPrintf(viewer," Redundant solver preconditioner");CHKERRQ(ierr);
504b9ad928SBarry Smith   } else {
51*65e19b50SBarry Smith     SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_SUP,"Viewer type %s not supported for PC redundant",((PetscObject)viewer)->type_name);
524b9ad928SBarry Smith   }
534b9ad928SBarry Smith   PetscFunctionReturn(0);
544b9ad928SBarry Smith }
554b9ad928SBarry Smith 
564b9ad928SBarry Smith #undef __FUNCT__
574b9ad928SBarry Smith #define __FUNCT__ "PCSetUp_Redundant"
586849ba73SBarry Smith static PetscErrorCode PCSetUp_Redundant(PC pc)
594b9ad928SBarry Smith {
604b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
61dfbe8321SBarry Smith   PetscErrorCode ierr;
6245fc02eaSBarry Smith   PetscInt       mstart,mend,mlocal,m,mlocal_sub,rstart_sub,rend_sub,mloc_sub;
6313f74950SBarry Smith   PetscMPIInt    size;
644b9ad928SBarry Smith   MatReuse       reuse = MAT_INITIAL_MATRIX;
654b9ad928SBarry Smith   MatStructure   str = DIFFERENT_NONZERO_PATTERN;
667adad957SLisandro Dalcin   MPI_Comm       comm = ((PetscObject)pc)->comm,subcomm;
6723ce1328SBarry Smith   Vec            vec;
683f457be1SHong Zhang   PetscMPIInt    subsize,subrank;
691fbd8f88SHong Zhang   const char     *prefix;
70b862ddfaSBarry Smith   const PetscInt *range;
713f457be1SHong Zhang 
724b9ad928SBarry Smith   PetscFunctionBegin;
7323ce1328SBarry Smith   ierr = MatGetVecs(pc->pmat,&vec,0);CHKERRQ(ierr);
7423ce1328SBarry Smith   ierr = VecGetSize(vec,&m);CHKERRQ(ierr);
751fbd8f88SHong Zhang 
764b9ad928SBarry Smith   if (!pc->setupcalled) {
775f06b7aaSBarry Smith     if (!red->psubcomm) {
781fbd8f88SHong Zhang       ierr = PetscSubcommCreate(comm,red->nsubcomm,&red->psubcomm);CHKERRQ(ierr);
791fbd8f88SHong Zhang       ierr = PetscLogObjectMemory(pc,sizeof(PetscSubcomm));CHKERRQ(ierr);
801fbd8f88SHong Zhang 
811fbd8f88SHong Zhang       /* create a new PC that processors in each subcomm have copy of */
820d7810c8SBarry Smith       subcomm = red->psubcomm->comm;
835f06b7aaSBarry Smith       ierr = KSPCreate(subcomm,&red->ksp);CHKERRQ(ierr);
845f06b7aaSBarry Smith       ierr = PetscObjectIncrementTabLevel((PetscObject)red->ksp,(PetscObject)pc,1);CHKERRQ(ierr);
855f06b7aaSBarry Smith       ierr = PetscLogObjectParent(pc,red->ksp);CHKERRQ(ierr);
865f06b7aaSBarry Smith       ierr = KSPSetType(red->ksp,KSPPREONLY);CHKERRQ(ierr);
875f06b7aaSBarry Smith       ierr = KSPGetPC(red->ksp,&red->pc);CHKERRQ(ierr);
88cf52b8b1SHong Zhang       ierr = PCSetType(red->pc,PCLU);CHKERRQ(ierr);
89cf52b8b1SHong Zhang 
901fbd8f88SHong Zhang       ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
915f06b7aaSBarry Smith       ierr = KSPSetOptionsPrefix(red->ksp,prefix);CHKERRQ(ierr);
925f06b7aaSBarry Smith       ierr = KSPAppendOptionsPrefix(red->ksp,"redundant_");CHKERRQ(ierr);
935f06b7aaSBarry Smith     } else {
945f06b7aaSBarry Smith        subcomm = red->psubcomm->comm;
955f06b7aaSBarry Smith     }
961fbd8f88SHong Zhang 
973f457be1SHong Zhang     /* create working vectors xsub/ysub and xdup/ydup */
9823ce1328SBarry Smith     ierr = VecGetLocalSize(vec,&mlocal);CHKERRQ(ierr);
993f457be1SHong Zhang     ierr = VecGetOwnershipRange(vec,&mstart,&mend);CHKERRQ(ierr);
1004b9ad928SBarry Smith 
1013f457be1SHong Zhang     /* get local size of xsub/ysub */
1021fbd8f88SHong Zhang     ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
1031fbd8f88SHong Zhang     ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
104b862ddfaSBarry Smith     ierr = MatGetOwnershipRanges(pc->pmat,&range);CHKERRQ(ierr);
105b862ddfaSBarry Smith     rstart_sub = range[red->psubcomm->n*subrank]; /* rstart in xsub/ysub */
1063f457be1SHong Zhang     if (subrank+1 < subsize){
107b862ddfaSBarry Smith       rend_sub = range[red->psubcomm->n*(subrank+1)];
1083f457be1SHong Zhang     } else {
1093f457be1SHong Zhang       rend_sub = m;
1103f457be1SHong Zhang     }
1113f457be1SHong Zhang     mloc_sub = rend_sub - rstart_sub;
1121fbd8f88SHong Zhang     ierr = VecCreateMPI(subcomm,mloc_sub,PETSC_DECIDE,&red->ysub);CHKERRQ(ierr);
1133f457be1SHong Zhang     /* create xsub with empty local arrays, because xdup's arrays will be placed into it */
1141fbd8f88SHong Zhang     ierr = VecCreateMPIWithArray(subcomm,mloc_sub,PETSC_DECIDE,PETSC_NULL,&red->xsub);CHKERRQ(ierr);
1153f457be1SHong Zhang 
1163f457be1SHong Zhang     /* create xdup and ydup. ydup has empty local arrays because ysub's arrays will be place into it.
1177adad957SLisandro Dalcin        Note: we use communicator dupcomm, not ((PetscObject)pc)->comm! */
1181fbd8f88SHong Zhang     ierr = VecCreateMPI(red->psubcomm->dupparent,mloc_sub,PETSC_DECIDE,&red->xdup);CHKERRQ(ierr);
1191fbd8f88SHong Zhang     ierr = VecCreateMPIWithArray(red->psubcomm->dupparent,mloc_sub,PETSC_DECIDE,PETSC_NULL,&red->ydup);CHKERRQ(ierr);
1203f457be1SHong Zhang 
1213f457be1SHong Zhang     /* create vec scatters */
1223f457be1SHong Zhang     if (!red->scatterin){
1233f457be1SHong Zhang       IS       is1,is2;
1243f457be1SHong Zhang       PetscInt *idx1,*idx2,i,j,k;
12545fc02eaSBarry Smith 
1261d79065fSBarry Smith       ierr = PetscMalloc2(red->psubcomm->n*mlocal,PetscInt,&idx1,red->psubcomm->n*mlocal,PetscInt,&idx2);CHKERRQ(ierr);
1273f457be1SHong Zhang       j = 0;
1281fbd8f88SHong Zhang       for (k=0; k<red->psubcomm->n; k++){
1293f457be1SHong Zhang         for (i=mstart; i<mend; i++){
1303f457be1SHong Zhang           idx1[j]   = i;
1313f457be1SHong Zhang           idx2[j++] = i + m*k;
1323f457be1SHong Zhang         }
1333f457be1SHong Zhang       }
1341fbd8f88SHong Zhang       ierr = ISCreateGeneral(comm,red->psubcomm->n*mlocal,idx1,&is1);CHKERRQ(ierr);
1351fbd8f88SHong Zhang       ierr = ISCreateGeneral(comm,red->psubcomm->n*mlocal,idx2,&is2);CHKERRQ(ierr);
1363f457be1SHong Zhang       ierr = VecScatterCreate(vec,is1,red->xdup,is2,&red->scatterin);CHKERRQ(ierr);
1373f457be1SHong Zhang       ierr = ISDestroy(is1);CHKERRQ(ierr);
1383f457be1SHong Zhang       ierr = ISDestroy(is2);CHKERRQ(ierr);
1393f457be1SHong Zhang 
1401fbd8f88SHong Zhang       ierr = ISCreateStride(comm,mlocal,mstart+ red->psubcomm->color*m,1,&is1);CHKERRQ(ierr);
1413f457be1SHong Zhang       ierr = ISCreateStride(comm,mlocal,mstart,1,&is2);CHKERRQ(ierr);
1423f457be1SHong Zhang       ierr = VecScatterCreate(red->xdup,is1,vec,is2,&red->scatterout);CHKERRQ(ierr);
1433f457be1SHong Zhang       ierr = ISDestroy(is1);CHKERRQ(ierr);
1443f457be1SHong Zhang       ierr = ISDestroy(is2);CHKERRQ(ierr);
1451d79065fSBarry Smith       ierr = PetscFree2(idx1,idx2);CHKERRQ(ierr);
1464b9ad928SBarry Smith     }
1474b9ad928SBarry Smith   }
14823ce1328SBarry Smith   ierr = VecDestroy(vec);CHKERRQ(ierr);
1494b9ad928SBarry Smith 
1504b9ad928SBarry Smith   /* if pmatrix set by user is sequential then we do not need to gather the parallel matrix */
1513f457be1SHong Zhang   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1524b9ad928SBarry Smith   if (size == 1) {
1534b9ad928SBarry Smith     red->useparallelmat = PETSC_FALSE;
1544b9ad928SBarry Smith   }
1554b9ad928SBarry Smith 
1564b9ad928SBarry Smith   if (red->useparallelmat) {
1574b9ad928SBarry Smith     if (pc->setupcalled == 1 && pc->flag == DIFFERENT_NONZERO_PATTERN) {
1584b9ad928SBarry Smith       /* destroy old matrices */
1594b9ad928SBarry Smith       if (red->pmats) {
160b3804887SHong Zhang         ierr = MatDestroy(red->pmats);CHKERRQ(ierr);
1614b9ad928SBarry Smith       }
1624b9ad928SBarry Smith     } else if (pc->setupcalled == 1) {
1634b9ad928SBarry Smith       reuse = MAT_REUSE_MATRIX;
1644b9ad928SBarry Smith       str   = SAME_NONZERO_PATTERN;
1654b9ad928SBarry Smith     }
1664b9ad928SBarry Smith 
1673f457be1SHong Zhang     /* grab the parallel matrix and put it into processors of a subcomminicator */
168f664ae05SHong Zhang     /*--------------------------------------------------------------------------*/
169f664ae05SHong Zhang     ierr = VecGetLocalSize(red->ysub,&mlocal_sub);CHKERRQ(ierr);
17069db28dcSHong Zhang     ierr = MatGetRedundantMatrix(pc->pmat,red->psubcomm->n,red->psubcomm->comm,mlocal_sub,reuse,&red->pmats);CHKERRQ(ierr);
1713f457be1SHong Zhang     /* tell PC of the subcommunicator its operators */
17290f1c854SHong Zhang     ierr = KSPSetOperators(red->ksp,red->pmats,red->pmats,str);CHKERRQ(ierr);
1734b9ad928SBarry Smith   } else {
17490f1c854SHong Zhang     ierr = KSPSetOperators(red->ksp,pc->mat,pc->pmat,pc->flag);CHKERRQ(ierr);
1754b9ad928SBarry Smith   }
1760c24e6a1SHong Zhang   if (pc->setfromoptionscalled){
1773e065800SHong Zhang     ierr = KSPSetFromOptions(red->ksp);CHKERRQ(ierr);
1780c24e6a1SHong Zhang   }
1793e065800SHong Zhang   ierr = KSPSetUp(red->ksp);CHKERRQ(ierr);
1804b9ad928SBarry Smith   PetscFunctionReturn(0);
1814b9ad928SBarry Smith }
1824b9ad928SBarry Smith 
1834b9ad928SBarry Smith #undef __FUNCT__
1844b9ad928SBarry Smith #define __FUNCT__ "PCApply_Redundant"
1856849ba73SBarry Smith static PetscErrorCode PCApply_Redundant(PC pc,Vec x,Vec y)
1864b9ad928SBarry Smith {
1874b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
188dfbe8321SBarry Smith   PetscErrorCode ierr;
1893f457be1SHong Zhang   PetscScalar    *array;
1904b9ad928SBarry Smith 
1914b9ad928SBarry Smith   PetscFunctionBegin;
1923f457be1SHong Zhang   /* scatter x to xdup */
193ca9f406cSSatish Balay   ierr = VecScatterBegin(red->scatterin,x,red->xdup,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
194ca9f406cSSatish Balay   ierr = VecScatterEnd(red->scatterin,x,red->xdup,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1953f457be1SHong Zhang 
1963f457be1SHong Zhang   /* place xdup's local array into xsub */
1973f457be1SHong Zhang   ierr = VecGetArray(red->xdup,&array);CHKERRQ(ierr);
1983f457be1SHong Zhang   ierr = VecPlaceArray(red->xsub,(const PetscScalar*)array);CHKERRQ(ierr);
1994b9ad928SBarry Smith 
2004b9ad928SBarry Smith   /* apply preconditioner on each processor */
2013f457be1SHong Zhang   ierr = PCApply(red->pc,red->xsub,red->ysub);CHKERRQ(ierr);
2023f457be1SHong Zhang   ierr = VecResetArray(red->xsub);CHKERRQ(ierr);
2033f457be1SHong Zhang   ierr = VecRestoreArray(red->xdup,&array);CHKERRQ(ierr);
2044b9ad928SBarry Smith 
2053f457be1SHong Zhang   /* place ysub's local array into ydup */
2063f457be1SHong Zhang   ierr = VecGetArray(red->ysub,&array);CHKERRQ(ierr);
2073f457be1SHong Zhang   ierr = VecPlaceArray(red->ydup,(const PetscScalar*)array);CHKERRQ(ierr);
2083f457be1SHong Zhang 
2093f457be1SHong Zhang   /* scatter ydup to y */
210ca9f406cSSatish Balay   ierr = VecScatterBegin(red->scatterout,red->ydup,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
211ca9f406cSSatish Balay   ierr = VecScatterEnd(red->scatterout,red->ydup,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2123f457be1SHong Zhang   ierr = VecResetArray(red->ydup);CHKERRQ(ierr);
2133f457be1SHong Zhang   ierr = VecRestoreArray(red->ysub,&array);CHKERRQ(ierr);
2144b9ad928SBarry Smith   PetscFunctionReturn(0);
2154b9ad928SBarry Smith }
2164b9ad928SBarry Smith 
2174b9ad928SBarry Smith #undef __FUNCT__
2184b9ad928SBarry Smith #define __FUNCT__ "PCDestroy_Redundant"
2196849ba73SBarry Smith static PetscErrorCode PCDestroy_Redundant(PC pc)
2204b9ad928SBarry Smith {
2214b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
222dfbe8321SBarry Smith   PetscErrorCode ierr;
2234b9ad928SBarry Smith 
2244b9ad928SBarry Smith   PetscFunctionBegin;
2254b9ad928SBarry Smith   if (red->scatterin)  {ierr = VecScatterDestroy(red->scatterin);CHKERRQ(ierr);}
2264b9ad928SBarry Smith   if (red->scatterout) {ierr = VecScatterDestroy(red->scatterout);CHKERRQ(ierr);}
2273f457be1SHong Zhang   if (red->ysub)       {ierr = VecDestroy(red->ysub);CHKERRQ(ierr);}
2283f457be1SHong Zhang   if (red->xsub)       {ierr = VecDestroy(red->xsub);CHKERRQ(ierr);}
2293f457be1SHong Zhang   if (red->xdup)       {ierr = VecDestroy(red->xdup);CHKERRQ(ierr);}
2303f457be1SHong Zhang   if (red->ydup)       {ierr = VecDestroy(red->ydup);CHKERRQ(ierr);}
231b3804887SHong Zhang   if (red->pmats) {
232b3804887SHong Zhang     ierr = MatDestroy(red->pmats);CHKERRQ(ierr);
2333f457be1SHong Zhang   }
234e5a9bf91SBarry Smith   if (red->psubcomm) {ierr = PetscSubcommDestroy(red->psubcomm);CHKERRQ(ierr);}
2353e065800SHong Zhang   if (red->ksp) {ierr = KSPDestroy(red->ksp);CHKERRQ(ierr);}
2364b9ad928SBarry Smith   ierr = PetscFree(red);CHKERRQ(ierr);
2374b9ad928SBarry Smith   PetscFunctionReturn(0);
2384b9ad928SBarry Smith }
2394b9ad928SBarry Smith 
2404b9ad928SBarry Smith #undef __FUNCT__
2414b9ad928SBarry Smith #define __FUNCT__ "PCSetFromOptions_Redundant"
2426849ba73SBarry Smith static PetscErrorCode PCSetFromOptions_Redundant(PC pc)
2434b9ad928SBarry Smith {
244a98ce0f4SHong Zhang   PetscErrorCode ierr;
245a98ce0f4SHong Zhang   PC_Redundant   *red = (PC_Redundant*)pc->data;
246a98ce0f4SHong Zhang 
2474b9ad928SBarry Smith   PetscFunctionBegin;
248a98ce0f4SHong Zhang   ierr = PetscOptionsHead("Redundant options");CHKERRQ(ierr);
24909a6bc64SHong Zhang   ierr = PetscOptionsInt("-pc_redundant_number","Number of redundant pc","PCRedundantSetNumber",red->nsubcomm,&red->nsubcomm,0);CHKERRQ(ierr);
250a98ce0f4SHong Zhang   ierr = PetscOptionsTail();CHKERRQ(ierr);
2514b9ad928SBarry Smith   PetscFunctionReturn(0);
2524b9ad928SBarry Smith }
2534b9ad928SBarry Smith 
2544b9ad928SBarry Smith EXTERN_C_BEGIN
2554b9ad928SBarry Smith #undef __FUNCT__
25609a6bc64SHong Zhang #define __FUNCT__ "PCRedundantSetNumber_Redundant"
25709a6bc64SHong Zhang PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantSetNumber_Redundant(PC pc,PetscInt nreds)
25809a6bc64SHong Zhang {
25909a6bc64SHong Zhang   PC_Redundant *red = (PC_Redundant*)pc->data;
26009a6bc64SHong Zhang 
26109a6bc64SHong Zhang   PetscFunctionBegin;
26209a6bc64SHong Zhang   red->nsubcomm = nreds;
26309a6bc64SHong Zhang   PetscFunctionReturn(0);
26409a6bc64SHong Zhang }
26509a6bc64SHong Zhang EXTERN_C_END
26609a6bc64SHong Zhang 
26709a6bc64SHong Zhang #undef __FUNCT__
26809a6bc64SHong Zhang #define __FUNCT__ "PCRedundantSetNumber"
26909a6bc64SHong Zhang /*@
27009a6bc64SHong Zhang    PCRedundantSetNumber - Sets the number of redundant preconditioner contexts.
27109a6bc64SHong Zhang 
27209a6bc64SHong Zhang    Collective on PC
27309a6bc64SHong Zhang 
27409a6bc64SHong Zhang    Input Parameters:
27509a6bc64SHong Zhang +  pc - the preconditioner context
2769b21d695SBarry Smith -  nredundant - number of redundant preconditioner contexts; for example if you are using 64 MPI processes and
2779b21d695SBarry Smith                               use an nredundant of 4 there will be 4 parallel solves each on 16 = 64/4 processes.
27809a6bc64SHong Zhang 
27909a6bc64SHong Zhang    Level: advanced
28009a6bc64SHong Zhang 
28109a6bc64SHong Zhang .keywords: PC, redundant solve
28209a6bc64SHong Zhang @*/
28309a6bc64SHong Zhang PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantSetNumber(PC pc,PetscInt nredundant)
28409a6bc64SHong Zhang {
28509a6bc64SHong Zhang   PetscErrorCode ierr,(*f)(PC,PetscInt);
28609a6bc64SHong Zhang 
28709a6bc64SHong Zhang   PetscFunctionBegin;
2880700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
289*65e19b50SBarry Smith   if (nredundant <= 0) SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONG, "num of redundant pc %D must be positive",nredundant);
29009a6bc64SHong Zhang   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCRedundantSetNumber_C",(void (**)(void))&f);CHKERRQ(ierr);
29109a6bc64SHong Zhang   if (f) {
29209a6bc64SHong Zhang     ierr = (*f)(pc,nredundant);CHKERRQ(ierr);
29309a6bc64SHong Zhang   }
29409a6bc64SHong Zhang   PetscFunctionReturn(0);
29509a6bc64SHong Zhang }
29609a6bc64SHong Zhang 
29709a6bc64SHong Zhang EXTERN_C_BEGIN
29809a6bc64SHong Zhang #undef __FUNCT__
2994b9ad928SBarry Smith #define __FUNCT__ "PCRedundantSetScatter_Redundant"
300dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantSetScatter_Redundant(PC pc,VecScatter in,VecScatter out)
3014b9ad928SBarry Smith {
3024b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
303dfbe8321SBarry Smith   PetscErrorCode ierr;
3044b9ad928SBarry Smith 
3054b9ad928SBarry Smith   PetscFunctionBegin;
3064b9ad928SBarry Smith   ierr = PetscObjectReference((PetscObject)in);CHKERRQ(ierr);
307c3122656SLisandro Dalcin   if (red->scatterin) { ierr = VecScatterDestroy(red->scatterin);CHKERRQ(ierr); }
308c3122656SLisandro Dalcin   red->scatterin  = in;
3094b9ad928SBarry Smith   ierr = PetscObjectReference((PetscObject)out);CHKERRQ(ierr);
310c3122656SLisandro Dalcin   if (red->scatterout) { ierr = VecScatterDestroy(red->scatterout);CHKERRQ(ierr); }
311c3122656SLisandro Dalcin   red->scatterout = out;
3124b9ad928SBarry Smith   PetscFunctionReturn(0);
3134b9ad928SBarry Smith }
3144b9ad928SBarry Smith EXTERN_C_END
3154b9ad928SBarry Smith 
3164b9ad928SBarry Smith #undef __FUNCT__
3174b9ad928SBarry Smith #define __FUNCT__ "PCRedundantSetScatter"
3184b9ad928SBarry Smith /*@
3194b9ad928SBarry Smith    PCRedundantSetScatter - Sets the scatter used to copy values into the
3204b9ad928SBarry Smith      redundant local solve and the scatter to move them back into the global
3214b9ad928SBarry Smith      vector.
3224b9ad928SBarry Smith 
3234b9ad928SBarry Smith    Collective on PC
3244b9ad928SBarry Smith 
3254b9ad928SBarry Smith    Input Parameters:
3264b9ad928SBarry Smith +  pc - the preconditioner context
3274b9ad928SBarry Smith .  in - the scatter to move the values in
3284b9ad928SBarry Smith -  out - the scatter to move them out
3294b9ad928SBarry Smith 
3304b9ad928SBarry Smith    Level: advanced
3314b9ad928SBarry Smith 
3324b9ad928SBarry Smith .keywords: PC, redundant solve
3334b9ad928SBarry Smith @*/
334dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantSetScatter(PC pc,VecScatter in,VecScatter out)
3354b9ad928SBarry Smith {
336dfbe8321SBarry Smith   PetscErrorCode ierr,(*f)(PC,VecScatter,VecScatter);
3374b9ad928SBarry Smith 
3384b9ad928SBarry Smith   PetscFunctionBegin;
3390700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
3400700a824SBarry Smith   PetscValidHeaderSpecific(in,VEC_SCATTER_CLASSID,2);
3410700a824SBarry Smith   PetscValidHeaderSpecific(out,VEC_SCATTER_CLASSID,3);
3424b9ad928SBarry Smith   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCRedundantSetScatter_C",(void (**)(void))&f);CHKERRQ(ierr);
3434b9ad928SBarry Smith   if (f) {
3444b9ad928SBarry Smith     ierr = (*f)(pc,in,out);CHKERRQ(ierr);
3454b9ad928SBarry Smith   }
3464b9ad928SBarry Smith   PetscFunctionReturn(0);
3474b9ad928SBarry Smith }
3484b9ad928SBarry Smith 
3494b9ad928SBarry Smith EXTERN_C_BEGIN
3504b9ad928SBarry Smith #undef __FUNCT__
3514b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetPC_Redundant"
352dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetPC_Redundant(PC pc,PC *innerpc)
3534b9ad928SBarry Smith {
3545f06b7aaSBarry Smith   PetscErrorCode ierr;
3554b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
3565f06b7aaSBarry Smith   MPI_Comm       comm,subcomm;
3575f06b7aaSBarry Smith   const char     *prefix;
3584b9ad928SBarry Smith 
3594b9ad928SBarry Smith   PetscFunctionBegin;
3605f06b7aaSBarry Smith   if (!red->psubcomm) {
3615f06b7aaSBarry Smith     ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
3625f06b7aaSBarry Smith     ierr = PetscSubcommCreate(comm,red->nsubcomm,&red->psubcomm);CHKERRQ(ierr);
3635f06b7aaSBarry Smith     ierr = PetscLogObjectMemory(pc,sizeof(PetscSubcomm));CHKERRQ(ierr);
3645f06b7aaSBarry Smith 
3655f06b7aaSBarry Smith     /* create a new PC that processors in each subcomm have copy of */
3665f06b7aaSBarry Smith     subcomm = red->psubcomm->comm;
3675f06b7aaSBarry Smith     ierr = KSPCreate(subcomm,&red->ksp);CHKERRQ(ierr);
3685f06b7aaSBarry Smith     ierr = PetscObjectIncrementTabLevel((PetscObject)red->ksp,(PetscObject)pc,1);CHKERRQ(ierr);
3695f06b7aaSBarry Smith     ierr = PetscLogObjectParent(pc,red->ksp);CHKERRQ(ierr);
3705f06b7aaSBarry Smith     ierr = KSPSetType(red->ksp,KSPPREONLY);CHKERRQ(ierr);
3715f06b7aaSBarry Smith     ierr = KSPGetPC(red->ksp,&red->pc);CHKERRQ(ierr);
3725f06b7aaSBarry Smith     ierr = PCSetType(red->pc,PCLU);CHKERRQ(ierr);
3735f06b7aaSBarry Smith 
3745f06b7aaSBarry Smith     ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
3755f06b7aaSBarry Smith     ierr = KSPSetOptionsPrefix(red->ksp,prefix);CHKERRQ(ierr);
3765f06b7aaSBarry Smith     ierr = KSPAppendOptionsPrefix(red->ksp,"redundant_");CHKERRQ(ierr);
3775f06b7aaSBarry Smith   }
3785f06b7aaSBarry Smith 
3795f06b7aaSBarry Smith   ierr = KSPGetPC(red->ksp,innerpc);CHKERRQ(ierr);
3804b9ad928SBarry Smith   PetscFunctionReturn(0);
3814b9ad928SBarry Smith }
3824b9ad928SBarry Smith EXTERN_C_END
3834b9ad928SBarry Smith 
3844b9ad928SBarry Smith #undef __FUNCT__
3854b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetPC"
3864b9ad928SBarry Smith /*@
3874b9ad928SBarry Smith    PCRedundantGetPC - Gets the sequential PC created by the redundant PC.
3884b9ad928SBarry Smith 
3894b9ad928SBarry Smith    Not Collective
3904b9ad928SBarry Smith 
3914b9ad928SBarry Smith    Input Parameter:
3924b9ad928SBarry Smith .  pc - the preconditioner context
3934b9ad928SBarry Smith 
3944b9ad928SBarry Smith    Output Parameter:
3954b9ad928SBarry Smith .  innerpc - the sequential PC
3964b9ad928SBarry Smith 
3974b9ad928SBarry Smith    Level: advanced
3984b9ad928SBarry Smith 
3994b9ad928SBarry Smith .keywords: PC, redundant solve
4004b9ad928SBarry Smith @*/
401dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetPC(PC pc,PC *innerpc)
4024b9ad928SBarry Smith {
403dfbe8321SBarry Smith   PetscErrorCode ierr,(*f)(PC,PC*);
4044b9ad928SBarry Smith 
4054b9ad928SBarry Smith   PetscFunctionBegin;
4060700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
4074482741eSBarry Smith   PetscValidPointer(innerpc,2);
4084b9ad928SBarry Smith   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCRedundantGetPC_C",(void (**)(void))&f);CHKERRQ(ierr);
4094b9ad928SBarry Smith   if (f) {
4104b9ad928SBarry Smith     ierr = (*f)(pc,innerpc);CHKERRQ(ierr);
4114b9ad928SBarry Smith   }
4124b9ad928SBarry Smith   PetscFunctionReturn(0);
4134b9ad928SBarry Smith }
4144b9ad928SBarry Smith 
4154b9ad928SBarry Smith EXTERN_C_BEGIN
4164b9ad928SBarry Smith #undef __FUNCT__
4174b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetOperators_Redundant"
418dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetOperators_Redundant(PC pc,Mat *mat,Mat *pmat)
4194b9ad928SBarry Smith {
4204b9ad928SBarry Smith   PC_Redundant *red = (PC_Redundant*)pc->data;
4214b9ad928SBarry Smith 
4224b9ad928SBarry Smith   PetscFunctionBegin;
423b3804887SHong Zhang   if (mat)  *mat  = red->pmats;
424b3804887SHong Zhang   if (pmat) *pmat = red->pmats;
4254b9ad928SBarry Smith   PetscFunctionReturn(0);
4264b9ad928SBarry Smith }
4274b9ad928SBarry Smith EXTERN_C_END
4284b9ad928SBarry Smith 
4294b9ad928SBarry Smith #undef __FUNCT__
4304b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetOperators"
4314b9ad928SBarry Smith /*@
4324b9ad928SBarry Smith    PCRedundantGetOperators - gets the sequential matrix and preconditioner matrix
4334b9ad928SBarry Smith 
4344b9ad928SBarry Smith    Not Collective
4354b9ad928SBarry Smith 
4364b9ad928SBarry Smith    Input Parameter:
4374b9ad928SBarry Smith .  pc - the preconditioner context
4384b9ad928SBarry Smith 
4394b9ad928SBarry Smith    Output Parameters:
4404b9ad928SBarry Smith +  mat - the matrix
4414b9ad928SBarry Smith -  pmat - the (possibly different) preconditioner matrix
4424b9ad928SBarry Smith 
4434b9ad928SBarry Smith    Level: advanced
4444b9ad928SBarry Smith 
4454b9ad928SBarry Smith .keywords: PC, redundant solve
4464b9ad928SBarry Smith @*/
447dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetOperators(PC pc,Mat *mat,Mat *pmat)
4484b9ad928SBarry Smith {
449dfbe8321SBarry Smith   PetscErrorCode ierr,(*f)(PC,Mat*,Mat*);
4504b9ad928SBarry Smith 
4514b9ad928SBarry Smith   PetscFunctionBegin;
4520700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
4534482741eSBarry Smith   if (mat)  PetscValidPointer(mat,2);
4544482741eSBarry Smith   if (pmat) PetscValidPointer(pmat,3);
4554b9ad928SBarry Smith   ierr = PetscObjectQueryFunction((PetscObject)pc,"PCRedundantGetOperators_C",(void (**)(void))&f);CHKERRQ(ierr);
4564b9ad928SBarry Smith   if (f) {
4574b9ad928SBarry Smith     ierr = (*f)(pc,mat,pmat);CHKERRQ(ierr);
4584b9ad928SBarry Smith   }
4594b9ad928SBarry Smith   PetscFunctionReturn(0);
4604b9ad928SBarry Smith }
4614b9ad928SBarry Smith 
4624b9ad928SBarry Smith /* -------------------------------------------------------------------------------------*/
46337a17b4dSBarry Smith /*MC
464a98ce0f4SHong Zhang      PCREDUNDANT - Runs a preconditioner for the entire problem on subgroups of processors
46537a17b4dSBarry Smith 
46637a17b4dSBarry Smith      Options for the redundant preconditioners can be set with -redundant_pc_xxx
46737a17b4dSBarry Smith 
46809391456SBarry Smith   Options Database:
4699b21d695SBarry Smith .  -pc_redundant_number <n> - number of redundant solves, for example if you are using 64 MPI processes and
4709b21d695SBarry Smith                               use an n of 4 there will be 4 parallel solves each on 16 = 64/4 processes.
47109391456SBarry Smith 
47237a17b4dSBarry Smith    Level: intermediate
47337a17b4dSBarry Smith 
47437a17b4dSBarry Smith .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PCRedundantSetScatter(),
4759b21d695SBarry Smith            PCRedundantGetPC(), PCRedundantGetOperators(), PCRedundantSetNumber()
47637a17b4dSBarry Smith M*/
47737a17b4dSBarry Smith 
4784b9ad928SBarry Smith EXTERN_C_BEGIN
4794b9ad928SBarry Smith #undef __FUNCT__
4804b9ad928SBarry Smith #define __FUNCT__ "PCCreate_Redundant"
481dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCCreate_Redundant(PC pc)
4824b9ad928SBarry Smith {
483dfbe8321SBarry Smith   PetscErrorCode ierr;
4844b9ad928SBarry Smith   PC_Redundant   *red;
48569db28dcSHong Zhang   PetscMPIInt    size;
4863f457be1SHong Zhang 
4874b9ad928SBarry Smith   PetscFunctionBegin;
48838f2d2fdSLisandro Dalcin   ierr = PetscNewLog(pc,PC_Redundant,&red);CHKERRQ(ierr);
4897adad957SLisandro Dalcin   ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr);
49069db28dcSHong Zhang   red->nsubcomm       = size;
4914b9ad928SBarry Smith   red->useparallelmat = PETSC_TRUE;
4921fbd8f88SHong Zhang   pc->data            = (void*)red;
4934b9ad928SBarry Smith 
4944b9ad928SBarry Smith   pc->ops->apply           = PCApply_Redundant;
4954b9ad928SBarry Smith   pc->ops->applytranspose  = 0;
4964b9ad928SBarry Smith   pc->ops->setup           = PCSetUp_Redundant;
4974b9ad928SBarry Smith   pc->ops->destroy         = PCDestroy_Redundant;
4984b9ad928SBarry Smith   pc->ops->setfromoptions  = PCSetFromOptions_Redundant;
4994b9ad928SBarry Smith   pc->ops->view            = PCView_Redundant;
5004b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantSetScatter_C","PCRedundantSetScatter_Redundant",
5014b9ad928SBarry Smith                     PCRedundantSetScatter_Redundant);CHKERRQ(ierr);
50209a6bc64SHong Zhang   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantSetNumber_C","PCRedundantSetNumber_Redundant",
50309a6bc64SHong Zhang                     PCRedundantSetNumber_Redundant);CHKERRQ(ierr);
5044b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantGetPC_C","PCRedundantGetPC_Redundant",
5054b9ad928SBarry Smith                     PCRedundantGetPC_Redundant);CHKERRQ(ierr);
5064b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantGetOperators_C","PCRedundantGetOperators_Redundant",
5074b9ad928SBarry Smith                     PCRedundantGetOperators_Redundant);CHKERRQ(ierr);
5084b9ad928SBarry Smith   PetscFunctionReturn(0);
5094b9ad928SBarry Smith }
5104b9ad928SBarry Smith EXTERN_C_END
511