xref: /petsc/src/ksp/pc/impls/redundant/redundant.c (revision 4ac538c5b8a6f410a25710b1290bdbcc3783ea54)
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) */
16ace3abfcSBarry Smith   PetscBool    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;
27ace3abfcSBarry Smith   PetscBool      iascii,isstring;
2803ccd0b4SBarry Smith   PetscViewer    subviewer;
294b9ad928SBarry Smith 
304b9ad928SBarry Smith   PetscFunctionBegin;
312692d6eeSBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
322692d6eeSBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
3332077d6dSBarry Smith   if (iascii) {
3403ccd0b4SBarry Smith     if (!red->psubcomm) {
3503ccd0b4SBarry Smith       ierr = PetscViewerASCIIPrintf(viewer,"  Redundant preconditioner: Not yet setup\n");CHKERRQ(ierr);
3603ccd0b4SBarry Smith     } else {
373e065800SHong Zhang       ierr = PetscViewerASCIIPrintf(viewer,"  Redundant preconditioner: First (color=0) of %D PCs follows\n",red->nsubcomm);CHKERRQ(ierr);
387adad957SLisandro Dalcin       ierr = PetscViewerGetSubcomm(viewer,((PetscObject)red->pc)->comm,&subviewer);CHKERRQ(ierr);
39f5dd71faSBarry Smith       if (!red->psubcomm->color) { /* only view first redundant pc */
404b9ad928SBarry Smith 	ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
413e065800SHong Zhang 	ierr = KSPView(red->ksp,subviewer);CHKERRQ(ierr);
424b9ad928SBarry Smith 	ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
434b9ad928SBarry Smith       }
447adad957SLisandro Dalcin       ierr = PetscViewerRestoreSubcomm(viewer,((PetscObject)red->pc)->comm,&subviewer);CHKERRQ(ierr);
454b9ad928SBarry Smith     }
4603ccd0b4SBarry Smith   } else if (isstring) {
4703ccd0b4SBarry Smith     ierr = PetscViewerStringSPrintf(viewer," Redundant solver preconditioner");CHKERRQ(ierr);
484b9ad928SBarry Smith   } else {
4965e19b50SBarry Smith     SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_SUP,"Viewer type %s not supported for PC redundant",((PetscObject)viewer)->type_name);
504b9ad928SBarry Smith   }
514b9ad928SBarry Smith   PetscFunctionReturn(0);
524b9ad928SBarry Smith }
534b9ad928SBarry Smith 
544b9ad928SBarry Smith #undef __FUNCT__
554b9ad928SBarry Smith #define __FUNCT__ "PCSetUp_Redundant"
566849ba73SBarry Smith static PetscErrorCode PCSetUp_Redundant(PC pc)
574b9ad928SBarry Smith {
584b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
59dfbe8321SBarry Smith   PetscErrorCode ierr;
6045fc02eaSBarry Smith   PetscInt       mstart,mend,mlocal,m,mlocal_sub,rstart_sub,rend_sub,mloc_sub;
6113f74950SBarry Smith   PetscMPIInt    size;
624b9ad928SBarry Smith   MatReuse       reuse = MAT_INITIAL_MATRIX;
634b9ad928SBarry Smith   MatStructure   str = DIFFERENT_NONZERO_PATTERN;
647adad957SLisandro Dalcin   MPI_Comm       comm = ((PetscObject)pc)->comm,subcomm;
6523ce1328SBarry Smith   Vec            vec;
663f457be1SHong Zhang   PetscMPIInt    subsize,subrank;
671fbd8f88SHong Zhang   const char     *prefix;
68b862ddfaSBarry Smith   const PetscInt *range;
693f457be1SHong Zhang 
704b9ad928SBarry Smith   PetscFunctionBegin;
7123ce1328SBarry Smith   ierr = MatGetVecs(pc->pmat,&vec,0);CHKERRQ(ierr);
7223ce1328SBarry Smith   ierr = VecGetSize(vec,&m);CHKERRQ(ierr);
731fbd8f88SHong Zhang 
744b9ad928SBarry Smith   if (!pc->setupcalled) {
755f06b7aaSBarry Smith     if (!red->psubcomm) {
76d8a68f86SHong Zhang       ierr = PetscSubcommCreate(comm,&red->psubcomm);CHKERRQ(ierr);
77d8a68f86SHong Zhang       ierr = PetscSubcommSetNumber(red->psubcomm,red->nsubcomm);CHKERRQ(ierr);
78d8a68f86SHong Zhang       ierr = PetscSubcommSetType(red->psubcomm,PETSC_SUBCOMM_INTERLACED);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       }
13470b3c8c7SBarry Smith       ierr = ISCreateGeneral(comm,red->psubcomm->n*mlocal,idx1,PETSC_COPY_VALUES,&is1);CHKERRQ(ierr);
13570b3c8c7SBarry Smith       ierr = ISCreateGeneral(comm,red->psubcomm->n*mlocal,idx2,PETSC_COPY_VALUES,&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   }
2343e065800SHong Zhang   if (red->ksp) {ierr = KSPDestroy(red->ksp);CHKERRQ(ierr);}
23530ca954eSBarry Smith   if (red->psubcomm) {ierr = PetscSubcommDestroy(red->psubcomm);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 
2723f9fe445SBarry Smith    Logically 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 {
285*4ac538c5SBarry Smith   PetscErrorCode ierr;
28609a6bc64SHong Zhang 
28709a6bc64SHong Zhang   PetscFunctionBegin;
2880700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
28965e19b50SBarry Smith   if (nredundant <= 0) SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONG, "num of redundant pc %D must be positive",nredundant);
290*4ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantSetNumber_C",(PC,PetscInt),(pc,nredundant));CHKERRQ(ierr);
29109a6bc64SHong Zhang   PetscFunctionReturn(0);
29209a6bc64SHong Zhang }
29309a6bc64SHong Zhang 
29409a6bc64SHong Zhang EXTERN_C_BEGIN
29509a6bc64SHong Zhang #undef __FUNCT__
2964b9ad928SBarry Smith #define __FUNCT__ "PCRedundantSetScatter_Redundant"
297dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantSetScatter_Redundant(PC pc,VecScatter in,VecScatter out)
2984b9ad928SBarry Smith {
2994b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
300dfbe8321SBarry Smith   PetscErrorCode ierr;
3014b9ad928SBarry Smith 
3024b9ad928SBarry Smith   PetscFunctionBegin;
3034b9ad928SBarry Smith   ierr = PetscObjectReference((PetscObject)in);CHKERRQ(ierr);
304c3122656SLisandro Dalcin   if (red->scatterin) { ierr = VecScatterDestroy(red->scatterin);CHKERRQ(ierr); }
305c3122656SLisandro Dalcin   red->scatterin  = in;
3064b9ad928SBarry Smith   ierr = PetscObjectReference((PetscObject)out);CHKERRQ(ierr);
307c3122656SLisandro Dalcin   if (red->scatterout) { ierr = VecScatterDestroy(red->scatterout);CHKERRQ(ierr); }
308c3122656SLisandro Dalcin   red->scatterout = out;
3094b9ad928SBarry Smith   PetscFunctionReturn(0);
3104b9ad928SBarry Smith }
3114b9ad928SBarry Smith EXTERN_C_END
3124b9ad928SBarry Smith 
3134b9ad928SBarry Smith #undef __FUNCT__
3144b9ad928SBarry Smith #define __FUNCT__ "PCRedundantSetScatter"
3154b9ad928SBarry Smith /*@
3164b9ad928SBarry Smith    PCRedundantSetScatter - Sets the scatter used to copy values into the
3174b9ad928SBarry Smith      redundant local solve and the scatter to move them back into the global
3184b9ad928SBarry Smith      vector.
3194b9ad928SBarry Smith 
3203f9fe445SBarry Smith    Logically Collective on PC
3214b9ad928SBarry Smith 
3224b9ad928SBarry Smith    Input Parameters:
3234b9ad928SBarry Smith +  pc - the preconditioner context
3244b9ad928SBarry Smith .  in - the scatter to move the values in
3254b9ad928SBarry Smith -  out - the scatter to move them out
3264b9ad928SBarry Smith 
3274b9ad928SBarry Smith    Level: advanced
3284b9ad928SBarry Smith 
3294b9ad928SBarry Smith .keywords: PC, redundant solve
3304b9ad928SBarry Smith @*/
331dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantSetScatter(PC pc,VecScatter in,VecScatter out)
3324b9ad928SBarry Smith {
333*4ac538c5SBarry Smith   PetscErrorCode ierr;
3344b9ad928SBarry Smith 
3354b9ad928SBarry Smith   PetscFunctionBegin;
3360700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
3370700a824SBarry Smith   PetscValidHeaderSpecific(in,VEC_SCATTER_CLASSID,2);
3380700a824SBarry Smith   PetscValidHeaderSpecific(out,VEC_SCATTER_CLASSID,3);
339*4ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantSetScatter_C",(PC,VecScatter,VecScatter),(pc,in,out));CHKERRQ(ierr);
3404b9ad928SBarry Smith   PetscFunctionReturn(0);
3414b9ad928SBarry Smith }
3424b9ad928SBarry Smith 
3434b9ad928SBarry Smith EXTERN_C_BEGIN
3444b9ad928SBarry Smith #undef __FUNCT__
3454b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetPC_Redundant"
346dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetPC_Redundant(PC pc,PC *innerpc)
3474b9ad928SBarry Smith {
3485f06b7aaSBarry Smith   PetscErrorCode ierr;
3494b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
3505f06b7aaSBarry Smith   MPI_Comm       comm,subcomm;
3515f06b7aaSBarry Smith   const char     *prefix;
3524b9ad928SBarry Smith 
3534b9ad928SBarry Smith   PetscFunctionBegin;
3545f06b7aaSBarry Smith   if (!red->psubcomm) {
3555f06b7aaSBarry Smith     ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
356d8a68f86SHong Zhang     ierr = PetscSubcommCreate(comm,&red->psubcomm);CHKERRQ(ierr);
357d8a68f86SHong Zhang     ierr = PetscSubcommSetNumber(red->psubcomm,red->nsubcomm);CHKERRQ(ierr);
358d8a68f86SHong Zhang     ierr = PetscSubcommSetType(red->psubcomm,PETSC_SUBCOMM_INTERLACED);CHKERRQ(ierr);
3595f06b7aaSBarry Smith     ierr = PetscLogObjectMemory(pc,sizeof(PetscSubcomm));CHKERRQ(ierr);
3605f06b7aaSBarry Smith 
3615f06b7aaSBarry Smith     /* create a new PC that processors in each subcomm have copy of */
3625f06b7aaSBarry Smith     subcomm = red->psubcomm->comm;
3635f06b7aaSBarry Smith     ierr = KSPCreate(subcomm,&red->ksp);CHKERRQ(ierr);
3645f06b7aaSBarry Smith     ierr = PetscObjectIncrementTabLevel((PetscObject)red->ksp,(PetscObject)pc,1);CHKERRQ(ierr);
3655f06b7aaSBarry Smith     ierr = PetscLogObjectParent(pc,red->ksp);CHKERRQ(ierr);
3665f06b7aaSBarry Smith     ierr = KSPSetType(red->ksp,KSPPREONLY);CHKERRQ(ierr);
3675f06b7aaSBarry Smith     ierr = KSPGetPC(red->ksp,&red->pc);CHKERRQ(ierr);
3685f06b7aaSBarry Smith     ierr = PCSetType(red->pc,PCLU);CHKERRQ(ierr);
3695f06b7aaSBarry Smith 
3705f06b7aaSBarry Smith     ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
3715f06b7aaSBarry Smith     ierr = KSPSetOptionsPrefix(red->ksp,prefix);CHKERRQ(ierr);
3725f06b7aaSBarry Smith     ierr = KSPAppendOptionsPrefix(red->ksp,"redundant_");CHKERRQ(ierr);
3735f06b7aaSBarry Smith   }
3745f06b7aaSBarry Smith 
3755f06b7aaSBarry Smith   ierr = KSPGetPC(red->ksp,innerpc);CHKERRQ(ierr);
3764b9ad928SBarry Smith   PetscFunctionReturn(0);
3774b9ad928SBarry Smith }
3784b9ad928SBarry Smith EXTERN_C_END
3794b9ad928SBarry Smith 
3804b9ad928SBarry Smith #undef __FUNCT__
3814b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetPC"
3824b9ad928SBarry Smith /*@
3834b9ad928SBarry Smith    PCRedundantGetPC - Gets the sequential PC created by the redundant PC.
3844b9ad928SBarry Smith 
3854b9ad928SBarry Smith    Not Collective
3864b9ad928SBarry Smith 
3874b9ad928SBarry Smith    Input Parameter:
3884b9ad928SBarry Smith .  pc - the preconditioner context
3894b9ad928SBarry Smith 
3904b9ad928SBarry Smith    Output Parameter:
3914b9ad928SBarry Smith .  innerpc - the sequential PC
3924b9ad928SBarry Smith 
3934b9ad928SBarry Smith    Level: advanced
3944b9ad928SBarry Smith 
3954b9ad928SBarry Smith .keywords: PC, redundant solve
3964b9ad928SBarry Smith @*/
397dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetPC(PC pc,PC *innerpc)
3984b9ad928SBarry Smith {
399*4ac538c5SBarry Smith   PetscErrorCode ierr;
4004b9ad928SBarry Smith 
4014b9ad928SBarry Smith   PetscFunctionBegin;
4020700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
4034482741eSBarry Smith   PetscValidPointer(innerpc,2);
404*4ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantGetPC_C",(PC,PC*),(pc,innerpc));CHKERRQ(ierr);
4054b9ad928SBarry Smith   PetscFunctionReturn(0);
4064b9ad928SBarry Smith }
4074b9ad928SBarry Smith 
4084b9ad928SBarry Smith EXTERN_C_BEGIN
4094b9ad928SBarry Smith #undef __FUNCT__
4104b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetOperators_Redundant"
411dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetOperators_Redundant(PC pc,Mat *mat,Mat *pmat)
4124b9ad928SBarry Smith {
4134b9ad928SBarry Smith   PC_Redundant *red = (PC_Redundant*)pc->data;
4144b9ad928SBarry Smith 
4154b9ad928SBarry Smith   PetscFunctionBegin;
416b3804887SHong Zhang   if (mat)  *mat  = red->pmats;
417b3804887SHong Zhang   if (pmat) *pmat = red->pmats;
4184b9ad928SBarry Smith   PetscFunctionReturn(0);
4194b9ad928SBarry Smith }
4204b9ad928SBarry Smith EXTERN_C_END
4214b9ad928SBarry Smith 
4224b9ad928SBarry Smith #undef __FUNCT__
4234b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetOperators"
4244b9ad928SBarry Smith /*@
4254b9ad928SBarry Smith    PCRedundantGetOperators - gets the sequential matrix and preconditioner matrix
4264b9ad928SBarry Smith 
4274b9ad928SBarry Smith    Not Collective
4284b9ad928SBarry Smith 
4294b9ad928SBarry Smith    Input Parameter:
4304b9ad928SBarry Smith .  pc - the preconditioner context
4314b9ad928SBarry Smith 
4324b9ad928SBarry Smith    Output Parameters:
4334b9ad928SBarry Smith +  mat - the matrix
4344b9ad928SBarry Smith -  pmat - the (possibly different) preconditioner matrix
4354b9ad928SBarry Smith 
4364b9ad928SBarry Smith    Level: advanced
4374b9ad928SBarry Smith 
4384b9ad928SBarry Smith .keywords: PC, redundant solve
4394b9ad928SBarry Smith @*/
440dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCRedundantGetOperators(PC pc,Mat *mat,Mat *pmat)
4414b9ad928SBarry Smith {
442*4ac538c5SBarry Smith   PetscErrorCode ierr;
4434b9ad928SBarry Smith 
4444b9ad928SBarry Smith   PetscFunctionBegin;
4450700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
4464482741eSBarry Smith   if (mat)  PetscValidPointer(mat,2);
4474482741eSBarry Smith   if (pmat) PetscValidPointer(pmat,3);
448*4ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantGetOperators_C",(PC,Mat*,Mat*),(pc,mat,pmat));CHKERRQ(ierr);
4494b9ad928SBarry Smith   PetscFunctionReturn(0);
4504b9ad928SBarry Smith }
4514b9ad928SBarry Smith 
4524b9ad928SBarry Smith /* -------------------------------------------------------------------------------------*/
45337a17b4dSBarry Smith /*MC
454a98ce0f4SHong Zhang      PCREDUNDANT - Runs a preconditioner for the entire problem on subgroups of processors
45537a17b4dSBarry Smith 
45637a17b4dSBarry Smith      Options for the redundant preconditioners can be set with -redundant_pc_xxx
45737a17b4dSBarry Smith 
45809391456SBarry Smith   Options Database:
4599b21d695SBarry Smith .  -pc_redundant_number <n> - number of redundant solves, for example if you are using 64 MPI processes and
4609b21d695SBarry Smith                               use an n of 4 there will be 4 parallel solves each on 16 = 64/4 processes.
46109391456SBarry Smith 
46237a17b4dSBarry Smith    Level: intermediate
46337a17b4dSBarry Smith 
46437a17b4dSBarry Smith .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PCRedundantSetScatter(),
4659b21d695SBarry Smith            PCRedundantGetPC(), PCRedundantGetOperators(), PCRedundantSetNumber()
46637a17b4dSBarry Smith M*/
46737a17b4dSBarry Smith 
4684b9ad928SBarry Smith EXTERN_C_BEGIN
4694b9ad928SBarry Smith #undef __FUNCT__
4704b9ad928SBarry Smith #define __FUNCT__ "PCCreate_Redundant"
471dba47a55SKris Buschelman PetscErrorCode PETSCKSP_DLLEXPORT PCCreate_Redundant(PC pc)
4724b9ad928SBarry Smith {
473dfbe8321SBarry Smith   PetscErrorCode ierr;
4744b9ad928SBarry Smith   PC_Redundant   *red;
47569db28dcSHong Zhang   PetscMPIInt    size;
4763f457be1SHong Zhang 
4774b9ad928SBarry Smith   PetscFunctionBegin;
47838f2d2fdSLisandro Dalcin   ierr = PetscNewLog(pc,PC_Redundant,&red);CHKERRQ(ierr);
4797adad957SLisandro Dalcin   ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr);
48069db28dcSHong Zhang   red->nsubcomm       = size;
4814b9ad928SBarry Smith   red->useparallelmat = PETSC_TRUE;
4821fbd8f88SHong Zhang   pc->data            = (void*)red;
4834b9ad928SBarry Smith 
4844b9ad928SBarry Smith   pc->ops->apply           = PCApply_Redundant;
4854b9ad928SBarry Smith   pc->ops->applytranspose  = 0;
4864b9ad928SBarry Smith   pc->ops->setup           = PCSetUp_Redundant;
4874b9ad928SBarry Smith   pc->ops->destroy         = PCDestroy_Redundant;
4884b9ad928SBarry Smith   pc->ops->setfromoptions  = PCSetFromOptions_Redundant;
4894b9ad928SBarry Smith   pc->ops->view            = PCView_Redundant;
4904b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantSetScatter_C","PCRedundantSetScatter_Redundant",
4914b9ad928SBarry Smith                     PCRedundantSetScatter_Redundant);CHKERRQ(ierr);
49209a6bc64SHong Zhang   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantSetNumber_C","PCRedundantSetNumber_Redundant",
49309a6bc64SHong Zhang                     PCRedundantSetNumber_Redundant);CHKERRQ(ierr);
4944b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantGetPC_C","PCRedundantGetPC_Redundant",
4954b9ad928SBarry Smith                     PCRedundantGetPC_Redundant);CHKERRQ(ierr);
4964b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantGetOperators_C","PCRedundantGetOperators_Redundant",
4974b9ad928SBarry Smith                     PCRedundantGetOperators_Redundant);CHKERRQ(ierr);
4984b9ad928SBarry Smith   PetscFunctionReturn(0);
4994b9ad928SBarry Smith }
5004b9ad928SBarry Smith EXTERN_C_END
501