xref: /petsc/src/ksp/pc/impls/redundant/redundant.c (revision 546c30cbfe2d3ec3a3afa0dcf51ab41d2326a062)
1dba47a55SKris Buschelman 
24b9ad928SBarry Smith /*
33f457be1SHong Zhang   This file defines a "solve the problem redundantly on each subgroup of processor" preconditioner.
44b9ad928SBarry Smith */
5c6db04a5SJed Brown #include <private/pcimpl.h>     /*I "petscpc.h" I*/
6c6db04a5SJed Brown #include <petscksp.h>           /*I "petscksp.h" I*/
74b9ad928SBarry Smith 
84b9ad928SBarry Smith typedef struct {
93e065800SHong Zhang   KSP          ksp;
104b9ad928SBarry Smith   PC           pc;                   /* actual preconditioner used on each processor */
117adad957SLisandro Dalcin   Vec          xsub,ysub;            /* vectors of a subcommunicator to hold parallel vectors of ((PetscObject)pc)->comm */
123f457be1SHong Zhang   Vec          xdup,ydup;            /* parallel vector that congregates xsub or ysub facilitating vector scattering */
13b3804887SHong Zhang   Mat          pmats;                /* matrix and optional preconditioner matrix belong to a subcommunicator */
143f457be1SHong Zhang   VecScatter   scatterin,scatterout; /* scatter used to move all values to each processor group (subcommunicator) */
15ace3abfcSBarry Smith   PetscBool    useparallelmat;
16c540e29cSHong Zhang   PetscSubcomm psubcomm;
171fbd8f88SHong Zhang   PetscInt     nsubcomm;           /* num of data structure PetscSubcomm */
184b9ad928SBarry Smith } PC_Redundant;
194b9ad928SBarry Smith 
204b9ad928SBarry Smith #undef __FUNCT__
214b9ad928SBarry Smith #define __FUNCT__ "PCView_Redundant"
226849ba73SBarry Smith static PetscErrorCode PCView_Redundant(PC pc,PetscViewer viewer)
234b9ad928SBarry Smith {
244b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
25dfbe8321SBarry Smith   PetscErrorCode ierr;
26ace3abfcSBarry Smith   PetscBool      iascii,isstring;
2703ccd0b4SBarry Smith   PetscViewer    subviewer;
284b9ad928SBarry Smith 
294b9ad928SBarry Smith   PetscFunctionBegin;
302692d6eeSBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
312692d6eeSBarry Smith   ierr = PetscTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
3232077d6dSBarry Smith   if (iascii) {
3303ccd0b4SBarry Smith     if (!red->psubcomm) {
3403ccd0b4SBarry Smith       ierr = PetscViewerASCIIPrintf(viewer,"  Redundant preconditioner: Not yet setup\n");CHKERRQ(ierr);
3503ccd0b4SBarry Smith     } else {
363e065800SHong Zhang       ierr = PetscViewerASCIIPrintf(viewer,"  Redundant preconditioner: First (color=0) of %D PCs follows\n",red->nsubcomm);CHKERRQ(ierr);
377adad957SLisandro Dalcin       ierr = PetscViewerGetSubcomm(viewer,((PetscObject)red->pc)->comm,&subviewer);CHKERRQ(ierr);
38f5dd71faSBarry Smith       if (!red->psubcomm->color) { /* only view first redundant pc */
394b9ad928SBarry Smith 	ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
403e065800SHong Zhang 	ierr = KSPView(red->ksp,subviewer);CHKERRQ(ierr);
414b9ad928SBarry Smith 	ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
424b9ad928SBarry Smith       }
437adad957SLisandro Dalcin       ierr = PetscViewerRestoreSubcomm(viewer,((PetscObject)red->pc)->comm,&subviewer);CHKERRQ(ierr);
444b9ad928SBarry Smith     }
4503ccd0b4SBarry Smith   } else if (isstring) {
4603ccd0b4SBarry Smith     ierr = PetscViewerStringSPrintf(viewer," Redundant solver preconditioner");CHKERRQ(ierr);
474b9ad928SBarry Smith   } else {
4865e19b50SBarry Smith     SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_SUP,"Viewer type %s not supported for PC redundant",((PetscObject)viewer)->type_name);
494b9ad928SBarry Smith   }
504b9ad928SBarry Smith   PetscFunctionReturn(0);
514b9ad928SBarry Smith }
524b9ad928SBarry Smith 
534b9ad928SBarry Smith #undef __FUNCT__
544b9ad928SBarry Smith #define __FUNCT__ "PCSetUp_Redundant"
556849ba73SBarry Smith static PetscErrorCode PCSetUp_Redundant(PC pc)
564b9ad928SBarry Smith {
574b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
58dfbe8321SBarry Smith   PetscErrorCode ierr;
5945fc02eaSBarry Smith   PetscInt       mstart,mend,mlocal,m,mlocal_sub,rstart_sub,rend_sub,mloc_sub;
6013f74950SBarry Smith   PetscMPIInt    size;
614b9ad928SBarry Smith   MatReuse       reuse = MAT_INITIAL_MATRIX;
624b9ad928SBarry Smith   MatStructure   str = DIFFERENT_NONZERO_PATTERN;
637adad957SLisandro Dalcin   MPI_Comm       comm = ((PetscObject)pc)->comm,subcomm;
6423ce1328SBarry Smith   Vec            vec;
653f457be1SHong Zhang   PetscMPIInt    subsize,subrank;
661fbd8f88SHong Zhang   const char     *prefix;
67b862ddfaSBarry Smith   const PetscInt *range;
683f457be1SHong Zhang 
694b9ad928SBarry Smith   PetscFunctionBegin;
7023ce1328SBarry Smith   ierr = MatGetVecs(pc->pmat,&vec,0);CHKERRQ(ierr);
7123ce1328SBarry Smith   ierr = VecGetSize(vec,&m);CHKERRQ(ierr);
721fbd8f88SHong Zhang 
734b9ad928SBarry Smith   if (!pc->setupcalled) {
745f06b7aaSBarry Smith     if (!red->psubcomm) {
75d8a68f86SHong Zhang       ierr = PetscSubcommCreate(comm,&red->psubcomm);CHKERRQ(ierr);
76d8a68f86SHong Zhang       ierr = PetscSubcommSetNumber(red->psubcomm,red->nsubcomm);CHKERRQ(ierr);
77d8a68f86SHong Zhang       ierr = PetscSubcommSetType(red->psubcomm,PETSC_SUBCOMM_INTERLACED);CHKERRQ(ierr);
781fbd8f88SHong Zhang       ierr = PetscLogObjectMemory(pc,sizeof(PetscSubcomm));CHKERRQ(ierr);
791fbd8f88SHong Zhang 
801fbd8f88SHong Zhang       /* create a new PC that processors in each subcomm have copy of */
810d7810c8SBarry Smith       subcomm = red->psubcomm->comm;
825f06b7aaSBarry Smith       ierr = KSPCreate(subcomm,&red->ksp);CHKERRQ(ierr);
835f06b7aaSBarry Smith       ierr = PetscObjectIncrementTabLevel((PetscObject)red->ksp,(PetscObject)pc,1);CHKERRQ(ierr);
845f06b7aaSBarry Smith       ierr = PetscLogObjectParent(pc,red->ksp);CHKERRQ(ierr);
855f06b7aaSBarry Smith       ierr = KSPSetType(red->ksp,KSPPREONLY);CHKERRQ(ierr);
865f06b7aaSBarry Smith       ierr = KSPGetPC(red->ksp,&red->pc);CHKERRQ(ierr);
87cf52b8b1SHong Zhang       ierr = PCSetType(red->pc,PCLU);CHKERRQ(ierr);
88cf52b8b1SHong Zhang 
891fbd8f88SHong Zhang       ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
905f06b7aaSBarry Smith       ierr = KSPSetOptionsPrefix(red->ksp,prefix);CHKERRQ(ierr);
915f06b7aaSBarry Smith       ierr = KSPAppendOptionsPrefix(red->ksp,"redundant_");CHKERRQ(ierr);
925f06b7aaSBarry Smith     } else {
935f06b7aaSBarry Smith        subcomm = red->psubcomm->comm;
945f06b7aaSBarry Smith     }
951fbd8f88SHong Zhang 
963f457be1SHong Zhang     /* create working vectors xsub/ysub and xdup/ydup */
9723ce1328SBarry Smith     ierr = VecGetLocalSize(vec,&mlocal);CHKERRQ(ierr);
983f457be1SHong Zhang     ierr = VecGetOwnershipRange(vec,&mstart,&mend);CHKERRQ(ierr);
994b9ad928SBarry Smith 
1003f457be1SHong Zhang     /* get local size of xsub/ysub */
1011fbd8f88SHong Zhang     ierr = MPI_Comm_size(subcomm,&subsize);CHKERRQ(ierr);
1021fbd8f88SHong Zhang     ierr = MPI_Comm_rank(subcomm,&subrank);CHKERRQ(ierr);
103b862ddfaSBarry Smith     ierr = MatGetOwnershipRanges(pc->pmat,&range);CHKERRQ(ierr);
104b862ddfaSBarry Smith     rstart_sub = range[red->psubcomm->n*subrank]; /* rstart in xsub/ysub */
1053f457be1SHong Zhang     if (subrank+1 < subsize){
106b862ddfaSBarry Smith       rend_sub = range[red->psubcomm->n*(subrank+1)];
1073f457be1SHong Zhang     } else {
1083f457be1SHong Zhang       rend_sub = m;
1093f457be1SHong Zhang     }
1103f457be1SHong Zhang     mloc_sub = rend_sub - rstart_sub;
1111fbd8f88SHong Zhang     ierr = VecCreateMPI(subcomm,mloc_sub,PETSC_DECIDE,&red->ysub);CHKERRQ(ierr);
1123f457be1SHong Zhang     /* create xsub with empty local arrays, because xdup's arrays will be placed into it */
1131fbd8f88SHong Zhang     ierr = VecCreateMPIWithArray(subcomm,mloc_sub,PETSC_DECIDE,PETSC_NULL,&red->xsub);CHKERRQ(ierr);
1143f457be1SHong Zhang 
1153f457be1SHong Zhang     /* create xdup and ydup. ydup has empty local arrays because ysub's arrays will be place into it.
1167adad957SLisandro Dalcin        Note: we use communicator dupcomm, not ((PetscObject)pc)->comm! */
1171fbd8f88SHong Zhang     ierr = VecCreateMPI(red->psubcomm->dupparent,mloc_sub,PETSC_DECIDE,&red->xdup);CHKERRQ(ierr);
1181fbd8f88SHong Zhang     ierr = VecCreateMPIWithArray(red->psubcomm->dupparent,mloc_sub,PETSC_DECIDE,PETSC_NULL,&red->ydup);CHKERRQ(ierr);
1193f457be1SHong Zhang 
1203f457be1SHong Zhang     /* create vec scatters */
1213f457be1SHong Zhang     if (!red->scatterin){
1223f457be1SHong Zhang       IS       is1,is2;
1233f457be1SHong Zhang       PetscInt *idx1,*idx2,i,j,k;
12445fc02eaSBarry Smith 
1251d79065fSBarry Smith       ierr = PetscMalloc2(red->psubcomm->n*mlocal,PetscInt,&idx1,red->psubcomm->n*mlocal,PetscInt,&idx2);CHKERRQ(ierr);
1263f457be1SHong Zhang       j = 0;
1271fbd8f88SHong Zhang       for (k=0; k<red->psubcomm->n; k++){
1283f457be1SHong Zhang         for (i=mstart; i<mend; i++){
1293f457be1SHong Zhang           idx1[j]   = i;
1303f457be1SHong Zhang           idx2[j++] = i + m*k;
1313f457be1SHong Zhang         }
1323f457be1SHong Zhang       }
13370b3c8c7SBarry Smith       ierr = ISCreateGeneral(comm,red->psubcomm->n*mlocal,idx1,PETSC_COPY_VALUES,&is1);CHKERRQ(ierr);
13470b3c8c7SBarry Smith       ierr = ISCreateGeneral(comm,red->psubcomm->n*mlocal,idx2,PETSC_COPY_VALUES,&is2);CHKERRQ(ierr);
1353f457be1SHong Zhang       ierr = VecScatterCreate(vec,is1,red->xdup,is2,&red->scatterin);CHKERRQ(ierr);
136fcfd50ebSBarry Smith       ierr = ISDestroy(&is1);CHKERRQ(ierr);
137fcfd50ebSBarry Smith       ierr = ISDestroy(&is2);CHKERRQ(ierr);
1383f457be1SHong Zhang 
1391fbd8f88SHong Zhang       ierr = ISCreateStride(comm,mlocal,mstart+ red->psubcomm->color*m,1,&is1);CHKERRQ(ierr);
1403f457be1SHong Zhang       ierr = ISCreateStride(comm,mlocal,mstart,1,&is2);CHKERRQ(ierr);
1413f457be1SHong Zhang       ierr = VecScatterCreate(red->xdup,is1,vec,is2,&red->scatterout);CHKERRQ(ierr);
142fcfd50ebSBarry Smith       ierr = ISDestroy(&is1);CHKERRQ(ierr);
143fcfd50ebSBarry Smith       ierr = ISDestroy(&is2);CHKERRQ(ierr);
1441d79065fSBarry Smith       ierr = PetscFree2(idx1,idx2);CHKERRQ(ierr);
1454b9ad928SBarry Smith     }
1464b9ad928SBarry Smith   }
1476bf464f9SBarry Smith   ierr = VecDestroy(&vec);CHKERRQ(ierr);
1484b9ad928SBarry Smith 
1494b9ad928SBarry Smith   /* if pmatrix set by user is sequential then we do not need to gather the parallel matrix */
1503f457be1SHong Zhang   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
1514b9ad928SBarry Smith   if (size == 1) {
1524b9ad928SBarry Smith     red->useparallelmat = PETSC_FALSE;
1534b9ad928SBarry Smith   }
1544b9ad928SBarry Smith 
1554b9ad928SBarry Smith   if (red->useparallelmat) {
1564b9ad928SBarry Smith     if (pc->setupcalled == 1 && pc->flag == DIFFERENT_NONZERO_PATTERN) {
1574b9ad928SBarry Smith       /* destroy old matrices */
1586bf464f9SBarry Smith       ierr = MatDestroy(&red->pmats);CHKERRQ(ierr);
1594b9ad928SBarry Smith     } else if (pc->setupcalled == 1) {
1604b9ad928SBarry Smith       reuse = MAT_REUSE_MATRIX;
1614b9ad928SBarry Smith       str   = SAME_NONZERO_PATTERN;
1624b9ad928SBarry Smith     }
1634b9ad928SBarry Smith 
1643f457be1SHong Zhang     /* grab the parallel matrix and put it into processors of a subcomminicator */
165f664ae05SHong Zhang     /*--------------------------------------------------------------------------*/
166f664ae05SHong Zhang     ierr = VecGetLocalSize(red->ysub,&mlocal_sub);CHKERRQ(ierr);
16769db28dcSHong Zhang     ierr = MatGetRedundantMatrix(pc->pmat,red->psubcomm->n,red->psubcomm->comm,mlocal_sub,reuse,&red->pmats);CHKERRQ(ierr);
1683f457be1SHong Zhang     /* tell PC of the subcommunicator its operators */
16990f1c854SHong Zhang     ierr = KSPSetOperators(red->ksp,red->pmats,red->pmats,str);CHKERRQ(ierr);
1704b9ad928SBarry Smith   } else {
17190f1c854SHong Zhang     ierr = KSPSetOperators(red->ksp,pc->mat,pc->pmat,pc->flag);CHKERRQ(ierr);
1724b9ad928SBarry Smith   }
1730c24e6a1SHong Zhang   if (pc->setfromoptionscalled){
1743e065800SHong Zhang     ierr = KSPSetFromOptions(red->ksp);CHKERRQ(ierr);
1750c24e6a1SHong Zhang   }
1763e065800SHong Zhang   ierr = KSPSetUp(red->ksp);CHKERRQ(ierr);
1774b9ad928SBarry Smith   PetscFunctionReturn(0);
1784b9ad928SBarry Smith }
1794b9ad928SBarry Smith 
1804b9ad928SBarry Smith #undef __FUNCT__
1814b9ad928SBarry Smith #define __FUNCT__ "PCApply_Redundant"
1826849ba73SBarry Smith static PetscErrorCode PCApply_Redundant(PC pc,Vec x,Vec y)
1834b9ad928SBarry Smith {
1844b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
185dfbe8321SBarry Smith   PetscErrorCode ierr;
1863f457be1SHong Zhang   PetscScalar    *array;
1874b9ad928SBarry Smith 
1884b9ad928SBarry Smith   PetscFunctionBegin;
1893f457be1SHong Zhang   /* scatter x to xdup */
190ca9f406cSSatish Balay   ierr = VecScatterBegin(red->scatterin,x,red->xdup,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
191ca9f406cSSatish Balay   ierr = VecScatterEnd(red->scatterin,x,red->xdup,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
1923f457be1SHong Zhang 
1933f457be1SHong Zhang   /* place xdup's local array into xsub */
1943f457be1SHong Zhang   ierr = VecGetArray(red->xdup,&array);CHKERRQ(ierr);
1953f457be1SHong Zhang   ierr = VecPlaceArray(red->xsub,(const PetscScalar*)array);CHKERRQ(ierr);
1964b9ad928SBarry Smith 
1974b9ad928SBarry Smith   /* apply preconditioner on each processor */
19883ab6a24SBarry Smith   ierr = KSPSolve(red->ksp,red->xsub,red->ysub);CHKERRQ(ierr);
1993f457be1SHong Zhang   ierr = VecResetArray(red->xsub);CHKERRQ(ierr);
2003f457be1SHong Zhang   ierr = VecRestoreArray(red->xdup,&array);CHKERRQ(ierr);
2014b9ad928SBarry Smith 
2023f457be1SHong Zhang   /* place ysub's local array into ydup */
2033f457be1SHong Zhang   ierr = VecGetArray(red->ysub,&array);CHKERRQ(ierr);
2043f457be1SHong Zhang   ierr = VecPlaceArray(red->ydup,(const PetscScalar*)array);CHKERRQ(ierr);
2053f457be1SHong Zhang 
2063f457be1SHong Zhang   /* scatter ydup to y */
207ca9f406cSSatish Balay   ierr = VecScatterBegin(red->scatterout,red->ydup,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
208ca9f406cSSatish Balay   ierr = VecScatterEnd(red->scatterout,red->ydup,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
2093f457be1SHong Zhang   ierr = VecResetArray(red->ydup);CHKERRQ(ierr);
2103f457be1SHong Zhang   ierr = VecRestoreArray(red->ysub,&array);CHKERRQ(ierr);
2114b9ad928SBarry Smith   PetscFunctionReturn(0);
2124b9ad928SBarry Smith }
2134b9ad928SBarry Smith 
2144b9ad928SBarry Smith #undef __FUNCT__
2151ea5a559SBarry Smith #define __FUNCT__ "PCReset_Redundant"
2161ea5a559SBarry Smith static PetscErrorCode PCReset_Redundant(PC pc)
2174b9ad928SBarry Smith {
2184b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
219dfbe8321SBarry Smith   PetscErrorCode ierr;
2204b9ad928SBarry Smith 
2214b9ad928SBarry Smith   PetscFunctionBegin;
2226bf464f9SBarry Smith   ierr = VecScatterDestroy(&red->scatterin);CHKERRQ(ierr);
2236bf464f9SBarry Smith   ierr = VecScatterDestroy(&red->scatterout);CHKERRQ(ierr);
2246bf464f9SBarry Smith   ierr = VecDestroy(&red->ysub);CHKERRQ(ierr);
2256bf464f9SBarry Smith   ierr = VecDestroy(&red->xsub);CHKERRQ(ierr);
2266bf464f9SBarry Smith   ierr = VecDestroy(&red->xdup);CHKERRQ(ierr);
2276bf464f9SBarry Smith   ierr = VecDestroy(&red->ydup);CHKERRQ(ierr);
2286bf464f9SBarry Smith   ierr = MatDestroy(&red->pmats);CHKERRQ(ierr);
229*546c30cbSLisandro Dalcin   if (red->ksp) {ierr = KSPReset(red->ksp);CHKERRQ(ierr);}
2301ea5a559SBarry Smith   PetscFunctionReturn(0);
2311ea5a559SBarry Smith }
2321ea5a559SBarry Smith 
2331ea5a559SBarry Smith #undef __FUNCT__
2341ea5a559SBarry Smith #define __FUNCT__ "PCDestroy_Redundant"
2351ea5a559SBarry Smith static PetscErrorCode PCDestroy_Redundant(PC pc)
2361ea5a559SBarry Smith {
2371ea5a559SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
2381ea5a559SBarry Smith   PetscErrorCode ierr;
2391ea5a559SBarry Smith 
2401ea5a559SBarry Smith   PetscFunctionBegin;
2411ea5a559SBarry Smith   ierr = PCReset_Redundant(pc);CHKERRQ(ierr);
2426bf464f9SBarry Smith   ierr = KSPDestroy(&red->ksp);CHKERRQ(ierr);
2436bf464f9SBarry Smith   ierr = PetscSubcommDestroy(&red->psubcomm);CHKERRQ(ierr);
244c31cb41cSBarry Smith   ierr = PetscFree(pc->data);CHKERRQ(ierr);
2454b9ad928SBarry Smith   PetscFunctionReturn(0);
2464b9ad928SBarry Smith }
2474b9ad928SBarry Smith 
2484b9ad928SBarry Smith #undef __FUNCT__
2494b9ad928SBarry Smith #define __FUNCT__ "PCSetFromOptions_Redundant"
2506849ba73SBarry Smith static PetscErrorCode PCSetFromOptions_Redundant(PC pc)
2514b9ad928SBarry Smith {
252a98ce0f4SHong Zhang   PetscErrorCode ierr;
253a98ce0f4SHong Zhang   PC_Redundant   *red = (PC_Redundant*)pc->data;
254a98ce0f4SHong Zhang 
2554b9ad928SBarry Smith   PetscFunctionBegin;
256a98ce0f4SHong Zhang   ierr = PetscOptionsHead("Redundant options");CHKERRQ(ierr);
25709a6bc64SHong Zhang   ierr = PetscOptionsInt("-pc_redundant_number","Number of redundant pc","PCRedundantSetNumber",red->nsubcomm,&red->nsubcomm,0);CHKERRQ(ierr);
258a98ce0f4SHong Zhang   ierr = PetscOptionsTail();CHKERRQ(ierr);
2594b9ad928SBarry Smith   PetscFunctionReturn(0);
2604b9ad928SBarry Smith }
2614b9ad928SBarry Smith 
2624b9ad928SBarry Smith EXTERN_C_BEGIN
2634b9ad928SBarry Smith #undef __FUNCT__
26409a6bc64SHong Zhang #define __FUNCT__ "PCRedundantSetNumber_Redundant"
2657087cfbeSBarry Smith PetscErrorCode  PCRedundantSetNumber_Redundant(PC pc,PetscInt nreds)
26609a6bc64SHong Zhang {
26709a6bc64SHong Zhang   PC_Redundant *red = (PC_Redundant*)pc->data;
26809a6bc64SHong Zhang 
26909a6bc64SHong Zhang   PetscFunctionBegin;
27009a6bc64SHong Zhang   red->nsubcomm = nreds;
27109a6bc64SHong Zhang   PetscFunctionReturn(0);
27209a6bc64SHong Zhang }
27309a6bc64SHong Zhang EXTERN_C_END
27409a6bc64SHong Zhang 
27509a6bc64SHong Zhang #undef __FUNCT__
27609a6bc64SHong Zhang #define __FUNCT__ "PCRedundantSetNumber"
27709a6bc64SHong Zhang /*@
27809a6bc64SHong Zhang    PCRedundantSetNumber - Sets the number of redundant preconditioner contexts.
27909a6bc64SHong Zhang 
2803f9fe445SBarry Smith    Logically Collective on PC
28109a6bc64SHong Zhang 
28209a6bc64SHong Zhang    Input Parameters:
28309a6bc64SHong Zhang +  pc - the preconditioner context
2849b21d695SBarry Smith -  nredundant - number of redundant preconditioner contexts; for example if you are using 64 MPI processes and
2859b21d695SBarry Smith                               use an nredundant of 4 there will be 4 parallel solves each on 16 = 64/4 processes.
28609a6bc64SHong Zhang 
28709a6bc64SHong Zhang    Level: advanced
28809a6bc64SHong Zhang 
28909a6bc64SHong Zhang .keywords: PC, redundant solve
29009a6bc64SHong Zhang @*/
2917087cfbeSBarry Smith PetscErrorCode  PCRedundantSetNumber(PC pc,PetscInt nredundant)
29209a6bc64SHong Zhang {
2934ac538c5SBarry Smith   PetscErrorCode ierr;
29409a6bc64SHong Zhang 
29509a6bc64SHong Zhang   PetscFunctionBegin;
2960700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
29765e19b50SBarry Smith   if (nredundant <= 0) SETERRQ1(((PetscObject)pc)->comm,PETSC_ERR_ARG_WRONG, "num of redundant pc %D must be positive",nredundant);
2984ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantSetNumber_C",(PC,PetscInt),(pc,nredundant));CHKERRQ(ierr);
29909a6bc64SHong Zhang   PetscFunctionReturn(0);
30009a6bc64SHong Zhang }
30109a6bc64SHong Zhang 
30209a6bc64SHong Zhang EXTERN_C_BEGIN
30309a6bc64SHong Zhang #undef __FUNCT__
3044b9ad928SBarry Smith #define __FUNCT__ "PCRedundantSetScatter_Redundant"
3057087cfbeSBarry Smith PetscErrorCode  PCRedundantSetScatter_Redundant(PC pc,VecScatter in,VecScatter out)
3064b9ad928SBarry Smith {
3074b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
308dfbe8321SBarry Smith   PetscErrorCode ierr;
3094b9ad928SBarry Smith 
3104b9ad928SBarry Smith   PetscFunctionBegin;
3114b9ad928SBarry Smith   ierr = PetscObjectReference((PetscObject)in);CHKERRQ(ierr);
3126bf464f9SBarry Smith   ierr = VecScatterDestroy(&red->scatterin);CHKERRQ(ierr);
313c3122656SLisandro Dalcin   red->scatterin  = in;
3144b9ad928SBarry Smith   ierr = PetscObjectReference((PetscObject)out);CHKERRQ(ierr);
3156bf464f9SBarry Smith   ierr = VecScatterDestroy(&red->scatterout);CHKERRQ(ierr);
316c3122656SLisandro Dalcin   red->scatterout = out;
3174b9ad928SBarry Smith   PetscFunctionReturn(0);
3184b9ad928SBarry Smith }
3194b9ad928SBarry Smith EXTERN_C_END
3204b9ad928SBarry Smith 
3214b9ad928SBarry Smith #undef __FUNCT__
3224b9ad928SBarry Smith #define __FUNCT__ "PCRedundantSetScatter"
3234b9ad928SBarry Smith /*@
3244b9ad928SBarry Smith    PCRedundantSetScatter - Sets the scatter used to copy values into the
3254b9ad928SBarry Smith      redundant local solve and the scatter to move them back into the global
3264b9ad928SBarry Smith      vector.
3274b9ad928SBarry Smith 
3283f9fe445SBarry Smith    Logically Collective on PC
3294b9ad928SBarry Smith 
3304b9ad928SBarry Smith    Input Parameters:
3314b9ad928SBarry Smith +  pc - the preconditioner context
3324b9ad928SBarry Smith .  in - the scatter to move the values in
3334b9ad928SBarry Smith -  out - the scatter to move them out
3344b9ad928SBarry Smith 
3354b9ad928SBarry Smith    Level: advanced
3364b9ad928SBarry Smith 
3374b9ad928SBarry Smith .keywords: PC, redundant solve
3384b9ad928SBarry Smith @*/
3397087cfbeSBarry Smith PetscErrorCode  PCRedundantSetScatter(PC pc,VecScatter in,VecScatter out)
3404b9ad928SBarry Smith {
3414ac538c5SBarry Smith   PetscErrorCode ierr;
3424b9ad928SBarry Smith 
3434b9ad928SBarry Smith   PetscFunctionBegin;
3440700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
3450700a824SBarry Smith   PetscValidHeaderSpecific(in,VEC_SCATTER_CLASSID,2);
3460700a824SBarry Smith   PetscValidHeaderSpecific(out,VEC_SCATTER_CLASSID,3);
3474ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantSetScatter_C",(PC,VecScatter,VecScatter),(pc,in,out));CHKERRQ(ierr);
3484b9ad928SBarry Smith   PetscFunctionReturn(0);
3494b9ad928SBarry Smith }
3504b9ad928SBarry Smith 
3514b9ad928SBarry Smith EXTERN_C_BEGIN
3524b9ad928SBarry Smith #undef __FUNCT__
35383ab6a24SBarry Smith #define __FUNCT__ "PCRedundantGetKSP_Redundant"
35483ab6a24SBarry Smith PetscErrorCode  PCRedundantGetKSP_Redundant(PC pc,KSP *innerksp)
3554b9ad928SBarry Smith {
3565f06b7aaSBarry Smith   PetscErrorCode ierr;
3574b9ad928SBarry Smith   PC_Redundant   *red = (PC_Redundant*)pc->data;
3585f06b7aaSBarry Smith   MPI_Comm       comm,subcomm;
3595f06b7aaSBarry Smith   const char     *prefix;
3604b9ad928SBarry Smith 
3614b9ad928SBarry Smith   PetscFunctionBegin;
3625f06b7aaSBarry Smith   if (!red->psubcomm) {
3635f06b7aaSBarry Smith     ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr);
364d8a68f86SHong Zhang     ierr = PetscSubcommCreate(comm,&red->psubcomm);CHKERRQ(ierr);
365d8a68f86SHong Zhang     ierr = PetscSubcommSetNumber(red->psubcomm,red->nsubcomm);CHKERRQ(ierr);
366d8a68f86SHong Zhang     ierr = PetscSubcommSetType(red->psubcomm,PETSC_SUBCOMM_INTERLACED);CHKERRQ(ierr);
3675f06b7aaSBarry Smith     ierr = PetscLogObjectMemory(pc,sizeof(PetscSubcomm));CHKERRQ(ierr);
3685f06b7aaSBarry Smith 
3695f06b7aaSBarry Smith     /* create a new PC that processors in each subcomm have copy of */
3705f06b7aaSBarry Smith     subcomm = red->psubcomm->comm;
3715f06b7aaSBarry Smith     ierr = KSPCreate(subcomm,&red->ksp);CHKERRQ(ierr);
3725f06b7aaSBarry Smith     ierr = PetscObjectIncrementTabLevel((PetscObject)red->ksp,(PetscObject)pc,1);CHKERRQ(ierr);
3735f06b7aaSBarry Smith     ierr = PetscLogObjectParent(pc,red->ksp);CHKERRQ(ierr);
3745f06b7aaSBarry Smith     ierr = KSPSetType(red->ksp,KSPPREONLY);CHKERRQ(ierr);
3755f06b7aaSBarry Smith     ierr = KSPGetPC(red->ksp,&red->pc);CHKERRQ(ierr);
3765f06b7aaSBarry Smith     ierr = PCSetType(red->pc,PCLU);CHKERRQ(ierr);
3775f06b7aaSBarry Smith 
3785f06b7aaSBarry Smith     ierr = PCGetOptionsPrefix(pc,&prefix);CHKERRQ(ierr);
3795f06b7aaSBarry Smith     ierr = KSPSetOptionsPrefix(red->ksp,prefix);CHKERRQ(ierr);
3805f06b7aaSBarry Smith     ierr = KSPAppendOptionsPrefix(red->ksp,"redundant_");CHKERRQ(ierr);
3815f06b7aaSBarry Smith   }
38283ab6a24SBarry Smith   *innerksp = red->ksp;
3834b9ad928SBarry Smith   PetscFunctionReturn(0);
3844b9ad928SBarry Smith }
3854b9ad928SBarry Smith EXTERN_C_END
3864b9ad928SBarry Smith 
3874b9ad928SBarry Smith #undef __FUNCT__
38883ab6a24SBarry Smith #define __FUNCT__ "PCRedundantGetKSP"
3894b9ad928SBarry Smith /*@
39083ab6a24SBarry Smith    PCRedundantGetKSP - Gets the less parallel KSP created by the redundant PC.
3914b9ad928SBarry Smith 
3924b9ad928SBarry Smith    Not Collective
3934b9ad928SBarry Smith 
3944b9ad928SBarry Smith    Input Parameter:
3954b9ad928SBarry Smith .  pc - the preconditioner context
3964b9ad928SBarry Smith 
3974b9ad928SBarry Smith    Output Parameter:
39883ab6a24SBarry Smith .  innerksp - the KSP on the smaller set of processes
3994b9ad928SBarry Smith 
4004b9ad928SBarry Smith    Level: advanced
4014b9ad928SBarry Smith 
4024b9ad928SBarry Smith .keywords: PC, redundant solve
4034b9ad928SBarry Smith @*/
40483ab6a24SBarry Smith PetscErrorCode  PCRedundantGetKSP(PC pc,KSP *innerksp)
4054b9ad928SBarry Smith {
4064ac538c5SBarry Smith   PetscErrorCode ierr;
4074b9ad928SBarry Smith 
4084b9ad928SBarry Smith   PetscFunctionBegin;
4090700a824SBarry Smith   PetscValidHeaderSpecific(pc,PC_CLASSID,1);
41083ab6a24SBarry Smith   PetscValidPointer(innerksp,2);
41183ab6a24SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantGetKSP_C",(PC,KSP*),(pc,innerksp));CHKERRQ(ierr);
4124b9ad928SBarry Smith   PetscFunctionReturn(0);
4134b9ad928SBarry Smith }
4144b9ad928SBarry Smith 
4154b9ad928SBarry Smith EXTERN_C_BEGIN
4164b9ad928SBarry Smith #undef __FUNCT__
4174b9ad928SBarry Smith #define __FUNCT__ "PCRedundantGetOperators_Redundant"
4187087cfbeSBarry Smith PetscErrorCode  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 @*/
4477087cfbeSBarry Smith PetscErrorCode  PCRedundantGetOperators(PC pc,Mat *mat,Mat *pmat)
4484b9ad928SBarry Smith {
4494ac538c5SBarry Smith   PetscErrorCode ierr;
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);
4554ac538c5SBarry Smith   ierr = PetscTryMethod(pc,"PCRedundantGetOperators_C",(PC,Mat*,Mat*),(pc,mat,pmat));CHKERRQ(ierr);
4564b9ad928SBarry Smith   PetscFunctionReturn(0);
4574b9ad928SBarry Smith }
4584b9ad928SBarry Smith 
4594b9ad928SBarry Smith /* -------------------------------------------------------------------------------------*/
46037a17b4dSBarry Smith /*MC
46183ab6a24SBarry Smith      PCREDUNDANT - Runs a KSP solver with preconditioner for the entire problem on subgroups of processors
46237a17b4dSBarry Smith 
46383ab6a24SBarry Smith      Options for the redundant preconditioners can be set with -redundant_pc_xxx for the redundant KSP with -redundant_ksp_xxx
46437a17b4dSBarry Smith 
46509391456SBarry Smith   Options Database:
4669b21d695SBarry Smith .  -pc_redundant_number <n> - number of redundant solves, for example if you are using 64 MPI processes and
4679b21d695SBarry Smith                               use an n of 4 there will be 4 parallel solves each on 16 = 64/4 processes.
46809391456SBarry Smith 
46937a17b4dSBarry Smith    Level: intermediate
47037a17b4dSBarry Smith 
47183ab6a24SBarry Smith    Notes: The default KSP is preonly and the default PC is LU.
47283ab6a24SBarry Smith 
47383ab6a24SBarry Smith    Developer Notes: Note that PCSetInitialGuessNonzero()  is not used by this class but likely should be.
4749cfaa89bSBarry Smith 
47537a17b4dSBarry Smith .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PCRedundantSetScatter(),
47683ab6a24SBarry Smith            PCRedundantGetKSP(), PCRedundantGetOperators(), PCRedundantSetNumber()
47737a17b4dSBarry Smith M*/
47837a17b4dSBarry Smith 
4794b9ad928SBarry Smith EXTERN_C_BEGIN
4804b9ad928SBarry Smith #undef __FUNCT__
4814b9ad928SBarry Smith #define __FUNCT__ "PCCreate_Redundant"
4827087cfbeSBarry Smith PetscErrorCode  PCCreate_Redundant(PC pc)
4834b9ad928SBarry Smith {
484dfbe8321SBarry Smith   PetscErrorCode ierr;
4854b9ad928SBarry Smith   PC_Redundant   *red;
48669db28dcSHong Zhang   PetscMPIInt    size;
4873f457be1SHong Zhang 
4884b9ad928SBarry Smith   PetscFunctionBegin;
48938f2d2fdSLisandro Dalcin   ierr = PetscNewLog(pc,PC_Redundant,&red);CHKERRQ(ierr);
4907adad957SLisandro Dalcin   ierr = MPI_Comm_size(((PetscObject)pc)->comm,&size);CHKERRQ(ierr);
49169db28dcSHong Zhang   red->nsubcomm       = size;
4924b9ad928SBarry Smith   red->useparallelmat = PETSC_TRUE;
4931fbd8f88SHong Zhang   pc->data            = (void*)red;
4944b9ad928SBarry Smith 
4954b9ad928SBarry Smith   pc->ops->apply           = PCApply_Redundant;
4964b9ad928SBarry Smith   pc->ops->applytranspose  = 0;
4974b9ad928SBarry Smith   pc->ops->setup           = PCSetUp_Redundant;
4984b9ad928SBarry Smith   pc->ops->destroy         = PCDestroy_Redundant;
4991ea5a559SBarry Smith   pc->ops->reset           = PCReset_Redundant;
5004b9ad928SBarry Smith   pc->ops->setfromoptions  = PCSetFromOptions_Redundant;
5014b9ad928SBarry Smith   pc->ops->view            = PCView_Redundant;
5024b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantSetScatter_C","PCRedundantSetScatter_Redundant",
5034b9ad928SBarry Smith                     PCRedundantSetScatter_Redundant);CHKERRQ(ierr);
50409a6bc64SHong Zhang   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantSetNumber_C","PCRedundantSetNumber_Redundant",
50509a6bc64SHong Zhang                     PCRedundantSetNumber_Redundant);CHKERRQ(ierr);
50683ab6a24SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantGetKSP_C","PCRedundantGetKSP_Redundant",
50783ab6a24SBarry Smith                     PCRedundantGetKSP_Redundant);CHKERRQ(ierr);
5084b9ad928SBarry Smith   ierr = PetscObjectComposeFunctionDynamic((PetscObject)pc,"PCRedundantGetOperators_C","PCRedundantGetOperators_Redundant",
5094b9ad928SBarry Smith                     PCRedundantGetOperators_Redundant);CHKERRQ(ierr);
5104b9ad928SBarry Smith   PetscFunctionReturn(0);
5114b9ad928SBarry Smith }
5124b9ad928SBarry Smith EXTERN_C_END
513