xref: /phasta/phSolver/compressible/solgmrpetsc.c (revision 178603657237c122e977041f94e6448e6c2fef12)

#ifdef HAVE_PETSC
#include <stdio.h>

#include "petscsys.h"
#include "petscvec.h"
#include "petscmat.h"
#include "petscpc.h"
#include "petscksp.h"

#include "assert.h"
#include "common_c.h"

#include <FCMangle.h>
#define SolGMRp FortranCInterface_GLOBAL_(solgmrp,SOLGMRP)
#define SolGMRpSclr FortranCInterface_GLOBAL_(solgmrpsclr,SOLGMRPSCLR)
#define ElmGMRPETSc FortranCInterface_GLOBAL_(elmgmrpetsc, ELMGMRPETSC)
#define ElmGMRPETScSclr FortranCInterface_GLOBAL_(elmgmrpetscsclr, ELMGMRPETSCSCLR)
#define rstat FortranCInterface_GLOBAL_(rstat, RSTAT)
#define rstatSclr FortranCInterface_GLOBAL_(rstatsclr, RSTATSCLR)
#define min(a,b) (((a) < (b)) ? (a) : (b))
#define max(a,b) (((a) > (b)) ? (a) : (b))
#define get_time FortranCInterface_GLOBAL_(get_time,GET_TIME)
#define get_max_time_diff FortranCInterface_GLOBAL_(get_max_time_diff,GET_MAX_TIME_DIFF)

typedef long long int gcorp_t;

void get_time(uint64_t* rv, uint64_t* cycle);
void get_max_time_diff(uint64_t* first, uint64_t* last, uint64_t* c_first, uint64_t* c_last, char* lbl);

//#include "auxmpi.h"
//      static PetscOffset poff;

      static Mat lhsP;
      static PC pc;
      static KSP ksp;
      static Vec DyP, resP, DyPLocal, resPGlobal;
      static PetscErrorCode ierr;
      static PetscInt PetscOne, PetscRow, PetscCol, LocalRow, LocalCol;
      static IS LocalIndexSet, GlobalIndexSet;
      static ISLocalToGlobalMapping VectorMapping;
      static ISLocalToGlobalMapping GblVectorMapping;
      static  VecScatter scatter7;
      static int firstpetsccall = 1;

      static Mat lhsPs;
      static PC pcs;
      static KSP ksps;
      static Vec DyPs, resPs, DyPLocals, resPGlobals;
      static IS LocalIndexSets, GlobalIndexSets;
      static ISLocalToGlobalMapping VectorMappings;
      static ISLocalToGlobalMapping GblVectorMappings;
      static VecScatter scatter7s;
      static int firstpetsccalls = 1;

void     SolGMRp(double* y,         double* ac,        double* yold,
     	double* x,         int* iBC,       double* BC,
     	int* col,       int* row,       double* lhsk,
     	double* res,       double* BDiag,
     	int* iper,
     	int* ilwork,    double* shp,       double* shgl,      double* shpb,
     	double* shglb,     double* Dy,        double* rerr, long long int* fncorp)
{
//
// ----------------------------------------------------------------------
//
//  This is the preconditioned GMRES driver routine.
//
// input:
//  y      (nshg,ndof)           : Y-variables at n+alpha_v
//  ac     (nshg,ndof)           : Primvar. accel. variable n+alpha_m
//  yold   (nshg,ndof)           : Y-variables at beginning of step
//  acold  (nshg,ndof)           : Primvar. accel. variable at begng step
//  x      (numnp,nsd)            : node coordinates
//  iBC    (nshg)                : BC codes
//  BC     (nshg,ndofBC)         : BC constraint parameters
//  shp(b) (nen,maxsh,melCat)     : element shape functions (boundary)
//  shgl(b)(nsd,nen,maxsh,melCat) : local gradients of shape functions
//
// output:
//  res    (nshg,nflow)           : preconditioned residual
//  BDiag  (nshg,nflow,nflow)      : block-diagonal preconditioner
//
//
// Zdenek Johan,  Winter 1991.  (Fortran 90)
// ----------------------------------------------------------------------
//


// Get variables from common_c.h
      int nshg, nflow, nsd, iownnodes;
      nshg  = conpar.nshg;
      nflow = conpar.nflow;
      nsd = NSD;
      iownnodes = conpar.iownnodes;

      gcorp_t nshgt;
      gcorp_t mbeg;
      gcorp_t mend;
      nshgt = (gcorp_t) newdim.nshgt; //Fix nshgt in common_c.h
      mbeg = (gcorp_t) newdim.minowned;
      mend = (gcorp_t) newdim.maxowned;


      int node, element, var, eqn;
      double valtoinsert;
      int nenl, iel, lelCat, lcsyst, iorder, nshl;
      int mattyp, ndofl, nsymdl, npro, ngauss, nppro;
      double DyFlat[nshg*nflow];
      double DyFlatPhasta[nshg*nflow];
      double rmes[nshg*nflow];
// DEBUG
      int i,j,k,l,m;
      //int indexsetary[nflow*nshg];
      //int gblindexsetary[nflow*nshg];
      PetscInt indexsetary[nflow*nshg];
      PetscInt gblindexsetary[nflow*nshg];
      PetscInt nodetoinsert;

      // FIXME: PetscScalar
      double  real_rtol, real_abstol, real_dtol;
// /DEBUG
      //double parray[1]; // Should be a PetscScalar
      double *parray; // Should be a PetscScalar
      PetscInt petsc_bs, petsc_m, petsc_M,petsc_PA;
      PetscInt petsc_n;
      PetscOne = 1;
      uint64_t duration[4];

//      printf("%g %g %g \n", *rerr, *(rerr+1) , *(rerr+2));

       if(firstpetsccall == 1) {
/*         call get_time(duration(1),duration(2));
         call system('sleep 10');
         call get_time(duration(3),duration(4));
         call get_max_time_diff(duration(1), duration(3),
                              duration(2), duration(4),
                              "TenSecondSleep " // char(0))
         if(myrank .eq. 0) {
           !write(*,"(A, E10.3)") "TenSecondSleep ", elapsed
         }
*/
       }
//
//
// .... *******************>> Element Data Formation <<******************
//
//
// .... set the parameters for flux and surface tension calculations
//
//
      genpar.idflx = 0 ;
      if(genpar.idiff >= 1)  genpar.idflx= genpar.idflx + (nflow-1) * nsd;
      if (genpar.isurf == 1) genpar.idflx=genpar.idflx + nsd;



      PetscInt* idiagnz= (PetscInt*) malloc(sizeof(PetscInt)*iownnodes);
      PetscInt* iodiagnz= (PetscInt*) malloc(sizeof(PetscInt)*iownnodes);
      gcorp_t glbNZ;

      if(firstpetsccall == 1) {
        for(i=0;i<iownnodes;i++) {
             idiagnz[i]=0;
             iodiagnz[i]=0;
        }
        i=0;
        for(k=0;k<nshg;k++) {
          if((fncorp[k] < mbeg) || (fncorp[k] >mend)){
// this node is not owned by this rank so we skip
          } else {
           for(j=col[i]-1;j<col[i+1]-1;j++) {
             glbNZ=fncorp[row[j]];
             if((glbNZ < mbeg) || (glbNZ > mend)) {
                iodiagnz[i]++;
             } else {
                idiagnz[i]++;
             }
           }
           i++;
          }
        }
        gcorp_t mind=1000;
        gcorp_t mino=1000;
        gcorp_t maxd=0;
        gcorp_t maxo=0;
        for(i=0;i<iownnodes;i++) {
           mind=min(mind,idiagnz[i]);
           mino=min(mino,iodiagnz[i]);
           maxd=max(maxd,idiagnz[i]);
           maxo=max(maxo,iodiagnz[i]);
//           iodiagnz[i]=max(iodiagnz[i],10);
//           idiagnz[i]=max(idiagnz[i],10);
//           iodiagnz[i]=2*iodiagnz[i];   //  estimate a bit higher for off-part interactions
//           idiagnz[i]=2*idiagnz[i];   //  estimate a bit higher for off-part interactions
        }
// the above was pretty good but below is faster and not too much more memory...of course once you do this
// could just use the constant fill parameters in create but keep it alive for potential later optimization

        for(i=0;i<iownnodes;i++) {
           iodiagnz[i]=1.3*maxd;
           idiagnz[i]=1.3*maxd;
        }



        if(workfc.numpe < 200){
          printf("myrank,i,iownnodes,nshg %d %d %d %d \n",workfc.myrank,i,iownnodes,nshg);
          printf("myrank,mind,maxd,mino,maxo %d %d %d %d %d \n",workfc.myrank,mind,maxd,mino,maxo);
        }
        // Print debug info
        if(nshgt < 200){
        int irank;
        for(irank=0;irank<workfc.numpe;irank++) {
          if(irank == workfc.myrank){
            printf("mbeg,mend,myrank,idiagnz, iodiagnz %d %d %d \n",mbeg,mend,workfc.myrank);
            for(i=0;i<iownnodes;i++) {
              printf("%d %ld %ld \n",workfc.myrank,idiagnz[i],iodiagnz[i]);
            }
          }
         MPI_Barrier(MPI_COMM_WORLD);
        }
        }
       }
       if(firstpetsccall == 1) {

        petsc_bs = (PetscInt) nflow;
        petsc_m  = (PetscInt) nflow* (PetscInt) iownnodes;
        petsc_M  = (PetscInt) nshgt * (PetscInt) nflow;
        petsc_PA  = (PetscInt) 40;
        // TODO: fixe nshgt for 64 bit integer!!!!!

        //ierr = MatCreateBAIJ(PETSC_COMM_WORLD, nflow, nflow*iownnodes,
        //       nflow*iownnodes, nshgt*nflow, nshgt*nflow, 0,

// this has no pre-allocate        ierr = MatCreateBAIJ(PETSC_COMM_WORLD, petsc_bs, petsc_m, petsc_m, petsc_M, petsc_M,
// this has no pre-allocate                             0, NULL, 0, NULL, &lhsP);

// next 2 do pre-allocate

//      MPI_Barrier(MPI_COMM_WORLD);
//      if(workfc.myrank ==0) printf("Before matCreateBAIJ petsc_bs,petsc_m,petsc_M,petsc_PA %ld %ld %ld %ld \n",petsc_bs,petsc_m,petsc_M,petsc_PA);

        ierr = MatCreateBAIJ(PETSC_COMM_WORLD, petsc_bs, petsc_m, petsc_m, petsc_M, petsc_M,
                             0, idiagnz, 0, iodiagnz, &lhsP);

//                              petsc_PA, NULL, petsc_PA, NULL, &lhsP);
//      MPI_Barrier(MPI_COMM_WORLD);
//      if(workfc.myrank ==0) printf("Before matSetOoption 1  \n");
        ierr = MatSetOption(lhsP, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE);

// Next is Jed Brown's improvement to imprint Assembly to make that stage scalable after the first call
        ierr = MatSetOption(lhsP, MAT_SUBSET_OFF_PROC_ENTRIES, PETSC_TRUE);
        ierr = MatSetUp(lhsP);

      PetscInt myMatStart, myMatEnd;
      ierr = MatGetOwnershipRange(lhsP, &myMatStart, &myMatEnd);
      }
//      MPI_Barrier(MPI_COMM_WORLD);
 //     if(workfc.myrank ==0) printf("Before MatZeroEntries  \n");
      if(genpar.lhs ==1) ierr = MatZeroEntries(lhsP);

      get_time(duration, (duration+1));

//      MPI_Barrier(MPI_COMM_WORLD);
 //     if(workfc.myrank ==0) printf("Before elmgmr  \n");
//      for (i=0; i<nshg ; i++) {
//            assert(fncorp[i]>0);
//      }

      ElmGMRPETSc(y,             ac,            x,
                  shp,           shgl,          iBC,
                  BC,            shpb,
                  shglb,         res,
                  rmes,                   iper,
                  ilwork,        rerr ,         &lhsP);
      get_time((duration+2), (duration+3));
      get_max_time_diff((duration), (duration+2),
                        (duration+1), (duration+3),
                        "ElmGMRPETSc \0");  // char(0))
//       printf("after ElmGMRPETSc\n");
       if(firstpetsccall == 1) {
      // Setup IndexSet. For now, we mimic vector insertion procedure
      // Since we always reference by global indexes this doesn't matter
      // except for cache performance)
      // TODO: Better arrangment?
        nodetoinsert = 0;
        k=0;
        if(workfc.numpe > 1) {
          for (i=0; i<nshg ; i++) {
            nodetoinsert = fncorp[i]-1;
//            if(nodetoinsert<0) printf("nodetoinsert <0! myrank: %d, value: %ld\n", workfc.myrank, nodetoinsert);
//            assert(fncorp[i]>=0);
            for (j=1; j<=nflow; j++) {
              indexsetary[k] = nodetoinsert*nflow+(j-1);
              assert(indexsetary[k]>=0);
//              assert(fncorp[i]>=0);
              k = k+1;
            }
          }
        }
        else {
          for (i=0; i<nshg ; i++) {
            nodetoinsert = i;
            for (j=1; j<=nflow; j++) {
              indexsetary[k] = nodetoinsert*nflow+(j-1);
              k = k+1;
            }
          }
        }

        for (i=0; i<nshg*nflow; i++) {
          gblindexsetary[i] = i ; //TODO: better option for performance?
        }
//  Create Vector Index Maps
        petsc_n  = (PetscInt) nshg * (PetscInt) nflow;
        //ierr = ISCreateGeneral(PETSC_COMM_SELF, nshg*nflow, indexsetary,
     	//       PETSC_COPY_VALUES, &LocalIndexSet);
        ierr = ISCreateGeneral(PETSC_COMM_SELF, petsc_n, indexsetary,
     	       PETSC_COPY_VALUES, &LocalIndexSet);
//        printf("after 1st ISCreateGeneral %d\n", ierr);
        //ierr = ISCreateGeneral(PETSC_COMM_SELF, nshg*nflow, gblindexsetary,
        //       PETSC_COPY_VALUES, &GlobalIndexSet);
        ierr = ISCreateGeneral(PETSC_COMM_SELF, petsc_n, gblindexsetary,
               PETSC_COPY_VALUES, &GlobalIndexSet);
//        printf("after 2nd ISCreateGeneral %d\n", ierr);
        ierr = ISLocalToGlobalMappingCreateIS(LocalIndexSet,&VectorMapping);
//        printf("after 1st ISLocalToGlobalMappingCreateIS %d\n",ierr);
        ierr =  ISLocalToGlobalMappingCreateIS(GlobalIndexSet,&GblVectorMapping);
//        printf("after 2nd ISLocalToGlobalMappingCreateIS %d\n",ierr);
      }
      if(genpar.lhs == 1) {
      get_time((duration), (duration+1));
      ierr = MatAssemblyBegin(lhsP, MAT_FINAL_ASSEMBLY);
      ierr = MatAssemblyEnd(lhsP, MAT_FINAL_ASSEMBLY);
      get_time((duration+2),(duration+3));
      get_max_time_diff((duration), (duration+2),
                        (duration+1), (duration+3),
                        "MatAssembly \0"); // char(0))
      get_time(duration, (duration+1));
      }
      if(firstpetsccall == 1) {
        ierr = MatGetLocalSize(lhsP, &LocalRow, &LocalCol);
//  TODO Should this be LocalRow? LocalCol? or does LocalRow always == LocalCol
        //ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, nshgt*nflow, &resP);
        ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, petsc_M, &resP);
        //ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, nshgt*nflow, &DyP);
        ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, petsc_M, &DyP);
      }
      ierr = VecZeroEntries(resP);
      ierr = VecZeroEntries(DyP);
      if(firstpetsccall == 1) {
        //ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, nshgt*nflow, &resPGlobal);
        ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, petsc_M, &resPGlobal);
        //ierr = VecCreateSeq(PETSC_COMM_SELF, nshg*nflow, &DyPLocal);
        ierr = VecCreateSeq(PETSC_COMM_SELF, petsc_n, &DyPLocal);
      }
        ierr = VecZeroEntries(resPGlobal);
//         call VecZeroEntries(DyPLocal, ierr)

      PetscRow=0;
      k = 0;
      int index;
      for (i=0; i<nshg; i++ ){
        for (j = 1; j<=nflow; j++){
          index = i + (j-1)*nshg;
          valtoinsert = res[index];
          if(workfc.numpe > 1) {
            PetscRow = (fncorp[i]-1)*nflow+(j-1);
          }
          else {
            PetscRow = i*nflow+(j-1);
          }
          assert(fncorp[i]<=nshgt);
          assert(fncorp[i]>0);
          assert(PetscRow>=0);
          assert(PetscRow<=nshgt*nflow);
          ierr =  VecSetValue(resP, PetscRow, valtoinsert, INSERT_VALUES);
        }
      }
//      printf("after VecSetValue loop %d\n",ierr);
      ierr = VecAssemblyBegin(resP);
      ierr = VecAssemblyEnd(resP);
      get_time((duration+2), (duration+3));
      get_max_time_diff((duration), (duration+2),
                        (duration+1), (duration+3),
                        "VectorWorkPre \0"); // char(0))

      get_time((duration),(duration+1));

      if(firstpetsccall == 1) {
        ierr = KSPCreate(PETSC_COMM_WORLD, &ksp);
        ierr = KSPSetOperators(ksp, lhsP, lhsP);
//3.4 ierr = KSPSetOperators(ksp, lhsP, lhsP, SAME_NONZERO_PATTERN);
        ierr = KSPGetPC(ksp, &pc);
        ierr = PCSetType(pc, PCPBJACOBI);
        PetscInt maxits;
        maxits = (PetscInt)  solpar.nGMRES * (PetscInt) solpar.Kspace;
        //ierr = KSPSetTolerances(ksp, timdat.etol, PETSC_DEFAULT, PETSC_DEFAULT, solpar.nGMRES*solpar.Kspace);
        ierr = KSPSetTolerances(ksp, timdat.etol, PETSC_DEFAULT, PETSC_DEFAULT, maxits);
        ierr = KSPSetFromOptions(ksp);
      }
      ierr = KSPSolve(ksp, resP, DyP);
      get_time((duration+2),(duration+3));
      get_max_time_diff((duration), (duration+2),
                        (duration+1), (duration+3),
                        "KSPSolve \0"); // char(0))
     //if(myrank .eq. 0) then
     //!write(*,"(A, E10.3)") "KSPSolve ", elapsed
     //end if
      get_time((duration),(duration+1));
      if(firstpetsccall == 1) {
      ierr = VecScatterCreate(DyP, LocalIndexSet, DyPLocal, GlobalIndexSet, &scatter7);
      }
      ierr = VecScatterBegin(scatter7, DyP, DyPLocal, INSERT_VALUES, SCATTER_FORWARD);
      ierr = VecScatterEnd(scatter7, DyP, DyPLocal, INSERT_VALUES, SCATTER_FORWARD);
      ierr = VecGetArray(DyPLocal, &parray);
      PetscRow = 0;
      for ( node = 0; node< nshg; node++) {
        for (var = 1; var<= nflow; var++) {
          index = node + (var-1)*nshg;
          Dy[index] = parray[PetscRow];
          PetscRow = PetscRow+1;
        }
      }
      ierr = VecRestoreArray(DyPLocal, &parray);

      firstpetsccall = 0;
      // later timer ('Solver  ');

// .... output the statistics
//
      itrpar.iKs=0; // see rstat()
      PetscInt its;
      //ierr = KSPGetIterationNumber(ksp, &itrpar.iKs);
      ierr = KSPGetIterationNumber(ksp, &its);
      itrpar.iKs = (int) its;
      get_time((duration+2),(duration+3));
      get_max_time_diff((duration), (duration+2),
                        (duration+1), (duration+3),
                        "solWork \0"); // char(0))
      itrpar.ntotGM += (int) its;
      rstat (res, ilwork);
//
// .... stop the timer
//
// 3002 continue                  ! no solve just res.
      // later call timer ('Back    ')
//
// .... end
//
}

void     SolGMRpSclr(double* y,         double* ac,
     	double* x,      double* elDw,   int* iBC,       double* BC,
     	int* col,       int* row,
     	int* iper,
     	int* ilwork,    double* shp,       double* shgl,      double* shpb,
     	double* shglb,  double* res,   double* Dy,     long long int* fncorp)
{
//
// ----------------------------------------------------------------------
//
//  This is the preconditioned GMRES driver routine.
//
// input:
//  y      (nshg,ndof)           : Y-variables at n+alpha_v
//  ac     (nshg,ndof)           : Primvar. accel. variable n+alpha_m
//  yold   (nshg,ndof)           : Y-variables at beginning of step
//  acold  (nshg,ndof)           : Primvar. accel. variable at begng step
//  x      (numnp,nsd)            : node coordinates
//  iBC    (nshg)                : BC codes
//  BC     (nshg,ndofBC)         : BC constraint parameters
//  shp(b) (nen,maxsh,melCat)     : element shape functions (boundary)
//  shgl(b)(nsd,nen,maxsh,melCat) : local gradients of shape functions
//
// ----------------------------------------------------------------------
//


// Get variables from common_c.h
      int nshg, nflow, nsd, iownnodes;
      nshg  = conpar.nshg;
      nsd = NSD;
      iownnodes = conpar.iownnodes;

      gcorp_t nshgt;
      gcorp_t mbeg;
      gcorp_t mend;
      nshgt = (gcorp_t) newdim.nshgt; //Fix nshgt in common_c.h
      mbeg = (gcorp_t) newdim.minowned;
      mend = (gcorp_t) newdim.maxowned;


      int node, element, var, eqn;
      double valtoinsert;
      int nenl, iel, lelCat, lcsyst, iorder, nshl;
      int mattyp, ndofl, nsymdl, npro, ngauss, nppro;
      double DyFlats[nshg];
      double DyFlatPhastas[nshg];
      double rmes[nshg];
// DEBUG
      int i,j,k,l,m;
      PetscInt indexsetarys[nshg];
      PetscInt gblindexsetarys[nshg];
      PetscInt nodetoinsert;

      double  real_rtol, real_abstol, real_dtol;
      double *parray;
      PetscInt petsc_bs, petsc_m, petsc_M,petsc_PA;
      PetscInt petsc_n;
      PetscOne = 1;
      uint64_t duration[4];


//
//
// .... *******************>> Element Data Formation <<******************
//
//
// .... set the parameters for flux and surface tension calculations
//
//
      genpar.idflx = 0 ;
      if(genpar.idiff >= 1)  genpar.idflx= genpar.idflx + (nflow-1) * nsd;
      if (genpar.isurf == 1) genpar.idflx=genpar.idflx + nsd;



      PetscInt* idiagnz= (PetscInt*) malloc(sizeof(PetscInt)*iownnodes);
      PetscInt* iodiagnz= (PetscInt*) malloc(sizeof(PetscInt)*iownnodes);
      gcorp_t glbNZ;

      if(firstpetsccalls == 1) {
        for(i=0;i<iownnodes;i++) {
             idiagnz[i]=0;
             iodiagnz[i]=0;
        }
        i=0;
        for(k=0;k<nshg;k++) {
          if((fncorp[k] < mbeg) || (fncorp[k] >mend)){
// this node is not owned by this rank so we skip
          } else {
           for(j=col[i]-1;j<col[i+1]-1;j++) {
             glbNZ=fncorp[row[j]];
             if((glbNZ < mbeg) || (glbNZ > mend)) {
                iodiagnz[i]++;
             } else {
                idiagnz[i]++;
             }
           }
           i++;
          }
        }
        gcorp_t mind=1000;
        gcorp_t mino=1000;
        gcorp_t maxd=0;
        gcorp_t maxo=0;
        for(i=0;i<iownnodes;i++) {
           mind=min(mind,idiagnz[i]);
           mino=min(mino,iodiagnz[i]);
           maxd=max(maxd,idiagnz[i]);
           maxo=max(maxo,iodiagnz[i]);
        }

        for(i=0;i<iownnodes;i++) {
           iodiagnz[i]=1.3*maxd;
           idiagnz[i]=1.3*maxd;
        }



       }
       if(firstpetsccalls == 1) {

        petsc_m  = (PetscInt) iownnodes;
        petsc_M  = (PetscInt) nshgt;
        petsc_PA  = (PetscInt) 40;

        ierr = MatCreateAIJ(PETSC_COMM_WORLD, petsc_m, petsc_m, petsc_M, petsc_M,
                             0, idiagnz, 0, iodiagnz, &lhsPs);

        ierr = MatSetOption(lhsPs, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE);

// Next is Jed Brown's improvement to imprint Assembly to make that stage scalable after the first call
        ierr = MatSetOption(lhsPs, MAT_SUBSET_OFF_PROC_ENTRIES, PETSC_TRUE);
        ierr = MatSetUp(lhsPs);

      PetscInt myMatStart, myMatEnd;
      ierr = MatGetOwnershipRange(lhsP, &myMatStart, &myMatEnd);
      }
//      MPI_Barrier(MPI_COMM_WORLD);
 //     if(workfc.myrank ==0) printf("Before MatZeroEntries  \n");
      if(genpar.lhs == 1) ierr = MatZeroEntries(lhsPs);

      get_time(duration, (duration+1));

//      MPI_Barrier(MPI_COMM_WORLD);
 //     if(workfc.myrank ==0) printf("Before elmgmr  \n");
//      for (i=0; i<nshg ; i++) {
//            assert(fncorp[i]>0);
//      }

      ElmGMRPETScSclr(y,             ac,            x, elDw,
                  shp,           shgl,          iBC,
                  BC,            shpb,
                  shglb,         res,
                  rmes,                   iper,
                  ilwork,        &lhsPs);
       if(firstpetsccalls == 1) {
      // Setup IndexSet. For now, we mimic vector insertion procedure
      // Since we always reference by global indexes this doesn't matter
      // except for cache performance)
      // TODO: Better arrangment?
        nodetoinsert = 0;
        k=0;
        if(workfc.numpe > 1) {
          for (i=0; i<nshg ; i++) {
            nodetoinsert = fncorp[i]-1;
            indexsetarys[k] = nodetoinsert;
            k = k+1;
          }
        }
        else {
          for (i=0; i<nshg ; i++) {
            nodetoinsert = i;
            indexsetarys[k] = nodetoinsert;
            k = k+1;
          }
        }

        for (i=0; i<nshg; i++) {
          gblindexsetarys[i] = i ; //TODO: better option for performance?
        }
//  Create Vector Index Maps
        petsc_n  = (PetscInt) nshg;
        ierr = ISCreateGeneral(PETSC_COMM_SELF, petsc_n, indexsetarys,
     	       PETSC_COPY_VALUES, &LocalIndexSets);
        ierr = ISCreateGeneral(PETSC_COMM_SELF, petsc_n, gblindexsetarys,
               PETSC_COPY_VALUES, &GlobalIndexSets);
        ierr = ISLocalToGlobalMappingCreateIS(LocalIndexSets,&VectorMappings);
        ierr =  ISLocalToGlobalMappingCreateIS(GlobalIndexSets,&GblVectorMappings);
      }
      if(genpar.lhs ==1) {
      ierr = MatAssemblyBegin(lhsPs, MAT_FINAL_ASSEMBLY);
      ierr = MatAssemblyEnd(lhsPs, MAT_FINAL_ASSEMBLY);
      }
      if(firstpetsccalls == 1) {
        ierr = MatGetLocalSize(lhsPs, &LocalRow, &LocalCol);
        ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, petsc_M, &resPs);
        ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, petsc_M, &DyPs);
      }
      ierr = VecZeroEntries(resPs);
      ierr = VecZeroEntries(DyPs);
      if(firstpetsccalls == 1) {
        ierr = VecCreateMPI(PETSC_COMM_WORLD, LocalRow, petsc_M, &resPGlobals);
        ierr = VecCreateSeq(PETSC_COMM_SELF, petsc_n, &DyPLocals);
      }
        ierr = VecZeroEntries(resPGlobals);

      PetscRow=0;
      k = 0;
      int index;
      for (i=0; i<nshg; i++ ){
          valtoinsert = res[i];
          if(workfc.numpe > 1) {
            PetscRow = (fncorp[i]-1);
          }
          else {
            PetscRow = i-1;
          }
          assert(fncorp[i]<=nshgt);
          assert(fncorp[i]>0);
          assert(PetscRow>=0);
          assert(PetscRow<=nshgt);
          ierr =  VecSetValue(resPs, PetscRow, valtoinsert, INSERT_VALUES);
      }
//      printf("after VecSetValue loop %d\n",ierr);
      ierr = VecAssemblyBegin(resPs);
      ierr = VecAssemblyEnd(resPs);

      if(firstpetsccalls == 1) {
        ierr = KSPCreate(PETSC_COMM_WORLD, &ksps);
        ierr = KSPSetOperators(ksps, lhsPs, lhsPs);
//3.4 ierr = KSPSetOperators(ksps, lhsPs, lhsPs, SAME_NONZERO_PATTERN);
        ierr = KSPGetPC(ksps, &pcs);
        ierr = PCSetType(pcs, PCPBJACOBI);
        PetscInt maxits;
        maxits = (PetscInt)  solpar.nGMRES * (PetscInt) solpar.Kspace;
        //ierr = KSPSetTolerances(ksp, timdat.etol, PETSC_DEFAULT, PETSC_DEFAULT, solpar.nGMRES*solpar.Kspace);
        ierr = KSPSetTolerances(ksps, timdat.etol, PETSC_DEFAULT, PETSC_DEFAULT, maxits);
        ierr = KSPSetFromOptions(ksps);
      }
      ierr = KSPSolve(ksps, resPs, DyPs);
      if(firstpetsccalls == 1) {
      ierr = VecScatterCreate(DyPs, LocalIndexSets, DyPLocals, GlobalIndexSets, &scatter7s);
      }
      ierr = VecScatterBegin(scatter7s, DyPs, DyPLocals, INSERT_VALUES, SCATTER_FORWARD);
      ierr = VecScatterEnd(scatter7s, DyPs, DyPLocals, INSERT_VALUES, SCATTER_FORWARD);
      ierr = VecGetArray(DyPLocals, &parray);
      PetscRow = 0;
      for ( node = 0; node< nshg; node++) {
          index = node;
          Dy[index] = parray[PetscRow];
          PetscRow = PetscRow+1;
      }
      ierr = VecRestoreArray(DyPLocals, &parray);

      firstpetsccalls = 0;

// .... output the statistics
//
//      itrpar.iKss=0; // see rstat()
      PetscInt its;
      ierr = KSPGetIterationNumber(ksps, &its);
      itrpar.iKss = (int) its;
      itrpar.ntotGMs += (int) its;
      rstatSclr (res, ilwork);
//
// .... end
//
}
#endif