9-FF_preconditioning_hpc.edp

// run with: $ mpirun -n 4 FreeFem++-mpi 9-FF_preconditioning_hpc.edp -v 0

load "PETSc"
macro dimension()2// EOM
include "macro_ddm.idp"

// verbosity = 0;
real cpuTime, assemTime, solveTime;

func Pk = P1;
func f=x*y;

bool writeFile = false;
int meshSize = 4000; // a big mesh to evaluate performance, you may even want to increae it

border C(t=0,2*pi){x=2*cos(t);y=sin(t);}
mesh Th = buildmesh(C(meshSize));

int dofBeforePartition; // just for displaying
if (mpirank == 0)
{
  fespace VhDoF(Th, Pk);
  dofBeforePartition = VhDoF.ndof;
}

fespace Vh(Th, Pk);

Mat A;
createMat(Th, A, Pk)

varf weak(u, v) = intN(Th)(dx(u)*dx(v) + dy(u)*dy(v)) + int2d(Th)(f*v) + on(C,u=0);

if (mpirank == 0) {cpuTime = mpiWtime();}

matrix Loc = weak(Vh, Vh);
real[int] b = weak(0, Vh);

A = Loc;
// set(A, sparams="-ksp_view -pc_type lu");
// -pc_type gamg -ksp_type gmres -mat_type mpiaijcusparse
// -pc_type hypre
set(A, sparams="-ksp_view -pc_type hypre");

Vh u;
u[] = A^-1 * b;

if (mpirank == 0) {solveTime = mpiWtime() - cpuTime;}

if (writeFile)
{
	int[int] Order = [1];
	string DataName = "u";
	savevtk("poisson.vtu", Th, u, dataname=DataName, order=Order, append=false);
}

if (mpirank == 0)
{
  cout << "DOF Total: " << dofBeforePartition << endl;
  cout << "DOF: " << Vh.ndof << endl;
  cout << "Solver time: " << solveTime << " s" << endl;
}