Hello,
I am trying to implement a large scale LB simulation using palabos (v 1.2). I am having diffculties with parallelIO::load when nproc >= 72. This happens irrespective of whether I use a single atomic block or multiple atomic blocks. Since the code works for nprocs = 60, I have tried writing out the binary file using parallelIO::save with 60 procs and reading it back in with up to 240 procs. This also fails for nprocs>=72. I have used palabos once before (about 1 year ago) and had no problem with scaling the number of processors, so I am a little confused.
The machines I am trying to run simple test cases are Westmere or Nehalem nodes (dual socket hex core or dual socket quad cores with 48 GB RAM per node). I have tried the load operation for 512512512 ints (up to 102410241024 ints)
I am giving a small test code below (for only the load portion). I would appreciate very much if someone could point me in the right direction to resolve the issue.
Thanks,
C.S.N
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#include “palabos3D.h”
#include “palabos3D.hh”
#include
#include
using namespace plb;
typedef double T;
int main(int argc, char **argv)
{
plbInit(&argc, &argv);
const plint nx = atoi(argv[2]); const plint ny = atoi(argv[3]); const plint nz = atoi(argv[4]);
pcout << “Creation of the geomtry.” << endl;
MultiScalarField3D geometry(nx,ny,nz);
pcout << “Reading the geometry file.” << endl;
parallelIO::load(argv[1], geometry);
// parallelIO::save(geometry,“test_out”);
pcout << "Done loading file " << std::endl;
}
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