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lammps/src/imbalance_time.cpp
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imbalance_time.cpp
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/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
#include <mpi.h>
#include "imbalance_time.h"
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "timer.h"
#include "error.h"
using namespace LAMMPS_NS;
#define BIG 1.0e20
/* -------------------------------------------------------------------- */
ImbalanceTime::ImbalanceTime(LAMMPS *lmp) : Imbalance(lmp) {}
/* -------------------------------------------------------------------- */
int ImbalanceTime::options(int narg, char **arg)
{
if (narg < 1) error->all(FLERR,"Illegal balance weight command");
factor = force->numeric(FLERR,arg[0]);
if (factor <= 0.0) error->all(FLERR,"Illegal balance weight command");
return 1;
}
/* ----------------------------------------------------------------------
reset last and timers if necessary
------------------------------------------------------------------------- */
void ImbalanceTime::init(int flag)
{
last = 0.0;
// flag = 1 if called from FixBalance at start of run
// init Timer, so accumulated time not carried over from previous run
// should NOT init Timer if called from Balance, it uses time from last run
if (flag) timer->init();
}
/* -------------------------------------------------------------------- */
void ImbalanceTime::compute(double *weight)
{
if (!timer->has_normal()) return;
// cost = CPU time for relevant timers since last invocation
// localwt = weight assigned to each owned atom
// just return if no time yet tallied
double cost = -last;
cost += timer->get_wall(Timer::PAIR);
cost += timer->get_wall(Timer::NEIGH);
cost += timer->get_wall(Timer::BOND);
cost += timer->get_wall(Timer::KSPACE);
double maxcost;
MPI_Allreduce(&cost,&maxcost,1,MPI_DOUBLE,MPI_MAX,world);
if (maxcost <= 0.0) return;
int nlocal = atom->nlocal;
double localwt = 0.0;
if (nlocal) localwt = cost/nlocal;
if (nlocal && localwt <= 0.0) error->one(FLERR,"Balance weight <= 0.0");
// apply factor if specified != 1.0
// wtlo,wthi = lo/hi values excluding 0.0 due to no atoms on this proc
// lo value does not change
// newhi = new hi value to give hi/lo ratio factor times larger/smaller
// expand/contract all localwt values from lo->hi to lo->newhi
if (factor != 1.0) {
double wtlo,wthi;
if (localwt == 0.0) localwt = BIG;
MPI_Allreduce(&localwt,&wtlo,1,MPI_DOUBLE,MPI_MIN,world);
if (localwt == BIG) localwt = 0.0;
MPI_Allreduce(&localwt,&wthi,1,MPI_DOUBLE,MPI_MAX,world);
if (wtlo == wthi) return;
double newhi = wthi*factor;
localwt = wtlo + ((localwt-wtlo)/(wthi-wtlo)) * (newhi-wtlo);
}
for (int i = 0; i < nlocal; i++) weight[i] *= localwt;
// record time up to this point
last += cost;
}
/* -------------------------------------------------------------------- */
void ImbalanceTime::info(FILE *fp)
{
fprintf(fp," time weight factor: %g\n",factor);
}
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