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lammps/src/GPU/pair_colloid_gpu.cpp
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pair_colloid_gpu.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.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Trung Dac Nguyen (ORNL)
------------------------------------------------------------------------- */
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "pair_colloid_gpu.h"
#include "atom.h"
#include "atom_vec.h"
#include "comm.h"
#include "force.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "integrate.h"
#include "memory.h"
#include "error.h"
#include "neigh_request.h"
#include "universe.h"
#include "update.h"
#include "domain.h"
#include <string.h>
#include "gpu_extra.h"
using namespace LAMMPS_NS;
// External functions from cuda library for atom decomposition
int colloid_gpu_init(const int ntypes, double **cutsq, double **host_lj1,
double **host_lj2, double **host_lj3, double **host_lj4,
double **offset, double *special_lj, double **host_a12,
double **host_a1, double **host_a2, double **host_d1,
double **host_d2, double **host_sigma3, double **host_sigma6,
int **host_form, const int nlocal,
const int nall, const int max_nbors, const int maxspecial,
const double cell_size, int &gpu_mode, FILE *screen);
void colloid_gpu_clear();
int ** colloid_gpu_compute_n(const int ago, const int inum,
const int nall, double **host_x, int *host_type,
double *sublo, double *subhi, tagint *tag, int **nspecial,
tagint **special, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
int **ilist, int **jnum,
const double cpu_time, bool &success);
void colloid_gpu_compute(const int ago, const int inum, const int nall,
double **host_x, int *host_type, int *ilist, int *numj,
int **firstneigh, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
const double cpu_time, bool &success);
double colloid_gpu_bytes();
/* ---------------------------------------------------------------------- */
PairColloidGPU::PairColloidGPU(LAMMPS *lmp) : PairColloid(lmp), gpu_mode(GPU_FORCE)
{
respa_enable = 0;
reinitflag = 0;
cpu_time = 0.0;
GPU_EXTRA::gpu_ready(lmp->modify, lmp->error);
}
/* ----------------------------------------------------------------------
free all arrays
------------------------------------------------------------------------- */
PairColloidGPU::~PairColloidGPU()
{
colloid_gpu_clear();
}
/* ---------------------------------------------------------------------- */
void PairColloidGPU::compute(int eflag, int vflag)
{
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = vflag_fdotr = 0;
int nall = atom->nlocal + atom->nghost;
int inum, host_start;
bool success = true;
int *ilist, *numneigh, **firstneigh;
if (gpu_mode != GPU_FORCE) {
inum = atom->nlocal;
firstneigh = colloid_gpu_compute_n(neighbor->ago, inum, nall,
atom->x, atom->type, domain->sublo,
domain->subhi, atom->tag, atom->nspecial,
atom->special, eflag, vflag, eflag_atom,
vflag_atom, host_start,
&ilist, &numneigh, cpu_time, success);
} else {
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
colloid_gpu_compute(neighbor->ago, inum, nall, atom->x, atom->type,
ilist, numneigh, firstneigh, eflag, vflag, eflag_atom,
vflag_atom, host_start, cpu_time, success);
}
if (!success)
error->one(FLERR,"Insufficient memory on accelerator");
if (host_start<inum) {
cpu_time = MPI_Wtime();
cpu_compute(host_start, inum, eflag, vflag, ilist, numneigh, firstneigh);
cpu_time = MPI_Wtime() - cpu_time;
}
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairColloidGPU::init_style()
{
if (force->newton_pair)
error->all(FLERR,"Cannot use newton pair with colloid/gpu pair style");
// Repeat cutsq calculation because done after call to init_style
double maxcut = -1.0;
double cut;
for (int i = 1; i <= atom->ntypes; i++) {
for (int j = i; j <= atom->ntypes; j++) {
if (setflag[i][j] != 0 || (setflag[i][i] != 0 && setflag[j][j] != 0)) {
cut = init_one(i,j);
cut *= cut;
if (cut > maxcut)
maxcut = cut;
cutsq[i][j] = cutsq[j][i] = cut;
} else
cutsq[i][j] = cutsq[j][i] = 0.0;
}
}
double cell_size = sqrt(maxcut) + neighbor->skin;
int **_form = NULL;
int n=atom->ntypes;
memory->create(_form,n+1,n+1,"colloid/gpu:_form");
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
if (form[i][j] == SMALL_SMALL) _form[i][j] = 0;
else if (form[i][j] == SMALL_LARGE) _form[i][j] = 1;
else if (form[i][j] == LARGE_LARGE) _form[i][j] = 2;
}
}
int maxspecial=0;
if (atom->molecular)
maxspecial=atom->maxspecial;
int success = colloid_gpu_init(atom->ntypes+1, cutsq, lj1, lj2, lj3, lj4,
offset, force->special_lj, a12, a1, a2,
d1, d2, sigma3, sigma6, _form, atom->nlocal,
atom->nlocal+atom->nghost, 300, maxspecial,
cell_size, gpu_mode, screen);
memory->destroy(_form);
GPU_EXTRA::check_flag(success,error,world);
if (gpu_mode == GPU_FORCE) {
int irequest = neighbor->request(this,instance_me);
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
}
}
/* ---------------------------------------------------------------------- */
double PairColloidGPU::memory_usage()
{
double bytes = Pair::memory_usage();
return bytes + colloid_gpu_bytes();
}
/* ---------------------------------------------------------------------- */
void PairColloidGPU::cpu_compute(int start, int inum, int eflag, int vflag,
int *ilist, int *numneigh, int **firstneigh)
{
int i,j,ii,jj,jnum,itype,jtype;
double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
double r,rsq,r2inv,r6inv,forcelj,factor_lj;
double c1,c2,fR,dUR,dUA;
double K[9],h[4],g[4];
int *jlist;
double **x = atom->x;
double **f = atom->f;
int *type = atom->type;
double *special_lj = force->special_lj;
// loop over neighbors of my atoms
for (ii = start; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
factor_lj = special_lj[sbmask(j)];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
jtype = type[j];
if (rsq >= cutsq[itype][jtype]) continue;
switch (form[itype][jtype]) {
case SMALL_SMALL:
r2inv = 1.0/rsq;
r6inv = r2inv*r2inv*r2inv;
forcelj = r6inv * (lj1[itype][jtype]*r6inv - lj2[itype][jtype]);
fpair = factor_lj*forcelj*r2inv;
if (eflag)
evdwl = r6inv*(r6inv*lj3[itype][jtype]-lj4[itype][jtype]) -
offset[itype][jtype];
break;
case SMALL_LARGE:
c2 = a2[itype][jtype];
K[1] = c2*c2;
K[2] = rsq;
K[0] = K[1] - rsq;
K[4] = rsq*rsq;
K[3] = K[1] - K[2];
K[3] *= K[3]*K[3];
K[6] = K[3]*K[3];
fR = sigma3[itype][jtype]*a12[itype][jtype]*c2*K[1]/K[3];
fpair = 4.0/15.0*fR*factor_lj *
(2.0*(K[1]+K[2]) * (K[1]*(5.0*K[1]+22.0*K[2])+5.0*K[4]) *
sigma6[itype][jtype]/K[6]-5.0) / K[0];
if (eflag)
evdwl = 2.0/9.0*fR *
(1.0-(K[1]*(K[1]*(K[1]/3.0+3.0*K[2])+4.2*K[4])+K[2]*K[4]) *
sigma6[itype][jtype]/K[6]) - offset[itype][jtype];
if (rsq <= K[1])
error->one(FLERR,"Overlapping small/large in pair colloid");
break;
case LARGE_LARGE:
r = sqrt(rsq);
c1 = a1[itype][jtype];
c2 = a2[itype][jtype];
K[0] = c1*c2;
K[1] = c1+c2;
K[2] = c1-c2;
K[3] = K[1]+r;
K[4] = K[1]-r;
K[5] = K[2]+r;
K[6] = K[2]-r;
K[7] = 1.0/(K[3]*K[4]);
K[8] = 1.0/(K[5]*K[6]);
g[0] = pow(K[3],-7.0);
g[1] = pow(K[4],-7.0);
g[2] = pow(K[5],-7.0);
g[3] = pow(K[6],-7.0);
h[0] = ((K[3]+5.0*K[1])*K[3]+30.0*K[0])*g[0];
h[1] = ((K[4]+5.0*K[1])*K[4]+30.0*K[0])*g[1];
h[2] = ((K[5]+5.0*K[2])*K[5]-30.0*K[0])*g[2];
h[3] = ((K[6]+5.0*K[2])*K[6]-30.0*K[0])*g[3];
g[0] *= 42.0*K[0]/K[3]+6.0*K[1]+K[3];
g[1] *= 42.0*K[0]/K[4]+6.0*K[1]+K[4];
g[2] *= -42.0*K[0]/K[5]+6.0*K[2]+K[5];
g[3] *= -42.0*K[0]/K[6]+6.0*K[2]+K[6];
fR = a12[itype][jtype]*sigma6[itype][jtype]/r/37800.0;
evdwl = fR * (h[0]-h[1]-h[2]+h[3]);
dUR = evdwl/r + 5.0*fR*(g[0]+g[1]-g[2]-g[3]);
dUA = -a12[itype][jtype]/3.0*r*((2.0*K[0]*K[7]+1.0)*K[7] +
(2.0*K[0]*K[8]-1.0)*K[8]);
fpair = factor_lj * (dUR+dUA)/r;
if (eflag)
evdwl += a12[itype][jtype]/6.0 *
(2.0*K[0]*(K[7]+K[8])-log(K[8]/K[7])) - offset[itype][jtype];
if (r <= K[1])
error->one(FLERR,"Overlapping large/large in pair colloid");
break;
}
if (eflag) evdwl *= factor_lj;
f[i][0] += delx*fpair;
f[i][1] += dely*fpair;
f[i][2] += delz*fpair;
if (evflag) ev_tally_full(i,evdwl,0.0,fpair,delx,dely,delz);
}
}
}
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