MD-Bench/lammps/cuda/pbc.cu
Rafael Ravedutti 2f13291817 Change function get_num_threads to get_cuda_num_threads
Signed-off-by: Rafael Ravedutti <rafaelravedutti@gmail.com>
2023-11-21 14:40:19 +01:00

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/*
* Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
* All rights reserved. This file is part of MD-Bench.
* Use of this source code is governed by a LGPL-3.0
* license that can be found in the LICENSE file.
*/
#include <stdlib.h>
#include <stdio.h>
//---
extern "C" {
#include <allocate.h>
#include <atom.h>
#include <device.h>
#include <pbc.h>
#include <util.h>
}
extern int NmaxGhost;
extern int *PBCx, *PBCy, *PBCz;
static int c_NmaxGhost = 0;
static int *c_PBCx = NULL, *c_PBCy = NULL, *c_PBCz = NULL;
__global__ void computeAtomsPbcUpdate(DeviceAtom a, int nlocal, MD_FLOAT xprd, MD_FLOAT yprd, MD_FLOAT zprd) {
const int i = blockIdx.x * blockDim.x + threadIdx.x;
DeviceAtom *atom = &a;
if(i >= nlocal) {
return;
}
if (atom_x(i) < 0.0) {
atom_x(i) += xprd;
} else if (atom_x(i) >= xprd) {
atom_x(i) -= xprd;
}
if (atom_y(i) < 0.0) {
atom_y(i) += yprd;
} else if (atom_y(i) >= yprd) {
atom_y(i) -= yprd;
}
if (atom_z(i) < 0.0) {
atom_z(i) += zprd;
} else if (atom_z(i) >= zprd) {
atom_z(i) -= zprd;
}
}
__global__ void computePbcUpdate(DeviceAtom a, int nlocal, int nghost, int* PBCx, int* PBCy, int* PBCz, MD_FLOAT xprd, MD_FLOAT yprd, MD_FLOAT zprd){
const int i = blockIdx.x * blockDim.x + threadIdx.x;
if(i >= nghost) {
return;
}
DeviceAtom* atom = &a;
int *border_map = atom->border_map;
atom_x(nlocal + i) = atom_x(border_map[i]) + PBCx[i] * xprd;
atom_y(nlocal + i) = atom_y(border_map[i]) + PBCy[i] * yprd;
atom_z(nlocal + i) = atom_z(border_map[i]) + PBCz[i] * zprd;
}
/* update coordinates of ghost atoms */
/* uses mapping created in setupPbc */
void updatePbc_cuda(Atom *atom, Parameter *param, bool reneigh) {
const int num_threads_per_block = get_cuda_num_threads();
if(reneigh) {
memcpyToGPU(atom->d_atom.x, atom->x, sizeof(MD_FLOAT) * atom->Nmax * 3);
memcpyToGPU(atom->d_atom.type, atom->type, sizeof(int) * atom->Nmax);
if(c_NmaxGhost < NmaxGhost) {
c_NmaxGhost = NmaxGhost;
c_PBCx = (int *) reallocateGPU(c_PBCx, NmaxGhost * sizeof(int));
c_PBCy = (int *) reallocateGPU(c_PBCy, NmaxGhost * sizeof(int));
c_PBCz = (int *) reallocateGPU(c_PBCz, NmaxGhost * sizeof(int));
atom->d_atom.border_map = (int *) reallocateGPU(atom->d_atom.border_map, NmaxGhost * sizeof(int));
}
memcpyToGPU(c_PBCx, PBCx, NmaxGhost * sizeof(int));
memcpyToGPU(c_PBCy, PBCy, NmaxGhost * sizeof(int));
memcpyToGPU(c_PBCz, PBCz, NmaxGhost * sizeof(int));
memcpyToGPU(atom->d_atom.border_map, atom->border_map, NmaxGhost * sizeof(int));
cuda_assert("updatePbc.reneigh", cudaPeekAtLastError());
cuda_assert("updatePbc.reneigh", cudaDeviceSynchronize());
}
MD_FLOAT xprd = param->xprd;
MD_FLOAT yprd = param->yprd;
MD_FLOAT zprd = param->zprd;
const int num_blocks = ceil((float)atom->Nghost / (float)num_threads_per_block);
computePbcUpdate<<<num_blocks, num_threads_per_block>>>(atom->d_atom, atom->Nlocal, atom->Nghost, c_PBCx, c_PBCy, c_PBCz, xprd, yprd, zprd);
cuda_assert("updatePbc", cudaPeekAtLastError());
cuda_assert("updatePbc", cudaDeviceSynchronize());
}
void updateAtomsPbc_cuda(Atom* atom, Parameter *param) {
const int num_threads_per_block = get_cuda_num_threads();
MD_FLOAT xprd = param->xprd;
MD_FLOAT yprd = param->yprd;
MD_FLOAT zprd = param->zprd;
const int num_blocks = ceil((float)atom->Nlocal / (float)num_threads_per_block);
computeAtomsPbcUpdate<<<num_blocks, num_threads_per_block>>>(atom->d_atom, atom->Nlocal, xprd, yprd, zprd);
cuda_assert("computeAtomsPbcUpdate", cudaPeekAtLastError());
cuda_assert("computeAtomsPbcUpdate", cudaDeviceSynchronize());
memcpyFromGPU(atom->x, atom->d_atom.x, sizeof(MD_FLOAT) * atom->Nlocal * 3);
}