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fix_temp_rescale_cuda.cpp
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Sat, Oct 5, 05:20
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text/x-c
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Mon, Oct 7, 05:20 (2 d)
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rLAMMPS lammps
fix_temp_rescale_cuda.cpp
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/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
Original Version:
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
See the README file in the top-level LAMMPS directory.
-----------------------------------------------------------------------
USER-CUDA Package and associated modifications:
https://sourceforge.net/projects/lammpscuda/
Christian Trott, christian.trott@tu-ilmenau.de
Lars Winterfeld, lars.winterfeld@tu-ilmenau.de
Theoretical Physics II, University of Technology Ilmenau, Germany
See the README file in the USER-CUDA directory.
This software is distributed under the GNU General Public License.
------------------------------------------------------------------------- */
#include <cstring>
#include <cstdlib>
#include <cmath>
#include "fix_temp_rescale_cuda.h"
#include "fix_temp_rescale_cuda_cu.h"
#include "atom.h"
#include "force.h"
#include "group.h"
#include "update.h"
#include "domain.h"
#include "region.h"
#include "comm.h"
#include "modify.h"
#include "compute.h"
#include "error.h"
#include "cuda.h"
#include "cuda_modify_flags.h"
using
namespace
LAMMPS_NS
;
enum
{
NOBIAS
,
BIAS
};
/* ---------------------------------------------------------------------- */
FixTempRescaleCuda
::
FixTempRescaleCuda
(
LAMMPS
*
lmp
,
int
narg
,
char
**
arg
)
:
Fix
(
lmp
,
narg
,
arg
)
{
cuda
=
lmp
->
cuda
;
if
(
cuda
==
NULL
)
error
->
all
(
FLERR
,
"You cannot use a /cuda class, without activating 'cuda' acceleration. Provide '-c on' as command-line argument to LAMMPS.."
);
if
(
narg
<
8
)
error
->
all
(
FLERR
,
"Illegal fix temp/rescale/cuda command"
);
nevery
=
atoi
(
arg
[
3
]);
if
(
nevery
<=
0
)
error
->
all
(
FLERR
,
"Illegal fix temp/rescale/cuda command"
);
scalar_flag
=
1
;
global_freq
=
nevery
;
extscalar
=
1
;
t_start
=
atof
(
arg
[
4
]);
t_stop
=
atof
(
arg
[
5
]);
t_window
=
atof
(
arg
[
6
]);
fraction
=
atof
(
arg
[
7
]);
// create a new compute temp
// id = fix-ID + temp, compute group = fix group
int
n
=
strlen
(
id
)
+
6
;
id_temp
=
new
char
[
n
];
strcpy
(
id_temp
,
id
);
strcat
(
id_temp
,
"_temp"
);
char
**
newarg
=
new
char
*
[
6
];
newarg
[
0
]
=
id_temp
;
newarg
[
1
]
=
group
->
names
[
igroup
];
newarg
[
2
]
=
(
char
*
)
"temp/cuda"
;
modify
->
add_compute
(
3
,
newarg
);
delete
[]
newarg
;
tflag
=
1
;
energy
=
0.0
;
}
/* ---------------------------------------------------------------------- */
FixTempRescaleCuda
::~
FixTempRescaleCuda
()
{
// delete temperature if fix created it
if
(
tflag
)
modify
->
delete_compute
(
id_temp
);
delete
[]
id_temp
;
}
/* ---------------------------------------------------------------------- */
int
FixTempRescaleCuda
::
setmask
()
{
int
mask
=
0
;
mask
|=
END_OF_STEP_CUDA
;
mask
|=
THERMO_ENERGY_CUDA
;
return
mask
;
}
/* ---------------------------------------------------------------------- */
void
FixTempRescaleCuda
::
init
()
{
int
icompute
=
modify
->
find_compute
(
id_temp
);
if
(
icompute
<
0
)
error
->
all
(
FLERR
,
"Temperature ID for fix temp/rescale/cuda does not exist"
);
temperature
=
modify
->
compute
[
icompute
];
if
(
not
temperature
->
cudable
)
error
->
warning
(
FLERR
,
"Fix temp/rescale/cuda uses non cudable temperature compute"
);
if
(
temperature
->
tempbias
)
which
=
BIAS
;
else
which
=
NOBIAS
;
}
/* ---------------------------------------------------------------------- */
void
FixTempRescaleCuda
::
end_of_step
()
{
double
t_current
;
if
(
not
temperature
->
cudable
)
{
cuda
->
cu_x
->
download
();
cuda
->
cu_v
->
download
();}
t_current
=
temperature
->
compute_scalar
();
if
(
t_current
==
0.0
)
error
->
all
(
FLERR
,
"Computed temperature for fix temp/rescale/cuda cannot be 0.0"
);
double
delta
=
update
->
ntimestep
-
update
->
beginstep
;
delta
/=
update
->
endstep
-
update
->
beginstep
;
double
t_target
=
t_start
+
delta
*
(
t_stop
-
t_start
);
// rescale velocity of appropriate atoms if outside window
if
(
fabs
(
t_current
-
t_target
)
>
t_window
)
{
t_target
=
t_current
-
fraction
*
(
t_current
-
t_target
);
double
factor
=
sqrt
(
t_target
/
t_current
);
double
efactor
=
0.5
*
force
->
boltz
*
temperature
->
dof
;
double
**
v
=
atom
->
v
;
int
*
mask
=
atom
->
mask
;
int
nlocal
=
atom
->
nlocal
;
if
(
which
==
NOBIAS
)
{
energy
+=
(
t_current
-
t_target
)
*
efactor
;
Cuda_FixTempRescaleCuda_EndOfStep
(
&
cuda
->
shared_data
,
groupbit
,
factor
);
}
else
if
(
which
==
BIAS
)
{
energy
+=
(
t_current
-
t_target
)
*
efactor
;
if
(
not
temperature
->
cudable
)
{
cuda
->
cu_x
->
download
();
cuda
->
cu_v
->
download
();
for
(
int
i
=
0
;
i
<
nlocal
;
i
++
)
{
if
(
mask
[
i
]
&
groupbit
)
{
temperature
->
remove_bias
(
i
,
v
[
i
]);
v
[
i
][
0
]
*=
factor
;
v
[
i
][
1
]
*=
factor
;
v
[
i
][
2
]
*=
factor
;
temperature
->
restore_bias
(
i
,
v
[
i
]);
}
}
cuda
->
cu_v
->
upload
();
}
else
{
temperature
->
remove_bias_all
();
Cuda_FixTempRescaleCuda_EndOfStep
(
&
cuda
->
shared_data
,
groupbit
,
factor
);
temperature
->
restore_bias_all
();
}
}
}
}
/* ---------------------------------------------------------------------- */
int
FixTempRescaleCuda
::
modify_param
(
int
narg
,
char
**
arg
)
{
if
(
strcmp
(
arg
[
0
],
"temp"
)
==
0
)
{
if
(
narg
<
2
)
error
->
all
(
FLERR
,
"Illegal fix_modify command"
);
if
(
tflag
)
{
modify
->
delete_compute
(
id_temp
);
tflag
=
0
;
}
delete
[]
id_temp
;
int
n
=
strlen
(
arg
[
1
])
+
1
;
id_temp
=
new
char
[
n
];
strcpy
(
id_temp
,
arg
[
1
]);
int
icompute
=
modify
->
find_compute
(
id_temp
);
if
(
icompute
<
0
)
error
->
all
(
FLERR
,
"Could not find fix_modify temperature ID"
);
temperature
=
modify
->
compute
[
icompute
];
if
(
temperature
->
tempflag
==
0
)
error
->
all
(
FLERR
,
"Fix_modify temperature ID does not compute temperature"
);
if
(
temperature
->
igroup
!=
igroup
&&
comm
->
me
==
0
)
error
->
warning
(
FLERR
,
"Group for fix_modify temp != fix group"
);
if
(
not
temperature
->
cudable
)
error
->
warning
(
FLERR
,
"Fix temp/rescale/cuda uses non cudable temperature compute"
);
return
2
;
}
return
0
;
}
/* ---------------------------------------------------------------------- */
void
FixTempRescaleCuda
::
reset_target
(
double
t_new
)
{
t_start
=
t_stop
=
t_new
;
}
/* ---------------------------------------------------------------------- */
double
FixTempRescaleCuda
::
compute_scalar
()
{
return
energy
;
}
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