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37 * \brief Declares GPU implementation class for update and constraints.
39 * This header file is needed to include from both the device-side
40 * kernels file, and the host-side management code.
42 * \author Artem Zhmurov <zhmurov@gmail.com>
44 * \ingroup module_mdlib
46 #ifndef GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H
47 #define GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H
51 #include "gromacs/mdlib/leapfrog_gpu.h"
52 #include "gromacs/mdlib/lincs_gpu.h"
53 #include "gromacs/mdlib/settle_gpu.cuh"
54 #include "gromacs/mdlib/update_constrain_gpu.h"
55 #include "gromacs/mdtypes/inputrec.h"
57 class GpuEventSynchronizer;
62 /*! \internal \brief Class with interfaces and data for GPU version of Update-Constraint. */
63 class UpdateConstrainGpu::Impl
67 /*! \brief Create Update-Constrain object.
69 * The constructor is given a non-nullptr \p deviceStream, in which all the update and constrain
70 * routines are executed. \p xUpdatedOnDevice should mark the completion of all kernels that
71 * modify coordinates. The event is maintained outside this class and also passed to all (if
72 * any) consumers of the updated coordinates. The \p xUpdatedOnDevice also can not be a nullptr
73 * because the markEvent(...) method is called unconditionally.
75 * \param[in] ir Input record data: LINCS takes number of iterations and order of
77 * \param[in] mtop Topology of the system: SETTLE gets the masses for O and H atoms
78 * and target O-H and H-H distances from this object.
79 * \param[in] numTempScaleValues Number of temperature scaling groups. Set zero for no temperature coupling.
80 * \param[in] deviceContext GPU device context.
81 * \param[in] deviceStream GPU stream to use.
82 * \param[in] xUpdatedOnDevice The event synchronizer to use to mark that
83 * update is done on the GPU.
84 * \param[in] wcycle The wallclock counter
86 Impl(const t_inputrec& ir,
87 const gmx_mtop_t& mtop,
88 int numTempScaleValues,
89 const DeviceContext& deviceContext,
90 const DeviceStream& deviceStream,
91 GpuEventSynchronizer* xUpdatedOnDevice,
92 gmx_wallcycle* wcycle);
98 * Integrates the equation of motion using Leap-Frog algorithm and applies
99 * LINCS and SETTLE constraints.
100 * If computeVirial is true, constraints virial is written at the provided pointer.
101 * doTempCouple should be true if:
102 * 1. The temperature coupling is enabled.
103 * 2. This is the temperature coupling step.
104 * Parameters virial/lambdas can be nullptr if computeVirial/doTempCouple are false.
106 * \param[in] fReadyOnDevice Event synchronizer indicating that the forces are ready in
108 * \param[in] dt Timestep.
109 * \param[in] updateVelocities If the velocities should be constrained.
110 * \param[in] computeVirial If virial should be updated.
111 * \param[out] virial Place to save virial tensor.
112 * \param[in] doTemperatureScaling If velocities should be scaled for temperature coupling.
113 * \param[in] tcstat Temperature coupling data.
114 * \param[in] doParrinelloRahman If current step is a Parrinello-Rahman pressure coupling step.
115 * \param[in] dtPressureCouple Period between pressure coupling steps.
116 * \param[in] prVelocityScalingMatrix Parrinello-Rahman velocity scaling matrix.
118 void integrate(GpuEventSynchronizer* fReadyOnDevice,
120 bool updateVelocities,
123 bool doTemperatureScaling,
124 gmx::ArrayRef<const t_grp_tcstat> tcstat,
125 bool doParrinelloRahman,
126 float dtPressureCouple,
127 const matrix prVelocityScalingMatrix);
129 /*! \brief Scale coordinates on the GPU for the pressure coupling.
131 * After pressure coupling step, the box size may change. Hence, the coordinates should be
132 * scaled so that all the particles fit in the new box.
134 * \param[in] scalingMatrix Coordinates scaling matrix.
136 void scaleCoordinates(const matrix scalingMatrix);
138 /*! \brief Scale velocities on the GPU for the pressure coupling.
140 * After pressure coupling step, the box size may change. In the C-Rescale algorithm, velocities should be scaled.
142 * \param[in] scalingMatrix Velocities scaling matrix.
144 void scaleVelocities(const matrix scalingMatrix);
146 /*! \brief Set the pointers and update data-structures (e.g. after NB search step).
148 * \param[in,out] d_x Device buffer with coordinates.
149 * \param[in,out] d_v Device buffer with velocities.
150 * \param[in] d_f Device buffer with forces.
151 * \param[in] idef System topology
152 * \param[in] md Atoms data.
154 void set(DeviceBuffer<Float3> d_x,
155 DeviceBuffer<Float3> d_v,
156 const DeviceBuffer<Float3> d_f,
157 const InteractionDefinitions& idef,
158 const t_mdatoms& md);
163 * Converts PBC data from t_pbc into the PbcAiuc format and stores the latter.
165 * \param[in] pbcType The type of the periodic boundary.
166 * \param[in] box The periodic boundary box matrix.
168 void setPbc(PbcType pbcType, const matrix box);
170 /*! \brief Return the synchronizer associated with the event indicated that the coordinates are ready on the device.
172 GpuEventSynchronizer* getCoordinatesReadySync();
175 * Returns whether the maximum number of coupled constraints is supported
176 * by the GPU LINCS code.
178 * \param[in] mtop The molecular topology
180 static bool isNumCoupledConstraintsSupported(const gmx_mtop_t& mtop);
183 //! GPU context object
184 const DeviceContext& deviceContext_;
186 const DeviceStream& deviceStream_;
187 //! GPU kernel launch config
188 KernelLaunchConfig coordinateScalingKernelLaunchConfig_;
190 //! Periodic boundary data
196 //! Local copy of the pointer to the device positions buffer
197 DeviceBuffer<Float3> d_x_;
198 //! Local copy of the pointer to the device velocities buffer
199 DeviceBuffer<Float3> d_v_;
200 //! Local copy of the pointer to the device forces buffer
201 DeviceBuffer<Float3> d_f_;
203 //! Device buffer for intermediate positions (maintained internally)
204 DeviceBuffer<Float3> d_xp_;
205 //! Number of elements in shifted coordinates buffer
207 //! Allocation size for the shifted coordinates buffer
208 int numXpAlloc_ = -1;
211 //! 1/mass for all atoms (GPU)
212 DeviceBuffer<real> d_inverseMasses_;
213 //! Number of elements in reciprocal masses buffer
214 int numInverseMasses_ = -1;
215 //! Allocation size for the reciprocal masses buffer
216 int numInverseMassesAlloc_ = -1;
218 //! Leap-Frog integrator
219 std::unique_ptr<LeapFrogGpu> integrator_;
220 //! LINCS GPU object to use for non-water constraints
221 std::unique_ptr<LincsGpu> lincsGpu_;
222 //! SETTLE GPU object for water constrains
223 std::unique_ptr<SettleGpu> settleGpu_;
225 //! An pointer to the event to indicate when the update of coordinates is complete
226 GpuEventSynchronizer* coordinatesReady_;
227 //! The wallclock counter
228 gmx_wallcycle* wcycle_ = nullptr;
231 /*! \brief Scaling matrix struct.
233 * \todo Should be generalized.
237 ScalingMatrix(const matrix m) :
246 float xx, yy, zz, yx, zx, zy;
251 #endif // GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H