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37 * \brief Declares CUDA implementation of GPU Halo Exchange.
39 * This header file is needed to include from both the device-side
40 * kernels file, and the host-side management code.
42 * \author Alan Gray <alang@nvidia.com>
44 * \ingroup module_domdec
46 #ifndef GMX_DOMDEC_GPUHALOEXCHANGE_IMPL_H
47 #define GMX_DOMDEC_GPUHALOEXCHANGE_IMPL_H
49 #include "gromacs/domdec/gpuhaloexchange.h"
50 #include "gromacs/gpu_utils/gpueventsynchronizer.cuh"
51 #include "gromacs/gpu_utils/hostallocator.h"
52 #include "gromacs/utility/gmxmpi.h"
57 /*! \brief switch for whether coordinates or force halo is being applied */
58 enum class HaloQuantity
64 /*! \internal \brief Class with interfaces and data for GPU Halo Exchange */
65 class GpuHaloExchange::Impl
69 /*! \brief Creates GPU Halo Exchange object.
71 * \param [inout] dd domdec structure
72 * \param [in] mpi_comm_mysim communicator used for simulation
73 * \param [in] localStream local NB CUDA stream
74 * \param [in] nonLocalStream non-local NB CUDA stream
75 * \param [in] pulse the communication pulse for this instance
77 Impl(gmx_domdec_t* dd, MPI_Comm mpi_comm_mysim, void* localStream, void* nonLocalStream, int pulse);
81 * (Re-) Initialization for GPU halo exchange
82 * \param [in] d_coordinatesBuffer pointer to coordinates buffer in GPU memory
83 * \param [in] d_forcesBuffer pointer to forces buffer in GPU memory
85 void reinitHalo(float3* d_coordinatesBuffer, float3* d_forcesBuffer);
89 * GPU halo exchange of coordinates buffer
90 * \param [in] box Coordinate box (from which shifts will be constructed)
91 * \param [in] coordinatesReadyOnDeviceEvent event recorded when coordinates have been copied to device
93 void communicateHaloCoordinates(const matrix box, GpuEventSynchronizer* coordinatesReadyOnDeviceEvent);
95 /*! \brief GPU halo exchange of force buffer
96 * \param[in] accumulateForces True if forces should accumulate, otherwise they are set
98 void communicateHaloForces(bool accumulateForces);
100 /*! \brief Get the event synchronizer for the forces ready on device.
101 * \returns The event to synchronize the stream that consumes forces on device.
103 GpuEventSynchronizer* getForcesReadyOnDeviceEvent();
106 /*! \brief Data transfer wrapper for GPU halo exchange
107 * \param [inout] d_ptr pointer to coordinates or force buffer in GPU memory
108 * \param [in] haloQuantity switch on whether X or F halo exchange is being performed
109 * \param [in] coordinatesReadyOnDeviceEvent event recorded when coordinates have been copied to device
111 void communicateHaloData(float3* d_ptr,
112 HaloQuantity haloQuantity,
113 GpuEventSynchronizer* coordinatesReadyOnDeviceEvent);
115 /*! \brief Data transfer for GPU halo exchange using CUDA memcopies
116 * \param [inout] sendPtr address to send data from
117 * \param [in] sendSize number of atoms to be sent
118 * \param [in] sendRank rank to send data to
119 * \param [inout] remotePtr remote address to recv data
120 * \param [in] recvRank rank to recv data from
122 void communicateHaloDataWithCudaDirect(void* sendPtr, int sendSize, int sendRank, void* remotePtr, int recvRank);
124 //! Domain decomposition object
125 gmx_domdec_t* dd_ = nullptr;
126 //! map of indices to be sent from this rank
127 gmx::HostVector<int> h_indexMap_;
128 //! device copy of index map
129 int* d_indexMap_ = nullptr;
130 //! number of elements in index map array
131 int indexMapSize_ = -1;
132 //! number of elements allocated in index map array
133 int indexMapSizeAlloc_ = -1;
134 //! device buffer for sending packed data
135 float3* d_sendBuf_ = nullptr;
136 //! number of atoms in sendbuf array
137 int sendBufSize_ = -1;
138 //! number of atoms allocated in sendbuf array
139 int sendBufSizeAlloc_ = -1;
140 //! device buffer for receiving packed data
141 float3* d_recvBuf_ = nullptr;
142 //! maximum size of packed buffer
143 int maxPackedBufferSize_ = 0;
144 //! number of atoms in recvbuf array
145 int recvBufSize_ = -1;
146 //! number of atoms allocated in recvbuf array
147 int recvBufSizeAlloc_ = -1;
148 //! rank to send data to for X
150 //! rank to recv data from for X
152 //! rank to send data to for F
154 //! rank to recv data from for F
156 //! send copy size from this rank for X
158 //! recv copy size to this rank for X
160 //! send copy size from this rank for F
162 //! recv copy size to this rank for F
164 //! number of home atoms - offset of local halo region
165 int numHomeAtoms_ = 0;
166 //! remote GPU coordinates buffer pointer for pushing data
167 void* remoteXPtr_ = nullptr;
168 //! remote GPU force buffer pointer for pushing data
169 void* remoteFPtr_ = nullptr;
170 //! Periodic Boundary Conditions for this rank
171 bool usePBC_ = false;
172 //! force shift buffer on device
173 float3* d_fShift_ = nullptr;
174 //! Event triggered when halo transfer has been launched with direct CUD memory copy
175 GpuEventSynchronizer* haloDataTransferLaunched_ = nullptr;
176 //! MPI communicator used for simulation
177 MPI_Comm mpi_comm_mysim_;
178 //! CUDA stream for local non-bonded calculations
179 cudaStream_t localStream_ = nullptr;
180 //! CUDA stream for non-local non-bonded calculations
181 cudaStream_t nonLocalStream_ = nullptr;
182 //! full coordinates buffer in GPU memory
183 float3* d_x_ = nullptr;
184 //! full forces buffer in GPU memory
185 float3* d_f_ = nullptr;
186 //! An event recorded once the exchanged forces are ready on the GPU
187 GpuEventSynchronizer fReadyOnDevice_;
188 //! The pulse corresponding to this halo exchange instance
190 //! Number of zones. Always 1 for 1-D case.
191 const int nzone_ = 1;