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36 * \brief Define functions for host-side memory handling when using OpenCL devices.
38 * \author Anca Hamuraru <anca@streamcomputing.eu>
45 #include "gromacs/utility/smalloc.h"
47 /*! \brief \brief Allocates nbytes of host memory. Use pfree to free memory allocated with this function.
50 * This function should allocate page-locked memory to help reduce D2H and H2D
51 * transfer times, similar with pmalloc from pmalloc.cu.
53 * \param[in,out] h_ptr Pointer where to store the address of the newly allocated buffer.
54 * \param[in] nbytes Size in bytes of the buffer to be allocated.
56 void pmalloc(void** h_ptr, size_t nbytes)
58 /* Need a temporary type whose size is 1 byte, so that the
59 * implementation of snew_aligned can cope without issuing
61 char** temporary = reinterpret_cast<char**>(h_ptr);
63 /* 16-byte alignment is required by the neighbour-searching code,
64 * because it uses four-wide SIMD for bounding-box calculation.
65 * However, when we organize using page-locked memory for
66 * device-host transfers, it will probably need to be aligned to a
67 * 4kb page, like CUDA does. */
68 snew_aligned(*temporary, nbytes, 16);
71 /*! \brief Frees memory allocated with pmalloc.
73 * \param[in] h_ptr Buffer allocated with pmalloc that needs to be freed.
75 void pfree(void* h_ptr)