Get memory usage of CUDA GPU, using ctypes and libcudart

py_cudart_memory.py

import ctypes

# Path to location of libcudart
# Change the path to "cudart<x>_<ver>.dll" to use on Windows, where <x>={32|64} and <ver> is the CUDA version. 
_CUDA = "/usr/local/cuda/lib/libcudart.dylib"
cuda = ctypes.cdll.LoadLibrary(_CUDA)

cuda.cudaMemGetInfo.restype = int
cuda.cudaMemGetInfo.argtypes = [ctypes.c_void_p, ctypes.c_void_p]

cuda.cudaGetErrorString.restype = ctypes.c_char_p
cuda.cudaGetErrorString.argtypes = [ctypes.c_int]

def cudaMemGetInfo(mb=False):
    """
    Return (free, total) memory stats for CUDA GPU
    Default units are bytes. If mb==True, return units in MB
    """
    free = ctypes.c_size_t()
    total = ctypes.c_size_t()
    ret = cuda.cudaMemGetInfo(ctypes.byref(free), ctypes.byref(total))

    if ret != 0:
        err = cuda.cudaGetErrorString(status)
        raise RuntimeError("CUDA Error (%d): %s" % (status, err))

    if mb:
        scale = 1024.0**2
        return free.value / scale, total.value / scale
    else:
        return free.value, total.value