ray/rllib/utils/memory.py

73 lines
2.6 KiB
Python

import numpy as np
def aligned_array(size, dtype, align=64):
"""Returns an array of a given size that is 64-byte aligned.
The returned array can be efficiently copied into GPU memory by TensorFlow.
"""
n = size * dtype.itemsize
empty = np.empty(n + (align - 1), dtype=np.uint8)
data_align = empty.ctypes.data % align
offset = 0 if data_align == 0 else (align - data_align)
if n == 0:
# stop np from optimising out empty slice reference
output = empty[offset:offset + 1][0:0].view(dtype)
else:
output = empty[offset:offset + n].view(dtype)
assert len(output) == size, len(output)
assert output.ctypes.data % align == 0, output.ctypes.data
return output
def concat_aligned(items, time_major=None):
"""Concatenate arrays, ensuring the output is 64-byte aligned.
We only align float arrays; other arrays are concatenated as normal.
This should be used instead of np.concatenate() to improve performance
when the output array is likely to be fed into TensorFlow.
Args:
items (List(np.ndarray)): The list of items to concatenate and align.
time_major (bool): Whether the data in items is time-major, in which
case, we will concatenate along axis=1.
Returns:
np.ndarray: The concat'd and aligned array.
"""
if len(items) == 0:
return []
elif len(items) == 1:
# we assume the input is aligned. In any case, it doesn't help
# performance to force align it since that incurs a needless copy.
return items[0]
elif (isinstance(items[0], np.ndarray)
and items[0].dtype in [np.float32, np.float64, np.uint8]):
dtype = items[0].dtype
flat = aligned_array(sum(s.size for s in items), dtype)
if time_major is not None:
if time_major is True:
batch_dim = sum(s.shape[1] for s in items)
new_shape = (
items[0].shape[0],
batch_dim,
) + items[0].shape[2:]
else:
batch_dim = sum(s.shape[0] for s in items)
new_shape = (
batch_dim,
items[0].shape[1],
) + items[0].shape[2:]
else:
batch_dim = sum(s.shape[0] for s in items)
new_shape = (batch_dim, ) + items[0].shape[1:]
output = flat.reshape(new_shape)
assert output.ctypes.data % 64 == 0, output.ctypes.data
np.concatenate(items, out=output, axis=1 if time_major else 0)
return output
else:
return np.concatenate(items, axis=1 if time_major else 0)