ColossalAI/colossalai/tensor/colo_tensor.py

107 lines
3.7 KiB
Python

from numpy import product
import torch
from typing import Tuple
import numpy
from .op_wrapper import _COLOSSAL_OPS
class ColoTensor(object):
""" Data Structure for Tensor in Colossal-AI
1. It contains a torch.Tensor as an attribute.
2. It supports lazy init the tensor's payload.
3. It can hijack the torch functions which using ColoTensors as args to our customized functions.
4. It supports distributing the tensor's payload to the shards among processes. (TODO)
"""
def __new__(cls, *args, **kwargs):
return super(ColoTensor, cls).__new__(cls)
def __init__(
self,
*size: Tuple[int],
dtype=None,
requires_grad=False,
pin_memory=False,
device=None,
torch_tensor=torch.empty(0),
shard_spec: str = None,
):
self._size = size
self._dtype = dtype
self._requires_grad = requires_grad
self._pin_memory = pin_memory
self._device = device
self._torch_tensor = torch_tensor
self._shard_spec = shard_spec
@property
def shard_spec(self) -> Optional[str]:
return self._shard_spec
@property
def data(self):
return self._torch_tensor.data
@property
def grad(self):
return self._torch_tensor.grad
@property
def size(self):
return self._size
def numel(self):
return product(self._size)
@staticmethod
def init_from_torch_tensor(tensor: torch.Tensor, save_payload=True) -> 'ColoTensor':
colo_t = ColoTensor(*tensor.size(),
dtype=tensor.dtype,
requires_grad=tensor.requires_grad,
pin_memory=tensor.is_pinned(),
device=tensor.device,
torch_tensor=tensor if save_payload else torch.empty(0))
return colo_t
def del_torch_tensor(self, save_shape=False) -> None:
"""
delete the payload of the torch tensor.
Args:
save_shape (bool, optional): if saving the shape of the torch_tensor.
If saving the shape, the size of self._torch_tensor is inconsist with the self._size.
Defaults to False.
"""
if not save_shape:
self._size = (0,)
self._torch_tensor = torch.empty((0,), device=self._device, dtype=self._dtype)
def torch_tensor(self) -> torch.Tensor:
if self._torch_tensor.numel() == 0:
self._torch_tensor = torch.empty(*self._size,
dtype=self._dtype,
pin_memory=self._pin_memory,
requires_grad=self._requires_grad,
device=self._device)
return self._torch_tensor
@classmethod
def __torch_function__(cls, func, types, args=(), kwargs=None):
global _COLOSSAL_OPS
if func in _COLOSSAL_OPS:
for arg in args:
if isinstance(arg, ColoTensor):
return _COLOSSAL_OPS[func](types, args, kwargs, None)
for kwarg in kwargs.values():
if isinstance(kwarg, ColoTensor):
return _COLOSSAL_OPS[func](types, args, kwargs, None)
else:
# If we have not hijact the function, convert the ColoTensors in args and kwargs to torch tensors.
args = [arg.torch_tensor() if isinstance(arg, ColoTensor) else arg for arg in args]
if kwargs is None:
kwargs = {}
kwargs = {k: v.torch_tensor() if isinstance(v, ColoTensor) else v for k, v in kwargs.items()}
return func(*args, **kwargs)