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2026-07-13 12:40:42 +08:00

292 lines
8.7 KiB
Python

# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import copy
import multiprocessing
# TODO: check the hooks of tensor
# TODO: check serializing named tensor
# TODO: check influence on autograd
import sys
import threading
from collections import OrderedDict
from multiprocessing.reduction import ForkingPickler
from multiprocessing.util import register_after_fork
import paddle
def _supported_check():
if sys.platform != "linux":
# warnings.warn("`paddle.multiprocessing` only support linux for now, "
# " import this will not take any effect !")
return False
return True
class _LRUSharedCache(OrderedDict):
def __init__(self):
self.limit = 128
self._after_fork()
register_after_fork(self, _LRUSharedCache._after_fork)
def _after_fork(self):
self.lock = threading.Lock()
def get(self, key):
with self.lock:
try:
value = super().pop(key)
super().__setitem__(key, value)
return value
except KeyError:
return None
def __setitem__(self, key, value):
with self.lock:
try:
super().__delitem__(key)
except KeyError:
if len(self) >= self.limit:
super().popitem(last=False)
super().__setitem__(key, value)
shared_cache = _LRUSharedCache()
def _cuda_from_cache(key):
lodtensor = shared_cache.get(key)
if lodtensor is None:
return None
return lodtensor
def _rebuild_tensor(cls, lodtensor, metadata):
if cls == paddle.base.framework.EagerParamBase:
tensor = paddle.base.framework.EagerParamBase(
lodtensor.shape(), lodtensor._dtype(), **metadata
)
tensor.value().get_tensor()._share_data_with(lodtensor)
else:
size, stop_gradient = metadata
tensor = paddle.base.core.eager.Tensor()
if lodtensor._is_initialized():
tensor.get_tensor()._share_data_with(lodtensor)
else:
tensor = paddle.to_tensor([], dtype=lodtensor._dtype())
tensor.stop_gradient = stop_gradient
return tensor
def _rebuild_vmm_tensor(
cls, blob: bytes, dtype_idx: int, dims: list[int], lod, device: int
):
lodtensor = cls._new_shared_cuda((blob, dtype_idx, dims, lod, device))
return lodtensor
def _reduce_tensor(tensor):
lodtensor = tensor.get_tensor()
if not tensor.stop_gradient and not tensor.is_leaf:
raise RuntimeError(
"Refusing to serialize non-leaf tensor which not stop_gradient, you can detach it!"
)
# TODO: add serializing name and hooks check
if (
tensor.place.is_cpu_place()
or tensor.place.is_gpu_place()
or tensor.place.is_cuda_pinned_place()
or tensor.place.is_xpu_place()
):
if type(tensor) == paddle.base.framework.EagerParamBase:
metadata = copy.deepcopy(tensor.__dict__)
else:
metadata = (tensor.size, tensor.stop_gradient)
return (_rebuild_tensor, (type(tensor), lodtensor, metadata))
else:
raise ValueError(
f"Only support tensors of CPU/CUDA/CUDAPinned Place, Not support {tensor.place} for now!"
)
def _rebuild_lodtensor_filename(
cls,
ipc_name,
shared_fd,
size,
type_idx,
dims,
lod,
dataloader_use_file_descriptor,
):
lodtensor = cls._new_shared_filename(
(
ipc_name,
shared_fd,
size,
type_idx,
dims,
lod,
dataloader_use_file_descriptor,
)
)
lodtensor._shared_decref()
return lodtensor
def _rebuild_lodtensor_filedescriptor(
cls,
ipc_name,
shared_fd,
size,
type_idx,
dims,
lod,
dataloader_use_file_descriptor,
):
shared_fd = shared_fd.detach()
lodtensor = cls._new_shared_filename(
(
ipc_name,
shared_fd,
size,
type_idx,
dims,
lod,
dataloader_use_file_descriptor,
)
)
lodtensor._shared_decref()
return lodtensor
def _rebuild_cuda_tensor(
cls, handle, offset_bytes, size, type_idx, dims, lod, device_idx
):
cache_tensor = _cuda_from_cache((handle, offset_bytes))
if cache_tensor is None:
lodtensor = cls._new_shared_cuda(
(handle, offset_bytes, size, type_idx, dims, lod, device_idx)
)
# We only cache cuda shared tensor here.
# The opening cost of cudaIpcMemoryHandle is very high.
# Since we cache the received tensor directly,
# The sender may reallocate the tensor space,
# you should manually maintain the lifecycle of ipc tensor
shared_cache[(handle, offset_bytes)] = lodtensor
else:
lodtensor = paddle.base.core.DenseTensor()
lodtensor._share_buffer_with(
cache_tensor, (size, type_idx, dims, lod, device_idx)
)
return lodtensor
def _rebuild_xpu_tensor(
cls, handle, offset_bytes, size, type_idx, dims, lod, device_idx
):
cache_tensor = _cuda_from_cache((handle, offset_bytes))
if cache_tensor is None:
lodtensor = cls._new_shared_xpu(
(handle, offset_bytes, size, type_idx, dims, lod, device_idx)
)
# We only cache cuda shared tensor here.
# The opening cost of cudaIpcMemoryHandle is very high.
# Since we cache the received tensor directly,
# The sender may reallocate the tensor space,
# you should manually maintain the lifecycle of ipc tensor
shared_cache[(handle, offset_bytes)] = lodtensor
else:
lodtensor = paddle.base.core.DenseTensor()
lodtensor._share_buffer_with(
cache_tensor, (size, type_idx, dims, lod, device_idx)
)
return lodtensor
def _rebuild_lodtensor_empty(cls):
# TODO: check if tensor initialized
# TODO: handle the dtype of empty tensor
return cls()
def _reduce_lodtensor(lodtensor):
if (
lodtensor._place().is_cpu_place()
or lodtensor._place().is_cuda_pinned_place()
):
for dim in lodtensor.shape():
if dim == 0:
# Empty tensors have nothing be mapped.
return (_rebuild_lodtensor_empty, (type(lodtensor),))
dataloader_use_file_descriptor = paddle.base.core.globals()[
"FLAGS_dataloader_use_file_descriptor"
]
# Default use share filename strategy
metadata = lodtensor._share_filename(
dataloader_use_file_descriptor
) # ipc_name, fd, size, type_idx, dims, lod
if dataloader_use_file_descriptor:
metalist = list(metadata)
metalist[1] = multiprocessing.reduction.DupFd(metalist[1])
metadata = tuple(metalist)
rebuild = _rebuild_lodtensor_filedescriptor
else:
rebuild = _rebuild_lodtensor_filename
lodtensor._shared_incref()
# TODO, maintain reference for lodtensor
elif lodtensor._place().is_gpu_place():
prev_id = paddle.base.core.get_cuda_current_device_id()
cur_id = lodtensor._place().gpu_device_id()
if prev_id != cur_id:
paddle.base.core.set_cuda_current_device_id(cur_id)
try:
metadata = lodtensor._share_cuda()
if len(metadata) == 5:
rebuild = _rebuild_vmm_tensor
else:
rebuild = _rebuild_cuda_tensor
finally:
if prev_id != cur_id:
paddle.base.core.set_cuda_current_device_id(prev_id)
elif lodtensor._place().is_xpu_place():
metadata = lodtensor._share_xpu()
rebuild = _rebuild_xpu_tensor
else:
raise RuntimeError(
"We only support pass cpu/gpu/xpu lodtensor for now!"
)
return (rebuild, (type(lodtensor), *metadata))
def init_reductions() -> None:
if not _supported_check():
return
ForkingPickler.register(paddle.Tensor, _reduce_tensor)
ForkingPickler.register(paddle.base.core.eager.Tensor, _reduce_tensor)
ForkingPickler.register(
paddle.base.framework.EagerParamBase, _reduce_tensor
)
ForkingPickler.register(paddle.base.core.DenseTensor, _reduce_lodtensor)