68 lines
2.6 KiB
Python
68 lines
2.6 KiB
Python
# Copyright (c) Microsoft Corporation.
|
|
# SPDX-License-Identifier: Apache-2.0
|
|
|
|
# DeepSpeed Team
|
|
|
|
import os
|
|
import torch
|
|
from .constants import (MODEL_FILE_PREFIX, MODEL_FILE_SUFFIX, OPTIM_FILE_SUFFIX, ZERO_FILE_PREFIX)
|
|
|
|
|
|
def get_model_ckpt_name_for_rank(base_folder, mp_rank_str):
|
|
ckpt_name = os.path.join(
|
|
base_folder,
|
|
MODEL_FILE_PREFIX + mp_rank_str + MODEL_FILE_SUFFIX,
|
|
)
|
|
return ckpt_name
|
|
|
|
|
|
def get_zero_ckpt_name_for_rank(base_folder, dp_rank, mp_rank):
|
|
zero_prefix = f'{ZERO_FILE_PREFIX}{dp_rank}'
|
|
mp_rank_string = f'_{MODEL_FILE_PREFIX}{mp_rank:02d}'
|
|
zero_ckpt_name = os.path.join(
|
|
base_folder,
|
|
zero_prefix + mp_rank_string + OPTIM_FILE_SUFFIX,
|
|
)
|
|
return zero_ckpt_name
|
|
|
|
|
|
def get_layer_ckpt_name_for_rank(base_folder, layer_id, tp_rank):
|
|
ckpt_file = f'{layer_id}-model_{tp_rank:02d}{MODEL_FILE_SUFFIX}'
|
|
ckpt_path = os.path.join(base_folder, ckpt_file)
|
|
return ckpt_path
|
|
|
|
|
|
# We pass cloned tensors to torch.save() to avoid checkpoint bloat that occurs when torch.save()
|
|
# saves the underlying storage rather than the slice of the storage corresponding to individual tensors.
|
|
# This is a problem in DeepSpeed because we often allocate tensors using slices of large flattened buffers.
|
|
# Tensor cloning helps to avoid this problem because the storage of cloned tensors are closer to the true size.
|
|
# It is expected that the garbage collector will reclaim the cloned tensor storage to avoid memory bloat.
|
|
# See https://pytorch.org/docs/stable/notes/serialization.html#preserve-storage-sharing
|
|
def clone_tensors_for_torch_save(item, device=torch.device('cpu')):
|
|
"""
|
|
Returns a copy of ``item`` with all enclosed tensors replaced by clones on a specified device.
|
|
Works on individual tensors, and tensors contained/nested in lists, tuples, and dicts.
|
|
|
|
Parameters:
|
|
- ``item``: tensor to clone or (possibly nested) container of tensors to clone.
|
|
- ``device``: target device (defaults to 'cpu')
|
|
|
|
Returns:
|
|
- copy of ``item`` with cloned tensors on target device
|
|
"""
|
|
if torch.is_tensor(item):
|
|
if type(device) is str:
|
|
device = torch.device(device)
|
|
if device == item.device:
|
|
return item.detach().clone()
|
|
else:
|
|
return item.detach().to(device)
|
|
elif isinstance(item, list):
|
|
return [clone_tensors_for_torch_save(v, device) for v in item]
|
|
elif isinstance(item, tuple):
|
|
return tuple([clone_tensors_for_torch_save(v, device) for v in item])
|
|
elif isinstance(item, dict):
|
|
return type(item)({k: clone_tensors_for_torch_save(v, device) for k, v in item.items()})
|
|
else:
|
|
return item
|