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

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Python

# Copyright (c) 2023 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.
from __future__ import annotations
import multiprocessing
import os
import time
from collections import defaultdict
from dataclasses import replace
from typing import TYPE_CHECKING
import paddle
from paddle.distributed.communication.group import is_initialized
from paddle.distributed.fleet.utils.log_util import logger
from .metadata import LocalTensorIndex, Metadata
from .sharded_weight import (
ShardedWeight,
)
from .utils import (
check_unique_id,
extract_tensor_metadata,
flatten_state_dict,
get_max_id,
merge_state_dict_metadata,
write_to_file_if_empty,
)
if TYPE_CHECKING:
from paddle import Tensor
from paddle.distributed.collective import Group
async_save_queue = []
def check_exitcode(task):
exitcode = task.exitcode
if exitcode != 0:
logger.error(
f"Error: save ckpt process failed with exitcode {exitcode}!!!"
)
def clear_async_save_task_queue():
"""
wait until all async save task to be done.
"""
while len(async_save_queue) > 0:
task = async_save_queue.pop()
if task and task.is_alive():
task.join(timeout=60)
if task.is_alive():
logger.error("Error: save ckpt process timeout!!!")
async_save_queue.append(task)
else:
check_exitcode(task)
else:
check_exitcode(task)
def copy_dict_to_cpu(nested_dict):
"""
Copy the paddle.Tensor objects in the nested dictionary to the CPU and return a new dict.
"""
new_dict = {}
for key, value in nested_dict.items():
if isinstance(value, paddle.Tensor):
new_dict[key] = value.cpu()
paddle.device.synchronize()
elif isinstance(value, dict):
new_dict[key] = copy_dict_to_cpu(value)
else:
new_dict[key] = value
return new_dict
def dedup_key_in_dict(global_storage_metadata):
out = {}
for storage_metadata in global_storage_metadata:
for key, val in storage_metadata.items():
if key in out:
continue
out[key] = val
return out
def balanced_dedup_key_in_dict(global_storage_metadata, save_replicas=False):
lti_to_files = defaultdict(set)
for storage_metadata in global_storage_metadata:
for lti, fname in storage_metadata.items():
lti_to_files[lti].add(fname)
file_load = defaultdict(int)
out = {}
for lti, file_candidates in lti_to_files.items():
candidates = sorted(file_candidates)
selected_main_file = min(candidates, key=lambda f: file_load[f])
file_load[selected_main_file] += 1
if save_replicas:
lti_main = replace(lti, replica_id=0)
out[lti_main] = selected_main_file
replica_id = 1
for fname in candidates:
if fname == selected_main_file:
continue
lti_replica = replace(lti, replica_id=replica_id)
out[lti_replica] = fname
replica_id += 1
else:
out[lti] = selected_main_file
return out
def dedup_tensor(
local_state_dict, local_storage_metadata, global_storage_metadata
):
"""
Dedup the replicated tensor in local state_dict.
Args:
local_state_dict(Dict[str, paddle.Tensor]): The state_dict of current rank.
local_storage_metadata(Dict[LocalTensorIndex, str]): The storage metadata of current rank.
global_storage_metadata(Dict[LocalTensorIndex, str]): The final storage metadata of all ranks.
Examples:
In rank0, local_state_dict:{"w1": t1_0, "w2": t2}, local_storage_metadata:{LocalTensorIndex("w1", (0,0)): "0_0.distcp", LocalTensorIndex("w2", (0,0)): "0_0.distcp"},
in rank1, local_state_dict:{"w1": t1_1, "w2": t2}, local_storage_metadata:{LocalTensorIndex("w1", (1,0)): "1_0.distcp", LocalTensorIndex("w2", (0,0)): "1_0.distcp"},
global_storage_metadata:{LocalTensorIndex("w1", (0,0)): "0_0.distcp", LocalTensorIndex("w1", (1,0)): "1_0.distcp", LocalTensorIndex("w2", (0, 0)): "0_0.distcp"}.
w2 is replicated in rank0 and rank1. We save it in rank0 as default thus need to remove it in other ranks.
Finally, the local_state_dict:{"w1": t1_1, "w2": t2} in rank1 update to {"w1": t1_1}.
"""
for tensor_index, file_name in global_storage_metadata.items():
rank = int(file_name.split(".")[0].split("_")[0])
if (
tensor_index in local_storage_metadata
and rank != paddle.distributed.get_rank()
):
local_state_dict.pop(tensor_index.tensor_key)
def save_state_dict(
state_dict: dict[str, Tensor] | dict[str, ShardedWeight],
path: str,
process_group: Group | None = None,
coordinator_rank: int = 0,
unique_id: int | None = None,
async_save: bool = False,
safetensors: bool = False,
save_replicas: bool = False,
) -> None:
r"""
Save the state_dict of model to path.
Args:
state_dict(Dict[str, paddle.Tensor]): The state_dict to save.
path(str): The directory to save state_dict.
process_group(paddle.distributed.collective.Group): ProcessGroup to be used for cross-rank synchronization. Use the default process group which contains all cards.
coordinator_rank(int): The rank used to save non distributed values. Rank 0 is used by default.
unique_id(int): The unique id of checkpoint, used to distinguish between different checkpoint versions. Default is None, in which case the id 0 when save for the first time and increased by 1 each time when calling save_state_dict in the same path. If unique_id is given and there is already checkpoint with the same unique_id, it will be overrited.
async_save(bool): Async save the state_dict, default is False.
safetensors(bool): Whether to save using safetensors format. Default is False.
save_replicas (bool): Whether to save all tensor replicas (e.g., from different ranks) instead of only one deduplicated copy per tensor. Default is False.
Examples:
.. code-block:: pycon
>>> # doctest: +SKIP('run in distributed mode')
>>> import paddle
>>> import paddle.distributed as dist
>>> w1 = paddle.arange(32).reshape([4, 8])
>>> mesh = dist.ProcessMesh([0, 1])
>>> sharded_w1 = dist.shard_tensor(w1, mesh, [dist.Shard(0), dist.Replicate()])
>>> state_dict = {"w1": sharded_w1}
>>> dist.save_state_dict(state_dict, "./checkpoint")
>>> # doctest: -SKIP
"""
with paddle.base.dygraph.guard():
assert isinstance(state_dict, dict), (
f"The state_dict should be a dictionary.But now the type is {type(state_dict)}."
)
flat_state_dict, mapping = flatten_state_dict(state_dict)
if len(flat_state_dict) > 0:
for val in flat_state_dict.values():
assert isinstance(val, (paddle.Tensor, ShardedWeight)), (
f"The value of state_dict should be a paddle.Tensor or ShardedWeight, but got: {val}."
)
if not os.path.exists(path):
os.makedirs(path, exist_ok=True)
use_dist = True if paddle.distributed.get_world_size() > 1 else False
if use_dist and process_group is None and not is_initialized():
# Init the default global process group
paddle.distributed.init_parallel_env()
if unique_id is None:
max_unique_id = get_max_id(path)
logger.debug(f"Max unique id: {max_unique_id}")
if max_unique_id is None:
unique_id = 0
else:
unique_id = max_unique_id
else:
assert unique_id >= 0, f'{unique_id} should be >= 0'
if use_dist:
check_unique_id(unique_id, process_group)
file_suffix = "distcp" if not safetensors else "safetensors"
file_name = f"{paddle.distributed.get_rank()}_{unique_id}.{file_suffix}"
logger.debug(f"The checkpoint is saved to file_name:{file_name}")
metadata = Metadata()
local_state_dict = {}
local_state_dict_metadata = {}
local_storage_metadata = {}
global_shape = None
for key, val in flat_state_dict.items():
local_tensor, local_tensor_metadata = extract_tensor_metadata(val)
if local_tensor is None and local_tensor_metadata is None:
continue
local_state_dict[key] = local_tensor
local_state_dict_metadata[key] = local_tensor_metadata
global_offset = local_tensor_metadata.global_offset
is_flattened = local_tensor_metadata.is_flattened
flattened_range = local_tensor_metadata.flattened_range
local_shape = local_tensor_metadata.local_shape
local_storage_metadata[
LocalTensorIndex(
tensor_key=key,
global_offset=global_offset,
is_flattened=is_flattened,
flattened_range=flattened_range,
local_shape=local_shape,
)
] = file_name
global_state_dict_metadata = []
global_storage_metadata = []
global_flatten_mapping = []
if use_dist:
paddle.distributed.all_gather_object(
global_state_dict_metadata,
local_state_dict_metadata,
process_group,
)
paddle.distributed.all_gather_object(
global_storage_metadata, local_storage_metadata, process_group
)
paddle.distributed.all_gather_object(
global_flatten_mapping, mapping, process_group
)
else:
global_state_dict_metadata.append(local_state_dict_metadata)
global_storage_metadata.append(local_storage_metadata)
global_flatten_mapping.append(mapping)
metadata.state_dict_metadata = merge_state_dict_metadata(
global_state_dict_metadata
)
metadata.storage_metadata = balanced_dedup_key_in_dict(
global_storage_metadata, save_replicas=save_replicas
)
metadata.flat_mapping = dedup_key_in_dict(global_flatten_mapping)
logger.debug(f"metadata:{metadata}")
write_to_file_if_empty(
metadata, os.path.join(path, f"{unique_id}.metadata")
)
if not save_replicas:
dedup_tensor(
local_state_dict,
local_storage_metadata,
metadata.storage_metadata,
)
if async_save:
cpu_state_dict = copy_dict_to_cpu(local_state_dict)
clear_async_save_task_queue()
attempt = 0
ctx = multiprocessing.get_context("spawn")
def start_process():
nonlocal attempt
try:
p = ctx.Process(
target=paddle.save,
args=(cpu_state_dict, os.path.join(path, file_name)),
kwargs={'safetensors': safetensors},
)
p.start()
return p
except Exception as e:
logger.error(
f"Attempt {attempt + 1} failed with error: {e}"
)
attempt += 1
time.sleep(1)
return start_process()
p = start_process()
async_save_queue.append(p)
else:
paddle.save(
local_state_dict,
os.path.join(path, file_name),
safetensors=safetensors,
)