File size: 2,505 Bytes
c9ac3c3 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 | # Copyright 2024 Bytedance Ltd. and/or its affiliates
#
# 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.
"""
Contains a resharding manager that binds weights from FSDP zero3 to XPerfGPT
"""
from torch.distributed.device_mesh import DeviceMesh
from ...protocol import DataProto, all_gather_data_proto
from ...utils.ulysses import get_ulysses_sequence_parallel_group, set_ulysses_sequence_parallel_group
from .base import BaseShardingManager
class FSDPUlyssesShardingManager(BaseShardingManager):
"""
Sharding manager to support data resharding when using FSDP + Ulysses
"""
def __init__(self, device_mesh: DeviceMesh):
super().__init__()
self.device_mesh = device_mesh
def __enter__(self):
if self.device_mesh is not None:
self.prev_sp_group = get_ulysses_sequence_parallel_group()
set_ulysses_sequence_parallel_group(self.device_mesh["sp"].get_group())
def __exit__(self, exc_type, exc_value, traceback):
if self.device_mesh is not None:
set_ulysses_sequence_parallel_group(self.prev_sp_group)
def preprocess_data(self, data: DataProto) -> DataProto:
"""
AllGather data from sp region
This is because the data is first sharded along the FSDP dimension as we utilize the DP_COMPUTE
In Ulysses, we need to make sure the same data is used across a SP group
"""
if self.device_mesh is not None:
sp_size = self.device_mesh["sp"].size()
sp_group = self.device_mesh["sp"].get_group()
all_gather_data_proto(data, size=sp_size, group=sp_group)
return data
def postprocess_data(self, data: DataProto) -> DataProto:
"""
Split the data to follow FSDP partition
"""
if self.device_mesh is not None:
sp_size = self.device_mesh["sp"].size()
sp_rank = self.device_mesh["sp"].get_local_rank()
data = data.chunk(chunks=sp_size)[sp_rank]
return data
|