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paddlepaddle--paddle/python/paddle/distributed/passes/auto_parallel_sync_shared_params.py
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2026-07-13 12:40:42 +08:00

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# Copyright (c) 2024 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 logging
import paddle
import paddle.distributed as dist
from paddle.base.core import TensorDistAttr
from paddle.base.executor import global_scope
from paddle.base.framework import auto_complete_op_role
from paddle.distributed.auto_parallel.static.process_group import (
new_process_group,
)
from paddle.distributed.auto_parallel.static.utils import (
get_pp_stage_by_process_mesh,
)
from paddle.distributed.fleet.meta_optimizers.common import OpRole
from paddle.static.pir_io import get_pir_parameters
from ..auto_parallel.static.utils import (
get_logger,
)
from .pass_base import PassBase, register_pass
logger = get_logger(logging.INFO)
@register_pass("auto_parallel_sync_shared_params")
class AutoParallelSyncSharedParamsPass(PassBase):
def __init__(self):
super().__init__()
self.params_maybe_shared = []
self.src_ranks = []
self.dst_ranks = []
self.comm_group = {}
def _check_self(self):
pipeline_strategy = self.get_attr('pipeline_strategy')
if (not pipeline_strategy.enable) or pipeline_strategy.pp_degree <= 1:
return False
return True
def _check_conflict(self, other_pass):
return True
def _find_fist_opt_user(self, main_program):
for op in main_program.global_block().ops:
if op.op_role == 2:
return op
def _get_comm_group(self, ranks=[]):
ranks = sorted(ranks)
if tuple(ranks) in self.comm_group:
return self.comm_group[tuple(ranks)]
# The communication group of this `all_reduce` op satisfies len (ranks)==2.
# When `force_new_group=False` is set, the `send&recv` group will be returned,
# At this point, `all_reduce` and `send&recv` share the same group, and
# the process will hang up.
group = new_process_group(ranks, force_new_group=True)
self.comm_group[tuple(ranks)] = group.id
return group.id
def sync_shared_parameters(self, main_program, startup_program):
if not self._check_self():
logger.info(
"AutoParallelSyncSharedParamsPass need support pipeline parallel, skip pass."
)
return []
new_shared_params = []
params, _ = get_pir_parameters(main_program)
for param in params:
users = param.all_used_ops()
for user_op in users:
if user_op.name() == "dist_op.reshard":
reshard_op = user_op
dist_attr = reshard_op.dist_attr
src_dist_attr = dist_attr.operand(0).as_tensor_dist_attr()
dst_dist_attr = dist_attr.result(0).as_tensor_dist_attr()
src_mesh = src_dist_attr.process_mesh
dst_mesh = dst_dist_attr.process_mesh
# Shared parameter needs reshard on diff stage.
pipeline_strategy = self.get_attr('pipeline_strategy')
pp_degree = pipeline_strategy.pp_degree
src_stage = get_pp_stage_by_process_mesh(
src_mesh, pp_degree
)
dst_stage = get_pp_stage_by_process_mesh(
dst_mesh, pp_degree
)
if (
src_stage is None
or dst_stage is None
or src_stage == dst_stage
):
continue
# Get shared parameter name
param_name = param.get_defining_op().str_attr(
'parameter_name'
)
# Add shared parameter builtin.parameter with "shared_" prefix.
with (
auto_complete_op_role(main_program, OpRole.Forward),
paddle.static.program_guard(
main_program, startup_program
),
):
shared_param = paddle.pir.core.create_parameter(
dtype=param.dtype,
shape=param.shape,
name="shared_" + param_name,
process_mesh=dst_mesh,
placements=src_dist_attr.placements,
initializer=paddle.nn.initializer.Constant(value=0),
)
main_program.set_parameters_from(startup_program)
# Record new shared parameter.
new_shared_params.append("shared_" + param_name)
# Set value for new shared parameter.
concrete_program = self.get_attr("concrete_program")
dy_params = concrete_program.parameters[0]
dy_param = None
for tmp_param in dy_params:
if tmp_param.name == param_name:
dy_param = tmp_param
break
assert dy_param is not None, (
f"The parameter {param_name} was not found in the concrete_degram"
)
new_dist_attr = TensorDistAttr()
new_dist_attr.process_mesh = dst_mesh
new_dist_attr.dims_mapping = src_dist_attr.dims_mapping
with paddle.no_grad():
dy_shared_param = paddle.base.core.reshard(
dy_param, new_dist_attr
)
paddle.device.synchronize()
if dy_shared_param._is_initialized():
pir_shared_param = (
global_scope()
.var("shared_" + param_name)
.get_tensor()
)
pir_shared_param._share_data_with(
dy_shared_param.get_tensor().get_tensor()
)
# record in params_maybe_shared
self.params_maybe_shared.append(
{
'src_mesh': src_mesh,
'dst_mesh': dst_mesh,
'src_dist_attr': src_dist_attr,
'dst_dist_attr': dst_dist_attr,
'param_name': param_name,
}
)
# New shared parameter must has same dist_attr with shared parameter
new_src_dist_attr = (
paddle.base.libpaddle.pir.create_tensor_dist_attribute(
dst_dist_attr.process_mesh,
src_dist_attr.dims_mapping,
src_dist_attr.partial_status,
)
)
if new_src_dist_attr == dst_dist_attr:
# Remove useless reshared op.
reshard_op.result(0).replace_all_uses_with(shared_param)
reshard_op.erase()
else:
# Update reshard op dist_attr.
reshard_op.dist_attr = (
paddle.base.libpaddle.pir.create_op_dist_attribute(
dst_mesh,
[new_src_dist_attr],
[dst_dist_attr],
-1,
)
)
reshard_op.operand(0).set_source(shared_param)
self.src_ranks.extend(src_mesh.process_ids)
self.dst_ranks.extend(dst_mesh.process_ids)
if len(self.params_maybe_shared) == 0:
logger.info("No parameter need to share, skip pass.")
return []
# Must initialize the redundant communication group for the allreduce op here.
# Otherwise, it will hang during gradient synchronization.
for idx in range(len(self.src_ranks)):
rank_1 = self.src_ranks[idx]
rank_2 = self.dst_ranks[idx]
new_process_group(sorted([rank_1, rank_2]))
self._get_comm_group([rank_1, rank_2])
return new_shared_params
def sync_shared_parameter_gradient(
self, main_program, startup_program, params_grads
):
if not self._check_self():
logger.info(
"AutoParallelSyncSharedParamsPass need support pipeline parallel, skip pass."
)
return params_grads
if len(self.params_maybe_shared) == 0:
logger.info("No parameter need to share, skip pass.")
return params_grads
# Only support one shared parameter.
# TODO: support more shared parameters
assert len(self.params_maybe_shared) == 1, (
"Currently, only one shared parameter is supported, and it cannot support more at the moment."
)
cur_rank = paddle.distributed.get_rank()
if cur_rank not in self.src_ranks and cur_rank not in self.dst_ranks:
return params_grads
pre_name = ""
if cur_rank in self.dst_ranks:
pre_name = "shared_"
for param_mess in self.params_maybe_shared:
param_name = pre_name + param_mess['param_name']
src_mesh_ids = param_mess['src_mesh'].process_ids
dst_mesh_ids = param_mess['dst_mesh'].process_ids
# Get (param, grad) value
param_value = main_program.get_parameter_value_by_name(param_name)
grad_idx = None
for p_idx, (p_param, _) in enumerate(params_grads):
if p_param.is_same(param_value):
grad_idx = p_idx
break
assert grad_idx is not None, (
f"Parameter {param_name} not found in params_grades, unable to find corresponding gradient value."
)
grad_value = params_grads[p_idx][1]
# Create allreduce op comm group.
cur_rank = paddle.distributed.get_rank()
if cur_rank in self.src_ranks:
idx = src_mesh_ids.index(cur_rank)
peer_rank = dst_mesh_ids[idx]
if cur_rank in self.dst_ranks:
idx = dst_mesh_ids.index(cur_rank)
peer_rank = src_mesh_ids[idx]
ar_group_id = self._get_comm_group([cur_rank, peer_rank])
# Insert allreduce op in the end of backward.
insert_pos = self._find_fist_opt_user(main_program)
paddle.pir.set_insertion_point(insert_pos)
# Build allreduce op to sync gradient.
with auto_complete_op_role(main_program, OpRole.Backward):
allreduce_val = paddle._C_ops.all_reduce(
grad_value,
ar_group_id,
dist.ReduceOp.SUM,
)
allreduce_val.update_dist_attr(grad_value.dist_attr())
allreduce_op = allreduce_val.get_defining_op()
# Update all_used_ops
for user in grad_value.all_used_ops():
if user.name() == "pd_op.all_reduce":
continue
for idx, operand in enumerate(user.operands()):
if user.operand_source(idx).is_same(grad_value):
user.operand(idx).set_source(allreduce_val)
# Update (param, grad) value
params_grads[p_idx] = (param_value, allreduce_val)
return params_grads
def _apply_single_impl(self, main_program, startup_program, context):
return