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paddlepaddle--paddle/python/paddle/distributed/fleet/meta_optimizers/raw_program_optimizer.py
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2026-07-13 12:40:42 +08:00

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# Copyright (c) 2021 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
import os
import paddle
from paddle import static
from paddle.base import core
from paddle.framework.ir import apply_build_strategy
from paddle.utils import unique_name
from .common import (
OP_ROLE_KEY,
OP_ROLE_VAR_KEY,
CollectiveHelper,
OpRole,
is_backward_op,
is_loss_grad_op,
is_optimizer_op,
)
from .meta_optimizer_base import MetaOptimizerBase
def evaluate_flag_apply_pass_to_program(val: str) -> bool:
val = val.lower()
if val in ('false', 'off', '0'):
return False
else:
return True
class RawProgramOptimizer(MetaOptimizerBase):
def __init__(self, optimizer):
super().__init__(optimizer)
self.inner_opt = optimizer
self.meta_optimizers_white_list = [
"RecomputeOptimizer",
"AMPOptimizer",
"GradientMergeOptimizer",
"LambOptimizer",
"LarsOptimizer",
"DGCOptimizer",
"LocalSGDOptimizer",
]
self.meta_optimizers_black_list = []
self.global_ring_id = 0
def _set_basic_info(
self, loss, role_maker, user_defined_optimizer, user_defined_strategy
):
super()._set_basic_info(
loss, role_maker, user_defined_optimizer, user_defined_strategy
)
self.without_graph_optimization = (
user_defined_strategy.without_graph_optimization
)
self.fuse_all_reduce_ops = user_defined_strategy.fuse_all_reduce_ops
if self.fuse_all_reduce_ops:
self.fuse_grad_size_in_num = (
user_defined_strategy.fuse_grad_size_in_num
)
self.calc_comm_same_stream = (
user_defined_strategy._calc_comm_same_stream
)
self.sync_before_allreduce = os.environ.get(
'FLAGS_sync_before_allreduce', None
)
def _can_apply(self):
if not self.role_maker._is_collective:
return False
if self.user_defined_strategy.tensor_parallel:
return False
if self.user_defined_strategy.sharding:
return False
if self.without_graph_optimization:
return True
return False
def _disable_strategy(self, dist_strategy):
dist_strategy.without_graph_optimization = False
def _enable_strategy(self, dist_strategy, context):
dist_strategy.without_graph_optimization = True
def _broadcast_params(self, ring_id):
block = self.startup_program.global_block()
param = None
for param in block.iter_parameters():
if param.is_distributed:
continue
block.append_op(
type='broadcast',
inputs={'x': param},
outputs={'out': param},
attrs={
'ring_id': ring_id,
'root': 0,
OP_ROLE_KEY: OpRole.Forward,
},
)
if not param:
return # no parameter on this device
block.append_op(
type='c_sync_comm_stream',
inputs={'X': param},
outputs={'Out': param},
attrs={'ring_id': ring_id, OP_ROLE_KEY: OpRole.Forward},
)
def _get_process_group_info(self):
# global ring info
self.global_endpoints = self.endpoints
self.global_rank = self.rank
self.global_nranks = self.nranks
def _init_process_group(self):
self._get_process_group_info()
collective_helper = CollectiveHelper(self.role_maker, wait_port=False)
# Create global ring for all gpus (ring_id = 0)
collective_helper._init_communicator(
self.startup_program,
self.current_endpoint,
self.global_endpoints,
self.global_rank,
self.global_ring_id,
True,
self.global_ring_id,
True,
)
self._broadcast_params(self.global_ring_id)
def minimize_impl(
self, loss, startup_program=None, parameter_list=None, no_grad_set=None
):
self.endpoints = self.role_maker._get_trainer_endpoints()
self.current_endpoint = self.endpoints[self.role_maker._worker_index()]
self.rank = self.role_maker._worker_index()
self.nranks = self.role_maker._worker_num()
if startup_program is None:
startup_program = static.default_startup_program()
self.startup_program = startup_program
block = loss.block
program = block.program
self.main_program = program
optimize_ops, params_grads = self.inner_opt.minimize(
loss, startup_program, parameter_list, no_grad_set
)
# Not apply pass only when FLAGS_apply_pass_to_program explicitly set to False
is_apply_pass_to_program = os.environ.get(
'FLAGS_apply_pass_to_program', '1'
)
if evaluate_flag_apply_pass_to_program(is_apply_pass_to_program):
pass_attrs = {"use_cuda": True}
build_strategy = self.user_defined_strategy.build_strategy._copy()
build_strategy.fuse_all_optimizer_ops = False
build_strategy.fuse_all_reduce_ops = False
apply_build_strategy(
self.main_program,
self.startup_program,
build_strategy,
pass_attrs,
)
self.main_program._pass_applied = True
if self.nranks == 1:
return optimize_ops, params_grads
self._init_process_group()
self.main_program = program
if self.nranks > 1:
self._transpile_main_program(loss)
return optimize_ops, params_grads
def _find_gradient_merge_block(self):
GRAD_MERGE_COND_NAME = "grad_merge_cond_name"
gm_cond_var_name = None
for op in self.main_program.global_block().ops:
if GRAD_MERGE_COND_NAME not in op.attr_names:
continue
if gm_cond_var_name is None:
gm_cond_var_name = op.attr(GRAD_MERGE_COND_NAME)
else:
assert gm_cond_var_name == op.attr(GRAD_MERGE_COND_NAME), (
"multiple gradient merge condition found"
)
if gm_cond_var_name is None:
return None
cond_op = (
None # false_fn of gm is None, so we should only find one block
)
for op in self.main_program.global_block().ops:
if op.type != 'conditional_block' or 'Cond' not in op.input_names:
continue
cond_vars = op.input('Cond')
if not cond_vars or cond_vars[0] != gm_cond_var_name:
continue
assert cond_op is None, "multiple gradient merge block found"
cond_op = op
assert cond_op is not None, "cannot find gradient merge block"
return cond_op._block_attr("sub_block")
def _insert_allreduce_ops_for_gm(self, gm_block):
block = self.main_program.global_block()
first_optimize_op_idx = None
for i, op in reversed(list(enumerate(gm_block.ops))):
if is_backward_op(op) and first_optimize_op_idx is None:
first_optimize_op_idx = i + 1
break
if first_optimize_op_idx is None:
first_optimize_op_idx = 0
param_vars = []
grad_vars = []
for op in block.ops:
if is_backward_op(op) and OP_ROLE_VAR_KEY in op.attr_names:
op_role_var = op.attr(OP_ROLE_VAR_KEY)
assert len(op_role_var) % 2 == 0
for i in range(0, len(op_role_var), 2):
param = block.var(op_role_var[i])
grad = block.var(op_role_var[i + 1])
if param.is_distributed:
continue
param_vars.append(param)
grad_vars.append(grad)
if not grad_vars:
return
gm_block._insert_op(
first_optimize_op_idx,
type="c_sync_calc_stream",
inputs={'X': grad_vars[0]},
outputs={'Out': grad_vars[0]},
attrs={OP_ROLE_KEY: OpRole.Backward},
)
insert_op_num = 1
ring_id = self.global_ring_id
# NOTE: can perform fuse allreduce inside the loop in the future
for i, (p, g) in enumerate(zip(param_vars, grad_vars)):
gm_block._insert_op(
first_optimize_op_idx + insert_op_num,
type="all_reduce",
inputs={'x': g},
outputs={'out': g},
attrs={
'ring_id': ring_id,
'reduce_type': paddle.distributed.ReduceOp.SUM,
OP_ROLE_KEY: OpRole.Backward,
},
)
insert_op_num += 1
gm_block._insert_op(
first_optimize_op_idx + insert_op_num,
type="c_sync_comm_stream",
inputs={'X': grad_vars},
outputs={'Out': grad_vars},
attrs={
'ring_id': ring_id,
OP_ROLE_KEY: OpRole.Backward,
},
)
def _transpile_main_program(self, loss):
self._insert_loss_grad_ops(loss)
gm_block = self._find_gradient_merge_block()
if gm_block is not None:
# TODO(zjl): support fuse allreduce
self._insert_allreduce_ops_for_gm(gm_block)
return
if self.fuse_all_reduce_ops and self.fuse_grad_size_in_num > 1:
self._allreduce_fusion_program()
else:
self._insert_allreduce_ops()
def _insert_loss_grad_ops(self, loss):
"""
In order to keep the learning rate consistent in different numbers of
training workers, we scale the loss grad by the number of workers
"""
block = self.main_program.global_block()
for idx, op in reversed(list(enumerate(block.ops))):
if is_loss_grad_op(op):
loss_grad_var = block.vars[op.output_arg_names[0]]
block._insert_op(
idx + 1,
type='scale',
inputs={'X': loss_grad_var},
outputs={'Out': loss_grad_var},
attrs={
'scale': 1.0 / self.nranks,
OP_ROLE_KEY: OpRole.Backward,
},
)
def _insert_allreduce_ops(self):
block = self.main_program.global_block()
ring_id = self.global_ring_id
grad = None
grad_vars = []
for idx, op in reversed(list(enumerate(block.ops))):
if is_backward_op(op) and OP_ROLE_VAR_KEY in op.attr_names:
op_role_var = op.attr(OP_ROLE_VAR_KEY)
if len(op_role_var) == 0:
continue
assert len(op_role_var) % 2 == 0
offset = 1
for i in range(0, len(op_role_var), 2):
param_name = op_role_var[i]
param = block.var(param_name)
grad_name = op_role_var[i + 1]
grad = block.var(grad_name)
if param.is_distributed:
continue
block._insert_op(
idx + offset,
type='all_reduce',
inputs={'x': grad},
outputs={'out': grad},
attrs={
'ring_id': ring_id,
'reduce_type': paddle.distributed.ReduceOp.SUM,
OP_ROLE_KEY: OpRole.Backward,
},
)
if grad is None:
return
# This function helps reduce the number of allreduce by integrating op, which can save communication time.
# to use allreduce fuse, follow these codes:
# strategy = paddle.distributed.fleet.DistributedStrategy()
# strategy.without_graph_optimization = True
# strategy.fuse_all_reduce_ops = True
# strategy.calc_comm_same_stream = False
# strategy.fuse_grad_size_in_num = 8
def _allreduce_fusion_program(self):
block = self.main_program.global_block()
ring_id = self.global_ring_id
param_grads = []
first_backward_idx = -1
# find all grad params
for idx, op in enumerate(block.ops):
if first_backward_idx == -1 and is_backward_op(op):
first_backward_idx = idx
if is_backward_op(op) and OP_ROLE_VAR_KEY in op.attr_names:
op_role_var = op.attr(OP_ROLE_VAR_KEY)
if len(op_role_var) == 0:
continue
assert len(op_role_var) % 2 == 0, (
"vars need to be one param var followed by one grad var, "
"but got odd number of vars"
)
for i in range(0, len(op_role_var), 2):
param_name = op_role_var[i]
param = block.var(param_name)
grad_name = op_role_var[i + 1]
grad = block.var(grad_name)
if param.is_distributed:
continue
param_grads.append((param, grad))
outputs_name_to_idx = self.__get_outputs_name_to_idx(
first_backward_idx, block
)
# structure of grad_param_segments is
# [([grad0, grad1], [param0, param1]), ([grad2, grad3], [param2, param3])]
# each entry of the list is a tuple stores the grads segment list and
# the corresponding params segment list
# its type is: dict[dtype, list[tuple[list[grad], list[param]]]]
grad_param_segments_by_dtype = {}
# split the grad based on dtype and fused size
for param, grad in param_grads:
if grad.dtype not in grad_param_segments_by_dtype:
grad_param_segments_by_dtype[grad.dtype] = [([], [])]
grad_segment, param_segment = grad_param_segments_by_dtype[
grad.dtype
][-1]
if len(param_segment) == self.fuse_grad_size_in_num:
grad_param_segments_by_dtype[grad.dtype].append(([], []))
grad_segment, param_segment = grad_param_segments_by_dtype[
grad.dtype
][-1]
param_segment.append(param)
grad_segment.append(grad)
grad_param_segments = []
for _, group in grad_param_segments_by_dtype.items():
grad_param_segments.extend(group)
if len(grad_param_segments) == 0:
return
# because the regroup operation make the relative order invalid,
# we need to reorder these fuse group by after_idx
def get_after_idx_of_fuse_group(grad_param_segments):
grad_segment, param_segment = grad_param_segments
return max([outputs_name_to_idx[grad][1] for grad in grad_segment])
grad_param_segments.sort(key=get_after_idx_of_fuse_group)
fused_vars = [None] * len(grad_param_segments)
for i in range(len(grad_param_segments) - 1, -1, -1):
# travers the grad_param_segments in backward
# not to use reversed since needs the absolute index value
grad_segment, param_segment = grad_param_segments[i]
# insert coalesce tensor
fused_var = block.create_var(
name=unique_name.generate(
f'FusedOutput_{grad_segment[0].name}'
),
dtype=grad_segment[0].dtype,
persistable=False,
stop_gradient=True,
)
fused_vars[i] = fused_var
after_idx = max(
[outputs_name_to_idx[grad][1] for grad in grad_segment]
)
block._insert_op_without_sync(
after_idx + 1,
type='all_reduce',
inputs={'x': fused_var},
outputs={'out': fused_var},
attrs={
'ring_id': ring_id,
'reduce_type': paddle.distributed.ReduceOp.SUM,
OP_ROLE_KEY: OpRole.Backward,
},
)
if not self.calc_comm_same_stream and self.sync_before_allreduce:
block._insert_op_without_sync(
after_idx + 1,
type='c_sync_calc_stream',
inputs={'X': fused_var},
outputs={'Out': fused_var},
attrs={OP_ROLE_KEY: OpRole.Backward},
)
idx = 0
if not self.calc_comm_same_stream and not self.sync_before_allreduce:
for i in range(len(grad_param_segments)):
while (
block.ops[idx].type != 'c_allreduce_sum'
and (
not (
block.ops[idx].type == 'all_reduce'
and block.ops[idx].attr('reduce_type')
== paddle.distributed.ReduceOp.SUM
)
)
) or fused_vars[i].name not in block.ops[idx].input_arg_names:
idx += 1
grad_segment, param_segment = grad_param_segments[i]
for grad in grad_segment:
block._insert_op_without_sync(
idx + 1,
type='depend',
inputs={'X': grad, 'Dep': fused_vars[i]},
outputs={'Out': grad},
)
idx += 1
# update the outputs_name_to_idx after insertion of sync/allreduce ops
outputs_name_to_idx = self.__get_outputs_name_to_idx(
first_backward_idx, block
)
# the before_idx is not guaranteed sorted, therefore we have to find the
# topology to insert the coalesce ops
pos_for_coalesce = {}
for i in range(len(grad_param_segments) - 1, -1, -1):
# We separate the insertion of coalesce op and the insertion of sync/allreduce op,
# since that the coalesce op's insertion may invalidate the outputs_name_to_idx
grad_segment, param_segment = grad_param_segments[i]
before_idx = len(block.ops)
for grad in outputs_name_to_idx:
before_idx = min(before_idx, outputs_name_to_idx[grad][0])
pos_for_coalesce[i] = before_idx
# insert the coalesce op based on the sorted before_idx
pos_for_coalesce = sorted(
pos_for_coalesce.items(),
key=lambda kv: (kv[1], kv[0]),
reverse=True,
)
for i, before_idx in pos_for_coalesce:
grad_segment, param_segment = grad_param_segments[i]
fused_var = fused_vars[i]
block._insert_op_without_sync(
before_idx,
type="coalesce_tensor",
inputs={"Input": param_segment},
outputs={"Output": grad_segment, "FusedOutput": fused_var},
attrs={
"copy_data": False,
"use_align": True,
"dtype": grad_segment[0].dtype,
OP_ROLE_KEY: OpRole.Backward,
},
)
if self.calc_comm_same_stream or not self.sync_before_allreduce:
block._sync_with_cpp()
return
# insert the sync comm op
for idx, op in enumerate(block.ops):
if is_optimizer_op(op):
block._insert_op_without_sync(
idx,
type='c_sync_comm_stream',
inputs={'X': fused_vars},
outputs={'Out': fused_vars},
attrs={'ring_id': ring_id, OP_ROLE_KEY: OpRole.Backward},
)
break
block._sync_with_cpp()
def __get_outputs_name_to_idx(self, first_backward_idx, block):
# Each item of outputs_name_to_idx is a pair of idx.
# The first entry of this pair is the idx of the first op generates the grad,
# which is used to indicate the position to insert coalesce op.
# The second entry of this pair is the idx of the last op generates the grad,
# which is used to indicate the position to insert sync and allreduce op.
outputs_name_to_idx = {}
for idx in range(first_backward_idx, len(block.ops)):
op = block.ops[idx]
if is_optimizer_op(op):
break
for name in op.output_arg_names:
if name == core.kEmptyVarName():
continue
var = block.var(name)
if not outputs_name_to_idx.get(var):
# if the grad only be generated by one op
# the first idx and the last ids are identical
outputs_name_to_idx[var] = (idx, idx)
else:
outputs_name_to_idx[var] = (
outputs_name_to_idx[var][0],
idx,
)
return outputs_name_to_idx