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ColossalAI/colossalai/auto_parallel/passes/comm_metainfo_pass.py

125 lines
5.0 KiB

from typing import Dict
import torch
from torch.fx import GraphModule
from torch.fx.node import Node
from colossalai.auto_parallel.meta_profiler import ShardMetaInfo
from colossalai.auto_parallel.passes.runtime_apply_pass import runtime_apply, runtime_comm_spec_apply
from colossalai.auto_parallel.tensor_shard.sharding_strategy import MemoryCost, TrainCycleItem
from colossalai.tensor.comm_spec import CommSpec
from colossalai.tensor.shape_consistency import ShapeConsistencyManager
from colossalai.tensor.sharding_spec import ShardingSpec
shape_consistency_manager = ShapeConsistencyManager()
def _construct_shard_meta_info(
node: Node, origin_sharding_spec: ShardingSpec, target_sharding_spec: ShardingSpec
) -> ShardMetaInfo:
# get comm_action_sequence and total_cost from shape_consistency_manager
_, comm_action_sequence, total_cost = shape_consistency_manager.shape_consistency(
origin_sharding_spec, target_sharding_spec
)
meta_info = ShardMetaInfo()
# NOTE: the cost in shape_consistency_manager.mem_cost is the count in number of numel
# get mem cost for ShardMetaInfo
mem_cost = shape_consistency_manager.mem_cost(comm_action_sequence)
# extract user that has _meta_data and extract element length
input_node = next(n for n in node._input_nodes if hasattr(n, "_meta_data"))
element_length = input_node._meta_data.element_size()
mem_cost.fwd.activation *= element_length
mem_cost.fwd.temp *= element_length
mem_cost.bwd.activation *= element_length
mem_cost.bwd.temp *= element_length
mem_cost.total.activation *= element_length
meta_info.memory_cost = mem_cost
# get computation cost for ShardMetaInfo
meta_info.compute_cost = TrainCycleItem(
total_cost["forward"] * element_length,
total_cost["backward"] * element_length,
total_cost["total"] * element_length,
)
# get tensor shape for ShardMetaInfo
origin_sharding_spec: ShardingSpec
target_sharding_spec: ShardingSpec
input_shape = origin_sharding_spec.get_sharded_shape_per_device()
output_shape = target_sharding_spec.get_sharded_shape_per_device()
meta_info.fwd_in = [torch.rand(input_shape, device="meta")]
meta_info.fwd_buffer = []
meta_info.fwd_out = [torch.rand(output_shape, device="meta")]
return meta_info
def _runtime_apply_meta_info(node: Node, origin_spec_dict, sharding_spec_dict) -> ShardMetaInfo:
"""
This method is used to construct `MetaInto` for shape consistency node
"""
# extract node index and user node index
args = node.args
node_index, user_node_index = args[3], args[4]
origin_sharding_spec, target_sharding_spec = (
origin_spec_dict[node_index],
sharding_spec_dict[node_index][user_node_index],
)
return _construct_shard_meta_info(node, origin_sharding_spec, target_sharding_spec)
def _runtime_comm_spec_apply_meta_info(node: Node, comm_actions_dict: Dict) -> ShardMetaInfo:
# extract node_index and op_data_name
node_index, op_data_name = node.args[2], node.args[3]
comm_action = comm_actions_dict[node_index][op_data_name]
if isinstance(comm_action.comm_spec, CommSpec):
# this case is for all_reduce, there will be no memory cost
meta_info = ShardMetaInfo()
meta_info.memory_cost = TrainCycleItem(MemoryCost(), MemoryCost(), MemoryCost)
output_node = next(n for n in node.users if hasattr(n, "_meta_data"))
element_length = output_node._meta_data.element_size()
total_cost = comm_action.comm_spec.get_comm_cost()
meta_info.compute_cost = TrainCycleItem(
total_cost["forward"] * element_length,
total_cost["backward"] * element_length,
total_cost["total"] * element_length,
)
input_shape = output_shape = comm_action.comm_spec.sharding_spec.get_sharded_shape_per_device()
meta_info.fwd_in = [torch.rand(input_shape, device="meta")]
meta_info.fwd_buffer = []
meta_info.fwd_out = [torch.rand(output_shape, device="meta")]
else:
# this case will be handled by shape consistency manager
origin_sharding_spec, target_sharding_spec = (
comm_action.comm_spec["src_spec"],
comm_action.comm_spec["tgt_spec"],
)
meta_info = _construct_shard_meta_info(node, origin_sharding_spec, target_sharding_spec)
return meta_info
def comm_metainfo_pass(
gm: GraphModule, sharding_spec_dict: Dict, origin_spec_dict: Dict, comm_actions_dict: Dict
) -> GraphModule:
"""
The method manages all the metainfo of the communication node (run_time_apply, runtime_comm_spec_apply) in the graph.
"""
for node in gm.graph.nodes:
if node.target == runtime_apply:
setattr(node, "best_strategy_info", _runtime_apply_meta_info(node, origin_spec_dict, sharding_spec_dict))
elif node.target == runtime_comm_spec_apply:
setattr(node, "best_strategy_info", _runtime_comm_spec_apply_meta_info(node, comm_actions_dict))
else:
pass
return gm