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ColossalAI/colossalai/auto_parallel/passes/comm_metainfo_pass.py

114 lines
5.1 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