ColossalAI/colossalai/auto_parallel/solver/operator_handler.py

93 lines
4.4 KiB
Python

from webbrowser import Opera
import torch
import torch.nn as nn
from abc import ABC, abstractmethod
from torch.fx.node import Node
from typing import Dict, List
from colossalai.device.device_mesh import DeviceMesh
from colossalai.tensor.shape_consistency import ShapeConsistencyManager
from colossalai.tensor.sharding_spec import ShardingSpec
from .sharding_strategy import StrategiesVector
__all__ = ['OperatorHandler']
class OperatorHandler(ABC):
'''
The OperatorHandler is an abstract class used to generate every possible strategies for a operator node.
Argument:
input_node(Node): the input node in node argument list.
input_index(int): the index of input node in the node argument list.
weight(torch.Tensor): Weight of the node.
output_node(Node): Output_node is the output of the node.
device_mesh(DeviceMesh): A logical view of a physical mesh.
strategies_vector(StrategiesVector): all the strategies generated in this handler will be recorded into the strategies_vector.
shape_consistency_manager(ShapeConsistencyManager): ShapeConsistencyManager will give the resharding costs of the different sharding specs.
'''
def __init__(self, node: Node, device_mesh: DeviceMesh, strategies_vector: StrategiesVector,
shape_consistency_manager: ShapeConsistencyManager):
self.node = node
self.predecessor_node = list(node._input_nodes.keys())
self.successor_node = list(node.users.keys())
self.device_mesh = device_mesh
self.strategies_vector = strategies_vector
self.shape_consistency_manager = shape_consistency_manager
# find the module and its parameters associated with this node
# this can be used to compute the compute/communication/sharding cost
if self.node.op == 'call_module':
module = node.graph.owning_module.get_submodule(node.target)
named_parameters = list(module.named_parameters(recurse=False))
# convert named parameters from list to dict
named_parameters = {k: v for k, v in named_parameters}
else:
module = None
named_parameters = None
self.module = module
self.module_named_parameters = named_parameters
@abstractmethod
def register_strategy(self) -> StrategiesVector:
"""
Register
"""
pass
def _generate_sharding_spec(self, tensor: torch.Tensor, dim_partition_dict: Dict[int, List[int]]) -> ShardingSpec:
"""
Generate the sharding spec of the tensor based on the given dim_partition_dict
where the key is the tensor dimension and the value is the mesh dimension for sharding.
"""
sharding_spec = ShardingSpec(device_mesh=self.device_mesh,
entire_shape=tensor.shape,
dim_partition_dict=dim_partition_dict)
return sharding_spec
def _generate_resharding_costs(self, sharding_spec_for_input):
'''
Compute the resharding costs with this specific strategy.
Note: The resharding_cost of weight is NOT counted.
Argument:
resharding_costs(Dict[int, List[float]]): The resharding cost generated in this method will be appended into this dictionary.
Resharding_cost[i][j] means the cost of i-th argument in the output node argument list
with j-th strategy in its strategies_vector transforms to sharding spec wanted in this
strategy.
sharding_spec_for_input(ShardingSpec): ShardingSpec of the input node.
'''
# The resharding_cost of weight is counted due to sharing weight cases.
resharding_costs = {}
for input_node, input_spec in zip(self.predecessor_node, sharding_spec_for_input):
resharding_costs[input_node] = []
for strategy in input_node.strategies_vector:
input_sharding_spec = strategy.output_sharding_spec
assert isinstance(input_sharding_spec, ShardingSpec), f'The input node should NOT be a tuple of tensor.'
_, _, resharding_cost = self.shape_consistency_manager.shape_consistency(
input_sharding_spec, input_spec)
resharding_costs[input_node].append(resharding_cost)
return resharding_costs