ColossalAI/colossalai/auto_parallel/solver/dot_handler.py

240 lines
12 KiB
Python

import operator
import torch
from colossalai.auto_parallel.solver.sharding_strategy import ShardingStrategy, StrategiesVector
from .operator_handler import OperatorHandler
from functools import reduce
__all__ = ['DotHandler']
class DotHandler(OperatorHandler):
"""
A OperatorHandler which deals with the sharding strategies of linear matrix multiplication.
"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.input_data = self.predecessor_node[0]._meta_data
self.weight = self.module_named_parameters['weight']
self.output_data = self.node._meta_data
def _generate_compute_cost(self, input_shape, weight_shape):
# TODO: consider bias addition
compute_cost = reduce(operator.mul, input_shape) * weight_shape[0] * 2
return compute_cost
def split_lhs_space_rhs_space(self, mesh_dim_0, mesh_dim_1):
# handle case SS = SR x RS
name = f'S{mesh_dim_0}S{mesh_dim_1} = S{mesh_dim_0}R x RS{mesh_dim_1}'
dim_partition_dict_for_input = {0: [mesh_dim_0]}
sharding_spec_for_input = self._generate_sharding_spec(self.input_data, dim_partition_dict_for_input)
# linear layer weight is transposed during init
dim_partition_dict_for_weight = {0: [mesh_dim_1]}
sharding_spec_for_weight = self._generate_sharding_spec(self.weight, dim_partition_dict_for_weight)
dim_partition_dict_for_output = {0: [mesh_dim_0], 1: [mesh_dim_1]}
sharding_spec_for_ouput = self._generate_sharding_spec(self.output_data, dim_partition_dict_for_input)
# generate resharding cost for this strategy
resharding_costs = self._generate_resharding_costs([sharding_spec_for_input])
# compute computation cost
compute_cost = self._generate_compute_cost(self.input_data.shape, self.weight.shape)
# compute the memory cost of this strategy
dtype = self.input_data.dtype
numel = self.output_data.numel()
size_per_elem_bytes = torch.tensor([], dtype=dtype).element_size()
sharding_size = self.device_mesh.shape[mesh_dim_0] * self.device_mesh.shape[mesh_dim_1]
memory_cost = numel * size_per_elem_bytes / sharding_size
# compute the communication cost
# no all-reduce required for this case
communication_cost = 0
# create and register strategy
sharding_strategies = ShardingStrategy(name,
output_sharding_spec=sharding_spec_for_ouput,
compute_cost=compute_cost,
communication_cost=communication_cost,
memory_cost=memory_cost,
resharding_costs=resharding_costs,
input_shardings=(sharding_spec_for_input, sharding_spec_for_weight))
self.strategies_vector.append(sharding_strategies)
def split_lhs_space_both_contract(self, mesh_dim_0, mesh_dim_1):
# handle the case SR = SS x SR
name = f'S{mesh_dim_0}R = S{mesh_dim_0}S{mesh_dim_1} x S{mesh_dim_1}R'
dim_partition_dict_for_input = {0: [mesh_dim_0], 1: [mesh_dim_1]}
sharding_spec_for_input = self._generate_sharding_spec(self.input_data, dim_partition_dict_for_input)
# since weight of the linear layer is transposed
# the actual dim to be sharded is 1
dim_partition_dict_for_weight = {1: [mesh_dim_0]}
sharding_spec_for_weight = self._generate_sharding_spec(self.weight, dim_partition_dict_for_weight)
dim_partition_dict_for_output = {0: [mesh_dim_0]}
sharding_spec_for_ouput = self._generate_sharding_spec(self.output_data, dim_partition_dict_for_output)
# generate resharding cost for this strategy
resharding_costs = self._generate_resharding_costs([sharding_spec_for_input])
# compute the computation cost of this strategy
compute_cost = self._generate_compute_cost(self.input_data.shape, self.weight.shape)
# compute the memory cost of this strategy
dtype = self.input_data.dtype
numel = self.output_data.numel()
size_per_elem_bytes = torch.tensor([], dtype=dtype).element_size()
sharding_size = self.device_mesh.shape[mesh_dim_0]
memory_cost = numel * size_per_elem_bytes / sharding_size
# compute the communication cost of this strategy
communication_cost = self.device_mesh.all_reduce_cost(memory_cost, mesh_dim_1)
sharding_strategies = ShardingStrategy(name,
output_sharding_spec=sharding_spec_for_ouput,
compute_cost=compute_cost,
communication_cost=communication_cost,
memory_cost=memory_cost,
resharding_costs=resharding_costs,
input_shardings=(sharding_spec_for_input, sharding_spec_for_weight))
self.strategies_vector.append(sharding_strategies)
def split_rhs_space_both_contract(self, mesh_dim_0, mesh_dim_1):
name = f'RS{mesh_dim_1} = RS{mesh_dim_0} x S{mesh_dim_0}S{mesh_dim_1}'
dim_partition_dict_for_input = {1: [mesh_dim_0]}
sharding_spec_for_input = self._generate_sharding_spec(self.input_data, dim_partition_dict_for_input)
dim_partition_dict_for_weight = {0: [mesh_dim_0], 1: [mesh_dim_1]}
sharding_spec_for_weight = self._generate_sharding_spec(self.weight, dim_partition_dict_for_weight)
dim_partition_dict_for_output = {1: [mesh_dim_1]}
sharding_spec_for_ouput = self._generate_sharding_spec(self.output_data, dim_partition_dict_for_input)
# generate resharding cost for this strategy
resharding_costs = self._generate_resharding_costs([sharding_spec_for_input])
# compute the computation cost of this strategy
compute_cost = self._generate_compute_cost(self.input_data.shape, self.weight.shape)
# compute the memory cost of this strategy
dtype = self.input_data.dtype
numel = self.output_data.numel()
size_per_elem_bytes = torch.tensor([], dtype=dtype).element_size()
sharding_size = self.device_mesh.shape[mesh_dim_0]
memory_cost = numel * size_per_elem_bytes / sharding_size
# compute the communication cost of this strategy
communication_cost = self.device_mesh.all_reduce_cost(memory_cost, mesh_dim_1)
sharding_strategies = ShardingStrategy(name,
output_sharding_spec=sharding_spec_for_ouput,
compute_cost=compute_cost,
communication_cost=communication_cost,
memory_cost=memory_cost,
resharding_costs=resharding_costs,
input_shardings=(sharding_spec_for_input, sharding_spec_for_weight))
self.strategies_vector.append(sharding_strategies)
def recompute_split_both_contract(self, mesh_dim):
name = f'RR = RS{mesh_dim} x S{mesh_dim}R'
dim_partition_dict_for_input = {1: [mesh_dim]}
sharding_spec_for_input = self._generate_sharding_spec(self.input_data, dim_partition_dict_for_input)
dim_partition_dict_for_weight = {1: [mesh_dim]}
sharding_spec_for_weight = self._generate_sharding_spec(self.weight, dim_partition_dict_for_weight)
dim_partition_dict_for_output = {}
sharding_spec_for_ouput = self._generate_sharding_spec(self.output_data, dim_partition_dict_for_output)
# generate resharding cost for this strategy
resharding_costs = self._generate_resharding_costs([sharding_spec_for_input])
# compute the computation cost of this strategy
compute_cost = self._generate_compute_cost(self.input_data.shape, self.weight.shape)
# compute the memory cost of this strategy
dtype = self.input_data.dtype
numel = self.output_data.numel()
size_per_elem_bytes = torch.tensor([], dtype=dtype).element_size()
memory_cost = numel * size_per_elem_bytes
# compute the communication cost of this strategy
communication_cost = self.device_mesh.all_reduce_cost(memory_cost, mesh_dim)
sharding_strategies = ShardingStrategy(name,
output_sharding_spec=sharding_spec_for_ouput,
compute_cost=compute_cost,
communication_cost=communication_cost,
memory_cost=memory_cost,
resharding_costs=resharding_costs,
input_shardings=(sharding_spec_for_input, sharding_spec_for_weight))
self.strategies_vector.append(sharding_strategies)
def split_rhs_space_only(self, mesh_dim):
name = f'RS{mesh_dim} = RR x RS{mesh_dim}'
dim_partition_dict_for_input = {}
sharding_spec_for_input = self._generate_sharding_spec(self.input_data, dim_partition_dict_for_input)
dim_partition_dict_for_weight = {0: [mesh_dim]}
sharding_spec_for_weight = self._generate_sharding_spec(self.weight, dim_partition_dict_for_weight)
dim_partition_dict_for_output = {1: [mesh_dim]}
sharding_spec_for_ouput = self._generate_sharding_spec(self.output_data, dim_partition_dict_for_output)
# generate resharding cost for this strategy
resharding_costs = self._generate_resharding_costs([sharding_spec_for_input])
# compute the computation cost of this strategy
compute_cost = self._generate_compute_cost(self.input_data.shape, self.weight.shape)
# compute the memory cost of this strategy
dtype = self.input_data.dtype
numel = self.output_data.numel()
size_per_elem_bytes = torch.tensor([], dtype=dtype).element_size()
sharding_size = self.device_mesh.shape[mesh_dim]
memory_cost = numel * size_per_elem_bytes / sharding_size
# compute the communication cost of this strategy
communication_cost = self.device_mesh.all_reduce_cost(memory_cost, mesh_dim)
sharding_strategies = ShardingStrategy(name,
output_sharding_spec=sharding_spec_for_ouput,
compute_cost=compute_cost,
communication_cost=communication_cost,
memory_cost=memory_cost,
resharding_costs=resharding_costs,
input_shardings=(sharding_spec_for_input, sharding_spec_for_weight))
self.strategies_vector.append(sharding_strategies)
def register_strategy(self) -> StrategiesVector:
'''
Generate every possible strategies for a Conv node, and record all strategies into the strategies_vector.
Output:
'''
# SS = SR x RS
self.split_lhs_space_rhs_space(0, 1)
self.split_lhs_space_rhs_space(1, 0)
# SR = SS x SR
self.split_lhs_space_both_contract(0, 1)
self.split_lhs_space_both_contract(1, 0)
# RS = RS x SS
self.split_rhs_space_both_contract(0, 1)
self.split_rhs_space_both_contract(1, 0)
# RR= RS x SR
self.recompute_split_both_contract(0)
self.recompute_split_both_contract(1)
# RS = RR x RS
self.split_rhs_space_only(0)
self.split_rhs_space_only(1)
return self.strategies_vector