ColossalAI/colossalai/fx/passes/shard_1d_pass.py

60 lines
2.2 KiB
Python

import torch
from colossalai.tensor import ColoTensorSpec, distspec, ProcessGroup, ComputeSpec, ComputePattern, ShardSpec
def weight_split(weight: torch.Tensor, dim: int) -> torch.nn.parameter.Parameter:
"""weight_split
split a nn.Parameter
Args:
weight (torch.nn.parameter.Parameter): a torch Parameter instance
dim (int): the dimension to be sharded along with
Returns:
_type_: _description_
"""
# Append a Tensor spec to target_module.weight.shard
# Convert to ColoTensor: colo_tensor = ColoTensor.from_torch_tensor(tensor, spec)
assert isinstance(weight, torch.Tensor), \
f'The type of the input tensor should be torch.nn.parameter' \
f'Your Input tensor is {type(weight)}'
# FIXME() I initialized a PG for this tensor. Only has TP comm group.
# we only consider the TP-only caes.
world_size = torch.distributed.get_world_size()
pg = ProcessGroup(tp_degree=world_size)
spec = ColoTensorSpec(pg, ShardSpec([dim], [pg.tp_world_size()]), ComputeSpec(ComputePattern.TP1D))
# As you has constructed a Spec, why not directly convert the tensor to ColoTensor.
setattr(weight, "fx_attr", spec)
return weight
def column_shard_linear_pass(gm: torch.fx.GraphModule):
mod_graph = gm.graph
for node in mod_graph.nodes:
if node.op == "call_module":
target_module = node.graph.owning_module.get_submodule(node.target)
if isinstance(target_module, torch.nn.Linear):
target_module.weight = weight_split(target_module.weight, dim=0)
if target_module.bias is not None:
target_module.bias.data = weight_split(target_module.bias.data, dim=0)
gm.recompile()
return gm
def row_shard_linear_pass(gm: torch.fx.GraphModule):
mod_graph = gm.graph
for node in mod_graph.nodes:
if node.op == "call_module":
target_module = node.graph.owning_module.get_submodule(node.target)
if isinstance(target_module, torch.nn.Linear):
target_module.weight = weight_split(target_module.weight, dim=-1)
gm.recompile()
return gm
#TODO: add elementwise op process pass, then we can try to use column and row mixed strategy.