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ColossalAI/colossalai/fx/profiler/shard_utils.py

115 lines
4.1 KiB

import torch
from torch.fx import Node
from .._compatibility import compatibility, is_compatible_with_meta
from .memory_utils import activation_size
if is_compatible_with_meta():
from .constants import OUTPUT_SAVED_MOD, OUTPUT_SAVED_OPS
__all__ = ["calculate_fwd_in", "calculate_fwd_tmp", "calculate_fwd_out"]
@compatibility(is_backward_compatible=False)
def calculate_fwd_in(n: Node) -> int:
"""A helper function to calculate `fwd_in` (with sharding spec)
Args:
n (Node): a node from the graph
Returns:
fwd_in (int): the result of `fwd_in`
"""
# TODO(super-dainiu): should divide the memory by sharding spec
return activation_size(n.meta["fwd_in"])
@compatibility(is_backward_compatible=False)
def calculate_fwd_tmp(n: Node) -> int:
"""A helper function to calculate `fwd_tmp` (with sharding spec)
Currently, `torch.nn.ReLU` behaves weirdly, so we have to patch it for accuracy.
Args:
n (Node): a node from the graph
Returns:
fwd_tmp (int): the result of `fwd_tmp`
"""
# TODO(super-dainiu): should divide the memory by sharding spec
def is_relu_like_node(n: Node) -> bool:
"""Check if a node is a ReLU-like node.
ReLU-like nodes have the following properties:
- They are either `call_function` or `call_module`
- Their output tensors are directly saved for backward
- Their input tensors are not saved for backward
An example is `torch.nn.functional.softmax` which has (forward + backward):
def forward(self, input_2):
_softmax_default = torch.ops.aten._softmax.default(input_2, None, None); input_2 = None
zeros_like_default = torch.ops.aten.zeros_like.default(_softmax_default, dtype = None, layout = None, device = None, pin_memory = None)
detach_default = torch.ops.aten.detach.default(_softmax_default); _softmax_default = None
_softmax_backward_data_default = torch.ops.aten._softmax_backward_data.default(zeros_like_default, detach_default, None, None); zeros_like_default = detach_default = None
detach_default_1 = torch.ops.aten.detach.default(_softmax_backward_data_default); _softmax_backward_data_default = None
detach_default_2 = torch.ops.aten.detach.default(detach_default_1); detach_default_1 = None
Args:
n (Node): A node from the graph
Returns:
bool: Whether the node is a ReLU-like node
"""
if n.op == 'call_function':
return n.target in OUTPUT_SAVED_OPS
elif n.op == 'call_module':
return type(n.graph.owning_module.get_submodule(n.target)) in OUTPUT_SAVED_MOD
return False
if not is_relu_like_node(n):
return activation_size(n.meta["fwd_tmp"])
return 0
@compatibility(is_backward_compatible=False)
def calculate_fwd_out(n: Node) -> int:
"""A helper function to calculate `fwd_out` (with sharding spec)
Args:
n (Node): a node from the graph
Returns:
fwd_out (int): the result of `fwd_out`
"""
# TODO(super-dainiu): should divide the memory by sharding spec
def intersect(a, b):
return {k: a[k] for k in a if k in b}
fwd_in = dict()
for u in n.users:
fwd_in.update({x.data_ptr(): x for x in u.meta["fwd_in"] if isinstance(x, torch.Tensor)})
fwd_out = {x.data_ptr(): x for x in n.meta["fwd_out"] if isinstance(x, torch.Tensor)}
return activation_size(intersect(fwd_in, fwd_out))
def calculate_fwd_time(n: Node) -> float:
"""A helper function to calculate `fwd_time` (with sharding spec)
Args:
n (Node): a node from the graph
Returns:
fwd_time (float): the result of `fwd_time`
"""
# TODO(super-dainiu): should divide the time by the number of GPUs as well as TFLOPs
return n.meta["fwd_time"]
def calculate_bwd_time(n: Node) -> float:
"""A helper function to calculate `bwd_time` (with sharding spec)
Args:
n (Node): a node from the graph
Returns:
bwd_time (float): the result of `bwd_time`
"""
# TODO(super-dainiu): should divide the time by the number of GPUs as well as TFLOPs
return n.meta["bwd_time"]