ai-content-maker/.venv/Lib/site-packages/torch/_dynamo/compiled_autograd.py

281 lines
9.5 KiB
Python

import contextlib
import functools
from typing import List, Optional
import torch
from torch._dynamo.external_utils import call_backward, call_hook
from torch._dynamo.source import GetItemSource, LocalSource
from torch._dynamo.utils import counters, lazy_format_graph_code
from torch._logging import getArtifactLogger, trace_structured
from torch._prims_common import clone_preserve_strides
from torch._subclasses import FakeTensorMode
from torch.fx import GraphModule
from torch.fx.experimental._backward_state import BackwardState
from torch.fx.experimental.proxy_tensor import (
decompose,
disable_autocast_cache,
disable_proxy_modes_tracing,
fetch_object_proxy,
ProxyTorchDispatchMode,
PythonKeyTracer,
track_tensor_tree,
)
from torch.fx.experimental.symbolic_shapes import DimDynamic, ShapeEnv
from torch.fx.proxy import Proxy
compiled_autograd_log = getArtifactLogger(__name__, "compiled_autograd")
def maybe_clone(x):
if x is not None:
return clone_preserve_strides(x)
return x
class AutogradCompilerInstance:
def __init__(self, compiler_fn) -> None:
self.compiler_fn = compiler_fn
self.stack = contextlib.ExitStack()
self.close = self.stack.close
self.shape_env = ShapeEnv()
self.fake_tensor_mode = FakeTensorMode(
allow_fallback_kernels=True,
allow_non_fake_inputs=True,
shape_env=self.shape_env,
)
self.fx_tracer = PythonKeyTracer()
self.proxy_mode = ProxyTorchDispatchMode(self.fx_tracer, "symbolic")
self.hooks_proxy: Optional[Proxy] = None
def wrap_fake(self, x, source):
assert isinstance(x, torch.Tensor)
return self.fake_tensor_mode.from_tensor(x, source=source)
@staticmethod
def source(name, idx) -> GetItemSource:
return GetItemSource(LocalSource(name), idx)
def begin_capture(self, inputs: List[torch.Tensor], sizes: List[int]):
counters["compiled_autograd"]["captures"] += 1
self.fx_tracer.root = torch.nn.Module()
self.fx_tracer.graph = torch.fx.Graph(tracer_cls=PythonKeyTracer)
self.fx_tracer.tensor_attrs = {}
args_proxy = self.fx_tracer.create_proxy("placeholder", "inputs", (), {})
sizes_proxy = self.fx_tracer.create_proxy("placeholder", "sizes", (), {})
self.hooks_proxy = self.fx_tracer.create_proxy("placeholder", "hooks", (), {})
# tensor inputs to fake tensors
inputs = [
self.wrap_fake(x, self.source("inputs", idx))
for idx, x in enumerate(inputs)
]
proxies = [args_proxy[i] for i in range(len(inputs))]
self.bind_tensors_to_proxies(inputs, proxies)
# size inputs to symints
sizes = [
self.shape_env.create_unspecified_symint_and_symbol(
val,
self.source("sizes", idx),
DimDynamic.DYNAMIC,
)
for idx, val in enumerate(sizes)
]
self.bind_tensors_to_proxies(sizes, sizes_proxy)
# TODO(jansel): are all these modes needed?
self.stack.enter_context(decompose({}))
self.stack.enter_context(self.fake_tensor_mode)
self.stack.enter_context(self.proxy_mode.sym_mode)
self.stack.enter_context(self.proxy_mode)
self.stack.enter_context(disable_autocast_cache())
return inputs, sizes
def proxy_call_backward(
self,
inputs,
output_metadatas,
saved_tensors,
backward_idx: int,
):
assert self.hooks_proxy is not None
backward_fn = self.hooks_proxy[backward_idx] # type: ignore[index]
proxies = self.fx_tracer.create_proxy(
kind="call_function",
target=call_backward,
args=(
backward_fn,
self.to_proxy(saved_tensors),
*self.to_proxy(inputs),
),
kwargs={},
)
with disable_proxy_modes_tracing():
# create fake Tensors
grad_ins: List[Optional[torch.Tensor]] = []
for output_metadata in output_metadatas:
if output_metadata is None:
grad_ins.append(None)
continue
layout, device, dtype, size = output_metadata
grad_ins.append(
torch.empty(size=size, dtype=dtype, layout=layout, device=device)
)
self.bind_tensors_to_proxies(grad_ins, proxies)
return tuple(grad_ins)
def proxy_call_hook(self, hook, *args):
return self.fx_tracer.create_proxy(
"call_function",
call_hook,
(
hook,
*[self.to_proxy(x) for x in args],
),
{},
)
def tensor_pre_hook(self, inputs, hook_id, i: int):
assert self.hooks_proxy is not None
hook = self.hooks_proxy[hook_id] # type: ignore[index]
proxy = self.proxy_call_hook(
hook,
inputs[i],
)
with disable_proxy_modes_tracing():
inputs[i] = maybe_clone(inputs[i])
self.bind_tensors_to_proxies([inputs[i]], [proxy])
return inputs
def pre_hook(self, inputs, hook_id):
assert self.hooks_proxy is not None
hook = self.hooks_proxy[hook_id] # type: ignore[index]
proxies = self.proxy_call_hook(
hook,
inputs,
)
with disable_proxy_modes_tracing():
inputs = [maybe_clone(x) for x in inputs]
self.bind_tensors_to_proxies(inputs, proxies)
return inputs
def post_hook(self, outputs, inputs, hook_id):
assert self.hooks_proxy is not None
hook = self.hooks_proxy[hook_id] # type: ignore[index]
proxies = self.proxy_call_hook(
hook,
outputs,
inputs,
)
with disable_proxy_modes_tracing():
outputs = [maybe_clone(x) for x in outputs]
self.bind_tensors_to_proxies(outputs, proxies)
return outputs
def post_acc_grad_hook(self, input, hook_id):
assert isinstance(input, torch.Tensor)
assert self.hooks_proxy is not None
hook = self.hooks_proxy[hook_id] # type: ignore[index]
proxies = self.proxy_call_hook(
hook,
input,
)
with disable_proxy_modes_tracing():
input = [maybe_clone(input)]
self.bind_tensors_to_proxies(input, proxies)
return input
def end_capture(self, outputs):
self.stack.close()
self.fx_tracer.create_node(
"output",
"output",
(self.fx_tracer.create_arg(self.to_proxy(outputs)),),
{},
)
graph = GraphModule(
self.fx_tracer.root, self.fx_tracer.graph, "CompiledAutograd"
)
compiled_autograd_log.info(
"%s", lazy_format_graph_code("Compiled autograd graph", graph)
)
trace_structured(
"compiled_autograd_graph",
payload_fn=lambda: graph.print_readable(print_output=False),
)
return self.compiler_fn(graph)
def to_proxy(self, t):
if t is None:
return None
if isinstance(t, list):
return [self.to_proxy(x) for x in t]
if isinstance(t, tuple):
return tuple(self.to_proxy(x) for x in t)
assert isinstance(t, (torch.Tensor, torch.SymInt))
return fetch_object_proxy(self.fx_tracer)(t).proxy
def bind_tensors_to_proxies(self, tensors, proxies):
if isinstance(proxies, torch.fx.Proxy):
proxies = [proxies[i] for i in range(len(tensors))]
assert len(tensors) == len(proxies)
track_tensor_tree(tensors, proxies, constant=None, tracer=self.fx_tracer)
def bind_backward_state(self, index: int):
assert self.hooks_proxy is not None
proxy = self.hooks_proxy[index] # type: ignore[index]
bw_state = BackwardState()
track_tensor_tree(bw_state, proxy, constant=None, tracer=self.fx_tracer)
return bw_state
compiled_autograd_enabled = False
# We may have code like:
# with enable(compiler_fn):
# ...
# with disable():
# ...
# ...
# The disable() call just want to disable compiled autograd temporarily.
# But overall the feature is enabled.
#
# The code covered by the disable context manager has no way to know if
# compiled autograd is overall eanbled. Use another variable
# compiled_autograd_enabled_count to indicate how many times compiled
# autograd has been enabled in the call stack for this purpose.
compiled_autograd_enabled_count = 0
@contextlib.contextmanager
def enable(compiler_fn):
prior = torch._C._dynamo.compiled_autograd.set_autograd_compiler(
functools.partial(AutogradCompilerInstance, compiler_fn)
)
global compiled_autograd_enabled, compiled_autograd_enabled_count
compiled_autograd_enabled = True
compiled_autograd_enabled_count += 1
try:
with torch.autograd.set_multithreading_enabled(False):
yield
finally:
compiled_autograd_enabled_count -= 1
if not prior:
compiled_autograd_enabled = False
torch._C._dynamo.compiled_autograd.set_autograd_compiler(prior)
@contextlib.contextmanager
def disable():
prior = torch._C._dynamo.compiled_autograd.set_autograd_compiler(None)
global compiled_autograd_enabled
compiled_autograd_enabled = False
try:
yield
finally:
if prior:
compiled_autograd_enabled = True
torch._C._dynamo.compiled_autograd.set_autograd_compiler(prior)