Files
pytorch/torch/_compile.py
zhxchen17 38c4d05535 [precompile] Ensure @disable()-ed function won't trigger recompile from precompile bytecode. (#155363)
In a precompiled bytecode, it looks like the following:
```
pre-graph bytecode
...
compiled graph code
...
post-graph bytecode
```

In pre-graph bytecode we have calls into helper functions like torch._dynamo.utils.call_size which will invoke @disable inside the bytecode.

Normally torch.compile() will handle these frames fine, but for precompile we will load bytecode from a clean state of dynamo and we want a way to assert recompile never happen, so the current way to ensure this is by doing set_stance("fail_on_recompile") (open to any other idea to test this, but IMO this is the closest thing we have today).

This approach doesn't work when util functions like call_size() is involved and this PR fixes a bunch of places to make sure "fail_on_recompile" can skip through the functions meant to be skipped during compilation.

Differential Revision: [D76156867](https://our.internmc.facebook.com/intern/diff/D76156867/)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/155363
Approved by: https://github.com/jamesjwu, https://github.com/jansel
ghstack dependencies: #155329
2025-06-10 16:13:38 +00:00

60 lines
2.0 KiB
Python

"""
APIs related to torch.compile which lazily import torch._dynamo to avoid
circular dependencies.
"""
import functools
from typing import Callable, Literal, Optional, overload, TypeVar, Union
from typing_extensions import ParamSpec
_T = TypeVar("_T")
_P = ParamSpec("_P")
@overload
def _disable_dynamo(
fn: Callable[_P, _T], recursive: bool = True
) -> Callable[_P, _T]: ...
@overload
def _disable_dynamo(
fn: Literal[None] = None, recursive: bool = True
) -> Callable[[Callable[_P, _T]], Callable[_P, _T]]: ...
def _disable_dynamo(
fn: Optional[Callable[_P, _T]] = None, recursive: bool = True
) -> Union[Callable[_P, _T], Callable[[Callable[_P, _T]], Callable[_P, _T]]]:
"""
This API should be only used inside torch, external users should still use
torch._dynamo.disable. The main goal of this API is to avoid circular
imports issues that is common while using _dynamo.disable inside torch
itself.
This API avoids it by lazily importing torch._dynamo from the import time to
the invocation of the decorated function.
"""
if fn is not None:
@functools.wraps(fn)
def inner(*args: _P.args, **kwargs: _P.kwargs) -> _T:
# cache this on the first invocation to avoid adding too much overhead.
disable_fn = getattr(fn, "__dynamo_disable", None)
if disable_fn is None:
import torch._dynamo
# We can safely turn off functools.wraps here because the inner
# already wraps fn in the outer scope.
disable_fn = torch._dynamo.disable(fn, recursive, wrapping=False)
fn.__dynamo_disable = disable_fn # type: ignore[attr-defined]
return disable_fn(*args, **kwargs)
return inner
else:
# decorator usage like @_disable_dynamo(recursive=False). The resulting
# object expects the original decorated function as the arg.
return functools.partial(_disable_dynamo, recursive=recursive)