pytorch/torch/_dynamo/side_effects.py
Animesh Jain 1a0b247762 [dynamo] Bug fix for LOAD_GLOBAL and STORE_GLOBAL (#125002)
Earlier globals of inlined functions from other files were not handled correctly. We were not tracking mutations on them. They were colliding with the same global name in the parent function etc. This PR overrides the LOAD/STORE_GLOBAL for inline tx and tracks mutation on them separately.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125002
Approved by: https://github.com/jansel
ghstack dependencies: #125097, #125107
2024-04-28 15:24:17 +00:00

545 lines
22 KiB
Python

import inspect
import warnings
from typing import Any, Dict, List, Optional, Union
import torch.nn
from . import utils, variables
from .bytecode_transformation import (
create_call_function,
create_call_method,
create_instruction,
create_load_method,
)
from .codegen import PyCodegen
from .exc import unimplemented
from .source import GlobalSource, LocalSource, Source
from .utils import nn_module_new, object_new
from .variables.base import (
is_side_effect_safe,
MutableLocalBase,
MutableLocalSource,
VariableTracker,
)
class MutableSideEffects(MutableLocalBase):
"""
VariableTracker.mutable_local marker to indicate a list passed as
an input that if we mutate we need to re-apply those mutations after
the graph runs.
"""
def __init__(self, source: Source, is_modified: bool = False):
super().__init__(MutableLocalSource.Existing)
self.source = source
self.is_modified = is_modified
class AttributeMutation(MutableLocalBase):
"""
VariableTracker.mutable_local marker to track changes to attributes
"""
def __init__(self, typ: MutableLocalSource, source: Optional[Source]):
super().__init__(typ)
self.source = source
class AttributeMutationExisting(AttributeMutation):
def __init__(self, source: Source):
super().__init__(MutableLocalSource.Existing, source)
self.source = source
class AttributeMutationNew(AttributeMutation):
def __init__(self, source: Optional[Source], cls_source: Optional[Source]):
super().__init__(MutableLocalSource.Local, source)
self.cls_source = cls_source
class SideEffects:
"""
Track side effects (list mutation, setattr, etc) that need to be
applied after an FX graph is run.
"""
id_to_variable: Dict[int, VariableTracker]
store_attr_mutations: Dict[MutableLocalBase, Dict[str, VariableTracker]]
keepalive: List[Any]
def __init__(
self,
id_to_variable=None,
store_attr_mutations=None,
keepalive=None,
save_for_backward=None,
tensor_hooks=None,
):
super().__init__()
self.id_to_variable = id_to_variable or {}
self.store_attr_mutations = store_attr_mutations or {}
self.keepalive = keepalive or []
self.save_for_backward = save_for_backward or []
self.tensor_hooks = tensor_hooks or {}
def __eq__(self, other: object) -> bool:
assert isinstance(other, SideEffects)
# NB: do NOT test keepalive
return (
self.id_to_variable == other.id_to_variable
and self.store_attr_mutations == other.store_attr_mutations
and self.save_for_backward == other.save_for_backward
and self.tensor_hooks == other.tensor_hooks
)
def diff(self, other: "SideEffects") -> Optional[str]:
if self.id_to_variable != other.id_to_variable:
sk_itv = self.id_to_variable.keys()
ok_itv = other.id_to_variable.keys()
if sk_itv != ok_itv:
return f"id_to_variable keys: {sk_itv} != {ok_itv}"
# Feel free to augment this with more fancy diffing logic
# if needed for debugging
return "id_to_variable: unknown diff"
elif self.store_attr_mutations != other.store_attr_mutations:
sk_sam = self.store_attr_mutations.keys()
ok_sam = other.store_attr_mutations.keys()
if sk_sam != ok_sam:
return f"store_attr_mutations keys: {sk_sam} != {ok_sam}"
return "store_attr_mutations: unknown diff"
elif self.save_for_backward != other.save_for_backward:
return "save_for_backward"
elif self.tensor_hooks != other.tensor_hooks:
return "tensor_hooks"
else:
return None
def clone(self):
"""Create a shallow copy"""
return self.__class__(
id_to_variable=dict(self.id_to_variable),
store_attr_mutations={
k: dict(v) for k, v in self.store_attr_mutations.items()
},
keepalive=list(self.keepalive),
save_for_backward=self.save_for_backward,
tensor_hooks=self.tensor_hooks,
)
def __contains__(self, item):
return id(item) in self.id_to_variable
def __getitem__(self, item):
return self.id_to_variable[id(item)]
def check_allowed_side_effect(self, item):
from torch._dynamo.variables.misc import AutogradFunctionContextVariable
# People do things like self.dim = dim inside autograd.Function.
# These are benign.
if isinstance(item, AutogradFunctionContextVariable):
return True
if not is_side_effect_safe(item.mutable_local):
unimplemented(
"HigherOrderOperator: Mutating a variable not in the current scope (SideEffects)"
)
def store_attr(self, item: VariableTracker, name: str, value: VariableTracker):
assert self.is_attribute_mutation(item)
self.check_allowed_side_effect(item)
if item.mutable_local not in self.store_attr_mutations:
self.store_attr_mutations[item.mutable_local] = {}
self.store_attr_mutations[item.mutable_local][name] = value
def load_attr(self, item, name, deleted_ok=False):
assert self.is_attribute_mutation(item)
result = self.store_attr_mutations[item.mutable_local][name]
if not deleted_ok and isinstance(result, variables.DeletedVariable):
unimplemented("read deleted attribute")
return result
def store_cell(self, cellvar, value):
assert isinstance(cellvar, variables.NewCellVariable)
assert isinstance(value, variables.VariableTracker)
self.store_attr(cellvar, "cell_contents", value)
def load_cell(self, cellvar):
assert isinstance(cellvar, variables.NewCellVariable)
return self.load_attr(cellvar, "cell_contents")
def load_global(self, gvar: VariableTracker, name: str):
assert isinstance(gvar, variables.VariableTracker)
return self.load_attr(gvar, name)
def store_global(self, gvar: VariableTracker, name: str, value: VariableTracker):
assert isinstance(gvar, variables.VariableTracker)
assert isinstance(value, variables.VariableTracker)
self.store_attr(gvar, name, value)
@staticmethod
def cls_supports_mutation_side_effects(cls):
return (
inspect.getattr_static(cls, "__getattribute__", None)
is object.__getattribute__
)
def is_attribute_mutation(self, item):
return isinstance(item.mutable_local, AttributeMutation)
def has_pending_mutation(self, item):
return self.is_attribute_mutation(item) and bool(
self.store_attr_mutations.get(item.mutable_local)
)
def has_pending_mutation_of_attr(self, item, name):
return self.is_attribute_mutation(
item
) and name in self.store_attr_mutations.get(item.mutable_local, ())
def is_modified(self, item):
if isinstance(item.mutable_local, AttributeMutationNew):
return True
if self.is_attribute_mutation(item):
return item.mutable_local in self.store_attr_mutations
return item.mutable_local.is_modified
def _track_obj(
self,
item: Any,
variable: VariableTracker,
mutable_cls=MutableSideEffects,
):
"""Start tracking a new variable for mutation"""
assert variable.source is not None
variable.mutable_local = mutable_cls(variable.source)
self.id_to_variable[id(item)] = variable
self.keepalive.append(item)
return variable
track_mutable = _track_obj
def track_object_existing(
self,
item: Any,
variable: VariableTracker,
):
return self._track_obj(item, variable, mutable_cls=AttributeMutationExisting)
def track_object_new(
self,
cls_source: Source,
user_cls: Any,
variable_cls: Any,
options,
):
if user_cls is torch.autograd.function.FunctionCtx:
with warnings.catch_warnings(record=True):
obj = torch.autograd.Function()
elif issubclass(user_cls, torch.nn.Module):
obj = nn_module_new(user_cls)
else:
obj = object_new(user_cls)
variable = variable_cls(
obj,
mutable_local=AttributeMutationNew(None, cls_source),
**options,
)
self.id_to_variable[id(obj)] = variable
self.keepalive.append(obj)
return variable
def track_cell_new(
self,
):
obj = object()
variable = variables.NewCellVariable(
mutable_local=AttributeMutationNew(None, None),
)
self.id_to_variable[id(obj)] = variable
self.keepalive.append(obj)
return variable
def track_cell_existing(self, source: Source, item: Any):
variable = variables.NewCellVariable(
mutable_local=AttributeMutationExisting(source),
)
self.id_to_variable[id(item)] = variable
self.keepalive.append(item)
return variable
def track_global_existing(self, source: Source, item: Any):
variable = variables.NewGlobalVariable(
mutable_local=AttributeMutationExisting(source),
)
self.id_to_variable[id(item)] = variable
self.keepalive.append(item)
return variable
def track_save_for_backward(self, ctx, args):
assert isinstance(ctx, variables.AutogradFunctionContextVariable)
self.save_for_backward.append((ctx, args))
def track_tensor_variables_from_runahead_side_effects(self, other):
# In higher order ops we want to keep track of tensors seen in the
# speculate_subgraph so that we don't lift them again as a new input in
# other speculate_subgraph or in the root tracer.
for other_item in other.keepalive:
other_id = id(other_item)
other_variable = other.id_to_variable[other_id]
if other_id not in self.id_to_variable and isinstance(
other_variable, variables.TensorVariable
):
self.track_object_existing(other_item, other_variable)
def prune_dead_object_new(self, tx):
live_new_objects = set()
skip_obj = None
def visit(var: VariableTracker):
if (
isinstance(var.mutable_local, AttributeMutationNew)
and var.mutable_local is not skip_obj
):
live_new_objects.add(var.mutable_local)
def is_live(var: Union[MutableLocalBase, VariableTracker]):
if isinstance(var, AttributeMutationNew):
return var in live_new_objects
if isinstance(var, VariableTracker):
return is_live(var.mutable_local)
return True
VariableTracker.visit(visit, (tx.stack, tx.symbolic_locals))
for var in self.id_to_variable.values():
if not isinstance(var.mutable_local, AttributeMutationNew):
VariableTracker.visit(visit, var)
for skip_obj, setattrs in self.store_attr_mutations.items():
VariableTracker.visit(visit, setattrs)
self.id_to_variable = {
k: v for k, v in self.id_to_variable.items() if is_live(v)
}
self.store_attr_mutations = {
k: v for k, v in self.store_attr_mutations.items() if is_live(k)
}
def mutation(self, var):
self.check_allowed_side_effect(var)
if isinstance(var.mutable_local, MutableSideEffects):
var.mutable_local = MutableSideEffects(var.mutable_local.source, True)
def _get_modified_vars(self):
return [var for var in self.id_to_variable.values() if self.is_modified(var)]
def codegen_save_tempvars(self, cg: PyCodegen):
for var in self._get_modified_vars():
if isinstance(
var.mutable_local, (AttributeMutationExisting, AttributeMutationNew)
) and isinstance(var, variables.NewCellVariable):
cg.load_import_from(utils.__name__, "make_cell")
cg.extend_output(create_call_function(0, True))
cg.add_cache(var)
if isinstance(var.mutable_local, AttributeMutationNew):
var.mutable_local.source = LocalSource(cg.tempvars[var]) # type: ignore[attr-defined]
elif isinstance(var.mutable_local, AttributeMutationNew):
if isinstance(var, variables.AutogradFunctionContextVariable):
unimplemented("AutogradFunctionContextVariable escaped")
if "__call_nn_module_init" in self.store_attr_mutations.get(
var.mutable_local, {}
):
assert isinstance(var, variables.UnspecializedNNModuleVariable)
cg.load_import_from(utils.__name__, "nn_module_new")
else:
cg.load_import_from(utils.__name__, "object_new")
cg(var.mutable_local.cls_source)
cg.extend_output(create_call_function(1, True))
cg.add_cache(var)
var.mutable_local.source = LocalSource(cg.tempvars[var])
elif var in cg.tempvars:
assert cg.tempvars.get(var) is None
# subsequent usage should point to the original variable
cg(var.mutable_local.source)
cg.add_cache(var)
for ctx, args in self.save_for_backward:
cg(ctx.source)
cg.load_method("save_for_backward")
for arg in args:
cg(arg)
cg.extend_output(
[
*create_call_method(len(args)),
create_instruction("POP_TOP"),
]
)
def register_hook(self, tensor, hook, handle, name):
assert isinstance(tensor, variables.TensorVariable)
assert isinstance(hook, variables.VariableTracker)
assert (
isinstance(handle, variables.RemovableHandleVariable)
and handle.mutable_local
)
assert hasattr(torch.Tensor, name)
idx = len(self.tensor_hooks.keys())
# duplicate index possible because of self.remove_hook()
while idx in self.tensor_hooks:
idx += 1
self.tensor_hooks[idx] = (tensor, hook, handle, name)
assert not handle.idx
handle.idx = idx
def remove_hook(self, idx):
del self.tensor_hooks[idx]
def codegen_hooks(self, cg):
for (
tensor,
hook,
handle,
name,
) in self.tensor_hooks.values():
# Note: [On tensor.register_hook]
#
# register_hook on a tensor, AKA backward hooks, have slightly nuanced differences in how they are implemented
# when it comes to hooks on objects with sources (inputs, params) vs objects without sources (intermediaries).
#
# For tensors with a source, we bypass direct inclusion of register_hook calls in the graph.
# Instead, these are tracked and stashed as a global variable, enabling their association with tensors in
# the residuals. During dynamo's frame creation, these hooks are invoked seamlessly on known reconstructible/fetch-able
# tensors. Because a source indicates knowledge of this object outside the torch compile region, and
# because we are running residuals firmly before .backward() can be run, it is sound to invoke
# `register_hook` on a known tensor.
#
# For tensors without a source, we support a limited subset of hooks. Global functions only, and
# compiled_autograd must be enabled or we will graph break.
#
# Handling the Handle: When a user retains the register_hook result in a handle, we intercept the
# STORE_FAST operation to record the user-designated local variable name. This ensures the reconstructed
# bytecode retains this name. If no handle is defined, we simply pop the generated value to keep the
# stack intact.
#
# Dynamo Tensor Hooks Workflow:
# - Functions passed to register_hook are lifted globally.
# - For tensors with sources:
# - In the "side_effects" phase of codegen, we iterate over tensors with hooks to:
# - Generate the tensor.
# - Issue a register_hook call on the tensor, linking to the globally stored function.
# - Incorporate a handle if one was established in the eager phase.
# - For tensors without sources:
# - We don't generate any instructions for registering a hook.
# - Handles from intermediary hooks are NYI.
# - We produce a call function that utilizes the trace_wrapped higher order op, closing over it.
# - We then manually insert the call function above into the graph.
# - The handle's exact user-specified name, "user_code_variable_name", is discerned and associated during STORE_FAST.
assert tensor.source, "Hooks on non input tensors NYI - should not get here"
cg(tensor)
cg.extend_output([cg.create_load_attr(name)])
cg(hook)
cg.extend_output(create_call_function(1, True))
# Adding the handle to the cache means RemovableHandleVariable().reconstruct() will
# be associated with the return value of register_hook(). This consumes the top of stack.
cg.add_cache(handle)
def codegen_update_mutated(self, cg: PyCodegen):
suffixes = []
for var in self._get_modified_vars():
if isinstance(var, variables.ListVariable):
# old[:] = new
cg(var, allow_cache=False)
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.extend_output(
[
cg.create_load_const(None),
cg.create_load_const(None),
create_instruction("BUILD_SLICE", arg=2),
]
)
suffixes.append([create_instruction("STORE_SUBSCR")])
elif isinstance(var, variables.ConstDictVariable):
cg.tx.output.update_co_names("clear")
cg.tx.output.update_co_names("update")
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.extend_output([create_load_method("update")])
cg(var, allow_cache=False)
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.extend_output([create_load_method("clear")])
suffixes.append(
[
*create_call_method(0), # clear
create_instruction("POP_TOP"),
*create_call_method(1), # update
create_instruction("POP_TOP"),
]
)
elif self.is_attribute_mutation(var):
for name, value in self.store_attr_mutations.get(
var.mutable_local, {}
).items():
if isinstance(var, variables.NewGlobalVariable):
cg.tx.output.update_co_names(name)
cg(value)
assert isinstance(var.mutable_local.source, GlobalSource) # type: ignore[attr-defined]
suffixes.append(
[create_instruction("STORE_GLOBAL", argval=name)]
)
elif name == "__call_nn_module_init":
pass # handled in codegen_save_tempvars
elif isinstance(value, variables.DeletedVariable):
if isinstance(
var.mutable_local, AttributeMutationExisting
) and hasattr(getattr(var, "value", None), name):
cg.tx.output.update_co_names(name)
cg(var.mutable_local.source)
suffixes.append(
[create_instruction("DELETE_ATTR", argval=name)]
)
elif (
isinstance(var, variables.UserDefinedObjectVariable)
and var.needs_slow_setattr()
):
# __setattr__ is defined on this object, so call object.__setattr__ directly
cg.load_import_from("builtins", "object")
cg.load_method("__setattr__")
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg(variables.ConstantVariable(name))
cg(value)
suffixes.append(
[*create_call_method(3), create_instruction("POP_TOP")]
)
else:
cg.tx.output.update_co_names(name)
cg(value)
cg(var.mutable_local.source)
suffixes.append([create_instruction("STORE_ATTR", argval=name)])
elif isinstance(var, variables.TupleIteratorVariable):
for _ in range(var.index):
cg.load_import_from(utils.__name__, "iter_next")
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.call_function(1, True)
cg.pop_top()
else:
raise AssertionError(type(var))
# do all the actual mutations at the very end to handle dependencies
for suffix in reversed(suffixes):
cg.extend_output(suffix)
def is_empty(self):
return not (
any(map(self.is_modified, self.id_to_variable.values()))
or self.tensor_hooks
or self.save_for_backward
or self.tensor_hooks
)
def clear(self):
self.keepalive.clear()
self.id_to_variable.clear()