A series of directed perf improvements to drive down the dynamo tracing cost of
the given test. Before this PR stack the compile took about 60s, and after takes
30s. Individual improvements are listed below along with the approximate
improvement of that change.
Tested with this model:
```
@torch.compile(backend="eager")
def model_add(x, y):
out = x
for i in range(5000):
out = torch.add(out, y)
return out
```
This PR: Stop importing builder in the inner loop of `VariableTracker.build()`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/143056
Approved by: https://github.com/jansel
ghstack dependencies: #143066
Previously when Dynamo encounters a `functools.wrap(...)` call, it would
check `VariableTracker.can_reconstruct` and graph break if failed.
That has 2 issues:
1. Implementation of `can_reconstruct` is incorrect, since logic of
reconstructability isn't necessarily encapsulated in
`VariableTracker.reconstruct` -- for some VTs like `CellVariable`,
it's also in `SideEffects.codegen_save_tempvars`. This is exposed by
#134731.
2. We don't always need to reconstruct the result of
`functools.wrap(...)`, for those cases we don't want to give up
tracing by an early `con_reconstruct` check. Instead we could just
let it fall through, and graph break in the actual `reconstruct` call
later, if needed.
This patch removes the `can_reconstruct` check altogether. It was
introduced in #114279, but the added tests pass even without the check
now; this might be because of some recent bug fixing on cells and side
effects.
Fixes#134731, #141514.
D66838708
Pull Request resolved: https://github.com/pytorch/pytorch/pull/142000
Approved by: https://github.com/zou3519
Previously when Dynamo encounters a `functools.wrap(...)` call, it would
check `VariableTracker.can_reconstruct` and graph break if failed.
That has 2 issues:
1. Implementation of `can_reconstruct` is incorrect, since logic of
reconstructability isn't necessarily encapsulated in
`VariableTracker.reconstruct` -- for some VTs like `CellVariable`,
it's also in `SideEffects.codegen_save_tempvars`. This is exposed by
#134731.
2. We don't always need to reconstruct the result of
`functools.wrap(...)`, for those cases we don't want to give up
tracing by an early `con_reconstruct` check. Instead we could just
let it fall through, and graph break in the actual `reconstruct` call
later, if needed.
This patch removes the `can_reconstruct` check altogether. It was
introduced in #114279, but the added tests pass even without the check
now; this might be because of some recent bug fixing on cells and side
effects.
Fixes#134731, #141514.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/142000
Approved by: https://github.com/zou3519
As title, this also uncovered a few invalid use cases; the cases that
cause error are fixed in separate patches prior to this patch, and the
rest are fixed in this patch.
This patch also moves a few `.source` mutation to variable construction,
to increase the coverage of the validation.
Fixes#133027.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141717
Approved by: https://github.com/jansel
ghstack dependencies: #141713, #141714, #141715, #141902, #141716
This patch adds 2 simple methods `VariableTracker.is_mutable()` and
`VariableTracker.is_immutable()`, which helps clarify intention. For
instance, rather than writing
```python
if var.mutation_type:
...
```
After this patch one can write
```python
if var.is_mutable():
...
```
This patch also simplifies `mutation_type` propagation in some
`ListVariable` methods.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139341
Approved by: https://github.com/mlazos, https://github.com/anijain2305
ghstack dependencies: #139339, #139340
This patch addresses the renaming part of #133027, specifically, it
renames the following and adds documentation for relevant classes.
1. `VariableTracker.mutable_local` to `mutation_type`
2. `MatableLocal `to `ValueMutationNew`
3. `MutableSideEffects `to `ValueMutationExisting`
4. `MutableLocalSource` to `SourceType`
5. `MutableLocalSource.Local` to `New`
Note that (2), (3) and (5) are mainly to bring consistency between them
and `AttributeMutationNew`, `AttributeMutationExisting`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139339
Approved by: https://github.com/jansel, https://github.com/mlazos, https://github.com/anijain2305
## `VariableTracker::build()` hides the Builders
### The problem
In the current code, creating a `VariableTracker` involves choosing one of two `Builder` classes and either calling a method, or calling a constructor that creates an object that you immediately call, [like this](083c9149b7/torch/_dynamo/variables/functions.py (L761-L768)).
Variations on this code are repeated in many places.
More, the `Builder` classes have a lot of dependencies, so they have to be loaded late in the whole import process to avoid circular imports, so they end up being repeatedly imported at local scope.
### The solution
In this commit, the import from `builder` and the logic of choosing and calling the Builder class are hidden in a single static factory method, `VariableTracker.build()`, easier to reason about and to import.
This commit net lowers the total lines of code by over 150 lines by removing repetitive logic and unnecessary local imports.
**CHANGES:** Originally the name of the static method was `VariableTracker.create()` but a static method on a derived class, `LazyVariableTracker.create()` now exists with a different signature that's irreconcilable, so the new static method was renamed to `VariableTracker.build()`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135714
Approved by: https://github.com/jansel
Need to revert due to internal hangs: S437700
This reverts commit b6c1490cc0.
Revert "[dynamo] implement IteratorVariable and polyfill fallbacks for enumerate (#131725)"
This reverts commit 2576dbbc35.
Revert "[dynamo] add itertools repeat/count bytecode reconstruction (#131716)"
This reverts commit 35b4de32fa.
Revert "[dynamo] add lazy IteratorVariable implementations for map and zip (#131413)"
This reverts commit 7d282d8755.
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/132528
Approved by: https://github.com/ZainRizvi
Need to revert due to internal hangs: S437700
This reverts commit b6c1490cc0.
Revert "[dynamo] implement IteratorVariable and polyfill fallbacks for enumerate (#131725)"
This reverts commit 2576dbbc35.
Revert "[dynamo] add itertools repeat/count bytecode reconstruction (#131716)"
This reverts commit 35b4de32fa.
Revert "[dynamo] add lazy IteratorVariable implementations for map and zip (#131413)"
This reverts commit 7d282d8755.
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/132528
Approved by: https://github.com/ZainRizvi
Fixes https://github.com/pytorch/pytorch/issues/130750.
Repro of lazy/eager `map` discrepancy without `islice`:
```python
def fn(a, b):
y = 1
def f(x):
nonlocal y
y += 1
return x
l = list(zip([a, b], map(f, [1, 2, 3, 4])))
return a + y
```
The major change is that we implement `MapVariable` and `ZipVariable` based on `IteratorVariable`. Before, `map` and `zip` were being traced by immediately unpacking the result as a `TupleVariable`, which is wrong in cases such as the example above.
`MapVariable`s are not allowed to be unpacked while `ZipVariable`s can only be unpacked if all of its iterables can also be unpacked.
We also add new `[has_]force_unpack_var_sequence` methods to `VariableTracker` for the case where it is safe to unpack the entire sequence lazily, e.g., when building a list from a map (i.e. `list(map(f, ...))`).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/131413
Approved by: https://github.com/anijain2305
`unimplemented` is a function that raises an error, so
`raise unimplemented(...)` never reaches the `raise`.
Another related issue is that `raise unimplemented(...) from e`
doesn't attach the exception cause correctly. I fix this by adding
a `from_exc` argument to `unimplemented`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/122136
Approved by: https://github.com/lezcano
I was originally trying to solve https://github.com/pytorch/pytorch/issues/120799 but got sidetracked along the way.
This PR contains a couple fixes. Let me know if you want me to split them up!
- Properly handle invalid user code when "super()" is called from non-method/classmethod. It will now properly raise the same error as CPython
- Fix base VariableTracker `__str__` method shadowing all `__repr__` methods defined in subclasses
- Fix accessing a classmethod on a user object to bind "cls" and not "self"
- Fix custom class handling of super() call to properly handle mixed regular/class/static methods
Locally , test_repros.py -k test_batch_norm_act still fails where the generated graph module is:
```
Call using an FX-traced Module, line 8 of the traced Module's generated forward function:
x = self.forward(l_x_); self = l_x_ = None
x_1 = self.L__self___act(x); x = None
```
note that "self" is being unset on the first line even though it is used on the second one.
For reference, this is the test c268ce4a6d/test/dynamo/test_repros.py (L1368-L1369)
I cannot figure out where the generated forward function comes from though, any hint would be welcome!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/121365
Approved by: https://github.com/jansel
