For training graphs (when inputs require grad), previously, we would speculate the forward and backward graph to determine if there are any graph breaks, side effect and etc but would not actually use these speculated graphs. We would just insert a call function node on the graph and later rely on autograd's tracing.
This approach does not work for more generalized graphs like graphs that include user defined triton kernels because autograd is not able to do the higher order function conversation.
This PR speculates the forward and backward functions and emits them in a HOF that later gets used via templating mechanism.
While working on this PR, I have exposed some bugs in the current tracing due to trampoline functions losing the source information resulting in incorrect graphs being produced. I have fixed these source information bugs and killed the trampolines.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/116358
Approved by: https://github.com/jansel
Make ```SkipFilesVariable``` only handle function type, and route skipped classes to ```UserDefinedClassVariable```. The reasons behind this are:
* We'd like to remove ```is_allowed```, so the allowed/disallowed torch classes should have a proper place to handle. We can put them in either ```SkipFilesVariable``` and ```UserDefinedClassVariable``` under the current architecture, but it's confusing to have two places do one thing.
- Going forward, let's make ```SkipFilesVariable``` only handle functions, and probably I'll rename it to ```SkippedFunctionVariable``` in the following PRs.
- Let's do dispatch by value's type, all torch classes stuff would go to ```UserDefinedClassVariable``` in the next PR.
* We'd merge in_graph/skip/inline trace decision into the same API ```trace_rule.lookup```, so probably we have to limit the input to only function for better organizing ```VariableBuilder._wrap``` logics.
- Next step, I'll merge ```skipfiles.check``` into ```trace_rules.lookup```, and do the skipfile check before wrapping them into correct variable tracker.
- Though the ```TorchCtxManagerClassVariable``` is decided by ```trace_rules.lookup```, I'll refactor it out in the following PRs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/115963
Approved by: https://github.com/jansel
Make ```SkipFilesVariable``` only handle function type, and route skipped classes to ```UserDefinedClassVariable```. The reasons behind this are:
* We'd like to remove ```is_allowed```, so the allowed/disallowed torch classes should have a proper place to handle. We can put them in either ```SkipFilesVariable``` and ```UserDefinedClassVariable``` under the current architecture, but it's confusing to have two places do one thing.
- Going forward, let's make ```SkipFilesVariable``` only handle functions, and probably I'll rename it to ```SkippedFunctionVariable``` in the following PRs.
- Let's do dispatch by value's type, all torch classes stuff would go to ```UserDefinedClassVariable``` in the next PR.
* We'd merge in_graph/skip/inline trace decision into the same API ```trace_rule.lookup```, so probably we have to limit the input to only function for better organizing ```VariableBuilder._wrap``` logics.
- Next step, I'll merge ```skipfiles.check``` into ```trace_rules.lookup```, and do the skipfile check before wrapping them into correct variable tracker.
- Though the ```TorchCtxManagerClassVariable``` is decided by ```trace_rules.lookup```, I'll refactor it out in the following PRs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/115963
Approved by: https://github.com/jansel
1. Removes calls to `replace_all` and `clone` and makes VTs mutable.
2. Properly handles Tuple Iterator mutation. Previously TupleIterator variables would only be properly reconstructed if they were advanced at least once in a frame. On calls to `next`, the source information would be lost (due to constructing a new iterator without using builder), which would ensure that during codegen the variable would be reconstructed from scratch. Now that VTs are mutated, the source is never lost, so we need to properly track mutation and handle it by replaying calls to `next` at the end of the modified bytecode.
3. Added test for checking iadd side effects, this was missing in our unit test coverage.
4. Fixed two incorrect sources, DelayGraphBreakVariable, and UserMethodVariable both relied on setting the source to AttrSource(parent, name) at the callsite of `var_getattr`.
5. Fixed a bug in inplace adding for lists, it would set the resulting VariableTracker's source to `None` which would utilize a different reconstruct path in codegen. Now this is handled explicitly by reconstructing vars when allow_cache=`False`, so that during side effect replay, the mutated var is correctly updated.
In subsequent PRs:
* Refactoring side effect tracking to be significantly simpler (I think we only need an `is_modified` flag)
* Refactor `next_variables` iterator to match the signature of `next`
* Remove all references to `options` in the code
* Refactor VTs representing mutable collections to implement their own mutation update handling
* Remove clone and/or make it specific to lists for creating slices
* Add mutation tracking/replay for sets
* Add mutation tracking/replay for iter.py
* Removing setting source in builder (it's set at the top level after a var is returned)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/113725
Approved by: https://github.com/jansel
Removes always restore, assuming that a HOP will cleanup any leftover state from tracing fwd + bwd
This required a minor change to the autograd fn variable higher order op. If we are tracing forward DON'T add the call_function node into the main graph, since we are only tracing it for the purposes of speculation. Instead return the result directly to be passed to the backward for speculation. This was the only observable side effect on the output graph that I found.
Test plan:
test_smoke_from_test_autograd in test_autograd_function.py
Pull Request resolved: https://github.com/pytorch/pytorch/pull/115317
Approved by: https://github.com/voznesenskym, https://github.com/jansel
Updated version of #108885 addressing the review. In this PR:
- We add a VT.can_reconstruct utility that checks if VT.reconstruct()
does something.
- If functools.wraps(fn) is passed a `fn` that either has a source or
has .can_reconstruct() == True, then we stash the source (or the VT)
- Later on, we use the source (or VT.reconstruct) to actually
reconstruct the object in codegen.
Test Plan:
- New tests
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114279
Approved by: https://github.com/voznesenskym
This prepares the PR where we implement sets in terms of dicts.
To do so, rather than storing internally a dictionary that maps literals
to VariableTrackers, it stores (pretty much) a dictionary from VTs to VTs.
To do so, keys are wrapped in an opaque internal class `_Hashable`.
The Hashable class is opaque on purpose so that it fails hard if
if it inadvertently leaks back into user code.
We also found and fixed a number of latent bugs and inconsistencies
in the way dynamo checked what can be a dict key. More generally, we
make much clearer what are the things that need to be modified to add
a new supported key type to Dicts.
Fixes https://github.com/pytorch/pytorch/issues/107595
Fixes https://github.com/pytorch/pytorch/issues/111603
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111196
Approved by: https://github.com/jansel
AutogradFunctionContextVariable was mutating self._saved_tensors, which is generally not allowed since VariableTracker objects should be read-only and are frequently copied via apply/clone. This was causing some test failures up the PR stack.
This moves the mutation into a separate object that is not copied.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/112216
Approved by: https://github.com/voznesenskym
ghstack dependencies: #112122
Fixes https://github.com/pytorch/pytorch/issues/111031
The current design of autograd.Function tracing in dynamo is that we:
1) speculate fwd, and if its fine,
2) speculate bwd, and if its fine
3) install the .apply in the graph alongside fwd guards
The mechanism for doing so involves creating HOPs for fwd, bwd, and apply. The speculation for fwd and bwd create their own subtracer. This is fine, until a proxy created in fwd is used in bwd.
For a simple example, consider:
```
class Foo(Function):
@staticmethod
def forward(ctx, x):
ctx.x0 = x.size(0)
return x * 2
@staticmethod
def backward(ctx, grad_out):
return grad_out * ctx.x0
```
the value stored at `x0` is a proxy - but it is a proxy belonging to the fwd speculation subtracer. Rather than teaching it to the subtracer for bwd, we choose to create a subtracer that covers both fwd and bwd speculation.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111588
Approved by: https://github.com/zou3519
Did some easy fixes from enabling TRY200. Most of these seem like oversights instead of intentional. The proper way to silence intentional errors is with `from None` to note that you thought about whether it should contain the cause and decided against it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111496
Approved by: https://github.com/malfet
The motivation for removing this is already present in the pre-PR comments. Copying it
~~~
# NB - SuperSource is a weird one.
# it is our only source with 2 bases, so we use the objec
# as the base, rather than the type, since an invocation
# like super(Foo, foo) is represented here, the source object base is more spiritually
# aligned with the instance, rather than the type.
# This whole construction is questionable tho, and we should probably find a way to
# avoid this exception to our otherwise nice source parentage invariant.
~~~
Instead of using super(a, b), we can use `type(b).__mro__[index]`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110475
Approved by: https://github.com/jansel
