This PR implements tracing of with contexts with TorchFunction modes which have the default enter/exit behavior (ie pushing/popping the mode)
Typically the bytecode for a context manager looks like this during a graph break:
1. graph call
2. enter context
3. unsupported code
4. exit context
5. resume call
resume fn structure:
1. enter context
2. jump
...
3. exit context
The issue with torch function modes is that side effects will replay any mutations to the torch function stack performed during tracing. So, we do not need to enter and exit around the unsupported code in the original function (doing so would result in a duplicate torch function mode entry during execution of the unsupported code), and we don't need to enter again in the resume function (the mode that was pushed from the side effects bytecode would still be on the stack).
So for torch function modes the structure of our output code is this:
1. graph call
2. mutate tf mode stack to replay mutations
4. unsupported code
5. on exception restore stack
6. resume function
Then our resume fn looks like this:
1. no-op enter torch function mode
2. jump
3. exit tf mode
To implement the no-op enter of the torch function mode I added torch function mode in polyfill which no-op enters, but normally exits. This is needed because we still want to trace the with context in the resume function, and exit properly (the exit instructions will still be in the function, so we need to generate instructions to set up the context).
Separately from the bytecode, dynamo also tracks contexts on the block stack, which is how the SETUP_* instructions are implemented. Naturally at a graph break, we exit these block stacks to properly reset the contexts entirely, so that we can re-enter around the unsupported code soundly. However once again, in the torch function mode case, in the event of a graph we do not want to perform any exit side effects because we want to preserve the state of the mode stack as is so that we will properly update the stack with bytecode mentioned in the first section. If we exited here, dynamo would pop the mode off of the symbolic stack, and not update the true python torch function mode stack with the suffix bytecode. All in all, for torch function modes we enter exactly once, update the global torch function mode stack with side effects bytecode, re-read this stack when compiling the resume function, and exit exactly once in the resume function. This matches the semantics of eager exactly.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135422
Approved by: https://github.com/williamwen42
ghstack dependencies: #134732, #133137, #135443, #135444
This PR:
* Implements the pre-existing `nt.to_padded_tensor(padding_val)` ATen op via the FBGEMM kernel + appropriate view gymnastics (since that kernel only handles 2D values)
* Introduces a new `_nested_from_padded_tensor` op for the reverse conversion, implemented via the reverse FBGEMM kernel + view gymnastics
* Note: there is currently no public API for this; design booted to a future PR
TODO:
* ~~Propagate min / max sequence length via the new factory function `_nested_from_padded_tensor`~~
* ~~Verify that Inductor does computation fusion via test logic~~
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125947
Approved by: https://github.com/soulitzer
This PR:
* Implements the pre-existing `nt.to_padded_tensor(padding_val)` ATen op via the FBGEMM kernel + appropriate view gymnastics (since that kernel only handles 2D values)
* Introduces a new `_nested_from_padded_tensor` op for the reverse conversion, implemented via the reverse FBGEMM kernel + view gymnastics
* Note: there is currently no public API for this; design booted to a future PR
TODO:
* ~~Propagate min / max sequence length via the new factory function `_nested_from_padded_tensor`~~
* ~~Verify that Inductor does computation fusion via test logic~~
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125947
Approved by: https://github.com/soulitzer
reland of https://github.com/pytorch/pytorch/pull/133113
I have to create a new PR because the previous reverted PR could not either be rebased, or imported successfully :(
----
Moving DTensor to be in the public namespace, to formally add the documentation page that includes all the public APIs. This includes:
* many path renames and path import fixes
* a dedicated doc page without too much content yet (adding in the next PRs)
* To preserve the BC for users still using the torch.distributed._tensor, I added a shim script to redirect old path calls to the new module
The BC preserving is evidented by the fact that all DTensor tests are still working without changing the public imports. So it's safe to land the changes
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134203
Approved by: https://github.com/tianyu-l
TLDR; this PR supports exporting cond x inine_inbuilt nn modules flag by inling into tracing code in proxy_tensor.py _symbolic_trace.py (internally, the pattern is make_fx(record_module_stack)(torch.compile(f))).
We have two special treatments for following cases:
1. _ModuleStackTracer will wrap all the nn modules into _AttrProxy. This _AttrProxy has several subtiles which make it hard to inline in dynamo like overriding _modules with a property method and overrides the `__getattr__`, which mutates captured states when calling `__getattr__`.
Solution to this is that we unwrap the _AttrProxy and get its corresponding nn_module (a 1-1 correspondence). So that dynamo symbolically traces the original nn module instead of tracing _AttrProxy.
2. The tracer applies a bunch of patches the `__getattr__` and `__call__` of nn.Module for tracking reasons. This doesn't work well with dynamo. The immediate error we see is `torch._dynamo.exc.Unsupported: 'inline in skipfiles: WeakKeyDictionary.__contains__ | __contains__ /home/yidi/.conda/envs/pytorch/lib/python3.10/weakref.py` caused by a weakdict in PythonKeyTracer.
Solution to this is that we remove the patches during dynamo symbolic convert temporally. So that dynamo has a clean environment. make_fx will be trace the transformed bytecode of dynamo and patches nn modules there instead.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133731
Approved by: https://github.com/anijain2305
ghstack dependencies: #134775
The previous PR https://github.com/pytorch/pytorch/pull/133532 caused stuck compilation issue on internal models. In this 2nd attempt PR, we gate the trace_rules.py changes with `if not torch._dynamo.config.skip_fsdp_hooks:`, so that they don't take effect for current graph-break FSDP2 (which relies on the default config value `skip_fsdp_hooks=True`), and will only take effect when we are using Traceable FSDP2 (in which case the user needs to proactively set `skip_fsdp_hooks=False`).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134539
Approved by: https://github.com/ckluk2, https://github.com/yanboliang
The previous PR https://github.com/pytorch/pytorch/pull/133532 caused stuck compilation issue on internal models. In this 2nd attempt PR, we gate the trace_rules.py changes with `if not torch._dynamo.config.skip_fsdp_hooks:`, so that they don't take effect for current graph-break FSDP2 (which relies on the default config value `skip_fsdp_hooks=True`), and will only take effect when we are using Traceable FSDP2 (in which case the user needs to proactively set `skip_fsdp_hooks=False`).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134539
Approved by: https://github.com/ckluk2, https://github.com/yanboliang
Changes:
1. Move `polyfill.py` -> `polyfills/__init__.py`. It can be used as `polyfill.xxx` -> `polyfills.xxx`.
2. Move submodule loading from `polyfills/__init__.py` to `polyfills/loader.py`.
Merge `polyfill.py` and `polyfills/` packages. Each polyfill module have its own namespace for better code organization.
The ultimate goal is make `polyfills/__init__.py` empty and all polyfill functions move to its own namespace.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133977
Approved by: https://github.com/jansel
Add decorator `torch.compiler.substitute_in_graph` to register polyfill for unsupported C++ function to avoid graph break. This API provides an official way to add support for dynamo for third-party C extensions. Also, it can be used to simplify our implementation for `torch._dynamo.polyfill`.
5ee070266f/torch/_dynamo/variables/builtin.py (L97-L107)
Example:
```python
>>> import operator
>>> operator.indexOf([1, 2, 3, 4, 5], 3)
2
>>> torch.compile(operator.indexOf, fullgraph=True)([1, 2, 3, 4, 5], 3)
Unsupported: ...
>>> @torch.compiler.substitute_in_graph(operator.indexOf)
... def indexOf(sequence, x):
... for i, item in enumerate(sequence):
... if item is x or item == x:
... return i
... raise ValueError("sequence.index(x): x not in sequence")
>>> torch.compile(operator.indexOf, fullgraph=True)([1, 2, 3, 4, 5], 3)
2
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133712
Approved by: https://github.com/jansel
Add decorator `torch.compiler.substitute_in_graph` to register polyfill for unsupported C++ function to avoid graph break. This API provides an official way to add support for dynamo for third-party C extensions. Also, it can be used to simplify our implementation for `torch._dynamo.polyfill`.
5ee070266f/torch/_dynamo/variables/builtin.py (L97-L107)
Example:
```python
>>> import operator
>>> operator.indexOf([1, 2, 3, 4, 5], 3)
2
>>> torch.compile(operator.indexOf, fullgraph=True)([1, 2, 3, 4, 5], 3)
Unsupported: ...
>>> @torch.compiler.substitute_in_graph(operator.indexOf)
... def indexOf(sequence, x):
... for i, item in enumerate(sequence):
... if item is x or item == x:
... return i
... raise ValueError("sequence.index(x): x not in sequence")
>>> torch.compile(operator.indexOf, fullgraph=True)([1, 2, 3, 4, 5], 3)
2
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133712
Approved by: https://github.com/jansel
Add decorator `torch.compiler.substitute_in_graph` to register polyfill for unsupported C++ function to avoid graph break. This API provides an official way to add support for dynamo for third-party C extensions. Also, it can be used to simplify our implementation for `torch._dynamo.polyfill`.
5ee070266f/torch/_dynamo/variables/builtin.py (L97-L107)
Example:
```python
>>> import operator
>>> operator.indexOf([1, 2, 3, 4, 5], 3)
2
>>> torch.compile(operator.indexOf, fullgraph=True)([1, 2, 3, 4, 5], 3)
Unsupported: ...
>>> @torch.compiler.substitute_in_graph(operator.indexOf)
... def indexOf(sequence, x):
... for i, item in enumerate(sequence):
... if item is x or item == x:
... return i
... raise ValueError("sequence.index(x): x not in sequence")
>>> torch.compile(operator.indexOf, fullgraph=True)([1, 2, 3, 4, 5], 3)
2
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133712
Approved by: https://github.com/jansel
