So this fixes at least two issues:
1) When we are invoking inductor backend, we apply pre-grad passes which try to find correct fake mode to use. In the nested case, we will run into clash when there is closure variable in the inductor region because non-strict would have fakified this variable before hand and inner torch.compile would have created a new fresh fake mode. This is not a problem in regular torch.compile because inner torch.compile gets ignored. I don't know if we are supposed to inherit fake mode from parent context in this case. But we can avoid this problem if we just default to eager backend which is fine in this case because the point of export is to capture aten operators. Going to inductor would mean we will lose inner torch.compile ops.
2) There is custom torch function modes in export that track number of torch fns executed and inner compile itself doesn't work because of guard failure as this mode state gets changed. I noticed torch.cond fixes this problem by carefully stashing the torch function mode and defer it in the backend. So the correct thing to do here is just re-use torch.cond implementation unconditionally.
So the things i did for fixing above were:
1) Always default to eager backend when compile is invoked inside export. I needed to make how torch.cond sets up the fresh tracing env into an util that can be shared.
2) The previous eager backend for torch.cond was wrong because the context managers didn't actually persist until the backend is invoked.
3) torch.cond used only disable TorchFunctionMetadata tf mode and stash it for later, but in fact, we should do both TorchFunctionMetadata and PreDispatchTorchFunctionMode.
With above fixes, we are able to export flex attention in export.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164171
Approved by: https://github.com/ydwu4
This PR moves the call to copy the generated code from `/tmp/...` so that it is still called if attempting to compile the generated code fails. In both cases now, the generated code will be copied across to `torch_compile_debug/run_.../torchinductor/output_code.py` which makes debugging bad generated code easier.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/161615
Approved by: https://github.com/eellison
This pull request adds support for running operator microbenchmarks on ROCm (AMD GPU) environments in the CI workflow. The main changes involve introducing new build and test jobs for ROCm in the `.github/workflows/operator_microbenchmark.yml` file.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164173
Approved by: https://github.com/huydhn
We want to refactor the internal bookkeeping of DeviceMesh so that:
Simply the bookkeeping logics and make it generic enough so that it is easy to support new transformations like flatten noncontiguous dim, reshape and unflatten. (We leveraged the CuTe layout). This new layout also let us handle non-contiguous slicing, flatten, transpose possible.
Concretely, in this PR, we do the following:
1. Use the `_MeshLayout` to handle all index operations rather use a map to record mesh dims.
2. Removed `flatten_name_to_root_dims`, because now we can directly get layout from a flattened device mesh.
3. Replaced `_get_slice_mesh_dims` with `_get_slice_mesh_layout`.
4. Use the newly added function `check_overlap` to check layout overlap.
5. Use a new function `to_remapping_tensor` to use layout ranks as indices when the mesh tensor is not representable as CuTe. The reason is that layout acts as a backend of mesh tensor bookkeeping (indexing indices), it needs to be used as indices for remap back to the mesh tensor for new DeviceMesh generation and backend init. For example, in the case of 2K to 4K, the underlying layout is (2K, 1) but the actual value of the mesh tensor is [2K, 2K+1, ....,]. While flattening, slicing, we need to remap the layout back to the new mesh tensor so it maps the actual device allocation. For example, in the 2K to 4K case, if the shape is (1K, 1K) with dim_names ("dp", "tp"). Then when slicing "tp", the mesh tensor should be (2K, 2K+1, ..., 3K-1) or (3K, 3K+1, ... 4K-1). not the global ranks generated from the layout. (1K, 1).
Verified that loss curve is very close for DeepSeekV3 on torchtitan, note that exact same match is challenging because even if we run the baseline twice, the loss curve does not exactly match.
<img width="1113" height="490" alt="image" src="https://github.com/user-attachments/assets/7877b5a4-337e-4ad8-b878-2378f4f0f38d" />
The PR looks big indeed but we don't change any existing behavior of DeviceMesh, so it is a pure refactor.
With this refactoring we also enabled the slicing and flatten of non-contiguous dims of a device mesh which is hard to implement without cute layout.
This is a continue of https://github.com/pytorch/pytorch/pull/161106 (original one got messed with EasyCLA)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/163213
Approved by: https://github.com/lw, https://github.com/fegin
Modified `multimem_one_shot_all_reduce_out` function to accept a `root` argument, making it a `multimem_reduce` op.
The original `multimem_one_shot_all_reduce` op becomes a caller of the `multimem_reduce`, with each rank providing its own rank id as root.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164517
Approved by: https://github.com/ngimel
`grad_dtype` is a new attribute on Tensor to control gradient dtype:
- Access/setting is leaf-only.
- grad_dtype is respected when (1) when assigning to .grad, and (2) in the engine after the previous node produces incoming gradients for AccumulateGrad. (See table below for details)
- Not setting grad_dtype preserves the current behavior. Accessing it returns `t.dtype`
- `grad_dtype` cannot be set when there is already a `.grad` present and the dtypes conflict.
| `grad_dtype` setting | Setting `.grad` manually | Incoming gradient from autograd engine |
|-----------------------|--------------------------|-----------------------------------------|
| **Default (tensor’s dtype)** | `.grad` must match tensor’s dtype | Engine casts incoming grad to tensor’s dtype |
| **Set to specific dtype** | `.grad` must match that dtype | Engine casts incoming grad to the specified dtype |
| **Set to `None`** | `.grad` may be any dtype | Engine does not cast; accepts incoming grad dtype as-is |
Pull Request resolved: https://github.com/pytorch/pytorch/pull/162815
Approved by: https://github.com/albanD
Fixes#162129. Added validation in _rank_not_in_group() to check if ```FakeProcessGroup``` is properly initialized before use, raising a clear error message if ```torch.distributed.init_process_group(backend='fake')``` hasn't been called first.
This prevents silent failures and ensures proper dispatch system integration for all distributed operations.
Added test case test_fake_process_group_direct_usage_error() that validates the error is raised for ```all_reduce``` and ```all_to_all_single``` operations.
Please let me know if additional distributed operators should be tested or if any other updates are needed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/163665
Approved by: https://github.com/ezyang
**Summary**
Raise error when the `local_tensor` argument passed to `DTensor.from_local` is
a DTensor, this prevents users from accidentally calling `from_local` over a DTensor
object.
The error message is organized in this way:
```
the local_tensor argument only accepts torch.Tensor but got <class 'torch.distributed.tensor.DTensor'> value.
```
**Test**
`pytest test/distributed/tensor/test_dtensor.py -k test_from_local`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164496
Approved by: https://github.com/ezyang
it was previously quite misleading since it looks like the inputs to the
dynamo graph are plain tensors when in reality they are tensor subclasses
before
```
class GraphModule(torch.nn.Module):
def forward(self, L_input_batch_inputs_: "i64[2, 512][512, 1]cuda:0", L_self_parameters_weight_: "f32[202048, 256][256, 1]cuda:0"):
```
after
```
class GraphModule(torch.nn.Module):
def forward(self, L_input_batch_inputs_: "DTensor(i64[2, 512][512, 1]cuda:0)", L_self_parameters_weight_: "DTensor(f32[202048, 256][256, 1]cuda:0)"):
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164403
Approved by: https://github.com/ezyang
Shared memory is allocated by creating a file in /dev/shm (by default) that can run out of space. Pytorch reserves the file size by calling ftruncate() that creates a sparse file, so it succeeds even if sufficient disk space is not available.
This could lead to a situation when a shared memory region is successfully created but a subsequent access to a shared memory page results in SIGBUS due to the disk being full.
Using posix_fallocate() instead of ftruncate() eliminates this problem because the former syscall always allocates space and it returns an error if the disk is full.
Related to https://github.com/pytorch/pytorch/issues/5040
Pull Request resolved: https://github.com/pytorch/pytorch/pull/161910
Approved by: https://github.com/mikaylagawarecki
Changelog:
1. When we run into an operation we didn't proxy, we end up emitting fake constants. We error under a config and we disable the config for some internal users. The reason we want to error is this signals a coverage problem we need to address but at the same time, we don't wnat to be disruptive to already working flows.
2. Previous attribute mutation detection logic in non-strict didn't account for nested module structure. This fixes silent incorrectness issue of exporting esm and qwen in non-strict and some torchbench models like levit_128 and demucs.
3. Previous logic didn't work on the cases where we mutate a container attribute as the previous approach used to pytree over old and new attributes resulting in length mismatch. We gracefully handle this now.
Differential Revision: [D83673054](https://our.internmc.facebook.com/intern/diff/D83673054)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164372
Approved by: https://github.com/avikchaudhuri
Add `struct AOTInductorConstantMapEntry` to represent the constant map in AOTI Model. We cannot use `std::unordered_map` for cross-compilation, because it is not ABI stable.
it will be tested when we test `update_user_managed_constant_buffer` for windows cross-compilation
Example usage:
```
// Load constants. Create random constants here.
auto* fc1_w = new slim::SlimTensor(slim::empty({16, 10}, c10::kFloat, c10::Device(c10::kCUDA, 0)));
fc1_w->fill_(1.0);
.....
// Build pairs
std::vector<AOTInductorConstantPair> constants{
{"fc1_weight", fc1_w},
{"fc1_bias", fc1_b},
{"fc2_weight", fc2_w},
{"fc2_bias", fc2_b},
};
// Call runtime (pass raw pointer + size)
update_user_managed_constant_buffer_abi(
container_handle,
constants.data(),
constants.size(),
/*use_inactive=*/false,
/*validate_full_update=*/true);
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/163819
Approved by: https://github.com/desertfire
