Fixes#160752
# Background:
`torch.func.jacfwd` is implemented as vmap over forward-mode JVP. With torch.compile(dynamic=True), FakeTensor + SymInt shape reasoning is used while tracing through the transform. The old vmap rule for one_hot decomposed into “zeros_symint + scatter,” which interacted poorly with the transform stack and dynamic shapes, leading to failures mid-trace. Using a functional equality construction makes one_hot composable with vmap/JVP and friendly to dynamic shape tracing.
# Changes:
- functorch vmap batching rule for `aten::one_hot` now uses a purely functional formulation:
- Replace “zeros + scatter” with eq(self.unsqueeze(-1), arange(num_classes)).to(kLong) under FuncTorchBatched.
- one_hot native path remains unchanged for regular eager; vmap transform no longer relies on scatter, which was fragile under dynamic shape tracing.
The minimal repro from the issue is now fixed:
```python
import torch
import torch.nn.functional as F
MAX, BATCH = 3, 37
def func(x, idxs):
return x.square() * F.one_hot(idxs, MAX)
def jacfunc(x, idxs):
return torch.func.jacfwd(func, argnums=0)(x, idxs)
idxs = torch.randint(MAX, (BATCH,), dtype=torch.int64)
x = torch.rand((BATCH, MAX), dtype=torch.float64)
# eager
out_eager = jacfunc(x, idxs)
# compiled dynamic
jacfunc_c = torch.compile(jacfunc, dynamic=True)
out_comp = jacfunc_c(x, idxs)
torch.testing.assert_close(out_eager, out_comp)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/160837
Approved by: https://github.com/guilhermeleobas, https://github.com/zou3519
Summary:
The `nDims` variable is mutated inside the loop but never restored to its original value.
This affects subsequent iterations of the outer loop.
Each batch iteration may get incorrect `nDims` after the first batch.
Test Plan: CI
Reviewed By: ngimel
Differential Revision: D84612194
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165446
Approved by: https://github.com/ngimel
Summary: If a function is wrapped with functools, we should not look at the wrapped function signature but rather the wrapper, since we need to construct the frame for the top level function here.
Test Plan: test_decorated_function_with_functools_wrap_aot
Differential Revision: D84626752
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165454
Approved by: https://github.com/yiming0416
Summary: This diff fixes a stress test failure by adding a new binary echo4.py and modifying the existing echo1.py binary. The changes are made in both fbcode and xplat directories. The api_test.py file is updated to use the new echo4.py binary, and the BUCK file is updated to include the new binary.
Test Plan:
```
buck test -j 18 'fbcode//mode/opt' fbcode//caffe2/test/distributed/elastic/multiprocessing:api_test -- --exact 'caffe2/test/distributed/elastic/multiprocessing:api_test - test_binary_redirect_and_tee (api_test.StartProcessesListAsBinaryTest)' --run-disabled --stress-runs 20 --record-results
```
```
buck test -j 18 'fbcode//mode/opt' fbcode//caffe2/test/distributed/elastic/multiprocessing:api_test -- --exact 'caffe2/test/distributed/elastic/multiprocessing:api_test - test_binary (api_test.StartProcessesListAsBinaryTest)' --run-disabled --stress-runs 20 --record-results
```
https://www.internalfb.com/intern/testinfra/testrun/17732923648474906https://www.internalfb.com/intern/testinfra/testrun/15481123834815653
Differential Revision: D83623694
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164353
Approved by: https://github.com/d4l3k
**Summary**
Today, the only way to have variable sequence length support in PyTorch attention is through nested tensors [here](https://docs.pytorch.org/tutorials/intermediate/scaled_dot_product_attention_tutorial.html#nestedtensor-and-dense-tensor-support). We also want to add an explicit lower-level API that provides variable sequence length support without padding/masking in SDPA.
This PR builds out `varlen_attn`, the public API that users can call for the forward method, and `_varlen_attn`, the private API that calls into the Flash Attention/cuDNN backend.
**Benchmarking**
To benchmark, we compare runtime and TFLOPs against the current SDPA approach with padding.
Settings:
- 1 H100 machine
- `batch_size=8`, `max_seq_len=2048`, `embed_dim=1024`, `num_heads=16`
- dtype `torch.bfloat16`
- `is_causal=False`
- for variable length, we set sequences to be random multiples of 64 up to `max_seq_len`
- 100 runs
| | Variable Length API | SDPA |
|--------|--------------------|----------|
| Runtime | 0.21750560760498047 ms | 0.43171775817871094 ms |
| TFLOPs | 231.812 | 320.840 |
The sparsity is 0.453 which we can see matches the speedup we get from Varlen (approx 50%). TFLOPs remains around the same, with SDPA slightly larger due to potential higher overhead and total flops scaling with sequence length.
**Testing**
Run `python test/test_varlen_attention.py` for unit tests where we verify basic functionality and confirm numerical match between varlen outputs vs SDPA.
**Next steps**
Next steps from this PR (higher in the stack) include registering the private API `_varlen_attn` as a custom op, implementing backward support, and enabling cuDNN with correct numerics.
(This stack builds on top of #162326)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164502
Approved by: https://github.com/v0i0, https://github.com/drisspg
This stack is going to turn off functionalization and turn on the default partitioner, so I'm going to separate out a few changes before turning off functionalization in our OpInfo tests:
(1) run our tests with input mutations allowed inside the graph
(2) run our tests with the default partitioner
(3) run with functionalization off
(4) (later) make the tests properly test for bitwise equivalence
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165327
Approved by: https://github.com/ezyang
I just want to print CommDebugMode and know if there is communication. implementing `__repr__` for `print(comm_mode)`
```
comm_mode = CommDebugMode()
with comm_mode:
out = torch.mm(inps, weight)
print(comm_mode)
# CommDebugMode(get_total_counts()=0)
```
Tags:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165006
Approved by: https://github.com/anshul-si
ghstack dependencies: #165024
When `repeat_interleave` is decomposed into:
```bash
cumsum = repeat.cumsum(0)
pos = torch.arange(output_size, device=repeat.device)
indices = torch.searchsorted(cumsum, pos, right=True)
```
`searchsorted` op with `right=True` returns the insertion point after matching elements. When query values `pos` are `>= cumsum[-1]`, searchsorted returns `len(cumsum)`, which is out of bounds for indexing (valid range: `[0, len(cumsum)-1]`). These invalid indices trigger CUDA device-side assert errors in downstream indexing operations.
This fix adds clamping to ensure all indices stay within the valid range [0, repeat.size(0)-1].
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165368
Approved by: https://github.com/mlazos
Use the existing benchmark infra to get some signals for AOT precompile pass rate on OSS models. Here we also measure and log the loading time.
```
python ./benchmarks/dynamo/huggingface.py --accuracy --inference --aot-precompile
python ./benchmarks/dynamo/timm_models.py --accuracy --inference --aot-precompile
python ./benchmarks/dynamo/torchbench.py --accuracy --inference --aot-precompile
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164906
Approved by: https://github.com/zhxchen17
Summary: Add note mentioning which scaling type pairs are supported in Inductor ATen, since this was a source of confusion and also informs which scaling strategies we choose to support for other backends, like Triton.
Test Plan: n/a
Reviewed By: lw
Differential Revision: D84522373
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165450
Approved by: https://github.com/NikhilAPatel
We noticed that disabling autorevert in any and all ci:sevs is too impactful, as ci: sevs are sometimes created just to communicate an action or a impactful change. But sometimes durring a SEV we might not want to disable autorevert anyways, a example is a ci: sev impacting jobs we don't use as basis for autorevert.
So, a note is added reminding the ci:sev author to optionally add this tag to disable auto-revert
Note: using this opportunity to fix the ci: disable-autorevert issues. As it is best for the title to be simple and the displayed message in the GitHub interface to be decorated with emoji :)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165459
Approved by: https://github.com/malfet
This is a cleaner implementation of opaque objects (https://github.com/pytorch/pytorch/pull/162660). Instead now we just need to do:
Call `register_opaque_type` to register the type as being "opaque" and allowed by custom ops. You also need to pass a unique name that maps to the type.
```python
class OpaqueQueue:
def __init__(self, queue: list[torch.Tensor], init_tensor_: torch.Tensor) -> None:
super().__init__()
self.queue = queue
self.init_tensor_ = init_tensor_
def push(self, tensor: torch.Tensor) -> None:
self.queue.append(tensor)
def pop(self) -> torch.Tensor:
if len(self.queue) > 0:
return self.queue.pop(0)
return self.init_tensor_
def size(self) -> int:
return len(self.queue)
register_opaque_type(OpaqueQueue, "_TestOpaqueObject_OpaqueQueue")
```
When creating the custom op, the schema will then use the unique name:
```python
self.lib = torch.library.Library("_TestOpaqueObject", "FRAGMENT")
torch.library.define(
"_TestOpaqueObject::queue_push",
"(_TestOpaqueObject_OpaqueQueue a, Tensor b) -> ()",
tags=torch.Tag.pt2_compliant_tag,
lib=self.lib,
)
@torch.library.impl(
"_TestOpaqueObject::queue_push", "CompositeExplicitAutograd", lib=self.lib
)
def push_impl(queue: OpaqueQueue, b: torch.Tensor) -> None:
assert isinstance(queue, OpaqueQueue)
queue.push(b)
```
Using the custom op:
```python
queue = OpaqueQueue([], torch.zeros(3))
torch.ops._TestOpaqueObject.queue_push(queue, torch.ones(3))
self.assertTrue(queue.size(), 1)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165004
Approved by: https://github.com/albanD
## Issue
During autotune, we're not applying size hints atomically for the example inputs used for benchmarking.
If there is unbacked symint showing up in inputs' strides, this might lead to CUDA IMA,
and this could be reproduced by the added unittest, with stride being `[128 * u0, 128, 1]` and unbacked fallback being 8192, after calling `benchmark_example_value`, we get back a tensor with stride as `[8192, 128, 1]` as opposed to `[128 * 8192, 128, 1]`
## Fix
Using the atomic API when trying to apply size hints to input tensor' strides.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/163660
Approved by: https://github.com/ColinPeppler
Summary: Apparently if I just do `tensor + eps` this turns into add.Tensor, which is bad because the constant Tensor ends up getting hoisted into an input, which is a bozo thing to do. Just make sure it's exactly compatible.
Test Plan:
```
buck run 'fbcode//mode/opt' fbcode//bolt/nn/executorch/backends/tests:qnn_test_ar1g1 bolt.nn.executorch.backends.tests.qnn_test_ar1g1.QnnTestAR1G1.test_RMSNorm
```
Reviewed By: tugsbayasgalan
Differential Revision: D84613184
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165437
Approved by: https://github.com/tugsbayasgalan
for pipeline parallel, we can have multiple FSDP roots (chunks)
```
model = nn.Sequential([chunk0, chunk1])
fully_shard(model.chunk0)
fully_shard(model.chunk1)
```
we can call `share_comm_ctx` to share all-gather, reduce-scatter, all-reduce cuda streams. this avoids inter-stream memory fragmentation
```
from torch.distributed.fsdp import share_comm_ctx
share_comm_ctx([model.chunk0, model.chunk1])
```
unit test: `pytest -s test/distributed/_composable/fsdp/test_fully_shard_training.py -k test_share_comm_context`
Summary:
Test Plan:
Reviewers:
Subscribers:
Tasks:
Tags:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165024
Approved by: https://github.com/mori360
When the autobucketing pass is registered as aot_eager backend `fw_compiler` and `bw_compiler`, this pr ensures the tensors are all-gathers on "cpu/cuda" device instead of "meta" device.
When we do `dist.all_gather_object`, it will create new bytestorage outside no_dispatch [here](a2e2e1d8c0/torch/distributed/distributed_c10d.py (L3303)), which is on meta device. Thus, I updated the code to use `unset_fake_temporarily`, which would gather RealTensor from other ranks.
It is needed to unblock the aot_eager+autobucketing pass in this [PR](https://github.com/pytorch/torchtitan/pull/1813).
Otherwise, I hit the error as follows:
```bash
traceback : Traceback (most recent call last):
File "/home/ruisizhang123/pytorch/torch/distributed/elastic/multiprocessing/errors/__init__.py", line 358, in wrapper
return f(*args, **kwargs)
File "/home/ruisizhang123/torchtitan/torchtitan/train.py", line 607, in train
self.train_step(data_iterator)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
File "/home/ruisizhang123/torchtitan/torchtitan/train.py", line 507, in train_step
loss = self.forward_backward_step(input_dict, labels)
File "/home/ruisizhang123/torchtitan/torchtitan/train.py", line 483, in forward_backward_step
pred = model_parts[0](inputs, **extra_inputs, **extra_args)
File "/home/ruisizhang123/pytorch/torch/_dynamo/eval_frame.py", line 418, in __call__
return super().__call__(*args, **kwargs)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
File "/home/ruisizhang123/pytorch/torch/nn/modules/module.py", line 1784, in _wrapped_call_impl
return self._call_impl(*args, **kwargs)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
File "/home/ruisizhang123/pytorch/torch/nn/modules/module.py", line 1795, in _call_impl
return forward_call(*args, **kwargs)
File "/home/ruisizhang123/pytorch/torch/_dynamo/eval_frame.py", line 901, in compile_wrapper
raise e.remove_dynamo_frames() from None # see TORCHDYNAMO_VERBOSE=1
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/ruisizhang123/pytorch/torch/_dynamo/output_graph.py", line 2359, in _call_user_compiler
raise BackendCompilerFailed(
self.compiler_fn, e, inspect.currentframe()
).with_traceback(e.__traceback__) from None
File "/home/ruisizhang123/pytorch/torch/_dynamo/output_graph.py", line 2334, in _call_user_compiler
compiled_fn = compiler_fn(gm, example_inputs)
File "/home/ruisizhang123/pytorch/torch/_dynamo/repro/after_dynamo.py", line 156, in __call__
compiled_gm = compiler_fn(gm, example_inputs)
File "/home/ruisizhang123/pytorch/torch/__init__.py", line 2441, in __call__
return self.compiler_fn(model_, inputs_, **self.kwargs)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/ruisizhang123/pytorch/torch/_dynamo/backends/common.py", line 117, in __call__
cg = aot_module_simplified(gm, example_inputs, **self.kwargs)
File "/home/ruisizhang123/pytorch/torch/_functorch/aot_autograd.py", line 1100, in aot_module_simplified
compiled_fn, _ = aot_stage2_compile(
~~~~~~~~~~~~~~~~~~^
aot_state,
^^^^^^^^^^
...<4 lines>...
inference_compiler,
^^^^^^^^^^^^^^^^^^^
)
^
File "/home/ruisizhang123/pytorch/torch/_functorch/_aot_autograd/graph_compile.py", line 257, in aot_stage2_compile
return aot_stage2_autograd(aot_state, aot_graph_capture)
File "/home/ruisizhang123/pytorch/torch/_functorch/_aot_autograd/graph_compile.py", line 1696, in aot_stage2_autograd
compiled_fw_func = aot_config.fw_compiler(fw_module, adjusted_flat_args)
File "/home/ruisizhang123/torchtitan/torchtitan/experiments/simple_fsdp/backend.py", line 35, in aten_autobucketing_reordering_pass
schedule_overlap_bucketing(gm)
~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^
File "/home/ruisizhang123/pytorch/torch/_inductor/fx_passes/overlap_scheduling.py", line 755, in schedule_overlap_bucketing
).run()
~~~^^
File "/home/ruisizhang123/pytorch/torch/_inductor/fx_passes/overlap_scheduling.py", line 358, in run
self._align_compute_nodes_runtime_estimations_across_all_distributed_ranks()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
File "/home/ruisizhang123/pytorch/torch/_inductor/fx_passes/overlap_scheduling.py", line 337, in _align_compute_nodes_runtime_estimations_across_all_distributed_ranks
dist.all_gather_object(
~~~~~~~~~~~~~~~~~~~~~~^
gathered_runtime_estimations, runtime_estimations, pg
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "/home/ruisizhang123/pytorch/torch/distributed/c10d_logger.py", line 82, in wrapper
return func(*args, **kwargs)
File "/home/ruisizhang123/pytorch/torch/distributed/distributed_c10d.py", line 3170, in all_gather_object
input_tensor, local_size = _object_to_tensor(obj, current_device, group)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/ruisizhang123/pytorch/torch/distributed/distributed_c10d.py", line 3079, in _object_to_tensor
byte_tensor = torch.ByteTensor(byte_storage).to(device)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
torch._dynamo.exc.BackendCompilerFailed: backend='compiler_fn' raised:
RuntimeError: Attempted to set the storage of a tensor on device "cpu" to a storage on different device "meta". This is no longer allowed; the devices must match.
Set TORCHDYNAMO_VERBOSE=1 for the internal stack trace (please do this especially if you're reporting a bug to PyTorch). For even more developer context, set TORCH_LOGS="+dynamo"
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165063
Approved by: https://github.com/eellison
Summary: For D84399286, failing ads ne deterministic tests now. These tests are especially brittle with subtle bitwise numerics changes. Will reenable for fbcode once e2e validation tests are performed
Test Plan: N/A
Differential Revision: D84514361
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165328
Approved by: https://github.com/izaitsevfb
The match for backward nodes might be in a different submod, so we should check all submod for potential matches.
In flex attention, this could happen if `mask_mod` has operations (such as index) that increase the seq_nr of the forward graph nodes. Then the backward flex_attention nodes cannot find a match in its own subgraph.
```
python test/functorch/test_aot_joint_with_descriptors.py -k preserve_annotate
```
Also tested on torchtitan joint_graph_runner branch. The flex_attention backward nodes are annotated now.
```
NGPU=8 CONFIG_FILE="./torchtitan/models/llama3/train_configs/debug_model.toml" LOG_RANK=0 TRAIN_FILE="torchtitan.train" TORCHFT_LIGHTHOUSE="http://localhost:29510" PYTORCH_ALLOC_CONF="expandable_segments:True" torchrun --nproc_per_node=8 --rdzv_backend c10d --rdzv_endpoint="localhost:0" --local-ranks-filter 0 --role rank --tee 3 -m torchtitan.train --job.config_file ./torchtitan/models/llama3/train_configs/debug_model.toml --model.name joint_graph_runner.llama3 --compile.enable --parallelism.data_parallel_shard_degree=2 --parallelism.tensor_parallel_degree=4 --model.flavor=debugmodel_flex_attn
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165202
Approved by: https://github.com/SherlockNoMad
Skip test_compiled_autograd_attribution on s390x
It fails both on s390x and x86_64 at least under some circumstances. Disable it for now until on s390x until it works reliably.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/163647
Approved by: https://github.com/malfet
