Fixes https://github.com/pytorch/pytorch/issues/93468
There's a few extra tests that are sort of unrelated, but I ended up writing them while working on the fix and decided to keep them. The big idea here is to split the `_check` so that `expect_true` works; I could have probably also improved the symbolic reasoning but I'm lazy. One small logging fix too.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110979
Approved by: https://github.com/Skylion007
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
This PR adds a test for the previous PR in this stack: #109904. In summary, it calls
functions decorated with `@record_shapeenv_event`, that don't have an explicit `ShapeEnv`
parameter, with arguments that don't hold a `ShapeEnv` instance.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/109944
Approved by: https://github.com/ezyang
This PR adds a test for the previous PR in this stack: #109904. In summary, it calls
functions decorated with `@record_shapeenv_event`, that don't have an explicit `ShapeEnv`
parameter, with arguments that don't hold a `ShapeEnv` instance.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/109944
Approved by: https://github.com/ezyang
ghstack dependencies: #109904
This PR fix the `is_typing` function: checks whether a value is an instance of a class
from the `typing` package.
This reverts commit b09c09f7bb3adb6a5b8a107a5b96757b569daa8d.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/109201
Approved by: https://github.com/ezyang
When you inplace matmul two one dimensional numpy arrays, numpy=="1.24.3" gives
```
TypeError: In-place matrix multiplication is not (yet) supported. Use 'a = a @ b' instead of 'a @= b'.
```
but numpy=="1.25.2" gives
```
ValueError: inplace matrix multiplication requires the first operand to have at least one and the second at least two dimensions.
```
This diff makes it so that newer versions of numpy does not fail on this test because we do not catch ValueError.
An alternative solution would be to update the test cases to be 2 dimensional, but that would have impact on other operators being tested.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/109087
Approved by: https://github.com/jansel
**Motivation:**
We try to make torch.cond use torch.compile automatically so that we could error out when there is side-effects in the branches and correctly handle the closures.
Before this PR, we have a warning if we don't turn on a config raise_on_backend_change (turning it on gives us an error) for the following code:
```python
def foo()
# Inside torch.cond, we'd like to do something like
torch.compile(foo, backend="eager", fullgraph=True)(...)
...
# Users may then call torch.compile somewhere else.
# Dynamo will use the cached code of foo for "eager" backend
# but we expect dynamo to recompile with "inductor" backend.
torch.compile(foo, backend="inductor")(...)
```
This PR adds a BACKEND_MATCH guard. Effectively, it implements a per-backend cache. In the above example, the cached code for "eager" won't work for "inductor" due to guard check failures and the second torch.compile will do a re-compilation. In the future, it might be useful to have something like a configuration guard that guards against dynamo configuration changes across different compiles (e.g. compile a function with fullgraph=False then compile it again with fullgraph=True).
**Implementation:**
1. We add a guarded_backend_cache and check the most_recent_backend against the backend associated with cached code. We also remove the raise_on_backend_change flag.
Note: More lines are printed for debug log due to newly added context manager and guard adds .
**Test Plan:**
Removed original tests that raise on different backend and add a new test to test whether the BACKEND_MATCH guard can guard against backend change.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107337
Approved by: https://github.com/jansel
# Summary
## PR Dependencies
I don't use ghstack :( this is a PR where it would have been helpful. That beings said I am going to peel off some PRs to make reviewing this easier:
- [x] Separate build flags for Flash and MemEff: #107985
### Description
This pull request updates the version of _scaled_dot_product_flash_attention from version 1 to version 2. The changes are based on the flash attention code originally authored by @tridao
### Changes Made
The majority of the changes in this pull request involve:
- Copying over the flash_attention sources.
- Updating header files.
- Removing padding and slicing code from within the flash_attention kernel and relocating it to the composite implicit region of the SDPA. This was need to make the kernel functional and appease autograd.
- Introducing a simple kernel generator to generate different instantiations of the forward and backward flash templates.
- Adding conditional compilation (ifdef) to prevent building when nvcc is invoked with gencode < sm80.
- Introducing a separate dependent option for mem_eff_attention, as flash_attention v2 lacks support for Windows and cannot be built for sm50 generation codes.
- Modifying build.sh to reduce parallelization on sm86 runners and to lower the maximum parallelization on the manywheel builds. This adjustment was made to address out-of-memory issues during the compilation of FlashAttentionV2 sources.
- Adding/Updating tests.
### Notes for Reviewers
This is not a fun review, and I apologize in advance.
Most of the files-changed are in the flash_attn/ folder. The only files of interest here IMO:
- aten/src/ATen/native/transformers/cuda/flash_attn/flash_api.cpp
- aten/src/ATen/native/transformers/cuda/flash_attn/kernels/generate_kernels.py ( this has been incorporated upstream to flash-attention github)
There are a number of files all related to avoiding OOMs in CI/CD. These are typically shell scripts.
### Follow up items
- Include the updates from e07aa036db and 9e5e8bc91e | https://github.com/pytorch/pytorch/issues/108108
### Work Items
- [x] I don't think Windows will be supported for 3.1.0 - Need to update cmakee
- [x] Let multi_query/attention pass through and test | UPDATE: I have the fast path implemented here: https://github.com/pytorch/pytorch/pull/106730 but since this will require changes to semantics of math to call repeat_interleave, I think this should be done as a followup.
- [x] Had to drop cutlass back to 3.0.0 to get it to compile. Need to figure out how to upgrade to 3.1.0 and later. Spoke with Tri and he is going to be taking a look. Note: compiling with clang currently errors for the cute headers.
- [x] Update test exercise above codepath
- [x] Still need to disable on seq_len % 128 != 0 for backward( Tri beat me to it a4f148b6ab)
- [x] Add determinism warning to BWD, Tri got to this one as well: 1c41d2b
- [x] Update dispatcher to universally prefer FlashV2
- [x] Update tests to exercise new head_dims
- [x] Move the head_dim padding from kernel to top level composite implicit function in order to make it purely functional
- [x] Create template generator script
- [x] Initial cmake support for building kernels/ folder
- [x] Replay CudaGraph changes
### Results
#### Forward only
The TFlops are reported here are on a100 that is underclocked.

#### Forward+Backward
Ran a sweep and for large compute bound sizes we do see a ~2x performance increase for forw+back.
<img width="1684" alt="Screenshot 2023-07-20 at 3 47 47 PM" src="https://github.com/pytorch/pytorch/assets/32754868/fdd26e07-0077-4878-a417-f3a418b6fb3b">
Pull Request resolved: https://github.com/pytorch/pytorch/pull/105602
Approved by: https://github.com/huydhn, https://github.com/cpuhrsch
This PR introduces record and replay functionality for `ShapeEnv` instances. In short,
throughout the execution of a program, we record events (e.g. function calls that modify
its state) so that, in the future, we are able to reproduce any intermediary state of the
instance.
In summary, this PR introduces the following changes (they mostly belong to
_symbolic_shapes.py_ unless otherwise stated):
- Create `ShapeEnvEvent` class for recording function calls + arguments
- Create `record_shapeenv_event` decorator and decorate every function that changes the
state of a `ShapeEnv`: it creates an appropriate event and add it to the available
ShapeEnv instance (sometimes it has to extract from `SymTypes`).
- Create `SymNode.with_shape_env` convenient function for replacing `ShapeEnv` references
- Wraps `ShapeEnv` initialization method: so that we also save the exact way a `ShapeEnv`
was constructed, i.e. arguments
- Introduces a way to compare two `ShapeEnv` instances, defining a concept of state for
that class. In short, the state of `ShapeEnv` is every variable that may change the
execution flow
- Create `check_shape_env_recorded_events` dynamo configuration for enabling the check for
equality the state of `ShapeEnv` with another one that was constructed by replaying all
the recorded events. This check takes place inside `produce_guards`
- Create `replay_shape_env_events` function for replaying given events. It assumes the
first event is `ShapeEnv` initialization function
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107989
Approved by: https://github.com/ezyang
This combines a bunch of python global state guards into a single C++ guard and switches to checking them 100% of the time. It also adds a few new guards for things that change inductor's behavior. Even though we are checking more things, I expect this to be much faster.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108624
Approved by: https://github.com/anijain2305
**Motivation:**
We try to make torch.cond use torch.compile automatically so that we could error out when there is side-effects in the branches and correctly handle the closures.
Before this PR, we have a warning if we don't turn on a config raise_on_backend_change (turning it on gives us an error) for the following code:
```python
def foo()
# Inside torch.cond, we'd like to do something like
torch.compile(foo, backend="eager", fullgraph=True)(...)
...
# Users may then call torch.compile somewhere else.
# Dynamo will use the cached code of foo for "eager" backend
# but we expect dynamo to recompile with "inductor" backend.
torch.compile(foo, backend="inductor")(...)
```
This PR adds a BACKEND_MATCH guard. Effectively, it implements a per-backend cache. In the above example, the cached code for "eager" won't work for "inductor" due to guard check failures and the second torch.compile will do a re-compilation. In the future, it might be useful to have something like a configuration guard that guards against dynamo configuration changes across different compiles (e.g. compile a function with fullgraph=False then compile it again with fullgraph=True).
**Implementation:**
1. We add a guarded_backend_cache and check the most_recent_backend against the backend associated with cached code. We also remove the raise_on_backend_change flag.
2. Then newly added context manager and guard adds more lines for debug log so we change the uppper limit from 50 to 55.
**Test Plan:**
Removed original tests that raise on different backend and add a new test to test whether the BACKEND_MATCH guard can guard against backend change.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107337
Approved by: https://github.com/jansel