Starts addressing https://github.com/pytorch/pytorch/issues/97712 by
- Minimizing intermediates usage for foreach Adam
- Document the extra memory usage
- Add comments within the code for clarity now that we reuse intermediates
- Add tests
- Did some refactoring
Next steps involve doing this for all other foreach implementations. Note that even after this change, foreach mem usage will be higher than forloop due to the fact that we have a minimum budget of 1 intermediate (to not muddle the input values) and the intermediate will be larger. For capturable, the memory usage is higher due to moving more tensors to CUDA.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/104780
Approved by: https://github.com/albanD
This is a reland of https://github.com/pytorch/pytorch/pull/100007 with a build fix for Windows debug builds.
`at::native::ParamsHash` only works on structs with standard layout, but `std::string` isn't one in Visual C++ debug builds, which one can easily verified by running something like:
```cpp
#define _DEBUG
#include <type_traits>
#include <string>
static_assert(std::is_standard_layout_v<std::string>, "Oh noes");
```
If above conditon is not met, instead of printing a static_assert output, VC++ raises a very cryptic compilation errors, see https://github.com/pytorch/pytorch/pull/100007#discussion_r1227116292 for more detail.
Also, using `std::hash` for string should result in a faster hash function.
(cherry picked from commit 74b7a6c75e)
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### <samp>🤖 Generated by Copilot at 5914771</samp>
This pull request introduces a new function `_group_tensors_by_device_and_dtype` that can group tensors by their device and dtype, and updates the `foreach` utilities and several optimizers to use this function. The goal is to improve the performance, readability, and compatibility of the code that handles tensors with different properties. The pull request also adds a test case and type annotations for the new function, and some error checks for the `fused` argument in Adam and AdamW.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/103912
Approved by: https://github.com/janeyx99
Big OOP correction continued. Also added a test this time to verify the defaulting was as expected.
The key here is realizing that the grouping for foreach already assumes that the non-param tensorlists follow suit in dtype and device, so it is too narrow to check that _all_ tensors were on CUDA. The main leeway this allowed was state_steps, which are sometimes cpu tensors. Since foreach _can_ handle cpu tensors, this should not introduce breakage.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/95820
Approved by: https://github.com/albanD
Rolling back the default change for Adam and rectifying the docs to reflect that AdamW never defaulted to fused.
Since our fused implementations are relatively newer, let's give them a longer bake-in time before flipping the switch for every user.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/95241
Approved by: https://github.com/ngimel
This allows it so that ONLY when the users don't set anything for foreach or fused do we switch the default and cascades adam so that we default to fused, then foreach, then single-tensor.
To clarify:
* if the user puts True in foreach _only_, it will run the foreach implementation.
* if the user puts True in fused _only_, it will run the fused implementation.
* if the user puts True in foreach AND for fused, it will run the fused implementation.
And:
* if the user puts False in foreach _only_, it will run the single tensor implementation.
* if the user puts False in fused _only_, it will still run the single tensor implementation.
* if the user puts False in foreach AND for fused, it will run the single tensor implementation.
I also didn't trust myself that much with the helper function, so I ran some local asserts on _default_to_fused_or_foreach. The only point left to really test is the type(p) -- torch.Tensor but I think the distributed tests will catch that in CI.
```
cuda_only_fp_list = [
torch.rand((1, 2), device="cuda", dtype=torch.float32),
torch.rand((1, 2), device="cuda", dtype=torch.float64),
torch.rand((1, 2), device="cuda", dtype=torch.float16),
torch.rand((1, 2), device="cuda", dtype=torch.bfloat16),
]
cuda_only_int_list = [
torch.randint(1024, (1, 2), device="cuda", dtype=torch.int64),
]
cpu_list = [
torch.rand((1, 2), device="cpu", dtype=torch.float32),
torch.rand((1, 2), device="cpu", dtype=torch.float64),
torch.rand((1, 2), device="cpu", dtype=torch.float16),
]
none_list = [None]
# differentiable should always make it return false for both
assert _default_to_fused_or_foreach([cuda_only_fp_list], True, True) == (False, False)
assert _default_to_fused_or_foreach([cuda_only_fp_list], True, False) == (False, False)
# cpu lists should always make it return false for both
assert _default_to_fused_or_foreach([cuda_only_fp_list, cpu_list], False, True) == (False, False)
assert _default_to_fused_or_foreach([cpu_list], False, True) == (False, False)
assert _default_to_fused_or_foreach([cuda_only_fp_list, cpu_list], False, False) == (False, False)
assert _default_to_fused_or_foreach([cpu_list], False, False) == (False, False)
# has fused triggers correctly
assert _default_to_fused_or_foreach([cuda_only_fp_list], False, True) == (True, False)
assert _default_to_fused_or_foreach([cuda_only_fp_list], False, False) == (False, True)
# ints always goes to foreach
assert _default_to_fused_or_foreach([cuda_only_fp_list, cuda_only_int_list], False, True) == (False, True)
assert _default_to_fused_or_foreach([cuda_only_fp_list, cuda_only_int_list], False, False) == (False, True)
# Nones don't error
assert _default_to_fused_or_foreach([cuda_only_fp_list, none_list], False, True) == (True, False)
assert _default_to_fused_or_foreach([cuda_only_fp_list, cuda_only_int_list, none_list], False, True) == (False, True)
assert _default_to_fused_or_foreach([none_list], False, True) == (True, False)
assert _default_to_fused_or_foreach([none_list], False, False) == (False, True)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/93184
Approved by: https://github.com/albanD
Attempts to fix#92656
BC-breaking! This changes the default of zero_grad in optim and in nn to default set grads to None instead of zero tensors. We are changing the default because there are proven perf wins and existing code has typically not regressed due to this change. (will probably have to flesh out this note more).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92731
Approved by: https://github.com/ngimel
@mlazos: skips `item()` calls if compiling with dynamo, by defining a helper function `_get_value` which either returns the result of `.item()` or the scalar cpu tensor if compiling with dynamo. This was done because removing `item()` calls significantly regresses eager perf. Additionally, `_dispatch_sqrt` calls the appropriate sqrt function (math.sqrt, or torch.sqrt).
Fixes https://github.com/pytorch/torchdynamo/issues/1083
This PR will no longer be needed once symint support is default.
This PR closes all remaining graph breaks in the optimizers (!!)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/88173
Approved by: https://github.com/albanD
### Description
Across PyTorch's docstrings, both `callable` and `Callable` for variable types. The Callable should be capitalized as we are referring to the `Callable` type, and not the Python `callable()` function.
### Testing
There shouldn't be any testing required.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/82487
Approved by: https://github.com/albanD
Adds the `differentiable` argument, a method for updating parameters in an existing optimizer, and a template for testing the differentiability of multiple optimizers.
This is all based in discussions with @albanD & @jbschlosser
Pull Request resolved: https://github.com/pytorch/pytorch/pull/80938
Approved by: https://github.com/albanD
Near term fix for https://github.com/pytorch/pytorch/issues/76368.
Q. Why does the user need to request `capturable=True` in the optimizer constructor? Why can't capture safety be completely automatic?
A. We need to set up capture-safe (device-side) state variables before capture. If we don't, and step() internally detects capture is underway, it's too late: the best we could do is create a device state variable and copy the current CPU value into it, which is not something we want baked into the graph.
Q. Ok, why not just do the capture-safe approach with device-side state variables all the time?
A. It incurs several more kernel launches per parameter, which could really add up and regress cpu overhead for ungraphed step()s. If the optimizer won't be captured, we should allow step() to stick with its current cpu-side state handling.
Q. But cuda RNG is a stateful thing that maintains its state on the cpu outside of capture and replay, and we capture it automatically. Why can't we do the same thing here?
A. The graph object can handle RNG generator increments because its capture_begin, capture_end, and replay() methods can see and access generator object. But the graph object has no explicit knowledge of or access to optimizer steps in its capture scope. We could let the user tell the graph object what optimizers will be stepped in its scope, ie something like
```python
graph.will_use_optimizer(opt)
graph.capture_begin()
...
```
but that seems clunkier than an optimizer constructor arg.
I'm open to other ideas, but right now I think constructor arg is necessary and the least bad approach.
Long term, https://github.com/pytorch/pytorch/issues/71274 is a better fix.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77862
Approved by: https://github.com/ezyang
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69936
Currently, the optimizers in `torch/optim/_multi_tensor/` all override the base Optimizer class' implementation of `zero_grad` with the same foreach zero_grad implementation (e.g. [here](https://github.com/pytorch/pytorch/blob/master/torch/optim/_multi_tensor/adadelta.py#L93-L114)). There is a TODO that indicates that this should be refactored to the base class once the foreach ops are in good shape. This PR is intended to address that TODO.
Test Plan: Imported from OSS
Reviewed By: mrshenli
Differential Revision: D33346748
Pulled By: mikaylagawarecki
fbshipit-source-id: 6573f4776aeac757b6a778894681868191a1b4c7
Summary:
Fixes https://github.com/pytorch/pytorch/issues/46480 -- for SGD.
## Notes:
- I have modified the existing tests to take a new `constructor_accepts_maximize` flag. When this is set to true, the ` _test_basic_cases_template` function will test both maximizing and minimizing the sample function.
- This was the clearest way I could think of testing the changes -- I would appreciate feedback on this strategy.
## Work to be done:
[] I need to update the docs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67847
Reviewed By: H-Huang
Differential Revision: D32252631
Pulled By: albanD
fbshipit-source-id: 27915a3cc2d18b7e4d17bfc2d666fe7d2cfdf9a4
