On par with `CUDA` implementation.
For `autocast` logic, same with `CUDA` + `Fused Adam`:
- check inf in `gradscalar.step`
- In fused kernel, if there is `inf`, do nothing. If not, unscale the grad ( also write back) and update the param.
**TestPlan**:
```
# extend CUDA only test for CPU fused adagrad
python test_optim.py -k test_fused_matches_forloop
python test_optim.py -k test_fused_large_tensor
python test_torch.py -k test_grad_scaling_autocast_fused
# extend fused test
python test_torch.py -k test_params_invalidated_with_grads_invalidated_between_unscale_and_step
python test_optim.py -k test_can_load_older_state_dict
# newly added test (follow 6b1f13ea2f/test/test_cuda.py (L1108))
python test_optim.py -k test_grad_scaling_autocast_fused_optimizers
```
**Benchmark**:
**5.1x** on 56 core SPR
**Parameter-size=1M**
**Nparams=10**
[test script](https://gist.github.com/zhuhaozhe/ef9a290ad3f8f4067b3373a3bdaa33e7)
```
numactl -C 0-55 -m 0 python bench_adam.py
non-fused 6.0174267292022705 s
fused 1.1787631511688232 s
```
**Note: Fused kernel accuracy**
The accuracy failure in CI shows a little higher than default tolerance
```
2024-04-02T06:09:16.2213887Z Mismatched elements: 21 / 64 (32.8%)
2024-04-02T06:09:16.2214339Z Greatest absolute difference: 1.5735626220703125e-05 at index (6, 6) (up to 1e-05 allowed)
2024-04-02T06:09:16.2214813Z Greatest relative difference: 1.0073336852656212e-05 at index (4, 1) (up to 1.3e-06 allowed)
```
I have debug it step by step and unfortunately we may not able to make the `fused kernel` exactly same with `non fused` one due to compiler optimizations.
For example, in non-fused impl
```
exp_avg_sq.mul_(beta2).addcmul_(grad, grad.conj(), value=1 - beta2)
```
and in fused impl
```
exp_avg_sq_ptr[d] = scalar_t(beta2) * exp_avg_sq_ptr[d];
// std::cout << "exp_avg_sq " << exp_avg_sq_ptr[d] << std::endl;
exp_avg_sq_ptr[d] = exp_avg_sq_ptr[d] +
scalar_t(exp_avg_sq_grad_coefficient) * grad_val * grad_val;
```
If I keep `std::cout`, I can get exactly same results in UT
```
===============param
0.6796758770942688
0.6796758770942688
```
But when I comment out it, there will be a difference
```
===============param
0.6796758770942688
0.6796759366989136
```
So I will make the tolerance a little higher than default one.
Co-authored-by: Jane Xu <janeyx@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/123074
Approved by: https://github.com/jgong5, https://github.com/janeyx99
MTIA device has its own Module in PyTorch now.
torch.mtia has following APIs similar to other backends. The lazy_init is also supported.
```
__all__ = [
"init",
"is_available",
"synchronize",
"device_count",
"current_device",
"current_stream",
"default_stream",
"set_stream",
"stream",
"device",
]
```
------------
For device management. We expand AccleratorHooksInterface to support generic device management and it can be used in both C++ and PyThon.
```
def _accelerator_hooks_device_count() -> _int: ...
def _accelerator_hooks_set_current_device(device_index: _int) -> None: ...
def _accelerator_hooks_get_current_device() -> _int : ...
def _accelerator_hooks_exchange_device(device_index: _int) -> _int : ...
def _accelerator_hooks_maybe_exchange_device(device_index: _int) -> _int : ...
```
---------
Adding get_device_module API to retrieve device modules for different device types.
```
def get_device_module(device: Optional[Union[torch.device, str]] = None)
```
---------
@exported-using-ghexport
Differential Revision: [D52923602](https://our.internmc.facebook.com/intern/diff/D52923602/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/123612
Approved by: https://github.com/albanD
ghstack dependencies: #123611
This diff intends to build device generic torch.Stream and torch.Event for newly added accelerators in PyTorch.
------------
**torch.Stream APIs**
```
# Defined in torch/csrc/Stream.cpp
class Stream(_StreamBase):
stream_id: _int # Stream id
device_index: _int
device_type: _int
device: _device # The device of the stream
@overload
def __new__(self, device: Optional[DeviceLikeType] = None, priority: _int = 0) -> Stream: ...
@overload
def __new__(self, stream_id: _int, device_index: _int, device_type: _int, priority: _int = 0) -> Stream: ...
def query(self) -> _bool: ...
def synchronize(self) -> None: ...
def wait_event(self, event: Event) -> None: ...
def wait_stream(self, other: Stream) -> None: ...
def record_event(self, event: Optional[Event] = None) -> Event: ...
def query(self) -> None: ...
def synchronize(self) -> None: ...
def __hash__(self) -> _int: ...
def __repr__(self) -> str: ...
def __eq__(self, other: object) -> _bool: ...
```
------------------
**torch.Event APIs**:
- IPC related APIs are not implemented, since many device backends don't support it, but we leave interfaces there for future adaption of torch.cuda.Stream.
- currently only the enable_timing is supported, since it is the most common one used in other device backends. We have to refactor the event flag system in PyTorch to support more fancy flag.
- elapsedTime API is added to c10::Event
```
# Defined in torch/csrc/Event.cpp
class Event(_EventBase):
device: _device # The device of the Event
event_id: _int # The raw event created by device backend
def __new__(self,
device: Optional[DeviceLikeType] = None,
enable_timing: _bool = False,
blocking: _bool = False,
interprocess: _bool = False) -> Event: ...
@classmethod
def from_ipc_handle(self, device: DeviceLikeType, ipc_handle: bytes) -> Event: ...
def record(self, stream: Optional[Stream] = None) -> None: ...
def wait(self, stream: Optional[Stream] = None) -> None: ...
def query(self) -> _bool: ...
def elapsed_time(self, other: Event) -> _float: ...
def synchronize(self) -> None: ...
def ipc_handle(self) -> bytes: ...
def __repr__(self) -> str: ...
```
-----------
c10::Event provides new APIs
- calculate **elapsedTime**.
- Get raw event id
- Synchronize event.
```
double elapsedTime(const Event& event) const {
return impl_.elapsedTime(event.impl_);
}
void* eventId() const {
return impl_.eventId();
}
void synchronize() const {
return impl_.synchronize();
}
```
----------
TODO: need to find a good way to test them in PyTorch with API mocks.
Differential Revision: [D55351839](https://our.internmc.facebook.com/intern/diff/D55351839/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/123611
Approved by: https://github.com/albanD
VariableInfo is used by both `custom_function.h` (in a templated class) and `compiled_autograd.h` (in a class with some templated methods). Another way could have been to make a `compiled_autograd.cpp` and forward declare VariableInfo, but this VariableInfo was also being used in other nodes like PyNode so it felt cleaner to do it this way.
Differential Revision: [D54287007](https://our.internmc.facebook.com/intern/diff/D54287007)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120732
Approved by: https://github.com/jansel
# Motivation
As mentioned in [[RFC] Intel GPU Runtime Upstreaming](https://github.com/pytorch/pytorch/issues/114842), the next runtime component we would like to upstream is `Event` which handles the status of an operation that is being executed. Typically, in some circumstances, we can fine-grain control of the operation execution via `Event`.
# Design
`XPUEvent` is a movable but not a copyable wrapper around sycl event. It should be created lazily on an XPU device when recording an `XPUStream`. Meanwhile, `XPUEvent` can wait for another `XPUEvent` or all the submitted kernels on an `XPUStream` to complete. Align to the other backend, the C++ files related to `Event` will be placed in `aten/src/ATen/xpu` folder. For frontend code, `XPUEvent` runtime API will be bound to Python `torch.xpu.Event`. The corresponding C++ code will be placed in `torch/csrc/xpu/Event.cpp` and Python code will be placed in `torch/xpu/streams.py` respectively.
# Additional Context
It is worth mentioning that the `elapsed_time` method is temporarily not supported by `XPUEvent`. We will be adding support for it soon. Meanwhile `XPUEvent` doesn't support IPC from different processes. For the other parts, we have almost a 1:1 mapping with CUDA.
lack of the below APIs:
- `torch.cuda.Event.ipc_handle`
- `CUDAEvent`'s constructor with `IpcEventHandle`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/117734
Approved by: https://github.com/EikanWang, https://github.com/gujinghui, https://github.com/jgong5, https://github.com/malfet
ghstack dependencies: #117611, #117619
Replaces `view_func()` closures with a reified `ViewFunc` data structure. Codegen generates a `ViewFunc` subclass for each view op (e.g. `NarrowViewFunc`) containing state needed to reconstruct the view. The `ViewFunc` API allows for querying and hot-swapping any `SymInt`s or `Tensors` in the state through `get_symints()` / `get_tensors()` / `clone_and_set()`, which will be essential for fake-ification later on.
```cpp
/// Base class for view functions, providing reapplication of a view on a new base.
/// Each view op should get a codegenerated subclass of this class containing
/// any state needed to reconstruct the view. The class also provides convenience
/// accessors for saved SymInts / tensor state. This is useful for e.g. fake-ification,
/// where we want to use symbolic values or fake tensors instead.
struct TORCH_API ViewFunc {
virtual ~ViewFunc() {}
/// Returns any SymInts in the saved state.
virtual std::vector<c10::SymInt> get_symints() const { return {}; }
/// Returns the number of SymInts in the saved state.
virtual size_t num_symints() const { return 0; }
/// Returns any tensors in the saved state.
virtual std::vector<at::Tensor> get_tensors() const { return {}; }
/// Returns the number of tensors in the saved state.
virtual size_t num_tensors() const { return 0; }
/// Reapplies the view on the given base using the saved state.
virtual at::Tensor operator()(const at::Tensor&) const = 0;
/// Returns a clone of this ViewFunc, optionally with the specified saved state.
virtual std::unique_ptr<ViewFunc> clone_and_set(
std::optional<std::vector<c10::SymInt>> = c10::nullopt,
std::optional<std::vector<at::Tensor>> = c10::nullopt) const = 0;
protected:
/// Sets the values of any SymInts in the saved state. The input vector size must
/// match the number of SymInts in the saved state (i.e. the size of the list
/// returned by get_symints()).
virtual void set_symints(std::vector<c10::SymInt>) {}
/// Sets the values of any Tensors in the saved state. The input vector size must
/// match the number of Tensors in the saved state (i.e. the size of the list
/// returned by get_tensors()).
virtual void set_tensors(std::vector<at::Tensor>) {}
};
```
New codegen files:
* `torch/csrc/autograd/generated/ViewFunc.h`
* `torch/csrc/autograd/generated/ViewFuncs.cpp`
The templates for these also contains impls for `ChainedViewFunc` and `ErroringViewFunc` which are used in a few places within autograd.
Example codegen for `slice.Tensor`:
```cpp
// torch/csrc/autograd/generated/ViewFuncs.h
#define SLICE_TENSOR_VIEW_FUNC_AVAILABLE
struct SliceTensorViewFunc : public torch::autograd::ViewFunc {
SliceTensorViewFunc(int64_t dim, c10::optional<c10::SymInt> start, c10::optional<c10::SymInt> end, c10::SymInt step) : dim(dim), start(start), end(end), step(step)
{};
virtual ~SliceTensorViewFunc() override {};
virtual std::vector<c10::SymInt> get_symints() const override;
virtual size_t num_symints() const override;
virtual std::vector<at::Tensor> get_tensors() const override;
virtual size_t num_tensors() const override;
virtual at::Tensor operator()(const at::Tensor&) const override;
virtual std::unique_ptr<ViewFunc> clone_and_set(
std::optional<std::vector<c10::SymInt>> = c10::nullopt,
std::optional<std::vector<at::Tensor>> = c10::nullopt) const override;
protected:
virtual void set_symints(std::vector<c10::SymInt>) override;
virtual void set_tensors(std::vector<at::Tensor>) override;
private:
int64_t dim;
c10::optional<c10::SymInt> start;
c10::optional<c10::SymInt> end;
c10::SymInt step;
};
...
// torch/csrc/autograd/generated/ViewFuncs.cpp
std::vector<c10::SymInt> SliceTensorViewFunc::get_symints() const {
::std::vector<c10::SymInt> symints;
symints.reserve((start.has_value() ? 1 : 0) + (end.has_value() ? 1 : 0) + 1);
if(start.has_value()) symints.insert(symints.end(), *(start));
if(end.has_value()) symints.insert(symints.end(), *(end));
symints.push_back(step);
return symints;
}
size_t SliceTensorViewFunc::num_symints() const {
return static_cast<size_t>((start.has_value() ? 1 : 0) + (end.has_value() ? 1 : 0) + 1);
}
void SliceTensorViewFunc::set_symints(std::vector<c10::SymInt> symints) {
TORCH_INTERNAL_ASSERT(symints.size() == num_symints());
auto i = 0;
if(start.has_value()) start = symints[i];
i += (start.has_value() ? 1 : 0);
if(end.has_value()) end = symints[i];
i += (end.has_value() ? 1 : 0);
step = symints[i];
}
std::vector<at::Tensor> SliceTensorViewFunc::get_tensors() const {
::std::vector<at::Tensor> tensors;
return tensors;
}
size_t SliceTensorViewFunc::num_tensors() const {
return static_cast<size_t>(0);
}
void SliceTensorViewFunc::set_tensors(std::vector<at::Tensor> tensors) {
TORCH_INTERNAL_ASSERT(tensors.size() == num_tensors());
}
at::Tensor SliceTensorViewFunc::operator()(const at::Tensor& input_base) const {
return at::_ops::slice_Tensor::call(input_base, dim, start, end, step);
}
std::unique_ptr<ViewFunc> SliceTensorViewFunc::clone_and_set(
std::optional<std::vector<c10::SymInt>> symints,
std::optional<std::vector<at::Tensor>> tensors) const {
auto output = std::make_unique<SliceTensorViewFunc>(dim, start, end, step);
if (symints.has_value()) {
output->set_symints(std::move(*(symints)));
}
if (tensors.has_value()) {
output->set_tensors(std::move(*(tensors)));
}
return output;
}
```
The `_view_func()` / `_view_func_unsafe()` methods now accept two additional (optional) args for `symint_visitor_fn` / `tensor_visitor_fn`. If these are defined, they are expected to be python callables that operate on a single SymInt / tensor and return a new one. This allows for the hot-swapping needed during fake-ification.
For testing, there are extensive pre-existing tests, and I added a test to ensure that hot-swapping functions correctly.
```sh
python test/test_autograd.py -k test_view_func_replay
python test/test_ops.py -k test_view_replay
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118404
Approved by: https://github.com/ezyang
Some operations, such as GEMMs, could be implemented using more than one library or more than one technique. For example, a GEMM could be implemented for CUDA or ROCm using either the blas or blasLt libraries. Further, ROCm's rocblas and hipblaslt libraries allow the user to query for all possible algorithms and then choose one. How does one know which implementation is the fastest and should be chosen? That's what TunableOp provides.
See the README.md for additional details.
TunableOp was ported from onnxruntime starting from commit 08dce54266. The content was significantly modified and reorganized for use within PyTorch. The files copied and their approximate new names or source content location within aten/src/ATen/cuda/tunable include the following:
- onnxruntime/core/framework/tunable.h -> Tunable.h
- onnxruntime/core/framework/tuning_context.h -> Tunable.h
- onnxruntime/core/framework/tuning_context_impl.h -> Tunable.cpp
- onnxruntime/core/providers/rocm/tunable/gemm_common.h -> GemmCommon.h
- onnxruntime/core/providers/rocm/tunable/gemm_hipblaslt.h -> GemmHipblaslt.h
- onnxruntime/core/providers/rocm/tunable/gemm_rocblas.h -> GemmRocblas.h
- onnxruntime/core/providers/rocm/tunable/gemm_tunable.cuh -> TunableGemm.h
- onnxruntime/core/providers/rocm/tunable/rocm_tuning_context.cc -> Tunable.cpp
- onnxruntime/core/providers/rocm/tunable/util.h -> StreamTimer.h
- onnxruntime/core/providers/rocm/tunable/util.cc -> StreamTimer.cpp
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114894
Approved by: https://github.com/xw285cornell, https://github.com/jianyuh
# Motivation
According to [[1/2] Intel GPU Runtime Upstreaming for Stream](https://github.com/pytorch/pytorch/pull/117611), as mentioned in [[RFC] Intel GPU Runtime Upstreaming](https://github.com/pytorch/pytorch/issues/114842), the second PR covers the changes under `python frontend`.
# Design
Currently, it primarily offers stream-related APIs, including
- `torch.xpu.StreamContext`
- `torch.xpu.current_stream`
- `torch.xpu.set_stream`
- `torch.xpu.synchronize`
- `torch._C._xpu_getCurrentRawStream`
# Additional Context
We will implement functions like `torch.xpu.Stream.wait_event`, `torch.xpu.Stream.wait_stream`, and `torch.xpu.Stream.record_event` in the next PR related with `Event`.
The differences with CUDA:
no default and external stream in XPU and lack of below APIs:
- `torch.cuda.ExternalStream`
- `torch.cuda.default_stream`
- `toch.cuda.is_current_stream_capturing`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/117619
Approved by: https://github.com/EikanWang, https://github.com/jgong5, https://github.com/gujinghui, https://github.com/albanD
ghstack dependencies: #117611
Replaces `view_func()` closures with a reified `ViewFunc` data structure. Codegen generates a `ViewFunc` subclass for each view op (e.g. `NarrowViewFunc`) containing state needed to reconstruct the view. The `ViewFunc` API allows for querying and hot-swapping any `SymInt`s or `Tensors` in the state through `get_symints()` / `get_tensors()` / `clone_and_set()`, which will be essential for fake-ification later on.
```cpp
/// Base class for view functions, providing reapplication of a view on a new base.
/// Each view op should get a codegenerated subclass of this class containing
/// any state needed to reconstruct the view. The class also provides convenience
/// accessors for saved SymInts / tensor state. This is useful for e.g. fake-ification,
/// where we want to use symbolic values or fake tensors instead.
struct TORCH_API ViewFunc {
virtual ~ViewFunc() {}
/// Returns any SymInts in the saved state.
virtual std::vector<c10::SymInt> get_symints() const { return {}; }
/// Returns the number of SymInts in the saved state.
virtual size_t num_symints() const { return 0; }
/// Returns any tensors in the saved state.
virtual std::vector<at::Tensor> get_tensors() const { return {}; }
/// Returns the number of tensors in the saved state.
virtual size_t num_tensors() const { return 0; }
/// Reapplies the view on the given base using the saved state.
virtual at::Tensor operator()(const at::Tensor&) const = 0;
/// Returns a clone of this ViewFunc, optionally with the specified saved state.
virtual std::unique_ptr<ViewFunc> clone_and_set(
std::optional<std::vector<c10::SymInt>> = c10::nullopt,
std::optional<std::vector<at::Tensor>> = c10::nullopt) const = 0;
protected:
/// Sets the values of any SymInts in the saved state. The input vector size must
/// match the number of SymInts in the saved state (i.e. the size of the list
/// returned by get_symints()).
virtual void set_symints(std::vector<c10::SymInt>) {}
/// Sets the values of any Tensors in the saved state. The input vector size must
/// match the number of Tensors in the saved state (i.e. the size of the list
/// returned by get_tensors()).
virtual void set_tensors(std::vector<at::Tensor>) {}
};
```
New codegen files:
* `torch/csrc/autograd/generated/ViewFunc.h`
* `torch/csrc/autograd/generated/ViewFuncs.cpp`
The templates for these also contains impls for `ChainedViewFunc` and `ErroringViewFunc` which are used in a few places within autograd.
Example codegen for `slice.Tensor`:
```cpp
// torch/csrc/autograd/generated/ViewFuncs.h
#define SLICE_TENSOR_VIEW_FUNC_AVAILABLE
struct SliceTensorViewFunc : public torch::autograd::ViewFunc {
SliceTensorViewFunc(int64_t dim, c10::optional<c10::SymInt> start, c10::optional<c10::SymInt> end, c10::SymInt step) : dim(dim), start(start), end(end), step(step)
{};
virtual ~SliceTensorViewFunc() override {};
virtual std::vector<c10::SymInt> get_symints() const override;
virtual size_t num_symints() const override;
virtual std::vector<at::Tensor> get_tensors() const override;
virtual size_t num_tensors() const override;
virtual at::Tensor operator()(const at::Tensor&) const override;
virtual std::unique_ptr<ViewFunc> clone_and_set(
std::optional<std::vector<c10::SymInt>> = c10::nullopt,
std::optional<std::vector<at::Tensor>> = c10::nullopt) const override;
protected:
virtual void set_symints(std::vector<c10::SymInt>) override;
virtual void set_tensors(std::vector<at::Tensor>) override;
private:
int64_t dim;
c10::optional<c10::SymInt> start;
c10::optional<c10::SymInt> end;
c10::SymInt step;
};
...
// torch/csrc/autograd/generated/ViewFuncs.cpp
std::vector<c10::SymInt> SliceTensorViewFunc::get_symints() const {
::std::vector<c10::SymInt> symints;
symints.reserve((start.has_value() ? 1 : 0) + (end.has_value() ? 1 : 0) + 1);
if(start.has_value()) symints.insert(symints.end(), *(start));
if(end.has_value()) symints.insert(symints.end(), *(end));
symints.push_back(step);
return symints;
}
size_t SliceTensorViewFunc::num_symints() const {
return static_cast<size_t>((start.has_value() ? 1 : 0) + (end.has_value() ? 1 : 0) + 1);
}
void SliceTensorViewFunc::set_symints(std::vector<c10::SymInt> symints) {
TORCH_INTERNAL_ASSERT(symints.size() == num_symints());
auto i = 0;
if(start.has_value()) start = symints[i];
i += (start.has_value() ? 1 : 0);
if(end.has_value()) end = symints[i];
i += (end.has_value() ? 1 : 0);
step = symints[i];
}
std::vector<at::Tensor> SliceTensorViewFunc::get_tensors() const {
::std::vector<at::Tensor> tensors;
return tensors;
}
size_t SliceTensorViewFunc::num_tensors() const {
return static_cast<size_t>(0);
}
void SliceTensorViewFunc::set_tensors(std::vector<at::Tensor> tensors) {
TORCH_INTERNAL_ASSERT(tensors.size() == num_tensors());
}
at::Tensor SliceTensorViewFunc::operator()(const at::Tensor& input_base) const {
return at::_ops::slice_Tensor::call(input_base, dim, start, end, step);
}
std::unique_ptr<ViewFunc> SliceTensorViewFunc::clone_and_set(
std::optional<std::vector<c10::SymInt>> symints,
std::optional<std::vector<at::Tensor>> tensors) const {
auto output = std::make_unique<SliceTensorViewFunc>(dim, start, end, step);
if (symints.has_value()) {
output->set_symints(std::move(*(symints)));
}
if (tensors.has_value()) {
output->set_tensors(std::move(*(tensors)));
}
return output;
}
```
The `_view_func()` / `_view_func_unsafe()` methods now accept two additional (optional) args for `symint_visitor_fn` / `tensor_visitor_fn`. If these are defined, they are expected to be python callables that operate on a single SymInt / tensor and return a new one. This allows for the hot-swapping needed during fake-ification.
For testing, there are extensive pre-existing tests, and I added a test to ensure that hot-swapping functions correctly.
```sh
python test/test_autograd.py -k test_view_func_replay
python test/test_ops.py -k test_view_replay
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118404
Approved by: https://github.com/ezyang
# Motivation
This PR intends to extend `cuda_lazy_init` to `device_lazy_init` which is a device-agnostic API that can support any backend. And change `maybe_initialize_cuda` to `maybe_initialize_device` to support lazy initialization for CUDA while maintaining scalability.
# Design
We maintain a flag for each backend to manage the lazy initialization state separately.
# Additional Context
No need more UTs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118846
Approved by: https://github.com/malfet
# Motivation
According to [[1/4] Intel GPU Runtime Upstreaming for Device](https://github.com/pytorch/pytorch/pull/116019), As mentioned in [[RFC] Intel GPU Runtime Upstreaming](https://github.com/pytorch/pytorch/issues/114842), this third PR covers the changes under `libtorch_python`.
# Design
This PR primarily offers device-related APIs in python frontend, including
- `torch.xpu.is_available`
- `torch.xpu.device_count`
- `torch.xpu.current_device`
- `torch.xpu.set_device`
- `torch.xpu.device`
- `torch.xpu.device_of`
- `torch.xpu.get_device_name`
- `torch.xpu.get_device_capability`
- `torch.xpu.get_device_properties`
- ====================
- `torch.xpu._DeviceGuard`
- `torch.xpu._is_compiled`
- `torch.xpu._get_device`
# Additional Context
We will implement the support of lazy initialization in the next PR.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/116850
Approved by: https://github.com/EikanWang, https://github.com/jgong5, https://github.com/gujinghui, https://github.com/malfet
Summary: Now we can allocate an AOTIModelContainerRunner object instead of relying on torch.utils.cpp_extension.load_inline. Also renamed AOTInductorModelRunner to AOTIRunnerUtil in this PR.
Test Plan: CI
Reviewed By: khabinov
Differential Revision: D52339116
Pull Request resolved: https://github.com/pytorch/pytorch/pull/116269
Approved by: https://github.com/khabinov
## Summary
This PR added 3 intra-node GPU allreduce algorithms to PyTorch:
- One-shot allreduce (inspired by FasterTransformer): all ranks simultaneously read and accumulate data from other ranks.
- Two-shot allreduce (inspired by FasterTransformer): all ranks simultanesouly read and accumulate `1 / world_size` data from other ranks. Then all ranks read accumulated data from other ranks. (effectively one-shot reduce-scatter + one-shot all-gather).
- Hybrid cube mesh allreduce (original): a one-shot allreduce variant that avoids transmission over PCIe on HCM topology.
## Micro Benchmarks



## Details
The intra-node algos are organized behind `c10d::IntraNodeComm`, which is responsible for:
- Managing handshaking and cuda IPC handle exchange among ranks.
- Querying NVLink connection and detecting topology.
- Performing algo selection based on available info.
- Launching the selected allreduce kernel.
`c10d::IntraNodeComm` is integrated into `c10d::ProcessGroupNCCL` as follows:
- When the `ENABLE_INTRA_NODE_COMM` environment variable is set, `c10d::ProcessGroupNCCL` initialize a `c10d::IntraNodeComm` for its ranks.
- If the setup is not suitable for intra-node comm (e.g. not all ranks are from the same node), the rendezvous logic guarantees all participants fall back consistently.
- `c10d::ProcessGroupNCCL::allreduce` consults `c10d::IntraNodeComm` whether to use intra-node allreduce and carries out the communication accordingly.
We currently detect two types of topoloies from the nNVLink connection mesh:
- Fully connected: all GPU pairs has direct NVLink connection (e.g. NVSwitch or fully connected sub-set of hybrid cube mesh)
- `msg <= 256KB`: one-shot allreduce.
- `256KB < msg <= 10MB`: two-shot allreduce.
- `msg > 10MB`: instructs the caller to fallback to NCCL.
- Hybrid cube mesh
- `msg <= 256KB`: one-shot allreduce.
- `msg > 256KB`: instructs the caller to fallback to NCCL.
## Next Steps
- Fine tune algo selection based on GPU model, topology, link speed.
- Potentially optimize the two-shot allreduce impl. Accroding to FasterTransformer, two-shot allreduce is preferred until 50MB. There might be room for improvement, but PyTorch does impose more constraints:
- FasterTransformer uses a single process to drive multiple devices. It can use `cudaDeviceEnablePeerAccess` enable device-level peer access.
- PyTorch uses multiple process to drive multiple devices. With cuda IPC, a device can only share a specific region to other devices. This means extra copies may be unavoidable.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114001
Approved by: https://github.com/yf225
## Summary
This PR added 3 intra-node GPU allreduce algorithms to PyTorch:
- One-shot allreduce (inspired by FasterTransformer): all ranks simultaneously read and accumulate data from other ranks.
- Two-shot allreduce (inspired by FasterTransformer): all ranks simultanesouly read and accumulate `1 / world_size` data from other ranks. Then all ranks read accumulated data from other ranks. (effectively one-shot reduce-scatter + one-shot all-gather).
- Hybrid cube mesh allreduce (original): a one-shot allreduce variant that avoids transmission over PCIe on HCM topology.
## Micro Benchmarks



## Details
The intra-node algos are organized behind `c10d::IntraNodeComm`, which is responsible for:
- Managing handshaking and cuda IPC handle exchange among ranks.
- Querying NVLink connection and detecting topology.
- Performing algo selection based on available info.
- Launching the selected allreduce kernel.
`c10d::IntraNodeComm` is integrated into `c10d::ProcessGroupNCCL` as follows:
- When the `ENABLE_INTRA_NODE_COMM` environment variable is set, `c10d::ProcessGroupNCCL` initialize a `c10d::IntraNodeComm` for its ranks.
- If the setup is not suitable for intra-node comm (e.g. not all ranks are from the same node), the rendezvous logic guarantees all participants fall back consistently.
- `c10d::ProcessGroupNCCL::allreduce` consults `c10d::IntraNodeComm` whether to use intra-node allreduce and carries out the communication accordingly.
We currently detect two types of topoloies from the nNVLink connection mesh:
- Fully connected: all GPU pairs has direct NVLink connection (e.g. NVSwitch or fully connected sub-set of hybrid cube mesh)
- `msg <= 256KB`: one-shot allreduce.
- `256KB < msg <= 10MB`: two-shot allreduce.
- `msg > 10MB`: instructs the caller to fallback to NCCL.
- Hybrid cube mesh
- `msg <= 256KB`: one-shot allreduce.
- `msg > 256KB`: instructs the caller to fallback to NCCL.
## Next Steps
- Fine tune algo selection based on GPU model, topology, link speed.
- Potentially optimize the two-shot allreduce impl. Accroding to FasterTransformer, two-shot allreduce is preferred until 50MB. There might be room for improvement, but PyTorch does impose more constraints:
- FasterTransformer uses a single process to drive multiple devices. It can use `cudaDeviceEnablePeerAccess` enable device-level peer access.
- PyTorch uses multiple process to drive multiple devices. With cuda IPC, a device can only share a specific region to other devices. This means extra copies may be unavoidable.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/114001
Approved by: https://github.com/yf225
This PR introduces a native version of c10d_functional ops. The main goal is to add collective support in AOTInductor and allow collective ops to work in multi-threaded native runtimes.
The native version also incorporated API improvements we wished to implement in Python c10d_functional:
- Removed `ranks` and `group_size` from collective op signatures which were proven to be redundant.
- Use tensor storage as opposed to `void*` to resolve in-flight work.
The native process group registration/resolution mechansim is only used for native c10d_functional in the PR. It will become the single source of truth in upcoming PRs.
The upcoming PRs will implement Inductor/AOTInductor support for c10d_functional, after which native c10d_functional will replace Python c10d_functional.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110570
Approved by: https://github.com/wanchaol